WO2022163199A1 - Organic electroluminescent element, method for producing same, lighting device provided with same, display device and printed model - Google Patents

Organic electroluminescent element, method for producing same, lighting device provided with same, display device and printed model Download PDF

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WO2022163199A1
WO2022163199A1 PCT/JP2021/046667 JP2021046667W WO2022163199A1 WO 2022163199 A1 WO2022163199 A1 WO 2022163199A1 JP 2021046667 W JP2021046667 W JP 2021046667W WO 2022163199 A1 WO2022163199 A1 WO 2022163199A1
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light
organic
emitting layer
layer
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Japanese (ja)
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和博 及川
倫生 泉
秀雄 ▲高▼
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コニカミノルタ株式会社
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/10—Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]

Definitions

  • the present invention relates to an organic electroluminescence element, a method for manufacturing the same, and a lighting device, a display device, and a printed product having the same. More specifically, it relates to an organic electroluminescence element or the like that has high luminous efficiency, has a long life, can suppress deterioration in performance during manufacturing in the atmosphere, and can be manufactured at low cost.
  • An organic electroluminescent device (or diode; also referred to as an "organic EL element”) has a structure in which a layer containing a light-emitting compound is sandwiched between a cathode and an anode. It is a device that utilizes the recombination of the holes injected from the cathode and the electrons injected from the cathode to generate excitons, and the emission of light (electromagnetic waves) when the excitons are deactivated.
  • organic electroluminescence elements As the attractiveness of organic electroluminescence elements as surface light sources increases, there is a need for organic EL elements with performance that satisfies all of higher efficiency, longer life, and lower cost.
  • the vapor deposition method has a problem of high manufacturing cost due to the low efficiency of manufacturing equipment and materials used to achieve a high degree of vacuum.
  • the vapor deposition method has a limit on the number of materials to be mixed, and it is necessary to layer the layers while separating the functions by changing the material for each layer.
  • Non-Patent Document 1 discloses an example of an organic EL display device in which a multi-color pixel is realized by injecting a polymer light-emitting material into an insulating bank by inkjet printing.
  • the above-mentioned manufacturing method of the display device represented by the organic EL display device requires pre-formation of the bank and advanced alignment technology. did not meet expectations.
  • Non-Patent Document 2 discloses an organic EL device in which dots of 200 ⁇ m are patterned by an inkjet printing method without prior formation of banks.
  • PMMA polymethyl methacrylate
  • a host compound and a light-emitting material are printed using inkjet printing on the image area of the receiving layer.
  • the conductive luminescent material is injected and mixed with the insulating non-image area formed only by the receiving layer.
  • a phosphorescent compound such as Ir(ppy) 3 , which can be expected to have an external quantum efficiency of about 20%, is usually used, but the external quantum efficiency of the light-emitting part remains at about 3.1%. Further improvements were needed.
  • the present invention has been made in view of the above problems and circumstances, and the problem to be solved is that the luminous efficiency is high, the life is long, and the deterioration of performance during manufacturing in the atmosphere can be suppressed, and the cost is low. It is an object of the present invention to provide an organic electroluminescence element that can be manufactured by the method, a method for manufacturing the same, and an illumination device, a display device, and a printed product having the same.
  • the present inventors have investigated the causes of the above problems and found that the charge-transporting host compound, the luminescent dopant, the polymer, etc. contained in the light-emitting layer can improve the hole mobility and the electron mobility.
  • the inventors have found that the above object can be achieved by controlling the difference between the common logarithms, and have completed the present invention. That is, the above problems related to the present invention are solved by the following means.
  • An organic electroluminescence element having an image display portion sandwiched between an anode and a cathode facing each other on at least a substrate, wherein the image display section is composed of a luminescent image display section and a non-luminescent image display section,
  • the light-emitting image display section has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer,
  • the light-emitting layer contains at least a polymer having a conductivity of 1 [S/m] or less, a charge-transporting host compound, and a light-emitting dopant, and
  • An organic electroluminescence device wherein the absolute value of the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is 4.5 or less.
  • a method for producing an organic electroluminescence device for producing the organic electroluminescence device according to any one of items 1 to 13, A method for producing an organic electroluminescence device, comprising a step of forming the light-emitting layer by an inkjet printing method.
  • Item 14 The method for producing an organic electroluminescence element according to Item 14, comprising a step of forming the light-emitting layer by an inkjet printing method in the atmosphere.
  • a lighting device comprising the organic electroluminescence element according to any one of items 1 to 13.
  • a display device comprising the organic electroluminescence element according to any one of items 1 to 13.
  • a printed modeled article comprising the organic electroluminescence element according to any one of items 1 to 13.
  • an organic electroluminescent element that has high luminous efficiency, has a long life, can suppress performance deterioration during manufacturing in the atmosphere, and can be manufactured at low cost, and a method for manufacturing the same. and a lighting device, a display device, and a printed product having the same.
  • the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is controlled to a specific value or less by using a charge-transporting host compound, a light-emitting dopant, a polymer, or the like contained in the light-emitting layer. It is presumed that the problem was solved.
  • the following explanation considers the manifestation mechanism of the effect obtained by controlling the difference between the hole mobility and the electron mobility, and is not necessarily clear. Therefore, the expression mechanism of the effect of the present invention is not limited to the speculated mechanism below.
  • the polymer When an ordinary insulating polymer such as polymethyl methacrylate (PMMA) is used in the light-emitting layer of an organic EL element, the polymer mainly disperses or agglomerates in the layer, suppressing current flow. or the route (conductive path) is blocked. In addition, the charge-transporting host compound and the light-emitting dopant aggregate in the form of being extruded into the polymer, causing a decrease in conductivity, interfacial recombination, and a decrease in recombination probability.
  • PMMA polymethyl methacrylate
  • polymer having a conductivity of 1 [S/m] or less (hereinafter also simply referred to as "polymer”) is localized at the interface between adjacent layers, thereby exhibiting carrier balance and various block properties. It has been suggested.
  • the above polymer has the effect of dispersing the host compound and the dopant, and has the effect of suppressing the trapping of charge carriers traveling between these molecules at the grain boundary, and the effect of suppressing the trapping of these carriers. It is possible to achieve compatibility with the carrier block effect that suppresses penetration of the light-emitting layer.
  • the light-emitting material is oxidized during operation and becomes a light emission quencher (also referred to as a "quencher"), and the polymer has a high probability of occurrence. It has the highest effect of suppressing recombination at the light-emitting layer interface. In particular, the effect is significant when the absolute value of the difference between the common logarithms of hole mobility and electron mobility is 4.5 or less, localized near the interface between the light-emitting layer and the adjacent layer.
  • the effect of the present invention is likely to be exhibited when the light-emitting layer is formed by a droplet discharge method such as inkjet.
  • a droplet discharge method such as inkjet.
  • the effect of the active gas in the film formation atmosphere is more pronounced than when the film is formed by vapor deposition or spin coating, and the effect of lowering the luminous efficiency and shortening the life is reduced.
  • the film is formed by vapor deposition or spin coating, and the effect of lowering the luminous efficiency and shortening the life is reduced.
  • it still emits light without performance degradation in such cases. Therefore, manufacturing costs for inert gas and vacuum equipment can also be reduced.
  • Schematic cross-sectional view of the organic EL element of the present invention Conceptual diagram showing that light-emitting image display units are arranged in dots.
  • Sectional view showing an example of a partition (bank) Conceptual diagram showing a method for fabricating an organic EL element using an inkjet recording method
  • the organic electroluminescence element of the present invention is an organic electroluminescence element having, on at least a substrate, an image display portion sandwiched between an anode and a cathode facing each other, wherein the image display portion comprises a light-emitting image display portion and a non-light-emitting portion.
  • the light-emitting image display portion has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer, and the light-emitting layer has an electrical conductivity of at least 1 [S/m] or less.
  • This feature is a technical feature common to or corresponding to each of the following embodiments (forms).
  • the absolute value of the difference between the common logarithm of the hole mobility and the electron mobility of the light emitting layer is 3.5 or less, and the conductivity is at least 1 [S / m] or less. It is preferable from the viewpoint of maximizing the blocking function of the polymer, improving the recombination probability and driving life, and suppressing the influence during production in the atmosphere. More preferably, it is 2.5 or less.
  • the mass ratio of the polymer is in the range of 5 to 80% by mass when the total mass of the light-emitting layer is 100.
  • the polymer prefferably be a polymer containing a benzene ring, because it is easy to obtain the effects of increasing the film density and dispersing the carrier transport material and dopant.
  • the polymer containing the benzene ring is a non-conjugated polymer from the viewpoint of carrier blocking.
  • a layer it is preferable in terms of retaining the charge in the emitted light and increasing the recombination probability.
  • the non-conjugated polymer contains a benzene ring as a side chain in terms of the effects of increasing the density and dispersing the carrier transport material and the dopant.
  • the non-conjugated polymer is polystyrene from the viewpoint of suppressing recombination at the interface on both electrode sides.
  • the non-conjugated polymer is a polystyrene derivative from the viewpoint of suppressing recombination at the interface on both electrode sides.
  • the polystyrene derivative is polyvinyl phenol from the viewpoint of suppressing recombination at the interface on both electrode sides.
  • the non-conjugated polymer is a mixture of components with different stereoregularities in that the amount of polymer localized at the interface can be controlled and the carrier balance can be adjusted.
  • the light-emitting layer prefferably be directly adjacent to the charge injection layer or the electrode in terms of controlling the mobility of charge carriers.
