Organic EL display device

Abstract

The purpose of the present invention is to provide an organic EL display device with minimal brightness unevenness.　This organic EL display device is provided with a substrate, a first electrode, a pixel division layer, light-emitting pixel and a second electrode, wherein the pixel division layer contains (a) an organic black pigment and / or a mixed-color organic black pigment, and (b) silica particles with a primary particle diameter of 5-30 nm and an aspect ratio (long axis / short axis) of 1.0-1.5.

Description

[Technical Field]

[0001] This invention relates to an organic EL display device. [Background technology]

[0002] Many products incorporating organic electroluminescent (EL) displays have been developed, including smartphones, televisions, and in-car monitors. Organic EL displays are self-emissive displays that emit light using the energy generated by the recombination of electrons injected from the cathode and holes injected from the anode. Each light-emitting pixel is formed in the opening of a patterned pixel division layer that functions as an insulating layer.

[0003] In recent years, a technique has attracted attention for improving the visibility and contrast of organic EL display devices by blackening the pixel division layer to suppress color mixing due to light leakage to adjacent light-emitting pixels and reflection of external light such as sunlight. As a material for forming a black pixel division layer, for example, a negative-type photosensitive composition containing an organic black pigment, a polyimide resin, and a fluorene-based acrylate compound is disclosed in Patent Document 1. According to Patent Document 1, it is possible to form a pixel division layer that combines high light-shielding properties with a low taper angle. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2018 / 181311 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, when an organic EL display device having a black pixel division layer is fabricated using the negative-type photosensitive composition disclosed in Patent Document 1, there is a problem of large brightness unevenness. [Means for solving the problem]

[0006] The present invention relates to an organic EL display device including a substrate, a first electrode, a pixel division layer, a light-emitting pixel, and a second electrode, wherein the pixel division layer contains (a) an organic black pigment and / or a mixed-color organic black pigment, and (b) silica particles having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5.

Effects of the Invention

[0007] According to the present invention, an organic EL display device with less luminance unevenness is provided.

Brief Description of the Drawings

[0008] [Figure 1] It is a cross-sectional view of a TFT substrate in an organic EL display device cited as a specific example of an embodiment of the present invention. [Figure 2] It is a manufacturing process of an organic EL display device including a pixel division layer forming process in all examples and comparative examples. [Figure 3] It is a schematic diagram showing the maximum aperture width W1 and the minimum aperture width W2 in the aperture of a substrate for aperture width evaluation in all examples and comparative examples. [Figure 4] It is a pixel division layer / spacer layer forming substrate in Example 12, and is a schematic diagram when viewed from the film surface side and when viewed from the cross-section.

Modes for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described in detail. A numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. The pixel division layer means the pixel division layer included in the organic EL display device and does not include the black matrix of the liquid crystal display device. Visible light means light in the region of wavelengths of 380 nm or more and less than 780 nm, and near ultraviolet light means light in the region of wavelengths of 200 nm or more and less than 380 nm. Light shielding means a function of reducing the intensity of transmitted light as compared with the intensity of light incident in the direction perpendicular to the cured film, and light shielding property means the degree of shielding visible light. The photosensitive composition means a photosensitive composition having photosensitivity to near ultraviolet light and being of an alkali-developable type. The weight average molecular weight (Mw) is a value analyzed by gel permeation chromatography using tetrahydrofuran as a carrier and converted using a calibration curve based on standard polystyrene.

[0010] "C.I." used for the names of some colorants is an abbreviation of Colour Index Generic Name. Based on the Colour Index published by The Society of Dyers and Colourists, for colorants registered in the Colour Index, the Colour Index Generic Name represents the chemical structure and crystal form of the pigment or dye. Note that carbon black classified as C.I. Pigment Black 7 etc. is classified as an inorganic black pigment. The solid content means the ratio (weight %) of components excluding the solvent and water in the photosensitive composition.

[0011] As a result of the present inventors' verification of the above-mentioned problems, usually, the light-emitting pixels are composed of at least three colors of blue, red, and green. In the green pixels that are designed with a high specific visibility and the shortest short diameter of the aperture, it was found that the in-plane variation of the light-emitting pixel size is particularly easily visually recognized by the user as unevenness in luminance. The specific visibility here means the intensity with which the human eye feels the brightness for each wavelength of light. Also, due to the laminated structure of the light-emitting element, the light-emitting pixel size is determined by the aperture width of the aperture of the pixel division layer. Therefore, a large in-plane variation in the aperture width was considered to be the cause of the luminance unevenness.

[0012] In light of the above, the inventors have conducted thorough studies and found that adopting the following configuration is particularly effective in solving the aforementioned problems. In other words, the present invention relates to an organic EL display device comprising a substrate, a first electrode, a pixel splitting layer, an emissive pixel, and a second electrode, wherein the pixel splitting layer contains (a) an organic black pigment and / or a mixed organic black pigment, and (b) silica particles having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5.

[0013] The organic EL display device of the present invention comprises a substrate, a first electrode, a pixel division layer, a light-emitting pixel, and a second electrode. Figure 1 shows a cross-sectional view of a TFT substrate in an organic EL display device, which is a specific example of an embodiment of the present invention.

[0014] A matrix of bottom-gate or top-gate thin-film transistors 1 (hereinafter abbreviated as TFT1) is arranged on the surface of the substrate 6, and a TFT insulating layer 3 is formed covering the TFT1 and the wiring 2 connected to the TFT1. Furthermore, a planarization layer 4 is formed on the surface of the TFT insulating layer 3, and the planarization layer 4 is provided with contact holes 7 that open up to connect the first electrode 5 to the wiring 2. The first electrode 5 is patterned on the surface of the planarization layer 4 and is connected to the wiring 2. A pixel division layer 8 is formed so as to surround the periphery of the pattern of the first electrode 5. An opening is provided in the pixel division layer 8, and an emissive pixel 9 containing organic EL emissive material is formed in the opening, and a second electrode 10 is deposited in a film that covers the pixel division layer 8 and the emissive pixel 9. After sealing the TFT substrate with the above laminated structure under vacuum, if a voltage is applied to the emissive pixel portion, it can be made to emit light as an organic EL display device.

[0015] The shape of the aperture of the pixel division layer 8 is not particularly limited and may be square, rectangular, or elliptical. The aperture width of the aperture may be appropriately determined by the size of the light-emitting pixel 9 described later, for example, the minor axis may be 10 to 50 μm. The optical density per 1 μm of film thickness of the pixel division layer of the organic EL display device of the present invention is preferably 0.5 or higher, and more preferably 0.7 or higher, in order to suppress external light reflection and enhance the value as a display device. In order to suppress brightness unevenness, it is preferably 1.5 or lower, and more preferably 1.2 or lower. The optical density per 1 μm of film thickness referred to here means the value obtained by measuring the incident light intensity and transmitted light intensity using an optical densitometer (X-Rite 361T, manufactured by X-Rite Corporation), dividing the value calculated from the following formula by the film thickness, and rounding the result to the second decimal place. A higher optical density indicates higher light shielding performance.

[0016] Optical density = log 10 (I0 / I) I0: Incident light intensity I: transmitted light intensity.

[0017] The thickness of the pixel division layer 8 is usually formed to be 1 to 4 μm. The taper angle of the edge of the pixel division layer at the boundary with the opening of the pixel division layer is preferably 50° or less, and more preferably 40° or less, in order to improve the film formation of the second electrode 10 and suppress non-illumination of the light-emitting pixels. It is preferably 15° or more, and more preferably 20° or more, in order to suppress the decrease in light shielding performance at the edge of the pixel division layer.

[0018] To reduce brightness unevenness, the pixel division layer is preferably formed by a photolithography method using an alkaline-developable photosensitive composition. The photosensitive composition may be either a negative-type or positive-type photosensitive composition, but a negative-type photosensitive composition is preferred because it has high exposure sensitivity and excellent formation and productivity of a highly light-shielding pixel division layer. In other words, the pixel division layer of the organic EL display device of the present invention is preferably a cured film formed from a negative-type photosensitive composition.

[0019] A preferred method for forming a pixel splitting layer using a negative-type photosensitive composition includes a coating step of applying the negative-type photosensitive composition to obtain a coated film, an exposure step of pattern exposure of activation lines through a negative-type exposure mask to obtain an exposure film having exposed and unexposed areas in the plane, a developing step of developing with an alkaline developer to remove the film in the unexposed areas to obtain a developed film, and a curing step of heat-curing to obtain a cured film.

[0020] As the coating apparatus used in the coating process, a spin coater or a slit coater can be preferably used due to its excellent thin-film coating properties. After coating, pin gap pre-baking or contact pre-baking may be performed. The pre-baking temperature is preferably 50 to 150°C, and the pre-baking time is preferably 30 seconds to 5 minutes.

[0021] Examples of exposure equipment used in the exposure process include steppers, mirror projection mask aligners (MPAs), and parallel light mask aligners (PLAs). Examples of activation rays used during exposure include the j-line (wavelength 313 nm), i-line (wavelength 365 nm), h-line (wavelength 405 nm), or g-line (wavelength 436 nm) of a mercury lamp, with the i-line or a mixed line containing at least the i-line being more preferred. Examples of negative exposure masks include masks in which a thin film with shielding properties made of a metal such as chromium is deposited in a pattern on one side surface of a substrate that is light-transmitting at the exposure wavelength, such as glass, quartz, or film. By allowing the activation rays to pass through only the openings and performing pattern exposure, an exposure film having exposed and unexposed areas in its plane can be obtained.

[0022] In this context, "exposed area" refers to the part that has been exposed to light, while "unexposed area" refers to the part that has not been exposed to light.

[0023] Examples of development methods in the development process include shower, dipping, and paddle methods, and a method of immersing the exposed film for 10 seconds to 3 minutes is also used. The paddle method is preferred for improving the in-plane uniformity of the aperture width. A 1.0 to 2.5 wt% aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH) is preferred as the alkaline developer, and a commercially available product is, for example, 2.38 wt% TMAH (manufactured by Tama Chemical Industry Co., Ltd.). After the development process, a washing treatment with a shower of deionized water and / or a water removal treatment with air spray may be added.

[0024] In the curing process, the developing film is heat-cured by heating, and at the same time, moisture and other substances are evaporated to obtain a cured film. Examples of heating devices include hot air ovens and IR ovens. The heating temperature is preferably 200 to 350°C under atmospheric pressure, and more preferably 220 to 280°C. Since the deformation and / or fusion of component (b) occurs at 800 to 1200°C, the primary particle size and aspect ratio of component (b) can be maintained before and after the curing process by setting the heating temperature to a range of 350°C or lower. The primary particle size and aspect ratio of component (b) will be described later.

