JP2024044445A - Organic EL display device - Google Patents

Abstract

[Problem] To provide an organic EL display device that can be driven at a low voltage, has a small leakage current, and is highly reliable by including a dam section in the pixel division layer and a metal-doped layer in the organic EL layer. [Solution] An organic EL display device having a substrate having a first electrode and a pixel division layer on a base material, and further an organic EL layer and a second electrode, wherein the pixel division layer includes a pixel opening, a pixel division section, and a dam section, and the organic EL layer includes an alkali metal-doped layer and/or a rare earth metal-doped layer. [Selected Figure] Figure 1

Description

The present invention relates to an organic EL display device having a plurality of display pixels formed in a matrix.

Organic EL display devices are attracting attention as next-generation flat panel displays. Organic EL is electroluminescence of an organic EL layer made of an organic compound provided between two electrodes. A display device that uses organic EL light emitting elements as display pixels is an organic EL display device. Self-emitting organic EL display devices are capable of wide viewing angles, high-speed response, and high-contrast image display, and can be made thinner, lighter, and more flexible by using substrates such as thin glass or plastic resin. Because of this, research and development has been actively conducted in recent years.

In order to reduce power consumption, organic EL light-emitting elements are required to be driven at lower voltages. In order to drive organic EL light-emitting elements at low voltages, it is important to reduce the injection barrier for carriers such as holes and electrons that are necessary for light emission. To achieve this, technology has been developed to achieve lower voltages by doping metals into the organic layer (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 10-270171

However, while the use of technology that dopes metals into the organic layer does indeed have the effect of lowering the voltage, it also causes a problem of poor light emission due to leakage current between adjacent display pixels, known as crosstalk. Specifically, even display pixels that do not actually need to emit light emit light, resulting in a decrease in display quality. Therefore, the object of the present invention is to provide an organic EL display device that can be driven at a low voltage, prevents crosstalk, and has high bending reliability, by providing a metal-doped organic layer and a dam section in the pixel division layer.

In order to achieve the above object, an organic EL display device of the present invention has the following configuration.
(1) An organic EL display device having a substrate having a first electrode and a pixel division layer on a base material, and further having an organic EL layer and a second electrode, wherein the pixel division layer includes a pixel opening, a pixel division portion, and a dam portion, and the organic EL layer includes an alkali metal-doped layer and/or a rare earth metal-doped layer.
(2) The organic electroluminescence display device according to (1), wherein the alkali metal-doped layer and/or the rare earth metal-doped layer contains a compound having one or more skeletons selected from the group consisting of a phenanthroline skeleton, a triazine skeleton, a bipyridine skeleton, a terpyridine skeleton, and a phosphine oxide skeleton.
(3) The organic electroluminescence display device according to (1), wherein the alkali metal-doped layer and/or the rare earth metal-doped layer contains a compound having a phenanthroline skeleton.
(4) The organic electroluminescence display device according to (1), wherein the alkali metal-doped layer and/or the rare earth metal-doped layer contains a compound having a polymer of a phenanthroline skeleton.
(5) The organic electroluminescence display device according to (1), wherein the alkali metal-doped layer and/or the rare earth metal-doped layer contains a compound having a terpyridine skeleton.
(6) The organic electroluminescence display device according to any one of (1) to (5), wherein the dam portion has a convex structure.
(7) The organic electroluminescence display device according to any one of (1) to (5), wherein the dam portion has a concave structure.
(8) The organic electroluminescence display device according to (6) or (7), wherein the dam portion has a taper angle of 91 to 120°.
(9) The organic electroluminescence display device according to (6) or (7), wherein the dam portion has a taper angle of 50 to 90°.
(10) The organic electroluminescence display device according to (9), wherein the thickness of the alkali metal-doped layer and/or the rare earth metal-doped layer on the tapered surface of the dam portion is 0.5 nm or more and 0.5 times or less the thickness in the pixel division portion.
(11) The organic electroluminescence display device according to any one of (1) to (10), wherein the pixel dividing portion has a surface roughness Ra of 0.1 nm or more and 20 nm or less.
(12) The organic electroluminescence display device according to any one of (1) to (11), wherein the surface roughness Ra of the top surface of the dam portion of the convex structure and/or the bottom surface of the dam portion of the concave structure is 5 nm or more and 50 nm or less.
(13) The organic electroluminescence display device according to any one of (1) to (12), wherein the pixel division layer contains silica particles having a primary particle diameter of 5 to 30 nm.

The present invention provides an organic EL display device that operates at a low voltage, has a small leakage current, and is highly reliable when folded.

1 is a schematic cross-sectional view of an organic EL display device according to the present invention. 1 is a schematic cross-sectional view of a substrate according to an embodiment of the present invention. 5 is a schematic diagram of a taper angle of a pixel division portion in the present invention. FIG. It is a schematic diagram of the forward taper shape of the convex structure in this invention. FIG. 2 is a schematic diagram of an inverse tapered shape of a convex structure in the present invention. It is a schematic diagram of the forward taper shape of the concave structure in this invention. FIG. 3 is a schematic diagram of an inverted tapered shape of a concave structure in the present invention. It is a schematic diagram of the taper angle of the reverse taper shape of the convex structure in this invention. It is a schematic diagram of the taper angle of the reverse taper shape of the concave structure in this invention. It is a schematic diagram of the taper angle of the forward taper shape of the convex structure in this invention. It is a schematic diagram of the taper angle of the forward taper shape of the concave structure in this invention. FIG. 2 is a schematic diagram showing the thickness of a metal-doped layer in the present invention. It is a schematic diagram of Ra1 and Ra2 in this invention. It is a schematic diagram of Ra1 and Ra2 in this invention. 1 is a schematic cross-sectional view of an organic EL display device according to the present invention. FIG. 3 is a schematic diagram of a pixel dividing section and a dam section according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a bending test according to an embodiment of the present invention. 1 is a schematic diagram of an organic EL display device according to an embodiment of the present invention.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as an "embodiment") will be described in detail. Note that the present invention should not be limited only by the embodiments described below.

<Organic EL display device>
The organic EL display device of the present invention is an organic EL display device having a plurality of display pixels formed in a matrix. The organic EL display device is roughly classified into a top emission type and a bottom emission type according to the direction of extraction of light emitted from the organic EL layer, but is not particularly limited thereto. The organic EL display device is also roughly classified into a passive driving type in which opposing electrodes are divided into columns and rows and only display pixels sandwiched between the electrodes are made to emit light, and an active driving type in which a driving circuit such as a TFT is provided for each display pixel and controlled, but is not particularly limited thereto. However, in either case, the crosstalk which is the subject of the present invention refers to a leakage current generated between the first electrodes which are electrodes on the substrate side.

The organic EL display device of the present invention is an organic EL display device having a substrate having a first electrode and a pixel division layer on a base material, and further an organic EL layer and a second electrode, the pixel division layer including a pixel opening, a pixel division portion, and a dam portion, and the organic EL layer including an alkali metal-doped layer and/or a rare earth metal-doped layer. In the present invention, the alkali metal-doped layer and/or the rare earth metal-doped layer may be collectively referred to as a metal-doped layer.

FIG. 1 shows a schematic cross-sectional view of an organic EL display device that is an example of the present invention. The organic EL display device has a first electrode 2 on a base material 1. The organic EL display device further has a pixel dividing layer, and the pixel opening 3 of the pixel dividing layer exists on the first electrode and becomes a display pixel. In addition, a pixel dividing layer is formed in the area where the first electrode 2 is not present on the base material 1 (hereinafter, the area where the first electrode 2 is not present on the base material 1 may be referred to as the gap of the first electrode). It has a pixel dividing section 4 and a dam section 5. In an organic EL display device, a unit having a first electrode and a pixel dividing layer on such a base material is referred to as a substrate. Furthermore, by having an organic EL layer 6 and a second electrode 7 on the substrate, it becomes an organic EL display device.

<Substrate>
FIG. 2 shows a schematic cross-sectional view of a substrate according to an embodiment of the present invention. In the organic EL display device of the present invention, the substrate is a minimum unit consisting of only the substrate 1, the first electrode 2, the pixel division layer 4, and the dam portion 5 described below. If the substrate has such a minimum unit, it may further have wiring and TFT 8 as a driving circuit, sensors and pattern antennas, a planarization layer 9, and the like. However, in the present invention, wiring, TFT, sensors and pattern antennas, and the planarization layer, which are the underlayers of the first electrode, are all treated as part of the substrate. In addition to TFT, it is preferable to provide a planarization layer in a substrate that integrates multiple functions such as a camera, sensors for ID and fingerprint reading, illuminance, and pattern antennas for communication and power supply. By providing a planarization layer, unevenness of wiring and TFT can be covered before the first electrode is formed, and the substrate can be planarized. By planarizing the substrate, defects in the first electrode and pixel division layer provided on the substrate can be prevented, and a high-quality substrate can be obtained.

<Base material>
Among the base material 1 in FIG. 1 and the base material 1 in FIG. 2, the base 1a of the base material below the TFT 8 is appropriately selected from metal, glass, resin film, etc. that is preferable for supporting the display device and transporting it in the post-process. can do. In particular, when flexibility is required, a resin film is preferred.

As the glass, soda lime glass, non-alkali glass, etc. can be used. The thickness of the glass should be sufficient to maintain mechanical strength. Regarding the material of the glass, alkali-free glass is preferable because fewer ions are eluted from the glass, but soda lime glass coated with a barrier coating such as SiO ₂ may also be used.

As a material for the resin film, a resin material selected from polybenzoxazole resin, polyamideimide resin, polyimide resin, polyamide resin, and poly(p-xylylene) resin is preferable because of its excellent light transmission. The substrate may contain these resin materials alone or in combination.

For example, when forming a substrate from polyimide resin, it can be formed by applying a solution containing a polyamic acid resin (including partially imidized polyamic acid), which is a precursor of polyimide resin, or a soluble polyimide resin, to a supporting substrate and baking it.

Further, since the above-described light-emitting element is known to be sensitive to oxygen and moisture, a gas barrier layer may be provided as appropriate as a structure of the base material. In particular, when the base material is a resin film, a highly reliable display device can be obtained by laminating and using inorganic thin films. Furthermore, the base material may be provided with wiring, TFTs, a planarization layer, and the like.

<First electrode>
The first electrode 2 in the present invention needs to be a light-transmissive electrode in the case of a bottom-emission type, and a light-reflective electrode in the case of a top-emission type.

For bottom emission types, for example, conductive metal oxides such as transparent tin oxide, indium oxide, and indium tin oxide (ITO), metals such as gold, silver, and chromium, inorganic conductive substances such as copper iodide and copper sulfide, and conductive polymers such as polythiophene, polypyrrole, and polyaniline can be used, but are not limited thereto.

For top emission type, a material that shows high reflectance of visible light at a certain film thickness and low electrical resistance is preferable. Furthermore, material selection is also required in terms of subsequent wet etching and cleaning, and weather resistance in storage and use environments. In particular, Ag or Ag alloy films mainly containing Ag are useful because of their high reflectance. Ag alloy films can be made of AgPdCu or AgTiCu, which contain Ag as the main component, and it is preferable to laminate these Ag alloy films with oxide conductive films such as ITO and IZO films, because low contact resistance with the organic EL layer can be achieved. In addition, Al or Al alloy films mainly containing Al are also good as the first electrode of the top emission type. An Al-Ni alloy film containing 0.1 to 2 atomic % of Ni is preferable because it has a high reflectance comparable to that of pure Al. In addition, reflective metal films such as molybdenum (Mo) and tungsten (W) can also be used.

The electrical resistance of the first electrode is not limited as long as it can supply sufficient current to light the light-emitting element, but low resistance is preferable from the viewpoint of power consumption of the light-emitting element. For example, ITO of 300 Ω/□ or less can function as the first electrode, but since it is now possible to supply ITO of about 10 Ω/□, it is more preferable to use a low resistance product. The thickness of the first electrode can be selected arbitrarily according to characteristics such as transmittance and resistance value, but can usually be between 100 nm and 300 nm.

The first electrode can be formed by a known method. For example, after forming a film by a vacuum film forming method such as sputtering, it can be patterned by etching using a photoresist.

<Pixel division layer>
In the organic EL display device of the present invention, the pixel division layer has a pixel opening 3, a pixel division portion 4, and a dam portion 5. That is, the pixel division layer must be patterned, and the pixel opening portion, which is the removed portion, functions as a display pixel. Therefore, the pixel division layer is required to be insulating, and is not limited to either an organic or inorganic material, but it is preferable to include a cured film of a photosensitive resin composition from the viewpoint of processability. In addition, it is important to process the first electrode of the pixel opening so that there is no foreign matter or residue, since this may directly lead to defects in the display device, such as short circuits and black spots.

<Pixel division section>
As described above, since a display pixel is formed by forming the pixel opening 3 on the first electrode 2, the display pixel can be arbitrarily designed using the pixel dividing section 4. Specifically, by patterning a pixel dividing portion in the gap of the first electrode, the exposed portion of the first electrode is limited, and only the pixel opening functions as a display pixel. Furthermore, by covering the periphery of the line-type or island-type first electrode with the pixel dividing portion, it also helps prevent short circuits that occur at the edge of the first electrode and disconnection of the second electrode, increasing the reliability of the display device. can be improved.

Further, the boundary between the pixel opening and the pixel division section may also cause disconnection of the second electrode depending on the shape, so it is preferable that the boundary has a gently tapered shape. Here, the forward tapered shape refers to the angle formed by the tangent at the interface between the first electrode and the pixel division part and the tangent at the position of the film thickness of 50% of the maximum thickness of the pixel division part on the surface of the tapered part of the pixel division part (hereinafter referred to as , this angle may be referred to as the taper angle of the pixel dividing section) is less than 90°. In the present invention, in order to obtain a highly reliable display device in which disconnection of the second electrode is suppressed, the taper angle of the pixel dividing portion is preferably less than 60°, more preferably less than 50°.

The taper angle of the pixel dividing section will be specifically explained using FIG. 3. In FIG. 3, a first electrode 2 is provided on a base material 1. A pixel dividing section 3 is provided in the gap between the first electrode 2. The angle G formed by the tangent at the interface between the first electrode and the pixel dividing part and the tangent at the position (point F) of the film thickness of 50% of the maximum thickness of the pixel dividing part on the surface of the tapered part of the pixel dividing part is Defined as the taper angle of the split part.

The pixel dividing portion is not limited to known organic or inorganic materials, but photosensitive resin containing an alkali-soluble resin is used because of its workability and shape, as well as ease of adjusting surface roughness as described below. It is preferable to include a cured film of the composition. The pixel dividing section may be a single layer or a multilayer. For example, if the pixel dividing section is a multilayer, the surface approximately parallel to the base material whose surface roughness is to be measured is a photosensitive resin containing an alkali-soluble resin. Preferably, it is a cured film of a resin composition.

The photosensitive resin composition preferably contains (A) an alkali-soluble resin, (B) a photosensitizer, and (C) an organic solvent, and may further contain (D) a coloring material and (E) a liquid-repellent material. By incorporating (A) an alkali-soluble resin and (B) a photosensitizer in combination as a photosensitive resin composition, pattern processing using photosensitivity becomes possible. In addition, by incorporating (C) an organic solvent, it is possible to make the composition in a varnish state, which may improve the coatability. Furthermore, by incorporating (D) a coloring material in the photosensitive resin composition, it is possible to blacken the pixel division portion. In addition, by incorporating (E) a liquid-repellent material, it is possible to impart liquid repellency to the pixel division portion. The photosensitive resin composition may further contain other components.

The pixel division section can be formed by any known method. Among them, the wet coating method is preferred because it can form a thin film uniformly on a large substrate. Examples of wet coating methods include spin coating, slit coating, dip coating, spray coating, and printing. The thickness of the pixel division section is usually 0.3 μm to 10 μm, but is not particularly limited as long as it is sufficient to cover the irregularities of the first electrode.

<Dam Section>
In the organic EL display device of the present invention, the pixel division layer has a dam portion 5. The dam portion needs to be provided in order to suppress a problem called crosstalk, which is a light emission defect caused by a leakage current between adjacent display pixels. Since a leakage current is a phenomenon that occurs between the first electrodes of two adjacent display pixels, in the present invention, the uneven structure existing between the adjacent display pixels is defined as the dam portion. Specifically, when two display pixels, a certain display pixel and its closest display pixel, are extracted, the uneven structure other than the pixel division portion existing on the center line between them is called the dam portion.

