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

Organic EL display device

[0001] The present invention relates to an organic electroluminescence display device.

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

[0003] In recent years, in order to improve the visibility and contrast of organic EL display devices, a technique of blackening pixel division layers to impart light-blocking properties has attracted attention in order to suppress color mixing due to light leakage into adjacent light-emitting pixels and reflection of external light such as sunlight. Patent Document 1 discloses, for example, a negative-type photosensitive composition containing an organic black pigment, a polyimide resin, and a fluorene-based acrylate compound as a material for forming a black pixel division layer. Patent Document 1 states that a pixel division layer having both high light-blocking properties and a low taper angle can be formed.

[0004] International Publication No. 2018 / 181311

[0005] However, when an organic EL display device having a black pixel dividing layer is produced using the negative photosensitive composition disclosed in Patent Document 1, there is a problem in that the brightness varies greatly.

[0006] The present invention provides an organic EL display device comprising a substrate, a first electrode, a pixel division layer, light-emitting pixels, 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.

[0007] According to the present invention, an organic EL display device with little unevenness in brightness is provided.

[0008] 1 is a cross-sectional view of a TFT substrate in an organic EL display device that is a specific example of an embodiment of the present invention. 2 is a diagram illustrating a manufacturing process of an organic EL display device, including a step of forming a pixel dividing layer, in all examples and comparative examples. 3 is a diagram illustrating a maximum opening width W of an opening in a substrate for evaluating an opening width in all examples and comparative examples. １ and the minimum opening width W ２ 13 is a schematic diagram showing a pixel dividing layer / spacer layer-forming substrate in Example 12, as viewed from the film surface side and as viewed from a cross section.

[0009] The present invention will be described in detail below. A numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. The pixel division layer refers to a pixel division layer provided in an organic EL display device and does not include the black matrix of a liquid crystal display device. Visible light refers to light in the wavelength range of 380 nm or more and less than 780 nm, and near ultraviolet refers to light in the wavelength range of 200 nm or more and less than 380 nm. Light-shielding refers to the function of reducing the intensity of transmitted light compared to the intensity of light incident perpendicularly to the cured film, and light-shielding properties refer to the degree to which visible light is blocked. The photosensitive composition refers to a photosensitive composition that is photosensitive to near ultraviolet light and is alkali-developable. The weight-average molecular weight (Mw) is a value obtained by analyzing a composition by gel permeation chromatography using tetrahydrofuran as a carrier and converting it using a calibration curve based on standard polystyrene.

[0010] The "C.I." used in the names of some colorants is an abbreviation for Color Index Generic Name, which is based on the Color Index published by the Society of Dyers and Colourists. For colorants registered in the Color Index, the Color Index Generic Name indicates the chemical structure and crystalline form of the pigment or dye. Carbon blacks classified as C.I. Pigment Black 7, for example, are classified as inorganic black pigments. The solid content refers to the proportion (by weight) of components in the photosensitive composition excluding solvents and water.

[0011] As a result of investigating the above-mentioned problem, the inventors found that, typically, light-emitting pixels are composed of at least three colors: blue, red, and green. For green pixels, which have high luminous efficiency and are designed with the shortest minor axis of their apertures, in-plane variations in pixel size are particularly likely to be visually perceived by users as luminance unevenness. Here, luminous efficiency refers to the strength at which the human eye perceives brightness for each wavelength of light. Furthermore, because the stacked structure of the light-emitting element determines the size of the light-emitting pixels by the aperture width of the pixel divider layer, large in-plane variations in aperture width were considered to be the cause of the luminance unevenness.

[0012] In view of the above, the present inventors have conducted extensive research and found that the following configuration provides an especially remarkable effect in solving the above-mentioned problems. That is, the present invention is an organic EL display device including a substrate, a first electrode, a pixel division layer, light-emitting pixels, 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.

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

[0014] Bottom-gate or top-gate thin film transistors 1 (hereinafter abbreviated as TFT1) are arranged in a matrix on the surface of a substrate 6, and a TFT insulating layer 3 is formed to cover 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 contact holes 7 are formed in the planarization layer 4 for connecting first electrodes 5 to the wiring 2. First electrodes 5 are patterned on the surface of the planarization layer 4 and connected to the wiring 2. A pixel division layer 8 is formed surrounding the periphery of the pattern of the first electrodes 5. Openings are formed in the pixel division layer 8, and light-emitting pixels 9 containing an organic EL light-emitting material are formed in the openings. A second electrode 10 is formed to cover the pixel division layer 8 and the light-emitting pixels 9. After sealing the TFT substrate having the above layered structure under vacuum, a voltage is applied to the light-emitting pixel portions, causing the display to emit light as an organic EL display device.

[0015] The shape of the openings in the pixel division layer 8 is not particularly limited and may be square, rectangular, or elliptical. The opening width of the openings may be appropriately determined depending on the size of the light-emitting pixels 9 described below, and may, for example, have a minor axis of 10 to 50 μm. The optical density per μm of film thickness of the pixel division layer provided in the organic EL display device of the present invention is preferably 0.5 or more, more preferably 0.7 or more, in order to suppress external light reflection and enhance the value of the display device. In order to suppress brightness unevenness, it is preferably 1.5 or less, more preferably 1.2 or less. Here, the optical density per μm of film thickness refers to the value obtained by measuring the incident light intensity and the transmitted light intensity using an optical densitometer (X-Rite 361T, manufactured by X-Rite Corporation), dividing the value calculated using the following formula by the film thickness, and rounding the value to one decimal place. A higher optical density indicates better light-blocking properties.

[0016] Optical density = log １０ (I ０ / I) I ０ : Incident light intensity I: Transmitted light intensity.

[0017] The pixel division layer 8 is usually formed to a film thickness of 1 to 4 μm, and 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 formability of the second electrode 10 and prevent non-illumination of the light-emitting pixel. The taper angle is preferably 15° or more, and more preferably 20° or more, in order to prevent a decrease in the light-blocking property of the edge of the pixel division layer.

[0018] In order to reduce unevenness in brightness, it is desirable to form the pixel division layer by photolithography using an alkali-developable photosensitive composition. The photosensitive composition may be a negative-type photosensitive composition or a positive-type photosensitive composition, but a negative-type photosensitive composition is preferred because it has high exposure sensitivity, is excellent in terms of the ease of forming a pixel division layer with high light-shielding properties, and is also excellent in terms of productivity. That is, the pixel division layer provided in the organic EL display device of the present invention is preferably a cured film formed from a negative-type photosensitive composition.

[0019] A method for forming a pixel dividing layer using a negative photosensitive composition preferably includes a coating step of applying a negative photosensitive composition to obtain a coating film, an exposure step of exposing the composition to actinic radiation through a negative exposure mask in a pattern to obtain an exposed film having exposed and unexposed parts in its surface, a development step of developing the composition using an alkaline developer to remove the unexposed parts of the film to obtain a developed film, and a curing step of thermally curing the composition by heating to obtain a cured film.

[0020] As the coating device used in the coating step, a spin coater or slit coater is preferably used because of 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 the exposure device used in the exposure process include a stepper, a mirror projection mask aligner (MPA), and a parallel light mask aligner (PLA).The active actinic rays irradiated during exposure include the j-line (wavelength 313 nm), the i-line (wavelength 365 nm), the h-line (wavelength 405 nm) or the g-line (wavelength 436 nm) of a mercury lamp, and more preferably the i-line or a mixed line containing at least the i-line.Examples of negative exposure masks include a mask in which a thin film having shielding properties made of a metal such as chromium is formed in a pattern on one side of a substrate having transparency at the exposure wavelength, such as glass, quartz, or film, and only the openings are allowed to transmit active actinic rays for pattern exposure, thereby obtaining an exposed film having exposed areas and unexposed areas within the surface.

[0022] The exposed area here refers to an area that has been exposed to light, and the unexposed area refers to an area that has not been exposed to light.

[0023] Examples of the development method used in the development step include showering, dipping, and puddling, and examples include a method in which the exposed film is immersed for 10 seconds to 3 minutes. The puddling method is preferred to improve the in-plane uniformity of the opening width of the openings. The alkaline developer is preferably a 1.0 to 2.5 wt % aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH), and a commercially available product is, for example, 2.38 wt % TMAH (manufactured by Tama Chemicals Co., Ltd.). After the development step, a washing treatment using a shower of deionized water and / or a water-removing treatment using an air jet may be performed.