[0025] The organic EL display device of the present invention preferably further comprises a spacer layer on at least a portion of the surface of the pixel division layer. The spacer layer is a columnar layer formed in the panel display portion of the organic EL display device with a formation area of ​​30% or less of the formation area of ​​the pixel division layer. When forming the light-emitting pixels 9 described later, the spacer layer reduces the area in contact between the pixel division layer and the deposition mask, that is, it provides a spacer effect, suppressing defects in the organic EL element, improving yield, and increasing the productivity of the organic EL display device. Photolithography is preferred as the method for forming the spacer layer, and for example, the same method as the method for forming the pixel division layer described above can be applied. The thickness of the spacer layer is preferably 0.5 to 2.0 μm.

[0026] The light-emitting pixel 9 is fabricated by arranging different types of pixels, each having a peak emission wavelength in the blue, red, and green regions, which are the three primary colors of light, across its entire surface. Alternatively, blue, red, and green color filters may be combined and arranged on the front surface of the display unit as a separate laminated member. The peak wavelengths of the red region that are normally displayed are 560-700 nm, the peak wavelength of the blue region is 420-500 nm, and the peak wavelength of the green region is 500-550 nm. However, in the organic EL display device of the present invention, the types of light-emitting pixels are not particularly limited, and the emitted light may have any peak wavelength. As the organic EL light-emitting material constituting the light-emitting pixel, a material that combines a light-emitting layer with a hole transport layer and / or an electron transport layer can be suitably used.

[0027] One method for patterning light-emitting pixels is the mask deposition method. The mask deposition method is a method of patterning by depositing an organic compound using a deposition mask. Specifically, it involves placing a deposition mask with the desired pattern as an opening on the substrate side and performing deposition. To obtain a high-precision deposition pattern, it is important to ensure that a highly flat deposition mask is in close contact with the substrate. Generally, techniques such as applying tension to the deposition mask or using magnets placed on the back of the substrate to adhere the deposition mask to the substrate can be used. Methods for manufacturing deposition masks include etching, mechanical polishing, sandblasting, sintering, laser processing, and the use of photosensitive resins. However, when forming finer patterns, etching or electroforming is preferable due to their superior processing accuracy.

[0028] As the first electrode 5, conductive metal oxides such as zinc oxide, tin oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO) can be used, and among these, ITO can be preferably used because of its excellent transparency and conductivity. As a method for patterning ITO, first, ITO is deposited over the entire surface by sputtering, and then a positive-type resist material for etching is patterned by photolithography to obtain a resist pattern on the ITO film.

[0029] Next, a method is used in which only the ITO film in the areas where the resist pattern is not formed is removed with an etching solution at a liquid temperature of 20 to 60°C, then the resist pattern is removed with a resist stripping solution at a liquid temperature of 20 to 60°C, and further heat treatment is performed as needed to achieve the desired degree of crystallinity. Here, ITO refers to so-called amorphous ITO. As the positive-type resist material for etching, a positive-type photosensitive composition containing an alkali-soluble novolac resin can be used. As the etching solution, an aqueous solution containing nitric acid and hydrochloric acid or an aqueous solution of oxalic acid can be used, and commercially available products include, for example, ITO-101N (manufactured by Kanto Chemical Co., Ltd.), "Escreen" (registered trademark) IS-2, and IS-3 (all manufactured by Sasaki Chemical Co., Ltd.).

[0030] Organic amine-based aqueous solutions can be used as resist stripping solutions. Commercially available examples include "Unlast" (registered trademark) M6, M6B, TN-1-5, and M71-2 (all manufactured by Sanwaka Pure Chemical Industries). When the organic EL display device of the present invention is a top-emission type organic EL display device, the first electrode 5 may have a laminated structure of ITO / silver alloy / ITO in order to improve light reflectivity and adhesion to the substrate.

[0031] The second electrode 10 can be made of any material as long as it is a layer that can function as an electrode. Specific examples of the second electrode 10 include, if the organic EL display device of the present invention is a bottom-emission type organic EL display device, a layer made of aluminum is preferably used due to its excellent light reflectivity. If it is a top-emission type organic EL display device, a layer made of a silver alloy composed of silver / magnesium is preferably used due to its excellent light transmittance. The second electrode can be obtained by full-surface film deposition using a sputtering method.

[0032] The light extraction direction of the organic EL display device of the present invention is not particularly limited; it may be a bottom-emission type organic EL display device in which the light emitted from the light-emitting pixels is extracted towards the substrate side via the substrate 6, or it may be a top-emission type organic EL display device in which the light emitted is extracted to the opposite side of the substrate 6 via the first electrode.

[0033] If a rigid plate-shaped substrate such as glass is used for the substrate 6, a rigid-type organic EL display device that cannot be bent can be made. As for the glass, alkali-free glass with an alkali metal element content of less than 0.5% and silicon as the main component can be suitably used. In particular, glass with a small coefficient of thermal expansion and excellent dimensional stability in high-temperature processes of 250°C or higher is preferred. Examples include OA-10G, OA-11 (both manufactured by Nippon Electric Glass Co., Ltd.), and AN-100 (manufactured by Asahi Glass Co., Ltd.), and its thickness is usually 0.1 to 0.5 mm from the viewpoint of physical durability.

[0034] On the other hand, if a flexible substrate is used for the substrate 6, a flexible type of organic EL display device that can be bent can be made. As the flexible substrate, a substrate made of polyimide resin, which has high flexibility and excellent mechanical strength, can be suitably used. One method for producing this is to apply a solution containing polyamic acid to the surface of a temporary support, then heat it to imide the polyamic acid and convert it into polyimide resin, and then peel off the temporary support with a laser or the like. The polyamic acid used in this case can be synthesized by reacting a tetracarboxylic dianhydride and a diamine compound in an amide solvent such as N-methyl-2-pyrrolidone, and among these, polyamic acid having residues of aromatic tetracarboxylic dianhydride and aromatic diamine compound is preferred because it has a small coefficient of thermal expansion and excellent dimensional stability. A specific example is polyamic acid having residues of 3,3',4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine. Its thickness is usually 10 to 40 μm, which makes the substrate 6 thinner compared to when alkali-free glass is used.

[0035] The pixel division layer of the organic EL display device of the present invention contains (a) an organic black pigment and / or a mixed organic black pigment (hereinafter sometimes referred to as component (a)). Component (a) has the effect of providing light-shielding properties to the pixel division layer.

[0036] Examples of organic black pigments include benzodifuranone-based black pigments, perylene-based black pigments, and azomethine-based black pigments.

[0037] Examples of benzodifuranone-based black pigments include the pigment disclosed in International Publication No. 2009 / 010521. As commercially available benzodifuranone-based black pigments consisting of the compound represented by formula (3) described later, Irgaphor Black® S0100CF and Experimental Black 582 (both manufactured by BASF) can be preferably used.

[0038] Examples of perylene-based black pigments include CI Pigment Black 31, CI Pigment Black 32, benzimidazole perylenetetracarboxylic acid or its derivatives, and the pigments disclosed in International Publication No. 2005 / 078023. Commercially available products include Spectrasense® Black S0084, L0086, K0087, and K0088 (all manufactured by BASF).

[0039] Examples of azomethine-based black pigments include the pigment disclosed in U.S. Patent Application Publication No. 2002-121228. As a commercially available product, Chromofine Black A1103 (manufactured by Dainichi Seika Kogyo Co., Ltd.) can be used.

[0040] A mixed organic black pigment is a pigment mixture containing (a-1) at least one organic pigment selected from organic yellow pigment, organic red pigment, and organic orange pigment (hereinafter sometimes referred to as (a-1) component) and (a-2) at least one organic pigment selected from organic blue pigment and organic purple pigment (hereinafter sometimes referred to as (a-2) component), wherein the content of (a-2) component is 20% by weight or more of the total amount of (a-1) component and (a-2) component.

[0041] Examples of organic yellow pigments include CI Pigment Yellow 24, 120, 138, 139, 151, 175, 180, 185, 181, 192, 193, and 194. Examples of organic orange pigments include CI Pigment Orange 13, 36, 43, 60, 61, 62, 64, 71, and 72. Examples of organic red pigments include CI Pigment Red 122, 123, 149, 178, 177, 179, 180, 189, 190, 202, 209, 254, 255, and 264. Examples of organic blue pigments include CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:6, 16, 25, 56, 57, 60, 61, 64, 65, 66, 75, 79, and 80. Examples of organic purple pigments include CI Pigment Violet 19, 23, 29, 32, and 37.

[0042] Of the components corresponding to component (a) above, in order to reduce brightness unevenness, it is preferable that component (a) contained in the pixel splitting layer of the organic EL display device of the present invention contains an organic black pigment, and that the organic black pigment contains a compound represented by formula (1) or formula (2) and / or its isomer. It is more preferable that component (a) contained in the pixel splitting layer contains a compound represented by formula (3) or its isomer. The compounds represented by formulas (1) to (3) can be synthesized and obtained as pigments by reacting 2,5-dihydroxy-1,4-benzenediacetic acid with isatin or a derivative thereof under an acidic catalyst.

[0043] [ka]

[0044] [ka]

[0045] In equations (1) and (2), R 1 ~R 10 Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

[0046] [ka]

[0047] (a) The component corresponding to component (a) may be subjected to micronization treatment by known methods such as solvent salt milling or acid paste method in order to further suppress brightness unevenness. When micronizing benzodifuranone-based black pigments, it may be easier to suppress brightness unevenness by coexisting with the compound represented by formula (4) or a salt thereof and adsorbing it onto the pigment surface.

[0048] [ka]

[0049] In equation (4), n and m represent integers, each independently ranging from 0 to 2. However, the condition n+m≧1 must be met. Furthermore, if component (a) contains a benzodifuranone-based black pigment, it is preferable to have a coating layer containing silica on the surface of the pigment in order to improve developability and suppress development residue at the opening. The silica contained in the coating layer here is not component (b), but rather a part of component (a).

[0050] (a) The content of component is preferably 1% by weight or more, and more preferably 10% by weight or more, in the pixel splitting layer to achieve high light shielding properties. It is preferably 50% by weight or less, and more preferably 30% by weight or less, in order to reduce brightness unevenness.

[0051] The pixel division layer of the organic EL display device of the present invention contains (b) silica particles (hereinafter sometimes referred to as component (b)) having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5. Here, "primary particle diameter" refers to the major axis of the particle, and "silica particles with a primary particle diameter of 5 to 30 nm" refers to particles whose primary particle diameter falls within the range of 5 to 30 nm. Here, "aspect ratio (major axis / minor axis)" refers to the value obtained by dividing the major axis by the minor axis of the primary silica particles and rounding the result to the second decimal place, and "silica particles with an aspect ratio of 1.0 to 1.5" refers to particles whose aspect ratio falls within the range of 1.0 to 1.5. (b) Component (b) enhances the uniformity of the aperture width and reduces brightness unevenness.