In the present invention, it is preferable that the dam portion has a convex structure. 4 and 5 show schematic cross-sectional views of a dam portion having a convex structure, which is an example of the present invention. In addition, as another embodiment, it is also preferable that the dam portion has a concave structure. 6 and 7 show schematic cross-sectional views of a dam portion having a concave structure, which is an example of the present invention. Since leakage current occurs through a highly mobile material contained in the organic EL layer, specifically, through a metal-doped layer, it is important to divide or thin the metal-doped layer that serves as the path by the dam portion. In addition, since the leakage current to be suppressed in the present invention occurs between the first electrodes, when there are multiple metal-doped layers in the organic EL layer, it is important to divide or thin the metal-doped layer closest to the first electrode. The metal-doped layer may be either a single layer or multiple layers, and the alkali metal-doped layer and/or rare earth metal-doped layer closest to the first electrode is called the metal-doped layer K. A schematic cross-sectional view of the first electrode 2, pixel opening 3, pixel division portion 4, dam portion 5, and metal-doped layer K is shown in FIG. 8.

As one specific method for dividing the metal doped layer K, it is preferable that the taper angle of the dam portion exceeds 90° (hereinafter sometimes referred to as a "reverse taper shape"). Specifically, FIG. 9 shows an example in which the taper angle of the dam part having a convex structure is a reverse taper shape, and FIG. 10 shows an example in which the taper angle of the dam part having a concave structure is a reverse taper shape. Although increasing the angle increases the reliability of separation, if the angle is too large, the shape becomes unstable or becomes a starting point for peeling, leading to a decrease in bending reliability. It is more preferable that the angle be 91 to 120 degrees from the viewpoint of the dividing effect and the ease of machining the dam part. Here, the inverted tapered shape refers to the angle formed by the tangent between the surface of the pixel division section that is substantially parallel to the base material and the surface of the tapered section of the dam section at a position (point H) at 50% of the maximum height of the dam section. J (hereinafter, this angle may be referred to as "the taper angle of the dam part") refers to a state in which it exceeds 90°. With such a reverse tapered shape, the tapered portion becomes a shadow when forming the metal doped layer, and it is possible to prevent the metal doped layer K from being formed on the tapered portion. As a result, the path of the leakage current can be completely separated and the leakage current can be suppressed, which is preferable.

Further, as one specific method for thinning the metal doped layer K, it is preferable that the taper angle of the dam portion is 90° or less (hereinafter sometimes referred to as "forward taper shape"). As in the case of the reverse tapered shape, FIG. 11 shows an example in which the taper angle of the dam part with a convex structure is a forward taper shape, and FIG. 12 shows an example in which the taper angle of the dam part with a concave structure is a forward taper shape. By forming such a forward tapered shape, the metal doped layer K formed on the tapered surface of the dam portion can be made thinner than on a surface substantially parallel to the base material. Specifically, it is preferable that the film thickness of the tapered surface of the dam part be 0.5 times or less the film thickness of the pixel dividing part, since leakage current can be sufficiently suppressed. However, if the metal doped layer K is not formed even partially, the adhesion in the organic EL layer will deteriorate. Therefore, also on the tapered surface of the dam part, it is preferable that the thickness of the metal doped layer K is 0.5 nm or more. The film thickness L of the metal doped layer K at the pixel division part and the film thickness M at the tapered surface of the dam part are measured in the direction perpendicular to the surface, and are schematically shown in FIG. For the purpose of controlling the workability of the dam part and the thickness of the metal doped layer K, it is more preferable that the taper angle of the dam part is 50 to 90 degrees. If the taper angle of the dam part is smaller than 50°, the metal doped layer K cannot be made sufficiently thin, and the effect of suppressing crosstalk becomes small.

Since the dam part is included in the pixel dividing layer, it is not limited to any known organic or inorganic material like the pixel dividing part, but it is easy to adjust the surface roughness described below in addition to the processability and shape. From this point of view, it is preferable to include a cured film of a photosensitive resin composition containing an alkali-soluble resin. The dam part may be a single layer or a multilayer. For example, if the dam part is a multilayer, the surface substantially parallel to the base material whose surface roughness is to be measured is a photosensitive resin containing an alkali-soluble resin. Preferably, it is a cured film of a resin composition. Furthermore, in the case of a convex structure, a base film for the dam part may be formed at the same time as the pixel division part, and a convex structure may be formed on top of the base film. In the case of a concave structure, the film may be formed at the same time as the pixel dividing portion, and then only the dam portion may be removed. Furthermore, when using a photosensitive resin composition different from that of the pixel dividing part, the cured film may be formed again after removing the base material and the first electrode in the dam part until they are exposed. In any case, since it is sufficient to finally obtain the desired shape of the dam portion, a known film forming method such as coating or printing, or a removal method such as etching or cutting may be appropriately set.

The level difference in the dam part is managed by the absolute value of the film thickness difference with respect to the pixel division part, which is the reference for the level difference. The size of the step is not particularly limited, but if it is a convex structure, it is usually 0.5 μm to 3.0 μm, and if it is a concave structure, it is usually 0.2 μm to 2.0 μm, which is less than the film thickness of the pixel division part. For the purpose of dividing or thinning the metal doped layer, the thickness is set to at least 0.1 μm or more.

<Surface roughness of pixel division section and dam section>
In the present invention, the surface roughness (Ra1) of the pixel division portion is preferably 0.1 nm or more and 20 nm or less. Also, the surface roughness (Ra2) of the top surface of the dam portion having a convex structure and/or the bottom surface of the dam portion having a concave structure is preferably 1 nm or more and 50 nm or less.

Conventionally, poor adhesion between the pixel division layer and the organic EL layer has led to easy peeling, which has been a major problem in terms of bending reliability, especially in flexible products. In the present invention, by controlling the surface roughness of the pixel division part and the dam part included in the pixel division layer, an anchor effect can be obtained and the adhesion with the organic EL layer can be improved. An anchor effect can be obtained if the surface roughness (Ra1) of the pixel dividing portion close to the display pixel is 0.1 nm or more, but it is preferably 20 nm or less for the purpose of suppressing defects in the display pixels. In order to achieve both anchoring effect and defect suppression, it is more preferable that Ra1 is 5 to 15 nm. Further, the surface roughness (Ra2) of the dam portion is preferably 5 nm or more from the viewpoint of freedom of processing, and a sufficient anchor effect can be obtained. Further, for the purpose of suppressing defects in post-processes such as the second electrode and sealing, the thickness is preferably 50 nm or less. In order to achieve both anchoring effect and defect suppression, it is more preferable that Ra2 is 20 to 40 nm. Furthermore, when the absolute value of the difference between Ra1 and Ra2 is 1.0 nm or more, two types of anchor effects can be obtained, which is more preferable from the viewpoint of improving adhesion. In the present invention, for the purpose of adjusting the surface roughness of the pixel dividing part and the dam part, it is preferable that the pixel dividing layer contains silica particles having a primary particle diameter of 5 to 30 nm, which will be described later.

The atomic force microscope (AFM) used to measure surface roughness in the present invention generally measures the substrate of an organic EL display device placed on a horizontal surface from vertically above, so the target ranges of Ra1 and Ra2 are as shown in Figures 13 and 14. That is, in the present invention, the surface roughness of the pixel division section and the dam section refers to the surface that is in contact with the organic EL layer and can be measured by AFM, that is, the surface roughness of the surface that is approximately parallel to the substrate excluding the tapered portion.

<(A) Alkali-soluble resin>
In the present invention, alkali-soluble means that a solution of the resin dissolved in γ-butyrolactone (GBL) is applied onto a silicon wafer and prebaked at 120°C for 4 minutes to form a prebaked film with a thickness of 10 μm ± 0.5 μm. , the dissolution rate determined from the decrease in film thickness when the prebaked film is immersed in a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 23°C ± 1°C for 1 minute and then rinsed with pure water is 50 nm/min or more. It means that.

(A) The alkali-soluble resin preferably has an aromatic carboxylic acid structure in order to improve heat resistance. In the present invention, an aromatic carboxylic acid structure refers to a carboxylic acid structure that is directly covalently bonded to an aromatic ring.

(A) The alkali-soluble resin is one or more selected from the group consisting of acrylic resin, phenol resin, polysiloxane resin, cardo resin, polyimide resin, polyimide precursor resin, polybenzoxazole resin, and polybenzoxazole precursor resin. It is preferable to contain resin. Among these resins, (A) alkali-soluble resin is selected from the group consisting of polyimide resin, polyimide precursor resin, polybenzoxazole resin, and polybenzoxazole precursor resin in terms of achieving both heat resistance and chemical resistance. It is more preferable to contain at least one type of resin. High chemical resistance is preferable because it reduces film loss when processing the pixel division layer by wet etching. In addition, polyimide precursor resin is more preferable because it produces less outgassing under high-temperature conditions. From the viewpoint of improving alkali solubility, polyimide precursor resins having an amic acid structure are particularly preferred.

<Silica Particles in Pixel Dividing Layer>
The pixel division layer in the organic EL display device of the present invention preferably contains (a) silica particles having a primary particle diameter of 5 nm to 30 nm (hereinafter, sometimes referred to as (a) component). It is more preferable that the pixel division layer further contains a coloring material (D) described later in addition to the (a) component, and in such a case, it is more preferable that the (D) coloring material contains an organic pigment (D1) described later, and it is even more preferable that the (D1) organic pigment contains a component (b) described later. As described later, the (a) component has a primary particle diameter of 5 nm to 30 nm and an aspect ratio (major axis/minor axis) of 1.0 to 1.5. By containing the (a) component, it is possible to adjust the surface roughness of the pixel division section and the dam section, and to increase the uniformity of the opening width of the opening to reduce brightness unevenness. The primary particle diameter referred to here means the major axis of the particle, and the silica particles having a primary particle diameter of 5 nm to 30 nm refer to those having a primary particle diameter in the range of 5 nm to 30 nm. The "aspect ratio (major axis/minor axis)" referred to here means the value obtained by dividing the major axis by the minor axis of the primary particle diameter of the silica particles and rounding the value to one decimal place.

The silica particles herein refer to particles with a SiO ₂ content of 90% or more by weight excluding water, particles made of silicon dioxide (anhydrous silicic acid), and particles made of silicon dioxide hydrate (hydrated silicic acid). and particles made of quartz glass. The form in which hydrous silicic acid exists is not particularly limited, and particles made of orthosilicic acid, metasilicic acid, and/or metadisilicic acid also correspond to the silica particles referred to herein. The weight excluding water means the weight obtained by subtracting the weight of water in the particles from the weight of the particles.

However, in core-shell type composite particles, particles that do not contain SiO ₂ as a core, for example particles made of organic polymers, or surface treatment agents and coatings applied as a shell to at least a part of the surface of organic pigments or inorganic pigments. Even if the layer contains SiO ₂ , it is defined that the layer alone does not correspond to silica particles, regardless of the content of SiO ₂ . On the other hand, core-shell composite particles that contain SiO ₂ in the core and have an SiO ₂ content of 90% by weight or more excluding water are defined as silica particles. That is, the component (a) is filled as particles in a dispersed form in the pixel division layer. The particle structure of component (a) is not particularly limited, and may have internal voids.

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 silica particles made of a composite oxide of silicon and metal, in which the _SiO2 content is 90% by weight or more, excluding water. Examples of metals mentioned here include zirconium, titanium, and cerium. However, silica particles containing hafnium atoms are defined as a mixture of silica particles and hafnium atoms (hereinafter, sometimes referred to as component (c)).

In order to further reduce uneven brightness of an organic EL display device, component (a) is preferably silica particles with a primary particle size of 5 nm to 20 nm, and even more preferably 5 nm to 15 nm. The primary particle diameter here refers to the major axis of the silica particles. It is more preferable to contain silica particles with an aspect ratio of 1.0 to 1.3, and even more preferable to contain silica particles with an aspect ratio of 1.0 to 1.2. Note that when the aspect ratio is 1.0, it can be considered as a truly spherical silica particle.

Component (a) and silica particles other than component (a) are prepared by cutting the pixel dividing layer into thin slices as an observation sample, and polishing them by pretreatment, preferably by ion milling, and more preferably by focused ion beam (FIB) processing. Evaluate the cross section with improved smoothness. Specifically, a portion located within a range of 0.2 μm to 0.8 μm in the film depth direction from the outermost layer of the pixel division layer was analyzed using a transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX). By doing so, the elements constituting the particles can be determined and specified from the element mapping information. Transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS) or scanning transmission electron microscopy-energy dispersive x-ray spectroscopy (STEM-EDX) can also be used for analysis.

More specifically, a sample was observed using a transmission electron microscope-energy dispersive ” (manufactured by MOUNTECH). In this way, it is possible to distinguish between silica particles that fall under component (a) and silica particles that do not fall under component (a). That is, 30 silica particles on the TEM image were randomly selected in the cross section of the pixel division layer, and the major axis, minor axis, and aspect ratio on the TEM image were measured for each, and the major axis (nm) was 5 nm to 30 nm. Silica particles having an aspect ratio of 1.0 to 1.5 are defined as component (a). In addition, when the short axis and long axis of one silica particle in TEM imaging are equal, that is, when it is a perfect circle, the diameter is regarded as the long axis. Typical values that indicate the characteristics of silica particles corresponding to component (a) are the average value of the primary particle diameter, that is, the average value of the major diameters rounded to the first decimal place, and the average value of the aspect ratio. The value, that is, the average value of the aspect ratios of individual silica particles corresponding to component (a) is calculated, and the value rounded to the second decimal place is used. Here, the analysis is performed excluding SiO ₂ that has a contact point with the surface of particles such as polymer particles, organic pigments, and/or inorganic pigments.

In addition, the pixel dividing layer included in the organic EL display device of the present invention further contains silica particles that do not fall under component (a), that is, silica particles having a primary particle diameter of less than 5 nm or more than 30 nm, /breadth) may contain silica particles exceeding 1.5. Examples of silica particles that do not fall under component (a) include "Adomafine" (registered trademark) SO-E2, SO-E4 (both manufactured by Admatec), KE-P10, KE-S10 (all of the above). (manufactured by Nippon Shokubai Co., Ltd.).

The pixel division layer of the organic EL display device of the present invention may further contain particles that contain _SiO2 at a content rate of less than 90% by weight, excluding water, and 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 is an organic-inorganic composite particle with a silica:polymer ratio of 70:30 by weight.

The average primary particle diameter of the silica particles contained in the pixel division layer of the organic EL display device of the present invention is preferably 5 nm to 30 nm, more preferably 5 nm to 25 nm, from the viewpoint of suppressing uneven brightness. 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 division layer of the organic EL display device of the present invention contains silica particles that do not fall under the (a) component, it is preferable that the average primary particle diameter of all the contained silica particles is 5 nm to 30 nm. Similarly, it is preferable that the average aspect ratio (major axis/minor axis) is 1.0 to 1.3. The silica particles referred to here include both the (a) component and silica particles that do not fall under the (a) component. The average primary particle diameter referred to here can be obtained by the same method as the observation of the (a) component described above. Specifically, the cross section of the pixel division layer located in the range of 0.2 μm to 0.8 μm in the film depth direction from the outermost layer is observed under the condition of 50,000 times magnification by transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX), and the measurement is performed using an image analysis type particle size distribution measuring instrument (Mac-View, manufactured by MOUNTECH). Thirty silica particles are randomly selected from the TEM image, and the average value of the major axis of all the silica particles is rounded off to the nearest tenth. Furthermore, the "average aspect ratio (major axis/minor axis)" as used herein refers to the average value obtained by dividing the major axis by the minor axis for each of the primary particles of all the silica particles randomly obtained from the same image, and rounding off to the nearest tenth. Silica particles with an average primary particle size of 5 nm to 30 nm refer to particles with an average primary particle size in the range of 5 to 30 nm, and silica particles with an average aspect ratio of 1.0 to 1.3 refer to particles with an average aspect ratio in the range of 1.0 to 1.3.