[0024] In the curing step, the developed film is thermally cured by heating while simultaneously volatilizing moisture and the like to obtain a cured film. Examples of heating devices include a hot air oven and an IR oven. The heating temperature is preferably 200 to 350°C under atmospheric pressure, more preferably 220 to 280°C. Since 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 step by setting the heating temperature range to 350°C or less. 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 section of the organic EL display device with a formation area of ​​30% or less of the formation area of ​​the pixel division layer. The spacer layer reduces the contact area between the pixel division layer and the vapor deposition mask when forming the light-emitting pixels 9 described below, i.e., provides a spacer effect, suppresses defects in the organic EL elements, improves yield, and increases productivity of the organic EL display device. The spacer layer is preferably formed by photolithography, and for example, the same method as the method for forming the pixel division layer described above can be used. The thickness of the spacer layer is preferably 0.5 to 2.0 μm.

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

[0027] Examples of methods for forming patterns of light-emitting pixels include mask vapor deposition. Mask vapor deposition is a method of depositing and patterning an organic compound using a vapor deposition mask. Specifically, a method of depositing a vapor deposition mask with openings of a desired pattern on a substrate is exemplified. To obtain a highly accurate vapor deposition pattern, it is important to closely adhere a highly flat vapor deposition mask to the substrate. Generally, techniques such as applying tension to the vapor deposition mask or adhering the vapor deposition mask to the substrate using a magnet placed on the back of the substrate can be used. Examples of methods for manufacturing vapor 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 preferred because of its excellent processing accuracy.

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

[0029] Next, only the ITO film in the areas where the resist pattern is not formed is removed using an etching solution at a temperature of 20 to 60°C, and then the resist pattern is removed using a resist stripper at a temperature of 20 to 60°C. If necessary, heat treatment is performed to achieve the desired crystallinity. The term "ITO" as used herein encompasses so-called amorphous ITO. Positive resist materials for etching can be positive photosensitive compositions containing alkali-soluble novolac resins. Etching solutions can be aqueous solutions containing nitric acid and hydrochloric acid, or aqueous solutions of oxalic acid. Commercially available products include ITO-101N (manufactured by Kanto Chemical Co., Ltd.), "Sclean" (registered trademark) IS-2, and "Sclean" IS-3 (all manufactured by Sasaki Chemical Co., Ltd.).

[0030] An organic amine aqueous solution can be used as the resist stripper, and examples of commercially available products include "Anlast" (registered trademark) M6, M6B, TN-1-5, and M71-2 (all manufactured by Sanwa Pure Chemical Research Institute). When the organic EL display device of the present invention is a top-emission 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 may 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, when the organic EL display device of the present invention is a bottom-emission organic EL display device, a layer made of aluminum is preferably used because of its excellent light reflectivity. When the organic EL display device is a top-emission organic EL display device, a layer made of a silver alloy consisting of silver / magnesium is preferably used because of its excellent light transmittance. The second electrode can be obtained by forming a film over the entire surface by sputtering.

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

[0033] If a hard plate-like base material such as glass is used for the substrate 6, a rigid organic EL display device that cannot be bent can be produced. As the glass, alkali-free glass containing less than 0.5% alkali metal elements and primarily composed of silicon can be suitably used. Among these, glass with a small thermal expansion coefficient and excellent dimensional stability in high-temperature processes at 250°C or higher is preferred, such as OA-10G and OA-11 (both manufactured by Nippon Electric Glass Co., Ltd.) and AN-100 (manufactured by Asahi Glass Co., Ltd.), and the thickness thereof is typically 0.1 to 0.5 mm from the viewpoint of physical durability.

[0034] On the other hand, using a flexible substrate for the substrate 6 allows for a flexible organic EL display device that can be bent. A substrate made of polyimide resin, which has high flexibility and excellent mechanical strength, is suitable for use as a flexible substrate. One method for producing such a substrate is to apply a solution containing polyamic acid to the surface of a temporary support, then heat the polyamic acid to imidize it and convert it into a polyimide resin, and then peel off the temporary support using a laser or other device. The polyamic acid used in this case can be synthesized by reacting a tetracarboxylic dianhydride with a diamine compound in an amide solvent such as N-methyl-2-pyrrolidone. Among these, polyamic acid having residues of an aromatic tetracarboxylic dianhydride and an aromatic diamine compound is preferred due to its low coefficient of linear 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 typically 10 to 40 μm, allowing for a thinner substrate 6 compared to the case where the 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-color organic black pigment (hereinafter, sometimes referred to as component (a)). Component (a) has the effect of imparting light-blocking 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 those disclosed in International Publication No. 2009 / 010521. Commercially available benzodifuranone-based black pigments made of a compound represented by formula (3) described below include Irgaphor Black (registered trademark) S0100CF and Experimental Black 582 (both manufactured by BASF).

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

[0039] Examples of azomethine black pigments include the pigments disclosed in U.S. Patent Application Publication No. 2002-121228. A commercially available product that can be used is Chromofine Black A1103 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.).

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

[0041] Examples of organic yellow pigments include C.I. Pigment Yellow 24, 120, 138, 139, 151, 175, 180, 185, 181, 192, 193, and 194. Examples of organic orange pigments include C.I. Pigment Orange 13, 36, 43, 60, 61, 62, 64, 71, and 72. Examples of organic red pigments include C.I. Pigment Red 122, 123, 149, 178, 177, 179, 180, 189, 190, 202, 209, 254, 255, and 264. Examples of organic blue pigments include C.I. Examples of organic purple pigments include C.I. 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 C.I. Pigment Violet 19, 23, 29, 32, and 37.

[0042] Of the components corresponding to the above component (a), in order to reduce unevenness in brightness, it is preferable that the component (a) contained in the pixel division layer provided in 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 an isomer thereof. It is more preferable that the component (a) contained in the pixel division layer contains a compound represented by formula (3) or an isomer thereof. The compounds represented by formulas (1) to (3) can be synthesized by reacting 2,5-dihydroxy-1,4-benzenediacetic acid with isatin or a derivative thereof in the presence of an acid catalyst, and then converted into a pigment.

[0043]

[0044]

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

[0046]

[0047] In order to further suppress unevenness in brightness, the component corresponding to component (a) may be subjected to a micronization treatment by a known method such as a solvent salt milling method or an acid paste method. When micronizing a benzodifuranone black pigment, the coexistence of the compound represented by formula (4) or a salt thereof and adsorption onto the pigment surface may facilitate suppression of unevenness in brightness.

[0048]

[0049] In formula (4), n and m each independently represent an integer of 0 to 2, provided that n + m ≥ 1 is satisfied. Furthermore, when component (a) contains a benzodifuranone-based black pigment, the pigment surface preferably has a coating layer containing silica in order to improve developability and suppress development residues in the openings. The silica contained in the coating layer here is not component (b) but is considered to be part of component (a).

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

[0051] The pixel dividing layer of the organic EL display device of the present invention contains (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 (hereinafter, sometimes referred to as component (b)). The term "primary particle diameter" as used herein refers to the major axis of the particle, and silica particles having a primary particle diameter of 5 to 30 nm refer to particles having a primary particle diameter within the range of 5 to 30 nm. The term "aspect ratio (major axis / minor axis)" as used herein refers to the value obtained by dividing the major axis by the minor axis of the primary silica particles, rounded to one decimal place, and silica particles having an aspect ratio of 1.0 to 1.5 refer to particles having an aspect ratio within the range of 1.0 to 1.5. Component (b) has the effect of increasing the uniformity of the opening width of the openings and reducing brightness unevenness.

[0052] The silica particles referred to here are SiO ２ The term "silica particles" refers to particles with a pure content of 90% by weight or more, 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 of the hydrated silicic acid is not particularly limited, and particles made of orthosilicic acid, metasilicic acid, and / or metadisilicic acid also fall under the category of silica particles. The weight excluding water refers to the weight of the particles minus the weight of the water in the particles.

[0053] However, in the core-shell type composite particles, the core is SiO ２ The surface treatment agent and coating layer applied as a shell to at least a part of the surface of particles that do not contain a component, such as particles made of an organic polymer, organic pigments, or inorganic pigments, are SiO ２ Even if it contains SiO ２ On the other hand, regardless of the purity of the SiO2 particles in the core, these particles alone are not considered to be silica particles. ２ of the weight of the mixture containing SiO ２Core-shell composite particles having a pure content of 90% by weight or more are defined as silica particles. In other words, component (b) is filled as particles in a dispersed state in the pixel dividing layer. The structure of the particles of component (b) is not particularly limited, and they may have internal voids.