  • the method for producing an organic electroluminescence element of the present invention is characterized by being a method of a mode having a step of forming the light-emitting layer by an inkjet printing method. Moreover, it is more preferable to have a step of forming the light-emitting layer by an inkjet printing method in the atmosphere.
  • the organic electroluminescence device of the present invention has various characteristics as described above, it can be suitably used for lighting devices, display devices, and printed objects.
  • An organic electroluminescence device (hereinafter referred to as an "organic EL device") of the present invention is an organic electroluminescence device having, on at least a substrate, an image display portion sandwiched between an anode and a cathode facing each other, wherein the image
  • the display section is composed of a light-emitting image display section and a non-light-emitting image display section, the light-emitting image display section has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer, and the light-emitting layer comprises at least
  • the light-emitting layer contains a polymer having a conductivity of 1 [S/m] or less, a charge-transporting host compound, and a light-emitting dopant, and the absolute value of the difference between the common logarithms of hole mobility and electron mobility of the light-emitting layer is , 4.5 or less.
  • the absolute value of the difference between the common logarithm of the hole mobility and the electron mobility of the light-emitting layer is 3.5 or less, making the most of the blocking function of the polymer and recombination It is preferable from the viewpoint of improving the probability and driving life and suppressing the influence during manufacturing in the atmosphere. More preferably, it is 2.5 or less.
  • conductivity also referred to as “electrical conductivity” or “electrical conductivity” refers to a value that is an indicator of how easily electricity can pass, and the reciprocal of electrical resistivity is the SI system The unit is S/m (siemens per meter).
  • Electron and hole mobility refers to a measure of the ease with which charge carriers, ie, electrons and holes, can move through a material in response to an electric field.
  • a method for measuring and evaluating the mobility of electrons and holes for example, a method of determining from the current-voltage characteristics of the space charge limited current, or a method of irradiating a predetermined element with pulsed light and moving the carriers from the time it takes to travel between the electrodes
  • There is an evaluation method by the Time-Of-Fight method for obtaining mobility or an evaluation method by impedance spectroscopy for obtaining mobility from the transit time effect when an AC voltage is applied to an organic EL element.
  • the electron and hole mobilities are measured as follows. That is, as a sample for measurement, an organic EL device composed of a laminate sandwiching a light-emitting layer containing at least an electron-transporting compound or a hole-transporting compound to be measured between an anode and a cathode is prepared. Next, calculate the electron mobility and hole mobility based on the graph obtained by plotting the measured values of the current density-voltage characteristics (“JV characteristics”) of each organic EL element produced and the following theoretical formula. do.
  • JV characteristics current density-voltage characteristics
  • Non-Patent Document MA Lampert, P. Mark, Current injection in solids Academic, New York, 1970
  • International Publication No. 2019/039174 You can refer to it. Concrete examples will be described in the description of the examples below.
  • the graph of the current density-voltage characteristics has a pattern similar to that of the space charge limited current. Furthermore, the absolute value of the difference between those common logarithms is calculated.
  • J (9/8) ⁇ 0 ⁇ (V 2 /L 3 )
  • ⁇ the dielectric constant of the organic thin film
  • ⁇ 0 the vacuum dielectric constant
  • ⁇ the carrier mobility
  • J the current density
  • V the applied voltage.
  • a graph of JV 2 is created by plotting the measured values of J and V 2 , and the slope of the tangent line to the quadratic curve Calculate the electron mobility ⁇ e and hole mobility ⁇ h of each organic EL device from a, and the difference between the common logarithmic values of each organic EL device (log [electron mobility] ⁇ log [hole mobility]), That is, the absolute value of log([electron mobility]/[hole mobility]), which is the common logarithm of the ratio of [electron mobility] to [hole mobility], is obtained.
  • the dielectric constant is 3, and it is assumed that it is not affected by the electric field. This is the mobility when Note that when attention is paid to the difference in mobility as in the present invention, there is no need to discuss the dielectric constant, so the discussion will be omitted.
  • the organic electroluminescence device of the present invention (hereinafter also referred to as “organic EL device”) has an image display portion sandwiched between an anode and a cathode facing each other on a substrate.
  • the image display section is composed of a light-emitting image display section having a light-emitting layer and a non-light-emitting image display section.
  • the light-emitting image display section may have a charge injection layer and a charge transport layer in addition to the light-emitting layer. A small number of layers is preferable, and the charge injection layer and the charge transport layer may be omitted.
  • the organic EL element of the present invention refers to an organic EL element in a broad sense including a non-luminous image display portion.
  • the organic EL device of the present invention can take various forms/configurations.
  • the method and format for extracting light is a bottom emission type that extracts light from the substrate side.
  • the image display part When viewed from the substrate side, an image is displayed, and the part where the image is displayed (including planar and three-dimensional structures) is called an "image display part".
  • the “luminescence image display section” of the image display section according to the present invention refers to individual dots themselves and aggregates thereof shown in FIG.
  • the light-emitting pixel is composed of a functional layer such as a "light-emitting layer” sandwiched between common electrodes.
  • the "light-emitting pixel” is a minimum element that expresses color information (color tone and gradation) by emitting light.
  • the "light-emitting pixels” are also referred to as “light-emitting dots", “dot light-emitting images”, or simply “dots”.
  • the light-emitting image display unit according to the present invention may be formed by dots or a solid pattern on a planar substrate, may be formed by a three-dimensional structure formed on the surface of a curved substrate, an elastic substrate, or the like, or may be formed by a sheet.
  • a bank material or a sealing material may be embedded in a three-dimensional structure other than the shape material.
  • the luminous pixels are partitioned by a partition structure that is a non-luminous image display portion, and the partition is preferably an insulating layer.
  • the light-emitting layer according to the present invention is formed in dots, it is desirable that patterning is possible.
  • a printing method using a mask having patterning openings may be used, but a non-contact method is preferable from the viewpoint of less damage to the non-light-emitting layer.
  • the dispenser method or the inkjet printing method is more preferable from the viewpoint of enabling high resolution.
  • the size of the dots is preferably within the range of 30 to 300 ⁇ m as a circle-equivalent particle size when measured based on an optical microscope photograph (plan view) taken from the main light-emitting surface side of the light-emitting layer.
  • FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element that constitutes a light-emitting image display section according to the present invention.
  • the organic EL element 10 includes a substrate 11, an anode 12, a hole injection layer 13, a hole transport layer 14, a light emitting layer 15, an electron transport layer 16, an electron injection layer 17 and a cathode 18 in this order.
  • the light-emitting layer 15 contains a common host compound, and the blue (B) light-emitting pixel 21, the green (G) light-emitting pixel 22 and the red (R) light-emitting pixel are arranged between the insulating layers (banks) 2.
  • the organic EL element 10 having 23 is obtained.
  • the layer from the hole injection layer to the electron injection layer is also called an "organic functional layer".
  • FIG. 2 is a conceptual diagram showing that narrowly-defined organic EL elements forming light-emitting pixels are arranged in dots in a light-emitting image display section according to the present invention. That is, FIG. 2 is a conceptual diagram (plan view) of the image display unit viewed from the viewing side. In FIG. 2, portions indicated by black dots are “luminous image display portions”, and other white portions are “non-luminous image display portions”.
  • the dots are preferably formed and arranged as minute pixels that cannot be visually recognized as dots when the image on the image display device is observed by a normal visual observation method.
  • portions other than dots are non-luminous image display portions.
  • a non-light-emitting image display portion does not contribute to light emission unless it has a light-emitting layer. That is, since it is non-luminous, in the light-emitting image display portion, an insulating layer may be used instead of the light-emitting layer, and other layer configurations may be the same.
  • the non-light-emitting image display portion does not need to have elements that contribute to the expression of light-emitting properties, but by using the same layer as the light-emitting image display portion for the layers other than the light-emitting layer, the non-light-emitting image display portion can be formed by uniform coating or the like. , easy to manufacture. Also, by using an insulating layer instead of the light-emitting layer, it is possible to prevent electrons and holes, ie charge carriers, from entering.
  • a charge injection layer according to the present invention refers to a hole injection layer and an electron injection layer
  • a charge transport layer refers to a hole transport layer and an electron transport layer.
  • Anode/light-emitting layer/cathode (2) Anode/hole-transporting layer/light-emitting layer/cathode (3) Anode/hole-transporting layer/light-emitting layer/electron-transporting layer/cathode (4) Anode/hole-transporting layer /light emitting layer/electron transport layer/electron injection layer/cathode (5) anode/hole injection layer/light emitting layer/electron transport layer/cathode (6) anode/hole injection layer/hole transport layer/light emitting layer/electron injection layer/cathode (7) anode/hole injection layer/light emitting layer/electron injection layer/cathode (8) anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/cathode (9) anode/ Hole injection layer/hole transport layer/luminescent layer/electron transport layer/electron injection layer/cathode
  • the light-emitting layer is directly adjacent to the charge injection layer or directly adjacent to the electrode from the viewpoint of controlling the mobility of charge carriers.
  • the light-emitting layer is a layer that provides a field for recombination of electrons and holes injected from an electrode or an adjacent layer to emit light via excitons.
  • the light-emitting layer is composed of a single layer or multiple layers. That is, the organic EL element is an element using an organic light-emitting material that emits light when a voltage is applied. By applying a voltage, electrons and holes recombine in the light-emitting layer, and the excitons (excitons) generated at this time are deactivated, and light (electromagnetic waves) emitted when returning to the ground state is used. It is.