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

Examples of functional groups that component (a) 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. In particular, in order to further reduce unevenness in brightness, it is preferable to have reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups. The reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups referred to here mean 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 preferable that component (a) contains silica particles having reactive residues of surface-modifying groups containing ethylenically unsaturated double bond groups on the particle surface, and the reactive residues of the surface-modifying groups containing ethylenically unsaturated double bond groups have a structure represented by formula (1) and/or a structure represented by formula (2). 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.

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

In formula (2), R ₂₀ represents a hydrogen atom or a methyl group. R ₂₁ represents an oxyalkylene group having 1 to 3 carbon atoms. r is an integer representing 1 to 4. * ³ represents a bonding site with a carbon atom. * ⁴ represents a bonding site with an oxygen atom bonded to a silicon atom, which the silica particle has on the particle surface.

The component (a) having the structure represented by formula (1) 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.

Examples of organic alkoxysilane compounds having an ethylenically unsaturated double bond group include vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, and 3-methacryloxypropylmethyldimethoxy. Silane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3 -Acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, allyltrimethoxysilane, and allyltriethoxysilane.

The component (a) whose reactive residue has a structure represented by formula (2) 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 isocyanate compounds having an ethylenically unsaturated double bond group include 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-(2-methacryloyloxyethyloxy)ethyl isocyanate.

In addition, 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 (a) whose reactive residues have a structure represented by formula (1) and a structure represented by formula (2).

For example, in order to improve the dispersion stability of component (a) in a negative photosensitive composition, component (a) preferably has a trialkylsilyl group, more preferably a trimethylsilyl group. preferable. The trimethylsilyl group can be introduced into the component (a) by converting the hydrogen atoms in the surface silanol groups of the silica particles into trimethylsilyl groups using a trimethylsilylating agent. Examples of the trimethylsilylation agent include hexamethyldisilazane and trimethylalkoxysilane, which can be introduced by deammonia reaction and dehydration condensation reaction, respectively. By improving the dispersion stability of component (a), it may be possible to more stably reduce brightness unevenness.

In order to further reduce unevenness in brightness, component (a) preferably contains silica particles having sodium atoms. Existing forms of sodium atoms include, for example, ions (Na+) and salts with silanol groups (Si-ONa). The content of sodium atoms in component (a) is preferably 100 to 5,000 ppm by weight. Silica particles having sodium atoms can be synthesized by reacting sodium silicate, which is a strong alkaline silicon source, with a mineral acid, which is a strong acid, under alkaline conditions. Note that the sodium atoms possessed by the silica particles can be detected at the central portion corresponding to the intersection of the long axis and the short axis when imaging the cross section of the primary particle using the above-mentioned TEM-EDX.

The content of component (a) in the pixel dividing layer is preferably 1 to 50% by weight, and more preferably 5 to 20% by weight in terms of SiO ₂ in order to suppress unevenness in brightness. From the same point of view, all silica components in the pixel dividing layer are preferably 1 to 50% by weight, more preferably 7 to 30% by weight in terms of SiO ₂ . The content in terms of SiO ₂ here means the content calculated by excluding the weight of water in the silica particles, which varies depending on the thermal history, based on the technical common knowledge of those skilled in the art.

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

Examples of inorganic particles containing component (c) include hafnium oxide (HfO ₂ ), a composite oxide of hafnium and a metal other than hafnium, a solid solution of an oxide of a metal other than hafnium and hafnium oxide, hafnium oxynitride, a composite oxynitride of hafnium and a metal other than hafnium, and a solid solution of an oxynitride of a metal other than hafnium and hafnium oxynitride. Among these, hafnium oxide (HfO ₂ ) or a composite oxide of hafnium and a metal other than hafnium is preferred from the viewpoint of excellent effect of reducing unevenness in brightness, and a composite oxide of zirconium and hafnium (ZrO ₂ -HfO ₂ ) is more preferred.

As the inorganic particles containing component (c), commercially available products in powder form can be used, such as Hafnium oxide P, Hafnium oxide R, and Hafnium S (all manufactured by ATI METALS), hafnium oxide fine particles. (manufactured by Kojundo Kagaku Kenkyusho Co., Ltd.). Another method is to wet-polish the surface of a grinding media containing component (c) using mechanical energy in the process of preparing a pigment dispersion containing component (b), which will be described later. By codispersing them, the component (c) may be included in the finally obtained pixel division layer.

The content of component (c) can be quantified by ICP (inductively coupled plasma) emission spectrometry using a solution obtained by cutting out a portion of the pixel division layer located 0.2 μm to 0.8 μm deep from the outermost layer, heating and incinerating it at a temperature of 800°C or higher in an electric furnace, decomposing it by heating with sulfuric acid, nitric acid, and hydrofluoric acid, and then dissolving it by heating with dilute nitric acid as an analytical sample. A PS3520VDDII (manufactured by Hitachi High-Tech Science Corporation) can be used as the analytical device.

<(D) Coloring material>
When coloring of the pixel division layer is required from the viewpoint of light-shielding property and anti-reflection, it is preferable that the photosensitive resin composition used in the pixel division layer in the present invention contains a (D) coloring material. By containing the (D) coloring material in the photosensitive resin composition, the pixel division layer contains the (D) coloring material, and each effect described later can be obtained, which is preferable. The (D) coloring material is a compound that absorbs light of a specific wavelength, and in particular, refers to a compound that is colored by absorbing light of a wavelength of visible light (380 nm to 780 nm). By containing the (D) coloring material, it is possible to color the cured film obtained from the photosensitive resin composition, and it is possible to impart coloring properties that color the light transmitted through the cured film of the photosensitive resin composition or the light reflected from the cured film of the photosensitive resin composition to a desired color. In addition, it is possible to impart light-shielding properties that block light of a wavelength absorbed by the (D) coloring material from the light transmitted through the cured film of the photosensitive resin composition or the light reflected from the cured film of the photosensitive resin composition.

The content of the coloring material (D) used in the present invention is preferably 1% by weight or more, more preferably 10% by weight or more, and even more preferably 15% by weight or more in the pixel dividing layer. When the content ratio is within the above range, light-shielding properties, coloring properties, or toning properties can be improved. On the other hand, the content ratio is preferably 70% by weight or less, more preferably 65% by weight or less, and even more preferably 60% by weight or less. When the content ratio is within the above range, sensitivity during exposure can be improved.

(D) Coloring materials include (D1) organic pigments, (D2) inorganic pigments, and (D3) dyes that absorb visible light wavelengths and color white, red, orange, yellow, green, blue, or purple. Examples include known compounds such as. Two or more of these coloring materials may be used in combination, or two or more colors may be used in combination. A combination of two or more types is preferable because the resulting pixel division layer has the effects described later. By combining two or more colors, the color toning ability is improved by toning the light that passes through the cured film of the photosensitive resin composition or the light that is reflected from the cured film of the photosensitive resin composition to the desired color coordinates. can be done.

By using the (D1) organic pigment as the (D) coloring material, the (D1) organic pigment's characteristic chemical structure change or functional group conversion function allows it to transmit or block light of a specific wavelength, thereby adjusting the transmission spectrum or absorption spectrum of the cured film of the photosensitive resin composition and improving color tuning. Details of such (D1) organic pigments will be described later.

(D) By applying the (D2) inorganic pigment as a coloring material, the heat resistance and weather resistance of the cured film of the photosensitive resin composition are Weather resistance can be improved. (D2) Inorganic pigments include, for example, zirconium nitride, zirconium oxide, titanium oxide, barium carbonate, zinc white, zinc sulfide, white lead, calcium carbonate, barium sulfate, white carbon, alumina white, silicon dioxide, kaolin clay, and talc. , bentonite, red iron, molybdenum red, molybdenum orange, chrome vermilion, chlorine, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, navy blue , cobalt blue, cerulean blue, cobalt silica blue, cobalt zinc silica blue, manganese violet, cobalt violet, graphite or silver-tin alloy, or titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium or silver, etc. Examples include fine metal particles, oxides, composite oxides, sulfides, sulfates, nitrates, carbonates, nitrides, carbides, and oxynitrides.

Among these, in order to set the surface roughness of the pixel division portion to 0.1 nm or more and 20 nm or less, it is preferable to disperse an inorganic pigment with a large specific gravity such as zirconium nitride. Inorganic pigments have problems such as pigment aggregation, thickening, and sensitivity reduction over time, but by setting the acid equivalent of component (A) to 200 g/mol or more and 500 g/mol or less, the alkali solubility can be adjusted favorably. If the acid equivalent of component (A) is less than 200 g/mol, for example, when obtaining a cured film of a positive photosensitive resin composition, the alkali solubility of the unexposed part becomes high, and the difference in dissolution rate with the exposed part is small, making it impossible to form a desired pattern. By setting the acid equivalent to 200 g/mol or more, the solubility of the unexposed part can be suppressed, and a pattern with less residue at the opening due to adhesion of eluted matter from the unexposed part can be formed. In addition, by setting the acid equivalent of component (A) to 500 g/mol or less, the dispersion stabilization of zirconium nitride particles can be promoted, and a photosensitive resin composition with excellent storage stability can be obtained.

(D3) Dyes are compounds that color an object by chemically adsorbing or strongly interacting with the surface structure of the object through substituents such as ionic groups or hydroxyl groups in the dye, and are generally soluble in solvents. In addition, dyes have high coloring power and high color development efficiency because each molecule is adsorbed to the object. Dyes can be classified into, for example, direct dyes, reactive dyes, sulfur dyes, vat dyes, sulfur dyes, acid dyes, metal-containing dyes, metal-containing acid dyes, basic dyes, mordant dyes, acid mordant dyes, disperse dyes, cationic dyes, and fluorescent whitening dyes. In terms of materials, examples of the dyes include anthraquinone dyes, azo dyes, azine dyes, phthalocyanine dyes, methine dyes, oxazine dyes, quinoline dyes, indigo dyes, indigoid dyes, carbonium dyes, threne dyes, perinone dyes, perylene dyes, triarylmethane dyes, and xanthene dyes. From the viewpoint of (C) solubility in organic solvents and heat resistance, anthraquinone dyes, azo dyes, azine dyes, methine dyes, triarylmethane dyes, and xanthene dyes are preferred.

Among these, in order to set the surface roughness of the pixel division portion to 0.1 nm or more and 20 nm or less, it is preferable to contain (D3-1) a salt-forming compound consisting of an acid dye and a basic dye as the coloring material (D). This is because by containing (D3-1) a salt-forming compound consisting of an acid dye and a basic dye, dye precipitation during development is expected.

(D3-1) A salt-forming compound consisting of an acidic dye and a basic dye is a compound obtained by reacting an acidic dye and a basic dye. It is a chemically stable compound obtained by a chemical (salt formation) reaction between an acidic dye whose dye ions are anionic and a basic dye whose dye ions are cationic.

An acid dye is a compound having an acidic substituent such as a sulfo group or a carboxy group in the dye molecule, or an anionic water-soluble dye that is a salt thereof. Note that acid dyes include those that have an acidic substituent such as a sulfo group or a carboxy group and are classified as direct dyes. Among them, it is preferable that the acid dye contains a xanthene acid dye, since it can reduce the amount of residue at the opening. It is more preferable that the xanthene acid dye contains a rhodamine acid dye such as C.I. Acid Red 50, 52, or 289, since it can further reduce the amount of residue at the opening. It is even more preferable that the rhodamine acid dye contains C.I. Acid Red 52, since it can increase the blackness of the cured film.

A basic dye is a compound having a basic group such as an amino group or an imino group in the molecule, or a salt thereof, and is a dye that becomes a cation in an aqueous solution. Among them, the basic dye preferably contains a triarylmethane-based basic dye, since it can increase the blackness of the cured film. It is more preferable that the triarylmethane-based basic dye contains C.I. Basic Blue 7 and/or C.I. Basic Blue 26, since it can increase the blackness of the cured film.

A salt-forming compound of an acidic dye and a basic dye can be synthesized by a known method. For example, when an aqueous solution of an acidic dye and an aqueous solution of a basic dye are respectively prepared and mixed slowly while stirring, a salt-forming compound of the acidic dye and the basic dye is produced as a precipitate. By collecting this by filtration, the salt-forming compound can be obtained. The obtained salt-forming compound is preferably dried at about 60 to 70°C.

Furthermore, by setting the content of the salt-forming compound in the photosensitive resin composition to 10 parts by weight or more per 100 parts by weight of the alkali-soluble resin (A), blackening can be achieved, and by setting it to 75 parts by weight or less, the amount of residue in the opening can be reduced. By including the salt-forming compound in this range, the alkali solubility of the exposed and unexposed areas can be favorably adjusted.

Furthermore, when it is desired to increase the blackness of the cured film, it is preferable to contain (D3-2) a nonionic dye as the (D) coloring material.

(D3-2) Nonionic dyes are dyes other than acidic dyes and basic dyes and do not have an ionic structure.

Examples of nonionic dyes include C.I. I. Disperse Orange 5;C. I. Dispersed Red 58; C. I. Disperse Blue 165; C. I. Azo nonionic dyes such as Solvent Red 18; C.I. I. Bat Blue 4;C. I. Dispersed thread 22, 60; C. I. Disperse Violet 26, 28, 31; C. I. Disperse Blue 14, 56, 60; C. I. Solvent Violet 13, 31, 36; C.I. I. Examples include anthraquinone nonionic dyes such as Solvent Blue 35, 36, 45, 63, 78, 87, 97, 104, and 122.

Among these, as the nonionic dye, anthraquinone nonionic dyes are preferable because they can increase the degree of blackness of the cured film.

<(D1) Organic Pigment>
Examples of the organic pigment (D1) used as the coloring material (D) include phthalocyanine pigments, anthraquinone pigments, quinacridone pigments, pyranthrone pigments, dioxazine pigments, thioindigo pigments, diketopyrrolopyrrole pigments, quinophthalone pigments, threne pigments, indoline pigments, isoindoline pigments, isoindolinone pigments, benzofuranone pigments, perylene pigments, aniline pigments, azo pigments, azomethine pigments, condensed azo pigments, carbon black, metal complex pigments, lake pigments, toner pigments, and fluorescent pigments. From the viewpoint of heat resistance, anthraquinone pigments, quinacridone pigments, pyranthrone pigments, diketopyrrolopyrrole pigments, benzofuranone pigments, perylene pigments, condensed azo pigments, and carbon black are preferred.

In the present invention, it is preferable that the photosensitive resin composition used to form the pixel dividing layer contains an organic pigment, for the effect of imparting light-shielding properties to the pixel dividing layer. When the photosensitive resin composition contains an organic pigment, the pixel division layer contains the organic pigment, which is preferable because each effect described below can be obtained. In such a case, it is preferable to further contain an organic black pigment and/or a mixed color organic black pigment (hereinafter sometimes referred to as component (b)) as the organic pigment (D1).

Organic black pigments include benzodifuranone-based black pigments, perylene-based black pigments, and azomethine-based black pigments.

Benzodifuranone-based black pigments include, for example, the pigments disclosed in International Publication No. 2009/010521. As commercially available benzodifuranone-based black pigments made of a compound represented by formula (5) described below, "Irgaphor" (registered trademark) Black S0100CF and Experimental Black 582 (both manufactured by BASF) can be preferably used.

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).

Examples of azomethine-based black pigments include the pigments disclosed in US Patent Application Publication No. 2002-121228. As a commercially available product, Chromofine Black A1103 (manufactured by Dainichiseika Kagyo Co., Ltd.) can be used.

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

Examples of organic yellow pigments include C.I. I. Pigment Yellow 24, 120, 138, 139, 151, 175, 180, 185, 181, 192, 193, 194. Examples of organic orange pigments include C.I. 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. 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.

Among the components corresponding to component (b) above, the component (b) contained in the pixel dividing layer in the organic EL display device of the present invention contains an organic black pigment and is suitable for reducing unevenness in brightness. It is preferable that the organic black pigment contains a compound represented by formula (3) or formula (4) and/or an isomer thereof. The component (b) contained in the pixel dividing layer more preferably contains a compound represented by formula (5) or an isomer thereof. The compounds represented by formulas (3) to (5) can be synthesized by reacting 2,5-dihydroxy-1,4-benzenediacetic acid with isatin or a derivative thereof under an acidic catalyst, and then converted into a pigment. You can get it at

In formulas (3) and (4), R ₂₂ to R ₃₁ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

In order to further suppress unevenness in brightness, the component corresponding to component (b) may be subjected to micronization treatment using a known method such as a solvent salt milling method or an acid paste method. When making a benzodifuranone black pigment fine, brightness unevenness may be easily suppressed by allowing the compound represented by formula (6) or its salt to coexist and adsorbing it to the pigment surface.