[0054] Examples of silica particles other than the above-mentioned particles made of silicon dioxide, particles made of silicon dioxide hydrate, and particles made of quartz glass include particles containing SiO 2 in a weight excluding water. ２ Examples of the silica particles include silica particles made of a composite oxide of silicon and a metal, in which the purity of (c) is 90% by weight or more. Examples of the metals mentioned here include zirconium, titanium, and cerium. However, when it comes to silica particles containing hafnium atoms, they are defined as a mixture of silica particles and component (c).

[0055] In order to further reduce unevenness in brightness of organic EL display devices, component (b) preferably contains silica particles having a primary particle diameter of 5 to 20 nm, and even more preferably 5 to 15 nm. The component (b) more preferably contains silica particles having an aspect ratio of 1.0 to 1.3, and even more preferably 1.0 to 1.2. Note that silica particles with an aspect ratio of 1.0 can be considered to be spherical.

[0056] For the (b) component and silica particles other than the (b) component, a thin section of the pixel dividing layer and the spacer layer is used as an observation sample, and the cross section is polished to enhance smoothness by pretreatment, preferably by ion milling, more preferably by focused ion beam (FIB) processing, and a portion located within 0.2 to 0.8 μm in the film depth direction from the outermost layer of the pixel dividing layer or the spacer layer is analyzed by transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX), whereby the elements constituting the particles can be identified from element mapping information. Transmission electron microscope-electron energy loss spectroscopy (TEM-EELS) or scanning transmission electron microscope-energy dispersive X-ray spectroscopy (STEM-EDX) can also be used for analysis.

[0057] Specifically, an image of a sample observed by transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX) at a magnification of 50,000 times is measured using an image analysis particle size distribution analyzer "Mac-View" (manufactured by MOUNTECH), which makes it possible to distinguish between silica particles that correspond to component (b) and silica particles that do not correspond to component (b). That is, 30 silica particles in the TEM image of the cross section of the pixel dividing layer are randomly selected, and the major axis, minor axis, and aspect ratio in the TEM image of each are measured, and 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 when the minor axis and major axis in the TEM image of a single silica particle are equal, i.e., when the particle is a perfect circle, the diameter is considered to be the major axis. As representative values ​​showing the characteristics of silica particles corresponding to component (b), the average value of primary particle diameter, i.e., the average value of the major axis is calculated and rounded to the nearest tenth, and the average value of aspect ratio, i.e., the average value of the aspect ratio of each silica particle corresponding to component (b) is calculated and rounded to the nearest tenth. Here, SiO 2 particles having contact points with the surfaces of particles such as particles made of polymer, organic pigment and / or inorganic pigment are used. ２ The major axis and aspect ratio of the silica particles contained in the spacer layer can also be measured in a similar manner.

[0058] The pixel dividing layer of the organic EL display device of the present invention may further 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 more than 30 nm, or silica particles having an aspect ratio (major axis / minor axis) of more than 1.5. Examples of silica particles that do not fall under component (b) include "Admafine" (registered trademark) SO-E2 and SO-E4 (both manufactured by Admatec Co., Ltd.), KE-P10, and KE-S10 (both manufactured by Nippon Shokubai Co., Ltd.).

[0059] The pixel dividing layer of the organic EL display device of the present invention further contains SiO ２The silica-based inorganic composite particles may contain less than 90% by weight of the silica component and may contain particles that do not fall under the category of silica particles in this specification. Examples of the particles that do not fall under the category of silica particles include "ATLAS" (registered trademark) 100 (manufactured by CABOT Corporation), which are organic-inorganic composite particles with a silica:polymer weight ratio of 70:30, as disclosed in JP 2018-97251 A.

[0060] The average primary particle diameter of the silica particles contained in the pixel dividing layer of the organic EL display device of the present invention is preferably 5 to 30 nm, 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, more preferably 1.0 to 1.2. That is, even if the pixel dividing 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 all of the contained silica particles have an average primary particle diameter of 5 to 30 nm and an average aspect ratio (major axis / minor axis) of 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 to one decimal place the average value of the major axis of all silica particles obtained by randomly selecting 30 particles from an image of a cross section located in a range of 0.2 to 0.8 μm from the outermost layer of the pixel dividing layer in the film depth direction using the aforementioned transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX) at a magnification of 50,000x, using an image analysis particle size distribution measuring device "Mac-View" (manufactured by MOUNTECH Co., Ltd.). The "average aspect ratio (major axis / minor axis)" referred to here is the value obtained by rounding to one decimal place the average value obtained by dividing the major axis by the minor axis for each of 30 primary particles of all silica particles obtained at random from the same image. Silica particles having an average primary particle diameter of 5 to 30 nm refer to particles having an average primary particle diameter within the range of 5 to 30 nm, and silica particles having an average aspect ratio of 1.0 to 1.3 refer to particles having an average aspect ratio within the range of 1.0 to 1.3.

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

[0062] Examples of functional groups that component (b) has on its surface include reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups, silanol groups, alkoxysilyl groups, trialkylsilyl groups, and diphenylsilyl groups. Among these, reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups are preferred for further reducing brightness unevenness. The reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups referred to here refer to groups remaining after the ethylenically unsaturated double bond groups of the surface-modifying groups containing ethylenically unsaturated double bond groups undergo radical polymerization reaction due to light and / or heat. It is more preferred that component (b) contains silica particles having reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups on their particle surfaces, and that the reactive residues of the surface-modifying groups containing ethylenically unsaturated double bond groups have a structure represented by formula (19) and / or a structure represented by formula (20). The reactive residue of the surface modifying 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 radically polymerizable groups in the molecule, as described below.

[0063]

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

[0065]

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

[0067] The 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 a silica particle, and then subjecting the ethylenically unsaturated double bond group contained in the surface modifying group to a radical polymerization reaction 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), whose reactive residue has a structure represented by formula (20), 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 a silanol group on the surface of a silica particle, and then subjecting the ethylenically unsaturated double bond group contained in the surface modifying group to a radical polymerization reaction using light and / or heat. Examples of the isocyanate compound 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 modifying group derived from an organic alkoxysilane compound having an ethylenically unsaturated double bond group and a surface modifying group derived from an isocyanate compound having an ethylenically unsaturated double bond group, it is possible to obtain component (b) whose reactive residues have a structure represented by formula (19) and a structure represented by formula (20).

[0071] In order to improve the dispersion stability of component (b) in the negative photosensitive composition for forming the pixel dividing layer, component (b) preferably contains a trialkylsilyl group, more preferably a trimethylsilyl group. Trimethylsilyl groups can be introduced into component (b) by converting hydrogen atoms in the surface silanol groups of the silica particles to trimethylsilyl groups using a trimethylsilylating agent. Examples of trimethylsilylating 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), brightness unevenness can sometimes be more stably reduced.

[0072] In order to further reduce unevenness in brightness, it is preferable that the component (b) contains silica particles having sodium atoms. The sodium atoms may exist in the form of, for example, ions (Na ＋and salts with silanol groups (Si—ONa). The sodium atom content in component (b) is preferably 100 to 5,000 ppm by weight. Silica particles containing sodium atoms can be synthesized under alkaline conditions by reacting sodium silicate, which is a strongly alkaline silicon source, with a strong mineral acid. The sodium atoms contained in silica particles can be detected in the central region corresponding to the intersection of the major and minor axes in an image of the cross section of the primary particle using the above-mentioned TEM-EDX.

[0073] The content of the component (b) is determined by the amount of SiO in the pixel dividing layer in order to suppress unevenness in brightness. ２ The silica content in the pixel dividing layer is preferably 1 to 50% by weight, more preferably 5 to 20% by weight, calculated from the same viewpoint. ２ The amount is preferably 1 to 50% by weight, more preferably 7 to 30% by weight, calculated as SiO. ２ The converted content means a content calculated based on the common technical knowledge of a person skilled in the art, excluding the weight of water in the silica particles, which varies depending on the thermal history.

[0074] The content of the component (b) relative to 100 parts by weight of the component (a) is set to SiO 2 in order to reduce uneven brightness. ２ That is, in the organic EL display device of the present invention, the content of the component (b) relative to the component (a) in the pixel dividing layer is preferably 20 to 70 parts by weight, more preferably 30 to 50 parts by weight in terms of SiO ２ The amount is preferably 20 to 70 parts by weight in terms of conversion.