  • the light-emitting layer according to the present invention includes at least a polymer having a conductivity of 1 [S/m] or less (also referred to as a "binder” or “host polymer”), a charge-transporting host compound (a "matrix material", or a “light-emitting host compound”).
  • the absolute value of the difference between the common logarithm of the hole mobility and the electron mobility of the light-emitting layer is 3.5 or less. It is preferable from the viewpoint of improving the bonding probability and driving life and suppressing the influence of manufacturing in the atmosphere. More preferably, it is 2.5 or less. From the viewpoint of controlling the mobility of holes and electrons, it is preferable that the mass ratio of the polymer is in the range of 5 to 80% when the total mass of the light-emitting layer is 100.
  • the polymer is localized at the electrode-side interface of the light-emitting layer.
  • an electrode is provided adjacent to the light emitting layer, other hole injection layer (anode buffer layer), hole transport layer, hole blocking layer (hole barrier layer), electron injection layer (cathode buffer layer), An electron-transporting layer, an electron-blocking layer (electron-blocking layer), and the like may be appropriately provided as layers constituting the organic EL element.
  • Each of these layers can be formed with known materials and methods as long as they satisfy the provisions of the present invention.
  • the light emitting layer is directly adjacent to the charge injection layer or directly adjacent to the electrode.
  • directly adjacent means that there is no functional layer between the light-emitting layer and the charge injection layer or electrode, and the layers are in direct contact with each other.
  • the "electrode-side interface of the light-emitting layer” refers to the interface of the light-emitting layer that is in contact with any functional layer including the anode or the cathode, which is on the electrode side of the light-emitting layer.
  • any functional layer including the anode or the cathode which is on the electrode side of the light-emitting layer.
  • Light emitting layer material Polymer materials used in the light-emitting layer can have various molecular weight distributions, depending on the physical properties of the ink and coating properties. Moreover, the material for the light-emitting layer that constitutes the light-emitting layer may be either a polymer or a low-molecular weight material. When the low-molecular-weight material is formed by coating, the dopant molecules are dispersed between the polymer chains to increase the luminous efficiency, which is preferable.
  • a compound with a molecular weight of 3000 or less may be used. By using a compound having a molecular weight of 3000 or less, the solubility in a solvent is improved. In addition, preferably, the molecular weight is 500 or more.
  • the molecular weights of the light-emitting dopant and the host compound used as light-emitting layer materials are not particularly limited. It is preferred to contain compounds that do not contain any radicals, alkenyl groups, alkynyl groups or arylalkyl groups.
  • the thickness of the light-emitting layer is not particularly limited, it is preferably 50 nm or more, more preferably 70 nm or more, from the viewpoint of the distance between the recombination region and the electron transport layer. Moreover, from the viewpoint of driving voltage, it is preferably 150 nm or less.
  • the method for forming the light-emitting layer is not particularly limited, but it is preferably formed by a wet method or the like because it contains a polymer. In this case, the manufacturing cost of the organic EL element can be reduced as compared with vacuum deposition or the like.
  • Wet methods include, for example, a spin coating method, a casting method, an inkjet printing method, a printing method, a die coating method, a blade coating method, a roll coating method, a dispenser method, a spray coating method, a curtain coating method, an LB method (Langmuir-Blodgett method, ) etc. can be used.
  • a method applicable to a roll-to-roll system such as a die coating method, a roll coating method, a dispenser method, and an inkjet printing method is preferable because a homogeneous thin film can be easily obtained and high productivity can be obtained.
  • the inkjet printing method will be described later.
  • the liquid medium for dissolving or dispersing the light emitting layer material includes, for example, alcohols such as isopropanol and tetrafluoropropanol, ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, chloroform, dichlorobenzene and the like.
  • Halogenated hydrocarbons aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, organic solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) can be used.
  • aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene
  • aliphatic hydrocarbons such as cyclohexane
  • decalin and dodecane organic solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) can be used.
  • organic solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO)
  • dispersing the light-emitting layer material in a liquid medium it can be dispersed by a dispersion method such as ultrasonic waves, high-shear force dispersion, or media dispersion.
  • the method of forming the light-emitting layer can be formed either in the atmosphere or under an inert gas.
  • the atmosphere the adsorption of the adsorbed active gas on the surface of the light-emitting layer is saturated, and the degree of atmospheric degradation is evened out, so there is also the advantage of suppressing variations in chromaticity and uneven light emission.
  • the polymer contained in the light-emitting layer according to the invention is characterized by having an electrical conductivity of 1 [S/m] or less.
  • conductivity also referred to as “electrical conductivity” or “electrical conductivity” refers to a value that is an index representing how easily electricity can pass, and the reciprocal of electrical resistivity is the SI unit is expressed as S/m (Siemens per meter).
  • a conductivity of 1 S/m or less facilitates controlling the movement of injected electrons and holes, ie charge carriers. More preferably, it has relatively low conductivity or insulation, with a conductivity of 10 ⁇ 8 S/m or less.
  • the electrical conductivity exceeds 1 S/m, the rate of charge transfer through the polymer becomes more rate-determining than the charge transfer to the host compound or dopant, and the recombination probability decreases.
  • the polymer is a polymer containing a benzene ring, from the viewpoint of easily obtaining the effects of increasing the film density and dispersing the carrier transport material and the dopant.
  • the polymer containing the benzene ring is a non-conjugated polymer from the viewpoint of carrier blocking. is preferable from the viewpoint of increasing the recombination probability by retaining the charge in the emitted light.
  • the non-conjugated polymer contains a benzene ring as a side chain from the viewpoint of the effect of increasing the density and dispersing the carrier transport material and the dopant.
  • the non-conjugated polymer is polystyrene.
  • the non-conjugated polymer is more preferably a polystyrene derivative.
  • the effect of the present invention is remarkable for polymers containing benzene rings.
  • the light-emitting layer material interacts with the light-emitting layer material containing many ⁇ It easily encapsulates molecules and forms a phase-separated structure to easily obtain a trap suppressing effect and a carrier blocking effect.
  • the polystyrene derivative is polyvinylphenol from the viewpoint of suppression of recombination at the interface between both electrodes.
  • a polar group-added benzene ring in the side chain like polyvinylphenol (PVPh)
  • PVPh polyvinylphenol
  • hydrogen bonds between polymers are formed, and the formation of a phase separation structure is promoted by heating during drying.
  • the film is densely formed by ⁇ - ⁇ interactions and hydrogen bonding, the carrier transport sites formed by hosts and dopants through similar interaction networks are also densified.
  • the non-conjugated polymer is a mixture of components with different stereoregularities from the viewpoint of controlling the amount of polymer localized at the interface and adjusting the carrier balance.
  • the polymer of the light-emitting layer can be appropriately selected from known materials and used.
  • Polyalkylenes such as polyethylene, polypropylene, polyvinylidene fluoride, polyacrylonitrile, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyphenyl ether, polyethylene ether ketone, polyphenylene sulfide, polyphenylene sulfone, polysulfone, polyether sulfone, polyarylate, polystyrene, Aromatic ring-containing polymers such as polyvinylphenol and derivatives of these polymers, cured resins such as phenolic resins and epoxy resins, and the like can be used. Among them, aromatic ring-containing polymers are preferable from the viewpoint of meshing with the electrode crystal lattice and interaction with adjacent layers.
  • Polymers used in the present invention are preferably aromatic ring-containing polymers having structures represented by the following general formulas (I) and (II).
  • polymers containing benzene rings are preferred.
  • the polymer containing the benzene ring is a non-conjugated polymer.
  • the non-conjugated polymer is a polymer containing benzene rings as side chains, such as polystyrene or polystyrene derivatives.
  • the aromatic ring-containing polymers having structures represented by the following general formulas (I) and (II) will be described in detail below.
  • A represents an aromatic ring
  • the aromatic ring includes an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Each of these may be a monocyclic ring or a condensed ring.
  • L represents a divalent linking group.
  • x and y represent an integer of 0 or 1 or more.
  • n represents the degree of polymerization and is 10 or more and 100,000 or less.
  • the aromatic ring represented by A includes an aromatic hydrocarbon ring and an aromatic heterocyclic ring, as described above. Each of these may be a monocyclic ring or a condensed ring. From the viewpoint of conductivity or insulation, the aromatic ring is preferably an aromatic hydrocarbon ring. From the viewpoint of solubility, the number of atoms constituting the aromatic ring of general formula (I) and general formula (II) excluding substituents is preferably 20 or less, more preferably 12 or less, and even more preferably 6 or less.
  • aromatic hydrocarbon rings examples include benzene ring, naphthalene ring, fluorene ring, anthracene ring, phenthrene ring, tetracene ring, pentacene ring, chrysene ring, pyrene ring, perylene ring, coronene ring, fluoranthene ring, dibenzoanthracene ring,
  • aromatic hydrocarbon rings include benzene ring, naphthalene ring, fluorene ring, anthracene ring, phenthrene ring, tetracene ring, pentacene ring, chrysene ring, pyrene ring, perylene ring, coronene ring, fluoranthene ring, dibenzoanthracene ring,
  • acene structures such as benzopyrene ring, preferably benzene ring and naphthalene
  • aromatic heterocyclic rings include pyridine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, acridine ring, thiophene ring, furan ring, pyrrole ring, benzofuran ring, benzothiophene ring, indole ring, imidazole ring and pyrazole ring.
  • oxazole ring isoxazole ring, thiazole ring, isothiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, dioxazole ring, dithiazole ring, tetrazole ring, pentazole ring and the like.
  • the aromatic ring represented by A is preferably a benzene ring, and specific examples include the structure of the following general formula (III).