In formula (6), n and m represent integers and are each independently an integer of 0 to 2.
However, n+m≧1 is satisfied.

Further, when the component (b) contains a benzodifuranone black pigment, it is preferable to have a coating layer containing silica on the surface of the pigment in order to improve developability and suppress development residues in the openings. The silica contained in the coating layer herein is not the component (a) mentioned above, but is a part of the component (b).

The content of component (b) in the pixel division layer is preferably 1% by weight or more, more preferably 10% by weight or more, in order to achieve high light blocking properties. In order to reduce unevenness in brightness, the content is preferably 50% by weight or less, more preferably 30% by weight or less.

Furthermore, when the component (a) is further contained in addition to the component (b), the content of the component (a) relative to 100 parts by weight of the component (b) is preferably 20 to 70 parts by weight, more preferably 30 to 50 parts by weight, calculated as _SiO2 , in order to reduce luminance unevenness. That is, in the organic EL display device of the present invention, the content of the component (a) relative to the component (b) in the pixel dividing layer is preferably 20 to 70 parts by weight, calculated as _SiO2 .

<(E) Liquid-repellent material>
When the organic EL layer is formed by the inkjet method, it is preferable that the photosensitive resin composition used in the pixel division layer of the present invention contains a liquid-repellent material. Although known materials such as fluorine-based polymers and fluorine-containing compounds having silane compounds can be used, a liquid-repellent material having at least an amide group or a urethane group is preferable. By having an amide group or a urethane group, the compatibility with the above-mentioned alkali-soluble resin (A) is improved, defects such as repelling are reduced, and the film thickness uniformity of the cured film is improved, and as a result, display defects of the display device are reduced.

Examples of liquid-repellent materials include 2-(perfluorobutyl)ethyl (meth)acrylate and 2-(perfluorohexyl)ethyl (meth)acrylate, which are (meth)acrylate monomers having a perfluoroalkyl group, as commercially available products. , "Mega Fac" (registered trademark) RS-72-K, RS-72-A, RS-75, RS-76-E, RS-76-NS, RS-78, RS-90 (manufactured by DIC Corporation) ) etc.

Preferred examples of epoxy group-containing (meth)acrylate monomers include glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether (4-HBAGE), 4-hydroxybutyl methacrylate glycidyl ether, and alicyclic epoxy groups. Examples include acrylates having an alicyclic epoxy group, and metharylates having an alicyclic epoxy group.

<Organic EL Layer>
In the organic EL display device of the present invention, the configuration of the organic EL layer 6 is not particularly limited, and may be, for example, any of (1) hole transport layer/light emitting layer, (2) hole transport layer/light emitting layer/electron transport layer, and (3) light emitting layer/electron transport layer. Furthermore, a tandem type in which a plurality of the above configurations are laminated via a charge generating layer may be used. The charge generating layer is generally also called an electron extracting layer, a connecting layer, an intermediate layer, an intermediate electrode, an intermediate conductive layer, or an intermediate insulating layer, and may be made of a known material configuration. The tandem type is preferable because it is expected to improve the luminance and the luminescence life. Specific examples of the tandem type include laminated structures including a charge generation layer between an anode and a cathode, such as (4) hole transport layer/light-emitting layer/electron transport layer/charge generation layer/hole transport layer/light-emitting layer/electron transport layer, (5) hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/charge generation layer/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer, and (6) hole transport layer/light-emitting layer/electron transport layer/charge generation layer/hole transport layer/light-emitting layer/electron transport layer/charge generation layer/hole transport layer/light-emitting layer/electron transport layer.

Further, each of the above layers may be a single layer or a plurality of layers, and may be doped. In particular, the electron transport layer and charge generation layer are preferably metal-doped layers, which can improve the electron transport ability and the ability to inject electrons into other adjacent layers. Further, in addition to the above-mentioned layers, a protective layer (cap layer) may be further included, and the light emission efficiency can be further improved due to the optical interference effect. The thickness of each layer is generally selected from 1 nm to 200 nm in consideration of the resistance value of each layer material and the effect on the extraction efficiency of EL light emission.

<Alkali metal doped layer and/or rare earth metal doped layer (metal doped layer)>
In the present invention, in order to reduce the voltage of the light emitting element, an organic layer doped with a metal using the organic material constituting the organic EL layer as a host material, that is, a metal doped layer, is used. It may have multiple layers. The details of the organic material serving as the host material and the metal serving as the dopant material will be described later. This metal-doped layer can also be preferably used as a charge generation layer in a tandem light emitting device, and particularly as an n-type charge generation layer that supplies electrons. In this case, it is preferable to use it in combination with a p-type charge generation layer, which will be described later.

<Host material of metal doped layer>
The host material contained in the metal doped layer is preferably an electron transporting material, and may be a known compound such as a fused polycyclic aromatic compound derivative such as naphthalene or anthracene, a compound having a heteroaryl ring structure, or a metal complex such as an aluminum quinolinol complex. Among the compounds that can be used, it is preferable to use a compound having a heteroaryl ring structure containing electron-accepting nitrogen, from the viewpoint that the metal to be doped can easily coordinate and form a charge transfer complex.

The electron-accepting nitrogen referred to here refers to a nitrogen atom that forms a multiple bond with an adjacent atom. Since the nitrogen atom has high electronegativity, the multiple bond has electron-accepting properties. Therefore, a heteroaryl ring containing electron-accepting nitrogen has high electron affinity. Therefore, an electron transport material having electron-accepting nitrogen is likely to accept electrons from the doped metal and form a charge transfer complex. This improves the carrier density in the metal-doped layer, making it possible to drive the device at a lower voltage. In addition, the supply of electrons to the light-emitting layer increases, increasing the probability of recombination, thereby further improving the light-emitting efficiency.

Examples of heteroaryl ring skeletons containing electron-accepting nitrogen include triazine ring skeletons, pyridine ring skeletons, bipyridine ring skeletons, terpyridine ring skeletons, pyrazine ring skeletons, pyrimidine ring skeletons, quinoline ring skeletons, quinoxaline ring skeletons, and quinazoline ring skeletons. , naphthyridine ring skeleton, pyrimidopyrimidine ring skeleton, benzoquinoline ring skeleton, phenanthroline ring skeleton, imidazole ring skeleton, oxazole ring skeleton, oxadiazole ring skeleton, triazole ring skeleton, thiazole ring skeleton, thiadiazole ring skeleton, benzoxazole ring skeleton , benzothiazole ring skeleton, benzimidazole ring skeleton, phenanthroimidazole ring skeleton, etc., and compounds having these ring skeletons can be suitably used as host materials.

Among these, compounds having a triazine ring skeleton, a bipyridine ring skeleton, a terpyridine ring skeleton, a pyrimidine skeleton, or a phenanthroline ring skeleton are more preferable from the viewpoint of ease of forming a charge transfer complex with the metal to be doped. Or, a compound having a phenanthroline ring skeleton is more preferable.

That is, it is preferable that the alkali metal-doped layer and/or the rare earth metal-doped layer contain a compound having a phenanthroline skeleton.

It is also preferable that the alkali metal-doped layer and/or the rare earth metal-doped layer contain a compound having a terpyridine skeleton.

Details about compounds having a phenanthroline ring skeleton or a terpyridine ring skeleton will be described later.

In addition, compounds having a phosphine oxide skeleton can also be preferably used as a host material for the metal-doped layer, from the viewpoint of easily forming a charge transfer complex with the metal, improving the carrier density, and enabling low-voltage operation. The compounds having a phosphine oxide skeleton are preferably compounds having an alkyl group or an aryl group as a substituent, and more preferably compounds having an aryl group as a substituent. Preferred aryl groups as the substituent include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, and a pyrenyl group. These aryl groups may have a substituent.

Preferred host materials are not particularly limited, but specific examples include the following:

<Compound having a phenanthroline skeleton>
As described above, in the present invention, it is preferable to use a compound having a heteroaryl ring structure containing electron-accepting nitrogen as the host material of the metal doped layer. As a representative example thereof, it is preferable to include a compound having a phenanthroline skeleton represented by the following formula (7).

Here, R ₁ to R ₈ may be the same or different, and are selected from a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, a heteroaryl group, and a heterocyclic group.

Furthermore, in the present invention, the host material of the metal-doped layer preferably contains a compound having a polymer of a phenanthroline skeleton. As a representative example, it is more preferable to contain a phenanthroline polymer compound having multiple phenanthroline skeletons represented by the following formula (8), since this has excellent charge-transfer complex forming ability with the metal.

Here, R ₉ to R ₁₆ may be the same or different, and are selected from a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, a heteroaryl group, a heterocyclic group, and X _1. However, at least one of R ₉ to R ₁₆ is X _1. n represents a natural number of 2 to 6. X ₁ is a single bond or a linking unit that links n phenanthroline skeletons. X ₁ is preferably a single bond, an n-valent aromatic group, an n-valent aromatic heterocyclic group, an n-valent aliphatic group, or an n-valent group formed by combining these, and among these, an n-valent aromatic group is more preferable. Among the n-valent aromatic groups, an n-valent group derived from a benzene ring, a biphenyl ring, or a naphthalene ring is preferable, and an n-valent group derived from a benzene ring is more preferable. In addition, from the viewpoint of the thermal stability of the material, n is preferably 2 or 3, and more preferably n is 2.

Among the substituents R ₁ to R ₁₆ shown in formulas (7) and (8), alkyl groups include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec- It represents a saturated aliphatic hydrocarbon group such as a butyl group or a tert-butyl group, which may or may not have a substituent. There are no particular restrictions on the additional substituent when substituted, and examples thereof include an alkyl group, a halogen, an aryl group, a heteroaryl group, and this point is also common to the following description. Further, the number of carbon atoms in the alkyl group is not particularly limited, but from the viewpoint of availability and cost, it is preferably in the range of 1 to 20, more preferably 1 to 8. Furthermore, a cycloalkyl group refers to a saturated alicyclic hydrocarbon group such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group, which may or may not have a substituent. . The number of carbon atoms in the alkyl group moiety is not particularly limited, but is preferably in the range of 3 or more and 20 or less.

The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, or a butadienyl group, which may be unsubstituted or substituted. The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexene group, which may be unsubstituted or substituted. The alkynyl group refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an acetylenyl group, which may be unsubstituted or substituted. The alkoxy group refers to an aliphatic hydrocarbon group connected via an ether bond, such as a methoxy group, which may be unsubstituted or substituted. The alkylthio group refers to an alkoxy group in which the oxygen atom of the ether bond is replaced by a sulfur atom. The aryl ether group refers to an aromatic hydrocarbon group connected via an ether bond, such as a phenoxy group, which may be unsubstituted or substituted. The arylthioether group refers to an aryl ether group in which the oxygen atom of the ether bond is replaced by a sulfur atom. The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, a phenanthryl group, a terphenyl group, or a pyrenyl group, which may be unsubstituted or substituted. Furthermore, the heteroaryl group refers to a cyclic aromatic group having one or more atoms other than carbon in the ring, such as a pyridyl group, a furanyl group, a thiophenyl group, a quinolinyl group, an isoquinolinyl group, a pyrazinyl group, a pyrimidyl group, a pyridazinyl group, a triazinyl group, a naphthyridinyl group, a cinnolinyl group, a phthalazinyl group, a quinoxalinyl group, a quinazolinyl group, a benzofuranyl group, a benzothiophenyl group, an indolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzocarbazolyl group, a carbolinyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a dihydroindenocarbazolyl group, a benzoquinolinyl group, an acridinyl group, a dibenzoacridinyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, or a phenanthrolinyl group. Here, the naphthyridinyl group refers to any of 1,5-naphthyridinyl, 1,6-naphthyridinyl, 1,7-naphthyridinyl, 1,8-naphthyridinyl, 2,6-naphthyridinyl, and 2,7-naphthyridinyl groups. The heteroaryl group may or may not have a substituent. The number of ring-forming atoms is not particularly limited, but is preferably in the range of 3 to 40, more preferably 3 to 30. The heterocyclic group refers to an aliphatic ring having an atom other than carbon in the ring, such as a pyran ring, a piperidine ring, or a cyclic amide, which may or may not have a substituent. The number of carbon atoms in the heterocyclic group is not particularly limited, but is preferably in the range of 2 to 20.

In addition, if the substituent itself has a three-dimensional structure, or if it brings about a three-dimensional structure due to steric repulsion with the phenanthroline skeleton or adjacent substituents, the compound containing the phenanthroline skeleton will have low planarity and will be less likely to crystallize, and will be able to maintain a good amorphous thin film state. The substituent itself having a three-dimensional structure means, for example, a t-butyl group, an adamantyl group, or a norbornyl group that is not a two-dimensional planar structure and has a bulky three-dimensional structure, and may be unsubstituted or substituted. In addition, the substituent that brings about a three-dimensional structure due to steric repulsion with the phenanthroline skeleton or adjacent substituents means that even if the substituent itself has a planar structure, the plane of the substituent is in a different plane from the plane of the phenanthroline skeleton due to steric repulsion between the substituent and the phenanthroline skeleton, or between the substituent and adjacent substituents, such as an α-naphthyl group, a phenanthrene group, or a mesityl group. These can be considered using molecular models, computer chemistry, etc.

Furthermore, by linking multiple phenanthroline skeletons or multimerizing them, compounds containing phenanthroline skeletons have a higher molecular weight and a higher glass transition temperature, making crystallization less likely to occur and maintaining a good amorphous thin film state. It is more preferable because it can.

Among the compounds having a phenanthroline skeleton of formula (7) in the present invention, it is more preferable to introduce a substituent at the R ₁ , R ₃ , R ₆ or R ₈ position of the phenanthroline skeleton. Introducing substituents to the carbon atoms adjacent to the nitrogen atom, that is, the R ₁ and R ₈ positions, from the viewpoint of chemical stability of the compound, improving electron mobility, and enabling lower voltage operation. is even more preferable. These substituents are the same as those described above, but the substituents introduced at these positions are preferably an alkyl group, an aryl group, or a heteroaryl group, and more preferably an aryl group. Among the aryl groups, phenyl, naphthyl, and fluorenyl groups are preferred, and phenyl is more preferred.

In the phenanthroline multimer represented by the formula (8) of the present invention, it is preferable to introduce a substituent to R ₉ , R ₁₁ , R ₁₄ or R ₁₆ , from the viewpoint of chemical stability of the compound and electron transfer. It is more preferable to introduce substituents into the carbon atoms adjacent to the nitrogen atom, ie, at the R ₉ and R ₁₆ positions, from the viewpoint of improving the efficiency and enabling lower voltage driving. These substituents are the same as those described above, but the substituents introduced at these positions are preferably an alkyl group, an aryl group, or a heteroaryl group, and more preferably an aryl group. Among the aryl groups, phenyl, naphthyl, and fluorenyl groups are preferred, and phenyl is more preferred.

Specific examples of the compound having the above-mentioned phenanthroline skeleton include the following structures, but the structure is not limited thereto.

The organic EL element materials represented by formula (7) and formula (8) can be synthesized by a known synthesis method. For example, the synthesis method may be a coupling reaction between an aryl halide derivative and an arylboronic acid derivative using palladium, but is not limited thereto.

<Compounds Having a Terpyridine Skeleton>
As described above, in the present invention, the host material of the metal-doped layer is preferably a compound having a heteroaryl ring structure containing electron-accepting nitrogen. As a representative example, a compound having a terpyridine skeleton can also be suitably used. The terpyridine skeleton is a skeleton in which three pyridine rings are bonded in succession, and has a high coordination ability with the doped metal and is easy to form a charge transfer complex. If one terpyridine skeleton is contained in the molecule, it functions as a host material, but it is more preferable if two or more terpyridine skeletons are contained. In addition, as a result of focusing on the effects of a phenanthrolinyl group, a terpyridyl group, and their linking groups, all of them have a large electron transport property and are substituents with high coordination properties to metal atoms, so it is preferable to include a compound having a terpyridine skeleton represented by the following formula (9).