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

[0076] Examples of inorganic particles containing component (c) include hafnium oxide (HfO ２), composite oxides of hafnium and metals other than hafnium, solid solutions of hafnium oxide and oxides of metals other than hafnium, hafnium oxynitride, composite oxynitrides of hafnium and metals other than hafnium, and solid solutions of hafnium oxynitrides and oxynitrides of metals other than hafnium. Among these, hafnium oxide (HfO ２ ), or a composite oxide of hafnium and a metal other than hafnium, is preferred, and a composite oxide of zirconium and hafnium (ZrO ２ -HfO ２ ) is more preferred.

[0077] As the inorganic particles containing component (c), commercially available products available in powder form can be used, such as Hafnium oxide P, Hafnium oxide R, and Hafnium oxide S (all manufactured by ATI METALS) and hafnium oxide fine particles (manufactured by Kojundo Chemical Laboratory Co., Ltd.). As an alternative method, in the process of preparing a pigment dispersion liquid containing component (a), which will be described later, the surface of a grinding medium containing component (c) can be wet-polished using mechanical energy to produce fine particles, which can then be co-dispersed with component (a), thereby allowing component (c) to be contained in the pixel division layer finally obtained.

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

[0079] In order to further reduce unevenness in brightness, it is preferable that the pixel dividing layer included in the organic EL display device of the present invention further contains (d) a phenolic resin (hereinafter, sometimes referred to as component (d)). The phenolic resin here refers to a resin having a repeating unit with a phenol skeleton. Examples of component (d) include a resin having a repeating unit represented by formula (5) and a resin having a repeating unit represented by formula (6).

[0080]

[0081]

[0082] In formula (5) and formula (6), R １１ and R １２ each independently represents a methylene group or a CH-Ar group. Ar represents a phenyl group or a phenyl group having a substituent. * represents a bonding site.

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

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

[0085] In order to further reduce unevenness in brightness, the pixel dividing layer provided in the organic EL display device of the present invention further contains (e) an acryloyl group or a methacryloyl group and a trifluoromethyl group (CF ３ It is preferable that the component (e) contains a resin having a repeating unit having an acryloyl group or a methacryloyl group and a trifluoromethyl group (CF ３ ) preferably has a structure represented by formula (7).

[0086]

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

[0088] An acryloyl group or a methacryloyl group and a trifluoromethyl group (—CF ３ ) is preferably a repeating unit represented by formula (8).

[0089]

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

[0091] In formula (8), R １６ is preferably a residue of a compound having two epoxy groups in the molecule, and R １６ Specific examples of the above preferably include structures having a cyclic structure represented by formulas (9) to (11).

[0092]

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

[0094]

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

[0096]

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

[0098] For example, the method for obtaining component (e) is as follows: in the first step, acrylic acid or methacrylic acid is reacted with the epoxy group of a compound having two epoxy groups in the molecule. In the second step, a dicarboxylic acid anhydride having a trifluoromethyl group is reacted with the hydroxyl group generated by ring-opening of the epoxy group. In order to improve the reaction rate, it is desirable to use a phase transfer catalyst, and commercially available products include tetraalkylammonium bromide and tetraalkylammonium chloride.

[0099] The pixel dividing layer provided in the organic EL display device of the present invention may contain, in addition to a resin other than the components (d) and (e) and a dispersant, a cured product of a compound having two or more radically polymerizable groups in the molecule, as described below, a photopolymerization initiator, or a decomposition product thereof.

[0100] By incorporating the above components (a) to (e) in the negative photosensitive composition, the components (a) to (e) can be incorporated into the pixel dividing layer that is finally obtained.

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

[0102] An example of a compound having four radically polymerizable groups in the molecule is "Light Acrylate" (registered trademark) PE-4A (manufactured by Kyoeisha Chemical Co., Ltd.). An example of a compound having three radically polymerizable groups in the molecule is "Aronix" (registered trademark) M-215 and M-315 (both manufactured by Toagosei Co., Ltd.). An example of a compound having two radically polymerizable groups in the molecule is "OGSOL" (registered trademark) EA-0200, EA-0250P-LT, GA-2800, GA-5060P (all manufactured by Osaka Gas Chemicals Co., Ltd.) and A-BPEF (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0103] Examples of the photopolymerization initiator 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 for i-line or mixed lines containing at least i-line. Examples of the oxime ester-based photopolymerization initiator include "ADEKA CRUISE" (registered trademark) NCI-831E (manufactured by ADEKA Corporation, hereinafter referred to as "NCI-831E"), "Irgacure" (registered trademark) OXE01, OXE02, OXE03, and OXE04 (all manufactured by BASF), and the oxime ester-based photopolymerization initiators described in WO 2016 / 008384.

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

[0105] The negative photosensitive composition may further contain a solvent. By containing a solvent, the viscosity, thixotropy, etc. of the negative photosensitive composition can be adjusted, and the thickness uniformity of the coating film can be improved. Preferred examples of the solvent 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] A method for preparing a negative photosensitive composition includes preparing a pigment dispersion containing component (a) by wet dispersion treatment, then mixing and stirring a dispersion containing component (b) and, if necessary, components (d), (e), a solvent, and other components with the pigment dispersion, and filtering the mixture if necessary. Component (b) may be subjected to wet dispersion treatment in the coexistence of component (a).

[0107] The disperser for performing the wet dispersion treatment may be a wet media disperser or a wet medialess disperser, but the use of a wet media disperser is desirable because of its excellent dispersion treatment speed and economical advantages. Examples of wet media dispersers include bead mills such as "Levomill" (registered trademark) (manufactured by Asada Iron Works), "Nano Getter" (registered trademark) (manufactured by Ashizawa Finetech), "DYNO-MILL" (registered trademark) (manufactured by Willy A. Bachofen), "Spike Mill" (registered trademark) (manufactured by Inoue Manufacturing Co., Ltd.), "Sand Grinder" (registered trademark) (manufactured by DuPont), "Ultra Apex Mill Advance" (registered trademark) (manufactured by Hiroshima Metal & Machinery Co., Ltd.), and "NEO-Alpha Mill" (registered trademark) (manufactured by AIMEX Co., Ltd.).

[0108] When the pixel dividing layer contains component (c), hafnium oxide (HfO ２ ), or a composite oxide of zirconia and hafnium (ZrO ２ -HfO ２ It is preferable to use ceramic beads having a purity of 90% by weight or more. In order to further reduce brightness unevenness, the diameter of the grinding 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 above-described spacer layer, the spacer layer formed as the second 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, in order to maintain the aperture width of the pixel division layer formed as the first layer and reduce brightness unevenness. It is more preferable to contain silica particles having a primary particle diameter of 5 to 20 nm, and even more preferable to contain silica particles having a primary particle diameter of 5 to 15 nm. It is more preferable to contain silica particles having an aspect ratio of 1.0 to 1.3, and even more preferable to contain silica particles having an aspect ratio of 1.0 to 1.2.

[0110] That is, the organic EL display device of the present invention preferably includes a spacer layer on at least a part of the surface of the pixel dividing 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 photosensitive composition can be used as the photosensitive composition for forming the spacer layer. Preferably, the same negative photosensitive composition as that for forming the pixel dividing layer is used, which not only improves the adhesion between the pixel dividing layer and the spacer layer but also reduces the amount of industrial wastewater generated when switching materials, thereby reducing the environmental impact.

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

[0113] <Calculation of optimal exposure dose> A silver alloy film (an alloy consisting of 99.00 wt % silver and 1.00 wt % copper) was formed on the entire surface of an alkali-free glass substrate measuring 150 mm long and 150 mm wide by a sputtering method. An ITO film was then formed on the entire surface by a sputtering method, thereby obtaining a glass substrate having a silver alloy film / ITO film on the entire surface of the alkali-free glass substrate.

[0114] The negative photosensitive composition was applied to the silver alloy film / ITO film side surface of the glass substrate having the silver alloy film / ITO film using a spin coater, adjusting the rotation speed so that the thickness of the final pixel dividing layer would be 1.5 μm, to obtain a coating film. The coating film was then prebaked at 100°C under atmospheric pressure for 120 seconds using a hot plate to obtain a prebaked film. Using a double-sided alignment single-sided exposure device, the negative photosensitive composition was exposed to an exposure dose of 20 to 120 mJ (mJ / cm) through a negative exposure mask (220 square light-shielding portions, each 30.0 μm long and 30.0 μm wide). ２ The prebaked film was pattern-exposed to a mixture of g, h, and i rays from an ultra-high pressure mercury lamp while changing the exposure dose stepwise in 10 mJ increments within the range of g / h: i-ray equivalent value, to obtain an exposed film having exposed and unexposed areas within its surface.