  • X and Y represent hydrogen or a bond with the repeating unit L or A in the general formula (I) and general formula (II).
  • R 1 to R 5 represent hydrogen or substituents, each independently hydrogen atom, deuterium atom, halogen atom, hydroxy group, carboxy group, sulfo group, alkoxycarbonyl group, haloformyl group, formyl group, acyl group, alkoxy group, mercapto group, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, carbamoyl group, silyl group, phosphine oxide group, imide group, aromatic imide ring group, aromatic hydrocarbon ring group, It represents an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group, or a non-aromatic heterocyclic group, and may further have a substituent.
  • alkyl groups represented by R 1 to R 5 in general formula (I), general formula (II) and general formula (III) above include methyl group, ethyl group, propyl group, isopropyl group, (t ) butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group and the like.
  • Alkenyl groups represented by R 1 to R 5 include, for example, those having one or more double bonds in the above alkyl group, more specifically vinyl group, allyl group, 1-propenyl group, iso propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group and the like.
  • alkynyl groups represented by R 1 to R 5 include ethynyl group, acetylenyl group, 1-propynyl group, 2-propynyl group (propargyl group), 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-pentynyl group, 2-pentynyl group, 3-pentynyl group, 1-hexynyl group, 2-hexynyl group, 3-hexynyl group, 1-heptynyl group, 2-heptynyl group, 5-heptynyl group, 1-octynyl group, 3-octynyl group, 5-octynyl group and the like.
  • aromatic hydrocarbon ring groups (also referred to as aryl groups) represented by R 1 to R 5 include phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group and azulenyl. group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like.
  • aromatic heterocyclic groups represented by R 1 to R 5 include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group and triazolyl group (e.g., 1, 2, 4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group , benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced
  • non-aromatic hydrocarbon ring groups represented by R 1 to R 5 include cycloalkyl groups (eg, cyclopentyl group, cyclohexyl group, etc.), cycloalkoxy groups (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), cycloalkylthio monovalent groups derived from groups (eg, cyclopentylthio group, cyclohexylthio group, etc.), tetrahydronaphthalene ring, 9,10-dihydroanthracene ring, biphenylene ring, etc.;
  • cycloalkyl groups eg, cyclopentyl group, cyclohexyl group, etc.
  • cycloalkoxy groups eg, cyclopentyloxy group, cyclohexyloxy group, etc.
  • cycloalkylthio monovalent groups derived from groups eg, cyclopent
  • non-aromatic hydrocarbon ring groups represented by R 1 to R 5 include epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ⁇ -caprolactone ring, ⁇ -caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring,
  • alkoxy groups represented by R 1 to R 5 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, 2-ethylhexyloxy, octyloxy and nonyloxy. group, decyloxy group, undecyloxy group, dodecyloxy group, tridecyloxy group, tetradecyloxy group, pentadecyloxy group, hexadecyloxy group, heptadecyloxy group, octadecyloxy group and the like.
  • Acyl groups represented by R 1 to R 5 include, for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group and phenylcarbonyl group. group, naphthylcarbonyl group, pyridylcarbonyl group, and the like.
  • amino groups represented by R 1 to R 5 include amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group and naphthylamino group. , 2-pyridylamino group and the like.
  • Silyl groups represented by R 1 to R 5 include, for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group and phenyldiethylsilyl group.
  • Phosphine oxide groups represented by R 1 to R 5 include, for example, diphenylphosphine oxide group, ditolylphosphine oxide group, dimethylphosphine oxide group, dinaphthylphosphine oxide group, 9,10-dihydro-9-oxa-10- A phosphaphenanthrene-10-oxide group and the like can be mentioned.
  • Substituents that the groups represented by R 1 to R 5 may further have include, for example, each independently alkyl group (eg, methyl group, ethyl group, propyl group, isopropyl group, (t) butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group, etc.), cycloalkyl group (e.g., cyclopentyl group, cyclohexyl group, etc.), alkenyl group (e.g., vinyl group, allyl group, etc.) , an alkynyl group (e.g., propargyl group, etc.), an aromatic hydrocarbon group (also called an aryl group, such as a phenyl group, p-chlorophenyl group, mesityl group, tolyl group, x
  • oxazolyl group benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group , a benzothienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced with a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), halogen atoms (e.g., chlorine atom , bromine atom
  • aminocarbonyl group methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.
  • sulfinyl group e.g., methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group or arylsulfonyl group (e.g.
  • methylsulfonyl group ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.
  • amino groups e.g.
  • alkylsilyl group or arylsilyl group e.g., trimethylsilyl group, triethylsilyl group, (t) butyldimethyl silyl group, triisopropylsilyl group, (t) butyldiphenylsilyl group, triphenylsilyl group, trinaphthylsilyl group, 2-pyridylsilyl group, etc.
  • alkylphosphino group or arylphosphino group dimethylphosphino group, diethyl phosphino group, dicyclohexylphosphino group, methylphenylphosphino group, dipheny
  • L represents a divalent linking group, an alkylene group, an alkenylene group, a carbonyl group, an ether group, an imino group, an imide group, an amide group, an o-phenylene group. , m-phenylene group, p-phenylene group, sulfonyl group, sulfide group, thioester group, silyl group, phosphine oxide group, or divalent aromatic heterocyclic group, which may further have a substituent.
  • the alkylene group represented by L includes, for example, methylene group, ethylene group, trimethylene group, propylene group, butylene group, butane-1,2-diyl group, hexylene and the like.
  • the alkenylene group represented by L includes, for example, vinylene group, propenylene group, butenylene group, pentenylene group, 1-methylvinylene group, 1-methylpropenylene group, 2-methylpropenylene group, 1-methylpentenylene group, rene group, 3-methylpentenylene group, 1-ethylvinylene group, 1-ethylpropenylene group, 1-ethylbutenylene group, 3-ethylbutenylene group and the like.
  • Examples of the amide group represented by L include a methylcarbonylamino group, an ethylcarbonylamino group, a dimethylcarbonylamino group, a propylcarbonylamino group, a pentylcarbonylamino group, a cyclohexylcarbonylamino group, a 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group and the like.
  • divalent aromatic heterocyclic group represented by L includes , for example, aromatic Divalent groups derived from those mentioned as heterocyclic groups are included.
  • x and y represent 0 or an integer of 1 or more.
  • n represents the degree of polymerization and is 10 or more and 100,000 or less.
  • L and R 1 to R 5 may be the same or different.
  • devices using polymers represented by the following structural formulas (1) to (4) are described as comparative examples. This is because the absolute value of the difference between the common logarithms does not satisfy the numerical specification in the present invention. If the numerical specification is satisfied, it can be used in the present invention.
  • structural formula (5) is given as a comparative example to be described later.
  • n, x and y are integers
  • the degree of polymerization n is within the range of 10 to 100
  • the weight-average molecular weight of the polymer is preferably 1,000 or more from the viewpoint of suppressing the effects of crystallization and diffusion of low-molecular-weight components, and preferably has a molecular weight of 3,000,000 or less from the viewpoint of residual polymerization impurities. More preferably, it is 50,000 or more and 1,000,000 or less.
  • the weight average molecular weight here refers to the weight average molecular weight measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent and converted to polystyrene. If it cannot be measured with dimethylformamide, use tetrahydrofuran. If it cannot be measured, use hexafluoroisopropanol. If it cannot be measured with hexafluoroisopropanol, use 2-chloronaphthalene.
  • GPC gel permeation chromatography
  • the polymer content is preferably in the range of 5 to 80% by weight.
  • the polymer is sufficiently present at the interface on the electrode side, so that movement of chemical species such as charge carriers and compounds can be restricted between the light-emitting layer and the adjacent layer or between the light-emitting layer and the electrode.
  • the charge carrier balance can be maintained, and the generation of factors that cause deterioration and quenching of the organic EL element can be suppressed.
  • the mass ratio of the polymer is more preferably within the range of 15-65% by mass, and still more preferably within the range of 20-60% by mass.
  • the polymer is preferably a polymer containing a benzene ring selected from the above structural formulas (1) to (30) (however, (except Structural Formula (11)).
  • the polymer contains a benzene ring selected from the above structural formulas (1) to (30) in the side chain (however, (except Structural Formula (11)).
  • Luminescent dopant As for the light emission method of the organic EL device, there are two types of light emission methods, one is “phosphorescence emission” in which light is emitted when returning from the triplet excited state to the ground state, and the other is returning from the singlet excited state to the ground state. There are two kinds of “fluorescence emission” that emits light when the light is emitted.
  • triplet excitons are generated with a probability of 75% and singlet excitons are generated with a probability of 25%. It is an excellent method for achieving high efficiency and low power consumption.
  • a fluorescent dopant also referred to as a fluorescent dopant or a fluorescent compound
  • a phosphorescent dopant phosphorescent dopant, phosphorescent compound Also called.
  • the concentration of the emissive dopant in the emissive layer can be arbitrarily determined based on the particular dopant used and device requirements.
  • the concentration of the light-emitting dopant may be uniform in the layer thickness direction of the light-emitting layer, or may have an arbitrary concentration distribution.
  • the light-emitting layer may contain a plurality of types of light-emitting dopants.
  • dopants having different structures may be used in combination, or a fluorescent dopant and a phosphorescent dopant may be used in combination. This makes it possible to obtain an arbitrary emission color.
  • the doping method of the luminescent dopant of the present invention it may be mixed with the host in advance as an ink and applied to form a film, or a host layer may be formed and then a dopant solution is applied to the luminescent layer.