In the compound represented by formula (9), by selecting a phenylene group, naphthylene group or anthrylene group as L ¹ and a single bond, a phenylene group, a naphthylene group or anthrylene group as L ² , the phenanthrolinyl group, the terpyridyl group and their linking groups can be easily conjugated, and the charge transportability of the entire compound can be increased. Therefore, when used in an organic EL device, the driving voltage can be reduced and the luminous efficiency can be improved. In addition, since the coordination to metal atoms can be increased, when the compound represented by formula (9) is used in a metal-doped layer in an organic EL device, a stable layer can be formed.

In formula (9), L ¹ is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group, and L ² is a single bond, a substituted or unsubstituted phenylene group, a substituted or an unsubstituted naphthylene group or a substituted or unsubstituted anthrylene group. When L ¹ is substituted, the substituent is an alkyl group or an alkoxy group. These substituents are preferable because they can improve the stability of the compound without reducing the charge transport properties of the compound. From the viewpoint of increasing film quality stability and further improving luminous efficiency and durability life, it is preferable that L ¹ or L ² is a naphthylene group. Further, when L ² is a single bond, the interaction between the phenanthrolinyl group and the terpyridyl group can be further increased, and the luminous efficiency and durability can be further improved.

In formula (9), any one of X ¹ to X ³ is a nitrogen atom, and the others are methine groups. From the viewpoint of increasing coordination to metal atoms and forming a more stable layer, it is preferable that X ³ is a nitrogen atom. By forming a more stable layer, it is possible to drive at a lower voltage and further improve the durability life.

In formula (9), when n is 1, A is a phenyl group or a pyridyl group. When n is 1, the highly reactive 2- and 9-positions of the substitution positions of the phenanthroline are substituted, thereby improving the stability of the compound. Furthermore, by selecting a phenyl group or a pyridyl group as A, the nitrogen atom on the phenanthrolinyl group has high coordination, and when used in a metal doping layer, a more stable layer with higher metal coordination can be formed. This makes it possible to further reduce the driving voltage and improve the durability. From the viewpoint of further improving the stability and durability of the element, a phenyl group is preferable as A.

In formula (9), when n is 0, the 9-position of the phenanthroline is hydrogen. When n is 0, the phenanthroline is sterically empty, and therefore when used in a metal doping layer, it has higher metal coordination and can form a more stable layer.

The molecular weight of the compound represented by formula (9) is preferably 400 or more from the viewpoint of suppressing crystallization and improving the stability of film quality. On the other hand, from the viewpoint of improving processability during sublimation purification and vapor deposition, the molecular weight of the compound represented by formula (9) is preferably 640 or less.

Examples of the compound represented by the above formula (9) include the compounds shown below. Note that the following is just an example, and compounds other than those specified here are preferably used as long as they are represented by formula (9).

The organic EL element material represented by formula (9) can be synthesized by a known synthesis method. Examples of the synthesis method include, but are not limited to, a coupling reaction between a halogenated aryl derivative and an arylboronic acid derivative using palladium.

<Dopant material of metal doped layer>
Preferred examples of dopant materials include alkali metals, rare earth metals, and the like. Preferred examples of alkali metals, alkaline earth metals, and rare earth metals include alkali metals such as lithium, sodium, potassium, rubidium, and cesium, which have a low work function and have a large effect on improving electron transport ability, and magnesium, calcium, cerium, and barium. Examples include alkaline earth metals such as alkaline earth metals, and rare earth metals such as samarium, europium, and ytterbium. In particular, from the viewpoint of being able to further reduce the driving voltage, alkali metals and/or rare earth metals are preferred, and lithium or ytterbium is a typical example. A combination of two or more of these metals may be used. Furthermore, alloys of alkali metals or rare earth metals and other metals may be used. Specific examples of metals that can be used as materials for the alloy include zinc, cadmium, and bismuth, but are not limited thereto.

Furthermore, these metals are preferably in the form of an inorganic salt or a complex with an organic substance, rather than as a single metal, because they can be easily vapor-deposited in a vacuum and are easy to handle. Furthermore, it is more preferable to be in the state of a complex with an organic substance, since it can be easily handled in the atmosphere and the added concentration can be easily adjusted. Examples of inorganic salts include oxides such as LiO and _Li2O ; nitrides _; fluorides such as _LiF , _NaF , and KF; _Li2CO3 , _Na2CO3 , _{K2CO3 , Rb2CO3} , Examples include carbonates such as Cs ₂ CO ₃ .

<Hole transport layer>
The hole transport layer is formed, for example, by a method of laminating or mixing one or more hole transport materials, or by a method of using a mixture of a hole transport material and a polymer binder. Alternatively, the hole transport layer may be formed by adding an inorganic salt such as iron(III) chloride to the hole transport material. The hole transport material is not particularly limited as long as it is a compound that can form a thin film necessary for manufacturing a light emitting element, inject holes from an electrode serving as an anode, and transport holes. The hole transport layer may be a single layer or may be configured by laminating a plurality of layers.

Suitable examples of hole transport materials include triphenylamine derivatives such as 4,4'-bis(N-(3-methylphenyl)-N-phenylamino)biphenyl, 4,4'-bis(N-(1-naphthyl)-N-phenylamino)biphenyl, and 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, biscarbazole derivatives such as bis(N-allylcarbazole) and bis(N-alkylcarbazole), heterocyclic compounds such as pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, phthalocyanine derivatives, and porphyrin derivatives, and in the case of polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in the side chains, polythiophenes, polyanilines, polyfluorenes, polyvinylcarbazoles, and polysilanes.

<Light-emitting layer>
In the light-emitting layer, the injected electrons and holes recombine to emit light. A major feature of organic EL displays is that they are capable of emitting a variety of colors by selecting the materials that make up the light-emitting layer.

The light-emitting layer is a layer in which the light-emitting material is excited by the recombination energy due to collision of holes and electrons, and emits light. The light-emitting layer may be a single layer or may be composed of a laminate of multiple layers, each of which is formed of a light-emitting material (host material and/or dopant material). Each light-emitting layer may be composed of only one of the host material or the dopant material, or may be composed of a combination of one or more host materials and one or more dopant materials. That is, in each light-emitting layer, only the host material or the dopant material may emit light, or both the host material and the dopant material may emit light. From the viewpoint of efficiently using electrical energy and obtaining light emission with high color purity, it is preferable that the light-emitting layer is composed of a combination of a host material and a dopant material. The dopant material may be contained in the entire host material or in part.

The content of the dopant material in the light-emitting layer is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, based on 100 parts by weight of the host material, from the viewpoint of suppressing the concentration quenching phenomenon.

The light-emitting layer can be formed by co-evaporating a host material and a dopant material, or by premixing a host material and a dopant material and then evaporating the mixture.

Examples of the host material constituting the luminescent material include compounds having a fused aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene. Two or more types of these may be used. Suitable hosts used when the light-emitting layer emits triplet light (phosphorescence) include metal chelated oxinoid compounds, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, triphenylene derivatives, etc. used for. Among these, compounds having an anthracene skeleton or a pyrene skeleton are more preferable because they can easily provide highly efficient light emission.

Examples of dopant materials constituting the luminescent material include fused ring derivatives such as anthracene and pyrene, metal complex compounds such as tris(8-quinolinolato)aluminum, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, and tetraphenyl. Examples include butadiene derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, polyphenylene vinylene derivatives, and the like. Dopant materials used when the light-emitting layer emits triplet light (phosphorescence) include iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re). ) A metal complex compound containing at least one metal selected from the group consisting of: The ligands constituting the metal complex compound can be appropriately selected depending on the required emission color, organic EL display device performance, and relationship with the host compound. Preferably, it has an aromatic heterocycle. Specific examples include tris(2-phenylpyridyl)iridium complex, bis(2-phenylpyridyl)(acetylacetonato)iridium complex, and tetraethylporphyrin platinum complex. Two or more types of these may be used.

<Electron Transport Layer>
The electron transport layer is a layer that transports electrons injected from the cathode to the light-emitting layer. In order to achieve a low driving voltage, it is preferable that the organic EL layer of the present invention includes an electron transport layer. It is desired that the electron transport layer has a high electron injection efficiency and efficiently transports the injected electrons. Therefore, it is preferable that the electron transport layer is a material that has a large electron affinity and electron mobility, is excellent in stability, and is unlikely to generate impurities that become traps during production and use. In particular, when the film thickness is large, low-molecular-weight compounds are prone to crystallization and other deterioration in film quality, so compounds with a molecular weight of 400 or more are preferable. In addition, when considering the transport balance of holes and electrons, it is also preferable that the electron transport layer has a role of efficiently preventing holes that have not been recombined from flowing from the anode to the cathode, and the electron transport layer in the present invention also includes a hole blocking layer that can efficiently prevent the movement of holes. The electron transport layer may be a single layer or may be composed of a plurality of layers stacked together.

Examples of the electron transport material constituting the electron transport layer include fused polycyclic aromatic derivatives such as naphthalene and anthracene. Two or more types of these may be used. Among these, compounds having a heteroaryl ring structure containing electron-accepting nitrogen are preferred because they can further reduce the driving voltage and provide highly efficient light emission.

The electron-accepting nitrogen herein refers to a nitrogen atom forming multiple bonds with adjacent atoms. Since nitrogen atoms have high electronegativity, such multiple bonds have electron-accepting properties. Therefore, an aromatic heterocycle containing electron-accepting nitrogen has high electron affinity. An electron transport material having electron-accepting nitrogen can easily receive electrons from a cathode having a high electron affinity, so that the driving voltage can be further reduced. Furthermore, more electrons are supplied to the light-emitting layer, increasing the probability of recombination, and thus improving the light-emitting efficiency.

<p-type charge generation layer>
As described above, the metal-doped layer of the present invention functions favorably as an n-type charge generating layer that supplies electrons in a tandem-type light-emitting device, but in that case, it is common to use a p-type charge generating layer that supplies holes by laminating it. The p-type charge generating layer is usually formed by doping a small amount of a p-type dopant with high electron-accepting properties into a hole transport material. The hole transport material, which is the host material, is preferably an arylamine derivative material as described in the section on the hole transport layer. As the p-type dopant, a TCNQ derivative such as tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), a radialene derivative, iodine, FeCl ₃ , FeF ₃ , SbCl ₅ , etc. can be used, but a radialene derivative is preferred. In addition, a layer in which an arylamine derivative is laminated on a thin film of a hexaazatriphenylene compound called HATCN6 can also be used as a p-type charge generating layer.

<Second Electrode>
In the present invention, the second electrode 7 must be a light-reflective electrode in the case of a bottom emission type, and a light-transmitting electrode in the case of a top emission type.

If it is a bottom emission type, it is preferable to use a material that exhibits a high reflectance of visible light at a certain thickness or more and a low electrical resistance, and Ag or an Ag alloy film containing Ag as a main component is useful because of its high reflectance. be. As the Ag alloy film, a MgAg alloy containing Ag as a main component or the like can be used. Furthermore, Al or an Al alloy film containing Al as a main component is also suitable as the second electrode for bottom emission. An AlCr alloy film containing Cr and an AlNi alloy film containing Ni are preferable because they have a reflectance as high as that of pure Al and can realize low electrical resistance.

If it is a top emission type, for example, transparent conductive metal oxides such as tin oxide, indium oxide, and indium tin oxide (ITO) can be used, but in order to avoid damage to the organic EL layer, vapor deposition A thin film of an MgAg alloy that can be produced by is preferred.

Like the first electrode, the resistance of the second electrode is not limited as long as it can supply sufficient current for light emission of the light emitting element, but from the viewpoint of power consumption of the light emitting element, a low resistance is desirable. The thickness of the electrode can be arbitrarily selected according to characteristics such as transmittance and resistance value, but for bottom emission type, it is 100 nm to 300 nm, and for top emission type, it is 10 nm to 30 nm. can.

<Wiring, TFT>
In the present invention, as described above, wiring and driving circuits such as TFTs 8 may be provided as components included in the base material 1 .

When the organic EL display device is an active-drive top-emission type, the patterned island-shaped first electrode 2 is often connected to a TFT that is formed in advance as part of the substrate 1.

Semiconductor layers for TFTs include a-Si (amorphous silicon), p-Si (polycrystalline silicon), microcrystalline silicon, oxides such as In-Ga-Zn-O, and p-Si and oxides. There are LTPO (Low Temperature Polycrystalline Oxide) which uses a combination of materials, but generally two types are used: a-SiTFT and p-SiTFT. Although a-Si TFTs have low mobility, which is an indicator of how easily electrons move, they require a relatively short manufacturing process and can be manufactured on large substrates, so they can be used in a wide range of applications from small to large displays. On the other hand, p-Si TFTs have high mobility and can be used to form driver circuits on the substrate. The manufacturing process is longer than a-Si, and large substrates are difficult to manufacture, so it is preferable to use it mainly for small and medium-sized displays. In particular, p-Si in a p-Si TFT can generally be formed by using a-Si as a starting film and irradiating it with a laser to instantaneously melt and crystallize it. In addition, there is a doping process in which phosphorus or boron is injected into Si, which is not used in the a-Si TFT manufacturing process, and the threshold value of TFT characteristics may be controlled by doping impurities into the Si film.

From the structural standpoint, TFTs can be broadly classified into bottom-gate and top-gate types. It is preferable to use the bottom-gate type for a-Si TFTs and the top-gate type for p-Si TFTs. For example, in the top-gate type, the drain electrode and source electrode are connected to the semiconductor layer, and the gate electrode is provided above the semiconductor layer. TFTs are formed on a substrate by repeating the elemental processes of thin-film formation, patterning, etching, and cleaning several times. TFTs can be formed using known methods. In the bottom-gate type, the gate electrode is placed at the bottom layer, the semiconductor layer/insulating film is placed above it, and the source electrode and drain electrode are formed on the top layer. A structure called an "inverted staggered structure" in which a straight line connecting the gate electrode, source electrode, and drain electrode forms an inverted triangle may also be used.

<Planarization Layer>
In particular, in the case of an active driving type, for example, when wiring or TFT 8 is provided inside the substrate 1 as shown in FIG. 2, it is preferable to use a planarization layer 9. By providing a planarization layer, the unevenness of the wiring or TFT can be covered and planarized. In this case, since the first electrode 2 is provided on the planarization layer, it is preferable that the first electrode and the wiring or TFT are connected through a contact hole formed in the planarization layer. The planarization layer is not limited to either a known organic material or an inorganic material, but preferably contains a cured film of a photosensitive resin composition from the viewpoint of processability. The planarization layer can be applied by a wet coating method such as a spin coating method, a slit coating method, a dip coating method, a spray coating method, or a printing method that can uniformly form a thin film on a large-sized substrate.

The photosensitive resin composition contained in the planarization layer preferably contains (A) an alkali-soluble resin, (B) a photosensitizer, and (C) an organic solvent, and may further contain (D) a coloring material. By containing (A) an alkali-soluble resin and (B) a photosensitizer in combination as the photosensitive resin composition, pattern processing using photosensitivity becomes possible. In addition, by containing (C) an organic solvent, it is possible to make it in a varnish state, which may improve the coatability. Furthermore, by containing (D) a coloring material in the photosensitive resin composition, the planarization layer can be blackened. The photosensitive resin composition may further contain other components.

Examples of materials for the alkali-soluble resin (A) include acrylic resins, epoxy resins, polyamide resins, siloxane resins, and precursors of these resins, especially if the film thickness is sufficient to cover unevenness. Not limited. If coloring is required from the viewpoint of light-shielding properties or antireflection, it is preferable to contain a coloring material as appropriate.

<Spacer>
Furthermore, in order to support the structure covering the second electrode 7 in a subsequent process and ensure the strength of the display device, it is preferable to form a spacer on the pixel dividing section 4. However, as described above, in the present invention, the concavo-convex structure existing between adjacent display pixels is defined as a dam part, and therefore, what is provided on the pixel division part is called a spacer to distinguish it from the dam part.