[0115] The pattern exposure was performed by contacting a negative exposure mask with the surface of the prebaked film. Then, using a compact photolithography developing device (AD-2000; manufactured by Takizawa Sangyo Co., Ltd.), the film was developed by the puddle method using a 2.38 wt % TMAH aqueous solution. The puddle method refers to a method in which the developer is shower-coated onto the surface of the exposed film for 10 seconds, and then the substrate is left to stand for a predetermined development time.

[0116] The development time was calculated by multiplying the time required for the unexposed film to be dissolved and removed in the film depth direction by 1.5. The substrate was then rinsed with deionized water for 30 seconds using a shower system, and then dried by rotating at 200 rpm for 30 seconds to obtain a developed film-formed substrate having a patterned developed film. The developed film was then heated at 250°C for 1 hour in a nitrogen atmosphere using a high-temperature inert gas oven (INH-9CD-S; manufactured by Koyo Thermo Systems Co., Ltd.) 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 dose (mJ / cm) was calculated when openings were made so that the average opening width of 10 openings in each exposure dose region was within the range of 30.0±0.1 μm. ２ The optimum exposure amount (exposure sensitivity) of the negative photosensitive composition was determined as follows:

[0117] (1) Evaluation of Optical Density (OD / μm) of Cured Film For the optical density evaluation substrates on which a 1.5 μm-thick cured film was formed obtained in Examples 1 to 11 and Comparative Examples 1 to 8, the total optical density (Total OD value) was measured at three locations on the film surface using an optical densitometer (X-Rite 361T, manufactured by X-Rite Corporation) to calculate the average value. This value was then divided by 1.5, and the resulting value was rounded to one decimal place to obtain the OD value (OD / μm) per 1.0 μm of cured film thickness. The evaluation was based on the criterion that the higher the OD / μm, the more excellent the light-blocking property of the cured film. The OD value of Tempax on which a cured film was not formed was separately measured and found to be 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 locations on the surface using a stylus film thickness measuring device (Tokyo Seimitsu Co., Ltd.; Surfcom), and the average value was rounded off to one decimal place to determine a value up to one decimal place.

[0118] (2) Evaluation of the aperture width of the pixel division layer The pixel division layer-formed substrates and pixel division layer / spacer layer-formed substrates on which pixel division layers with a thickness of 1.5 μm were formed obtained in Examples 1 to 12 and Comparative Examples 1 to 9 were observed using an FPD inspection microscope, and the aperture widths of 10 openings in the surface were measured ( FIG. 3 ). １ (μm) to the minimum opening width W ２ (μm) minus the value W ３ The smaller the value (μm), the better the result was, and a value of less than 3.0 was considered acceptable, while a value of 3.0 or more was considered unacceptable.

[0119] (3) Evaluation of Luminance Unevenness of Organic EL Display Devices The organic EL display devices obtained in Examples 1 to 12 and Comparative Examples 1 to 9 were subjected to a current of 10 mA / cm ２The display was driven by a direct current and illuminated, and pixels formed within an area of ​​16 mm long x 16 mm wide were observed by enlarging 20 central pixel locations on a monitor at a magnification of 50x, and the in-plane luminance unevenness was evaluated based on the following criteria. AA and A to C were rated as pass, and D was rated as fail. If one or more unlit pixels were observed, the display was rated as E and failed, regardless of the degree of luminance unevenness. AA: No luminance unevenness was observed. A: Very slight luminance unevenness was observed. B: Slight luminance unevenness was observed. C: Luminance unevenness was observed. D: Significant luminance unevenness was observed. E: One or more unlit pixels were observed.

[0120] Information about the various raw materials used in the Examples and Comparative Examples is provided below. Table 1 shows the content (wt %) of silica particles in each silica particle dispersion, as well as the cross-sectional analysis results of the pixel dividing layers corresponding to each silica particle dispersion used in the Examples and Comparative Examples. "MEK-ST-40": 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 wt % based on 100 wt % silica particles. "OSCAL-1421": Silica particle dispersion containing component (b) (manufactured by JGC Catalysts and Chemicals Industries, Ltd.). The solvent is isopropyl alcohol. "MEK-ST-L": Silica particle dispersion containing component (b) (manufactured by Nissan Chemical Industries, Ltd.). The solvent is methyl ethyl ketone. "Silica particle dispersion 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 was methyl ethyl ketone. "THRULYA": A silica particle dispersion not containing component (b) (manufactured by JGC Catalysts and Chemicals Industries, Ltd.). The solvent was isopropyl alcohol. "MEK-ST-ZL": A silica particle dispersion not containing component (b) (manufactured by Nissan Chemical Industries, Ltd.). The solvent was methyl ethyl ketone. "ATLAS100": Particles not containing component (b) that do not fall into the category of pigment or silica particles. "ATLAS" (registered trademark) 100 (manufactured by CABOT Corporation). Organic-inorganic composite particles (silica:polymer = weight ratio 70:30, average primary particle diameter 100 nm, primary particle diameter distribution range 70 to 130 nm, solid content 100 wt%) having a primary particle shape in which a coating layer containing silica is fixed so as to be partially embedded in the surface of organic polymer particles.

[0121]

[0122] "S0100": Irgaphor Black (registered trademark) S0100CF. A benzodifuranone-based black pigment comprising a compound represented by formula (3). This corresponds to component (a). "Bk-CBF1": The surface-coated benzofuranone-based black pigment Bk-CBF1 disclosed in Coating Example 1 of WO 2018 / 181311. The amount of silica coated is SiO per 100 parts by weight of the benzodifuranone-based black pigment comprising a compound represented by formula (3). ２ The equivalent weight of the alumina coating is 10.0 parts by weight. ２ O ３ Converted to 2.0 parts by weight. Corresponds to component (a). "Pigment dispersant 1": Pigment dispersant 1 (solid content 100% by weight) disclosed in Synthesis Example 2 of JP 2020 / 70352 A. A polymer-type dispersant having a linear polyalkyleneamine structure and a polyether-based polymer chain. "ZCR-1569H": A PGMEA solution of an epoxy acrylate resin having a biphenyl skeleton in the main chain. Solid content 70% by weight (manufactured by Nippon Kayaku Co., Ltd.). "TR4020G": A resin having a repeating unit represented by formula (5). Solid content 100% by weight (manufactured by Asahi Organic Chemicals Co., Ltd.). Corresponds to component (d). "ZAH-106": A PGMEA solution of a methacrylic polyol resin. Solid content 35% by weight (manufactured by Soken Chemical & Engineering Co., Ltd.). "DPCA-60": A compound having six radically polymerizable groups in the molecule. Solid content 100% by weight (manufactured by Nippon Kayaku Co., Ltd.). "GA-5060P": PGMEA solution of a compound having two radically polymerizable groups in the molecule. Solid content 62% by weight (manufactured by Osaka Gas Chemicals Co., Ltd.). "A-BPEF": PGMEA solution of a compound having one fluorene skeleton, two oxyethylene chains, and two radically polymerizable groups in the molecule (manufactured by Shin-Nakamura Chemical Co., Ltd.). Solid content 50% by weight.

[0123] Synthesis Example 1: Synthesis of "Polyimide Resin A" In a dry nitrogen stream, 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-neck flask.

[0124] A solution was prepared by dissolving 31.02 g of oxydiphthalic anhydride in 50.00 g of N-methylpyrrolidone, and added to the solution in the three-necked flask. The mixture was stirred for 1 hour at a liquid temperature of 20° C., and then for 4 hours at 50° C. Thereafter, 15 g of xylene was added, and the mixture was stirred for 5 hours at 150° C. while azeotroping by-produced water with xylene.

[0125] After the reaction was completed, the reaction solution was poured into 3 L of deionized water, and the resulting solid precipitate was collected by filtration. The resulting 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 the form of powder with a solid content of 100% by weight and had a weight-average molecular weight (Mw) of 27,000.

[0126] Synthesis Example 2: Synthesis of "Epoxy Acrylate Resin Solution B" Into a three-neck 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, and the liquid temperature was raised to 100°C with stirring. After stirring for 4 hours to allow the reaction, heating was stopped and the liquid temperature 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 acid anhydride having two trifluoromethyl groups in the molecule, were added to the solution in the three-necked flask, and the liquid temperature was again raised to 100°C while stirring, and then the mixture was stirred for 4 hours to cause a reaction.