  • a method of penetrating to the interface on the anode side may be used.
  • the distribution state of the polymer, host compound, and luminescent dopant in the light-emitting layer is measured perpendicular to the substrate by dynamic secondary ion mass spectrometry, static secondary ion mass spectrometry, or argon cluster ion beam X-ray photoelectron spectroscopy. It can be known by analyzing the composition of the light-emitting layer in the (depth) direction. Specifically, by analyzing the presence or absence of metal elements specific to phosphorescent materials, specific mass fragments, or heteroelements in organic compounds, the distribution of compounds in the light-emitting layer can be observed on the order of nanometers. can be done.
  • the phosphorescent dopant is a compound in which emission from excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25°C), and has a phosphorescence quantum yield of 0 at 25°C. .01 or higher.
  • the phosphorescent dopant used in the light-emitting layer preferably has a phosphorescence quantum yield of 0.1 or more.
  • the phosphorescence quantum yield can be measured by the method described in Experimental Chemistry Course 7, 4th Edition, Spectroscopy II, page 398 (1992 edition, Maruzen). Phosphorescence quantum yield in solution can be measured using various solvents.
  • the phosphorescence-emitting dopant used in the light-emitting layer should achieve the phosphorescence quantum yield (0.01 or more) in any solvent.
  • the phosphorescent dopant can be appropriately selected from known materials used in the light-emitting layer of organic EL devices and used. Specific examples of known phosphorescent dopants that can be used in the present invention include the compounds described in the following documents.
  • preferred phosphorescent dopants include organometallic complexes having Ir as a central metal. Complexes containing at least one coordination mode of metal-carbon bond, metal-nitrogen bond, metal-oxygen bond, and metal-sulfur bond are more preferred.
  • the fluorescent dopant is a compound capable of emitting light from an excited singlet, and is not particularly limited as long as light emission from an excited singlet can be observed.
  • fluorescent dopants include anthracene derivatives, pyrene derivatives, chrysene derivatives, fluoranthene derivatives, perylene derivatives, fluorene derivatives, arylacetylene derivatives, styrylarylene derivatives, styrylamine derivatives, arylamine derivatives, boron complexes, coumarin derivatives, pyran derivatives, cyanine derivatives, croconium derivatives, squarium derivatives, oxobenzanthracene derivatives, fluorescein derivatives, rhodamine derivatives, pyrylium derivatives, perylene derivatives, polythiophene derivatives, rare earth complex compounds, and the like.
  • TTA delayed fluorescence compound
  • TTA Excited triplet-triplet annihilation
  • a luminescence method using delayed fluorescence has emerged to solve the problems of fluorescent compounds.
  • the TTA method originating from collisions between triplet excitons can be described by the following general formula. That is, conventionally, exciton energy is converted only to heat by non-radiative deactivation, but some of the triplet excitons have the advantage of being able to reverse intersystem crossover to singlet excitons that can contribute to light emission. In actual organic EL devices, it is possible to obtain an external extraction quantum efficiency approximately double that of conventional fluorescent light emitting devices.
  • T * +T * ⁇ S * +S (Wherein, T * represents a triplet exciton, S * represents a singlet exciton, and S represents a ground state molecule.)
  • T * represents a triplet exciton
  • S * represents a singlet exciton
  • S represents a ground state molecule.
  • the TADF method which is another high-efficiency fluorescence emission method, is a method that can solve the problems of TTA.
  • Fluorescent compounds have the advantage that they can be designed indefinitely as described above. That is, among molecularly designed compounds, there are compounds in which the energy level difference between the triplet excited state and the singlet excited state (hereinafter, appropriately abbreviated as " ⁇ EST ”) is extremely close. do.
  • examples of compounds that emit delayed fluorescence include International Publication No. 2011/156793, JP-A-2011-213643, and JP-A-2010. -93181, Japanese Patent No. 5366106, WO 2013/161437 and WO 2016/158540, etc., but the present invention is not limited thereto.
  • QD-OLED quantum dot-containing organic light-emitting device
  • QLED inorganic light emitting device
  • the contents described in JP-A-2015-156367 and JP-A-2018-078279 can be referred to.
  • the light-emitting layer according to the present invention may be a layer containing a perovskite compound.
  • perovskite compound means a compound having a perovskite structure.
  • the perovskite compound is preferably a perovskite compound in which an organic substance and an inorganic substance are constituent elements of the perovskite structure (a perovskite compound with an organic-inorganic hybrid structure).
  • the perovskite compound preferably has a structure represented by the following general formula (a) from the viewpoint of photoelectric conversion efficiency.
  • R represents an organic molecule.
  • M represents a metal atom.
  • X represents a halogen atom or a chalcogen atom.
  • R is an organic molecule, preferably a molecule represented by C1NmXn ( l , m and n all represent positive integers).
  • R is specifically methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, imidazole, azole, pyrrole, aziridine, azirine, azetidine, Azeto, imidazoline, carbazole and their ions (eg, methylammonium (CH 3 NH 3 ), etc.), phenethylammonium, and the like can be mentioned.
  • methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine and their ions and phenethylammonium are preferred, and methylamine, ethylamine, propylamine and their ions are more preferred.
  • M is a metal atom such as lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum and europium. mentioned. These elements may be used alone, or two or more of them may be used in combination.
  • X is a halogen atom or a chalcogen atom such as chlorine, bromine, iodine, sulfur, selenium and the like. These elements may be used alone, or two or more of them may be used in combination. Among them, a halogen atom is preferable because the perovskite compound becomes soluble in an organic solvent by containing a halogen atom in the structure, and application to an inexpensive printing method or the like becomes possible. Furthermore, iodine is more preferable because it narrows the energy bandgap of the organic-inorganic perovskite compound.
  • luminescent dopants examples include the following.
  • the host compound is a compound that is mainly responsible for charge injection and transport in the light-emitting layer, and its own light emission is substantially not observed in the organic EL device.
  • the organic EL device of the present invention is characterized in that a plurality of light-emitting pixels have a common electrode and a common host compound, wherein the host compound is composed of a plurality of types of host compounds, and the plurality of light-emitting pixels It is preferable that the composition ratios of the plurality of types of host compounds are equal in the pixel. By using a plurality of types of host compounds, it is possible to adjust the movement of electric charges, and it is possible to improve the efficiency of the organic EL device.
  • the host compound used in the light-emitting layer compounds conventionally used in organic EL devices can be used.
  • it may be a low-molecular compound, a polymer compound having repeating units, or a compound having a reactive group such as a vinyl group or an epoxy group.
  • the host compound preferably has a high glass transition temperature (Tg).
  • Tg glass transition temperature
  • the host compound preferably has a Tg of 80° C. or higher, more preferably 100° C. or higher.
  • the "glass transition point (Tg)" is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).
  • the host compound must be able to exist stably in all active species states of cation radical state, anion radical state, and excited state, and not undergo chemical changes such as decomposition and addition reactions. It is preferred that the host molecules do not migrate at the angstrom level in the layer during the passage of current.
  • the host compound that can be used in the present invention is not particularly limited, and compounds that are conventionally used in organic EL devices can be used.
  • Representative examples are those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, etc., or carboline derivatives and diazacarbazole derivatives (here and the diazacarbazole derivative means that at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.) and the like.
  • a known host compound that can be used in the present invention is preferably a compound that has hole-transporting ability and electron-transporting ability, prevents emission from becoming longer in wavelength, and has a high Tg as described above.
  • a conventionally known host compound may be used alone, or a plurality of types may be used in combination.
  • a plurality of types of host compounds it is possible to adjust the movement of electric charges, and to improve the efficiency of the organic EL device.
  • a plurality of conventionally known compounds it is possible to mix different luminescence, thereby obtaining an arbitrary luminescence color.
  • the host compound used in the present invention may be a low-molecular-weight compound, a high-molecular-weight compound having a repeating unit, or a low-molecular-weight compound (polymerizable host compound) having a polymerizable group such as a vinyl group or an epoxy group. Well, one or more of such compounds may be used.
  • the host compound of the present invention is preferably a host compound that dissolves in a non-halogen solvent, and more preferably an ester solvent. This is because the halogen solvent has the problem of dissolving the lower layer. Moreover, it is preferable that the molecular weight of the host compound is 1000 or less because it is easily dissolved.
  • the host compound used in the present invention is preferably a compound having a structure represented by the following general formula.
  • the light-emitting layer is preferably formed using a coating liquid containing a compound having a structure represented by the following general formula (1).
  • X represents O, S, or NR9.
  • R 9 is a hydrogen atom, deuterium atom, alkyl group, alkenyl group, alkynyl group, arylalkyl group, aromatic hydrocarbon ring group, aromatic heterocyclic group, non-aromatic hydrocarbon ring group, non-aromatic heterocyclic ring group or a substituent represented by the following general formula (2).
  • R 1 to R 8 each represent a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an amino group, a silyl group, a phosphine oxide group, and an aromatic hydrocarbon group. It represents a hydrogen ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group, a non-aromatic heterocyclic group, or a substituent represented by the following general formula (2). At least one of R 1 to R 9 represents a substituent represented by general formula (2) below. R 1 to R 9 may be the same or different, and may have a substituent. ]
  • each L represents an alkylene group, an alkenylene group, an o-phenylene group, an m-phenylene group, a p-phenylene group, an amide group or a divalent aromatic heterocyclic group, and further substituted You may have a group.
  • n represents an integer of 1 to 8; When n represents an integer of 2 or more, 2 or more L's may be the same or different.