[0052] Here, silica particles refer to particles in which the SiO2 content is 90% or more by weight excluding water, particles made of silicon dioxide (anhydrous silicic acid), particles made of silicon dioxide hydrate (hydrated silicic acid), and particles made of quartz glass. The form in which hydrated silicic acid exists is not particularly limited, and particles made of orthosilicic acid, metasilicic acid, and / or metadicilic acid also fall under the category of silica particles as used herein. Weight excluding water means the weight of the particle minus the weight of the water contained in the particle.

[0053] However, in core-shell type composite particles, particles that do not contain SiO2 as the core, such as particles made of organic polymers, or surface treatment agents and coating layers applied as shells to at least a portion of the surface of organic or inorganic pigments, are defined as not being silica particles on their own, regardless of the purity of SiO2, even if they contain SiO2. On the other hand, core-shell type composite particles that contain SiO2 as the core and have a purity of SiO2 of 90% by weight or more of the weight excluding water are defined as being silica particles. That is, component (b) is packed in a form dispersed as particles in the pixel division layer. The structure of the particles of component (b) is not particularly limited and may have internal voids.

[0054] Silica particles other than those made of silicon dioxide, silicon dioxide hydrate, and quartz glass mentioned above include, for example, silica particles made of a silicon-metal composite oxide in which the purity of SiO2 is 90% or more by weight excluding water. Examples of metals here include zirconium, titanium, and cerium. However, silica particles containing hafnium atoms are defined as a mixture of silica particles and component (c).

[0055] To further reduce brightness unevenness in organic EL display devices, component (b) more preferably contains silica particles with a primary particle diameter of 5 to 20 nm, and even more preferably contains silica particles with a primary particle diameter of 5 to 15 nm. It is more preferable to contain silica particles with an aspect ratio of 1.0 to 1.3, and even more preferable to contain silica particles with an aspect ratio of 1.0 to 1.2. Note that when the aspect ratio is 1.0, it can be considered as perfectly spherical silica particles.

[0056] For silica particles other than component (b), the pixel division layer and spacer layer are thinly sliced ​​and used as observation samples. The cross-sections are polished to improve smoothness, preferably by pretreatment by ion milling, more preferably by focused ion beam (FIB) processing. By analyzing the area located in the film depth direction from the outermost layer of the pixel division layer or spacer layer in the range of 0.2 to 0.8 μm using transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX), the elements constituting the particles can be identified from elemental mapping information. Transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS) or scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDX) can also be used for analysis.

[0057] Specifically, by observing the sample using a transmission electron microscope-energy-dispersive X-ray spectroscopy (TEM-EDX) at a magnification of 50,000x and measuring the resulting image using the image analysis type particle size distribution analyzer "Mac-View" (manufactured by MOUNTECH), it is possible to distinguish between silica particles corresponding to component (b) and those that do not. That is, 30 silica particles are randomly selected from the TEM image in the cross-section of the pixel division layer, and the major axis, minor axis, and aspect ratio of each are measured. Silica particles with a major axis (nm) of 5 to 30 nm and an aspect ratio in the range of 1.0 to 1.5 are defined as component (b). Note that if the minor axis and major axis of a single silica particle are equal, i.e., if it is a perfect circle, its diameter is considered the major axis. (b) As representative values ​​indicating the characteristics of silica particles corresponding to component (b), the average value of the primary particle diameter, i.e., the average value of the major axis, rounded to the first decimal place, and the average value of the aspect ratio, i.e., the average value of the aspect ratio of individual silica particles corresponding to component (b), rounded to the second decimal place, are used. Here, SiO2 components that have contact with the surface of particles such as polymer particles, organic pigments and / or inorganic pigments are excluded from the analysis. The major axis and aspect ratio of silica particles contained in the spacer layer can be measured in the same manner.

[0058] Furthermore, the pixel splitting layer of the organic EL display device of the present invention may also contain silica particles that do not fall under component (b), i.e., silica particles having a primary particle diameter of less than 5 nm or greater than 30 nm, or silica particles having an aspect ratio (major axis / minor axis) greater than 1.5. Examples of silica particles that do not fall under component (b) include “AdmaFine” (registered trademark) SO-E2, SO-E4 (both manufactured by Admatec Co., Ltd.), KE-P10, and KE-S10 (both manufactured by Nippon Shokubai Co., Ltd.).

[0059] The pixel splitting layer of the organic EL display device of the present invention may further contain particles that do not fall under the category of silica particles as defined herein, with SiO2 content at a ratio of less than 90% by weight of the weight excluding water. Examples of particles that do not fall under the category of silica particles include "ATLAS" (registered trademark) 100 (manufactured by CABOT Corporation), which is an organic-inorganic composite particle with a silica:polymer ratio of 70:30 by weight, as disclosed in Japanese Patent Application Publication No. 2018-97251.

[0060] The average primary particle diameter of the silica particles contained in the pixel splitting layer of the organic EL display device of the present invention is preferably 5 to 30 nm, and more preferably 5 to 25 μm, from the viewpoint of suppressing brightness unevenness. The average aspect ratio (major axis / minor axis) is preferably 1.0 to 1.3, and more preferably 1.0 to 1.2. That is, even if the pixel splitting layer of the organic EL display device of the present invention contains silica particles that do not fall under component (b), it is preferable that the average primary particle diameter of all contained silica particles is 5 to 30 nm and the average aspect ratio (major axis / minor axis) is 1.0 to 1.3. The silica particles referred to here include both component (b) and silica particles that do not fall under component (b). The average primary particle diameter referred to here is the value obtained by rounding the first decimal place of the average major axis of all silica particles obtained by randomly acquiring 30 images using the image analysis type particle size distribution analyzer "Mac-View" (manufactured by MOUNTECH), based on images taken by observing a cross section located in the range of 0.2 to 0.8 μm in the film depth direction from the outermost layer of the pixel division layer under the conditions of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) at a magnification of 50,000x, as described above. The "average aspect ratio (major axis / minor axis)" referred to here is the value obtained by rounding the second decimal place of the average value obtained by averaging the major axis divided by the minor axis for each primary particle of all silica particles obtained by randomly acquiring 30 images from the same image. Silica particles with an average primary particle diameter of 5-30 nm refer to particles whose average primary particle diameter falls within the range of 5-30 nm, and silica particles with an average aspect ratio of 1.0-1.3 refer to particles whose average aspect ratio falls within the range of 1.0-1.3.

[0061] The specific surface area of the component (b) corresponding to the above primary particle diameter is preferably 50 to 500 m 2 / g, more preferably 200 to 400 m 2 / g. The specific surface area referred to here means the specific surface area measured by the BET method using nitrogen as the adsorption gas. The surface of the component (b) may be porous or non-porous, and may have an internal surface area.

[0062] Examples of the functional group that the component (b) has on its surface include reaction residues of surface modification groups containing ethylenically unsaturated double bond groups, silanol groups, alkoxysilyl groups, trialkylsilyl groups, and diphenylsilyl groups. Among them, in order to further reduce unevenness in luminance, it is preferable to have reaction residues of surface modification groups containing ethylenically unsaturated double bond groups. The reaction residue of the surface modification group containing an ethylenically unsaturated double bond group referred to here means a group remaining after the ethylenically unsaturated double bond group of the surface modification group containing an ethylenically unsaturated double bond group has undergone a radical polymerization reaction by light and / or heat. It is more preferable that the component (b) contains silica particles having reaction residues of surface modification groups containing ethylenically unsaturated double bond groups on the particle surface, and the reaction residues of the surface modification groups containing ethylenically unsaturated double bond groups have a structure represented by formula (19) and / or a structure represented by formula (20). The reaction residue of the surface modification group containing an ethylenically unsaturated double bond group is more preferably a residue generated by a radical polymerization reaction with a compound having two or more radical polymerizable groups in the molecule, which will be described later.

[0063] [Chemical formula]

[0064] In formula (19), R 16 represents a hydrogen atom or a methyl group. R 17 represents a divalent hydrocarbon group having 1 to 7 carbon atoms. j and k are integers and each independently represents 0 or 1. However, when j is 1, k is 1. * 1 represents the bonding site with a carbon atom. * 2R represents the bonding site between silicon atoms and oxygen atoms on the particle surface of silica particles. 18 The symbol represents an alkyl group with 1 to 3 carbon atoms. m and n are integers, where m represents 1 to 3 and n represents 0 to 2. However, m + n = 3.

[0065] [ka]

[0066] In formula (20), R 19 R represents a hydrogen atom or a methyl group. 20 * represents an oxyalkylene group with 1 to 3 carbon atoms. r is an integer, representing 1 to 4. 3 This represents the bonding site with a carbon atom. * 4 This represents the bonding site between silicon atoms and oxygen atoms on the surface of silica particles.

[0067] Component (b), having the structure represented by formula (19), can be obtained by introducing a surface-modifying group derived from an organic alkoxysilane compound having an ethylenically unsaturated double bond group through a dehydration condensation reaction with a silanol group on the surface of silica particles, and then radically polymerizing the ethylenically unsaturated double bond group contained in the surface-modifying group using light and / or heat.

[0068] Examples of organic alkoxysilane compounds having an ethylenically unsaturated double bond group include vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, allyltrimethoxysilane, and allyltriethoxysilane.

[0069] Component (b), having a structure represented by formula (20) for the reaction residue, can be obtained by introducing a surface-modifying group derived from an isocyanate compound having an ethylenically unsaturated double bond group through a urethane reaction with silanol groups on the surface of silica particles, and then radically polymerizing the ethylenically unsaturated double bond group contained in the surface-modifying group using light and / or heat. Examples of isocyanate compounds having an ethylenically unsaturated double bond group include 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-(2-methacryloyloxyethyloxy)ethyl isocyanate.

[0070] Furthermore, by sequentially modifying the surface of silica particles with a surface modification group derived from an organic alkoxysilane compound having an ethylenically unsaturated double bond group and a surface modification group derived from an isocyanate compound having an ethylenically unsaturated double bond group, component (b) having a structure represented by formula (19) and a structure represented by formula (20) can be obtained.

[0071] To improve the dispersion stability of component (b) in a negative-type photosensitive composition for forming a pixel splitting layer, it is preferable that component (b) has a trialkylsilyl group, and more preferably a trimethylsilyl group. The trimethylsilyl group can be introduced into component (b) by converting hydrogen atoms in the surface silanol groups of silica particles to trimethylsilyl groups using a trimethylsilylation agent. Examples of trimethylsilylation agents include hexamethyldisilazane and trimethylalkoxysilane, which can be introduced by deammonia reaction and dehydration condensation reaction, respectively. By improving the dispersion stability of component (b), it may be possible to reduce brightness unevenness more stably.