In the organic EL display device of the present invention, the spacer is provided on the pixel dividing section. The first purpose is that by providing the spacer, the contact area between the substrate and the vapor deposition mask when forming the organic EL layer can be reduced, thereby suppressing the generation of particles during the process. As a result, a decrease in panel yield and deterioration of light emitting elements can be suppressed. As a second purpose, as described above, it is necessary to fabricate spacers on the pixel dividing layer in order to support the structure covering the second electrode in the post-process and ensure the strength of the display device. Like the pixel division layer, the spacer requires patterning, and the residue from the removed portion may directly lead to defects such as short circuits and black spots. Furthermore, since the shape of the edge of the spacer may cause disconnection of the second electrode, workability such as a gently tapered shape is also required.

The spacer can be any material having the necessary mechanical and electrical properties, and is not limited to either known organic or inorganic materials, but is preferably a cured film of a photosensitive resin composition from the standpoint of processability. In addition, by forming the spacer using the same material as the pixel dividing layer in a single process, it is possible to shorten the process time, improve the panel yield, and reduce costs.

In addition, since the shape of the edge of the spacer can cause the second electrode to break, a gentle forward tapered shape is preferable. Here, a forward tapered shape refers to a state in which the angle formed by the tangent at the interface between the pixel division section and the spacer and the tangent at a position where the film thickness is 50% of the maximum thickness of the spacer on the surface of the tapered part of the spacer is less than 90°.

The thickness of the spacer is usually 0.3 μm to 10 μm, but is not particularly limited as long as it is sufficient to support the structure covering the second electrode and to contact the deposition mask.

<Sealing layer>
After forming the second electrode 7, it is preferable to seal with a sealing layer 10 as shown in FIG. 15. This is because organic EL light-emitting elements are considered to be vulnerable to oxygen and moisture, and in order to obtain a highly reliable display device, it is preferable to seal in an atmosphere with as little oxygen and moisture as possible. It is also preferable to select a material with high gas barrier properties for the sealing layer, and similarly to the substrate 1, it is appropriately selected from glass, resin film, gas barrier film, etc. For example, as an example of a gas barrier film, materials such as SiO ₂ (silicon oxide), SiN (silicon nitride), and SiON (silicon oxynitride) can be mentioned. In addition, a sealing layer made of a resin material such as an acrylic resin or a silicone resin may be provided on a layer formed using materials such as _{SiO 2} (silicon oxide), SiN (silicon nitride), and SiON (silicon oxynitride). In the case of a top-emission type display device, it is preferable to form it from a light-transmitting material.

In addition, when adhesion is required, adhesives with high gas barrier properties are required, such as two-component epoxy adhesives (XNR, manufactured by Nagase ChemteX Co., Ltd.) and sealing materials for organic devices (Moisture Cut, It may be selected from commonly known materials such as those manufactured by MORESCO Co., Ltd.), or a method may be used in which frit glass is melted with a laser in the peripheral area of the display device.

As a further consideration to moisture, it is also effective to introduce a desiccant during the sealing process. Known desiccants include barium oxide and calcium oxide, but there is no particular limitation as long as they have high moisture adsorption performance.

<Polarizing Layer>
The organic EL display device of the present invention preferably further includes a polarizing layer 11 as shown in FIG. 15. Specifically, a linear polarizing layer and a λ/4 retardation layer are laminated to suppress reflection of light incident on the display device from the outside. The linear polarizing layer is not particularly limited, but for example, a film obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it is often used. The material constituting the λ/4 retardation layer is also not particularly limited, but a heat-resistant polyimide resin is preferable.

<Ultraviolet absorbing layer>
The organic EL display device of the present invention preferably further includes an ultraviolet absorbing layer 12 as shown in FIG. 15, for example. By including the ultraviolet absorbing layer, deterioration of the substrate and the organic EL layer 5 due to ultraviolet rays can be suppressed, and the reliability of the display device can be improved. As the ultraviolet absorbing layer, a layer that absorbs light having a wavelength of 320 nm or less is preferable, a layer that absorbs light having a wavelength of 360 nm or less is more preferable, and a layer that absorbs light having a wavelength of 420 nm or less is even more preferable. However, since light having a wavelength of 420 nm or more overlaps with the emission wavelength of blue light used for display, it is preferable that the ultraviolet absorbing layer has a high transmittance in the wavelength range of 420 nm or more. This is particularly effective when the organic EL display device of the present invention is used outdoors.

<Method for manufacturing organic EL display device>
The organic EL display device of the present invention is an organic EL display device having a substrate having a first electrode and a pixel dividing layer on the base material, further comprising an organic EL layer and a second electrode, and wherein the pixel dividing layer has a pixel opening. The organic EL display device includes a pixel dividing section and a dam section, and the organic EL layer includes an alkali metal doped layer or a rare earth metal doped layer. An example of the method for manufacturing an organic EL display device of the present invention will be described using the case of manufacturing a top emission type organic EL display device shown in FIG. 15 as an example.

First, wiring and TFT 8 are provided on base 1a, which is a resin film. In addition to the TFT formation processes such as ``gate electrode formation process,'' ``gate insulating film formation process,'' ``Si film formation process,'' and ``source and drain electrode formation process,'' the process includes ensuring electrical connection. All wiring can be formed using known methods.

Next, the planarization layer 9 is applied by slit coating to form a film, and then heated and cured. At this time, contact holes are provided for the purpose of connection with the first electrode 2. If the material used for the planarization layer 9 is photosensitive, this can be achieved by photolithography, and if it is not photosensitive, this can be achieved by general etching using a resist material as a mask. In this way, the substrate 1 is completed.

Subsequently, films of AgPdCu and ITO are sequentially formed on the base material as the first electrode 2, and patterned to form the first electrode 2.

The organic EL display device of the present invention has a pixel dividing portion and a dam portion of the pixel dividing layer in the gap of the first electrode 2, and the pixel opening, which is the opening of the pixel dividing layer, becomes a display pixel.

The pixel division part and the dam part, which are the characteristics of the organic EL display device of the present invention, can be formed by a general method. For example, regardless of whether the dam part has a convex structure or a concave structure, an insulating material is processed over the area of the pixel dividing part and the dam part, and then a convex or concave structure is applied to the necessary locations between pixels. You can choose the method of additional machining. The material and processing method for additionally machining the dam part into a convex shape may be the same as or different from that of the pixel dividing part. Further, in the case of a concave structure, a processing method such as dry etching or wet etching can be selected, and the taper angle may be adjusted by selecting isotropic or anisotropic conditions.

To control the taper angle of the dam section, which is particularly important, it is preferable to appropriately adjust the exposure and development of the photosensitive material, as well as the curing conditions, for ease of processing. In particular, it is preferable to adjust the taper angle of the dam section by adjusting the gap amount of the proximity exposure and the focus of the stepper exposure in the exposure conditions, the selection of the developer in the development conditions, and the temperature rise rate in the curing conditions.

For example, in the curing conditions, the crosslinking reaction can be progressed by heat treatment (post-baking) using a heating device such as a hot plate or oven at a predetermined temperature, for example, 180 to 250° C., for a predetermined time, for example, 5 to 90 minutes on a hot plate, or 30 to 120 minutes in an oven. Before this post-baking, baking at a relatively low temperature (middle baking) can also be performed. Furthermore, middle baking and post-baking can be performed in multiple stages of three or more. By such ingenuity in middle baking and post-baking, the taper angle of the dam portion can be adjusted. For these heating treatments, known heating methods such as a hot plate, oven, and infrared heater can be used. In addition, prior to the post-baking, the developed substrate can be re-exposed (bleached) to active light on the entire surface.

Furthermore, surface roughness can be adjusted by combining several methods, such as mechanical polishing using an abrasive, shot blasting or wet blasting that sprays an abrasive, plasma discharge treatment, and RIE. . In this case, since the light emitting element is sensitive to oxygen and moisture, a dry process is preferable, and can be selected from glow discharge treatment, plasma discharge treatment, RIE, UV/ozone treatment, etc. In particular, a dry process using a highly reactive atmosphere such as oxygen has a large effect on surface roughness, and RIE is preferable.

Subsequently, the organic EL display device of the present invention has a step of forming an organic EL layer 6. Each layer such as a hole transport layer, a light emitting layer, and an electron transport layer constituting the organic EL layer 6 can be formed by a known method, for example, by a vacuum evaporation method or an inkjet method. In the present invention, since it is necessary to control the thickness of the metal doped layer on the tapered surface of the dam part, the vacuum evaporation method is particularly preferred. With the vacuum evaporation method, the film thickness on the tapered surface of the dam part can be adjusted by adjusting the mutual position of the substrate and the evaporation source, which is called an offset amount.

Mask deposition, which is one of the vacuum deposition methods, is a method of depositing and patterning an organic compound using a deposition mask. For example, a deposition mask with openings of a desired pattern is placed on the deposition source side of a substrate and deposition is performed. In order to obtain a highly accurate deposition pattern, it is important to closely attach a highly flat deposition mask to the substrate. Generally, a technique of applying tension to the deposition mask or a technique of closely attaching the deposition mask to the substrate using a magnet placed on the back of the substrate can be used. Examples of methods for manufacturing a deposition mask include etching, mechanical polishing, sandblasting, sintering, laser processing, the use of photosensitive resins, and electroforming. When a fine pattern is required, it is preferable to use etching or electroforming, which have excellent processing accuracy.

The mask vapor deposition method and the inkjet method are more difficult as the pattern becomes finer, so for example, it is required to employ the minimum necessary amount of a light-emitting layer that determines the color of the emitted light. In this case, for example, by making the hole transport layer, electron transport layer, metal doped layer, etc. other than the light emitting layer common to each color, it is possible to form a film on the entire surface, improving the yield of the panel and reducing costs. Can be done.

The organic EL display device of the present invention further includes a second electrode 7. Although a known method can be used for the formation method, a vacuum evaporation method is preferable because deterioration and damage to the underlying organic EL layer 6 can be easily avoided.

In the method for manufacturing the organic EL display device of FIG. 15, after the step of forming the second electrode 7, the sealing layer 10, the polarizing layer 11, and the ultraviolet absorbing layer 12 are laminated in this order. Each layer can be formed by a known method, and the organic EL display device of FIG. 15 is completed in this manner.

The present invention will be explained below with reference to examples, but the present invention is not limited to these examples.

In each of the following evaluations, where the number of tests n was not listed, the evaluation was performed with n=1.

<Design of pixel division section and dam section>
The design of the first electrode, pixel division section, and dam section of the substrate used in the electrical reliability test and bending reliability test described later will be explained with reference to the schematic diagram of Fig. 16. The first electrode 2 was fabricated in a stripe shape of 100 lines, each having a line width of 60 µm, a pitch of 100 µm, and a length of 10 mm, in the center of the substrate 1 (100 mm x 100 mm). That is, the exposed portion of the substrate 1 at this point has a width of 40 µm.

Aligned with the center of this exposed portion, the insulating layer was prepared in a stripe shape with a line width of 60 μm, a pitch of 100 μm, and a length of 10 mm, with 101 stripes. Furthermore, in order to make a dam section with a width of 20 μm aligned with the center of the line width of 60 μm, and to make a pixel opening 40 μm, a pixel division section 20 μm, a dam section 20 μm, and a pixel division section 20 μm into a repeating unit, the following specific processing was performed. In the case of a dam section with a convex structure, an insulating layer with a width of 20 μm was prepared in a stripe shape similar to the pixel division section. In addition, in the case of a dam section with a concave structure, the 20 μm width was appropriately removed by etching, but when the photosensitive resin composition of the pixel division section and the dam section was different, the etching was performed until the first electrode was exposed, and then an insulating layer was additionally processed on the dam section. In this way, a substrate with a stripe-shaped first electrode with a pixel opening 40 μm, a pixel division section 20 μm, a dam section 20 μm, and a pixel division section 20 μm into a repeating unit was obtained.

<Surface roughness of pixel division section and dam section>
The surface roughness of the pixel division portion and the dam portion in each of the examples and comparative examples was determined by observing the pixel division portion and the dam portion of the same patterned substrate (100 mm x 100 mm) as used in the electrical reliability test and bending reliability test described below with an atomic force microscope (AFM, Dimension Icon, manufactured by Bruker Corp.). The observation conditions were RTESP-300 probe, tapping mode, scan size 5 μm square, scan rate 0.1 Hz, and number of sample lines 1,024.

Observation of Silica Particles Contained in the Pixel Dividing Layer
The silica particles contained in the pixel division layer in each Example and Comparative Example were obtained by observing the pixel division layer of the same patterned substrate (100 mm x 100 mm) as used in the electrical reliability test and bending reliability test described later by transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX) at a magnification of 50,000 times, using an image analysis type particle size distribution measuring instrument (Mac-View, manufactured by MOUNTECH). That is, 30 silica particles on the TEM image were randomly selected in the cross section of the pixel division layer of the patterned substrate (test n number 30), and the major axis, minor axis and aspect ratio on the TEM image for each were measured, and the major axis (nm) was 5 nm to 30 nm and the aspect ratio was in the range of 1.0 to 1.5. The silica particles were defined as component (a). Note that when the minor axis and major axis on the TEM image of one silica particle were equal, that is, when it was a perfect circle, the diameter was considered to be the major axis. As representative values showing the characteristics of the silica particles corresponding to component (a), the average primary particle diameter, i.e., the average long diameter, was calculated and rounded to the nearest tenth, and the average aspect ratio, i.e., the average aspect ratio of each of the silica particles corresponding to component (a) was calculated and rounded to the nearest tenth, was used.

The presence or absence of component (a) in each example and comparative example was rated as A for the presence of component (a) and B for the absence of component (a).

<Dam section structure, observation of the taper of the dam section, film thickness of the pixel division section and step of the dam section, film thickness measurement of the metal-doped layer on the pixel division section and the tapered surface of the dam section>
The structure of the dam part, taper observation of the dam part, the film thickness of the pixel division part and the step of the dam part, and the film thickness of the metal-doped layer on the pixel division part and the tapered surface of the dam part in each example and comparative example were evaluated by observing the cross section of the organic EL display device used in the electrical reliability test and bending reliability test described later. Specifically, a cross section was prepared by the FIB method using SMI3200SE manufactured by SIINT and FB-2000A μ-Sampling System manufactured by Hitachi High-Tech Corporation, and observed with a transmission electron microscope (H-9000UHR No. 2 manufactured by Hitachi High-Tech Corporation). The acceleration voltage in the observation with the transmission electron microscope was 300 kV. Regarding the structure of the dam part among the evaluation items, the case where it was a convex structure was judged as A, and the case where it was a concave structure was judged as B.

<Drive voltage test>
The driving voltage test in each Example and Comparative Example was conducted by selecting an arbitrary first electrode and a second electrode and driving them with DC at 10 mA/cm ² in the organic EL display device manufactured in each Example and Comparative Example described later. , the initial driving voltage was measured. A source meter (2400, manufactured by Keithley Instruments, Inc.) was used to measure the voltage, and the test was conducted 10 times (test n: 10), and the result of rounding off the average value to the second decimal place was used. The drive voltage in the evaluation results is preferably low, with (A) less than 2.5V, (B) more than 2.5V and less than 3.0V, (C) more than 3.0V less than 3.5V, and (C) more than 3.5V. Less than 4.0V was evaluated as (D), and 4.0V or more was evaluated as (E).

<Electrical reliability test>
The electrical reliability test of the organic EL display device in each example and comparative example was conducted by applying a voltage of 5 V between two adjacent striped first electrodes in the organic EL display device manufactured in each example and comparative example described below. The current value when applied was measured. A source meter (2400, manufactured by Keithley Instruments, Inc.) was used for the measurement, and the test was conducted at 20 locations (n number of tests: 20). Furthermore, the average value of 10 measurements was used, excluding 5 large and 5 small measurements.

The smaller the resulting current value, the smaller the leakage current and the better the electrical reliability was judged to be. The evaluation results were rated as A for less than 5.0×10 ^-6 mA, B for 5.0×10 ^-6 mA or more and less than 1.0×10 ^-5 mA, C for 1.0×10 ^-5 mA or more and less than 5.0×10 ^{-5 mA, D for 5.0×10 -5 mA} or more and less than 1.0×10 ^-4 mA, and E for 1.0×10 ^-4 mA or more.