  • R is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group or a non-aromatic represents a group hydrocarbon ring group, which may further have a substituent.
  • m represents an integer of 1 to 3;
  • At least one of L and R represents an alkylene group or an alkyl group.
  • R 1 to R 9 in general formula (1) have the same meanings as R 1 to R 6 in general formulas (I) to (III).
  • the linking group represented by L in the general formula (2) has the same definition as L in the general formulas (I) and (II).
  • the alkyl group having 1 to 20 carbon atoms represented by R includes, for example, those listed as the alkyl groups represented by R 1 to R 9 in the general formula (1). , groups having 1 to 20 carbon atoms.
  • Examples of the fluorinated alkyl group having 1 to 20 carbon atoms represented by R include groups in which hydrogen atoms of the above alkyl groups having 1 to 20 carbon atoms are substituted with fluorine atoms.
  • Examples of the alkoxy group having 1 to 20 carbon atoms represented by R include those having 1 to 20 carbon atoms among the alkoxy groups represented by R 1 to R 8 in the above general formula (1). group.
  • the aromatic hydrocarbon ring group, aromatic heterocyclic group or non-aromatic hydrocarbon ring group represented by R includes, for example, aromatic hydrocarbon rings represented by R 1 to R 9 in the general formula (1) groups, aromatic heterocyclic groups or non-aromatic hydrocarbon ring groups.
  • the substituents that L and R may further have include, for example, the same substituents that R 1 to R 9 may have in general formula (1). is mentioned.
  • At least one L is preferably an alkylene group having 1 to 6 carbon atoms.
  • at least one R is preferably an alkyl group having 1 to 6 carbon atoms.
  • Charge carrier transport layer (also referred to as “charge transport layer”) refers to a layer containing a compound having a function of transporting charge carriers, that is, electrons or holes. .
  • charge carrier transport layer (“charge transport layer”) is divided into an “electron transport layer” and a “hole transport layer” for explanation.
  • Electron transport layer is made of a material having a function of transporting electrons among charge carriers, and in a broad sense, an electron injection layer is also included in the electron transport layer.
  • the electron transport layer can be provided as a single layer or multiple layers.
  • the electron transport layer is preferably formed using a coating liquid containing an electron transport material described below.
  • the coating liquid preferably contains the polar fluorinated solvent.
  • the solubility in the polar fluorinated solvent is preferably lower in the order of the material of the electron transport layer, the material of the insulating layer, and the material of the light emitting layer.
  • the electron transporting material used for the electron transporting layer should have the function of transmitting electrons injected from the cathode to the light emitting layer.
  • the material thereof any one can be selected and used from conventionally known compounds. Examples thereof include metal complexes such as fluorene derivatives, carbazole derivatives, azacarbazole derivatives, oxadiazole derivatives, triazole derivatives, silole derivatives, pyridine derivatives, pyrimidine derivatives and 8-quinolinol derivatives.
  • metal-free or metal phthalocyanines or those whose terminals are substituted with alkyl groups, sulfonic acid groups, etc., can also be preferably used as electron transport materials.
  • carbazole derivatives azacarbazole derivatives, pyridine derivatives and the like are preferred in the present invention, and azacarbazole derivatives are more preferred.
  • the electron transport layer can be formed by thinning the electron transport material by a known method such as a spin coating method, a casting method, a printing method including an inkjet printing method, or an LB method. It can be formed by a wet process using a coating liquid containing an electron transporting material and a fluorinated alcohol solvent.
  • the layer thickness of the electron-transporting layer is not particularly limited, but is usually in the range of about 5 nm to 5 ⁇ m, preferably in the range of 5 to 200 nm.
  • the electron-transporting layer may have a single-layer structure composed of one or more of the above materials.
  • an electron transport layer having a high n property doped with an impurity as a guest material can also be used.
  • Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175 and J. Am. Appl. Phys. , 95, 5773 (2004).
  • the electron transport layer in the invention preferably contains an alkali metal salt of an organic substance.
  • an organic substance formate, acetate, propionic acid, butyrate, valerate, caproate, enanthate, caprylate, oxalate, malonate, and succinate , benzoate, phthalate, isophthalate, terephthalate, salicylate, pyruvate, lactate, malate, adipate, mesylate, tosylate, benzenesulfonate.
  • ком ⁇ онент preferably formate, acetate, propionate, butyrate, valerate, caproate, enanthate, caprylate, oxalate, malonate, succinate, benzoate, more preferably is preferably an alkali metal salt of an aliphatic carboxylic acid such as formate, acetate, propionate and butyrate, and preferably the aliphatic carboxylic acid has 4 or less carbon atoms. Acetate is most preferred.
  • the type of alkali metal in the organic alkali metal salt is not particularly limited, but includes Na, K, Cs and Li, preferably K and Cs, more preferably Cs.
  • the alkali metal salts of organic substances include combinations of the above organic substances and alkali metals, preferably Li formate, K formate, Na formate, Cs formate, Li acetate, K acetate, Na acetate, Cs acetate, Li propionate, Sodium propionate, K propionate, Cs propionate, Li oxalate, Na oxalate, K oxalate, Cs oxalate, Li malonate, Na malonate, K malonate, Cs malonate, Li succinate, succinic acid Na, K succinate, Cs succinate, Li benzoate, Na benzoate, K benzoate and Cs benzoate, more preferably Li acetate, K acetate, Na acetate and Cs acetate, most preferably Cs acetate
  • the content of these dopants is preferably in the range of 1.5 to 35% by mass, more preferably in the range of 3 to 25% by mass, and most preferably in the range of 5 to It is within the range of 15% by mass.
  • the hole-transport layer is composed of a hole-transport material having a function of transporting holes among charge carriers, and is broadly referred to as a hole-injection layer, an electron A blocking layer is also included in the hole transport layer. Also, the hole transport layer can be provided as a single layer or a plurality of layers.
  • the hole transport material has either hole injection or transport or electron blocking properties, and may be either organic or inorganic.
  • triazole derivatives for example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbenes. derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers, thiophene oligomers, and the like.
  • hole transport material those mentioned above can be used, and porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds can be used, and aromatic tertiary amine compounds can be used in particular. preferable.
  • aromatic tertiary amine compounds and styrylamine compounds include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl, N,N'-diphenyl-N,N'- Bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1 -bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl, 1,1-bis(4-di-p -tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-di
  • polymer materials in which these materials are introduced into the polymer chain or these materials are used as the main chain of the polymer can also be used.
  • Inorganic compounds such as p-type-Si and p-type-SiC can also be used as hole-injecting materials and hole-transporting materials.
  • Japanese Patent Application Laid-Open No. 11-251067, J. Am. Huang et. al. , Applied Physics Letters, 80 (2002), p. 139, so-called p-type hole transport materials can also be used. In the present invention, these materials are preferably used from the viewpoint of obtaining a light-emitting device with higher efficiency.
  • the hole-transporting layer is formed by applying the above-mentioned hole-transporting material by a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, a printing method including an inkjet printing method, and an LB method (Langmuir Blodgett method). can be formed by thinning.
  • the layer thickness of the hole-transporting layer is not particularly limited, but is usually in the range of about 5 nm to 5 ⁇ m, preferably in the range of 5 to 200 nm.
  • the hole transport layer may have a single-layer structure composed of one or more of the above materials.
  • the p-property can be increased by doping the material of the hole transport layer with impurities.
  • impurities examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175 and J. Am. Appl. Phys. , 95, 5773 (2004).
  • Electron blocking layer has the function of a hole transport layer in a broad sense.
  • the electron-blocking layer is made of a material that has the function of transporting holes but has a significantly low ability to transport electrons. By blocking electrons while transporting holes, the probability of recombination between electrons and holes is improved. can be made Moreover, the structure of a hole transport layer can be used as an electron blocking layer as needed.
  • the layer thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.
  • Charge carrier injection layer charge injection layer A “charge carrier injection layer (hereinafter also referred to as a “charge injection layer”)” is a compound having the function of injecting charge carriers, that is, electrons or holes. refers to a layer containing In the following description, the charge carrier injection layer (“charge injection layer”) is divided into “hole injection layer” and “hole injection layer”.
  • the charge injection layer is a layer for injecting charge carriers, that is, electrons or holes, provided between the electrode and the light emitting layer in order to reduce the driving voltage and improve the luminance of the emitted light.
  • charge carriers that is, electrons or holes
  • the details are described in "Organic EL element and its industrial front” (published by NTS on November 30, 1998), Part 2, Chapter 2, “Electrode materials” (pp. 123-166). , a hole-injection layer and an electron-injection layer.
  • An injection layer can be provided as needed.
  • a hole-injecting layer may be present between the anode and the light-emitting layer or the hole-transporting layer, and an electron-injecting layer may be present between the cathode and the light-emitting layer or the electron-transporting layer.
  • JP-A-9-45479 JP-A-9-260062, and JP-A-8-288069.
  • Examples include an oxide layer represented by vanadium oxide, an amorphous carbon layer, and a polymer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.
  • the electron injection layer Details of the electron injection layer are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, etc. Specifically, a metal layer represented by strontium, aluminum, etc. , an alkali metal halide layer typified by potassium fluoride, an alkaline earth metal compound layer typified by magnesium fluoride, an oxide layer typified by molybdenum oxide, and the like.
  • the electron injection layer is desirably a very thin film, and although it depends on the constituent materials, the layer thickness is preferably in the range of 1 nm to 10 ⁇ m.
  • an electrode material having a large work function (4 eV or more), an alloy, an electrically conductive compound, or a mixture thereof is preferably used.