[0072] To further reduce brightness unevenness, component (b) preferably contains silica particles having sodium atoms. Possible forms of sodium atoms include, for example, ions (Na +Examples include salts with silanol groups (Si-ONa). The sodium atom content is preferably 100 to 5000 ppm by weight in component (b). Silica particles containing sodium atoms can be synthesized under alkaline conditions by the reaction of sodium silicate, which is strongly alkaline as a silicon source, and mineral acid, which is strongly acidic. The sodium atoms in the silica particles can be detected at the central position corresponding to the intersection of the long axis and short axis in imaging of the cross-section of the primary particle using the aforementioned TEM-EDX.

[0073] (b) The content of component (b) in the pixel splitting layer is preferably 1 to 50% by weight in terms of SiO2, and more preferably 5 to 20% by weight, in order to suppress unevenness in brightness. Similarly, for all silica components in the pixel splitting layer, it is preferably 1 to 50% by weight in terms of SiO2, and more preferably 7 to 30% by weight. The content in terms of SiO2 referred to here means the content calculated based on the common technical knowledge of those skilled in the art, excluding the weight of water in the silica particles which fluctuates due to thermal history.

[0074] Furthermore, the content of component (b) per 100 parts by weight of component (a) is preferably 20 to 70 parts by weight in terms of SiO2, and more preferably 30 to 50 parts by weight, in order to reduce brightness unevenness. In other words, in the organic EL display device of the present invention, it is preferable that the content of component (b) relative to component (a) in the pixel splitting layer is 20 to 70 parts by weight in terms of SiO2.

[0075] To further reduce brightness unevenness, the pixel splitting layer of the organic EL display device of the present invention preferably contains 1 to 50 ppm by weight of (c) hafnium atoms (hereinafter sometimes referred to as component (c)) in the pixel splitting layer, and more preferably contains 1 to 30 ppm by weight of (c) in the pixel splitting layer. Component (c) is preferably included in the pixel splitting layer as inorganic particles containing hafnium atoms.

[0076] Examples of inorganic particles containing component (c) include hafnium oxide (HfO2), composite oxides of a metal other than hafnium and hafnium, solid solutions of an oxide of a metal other than hafnium and hafnium oxide, hafnium oxynitride, composite oxynitrides of a metal other than hafnium and hafnium, and solid solutions of oxynitrides of a metal other than hafnium and hafnium oxynitride. Among these, hafnium oxide (HfO2) or composite oxides of a metal other than hafnium and hafnium are preferred in terms of their excellent effect in reducing brightness unevenness, and a composite oxide of zirconium and hafnium (ZrO2-HfO2) is more preferred.

[0077] As inorganic particles containing component (c), commercially available products available in powder form can be used, for example, Hafnium oxide P, R, and S (all manufactured by ATI METALS), and hafnium oxide fine particles (manufactured by Kojun Chemical Laboratory Co., Ltd.). Alternatively, in the process of preparing a pigment dispersion containing component (a) as described later, the surface of a pulverized media containing component (c) may be wet-polished with mechanical energy to produce fine particles, which are then co-dispersed with component (a) to ultimately contain component (c) in the resulting pixel separation layer.

[0078] The content of component (c) can be quantified by ICP (inductively coupled plasma) emission spectroscopy using a solution obtained by scraping a portion of the pixel division layer located in the film depth direction from the outermost layer to 0.2 to 0.8 μm, heating it to ash at a temperature of 800°C or higher in an electric furnace, further decomposing it with sulfuric acid, nitric acid, and hydrofluoric acid, and then heating and dissolving it with dilute nitric acid. The analytical instrument used is the PS3520VDDII (manufactured by Hitachi High-Tech Science).

[0079] To further reduce brightness unevenness, it is preferable that the pixel splitting layer of the organic EL display device of the present invention further contains (d) a phenol resin (hereinafter sometimes referred to as component (d)). Here, a phenol resin refers to a resin having repeating units having a phenol skeleton. Examples of component (d) include a resin having repeating units represented by formula (5) and a resin having repeating units represented by formula (6).

[0080] [ka]

[0081] [ka]

[0082] In equations (5) and (6), R 11 and R 12 Each of these independently represents either a methylene group or a CH-Ar group. Ar represents a phenyl group or a phenyl group with a substituent. * represents a bonding site.

[0083] (d) Component can be easily synthesized by known methods and can be obtained by reacting a compound having a phenol skeleton, such as phenol, o-cresol, m-cresol, p-cresol, or xylesol, with an aldehyde compound such as formaldehyde or benzaldehyde in the presence of an acidic catalyst.

[0084] (d) Component can be a commercially available product, for example, TRR5030G, TRR5010G, TR4020G, TR4080G, TR4000B, TRM30B20G, EP23F10G (all manufactured by Asahi Organic Chemicals Co., Ltd.). In the pixel splitting layer, at least a portion of component (d) may form a three-dimensional network structure by thermal crosslinking during the curing process.

[0085] To further reduce brightness unevenness, it is preferable that the pixel splitting layer of the organic EL display device of the present invention further contains a resin having repeating units having an acryloyl group or methacryloyl group and a trifluoromethyl group (CF3) (hereinafter sometimes referred to as component (e)). Furthermore, it is preferable that the repeating units having an acryloyl group or methacryloyl group and a trifluoromethyl group (CF3) have a structure represented by formula (7).

[0086] [ka]

[0087] In formula (7), R 13 * represents a hydrogen atom or a methyl group. * represents a bonding site.

[0088] A specific example of a repeating unit having an acryloyl group or a methacryloyl group and a trifluoromethyl group (-CF3) is the repeating unit represented by formula (8).

[0089] [ka]

[0090] In formula (8), R 14 and R 15 Each of these independently represents either a hydrogen atom or a methyl group. R 16 * represents a divalent hydrocarbon group. * represents a bonding site.

[0091] In formula (8), R 16 It is preferable that R is a residue of a compound having two epoxy groups in its molecule. 16 A preferred example is a structure having a cyclic structure represented by formulas (9) to (11).

[0092] [ka]

[0093] In equation (9), * represents the bonding site with the oxygen atom.

[0094] [ka]

[0095] In equation (10), * represents a bonding site with an oxygen atom.

[0096] [ka]

[0097] In equation (11), * represents a bonding site with an oxygen atom.

[0098] (e) As a method for obtaining component (e), for example, in the first step, the epoxy group of a compound having two epoxy groups in its molecule is reacted with acrylic acid or methacrylic acid. In the second step, the hydroxyl group produced by ring-opening of the epoxy group is reacted with a dicarboxylic acid anhydride having a trifluoromethyl group. It is desirable to use a correlation transfer catalyst to improve the reaction rate, and commercially available examples include tetraalkylammonium bromide and tetraalkylammonium chloride.

[0099] The pixel splitting layer of the organic EL display device of the present invention may contain, in addition to resins and dispersants other than components (d) and (e), cured products of compounds having two or more radical polymerizable groups in their molecules as described later, photopolymerization initiators or their decomposition products.

[0100] By including the above components (a) to (e) in the negative-type photosensitive composition, the final pixel splitting layer can also contain components (a) to (e).

[0101] The negative-type photosensitive composition for forming the pixel splitting layer preferably contains a compound having two or more radical polymerizable groups in its molecule and a photopolymerization initiator as a photosensitive agent to exhibit negative-type photosensitivity. Examples of compounds having six radical polymerizable groups in their molecule include “KAYARAD” (registered trademark) DPHA, DPCA-20, DPCA-30, DPCA-60, and DPCA-120 (all manufactured by Nippon Kayaku Co., Ltd.).

[0102] Examples of compounds having four radical polymerizable groups in their molecule include "Light Acrylate" (registered trademark) PE-4A (manufactured by Kyoeisha Chemical Co., Ltd.). Examples of compounds having three radical polymerizable groups in their molecule include "Aronics" (registered trademark) M-215 and M-315 (both manufactured by Toagosei Co., Ltd.). Examples of compounds having two radical polymerizable groups in their molecule include "OGSOL" (registered trademark) EA-0200, EA-0250P-LT, GA-2800, and GA-5060P (all manufactured by Osaka Gas Chemical Co., Ltd.), and A-BPEF (manufactured by Shin Nakamura Chemical Industry Co., Ltd.).

[0103] Examples of photopolymerization initiators include oxime ester-based photopolymerization initiators, alkylphenone-based photopolymerization initiators, and acylphosphine oxide-based photopolymerization initiators. Oxime ester-based photopolymerization initiators are preferred because they can improve the deep curing properties of the film with respect to i-rays or mixed rays containing at least i-rays. Examples of oxime ester-based photopolymerization initiators include "ADEKA Cruise" (registered trademark) NCI-831E (manufactured by ADEKA Corporation, hereinafter referred to as "NCI-831E"), "Irgacure" (registered trademark) OXE01, OXE02, OXE03, OXE04 (all manufactured by BASF), and the oxime ester-based photopolymerization initiator described in International Publication No. 2016 / 008384.

[0104] The negative-type photosensitive composition for forming the pixel splitting layer may contain resins other than the aforementioned components (e) and (d). Examples of resins other than the aforementioned components (e) and (d) include (meth)acrylic resin, epoxy (meth)acrylate resin, polyimide resin, polyimide precursor, and polysiloxane resin. From the viewpoint of alkali developability, the weight-average molecular weight (Mw) of these resins is preferably 1,000 or more and 150,000 or less.

[0105] Furthermore, the negative-type photosensitive composition may also contain a solvent. By including a solvent, the viscosity, thixotropy, etc. of the negative-type photosensitive composition can be adjusted, and the uniformity of the film thickness of the coated film can be improved. Preferred solvents include propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA"), 3-methoxybutyl acetate (hereinafter referred to as "MBA"), and methyl ethyl ketone (hereinafter referred to as "MEK").

[0106] One method for preparing a negative photosensitive composition is to prepare a pigment dispersion containing component (a) by wet dispersion treatment, then mix and stir the dispersion containing component (b) with components (d), (e), solvents, and other components as needed, and perform filter filtration as necessary. Component (b) may be prepared by wet dispersion treatment in the presence of component (a).