[0128] Next, 6.09 g (0.04 mol) of 1,2,3,6-tetrahydrophthalic anhydride was added as an end-capping agent, and the mixture was stirred at 90°C for 3 hours to allow the reaction to proceed, followed by cooling to obtain a resin solution containing a resin having a weight-average molecular weight (Mw) of 3,800 and having a repeating unit represented by formula (12), which corresponds to component (e).

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

[0130]

[0131] In formula (12), * represents a binding site.

[0132] Synthesis Example 3: Synthesis of "Silica Particle Dispersion A" To a three-neck 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 0.01 g of methoquinone as a polymerization inhibitor was further added. The mixture was stirred for 10 minutes, and then the liquid temperature 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, and this solution was added dropwise in equal amounts stepwise over 10 minutes. The solution was stirred for 2 hours while maintaining the liquid temperature at 50°C to allow a dehydration condensation reaction to proceed, and then cooled to 25°C.

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

[0135] Synthesis Example 4: Synthesis of "Silica Particle Dispersion B" To a three-neck flask containing 104.50 g of methyl ethyl ketone, 142.50 g of MEK-ST-40 and 0.01 g of methoquinone were added, and the mixture was stirred for 10 minutes, and then the liquid temperature 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, and this solution was added dropwise in equal amounts stepwise over 10 minutes. The solution was stirred for 3 hours while maintaining the liquid temperature at 50°C to allow the urethanization reaction to proceed, and then cooled to 25°C.

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

[0138] Preparation Example 1: Preparation of Pigment Dispersion Liquid 1 30.00 g of Pigment Dispersant 1 was added to 770.00 g of PGMEA as a solvent and stirred for 5 minutes, after which 100.00 g of ZCR-1569H was added and stirred for 30 minutes. Furthermore, 100.00 g of S0100 was added as component (a), and the mixture was stirred for 30 minutes to obtain a preliminary stirred liquid.

[0139] The pre-stirred liquid was sent to a vertical bead mill whose vessel was filled with grinding media made of a 0.4 mmφ composite oxide (zirconium oxide: hafnium oxide: yttrium oxide: aluminum oxide = weight ratio 93.3:1.5:4.9:0.3, manufactured by Toray Industries, Inc.) at a filling rate of 75% by volume, and a first wet media dispersion treatment was carried out using a circulation system at a peripheral speed of 8 m / s for 3 hours.

[0140] The solution was then transferred to a vertical bead mill containing a vessel filled with 75% by volume of 0.05 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.), and subjected to a second wet media dispersion treatment using a circulation system at a peripheral speed of 9 m / s for 6 hours. The resulting solution was then filtered through a 0.8 μm filter to prepare Pigment Dispersion Liquid 1 with a solids content of 20.00 wt %. The blend weights of the raw materials are shown in Table 2.

[0141]

[0142] (Preparation Example 2: Preparation of Pigment Dispersion 2) Pigment Dispersion 2 with a solids content of 20.00 wt % was obtained in the same manner as in Preparation Example 1, except that the 0.4 mmφ composite oxide grinding media was replaced with 0.3 mmφ silicon nitride grinding media, the first wet media dispersion treatment was carried out at a peripheral speed of 9 m / s for 10 hours, and the second wet media dispersion treatment was not carried out. The blend 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 solvent, 30.00 g of Pigment Dispersant 1 was added and stirred for 5 minutes, and then 100.00 g of ZCR-1569H was added and stirred for 30 minutes. Further, 40.00 g of C.I. Pigment Red 177, 40.00 g of C.I. Pigment Blue 15:6, and 20.00 g of C.I. Pigment Yellow 24 were added in this order, and the mixture was stirred for 30 minutes to obtain a preliminary stirred liquid.

[0144] Thereafter, wet media dispersion treatment and filtration were carried out in the same manner as in Preparation Example 1 to prepare Pigment Dispersion Liquid 3 with a solid content of 20.00% by weight. The blend 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 method of Preparation Example 1 disclosed in Patent Document 1, as follows: 34.50 g of SOLSPERSE 20000 (manufactured by Lubrizol Corporation: solids content 100 wt%) as a dispersant and 782.00 g of MBA as a solvent were mixed and stirred for 10 minutes, after which 103.50 g of S0100 was added and stirred for 30 minutes. A wet media dispersion treatment was performed using a horizontal bead mill filled with 0.40 mm zirconia beads to obtain Pigment Dispersion 4 with a solids content of 15.00 wt%. The blend weights of each raw material are shown in Table 2. The number average particle size was measured using a zeta potential / particle size / 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, as follows: 27.60 g of SOLSPERSE 20000, 782.00 g of MBA, and 27.60 g of Polyimide Resin A were mixed and stirred for 10 minutes, and then 82.80 g of Bk-CBF1 was added and stirred for 30 minutes. Using a horizontal bead mill filled with 0.40 mmφ zirconia beads, the mixture was subjected to a wet media dispersion treatment in the same manner as in Preparation Example 4, so that the number average particle size was 100 nm, thereby obtaining Pigment Dispersion 5 with a solids content of 15.00 wt %. The blend weights of each raw material are shown in Table 2.

[0147] (Preparation Example 6: Preparation of Organic-Inorganic Composite Particle Dispersion 1) 10.00 g of pigment dispersant 1 was added to 900.00 g of PGMEA solvent and stirred for 30 minutes. Further, 90.00 g of ATLAS100 was added, and the mixture was stirred for 30 minutes to obtain a pre-stirred liquid. The pre-stirred liquid was sent to a vertical bead mill whose vessel was filled with 0.3 mmφ silicon nitride grinding media at a filling rate of 75% by volume, and 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 an organic-inorganic composite particle dispersion 1 having a solids content of 10.00 wt % and not containing component (b). The blending weights of each raw material are shown in Table 2.

[0148] Example 1 Under 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. To this mixture, 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 transparent preparation. 16.69 g of Pigment Dispersion 1 was mixed with this preparation and stirred for 30 minutes to prepare Negative Photosensitive Composition 1 with a solids content of 15.00 wt %. The blend weights of each raw material are shown in Table 3.

[0149]

[0150] Negative photosensitive composition 1 was applied to the surface of a transparent glass substrate "Tempax (manufactured by AGC Technoglass Co., Ltd.)" using a spin coater, adjusting the rotation speed so that the final thickness of the cured film would be 1.5 μm, to obtain a coating film. The coating film was prebaked at 100° C. under atmospheric pressure for 120 seconds using a hot plate (SCW-636; manufactured by Dainippon Screen Mfg. Co., Ltd.) to obtain a prebaked film. Using a double-sided alignment single-sided exposure device, the g, h, and i mixed rays of an ultra-high pressure mercury lamp were applied to the surface as described above. The entire surface of the prebaked film was irradiated with the optimum exposure dose determined by the method described above to obtain an exposed film. The film was then developed, rinsed, and dried in the same manner as when calculating the optimum exposure dose, yielding a solid developed film. The developed film was heated in air at 250°C for 1 hour using a high-temperature inert gas oven (INH-9CD-S; manufactured by Koyo Thermo Systems Co., Ltd.) to obtain a substrate for optical density evaluation having a solid cured film with a film thickness of 1.5 μm, and the optical density (OD / μm) was evaluated by the method described above. The evaluation results are shown in Table 4.

[0151]

[0152] Furthermore, a pixel dividing layer made of a cured film of the negative-type photosensitive composition 1 and an organic EL display device having the pixel dividing layer were produced by the following method. Fig. 2 shows the production process of the organic EL display device, including the step of forming the pixel dividing layer.

[0153] A silver alloy (an alloy consisting of 99.00 wt. % silver and 1.00 wt. % copper) was formed on 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 immersed in a silver alloy etching solution SEA-1 at a solution temperature of 30°C and etched to obtain a patterned silver alloy film 12 with a thickness of 50 nm. Furthermore, an ITO film was formed on the entire surface by sputtering. The substrate was immersed in a 5 wt. % oxalic acid solution at a solution 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-formed substrate was obtained, comprising a first electrode formed on the surface of the alkali-free glass substrate, the first electrode consisting of a laminated pattern of a silver alloy film and an ITO film.