<Bending reliability test>
The bending reliability test of the organic EL display device in each example and comparative example was performed using the organic EL display device manufactured in each example and comparative example described later. As shown in FIG. 17, a metal cylinder with a diameter of 5 mm was fixed to the center of the surface opposite to the surface on which the light-emitting element was formed of a substrate (100 mm×100 mm) on which the light-emitting element was formed, and the substrate was repeatedly folded along the cylinder within a range from an embrace angle of 0° (substrate in a flat state) to an embrace angle of 180° (state folded back by the cylinder), and the folded portion was observed with an optical microscope. Those in which peeling occurred after 1 to 49 bending operations were judged to have low bending reliability as characteristic (E), those in which peeling occurred after 50 to 99 bending operations were judged to have characteristic (D), those in which peeling occurred after 100 to 499 bending operations were judged to have characteristic (C), those in which peeling occurred after 500 to 999 bending operations were judged to have characteristic (B), and those in which peeling occurred 1,000 times or more were judged to have high bending reliability as characteristic (A). The test was performed 10 times (test number n: 10), and the result with the smallest number of times until peeling occurred was adopted.

<Preparation of Photosensitive Resin Composition>
The photosensitive resin compositions R-1 to R-6 used in the respective Examples and Comparative Examples were prepared as follows. Note that, among the compounds used, the names of those using abbreviations are shown below.
BAHF: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane BYK-333: Silicone surfactant BYK333 (manufactured by BYK-Chemie)
DFA: N,N-dimethylformamide dimethyl acetal DPCA-60: dipentaerythritol hexaacrylate modified with 6 moles of caprolactone (a hexafunctional acrylate having six pentyleneoxy chains, manufactured by Nippon Kayaku Co., Ltd.)
GA-5060P: fluorene-based acrylate monomer (manufactured by Osaka Gas Chemicals Co., Ltd.)
GBL: γ-butyrolactone MAP: 3-aminophenol; meta-aminophenol MBA: 3-methoxy-n-butyl acetate MEK-ST-40: Silica particle dispersion (manufactured by Nissan Chemical Industries, Ltd.). The solvent type is methyl ethyl ketone MEK-ST-L: Silica particle dispersion (manufactured by Nissan Chemical Industries, Ltd.). The solvent type is methyl ethyl ketone NMP: N-methyl-2-pyrrolidone ODPA: 4,4'-oxydiphthalic anhydride OSCAL-1421: Silica particle dispersion (manufactured by JGC Catalysts and Chemicals Industries, Ltd.). The solvent type is isopropyl alcohol OXE03: "Irgacure" (registered trademark) (manufactured by BASF Japan)
PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate S0100CF: "Irgaphor" (registered trademark) Black S0100CF
SiDA: 1,3-bis(3-aminopropyl)tetramethyldisiloxane TR4020G: cresol novolac resin (manufactured by Asahi Organic Chemicals Co., Ltd.)
TrisP-PA: 1,1-bis(4-hydroxyphenyl)-1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethane (manufactured by Honshu Chemical Industry Co., Ltd.)
ZAH-106: Binder for electronic materials "FOLET" (registered trademark) (manufactured by Soken Chemical & Engineering Co., Ltd.)
ZCR-1569H: Acid-modified epoxy acrylate resin (manufactured by Nippon Kayaku Co., Ltd.)
Pigment dispersant 1: A polymer-type dispersant having a linear polyalkyleneamine structure and a polyether-based polymer chain was synthesized as follows.

103.00 g of diethylenetriamine (1 mol) was charged into pressure vessel 1 and heated to 100°C while stirring under a nitrogen atmosphere. Next, 4405.00 g of ethylene oxide (100 mol) was charged into pressure vessel 2 and heated to 100°C. Under a pressure of 0.1 to 0.3 MPa, vaporized ethylene oxide was continuously fed into pressure vessel 1 through a gas inlet tube while pressurizing with nitrogen gas, and stirring was performed for 10 minutes, obtaining an addition reaction product A of diethylenetriamine and ethylene oxide. After natural cooling to 25°C, the system was opened, and 0.5 g of potassium hydroxide was added as an alkaline catalyst to promote addition polymerization. After stirring, the system was heated again to 100°C, and vaporized ethylene oxide was continuously fed into pressure vessel 1 while stirring for 2 hours, obtaining an addition reaction product B.

Separately, 5,810.00 g of propylene oxide (100 mol) was charged into pressure vessel 3 and heated to 100°C. Under a pressure of 0.1 to 0.3 MPa, vaporized propylene oxide was continuously pumped into pressure vessel 1 through a gas inlet tube while being pressurized with nitrogen gas and stirred for 3 hours, yielding addition reaction product C. 50.00 g of solid acid adsorbent (synthetic aluminum silicate) was added at 50°C and stirred for 3 hours to adsorb the alkali catalyst, which was then removed by filtration, yielding pigment dispersant 1, which is pale yellow in color and liquid at room temperature/atmospheric pressure.

The end points for the amounts of ethylene oxide and propylene oxide fed into the pressure vessel 1 were set so that the average number of moles of ethylene oxide grafted onto diethylenetriamine was equal to the average number of moles of propylene oxide added, and the sum of the average number of moles added was set so that the amine value of the final pigment dispersant 1 was 20 (mg KOH/g).

The chemical structure of Pigment Dispersant 1 was analyzed using a nuclear magnetic resonance apparatus ( ¹ H-NMR), and the ratio of the average number of added moles of ethylene oxide to the average number of added moles of propylene oxide was determined by the peak area ratio (ethylene Protons derived from oxide: chemical shift: 3.65 ppm, protons derived from propylene oxide: chemical shift: 1.10 ppm), the molar ratio finally added to diethylenetriamine was quantified and confirmed. Furthermore, it was also confirmed that the alkylene oxide structures of Pigment Dispersant 1 were only ethylene oxide structures and propylene oxide structures, and that there was no other contamination. Separately, analysis using infrared absorption spectra was conducted, and the disappearance of the absorption peak at a wavelength of 1,550 cm ^-1 confirmed the disappearance of secondary amino groups derived from diethylenetriamine, while at 1,600 cm ^-1 Since the disappearance of the absorption peak confirmed the disappearance of the primary amino group derived from diethylenetriamine, it was thought that all the hydrogen atoms of diethylenetriamine used as a raw material were substituted with polyalkylene oxide and tertiaryized.

Furthermore, as a result of analysis using pyrolysis GC-MS (column temperature was 40°C as a starting point and the temperature was increased to 320°C at a rate of 20°C per minute), it was found that the structure expressed by formula (10) was A tertiary amine compound (N,N-diethylmethylamine), which is thought to be a thermal decomposition product after polyether polymer chains are cleaved by heating, was detected, and three carbon atoms were bonded to the nitrogen atom derived from diethylenetriamine. It was confirmed that it was in the following form. Finally, the amine value was determined by potentiometric titration according to "JIS K2501 (2003)" and was found to be 20 (mgKOH/g). As a result of analysis, it was confirmed that the pigment dispersant 1 synthesized by the above procedure was the desired compound.

Pigment dispersant 1 corresponds to the pigment dispersant represented by the following formula (11), where n is 2, and R ²² to R ²⁵ , which are the terminal groups of the polyether polymer chain, are all hydrogen atoms. , (x ¹ +x ² +x ³ +x ⁴ )/(x ¹ +x ² +x ³ +x ⁴ +y ¹ +y ² +y ³ +y ⁴ )=0.50, R ²² to R ²⁵ are hydrogen atoms, and the amine value is 20 (mgKOH/g) and a solid content of 100% by weight, it is a pigment dispersant having a linear polyalkylene amine structure and a polyether polymer chain.

Pigment dispersant 2: Pigment dispersant 2 having an amine value of 20 (mgKOH/g) was synthesized as follows.

103.00 g of diethylenetriamine (1 mol) was charged into a pressure vessel 1, and the temperature was raised to 100° C. with stirring under a nitrogen atmosphere. Next, 4405.00 g of ethylene oxide (100 mol) was charged into the pressure container 2, heated to 100°C, and the vaporized ethylene oxide was injected with nitrogen gas through a gas blowing pipe under a pressure of 0.1 to 0.3 MPa. The mixture was stirred for 10 minutes while being continuously fed into the pressure container 1 under pressure, thereby obtaining an addition reaction product A of diethylenetriamine and ethylene oxide. After being naturally cooled to 25°C, the system was made into an open system, and 0.5g of potassium hydroxide was added as an alkali catalyst to promote addition polymerization. After stirring, the temperature was raised to 100°C again, and vaporized in a pressure vessel Stirring was carried out for 2 hours while continuously feeding ethylene oxide, and addition reaction product B was obtained. Separately, 5,810.00 g of propylene oxide (100 mol) was charged into pressure vessel 3, and the temperature was raised to 100°C. Then, under a pressure of 0.1 to 0.3 MPa, the vaporized propylene oxide was continuously fed into the pressure vessel 1 while being pressurized with nitrogen gas through the gas blowing pipe, and stirred for 3 hours to form the addition reaction product C. I got it. Add 50.00g of solid acid adsorbent (synthetic aluminum silicate) at 50℃ and stir for 3 hours to adsorb the alkali catalyst, then remove it by filtration to give a pale yellow color at room temperature/atmospheric pressure. A liquid pigment dispersant 2 was obtained.

The end points for the amounts of ethylene oxide and propylene oxide fed into the pressure vessel 1 were set so that the average number of moles of ethylene oxide grafted onto diethylenetriamine was equal to the average number of moles of propylene oxide added, and the sum of the average number of moles added was set so that the amine value of the final pigment dispersant was 20 (mg KOH/g).

<Synthesis of polyimide (PI-1)>
In a three-necked flask under a stream of dry nitrogen, 31.13 g (0.085 mol; 77.3 mol% based on structural units derived from total amines and derivatives) of BAHF and 6.21 g (0.0050 mol; total amine) of SiDA were added. 2.18 g (0.020 mol; 9.5 mol% based on the structural units derived from all amines and their derivatives) and 2.18 g (0.020 mol) of MAP as an end capping agent. ), 150.00 g of NMP was weighed and dissolved. To this, a solution of 31.02 g (0.10 mol; 100 mol% based on the structural units derived from all carboxylic acids and their derivatives) of ODPA dissolved in 50.00 g of NMP was added, stirred at 20 ° C. for 1 hour, and then The mixture was stirred at 50°C for 4 hours. Thereafter, 15 g of xylene was added, and the mixture was stirred at 150° C. for 5 hours while water was azeotroped with the xylene. After the reaction was completed, the reaction solution was poured into 3 L of water, and the precipitated solid precipitate was filtered. The obtained solid was washed three times with water and then dried in a vacuum dryer at 80° C. for 24 hours to obtain polyimide (PI-1).

<Synthesis of polyimide precursor (PIP-1)>
Under a dry nitrogen stream, 31.02 g (0.10 mol; 100 mol% relative to the total structural units derived from carboxylic acids and their derivatives) of ODPA and 150 g of NMP were weighed and dissolved in a three-neck flask. A solution of 25.64 g (0.070 mol; 56.0 mol% relative to the total structural units derived from amines and their derivatives) of BAHF and 6.21 g (0.0050 mol; 4.0 mol% relative to the total structural units derived from amines and their derivatives) of SiDA was added to 50 g of NMP, and the mixture was stirred at 20 ° C. for 1 hour, and then stirred at 50 ° C. for 2 hours. Next, a solution of 5.46 g (0.050 mol; 40.0 mol% relative to the total structural units derived from amines and their derivatives) of MAP was added to 15 g of NMP as a terminal blocking agent, and the mixture was stirred at 50 ° C. for 2 hours. Thereafter, a solution in which 23.83 g (0.20 mol) of DFA was dissolved in 15 g of NMP was added. After the addition, the mixture was stirred at 50° C. for 3 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and then the reaction solution was added to 3 L of water, and the precipitated solid was obtained by filtration. The obtained solid was washed three times with water and then dried in a vacuum dryer at 80° C. for 24 hours to obtain a polyimide precursor (PIP-1).

<Synthesis of Acrylic Copolymer (AC-1)>
Charge 100g of isopropyl alcohol into a 1,000cc four-neck flask, keep it in an oil bath at 80 ° C., seal with nitrogen, and stir while mixing 30g of methyl methacrylate, 40g of styrene, and 30g of methacrylic acid with 2g of N.N-azobisisobutyronitrile, and drop this over 30 minutes with a dropping funnel. After continuing the reaction for 4 hours, add 1g of hydroquinone monomethyl ether and then return to room temperature to complete polymerization. After synthesizing a methyl methacrylate / methacrylic acid / styrene copolymer (weight ratio 30/40/30) in this way, add 40 parts by weight of GMA, reprecipitate with purified water, filter, and dry to obtain an acrylic copolymer (AC-1) with a weight average molecular weight (Mw) of 30,000 and an acid value of 110 (mgKOH / g).

<Synthesis of Photosensitizer (B-1)>
Under a dry nitrogen stream, 21.22 g (0.05 mol) of TrisP-PA (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) and 36.27 g (0.135 mol) of 5-naphthoquinone diazide sulfonyl chloride were dissolved in 450 g of 1,4-dioxane and brought to room temperature. 15.18 g of triethylamine mixed with 50 g of 1,4-dioxane was added dropwise so that the temperature in the system did not exceed 35°C. After the dropwise addition, the mixture was stirred at 30°C for 2 hours. The triethylamine salt was filtered, and the filtrate was poured into water. The precipitate was then collected by filtration. The precipitate was dried in a vacuum dryer to obtain a photosensitizer (B-1) which is a quinone diazide compound represented by the following formula.

<Preparation of photosensitive resin composition R-1>
Under a yellow light, (A) PI-1 (10.0 g) as an alkali-soluble resin having an acidic group, (B) B-1 (1.2 g) as a photosensitizer, and (C) PGME (32.0 g) as an organic solvent. 0g) and GBL (8.0g). Thereafter, the obtained solution was filtered through a 0.45 μmφ filter to obtain a positive photosensitive resin composition R-1.

<Preparation of pigment dispersion 1>
30.00 g of Pigment Dispersant 1 was added to 770.00 g of PGMEA as a solvent and stirred for 5 minutes, and then 100.00 g of ZCR-1569H was added and stirred for 30 minutes. Furthermore, after adding 100.00 g of S0100CF as component (b), the mixture was stirred for 30 minutes to obtain a pre-stirred liquid. Filled with 0.4 mmφ composite oxide grinding media (zirconium oxide: hafnium oxide: yttrium oxide: aluminum oxide = weight ratio 93.3:1.5:4.9:0.3, manufactured by Toray Industries, Inc.) The pre-stirred liquid was sent to a vertical bead mill filled in a vessel at a rate of 75% by volume, and the first wet media dispersion treatment was performed in a circulation manner at a circumferential speed of 8 m/s for 3 hours. Furthermore, a grinding media made of a composite oxide with a diameter of 0.05 mm (zirconium oxide: hafnium oxide: yttrium oxide: aluminum oxide = weight ratio 93.3:1.5:4.9:0.3, manufactured by Toray Industries, Inc.) The liquid was sent to a vertical bead mill filled in a vessel with a filling rate of 75% by volume, and after performing a second wet media dispersion treatment using a circulation method at a circumferential speed of 9 m/s for 6 hours, it was passed through a filter with a diameter of 0.8 μm. filtration was performed to prepare pigment dispersion 1 having a solid content of 20.00% by weight.

<Preparation of photosensitive resin composition R-2>
Under a yellow light, 0.38 g of OXE03 was added as a photopolymerization initiator into a mixed solvent of 8.50 g of MBA and 16.16 g of PGMEA, and dissolved by stirring for 10 minutes. Thereto, 1.88 g of MEK-ST-40 was added as component (a), which is a silica particle dispersion, and dissolved by stirring for 10 minutes. 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 liquid mixture. Ta. 16.69 g of Pigment Dispersion 1 was mixed with this mixture and stirred for 30 minutes to prepare a negative photosensitive resin composition R-2 having a solid content of 15.00% by weight.

<Preparation of photosensitive resin composition R-3>
Similarly to the preparation of R-2, a black negative photosensitive resin composition R-3 was prepared using OSCAL-1421 in place of MEK-ST-40.