[0107] For wet dispersion processing, either a wet media disperser or a wet medialess disperser may be used, but the use of a wet media disperser is preferable due to its superior dispersion processing speed and economic advantages. Examples of wet media dispersers include bead mills such as "RevoMill" (registered trademark) (manufactured by Asada Iron Works), "Nano-Getter" (registered trademark) (manufactured by Ashizawa Fine Tech), "DYNO-MILL" (registered trademark) (manufactured by Willy A. Bachofen), "SpikeMill" (registered trademark) (manufactured by Inoue Seisakusho Co., Ltd.), "SandGrinder" (registered trademark) (manufactured by DuPont), "UltraApexMill Advance" (registered trademark) (manufactured by Hiroshima Metal & Machinery Co., Ltd.), and "NEO-AlphaMill" (registered trademark) (manufactured by AIMEX Co., Ltd.).

[0108] For use as a pulverized media in wet media dispersion processing, when component (c) is included in the pixel splitting layer, it is preferable to use ceramic beads with a purity of 90% by weight or more of hafnium oxide (HfO2) or a composite oxide of zirconia and hafnium (ZrO2-HfO2). To further reduce brightness unevenness, the diameter of the pulverized media is preferably 0.03 to 0.5 mmφ, and the higher the sphericity, the better.

[0109] Furthermore, when the organic EL display device of the present invention includes the aforementioned spacer layer, it is preferable that the spacer layer formed in the second layer contains silica particles with a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5, in order to maintain the aperture width of the pixel division layer formed in the first layer and reduce brightness unevenness. It is more preferable that it contains silica particles with a primary particle diameter of 5 to 20 nm, and even more preferable that it contains silica particles with a primary particle diameter of 5 to 15 nm. It is more preferable that it contains silica particles with an aspect ratio of 1.0 to 1.3, and even more preferable that it contains silica particles with an aspect ratio of 1.0 to 1.2.

[0110] In other words, the organic EL display device of the present invention preferably comprises a spacer layer on at least a portion of the surface of the pixel division layer, and the spacer layer preferably contains silica particles having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5.

[0111] A negative-type photosensitive composition can be used as the photosensitive composition for forming the spacer layer. Preferably, by using the same negative-type photosensitive composition as the one used for forming the pixel division layer, the adhesion between the pixel division layer and the spacer layer can be improved, as well as reducing factory wastewater associated with material changes, thereby reducing the environmental burden. [Examples]

[0112] The present invention will be described in detail below with reference to examples and comparative examples thereof, but the embodiments of the present invention are not limited thereto. First, we will explain the evaluation methods used in each example and comparative example.

[0113] <Calculation of optimal exposure> A silver alloy (an alloy consisting of 99.00 wt% silver and 1.00 wt% copper) was deposited over the entire surface of an alkali-free glass substrate measuring 150 mm in length and 150 mm in width by sputtering. Furthermore, an ITO film was deposited over the entire surface by sputtering, resulting in a glass substrate with both a silver alloy film and an ITO film covering the entire surface of the alkali-free glass substrate.

[0114] A negative-type photosensitive composition was applied to the surface of a glass substrate equipped with a silver alloy film / ITO film, on the silver alloy film / ITO film side, using a spin coater, adjusting the rotation speed so that the final thickness of the pixel division layer obtained was 1.5 μm. A pre-baked film was then obtained by pre-baking the coated film at 100°C under atmospheric pressure for 120 seconds using a hot plate. Using a double-sided alignment single-sided exposure apparatus, exposure was performed via a negative-type exposure mask (220 square light-shielding areas, each 30.0 μm long and 30.0 μm wide) with an exposure dose of 20-120 mJ (mJ / cm²). 2The exposure amount was changed in increments of 10 mJ within the range of (i-line equivalent value), and the g, h, and i mixed lines of the ultra-high pressure mercury lamp were pattern-exposed onto the pre-baked film to obtain an exposed film having exposed and unexposed areas in its plane.

[0115] Pattern exposure was performed by bringing a negative-type exposure mask into contact with the surface of the pre-baked film. Next, development was carried out using a paddle method with a 2.38 wt% TMAH aqueous solution using a small photolithography developing device (AD-2000; manufactured by Takizawa Sangyo Co., Ltd.). The paddle method, as defined here, involves showering the surface of the exposure film with the developing solution for 10 seconds, and then leaving the substrate undisturbed until the predetermined development time is reached.

[0116] The development time was defined as the time required to dissolve and remove the unexposed film in the film depth direction multiplied by 1.5. Furthermore, after rinsing with deionized water using a shower method for 30 seconds, the substrate was dried by running it empty at 200 rpm for 30 seconds to obtain a developing film-forming substrate with a patterned developing film. Next, the developing film was heated in a high-temperature inert gas oven (INH-9CD-S; manufactured by Koyo Thermo Systems Co., Ltd.) at 250°C for 1 hour under a nitrogen atmosphere to obtain a cured film. The cured film was observed using an FPD inspection microscope (MX-61L; manufactured by Olympus Corporation), and the minimum exposure (mJ / cm²) was determined when the average value of the aperture widths of 10 apertures in each exposure range was within the range of 30.0 ± 0.1 μm. 2 The value equivalent to the i-line was defined as the optimal exposure amount (exposure sensitivity) for the negative-type photosensitive composition.

[0117] (1) Evaluation of the optical density (OD / μm) of the cured film For the optical density evaluation substrates with a cured film thickness of 1.5 μm obtained in Examples 1-11 and Comparative Examples 1-8, the total optical density (Total OD value) was measured at three in-plane locations from the film surface side using an optical densitometer (X-Rite 361T). The average value was calculated, and this value was divided by 1.5. The result, rounded to the first decimal place, was taken as the OD value per 1.0 μm of cured film thickness (OD / μm). Evaluation was performed based on the criterion that a higher OD / μm indicates a cured film with superior light-shielding properties. The OD value of Tempax without a cured film was measured separately and was 0.00, so the OD value of the optical density evaluation substrate was considered to be the OD value of the cured film. The thickness of the cured film was measured at three points in the plane using a stylus-type film thickness measuring device (Tokyo Seimitsu Co., Ltd.; Surfcom), and the average value was rounded to one decimal place by rounding the second decimal place.

[0118] (2) Evaluation of the aperture width of the pixel splitting layer The pixel-splitting layer-forming substrates and pixel-splitting layer / spacer layer-forming substrates, which had pixel-splitting layers with a thickness of 1.5 μm obtained in Examples 1-12 and Comparative Examples 1-9, were observed using an FPD inspection microscope, and the aperture widths of 10 in-plane openings were measured (Figure 3). Maximum aperture width W 1 (μm) to minimum aperture width W 2 W is the value obtained by subtracting (μm). 3 A smaller (μm) value was considered better, with values ​​below 3.0 being considered passing and values ​​of 3.0 or higher being considered failing.

[0119] (3) Evaluation of brightness uniformity in organic EL display devices The organic EL display devices obtained in Examples 1-12 and Comparative Examples 1-9 were subjected to a 10 mA / cm² test. 2 The pixels were illuminated by DC drive and formed within a 16mm x 16mm area. Twenty pixels located in the center were magnified 50x on a monitor for observation, and the uniformity of brightness within the surface was evaluated based on the following criteria. AA and A-C were considered pass, and D was considered fail. If one or more unlit pixels were observed, the evaluation was set to E regardless of the degree of brightness uniformity, resulting in a fail. AA: No brightness unevenness is observed. A: Very slight unevenness in brightness is visible. B: Slight variations in brightness are visible. C: Brightness unevenness is visible. D: Significant unevenness in brightness is visible. E: One or more non-illuminated pixels are observed.

[0120] The following provides information on the various raw materials used in the examples and comparative examples. Table 1 shows the silica particle content (weight %) in each silica particle dispersion, as well as the cross-sectional analysis results of the pixel division layer corresponding to each silica particle dispersion used in the examples and comparative examples. "MEK-ST-40": A silica particle dispersion containing component (b) (manufactured by Nissan Chemical Industries, Ltd.). The solvent is methyl ethyl ketone. The content of component (b) is 38% by weight per 100% by weight of silica particles. "OSCAL-1421": (b) A silica particle dispersion containing component (manufactured by JGC Catalysts & Chemicals Co., Ltd.). The solvent is isopropyl alcohol. "MEK-ST-L": A silica particle dispersion containing component (b) (manufactured by Nissan Chemical Industries, Ltd.). The solvent is methyl ethyl ketone. "Silica particle dispersion A": A silica particle dispersion containing component (b) (Synthesis Example 3). The solvent is methyl ethyl ketone. "Silica particle dispersion B": A silica particle dispersion containing component (b) (Synthesis Example 4). The solvent is methyl ethyl ketone. "THRULYA": (b) Silica particle dispersion that does not contain component (JGC Catalysts & Chemicals Co., Ltd.). The solvent is isopropyl alcohol. "MEK-ST-ZL": (b) Silica particle dispersion (manufactured by Nissan Chemical Industries, Ltd.) that does not contain component (b). The solvent is methyl ethyl ketone. "ATLAS100": (b) Particles that do not contain component (b) and are neither pigments nor silica particles. "ATLAS" (registered trademark) 100 (manufactured by CABOT). Organic-inorganic composite particles having a primary particle shape in which a silica-containing coating layer is fixed so as to be embedded in a part of the surface of organic polymer particles (silica:polymer = weight ratio 70:30, average primary particle diameter 100 nm, distribution range of primary particle diameter 70-130 nm, solid content 100% by weight)

[0121] [Table 1]

[0122] "S0100": Irgaphor Black (registered trademark) S0100CF. A benzodifuranone-based black pigment consisting of the compound represented by formula (3). Corresponds to component (a). "Bk-CBF1": Surface-coated benzodifuranone-based black pigment Bk-CBF1 disclosed in Coating Example 1 of International Publication No. 2018 / 181311. For every 100 parts by weight of the benzodifuranone-based black pigment consisting of the compound represented by formula (3), the amount of silica coating is 10.0 parts by weight in terms of SiO2, and the amount of alumina coating is 2.0 parts by weight in terms of Al2O3. This corresponds to component (a). "Pigment Dispersant 1": Pigment dispersant 1 (solid content 100% by weight) disclosed in Synthesis Example 2 of Japanese Patent Publication No. 2020 / 70352. A polymer-type dispersant having a linear polyalkyleneamine structure and a polyether polymer chain. "ZCR-1569H": A PGMEA solution of epoxy acrylate resin having a biphenyl skeleton in its main chain. Solids content 70% by weight (manufactured by Nippon Kayaku Co., Ltd.). "TR4020G": A resin having repeating units represented by formula (5). Solids content 100% by weight (manufactured by Asahi Organic Chemicals Co., Ltd.). Corresponds to component (d). "ZAH-106": PGMEA solution of methacrylic polyol resin. Solids content 35% by weight (manufactured by Soken Chemical Co., Ltd.). "DPCA-60": A compound containing six radical polymerizable groups within its molecule. Solid content 100% by weight (manufactured by Nippon Kayaku Co., Ltd.). "GA-5060P": A PGMEA solution of a compound having two radical polymerizable groups in its molecule. Solid content 62% by weight (manufactured by Osaka Gas Chemical Co., Ltd.). "A-BPEF": A PGMEA solution (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) of a compound having one fluorene skeleton, two oxyethylene chains, and two radical polymerizable groups in its molecule. Solid content 50% by weight.