[0154] Negative photosensitive composition 1 was applied to the surface of the first electrode-forming substrate using a spin coater, adjusting the rotation speed so that the final pixel division layer thickness was 1.5 μm, to obtain a coating film. The coating film was then prebaked at 100°C for 120 seconds using a hot plate under atmospheric pressure to obtain a prebaked film. Using a double-sided alignment single-sided exposure device, the prebaked film was pattern-exposed using a negative exposure mask (220 square light-shielding areas, 30.0 μm long and 30.0 μm wide) at the optimal exposure dose determined by the above-mentioned method to obtain an exposed film. The pattern exposure was performed by contacting the negative exposure mask with the surface of the prebaked film. The film was then developed, rinsed, and dried in the same manner as when calculating the optimal exposure dose, to obtain a patterned developed film. The developed film was heated in a high-temperature inert gas oven at 250°C for 1 hour in a nitrogen atmosphere to obtain a pixel division layer-forming substrate having a pixel division layer 14 with a thickness of 1.5 µm and 220 openings in an area of ​​30 mm length x 30 mm width 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, the organic EL layer 15 including the light-emitting layer is formed in the opening of the pixel dividing layer 14 by vacuum deposition under a vacuum of 1×10 －３ Under evaporation conditions of 0.1 Pa or less, the pixel division layer-forming substrate was rotated relative to the evaporation source, and first, a 10 nm thick film of compound (HT-1) represented by formula (13) was formed as a hole injection layer, and a 50 nm thick film of compound (HT-2) represented by formula (14) was formed as a hole transport layer. Next, a 40 nm thick film of compound (GH-1) represented by formula (15) was deposited as a host material and a 40 nm thick film of compound (GD-1) represented by formula (16) was deposited on the emitting layer. Next, a 1:1 volume ratio of compound (ET-1) represented by formula (17) and compound (LiQ) represented by formula (18) were laminated as electron transport materials to a thickness of 40 nm.

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162] Next, a 2-nm thick layer of compound (LiQ) was vapor-deposited, followed by vapor deposition of a silver / magnesium alloy (volume ratio 10:1) to a thickness of 150 nm to form the second electrode 16. Next, a cap-shaped glass plate was attached and sealed using an epoxy resin adhesive under a low-humidity / nitrogen atmosphere, yielding an organic EL display device with an array of green light-emitting pixels. The layers constituting the organic EL layer 15 are significantly thinner than the pixel division layer described above, and a stylus-type film thickness measurement device cannot achieve high measurement accuracy. Therefore, each layer was measured using a quartz crystal oscillator film thickness monitor, suitable for thin films less than 100 nm thick. The film thickness was determined by rounding the average of three in-plane values ​​to the nearest tenth. The brightness unevenness of the fabricated organic EL display device was evaluated using the method described above. After evaluating the brightness unevenness, the organic EL display device was disassembled, and the content of component (c) in the pixel division layer was quantified using ICP atomic emission spectroscopy (detection limit of hafnium atoms: 0.2 ppm by weight), resulting in a value of 3.0 ppm by weight. Furthermore, TEM-EDX analysis confirmed that the pixel dividing layer contained component (b). In addition to the primary particle size and aspect ratio of component (b), the average primary particle size (nm) and average aspect ratio of the silica particles were also measured. The evaluation results are shown in Table 4.

[0163] Examples 2 and 3 Negative-type photosensitive compositions 2 and 3 were prepared using OSCAL-1421 or MEK-ST-L instead of MEK-ST-40 in the amounts shown in Table 3. The optical density of the cured film, the aperture width of the pixel dividing layer, and the brightness unevenness 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 dividing layer was quantified. Furthermore, analysis was performed using TEM-EDX to confirm that the pixel dividing layer contained component (b). In addition to the primary particle size and aspect ratio of component (b), the average primary particle size (nm) and average aspect ratio of the silica particles were measured. The evaluation results are shown in Table 4.

[0164] Examples 4 to 7 Negative-type photosensitive compositions 4 to 7 were prepared using pigment dispersions 1 to 3 and epoxy acrylate resin solution B in the amounts shown in Table 5. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness unevenness 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 was performed using TEM-EDX to confirm that the pixel division layer contained component (b). In addition to the primary particle size and aspect ratio of component (b), the average primary particle size (nm) and average aspect ratio of the silica particles were measured. The evaluation results are shown in Table 6.

[0165]

[0166]

[0167] Comparative Example 1 Under 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 solids content of 15.00 wt %. The blend weights of each raw material are shown in Table 7. The optical density of the cured film, the aperture width of the pixel dividing layer, and the brightness unevenness of the organic EL display device were evaluated in the same manner as in Example 1. In analysis by ICP atomic emission spectroscopy, component (c) was not detected in the pixel dividing layer (lower detection limit: less than 0.2 ppm by weight). Furthermore, analysis by TEM-EDX confirmed that the pixel dividing layer did not contain component (b). The above evaluation results are shown in Table 8.

[0168]

[0169]

[0170] (Comparative Example 2) Negative photosensitive compositions 9 were prepared using pigment dispersion 5 instead of pigment dispersion 4 in the blending amounts shown in Table 7, and the optical density of the cured film, the aperture width of the pixel division layer, and the brightness unevenness of the organic EL display device were evaluated in the same manner as in Example 1. Analysis by ICP atomic emission spectroscopy did not detect component (c) in the pixel division layer. 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 and 4) Negative-type photosensitive compositions 10 and 11 were prepared in the amounts shown in Table 7, using Pigment Dispersion 2 instead of Pigment Dispersion 1 and THRULYA or MEK-ST-ZL instead of MEK-ST-40. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness unevenness of the organic EL display device were evaluated in the same manner as in Example 1. In ICP atomic emission spectroscopy analysis, 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). The measurement results of the average primary particle diameter (nm) and average aspect ratio of the silica particles are shown in Table 8. The above evaluation results are also shown in Table 8.

[0172] Example 8 A negative photosensitive composition 12 was prepared using silica particle dispersion A instead of MEK-ST-40 in the blending amounts shown in Table 9, and the optical density of the cured film, the aperture width of the pixel dividing layer, and the brightness unevenness of the organic EL display device were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 10. Analysis by ICP atomic emission spectroscopy showed that the content of component (c) in the pixel dividing layer was 3.0 ppm by weight. ２９ Si nuclear magnetic resonance method, １ The pixel dividing layer obtained from the negative photosensitive composition 12 was analyzed by H nuclear magnetic resonance spectroscopy and TEM-EDX. １６ is a methyl group, and R １７The pixel dividing layer contained component (b) having, as a reactive residue, a structure in which j and k are each a propylene group, m is 3, and n is 0. Furthermore, analysis was performed using TEM-EDX to measure the primary particle size and aspect ratio of component (b), as well as the average primary particle size (nm) and average aspect ratio of the silica particles. The evaluation results are shown in Table 10.

[0173]

[0174]

[0175] Example 9 A negative photosensitive composition 13 was prepared using silica particle dispersion B instead of MEK-ST-40 in the blending amounts shown in Table 9, and the optical density of the cured film, the aperture width of the pixel dividing layer, and the brightness unevenness of the organic EL display device were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 10. Analysis by ICP atomic emission spectroscopy showed that the content of component (c) in the pixel dividing layer was 3.0 ppm by weight. ２９ Si nuclear magnetic resonance method, １ The pixel dividing layer obtained from the negative photosensitive composition 13 was analyzed by H nuclear magnetic resonance spectroscopy and TEM-EDX. In the structure represented by formula (20), R １９ is a methyl group, and R ２０ The pixel dividing layer contained component (b) having, as a reactive residue, a structure in which r is an oxyethylene group and r is 1. Furthermore, analysis was performed using TEM-EDX to measure the primary particle size and aspect ratio of component (b), as well as the average primary particle size (nm) and average aspect ratio of the silica particles. The evaluation results are shown in Table 10.

[0176] Comparative Examples 5 and 6 Negative-type photosensitive compositions 14 and 15 were prepared using Pigment Dispersion 2 instead of Pigment Dispersion 1 and MEK-ST-ZL instead of MEK-ST-40 in the amounts shown in Table 9. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness unevenness 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 ICP atomic emission spectroscopy analysis, component (c) was not detected in the pixel division layer. Furthermore, analysis was performed using TEM-EDX to confirm 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 above evaluation results are shown in Table 10.