  • electrode materials include metals such as Au, conductive transparent materials such as CuI, indium tin oxide (ITO), SnO 2 , ZnO and IZO.
  • a material such as IDIXO (In 2 O 3 —ZnO) that is amorphous and capable of forming a transparent conductive film may also be used.
  • the anode may be formed by forming a thin film of these electrode substances by a method such as vapor deposition or sputtering, and forming a pattern of a desired shape by photolithography. A pattern may be formed through a mask having a desired shape during vapor deposition or sputtering of the electrode material.
  • a wet film-forming method such as a printing method or a coating method may be used.
  • the transmittance is desirably greater than 10%, and the sheet resistance of the anode is preferably several hundred ⁇ / ⁇ or less.
  • the film thickness depends on the material, it is usually selected within the range of 10 to 1000 nm, preferably within the range of 10 to 200 nm.
  • Electroconductive compounds and mixtures thereof are used as electrode materials.
  • electrode materials include sodium, sodium-potassium alloys, magnesium, lithium, magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indium mixtures, aluminum/aluminum oxide (Al 2 O 3 ) mixtures, silver, indium, lithium/aluminum mixtures and rare earth metals;
  • a mixture of an electron injection metal and a second metal that has a higher work function and is more stable such as a magnesium/silver mixture, magnesium /aluminum mixtures, magnesium/indium mixtures, aluminum/aluminum oxide ( Al2O3 ) mixtures, lithium/aluminum mixtures, silver and aluminum, etc. are suitable.
  • the cathode can be produced by forming a thin film of these electrode substances by a method such as vapor deposition, sputtering, or lamination.
  • the sheet resistance of the cathode is preferably several hundred ⁇ / ⁇ or less, and the film thickness is usually selected within the range of 10 nm to 5 ⁇ m, preferably within the range of 50 to 200 nm.
  • the anode or the cathode of the organic EL element is transparent or semi-transparent because the luminance of the emitted light is improved.
  • a transparent or translucent cathode can be produced by forming the above-mentioned metal on the cathode with a film thickness in the range of 1 to 20 nm and then forming thereon the conductive transparent material mentioned in the explanation of the anode. By applying this, it is possible to fabricate a device in which both the anode and the cathode are transparent.
  • Non-luminous image display part The organic EL element of the present invention has an image display part composed of a "luminous image display part” and a “non-luminous image display part”. , a portion other than the “luminescent image display portion” that constitutes the image display portion. That is, the organic EL element of the present invention has a form in which a luminescence image display portion in which luminescence pixels are arranged in dots is provided between a plurality of non-luminescence image display portions included in the image display portion. is preferred.
  • partition walls functioning as an electrically insulating layer and ink containing a light-emitting material are permeated. It is preferable that the non-insulating ink-receiving layer portion functions as a partition wall (insulating layer).
  • insulating refers to a property in which electrons and holes are difficult to move, that is, it is difficult to conduct electricity. say nature. In other words, it refers to the property that the electrical conductivity is less than 10 ⁇ 5 S/m.
  • electric resistivity a value obtained under conditions conforming to JIS-K-6911 by a constant voltage application/leakage current measurement method using a double ring electrode is used.
  • a bank may be formed in advance, or after forming an insulating layer uniformly, a light-emitting layer is formed by ink-jetting separately, and spontaneously Banks may be formed, but the former method is preferred.
  • the organic EL device of the present invention it is a preferred form to form a bank as an insulating layer on the substrate surface.
  • the bank is formed on the periphery of the area to be coated with the liquid containing the material constituting the organic EL element on the substrate surface, and the applied liquid containing the material constituting the organic EL element is applied. It has the role of preventing outflow to the outside of the attached area and the role of providing electrical insulation.
  • FIG. 3 is a cross-sectional view showing an example of a substrate having banks.
  • the regions of the surface of the substrate 1 delimited by the banks 2 are bank depressions 2a, and the bank surfaces are bank projections 2b.
  • a light-emitting image display portion according to the present invention is formed in the concave portion 2a.
  • the height of the bank is not particularly limited as long as it is possible to prevent the applied ink from flowing out, but it is preferably in the range of 1.1 to 2.5 ⁇ m. A more preferable range is 1.5 to 2.5 ⁇ m.
  • Insulating Material A known material can be used as the material of the insulating layer (bank) according to the present invention, but the polysiloxane skeleton has at least one organic group other than an alkyl group. It is preferable to contain an organic-inorganic hybrid polymer. By having at least one organic group other than an alkyl group in the polysiloxane structure, it is possible to obtain a light-emitting image display portion having excellent solvent resistance and peeling resistance.
  • organic-inorganic hybrid polymer structure As the organic group other than the alkyl group of the organic-inorganic hybrid polymer used in the present invention, known substituents can be used without particular limitation. group, nitro group, nitroso group, azo group, diazo group, azide group, carbonyl group, phenyl group, hydroxy group, peroxy group, acyl group, acetyl group, aldehyde group, carboxy group, amide group, imide group, ester group, Oxime groups, thiol groups, sulfo groups, urea groups, isonitrile groups, allene groups, acryloyl groups, methacryloyl groups, epoxy groups, oxetane groups, isocyanate groups, and the like can be used. Among the above, an acryloyl group, an epoxy group, or an isocyanate group is preferred. Among them, an acryloyl group is particularly preferred.
  • polysiloxane structure examples include polysiloxanes (including polysilsesquioxanes) having Si—O—Si bonds.
  • polysiloxane can include [R 3 SiO 1/2 ], [R 2 SiO], [RSiO 3/2 ] and [SiO 2 ] as general structural units.
  • R is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (eg, methyl group (Me), ethyl group, propyl group, etc.), an aryl group (eg, phenyl group (Ph), etc.), unsaturated alkyl group ( are independently selected from the group consisting of, for example, vinyl groups, etc.).
  • Examples of specific polysiloxane structures include [PhSiO 3/2 ], [MeSiO 3/2 ], [HSiO 3/2 ], [MePhSiO], [Ph 2 SiO], [PhViSiO], [ViSiO 3/2 ] (Vi represents a vinyl group), [MeHSiO], [MeViSiO], [Me 2 SiO] and [Me 3 SiO 1/2 ]. Mixtures and copolymers of polysiloxanes can also be used.
  • binder resin in addition to the organic-inorganic hybrid polymer used in the present invention, a binder resin may be used in the insulating layer within a range that does not impair the effects of the present invention.
  • binder resins include cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate; Polyvinyl alcohol derivatives such as polyester, polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polyvinyl benzal, norbornene-based polymers containing norbornene compounds, polymethyl methacrylate, polyethyl methacrylate, polypropyltyl methacrylate, polybutyl methacrylate, polymethyl Acrylic resins such as acrylates or copolymers of acrylic resins and other resins can be used, but the material is not particularly limited to these exemplified resin materials. Among these binder resins
  • insulating metal oxide As a material for the insulating layer, it is also preferable to contain an insulating metal oxide in the binder resin.
  • the insulating metal oxide is not particularly limited, alumina, zirconia, titania, silica, magnesia, or niobium is preferable from the viewpoint of chemical stability and physical stability.
  • metal oxides having a dielectric constant of 100 or more are preferable, and examples thereof include rutile-type titanium oxide (TiO 2 ), zirconium oxide (ZrO), niobium pentoxide (Nb 2 O 3 ), and titanic acid.
  • TiO 2 titanium oxide
  • ZrO zirconium oxide
  • Nb 2 O 3 niobium pentoxide
  • titanic acid barium (BaTiO 3 ), strontium titanate (SrTiO 3 ), lead titanate (PbTiO 3 ), barium zirconate titanate (BaTi 0.5 Zr 0.5 O 3 ), lead zirconate titanate (PbTi 0.5 ) . 5 Zr 0.5 O 3 ) or the like , or water thereof hydrates, and insulating solid solutions containing at least one of these in the composition.
  • the insulating layer may be patterned in advance on the non-image portion, or a method of forming a current flow path (conductive path) by injecting ink containing a soluble functional material into the insulating layer is used.
  • a method of forming a current flow path (conductive path) by injecting ink containing a soluble functional material into the insulating layer is used.
  • the insulating layer is formed by the following method.
  • a 0.5 mm glass substrate (Eagle XG manufactured by Corning) was washed with an alkali, and then a photosensitive polyimide containing 30% by mass of titanium oxide (manufactured by Merck) was applied by spin coating, and the temperature was kept at 60°C. is pre-baked for 120 seconds.
  • pattern exposure is performed by a photo process, development is performed with tetramethylammonium hydroxide (abbreviation: TMAH), and rinsing is performed with pure water to form banks having openings.
  • TMAH tetramethylammonium hydroxide
  • Polar fluorinated solvent A polar fluorinated solvent is preferably used for forming the insulating layer. A polar fluorinated solvent is also preferably used for forming an electron transport layer, which will be described later.
  • the polar fluorinated solvent refers to a solvent that contains fluorine atoms in the solvent molecule, has a dielectric constant of 3 or more, and has a solubility in water of 5 g/L or more at 25°C.
  • the boiling point of the polar fluorinated solvent is preferably within the range of 50 to 200°C.
  • the temperature is set to 50° C. or higher, it is possible to more reliably suppress the occurrence of unevenness due to heat of evaporation during drying of the coating film.
  • the temperature is set to 200° C. or less, the solvent can be dried quickly, the solvent content in the formed layer is reduced, so that the crystal growth in the layer can be suppressed more reliably, and the solvent escape route is rough. Therefore, the density is improved and the current efficiency can be increased. More preferably, it is within the range of 70 to 150°C.