[0123] (Synthesis Example 1: Synthesis of "Polyimide Resin A") Under a stream of dry nitrogen, 31.13 g (0.085 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 1.24 g (0.0050 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, and 2.18 g (0.02 mol) of 3-aminophenol were dissolved in 150.00 g of N-methylpyrrolidone in a three-necked flask.

[0124] A solution was prepared by dissolving 31.02 g of oxydiphthalic anhydride in 50.00 g of N-methylpyrrolidone. This solution was added to the solution in the three-necked flask and stirred at 20°C for 1 hour, then at 50°C for 4 hours. Subsequently, 15 g of xylene was added, and the by-product water was stirred azeotropically with the xylene at 150°C for 5 hours.

[0125] After the reaction was complete, the reaction solution was added to 3 L of deionized water, and the precipitated solid was filtered to obtain the final product. The obtained solid precipitate was washed three times with deionized water and then dried in a vacuum dryer at 80°C for 24 hours to obtain polyimide resin A. Polyimide resin A was in powder form with a solid content of 100% by weight, and its weight-average molecular weight (Mw) was 27,000.

[0126] (Synthesis Example 2: Synthesis of "Epoxy Acrylic Resin Solution B") To a three-necked flask containing 116.88 g of PGMEA, 51.27 g (0.20 mol) of 1,4-cyclohexanedimethanol diglycidyl ether CDMDG (manufactured by Showa Denko K.K.), 28.84 g (0.40 mol) of acrylic acid, 0.05 g of methoquinone as a polymerization inhibitor, and 0.01 g of tetrabutylammonium bromide as a catalyst were added. The mixture was heated to 100°C while stirring, and the reaction was carried out with stirring for 4 hours. After that, heating was stopped and the mixture was cooled to 30°C.

[0127] 175.31 g of PGMEA and 71.07 g (0.16 mol) of 6FDA (manufactured by Daikin Industries, Ltd.), a tetracarboxylic anhydride having two trifluoromethyl groups in its molecule, were added to the solution in the three-necked flask described above. The solution temperature was then raised again to 100°C while stirring, and the mixture was stirred for 4 hours to allow it to react.

[0128] Next, 6.09 g (0.04 mol) of 1,2,3,6-tetrahydrophthalic anhydride was added as a terminal encapsulant, and the mixture was stirred at 90°C for 3 hours to allow it to react. After cooling, a resin solution was obtained containing a resin corresponding to component (e), which has a weight-average molecular weight (Mw) of 3800 and repeating units represented by formula (12).

[0129] This resin solution was diluted with PGMEA to a solid content of 30% by weight, and this was designated as epoxy acrylate resin solution B.

[0130] [ka]

[0131] In equation (12), * represents a bonding site.

[0132] (Synthesis Example 3: Synthesis of "Silica Particle Dispersion A") In a three-necked flask containing 104.50 g of methyl ethyl ketone as a solvent, 142.50 g of MEK-ST-40 as a silica particle dispersion containing component (b) was added, and then 0.01 g of methoquinone was added as a polymerization inhibitor. The mixture was stirred for 10 minutes, and then the temperature of the solution was raised to 50°C.

[0133] Next, a solution was prepared by dissolving 3.00 g of 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface modifier in 50.00 g of methyl ethyl ketone. This solution was added dropwise in equal volumes over 10 minutes, and the mixture was stirred at a temperature of 50°C for 2 hours to allow the dehydration condensation reaction to proceed. After that, the mixture was cooled to 25°C.

[0134] Methyl ethyl ketone was added to the obtained silica particle dispersion so that the solid content was 20% by weight, and the mixture was stirred to obtain silica particle dispersion A containing 20% ​​by weight of silica particles having surface-modifying groups including ethylenically unsaturated double bond groups as component (b).

[0135] (Synthesis Example 4: Synthesis of "Silica Particle Dispersion B") 142.50 g of MEK-ST-40 was added to a three-necked flask containing 104.50 g of methyl ethyl ketone, followed by the addition of 0.01 g of methoquinone. The mixture was stirred for 10 minutes, after which the temperature of the solution was raised to 50°C.

[0136] Next, a solution was prepared by dissolving 3.00 g of 2-methacryloyloxyethyl isocyanate (manufactured by Showa Denko K.K.) as a surface modifier in 50.00 g of methyl ethyl ketone. This solution was added dropwise in equal amounts over 10 minutes, and the mixture was stirred at a temperature of 50°C for 3 hours to allow the urethane reaction to proceed. After that, the mixture was cooled to 25°C.

[0137] Methyl ethyl ketone was added to the obtained silica particle dispersion so that the solid content was 20% by weight, and the mixture was stirred to obtain silica particle dispersion B containing 20% ​​by weight of silica particles having surface-modifying groups including ethylenically unsaturated double bond groups as component (b).

[0138] (Preparation Example 1: Preparation of Pigment Dispersion 1) 770.00 g of PGMEA, the solvent, was mixed with 30.00 g of pigment dispersant 1 for 5 minutes, then 100.00 g of ZCR-1569H was added and mixed for 30 minutes. Furthermore, 100.00 g of S0100 was added as component (a), and the mixture was mixed for 30 minutes to obtain a preliminary mixed solution.

[0139] A pre-agitated liquid was supplied to a vertical bead mill containing a 0.4 mmφ composite oxide grinding media (zirconium oxide:hafnium oxide:yttrium oxide:aluminum oxide = weight ratio 93.3:1.5:4.9:0.3, manufactured by Toray Industries, Inc.) packed into a vessel at a filling rate of 75% by volume. The first wet media dispersion treatment was carried out in a circulating manner at a peripheral speed of 8 m / s for 3 hours.

[0140] Furthermore, the mixture was fed into a vertical bead mill filled with a composite oxide grinding media (zirconium oxide:hafnium oxide:yttrium oxide:aluminum oxide = weight ratio 93.3:1.5:4.9:0.3, manufactured by Toray Industries, Inc.) with a filling rate of 75% by volume. A second wet media dispersion treatment was carried out in a circulating manner at a peripheral speed of 9 m / s for 6 hours, after which it was filtered through a 0.8 μm diameter filter to prepare pigment dispersion 1 with a solid content of 20.00% by weight. The blending weights of each raw material are shown in Table 2.

[0141] [Table 2]

[0142] (Preparation Example 2: Preparation of Pigment Dispersion 2) Pigment dispersion 2 with a solid content of 20.00% by weight was obtained in the same manner as in Preparation Example 1, except that the 0.4 mmφ composite oxide pulverized media was replaced with a 0.3 mmφ silicon nitride pulverized media, the first wet media dispersion treatment was performed at a peripheral speed of 9 m / s for 10 hours, and the second wet media dispersion treatment was omitted. The blending weights of each raw material are shown in Table 2.

[0143] (Preparation Example 3: Preparation of Pigment Dispersion 3) To 770.00 g of PGMEA, the solvent, 30.00 g of pigment dispersant 1 was added and stirred for 5 minutes. Then, 100.00 g of ZCR-1569H was added and stirred for 30 minutes. Furthermore, 40.00 g of CI pigment red 177, 40.00 g of CI pigment blue 15:6, and 20.00 g of CI pigment yellow 24 were added in order, and the mixture was stirred for 30 minutes to obtain a preliminary mixture.

[0144] Subsequently, wet media dispersion treatment and filtration were performed in the same manner as in Preparation Example 1 to prepare pigment dispersion 3 with a solid content of 20.00% by weight. The blending weights of each raw material are shown in Table 2.

[0145] (Preparation Example 4: Preparation of Pigment Dispersion 4) Pigment dispersion 4 was prepared according to the following procedure, following the method of preparation example 1 disclosed in Patent Document 1. As a dispersant, 34.50 g of SOLSPERSE20000 (manufactured by Lubrizol: 100 wt% solids) and 782.00 g of MBA were mixed and stirred for 10 minutes. Then, 103.50 g of S0100 was mixed and stirred for 30 minutes. Wet media dispersion treatment was performed using a horizontal bead mill packed with 0.40 mm zirconia beads to obtain pigment dispersion 4 with a solids content of 15.00 wt%. The blending weights of each raw material are shown in Table 2. The number-average particle size was measured using a zeta potential, particle size, and molecular weight analyzer (Zetasizer Nano ZS, manufactured by Sysmex Corporation).

[0146] (Preparation Example 5: Preparation of Pigment Dispersion 5) Pigment dispersion 5 was prepared according to the method of Preparation Example 9 disclosed in Patent Document 1, using the following procedure. 27.60 g of SOLSPERSE20000, 782.00 g of MBA, and 27.60 g of polyimide resin A were mixed and stirred for 10 minutes. Then, 82.80 g of Bk-CBF1 was mixed and stirred for 30 minutes. Using a horizontal bead mill filled with 0.40 mmφ zirconia beads, a wet media dispersion treatment was performed in the same manner as in Preparation Example 4 to obtain pigment dispersion 5 with a solid content of 15.00 wt%. The blending weights of each raw material are shown in Table 2.

[0147] (Preparation Example 6: Preparation of Organic-Inorganic Composite Particle Dispersion 1) 900.00 g of the solvent PGMEA was mixed with 10.00 g of pigment dispersant 1 and stirred for 30 minutes. Further, 90.00 g of ATLAS100 was added and stirred for another 30 minutes to obtain a preliminary mixture. The preliminary mixture was then fed into a vertical bead mill containing 0.3 mmφ silicon nitride grinding media at a packing density of 75 vol%. A two-pass dispersion treatment was performed at a discharge rate of 300 mL / min and a peripheral speed of 7 m / s to obtain organic-inorganic composite particle dispersion 1 with a solid content of 10.00 wt% and without component (b). The blending weights of each raw material are shown in Table 2.

[0148] (Example 1) Under a yellow light, 0.38 g of OXE03 was added as a photopolymerization initiator to a mixed solvent of 8.50 g of MBA and 16.16 g of PGMEA and stirred for 10 minutes to dissolve. Then, 1.88 g of MEK-ST was added as component (b) and stirred for 10 minutes to dissolve. Next, 4.61 g of ZAH-106, 0.45 g of TR4020G, 0.38 g of DPCA-60, and 0.97 g of GA-5060P were added and stirred for 30 minutes to obtain a clear preparation. 16.69 g of pigment dispersion 1 was mixed into this preparation and stirred for 30 minutes to prepare a negative-type photosensitive composition 1 with a solid content of 15.00% by weight. The blending weights of each raw material are shown in Table 3.