[0177] (Examples 10 and 11) Negative-type photosensitive compositions 16 and 17 were prepared using the blending amounts shown in Table 11, but varying the content of component (b). The optical density of the cured film, the aperture width of the pixel dividing layer, and the brightness unevenness 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 dividing layer was quantified. Furthermore, analysis was performed using TEM-EDX to confirm that the pixel dividing layer contained component (b). In addition to the primary particle size and aspect ratio of component (b), the average primary particle size (nm) and average aspect ratio of the silica particles were also measured. The evaluation results are shown in Table 12.

[0178]

[0179]

[0180] (Comparative Examples 7 and 8) Negative-type photosensitive compositions 18 and 19 were prepared in the formulations shown in Table 11 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. The optical density of the cured film, the aperture width of the pixel division layer, and the brightness unevenness 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 was performed using TEM-EDX, and it was confirmed that the pixel division layer did not contain component (b). The evaluation results are shown in Table 12.

[0181] Example 12 Using the negative photosensitive composition 1, a pixel dividing layer-forming substrate having a pixel dividing layer 17 was additionally produced in the same manner as in Example 1.

[0182] The negative photosensitive composition 1 was applied to the entire surface of the pixel dividing layer 17 and the openings 18 of the pixel dividing layer 17 using a spin coater, adjusting the rotation speed so that the thickness of the final pixel dividing layer would be 1.8 μm, to obtain a coating film. Furthermore, using a hot plate, the coating film was prebaked at 100°C under atmospheric pressure for 120 seconds to obtain a prebaked film. Using a double-sided alignment single-sided exposure device, a negative exposure mask (having 50 square openings, each 45.0 μm long and 45.0 μm wide) was used to expose the prebaked film to a pattern so that the developed film, described below, would be 45.0 μm long and 45.0 μm wide, to obtain an exposed film. Next, using a small photolithography developing device (AD-2000; manufactured by Takizawa Sangyo Co., Ltd.), the film was developed using a paddle system with a 2.38 wt% TMAH aqueous solution. The development time was calculated by multiplying the time required for the unexposed film in the openings 18 of the pixel division layer 17 to be dissolved and removed in the film depth direction by 1.5. The substrate was then rinsed with deionized water for 30 seconds using a shower method, and then dried by rotating at 200 rpm for 30 seconds to obtain a developed film-formed substrate having a patterned developed film. The developed film was then heated at 250°C under a nitrogen atmosphere using a high-temperature inert gas oven for 1 hour to obtain a pixel division layer / spacer layer-formed substrate ( FIG. 4 ) having a 1.8 μm-thick spacer layer 19 on a portion of the surface of the 1.5 μm-thick pixel division layer 17. The results of evaluating the opening width of the pixel division layer using the above-mentioned method are shown in Table 13.

[0183]

[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 division layer / spacer layer-formed substrate was used instead of the pixel division layer-formed substrate having the pixel division layer 14. An organic EL display device was fabricated, and brightness unevenness was evaluated, and the content of component (c) in the pixel division layer was quantified. Furthermore, analysis was performed using TEM-EDX, and it was confirmed that the spacer layer contained silica particles with a primary particle diameter of 12 nm and an aspect ratio of 1.1. The above 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 method for measuring component (b) in the pixel division layer in Example 1.

[0185] Comparative Example 9 A pixel division layer-forming substrate including pixel division layer 17 was additionally prepared in the same manner as in Example 1, except that negative photosensitive composition 8 was used. Next, a pixel division layer / spacer layer-forming substrate and an organic EL display device were prepared in the same manner as in Example 12, except that negative photosensitive composition 8 was used instead of negative photosensitive composition 1, and the brightness unevenness was evaluated, and the content of component (c) in the pixel division layer was quantified. In addition, analysis was performed using TEM-EDX, and it was 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 having pixel dividing layers containing the component (b) in Examples 1 to 11 have a maximum opening width W １ and minimum opening width W ２ Difference W ３ The values ​​were small and the brightness unevenness was excellent in that it was small. Among them, in addition to Example 6 containing the component (e), Examples 8 to 9 containing the component (b) having a structure represented by formula (19) or a structure represented by formula (20) as a reactive residue were particularly excellent in that they had little brightness unevenness. On the other hand, in Comparative Examples 4 to 6 containing only silica particles that do not correspond to the component (b), no improvement in brightness unevenness was observed even when the content of silica particles or the content of a compound having two or more radically polymerizable groups in the molecule was increased. Furthermore, in Comparative Examples 7 and 8 containing organic-inorganic composite particles that do not correspond to the component (b) even though they contained silica, the difference W ３ On the other hand, in Example 12, which includes a spacer layer, 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 are contained, and the average value and difference W of the aperture width of the pixel division layer in Example 1 are reduced. ３ It was found that the value of was able to be maintained and was superior to Comparative Example 9. From the above, it was confirmed that the organic EL display device of the present invention is useful.

[0187] DESCRIPTION OF SYMBOLS 1: TFT 2: Wiring 3: TFT insulating layer 4: Planarizing layer 5: First electrode 6: Substrate 7: Contact hole 8: Pixel dividing layer 9: Light-emitting pixel 10: Second electrode 11: Alkali-free glass substrate 12: Silver alloy film 13: ITO film 14: Pixel dividing layer 15: Organic EL layer 16: Second electrode 17: Pixel dividing layer 18: Opening 19: Spacer layer 20: Alkali-free glass substrate 21: Silver alloy film 22: ITO film

Claims

1. An organic electroluminescence display device comprising 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, (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, wherein the phenolic resin has a structure represented by 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 phenyl group having a substituent. * represents a bonding site.)

2. 2. The organic electroluminescence display device according to claim 1, wherein the pixel dividing layer contains silica particles having an average primary particle diameter of 5 to 30 nm and an average aspect ratio (major axis / minor axis) of 1.0 to 1.

3.

3. The content of the component (b) relative to 100 parts by weight of the component (a) is SiO ２ 3. The organic electroluminescence display device according to claim 1, wherein the amount of the organic electroluminescence material is 20 to 70 parts by weight in terms of conversion.

4. 4. The organic electroluminescence display device according to claim 1, wherein the component (b) contains silica particles having sodium atoms.

5. The organic electroluminescence display device according to any one of claims 1 to 4, further comprising a spacer layer on at least a part of a surface of the pixel division layer, the spacer layer containing 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. 6. The organic EL display device according to claim 1, 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】 【Chemistry 3】 (In formula (1) and formula (2), R １ ~R １０ each independently represents 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, on the particle surface, a reaction residue of a surface modifying group containing an ethylenically unsaturated double bond group, and the reaction residue of the surface modifying 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 represents a hydrogen atom or a methyl group. １７ represents a divalent hydrocarbon group having 1 to 7 carbon atoms. j and k are integers, each independently representing 0 or 1. However, when j is 1, k is 1. １ represents the bonding site with the carbon atom. * ２ R represents a bonding site between an oxygen atom bonded to a silicon atom, which is present on the surface of the silica particle. １８ represents an alkyl group having 1 to 3 carbon atoms. m and n are integers, m represents 1 to 3, and n represents 0 to 2, provided that m+n=3 is satisfied. 【Chemistry 5】 (In formula (20), R １９ represents a hydrogen atom or a methyl group. ２０ represents an oxyalkylene group having 1 to 3 carbon atoms. r is an integer from 1 to 4. ３ represents the bonding site with the carbon atom. * ４ represents a bonding site between an oxygen atom bonded to a silicon atom, which is present on the surface of the silica particle.)

8. 8. The organic electroluminescence display device according to claim 1, wherein the pixel dividing layer contains (c) 1 to 50 ppm by weight of hafnium atoms.

9. An organic electroluminescence display device according to claim 1, wherein the pixel division layer contains (e) a resin having a repeating unit having an acryloyl group or a methacryloyl group, and a trifluoromethyl group.

10. The organic electroluminescence 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). 【Chemistry 6】 (In formula (7), R 13 represents a hydrogen atom or a methyl group. * represents a bonding site.) 11. An organic electroluminescence display device according to any one of claims 1 to 10, wherein the optical density per 1 μm of film thickness of the pixel division layer is 0.7 to 1.

2.

12. An organic electroluminescence display device comprising 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, (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 a repeating unit having an acryloyl group or a methacryloyl group, and a trifluoromethyl group, wherein the repeating unit having an acryloyl group or a methacryloyl group, and a trifluoromethyl group has a structure represented by formula (7). 【Chemistry 7】 (In formula (7), R 13 represents a hydrogen atom or a methyl group. * represents a bonding site.)

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