<Preparation of Photosensitive Resin Composition R-4>
A black negative photosensitive resin composition R-4 was prepared in the same manner as in the preparation of R-2, except that MEK-ST-L was used instead of MEK-ST-40.

<Preparation of photosensitive resin composition R-5>
Under a yellow light, (A) PIP-1 (10.0 g) as an alkali-soluble resin having an acidic group, (B) B-1 (1.2 g) as a photosensitizer, and (C) PGME (32.0 g) as an organic solvent. 0g) and GBL (8.0g). Thereafter, the obtained solution was filtered through a 0.45 μmφ filter to obtain a positive photosensitive resin composition R-5.

<Preparation of Pigment Dispersion 2>
200 g of zirconium nitride particles (ZrN, manufactured by Nisshin Engineering Co., Ltd.) produced by a thermal plasma method, 50 g of polyimide precursor resin (PIP-1), and 1000 g of γ-butyrolactone (GBL) were charged into a tank and stirred with a homomixer for 20 minutes to obtain a preliminary dispersion. The preliminary dispersion obtained was fed into a dispersing machine (Ultra Apex Mill, manufactured by Hiroshima Metal & Machinery Co., Ltd.) equipped with a centrifugal separator filled with 75% by volume of 0.05 mmφ zirconia beads, and dispersion was performed for 3 hours at a rotation speed of 10 m/s to obtain pigment dispersion 2 with a solid concentration of 20% by weight and a colorant/resin (weight ratio) of 80/20.

<Preparation of photosensitive resin composition R-6>
93.8 g of pigment dispersion 2, 50.5 g of alkali-soluble resin (PIP-1), 17.0 g of quinonediazide compound (B-1) as a photoacid generator, and phenol compound (bisphenol AF (Tokyo Kasei Kogyo)) Co., Ltd.)), 0.2 g of silicone surfactant (BYK-333), 105.0 g of GBL, and 720.0 g of PGME to give a total solid concentration of 10% by weight, pigment/ A black positive type photosensitive resin composition R-6 having a resin (weight ratio) of 15/85 was obtained.

<Preparation of Pigment Dispersion 3>
600g of IrgaphorBlack S0100CF (manufactured by BASF) as a colorant, 468.5g of a 20% by weight PGMEA solution of acrylic copolymer (AC-1) as an alkali-soluble resin, 56.3g of pigment dispersant 2 with an amine value of 20mgKOH/g as a polymer dispersant, and 1,875.2g of PGMEA were charged in a tank and stirred for 20 minutes with a homomixer to obtain a preliminary dispersion. The obtained preliminary dispersion was supplied to a dispersing machine Ultra Apex Mill manufactured by Hiroshima Metal & Machinery Co., Ltd. equipped with a centrifugal separator filled with 70% by volume of 0.10mmφ zirconia beads, and dispersion was performed for 3 hours at a rotation speed of 10m/s to obtain a pigment dispersion 3 with a solid concentration of 25% by weight and a colorant/resin (by weight) of 80/20.

<Synthesis of radical polymerizable compound FA-1)
In a 1L separable flask, 45 g (0.25 mol, manufactured by Osaka Gas Chemicals Co., Ltd.), 138 g (1 mol) of ethylene glycol mono(2-naphthyl)ether, and 1 g of 3-mercaptopropionic acid were added, and then heated to 60°C to completely dissolve. Then, 54 g of sulfuric acid was gradually added, and the mixture was stirred for 5 hours while maintaining the temperature at 60°C. It was confirmed by HPLC that the conversion rate of 9-fluorenone was 99% or more. After neutralizing the reaction liquid obtained by adding 48% caustic soda water, 400 g of xylene was added, and the mixture was washed several times with distilled water and cooled to precipitate crystals. After further filtering and drying, the target 9,9-bis[6-(2-hydroxyethoxy)-2-naphthyl]fluorene was obtained as 82 g (yield 75%) of crystals. When the HPLC purity of the obtained crystals was measured, 87 g (yield 67%) of the target product with a purity of 98.3% was obtained. ^{The 1} H-NMR and mass spectrum of the obtained sample confirmed that it was the target 9,9-bis[6-(2-hydroxyethoxy)-2-naphthyl]fluorene. The ethylene glycol mono(2-naphthyl)ether used was one (purity 99% or more) purified from the reaction mixture obtained by reacting 2-naphthol with ethylene carbonate.

43.8 g (0.1 mol) of the 9,9-bis[6-(2-hydroxyethoxy)-2-naphthyl]fluorene thus obtained, 18.7 g (2.6 mol) of acrylic acid, 2.2 g of p-toluenesulfonic acid, 98 g of toluene, and 0.21 g of methoquinone were charged and subjected to a dehydration esterification reaction while refluxing at 110°C to 115°C until the theoretical amount of dehydration was obtained. The reaction liquid was then neutralized with an alkali and washed with 20% saline. After washing, the toluene was removed. In this way, compound FA-1 was obtained.

<Synthesis of radical polymerizable compound FA-2>
A 1 L glass vessel equipped with a stirrer, a cooler, and a thermometer was charged with 36 g of fluorenone with a purity of 99%, 138.40 g of β-naphthol, 7 ml of β-mercaptopropionic acid, and 180 g of toluene, and then 17.3 ml of 98% sulfuric acid was further charged and the reaction was carried out by stirring for 6 hours at 60° C. The reaction product (reaction liquid) after stirring for 6 hours was confirmed by HPLC, and the remaining amount of fluorenone was found to be 0.1% or less.

After adding 230 g of toluene and 70 g of water to the obtained reaction solution, a 1N (normal) aqueous sodium hydroxide solution was added to neutralize the solution until the pH reached about 7, and then the aqueous layer was removed. After heating the organic layer to 80° C., it was washed five times with 80 g of water.

After adding diisopropyl ether to the organic layer and stirring at 60°C for 1 hour, the desired product, 9,9-bis(6-hydroxy- 89.8 g of 2-naphthyl)fluorene (hereinafter sometimes referred to as BNF) was obtained in a yield of 90.0%.

Next, as another synthesis, sodium acrylate (47.1 g, 0.50 mol, manufactured by Aldrich), epichlorohydrin (209 g, 2.26 mol, manufactured by Nacalai Tesque), tetramemethyl Ammonium chloride (0.58 g, 5.31 mmol, manufactured by Nacalai Tesque Co., Ltd.) and hydroquinone (0.303 g, 2.75 mmol, manufactured by Nacalai Tesque Co., Ltd.) were added and stirred at 90° C. for 3 hours. After the reaction, the reaction solution was cooled to room temperature, added with pure water (70 mL), and extracted with toluene (50 mL x 3). The solvent was removed from this extract to obtain a brown liquid (26.4 g, crude yield 41%). This brown liquid was distilled under reduced pressure (35-40° C./4 mmHg) to obtain glycidyl acrylate (colorless transparent solution, 17.3 g, yield 27%, purity 100%).

Furthermore, the reaction of BNF with glycidyl acrylate was carried out as follows. The reaction was carried out by placing BNF (1.80 g, 4.00 mmol), glycidyl acrylate (1.12 g, 8.76 mmol), hydroquinone (7.1 mg, 0.064 mmol, Nacalai Tesque, Inc.), and tributylamine (31.6 mg, 0.170 mmol) in a 50 mL beaker and stirring at 90-100°C for 2 hours to obtain compound FA-2.

<Preparation of Photosensitive Resin Composition R-7>
To 250.0 g of the pigment dispersion 3, 386.5 g of a 20 wt % PGMEA solution of acrylic copolymer (AC-1) as an alkali-soluble resin, 13.3 g of "ADEKA ARCLES" (registered trademark) NCI-831 as a photopolymerization initiator, 4.7 g of FA-1 and 42.0 g of DPCA-60 as radical polymerizable compounds, 0.2 g of silicone-based surfactant "BYK" (registered trademark) 333 (manufactured by BYK-Chemie Co., Ltd.), and 490.8 g of PGMEA were added to obtain a black negative photosensitive resin composition R-7 having a total solids concentration of 20 wt % and a color pigment/resin (weight ratio) of 25/75.

<Preparation of photosensitive resin composition R-8>
In the same manner as in the preparation of R-7, a black negative photosensitive resin composition was obtained by using 4.7 g of FA-2 and 42.0 g of DPCA-60 instead of FA-1 as radically polymerizable compounds. R-8 was obtained.

<Examples 1 to 28, Comparative Examples 1 to 5>
In each example and comparative example, the following organic EL display devices were manufactured, and the structure of the dam part, observation of the taper of the dam part, the film thickness of the pixel division part and the level difference of the dam part, the top of the pixel division part and the taper of the dam part were observed. The thickness of the metal doped layer on the surface, silica particles in the pixel division layer, driving voltage test, electrical reliability, and bending reliability were evaluated.

First, as a first electrode, amorphous ITO (10 nm), AgPdCu alloy (100 nm), and amorphous ITO (10 nm) were sequentially formed into films by vacuum sputtering on the center of a 100 mm x 100 mm PET substrate, with line widths of 60 μm and 100 μm. It was etched into 100 stripes with a pitch and length of 10 mm. That is, the exposed portion of the base material has a width of 40 μm.

Furthermore, a photosensitive resin composition for the pixel division part according to each example and comparative example shown in Table 1 was applied by spin coating, and then prebaked for 2 minutes on a hot plate at 100°C to form a film. did.

After exposing this film to UV light through a striped pattern photomask, it was developed with a 2.38% TMAH aqueous solution, and if it was a negative type, only the unexposed areas were dissolved, and if it was a positive type, only the exposed areas were dissolved. Afterwards, it was rinsed with pure water to obtain a striped pattern. The pattern was made in the form of a stripe, with 101 lines having a line width of 60 μm, a pitch of 100 μm, and a length of 10 mm, aligned with the center of the exposed portion of the first electrode.

In addition, a dam section with a width of 20 μm was formed in the center of the line width of 60 μm, and in order to make pixel opening 40 μm, pixel division section 20 μm, dam section 20 μm, and pixel division section 20 μm into repeating units, the following specific processing was performed. In the case of a dam section with a convex structure, a 20 μm wide insulating layer was prepared in a stripe shape similar to the pixel division section. In addition, in the case of a dam section with a concave structure, a 20 μm wide insulating layer was appropriately removed by etching and an insulating layer was prepared. In this way, a substrate was obtained with a striped first electrode with a pixel opening 40 μm, pixel division section 20 μm, dam section 20 μm, and pixel division section 20 μm as repeating units. The film thickness removed by etching as the dam section and the photosensitive resin composition that became the cured film are shown in Table 1.

Then, the substrate was cured for 60 minutes in an oven at 250°C in a nitrogen atmosphere to obtain a patterned substrate including a pixel division section and a dam section. The film thickness of the pixel division section and the structure and step of the dam section were adjusted by adjusting the coating conditions by spin coating, the photolithography processing conditions, the etching conditions, the curing conditions, etc. The structure and step of the dam section of the final substrate are shown in Table 1. In Comparative Examples 3 and 4, no uneven structure was obtained by not etching the area where the dam section should be provided or by not coating an insulating layer, and as a result, no dam structure was obtained. Furthermore, the measurement results of the surface roughness of the pixel division section and the dam section are also shown in Table 1.

The substrate thus obtained was ultrasonically cleaned for 15 minutes using "Semicoclean" (registered trademark) 56 (manufactured by Furuuchi Chemical Co., Ltd.), and then washed with ultrapure water. Immediately before forming the organic EL layer, the substrate was subjected to UV-ozone treatment for 1 hour, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum inside the apparatus was 1 x 10-3 Pa or less.

Next, the next organic EL layer was formed on the entire surface of this patterned substrate by vacuum evaporation. The degree of vacuum during vapor deposition was 1×10 ⁻³ Pa or less, and the substrate was rotated with respect to the vapor deposition source during vapor deposition. Using a resistance heating method, HAT-CN6 was first deposited to a thickness of 5 nm as a hole injection layer, and then HT-1 was deposited to a thickness of 50 nm as a hole transport layer. Next, as a light-emitting layer, a mixed layer of host material H-1 and dopant material D-1 was deposited to a thickness of 20 nm at a doping concentration of 5% by weight. Next, a metal doped layer was used as an electron transport layer, and was deposited to a thickness of 20 nm so that the deposition rate ratio was host material:dopant material = 99:1. Table 2 shows the combinations of the host material and dopant material of the metal doped layer in each Example and Comparative Example, and the host materials are shown below.

Incidentally, HAT-CN ₆ , HT-1, H-1 and D-1 are the compounds shown below.

Furthermore, 20 stripe-shaped second electrodes, each 400 μm wide, 500 μm pitch, and 10 mm long, were deposited to a thickness of 10 nm by vapor deposition of Mg and Ag at a volume ratio of 10:1 so as to intersect with the first electrodes. Note that the film thickness referred to here is the value displayed on a quartz crystal oscillator film thickness monitor.

In this way, an organic EL display device was completed that had 100 first electrodes, 20 second electrodes, and 200 light-emitting elements where these electrodes intersect. A schematic diagram of the organic EL display device of this embodiment is shown in Figure 18.

Then, the taper of the dam section was observed, and the thickness of the metal-doped layer on the pixel division section and on the tapered surface of the dam section was measured. The results are shown in Table 3. In addition, a driving voltage test, an electrical reliability test, and a bending reliability test were performed on the organic EL display device.

The results are shown in Table 4. In Comparative Examples 1, 2, 3, and 5, there was no dopant material in the electron transport layer, that is, there was no metal doping.

Furthermore, the cross-sectional analysis results for Examples 1 to 9, 22, 25, and 27 to 28, in which component (a) was present in each Example and Comparative Example, are shown in Table 5.

The organic EL display device of the present invention can be used as an organic EL display device that is driven at low voltage, has small leakage current, and has high folding reliability.

1 Base material 1a Base material base 2 First electrode 3 Pixel opening 4 Pixel dividing portion 5 Dam portion 6 Organic EL layer 7 Second electrode 8 TFT
9 Flattening layer 10 Sealing layer 11 Polarizing layer 12 Ultraviolet absorption layer 13 Cylinder 14 Organic EL display device

Claims (13)

An organic EL display device having a substrate having a first electrode and a pixel division layer on a base material, an organic EL layer, and a second electrode, the pixel division layer including a pixel opening, a pixel division portion, and a dam portion, and the organic EL layer including an alkali metal doped layer and/or a rare earth metal doped layer. 2. The alkali metal doped layer and/or the rare earth metal doped layer contains a compound having one or more skeletons selected from the group consisting of a phenanthroline skeleton, a triazine skeleton, a bipyridine skeleton, a terpyridine skeleton, and a phosphine oxide skeleton. Organic EL display device. The organic EL display device according to claim 1, wherein the alkali metal doped layer and/or the rare earth metal doped layer contains a compound having a phenanthroline skeleton. The organic EL display device according to claim 1, wherein the alkali metal-doped layer and/or the rare earth metal-doped layer contains a compound having a phenanthroline skeleton polymer. The organic EL display device according to claim 1, wherein the alkali metal doped layer and/or the rare earth metal doped layer contains a compound having a terpyridine skeleton. The organic EL display device according to claim 1, wherein the dam portion has a convex structure. The organic EL display device according to claim 1, wherein the dam portion has a concave structure. The organic EL display device according to claim 6 or 7, wherein the dam portion has a taper angle of 91 to 120°. The organic EL display device according to claim 6 or 7, wherein the dam portion has a taper angle of 50 to 90°. According to claim 9, the thickness of the alkali metal doped layer and/or rare earth metal doped layer on the tapered surface of the dam portion is 0.5 nm or more and 0.5 times or less of the thickness in the pixel dividing portion. The organic EL display device described above. The organic EL display device according to claim 1, wherein the pixel dividing portion has a surface roughness Ra1 of 0.1 nm or more and 20 nm or less. The organic EL display device according to claim 1, wherein the top surface of the dam portion having a convex structure and/or the bottom surface of the dam portion having a concave structure has a surface roughness Ra2 of 5 nm or more and 50 nm or less. The organic EL display device according to claim 1, wherein the pixel division layer contains silica particles having a primary particle diameter of 5 to 30 nm.

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