[0149] [Table 3]

[0150] A negative-type photosensitive composition 1 was applied to the surface of a transparent glass substrate, "Tempax" (manufactured by AGC Technoglass Co., Ltd.), using a spin coater with the rotation speed adjusted so that the final cured film thickness was 1.5 μm. The coated film was pre-baked at 100°C for 120 seconds under atmospheric pressure using a hot plate (SCW-636; manufactured by Dainippon Screen Mfg. Co., Ltd.) to obtain a pre-baked film. A double-sided alignment single-sided exposure apparatus was used, and the g, h, i mixed lines of an ultra-high pressure mercury lamp were set as described above. An exposed film was obtained by irradiating the entire surface of the pre-baked film with the optimal exposure amount determined by the method described above. Next, development, rinsing, and drying were performed using the same method as when the optimal exposure amount was calculated to obtain a solid developed film. The developed film was heated at 250°C under air for 1 hour using a high-temperature inert gas oven (INH-9CD-S; manufactured by Koyo Thermo Systems Co., Ltd.) to obtain an optical density evaluation substrate having a solid cured film with a thickness of 1.5 μm, and the optical density (OD / μm) was evaluated using the method described above. The evaluation results are shown in Table 4.

[0151] [Table 4]

[0152] Furthermore, a pixel-splitting layer made of a cured film of negative-type photosensitive composition 1, and an organic EL display device comprising the pixel-splitting layer were fabricated using the following method. Figure 2 shows the manufacturing process of an organic EL display device, including the process of forming a pixel division layer.

[0153] A silver alloy (an alloy consisting of 99.00 wt% silver and 1.00 wt% copper) was deposited over the entire surface of an alkali-free glass substrate 11 measuring 70 mm in length and 70 mm in width by sputtering. Using an alkali-soluble novolac-based positive resist, the substrate was etched by immersion in a silver alloy etching solution SEA-1 at a liquid temperature of 30°C to obtain a patterned silver alloy film 12 with a thickness of 50 nm. Furthermore, an ITO film was deposited over the entire surface by sputtering. Using an alkali-soluble novolac-based positive resist, the ITO film was immersed in a 5 wt% oxalic acid aqueous solution at a liquid temperature of 50°C for 5 minutes, shower-washed with deionized water for 2 minutes, and then dried with an air blower to obtain a patterned ITO film 13 with a thickness of 10 nm. Through these steps, a first electrode-forming substrate was obtained on the surface of the alkali-free glass substrate, comprising a first electrode consisting of a laminated pattern of silver alloy film / ITO film.

[0154] Negative-type photosensitive composition 1 was applied to the surface of the first electrode formation substrate using a spin coater, adjusting the rotation speed so that the final pixel division layer thickness was 1.5 μm, to obtain a coated film. Furthermore, the coated film was pre-baked for 120 seconds at 100°C under atmospheric pressure using a hot plate to obtain a pre-baked film. Using a double-sided alignment single-sided exposure apparatus, the pre-baked film was pattern-exposed using the optimal exposure amount determined by the method described above, via a negative-type exposure mask (220 square light-shielding sections with dimensions of 30.0 μm vertically and 30.0 μm horizontally arranged) to obtain an exposed film. The pattern exposure was performed with the negative-type exposure mask in contact with the surface of the pre-baked film. Next, development, rinsing, and drying were performed using the same method as when the optimal exposure amount was calculated to obtain a patterned developed film. The developing film was heated at 250°C for 1 hour under a nitrogen atmosphere using a high-temperature inert gas oven to obtain a pixel-splitting layer forming substrate having a pixel-splitting layer 14 with a thickness of 1.5 μm and 220 openings in a 30 mm x 30 mm area in the center of the first electrode forming substrate. The results of evaluating the opening width using the method described above are shown in Table 4.

[0155] Next, an organic EL layer 15 including the light-emitting layer is formed in the opening of the pixel division layer 14 by vacuum deposition, using a vacuum degree of 1 × 10⁻¹⁰. -3Under deposition conditions below Pa, the pixel-splitting layer-forming substrate was rotated relative to the deposition source. First, a 10 nm thick layer of compound (HT-1) represented by formula (13) was deposited as a hole injection layer, and a 50 nm thick layer of compound (HT-2) represented by formula (14) was deposited as a hole transport layer. Next, a 40 nm thick layer of compound (GH-1) represented by formula (15) was deposited as a host material, and a 40 nm thick layer of compound (GD-1) represented by formula (16) was deposited as a dopant material. Subsequently, a 40 nm thick layer of compound (ET-1) represented by formula (17) and compound (LiQ) represented by formula (18) was deposited as electron transport materials in a volume ratio of 1:1.

[0156] [ka]

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] Next, after depositing a compound (LiQ) at a thickness of 2 nm, a silver / magnesium alloy (volume ratio 10:1) was deposited to a thickness of 150 nm to form the second electrode 16. Then, under a low humidity / nitrogen atmosphere, a cap-shaped glass plate was sealed by bonding it using an epoxy resin adhesive to obtain an organic EL display device with an array of green light-emitting pixels. The layers constituting the organic EL layer 15 are very thin compared to the aforementioned pixel division layer, and high measurement accuracy cannot be obtained with a stylus-type film thickness measuring device. Therefore, each layer was measured using a quartz oscillator type film thickness monitor suitable for thin films of less than 100 nm, and the film thickness was obtained by rounding the average value of three points in the plane to the first decimal place. The brightness uniformity of the fabricated organic EL display device was evaluated using the method described above. After evaluating the brightness uniformity, the organic EL display device was disassembled, and the content of component (c) in the pixel division layer was quantified by ICP emission spectrometry (detection limit of hafnium atoms: 0.2 ppm by weight), and the result was 3.0 ppm by weight. Furthermore, analysis using TEM-EDX confirmed that the pixel separation layer contained component (b). In addition to the primary particle diameter and aspect ratio of component (b), the average primary particle diameter (nm) and average aspect ratio of the silica particles were measured. The results of these evaluations are shown in Table 4.

[0163] (Examples 2-3) Negative photosensitive compositions 2 and 3 were prepared using OSCAL-1421 or MEK-ST-L instead of MEK-ST-40, in the formulations shown in Table 3. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1, and the content of component (c) in the pixel division layer was quantified. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer contained component (b). In addition to the primary particle diameter and aspect ratio of component (b), the average primary particle diameter (nm) and average aspect ratio of silica particles were measured. The evaluation results are shown in Table 4.

[0164] (Examples 4-7) Negative-type photosensitive compositions 4 to 7 were prepared using pigment dispersions 1 to 3 and epoxy acrylate resin solution B in the proportions shown in Table 5. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1, and the content of component (c) in the pixel division layer was quantified. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer contained component (b). In addition to the primary particle diameter and aspect ratio of component (b), the average primary particle diameter (nm) and average aspect ratio of silica particles were measured. The evaluation results are shown in Table 6.

[0165] [Table 5]

[0166] [Table 6]

[0167] (Comparative Example 1) Under a yellow light, 0.57 g of NCI-831 was added to a mixed solvent of 6.38 g of MBA and 23.20 g of PGMEA and stirred for 10 minutes to dissolve. To this, 3.08 g of polyimide resin A, 1.18 g of KAYARAD DPHA, and 0.95 g of A-BPEF were added and stirred to obtain a formulation. This formulation was mixed with 14.65 g of pigment dispersion 4 and stirred for 30 minutes to prepare a negative-type photosensitive composition 8 with a solid content of 15.00 wt%. The blending weights of each raw material are shown in Table 7. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1. In analysis by ICP emission spectrometry, component (c) was not detected in the pixel division layer (detection limit less than 0.2 wt ppm). Furthermore, analysis by TEM-EDX confirmed that the pixel division layer did not contain component (b). The evaluation results are shown in Table 8.

[0168] [Table 7]

[0169] [Table 8]

[0170] (Comparative Example 2) Negative-type photosensitive compositions 9 were prepared using pigment dispersion 5 instead of pigment dispersion 4, in the proportions shown in Table 7. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1. Component (c) was not detected in the pixel division layer by ICP emission spectrometry. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer did not contain component (b). The evaluation results are shown in Table 8.

[0171] (Comparative Examples 3-4) Negative photosensitive compositions 10 to 11 were prepared using pigment dispersion 2 instead of pigment dispersion 1, and THRULYA or MEK-ST-ZL instead of MEK-ST-40, in the formulations shown in Table 7. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1. Component (c) was not detected in the pixel division layer by ICP emission spectrometry. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer did not contain component (b). The measurement results of the average primary particle diameter (nm) and average aspect ratio of the silica particles are shown in Table 8. The evaluation results are shown in Table 8.

[0172] (Example 8) Instead of MEK-ST-40, a negative-type photosensitive composition 12 was prepared using silica particle dispersion A in the proportions shown in Table 9, and the optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 10. In the analysis by ICP emission spectrometry, the content of component (c) in the pixel division layer was 3.0 ppm by weight. 29 Si nuclear magnetic resonance method, 1 Analysis using H nuclear magnetic resonance and TEM-EDX revealed that the pixel splitting layer obtained from the negative-type photosensitive composition 12 is R in formula (19). 16 is a methyl group, R17 The pixel-resolved layer contained component (b), which has a structure in which the propylene group is present, j and k are 1, m is 3, and n is 0 as a reaction residue. In addition, TEM-EDX analysis was performed to measure the primary particle diameter and aspect ratio of component (b), as well as the average primary particle diameter (nm) and average aspect ratio of the silica particles. The results of these evaluations are shown in Table 10.

[0173] [Table 9]

[0174] [Table 10]

[0175] (Example 9) Instead of MEK-ST-40, a negative-type photosensitive composition 13 was prepared using silica particle dispersion B in the proportions shown in Table 9, and the optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 10. In the analysis by ICP emission spectrometry, the content of component (c) in the pixel division layer was 3.0 ppm by weight. 29 Si nuclear magnetic resonance method, 1 Analysis using H nuclear magnetic resonance and TEM-EDX revealed that the pixel splitting layer obtained from the negative-type photosensitive composition 13 has a structure represented by formula (20), where R 19 is a methyl group, R 20 The pixel-resolved layer contained component (b), which has an oxyethylene group and a structure with r = 1 as a reaction residue. In addition, TEM-EDX analysis was performed to measure the primary particle diameter and aspect ratio of component (b), as well as the average primary particle diameter (nm) and average aspect ratio of silica particles. The results of this evaluation are shown in Table 10.

[0176] (Comparative Examples 5-6) Negative photosensitive compositions 14-15 were prepared using pigment dispersion 2 instead of pigment dispersion 1, and MEK-ST-ZL instead of MEK-ST-40, in the formulations shown in Table 9. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 10. In the analysis by ICP emission spectrometry, component (c) was not detected in the pixel division layer. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer did not contain component (b), and the average primary particle diameter (nm) and average aspect ratio of the silica particles were measured. The results of these evaluations are shown in Table 10.

[0177] (Examples 10-11) Negative photosensitive compositions 16-17 were prepared by varying the content of component (b) using the formulations shown in Table 11. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1, and the content of component (c) in the pixel division layer was quantified. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer contained component (b). In addition to the primary particle diameter and aspect ratio of component (b), the average primary particle diameter (nm) and average aspect ratio of silica particles were measured. The evaluation results are shown in Table 12.

[0178] [Table 11]

[0179] [Table 12]

[0180] (Comparative Examples 7-8) Negative-type photosensitive compositions 18-19 were prepared in the same manner as in Example 1, except that pigment dispersion 2 was used instead of pigment dispersion 1 and organic-inorganic composite particle dispersion 1 was used instead of MEK-ST-40, in the formulation amounts shown in Table 11. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness uniformity of the organic EL display device were evaluated in the same manner as in Example 1, and the content of component (c) in the pixel division layer was quantified. Furthermore, analysis by TEM-EDX confirmed that the pixel division layer did not contain component (b). The evaluation results are shown in Table 12.

[0181] (Example 12) An additional pixel-splitting layer-forming substrate comprising a pixel-splitting layer 17 was fabricated using the same method as in Example 1, with the negative-type photosensitive composition 1.

[0182] The negative-type photosensitive composition 1 was coated onto the entire surface of the pixel-divided layer 17 and the openings 18 of the pixel-divided layer 17 using a spin coater, adjusting the rotation speed so that the final thickness of the pixel-divided layer obtained was 1.8 μm, thereby obtaining a coated film. Furthermore, the coated film was pre-baked for 120 seconds at 100°C under atmospheric pressure using a hot plate to obtain a pre-baked film. Using a double-sided alignment single-sided exposure apparatus, the pre-baked film was pattern-exposed through a negative-type exposure mask (with 50 square openings of 45.0 μm in length and 45.0 μm in width) so that the developing film described later would be 45.0 μm in length and 45.0 μm in width, thereby obtaining an exposed film. Next, the film was developed using a paddle method with a 2.38 wt% TMAH aqueous solution using a small photolithography developing apparatus (AD-2000; manufactured by Takizawa Sangyo Co., Ltd.). The development time was defined as the time it takes for the unexposed portion of the film in the opening 18 of the pixel division layer 17 to dissolve and be removed in the film depth direction multiplied by 1.5. Furthermore, after rinsing with deionized water in a shower manner for 30 seconds, the substrate was dried by running it empty at 200 rpm for 30 seconds to obtain a developing film-forming substrate having a patterned developing film. Next, the developing film was heated in a high-temperature inert gas oven at 250°C under a nitrogen atmosphere for 1 hour to obtain a pixel division layer / spacer layer-forming substrate (Figure 4) having a 1.5 μm thick pixel division layer 17 with a 1.8 μm thick spacer layer 19 on a part of its surface. The results of evaluating the opening width of the pixel division layer using the method described above are shown in Table 13.

[0183] [Table 13]

[0184] Next, an organic EL layer 15 and a second electrode 16 were formed in the same manner as in Example 1, except that a pixel-splitting layer / spacer layer forming substrate was used instead of a pixel-splitting layer forming substrate equipped with a pixel-splitting layer 14. An organic EL display device was then fabricated, the brightness uniformity was evaluated, and the content of component (c) in the pixel-splitting layer was quantified. Furthermore, analysis by TEM-EDX confirmed that the spacer layer contained silica particles with a primary particle diameter of 12 nm and an aspect ratio of 1.1. The evaluation results are shown in Table 13. The primary particle diameter and aspect ratio of the silica particles in the spacer layer were measured using the same method as the measurement method for component (b) in the pixel-splitting layer in Example 1.

[0185] (Comparative Example 9) An additional pixel-splitting layer-forming substrate comprising a pixel-splitting layer 17 was fabricated using the same method as in Example 1, except that negative-type photosensitive composition 8 was used. Next, a pixel-splitting layer / spacer layer-forming substrate and an organic EL display device were fabricated using the same method as in Example 12, except that negative-type photosensitive composition 8 was used instead of negative-type photosensitive composition 1. Brightness uniformity was evaluated, and the content of component (c) in the pixel-splitting layer was quantified. Furthermore, analysis by TEM-EDX confirmed that the spacer layer did not contain silica particles. The evaluation results are shown in Table 13.

[0186] From the above results, the organic EL display devices equipped with a pixel-splitting layer containing component (b) in Examples 1 to 11 were superior to the organic EL display devices equipped with a pixel-splitting layer not containing component (b) in Comparative Examples 1 to 8 in that the difference W3 between the maximum aperture width W1 and the minimum aperture width W2 at the aperture was smaller and the brightness uniformity was less. In particular, in addition to Example 6 which contained component (e), Examples 8 to 9 which contained component (b) having a structure represented by formula (19) or a structure represented by formula (20) as a reaction residue showed particularly good brightness uniformity. On the other hand, in Comparative Examples 4 to 6 which contained only silica particles that do not correspond to component (b), no improvement in brightness uniformity was observed even when the silica particle content or the content of compounds with two or more radical polymerizable groups in the molecule was increased. Furthermore, in Comparative Examples 7 to 8 which contained organic inorganic composite particles that do not correspond to component (b) even though they contained silica, no effect of reducing the difference W3 was observed, and the adverse effect of non-illuminated pixels occurred, so the effects of the present invention were not obtained. On the other hand, in Example 12, which includes a spacer layer, the inclusion of silica particles with a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5 allowed the average value of the aperture width and the difference W3 of the pixel division layer in Example 1 to be maintained, demonstrating superiority compared to Comparative Example 9. From the above, it has been confirmed that the organic EL display device of the present invention is useful. [Explanation of symbols]

[0187] 1: TFT 2: Wiring 3: TFT insulating layer 4: Flattening layer 5:First electrode 6: Circuit board 7: Contact Hole 8: Pixel splitting layer 9: Emitting pixels 10:Second electrode 11: Alkali-free glass substrate 12: Silver alloy film 13: ITO film 14: Pixel division layer 15: Organic EL layer 16:Second electrode 17: Pixel division layer 18: Opening 19: Spacer layer 20: Alkali-free glass substrate 21: Silver alloy film 22: ITO film

Claims

1. An organic EL display device comprising a substrate, a first electrode, a pixel splitting layer, a light-emitting pixel, and a second electrode, wherein the pixel splitting layer contains (a) an organic black pigment and / or a mixed organic black pigment, (b) silica particles having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5, and (d) a phenolic resin, and the phenolic resin has the structure of the following formula (5). 【Chemistry 1】 (In formula (5), R 11 represents a methylene group or a CH-Ar group. Ar represents a phenyl group or a substituted phenyl group. * represents a bonding site.)

2. The organic EL display device according to claim 1, wherein the average primary particle diameter of the silica particles contained in the pixel splitting layer is 5 to 30 nm, and the average aspect ratio (major axis / minor axis) is 1.0 to 1.

3.

3. The content of component (b) relative to 100 parts by weight of component (a) is SiO ２ The organic EL display device according to claim 1 or 2, which is 20 to 70 parts by weight in conversion.

4. The organic EL display device according to any one of claims 1 to 3, wherein the component (b) contains silica particles having sodium atoms.

5. Furthermore, the organic EL display device according to any one of claims 1 to 4, wherein at least a portion of the surface of the pixel division layer is provided with a spacer layer, and the spacer layer contains silica particles having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.

5.

6. The organic EL display device according to any one of claims 1 to 5, wherein the component (a) contains an organic black pigment, and the organic black pigment contains a compound represented by formula (1) or formula (2) and / or an isomer thereof. 【Chemistry 2】 【Transformation 3】 (In equations (1) and (2), R １ ~R １０ Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

7. The organic EL display device according to any one of claims 1 to 6, wherein the component (b) contains silica particles having a reaction residue of a surface modification group containing an ethylenically unsaturated double bond group on the particle surface, and the reaction residue of the surface modification group containing an ethylenically unsaturated double bond group has a structure represented by formula (19) and / or a structure represented by formula (20). 【Chemistry 4】 (In formula (19), R １６ R represents a hydrogen atom or a methyl group. １７ * represents a divalent hydrocarbon group with 1 to 7 carbon atoms. j and k are integers, each independently representing either 0 or 1. However, if j is 1, then k is 1. １ This represents the bonding site with a carbon atom. * ２ R represents the bonding site between silicon atoms and oxygen atoms on the particle surface of silica particles. １８ represents an alkyl group with 1 to 3 carbon atoms. m and n are integers, where m represents 1 to 3 and n represents 0 to 2. (However, m + n = 3.) 【Transformation 5】 (In formula (20), R １９ represents a hydrogen atom or a methyl group. R ２０ represents an oxyalkylene group having 1 to 3 carbon atoms. r is an integer and represents 1 to 4. * ３ represents a bonding site with a carbon atom. * ４ (This represents the bonding site between silicon atoms and oxygen atoms on the surface of silica particles.)

8. The organic EL display device according to any one of claims 1 to 7, wherein the pixel splitting layer contains (c) 1 to 50 ppm by weight of hafnium atoms.

9. The organic EL display device according to any one of claims 1 to 8, wherein the pixel splitting layer contains a resin having repeating units having an acryloyl group or a methacryloyl group and a trifluoromethyl group.

10. The organic EL display device according to claim 9, wherein the repeating unit having an acryloyl group or a methacryloyl group and a trifluoromethyl group has a structure represented by formula (7). 【Transformation 6】 (In formula (7), R 13 represents a hydrogen atom or a methyl group. * represents a bonding site.)

11. The organic EL display device according to any one of claims 1 to 10, wherein the optical density per 1 μm of film thickness of the pixel splitting layer is 0.7 to 1.

2.

12. An organic EL display device comprising a substrate, a first electrode, a pixel splitting layer, an emissive pixel, and a second electrode, wherein the pixel splitting layer contains (a) an organic black pigment and / or a mixed organic black pigment, (b) silica particles having a primary particle diameter of 5 to 30 nm and an aspect ratio (major axis / minor axis) of 1.0 to 1.5, and (e) a resin having repeating units having an acryloyl group or a methacryloyl group and a trifluoromethyl group, and the repeating units having an acryloyl group or a methacryloyl group and a trifluoromethyl group have a structure represented by formula (7). 【Transformation 7】 (In formula (7), R 13 represents a hydrogen atom or a methyl group. * represents a bonding site.)

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