  • the water content of the polar fluorinated solvent is preferably as low as possible because even a very small amount of water is a quencher of light emission, preferably 100 ppm or less, more preferably 20 ppm or less.
  • the content of impurities other than water in the polar fluorinated solvent is as low as 100 ppm, because even a very small amount can become a quencher of light emission, cause air bubbles, or cause deterioration of the film quality after drying.
  • the following is preferable, and 20 ppm or less is more preferable.
  • Impurities other than water include oxygen, inert gases such as nitrogen, argon and carbon dioxide, and inorganic compounds or metals brought in from catalysts, adsorbents and equipment used during preparation and purification.
  • Examples of the polar fluorinated solvent include fluorinated alcohols, fluorinated acrylates, fluorinated methacrylates, fluorinated esters, fluorinated ethers, fluorinated hydroxyalkylbenzenes, and fluorinated amines, and fluorinated alcohols, fluorinated esters, and fluorinated ethers. is more preferred, and fluorinated alcohol is even more preferred from the viewpoint of solubility and drying property.
  • the number of carbon atoms in the fluorinated alcohol is preferably 3 to 5 from the viewpoint of the boiling point and the solubility of the material.
  • the fluorine-substituted position is, for example, the position of hydrogen in the case of alcohol, and the fluorination rate is sufficient as long as it does not impair the solubility of the layer material, and is fluorinated to the extent that the lower layer material is not eluted. is desirable.
  • fluorinated alcohols examples include 1H,1H-pentafluoropropanol, 6-(perfluoroethyl)hexanol, 1H,1H-heptafluorobutanol, 2-(perfluorobutyl)ethanol (FBEO), 3-(perfluorobutyl ) propanol, 6-(perfluorobutyl) hexanol, 2-perfluoropropoxy-2,3,3,3-tetrafluoropropanol, 2-(perfluorohexyl) ethanol, 3-(perfluorohexyl) propanol, 6- (perfluorohexyl)hexanol, 1H,1H-(perfluorohexyl)hexanol, 6-(perfluoro-1-methylethyl)hexanol, 1H,1H,3H-tetrafluoropropanol (TFPO), 1H,1H,5H- o
  • fluorinated ethers examples include hexafluorodimethyl ether, perfluorodimethoxymethane, perfluorooxetane, perfluoro-1,3-dioxolane, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoro Propyl ether etc. are mentioned.
  • fluorinated esters examples include methyl perfluorobutyrate, ethyl perfluorobutyrate, methyl perfluoropropionate, methyl difluoroacetate, ethyl difluoroacetate, methyl-2-trifluoromethyl-3,3,3- and trifluoropropionate.
  • the content of the insulating compound is preferably within the range of 0.05 to 10% by mass, and the content of the polar fluorinated solvent is preferably within the range of 90 to 99.95% by mass in the coating liquid for forming the insulating layer.
  • the polar fluorinated solvent may be a mixed solvent of two or more polar fluorinated solvents, or a mixture of a polar fluorinated solvent and a solvent other than a polar fluorinated solvent, as long as it does not dissolve the light-emitting layer material.
  • a solvent may be used.
  • a mixed solvent of fluorinated alcohol and alcohol can be used.
  • the content of the polar fluorinated solvent is preferably 50% by mass or more.
  • Substrate The material of the substrate used in the organic EL device is not particularly limited, and preferable examples include glass, quartz, and resin films. Particularly preferred is a resin film that imparts flexibility to the organic EL element and can be embedded in a printed matter or the like.
  • resin films include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate (CAP ), cellulose esters such as cellulose acetate phthalate and cellulose nitrate, or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, Polyethersulfone (PES), polyphenylene sulfide, polysulfones, polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylates, Arton (trade name, manufactured by JSR Corporation) or APEL (trade name, manufactured by Mitsu
  • a gas barrier film may be formed on the surface of the resin film by a coating of an inorganic substance, an organic substance, or a hybrid coating of both.
  • the gas barrier film has a water vapor permeability (25 ⁇ 0.5°C, humidity (90 ⁇ 2)% RH) measured by a method conforming to JIS K 7129-1992 of 0.01 g/(m 2 24 h) or less. is preferably a gas barrier film.
  • the oxygen permeability measured by a method based on JIS K 7126-1987 is 1 ⁇ 10 -3 mL / (m 2 ⁇ 24 h ⁇ atm) or less, and the water vapor permeability is 1 ⁇ 10 -5 g / It is preferably a high gas barrier film of (m 2 ⁇ 24 h) or less.
  • any material can be used as long as it has a function of suppressing penetration of moisture, oxygen, and the like.
  • silicon oxide, silicon dioxide and silicon nitride can be used.
  • the order of lamination of the inorganic layer and the organic layer is not particularly limited, but it is preferable to alternately laminate the two layers a plurality of times.
  • the method for forming the gas barrier film is not particularly limited, and examples include vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, and atmospheric pressure plasma polymerization.
  • a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used.
  • atmospheric pressure plasma polymerization as described in JP-A-2004-68143 is preferred.
  • sealing means used for sealing the organic EL device of the present invention for example, a method of adhering a sealing member, an electrode, and a supporting substrate with an adhesive can be mentioned. .
  • the sealing member may be arranged so as to cover the display area of the organic EL element, and may be in the form of a concave plate or a flat plate. Moreover, transparency and electric insulation are not particularly limited.
  • glass plates glass plates, polymer plates/films, metal plates/films, and the like can be mentioned.
  • glass plates include soda-lime glass, barium-strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass and quartz.
  • polymer plate polycarbonate, acryl, polyethylene terephthalate, polyether sulfide, polysulfone, and the like can be used.
  • Metal plates include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium and tantalum.
  • a polymer film and a metal film can be preferably used because the organic EL element can be made thinner.
  • the polymer film preferably has an oxygen permeability of 10 ⁇ 3 g/(m 2 ⁇ 24 h) or less and a water vapor permeability of 10 ⁇ 3 g/(m 2 ⁇ 24 h) or less. Further, it is more preferable that both the water vapor permeability and the oxygen permeability are 10 ⁇ 5 g/(m 2 ⁇ 24 h) or less.
  • Sandblasting, chemical etching, or the like is used to process the sealing member into a concave shape.
  • adhesives include photocurable and thermosetting adhesives having reactive vinyl groups of acrylic acid-based oligomers and methacrylic acid-based oligomers, and moisture-curable adhesives such as 2-cyanoacrylic acid esters. be able to.
  • Thermal and chemical curing types such as epoxy systems can also be mentioned. Mention may also be made of hot-melt polyamides, polyesters and polyolefins. Further, a cationic curing type ultraviolet curing type epoxy resin adhesive can be mentioned.
  • a desiccant may be dispersed in the adhesive.
  • a commercially available dispenser may be used to apply the adhesive to the sealing portion, or printing such as screen printing may be used.
  • the electrode and the organic functional layer may be coated on the outside of the electrode on the side facing the supporting substrate with the organic functional layer interposed therebetween, and inorganic and organic layers may be formed in contact with the supporting substrate to form a sealing film.
  • the material for forming the film may be any material that has a function of suppressing the infiltration of substances that cause deterioration of the device, such as moisture and oxygen.
  • silicon oxide, silicon dioxide, silicon nitride, and the like can be used.
  • the method for forming these films is not particularly limited. A method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used.
  • An inert gas such as nitrogen or argon, or an inert liquid such as fluorocarbon or silicone oil may be injected into the gap between the sealing member and the display area of the organic EL element in the gas phase and the liquid phase.
  • a vacuum is also possible.
  • a hygroscopic compound can be sealed inside.
  • hygroscopic compounds include metal oxides (e.g. sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (e.g. sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate, etc.), Metal halides (e.g. calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide barium iodide, magnesium iodide, etc.) and perchlorates (e.g. barium perchlorate, magnesium perchlorate etc.), etc., and anhydrous salts are preferably used for sulfates, metal halides and perchlorates.
  • metal oxides e.g. sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.
  • sulfates e.g. sodium sulfate, calcium sulfate, magnesium s
  • a protective film or a protective plate may be provided on the outside of the sealing film or film for sealing on the side facing the support substrate with the organic functional layer interposed therebetween in order to increase the mechanical strength of the element.
  • the mechanical strength thereof is not necessarily high, so it is preferable to provide such a protective film or protective plate.
  • the same glass plate, polymer plate/film, metal plate/film, etc. used for the above sealing can be used. It is preferred to use polymer films.
  • the organic EL element emits light inside a layer with a higher refractive index than air (within a refractive index range of about 1.6 to 2.1). It is generally said that only light within the range of about 15 to 20% of the light can be extracted.
  • Methods for improving the efficiency of extracting light include, for example, forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (see, for example, US Pat. No. 4,774,435); A method of improving efficiency by imparting properties (for example, JP-A-63-314795), a method of forming a reflective surface on the side surface of an element (for example, JP-A-1-220394), a substrate and a light emitter A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between them (for example, JP-A-62-172691), a flat layer having a lower refractive index than the substrate between the substrate and the light emitter (for example, Japanese Patent Application Laid-Open No.
  • these methods can be used in combination with the organic EL device.
  • a method of forming a diffraction grating between the substrate and the outside world, including between or between any of the substrate and the light-emitting layer, can be preferably used.
  • the present invention can obtain an element with even higher luminance or excellent durability.
  • the low refractive index layer examples include airgel, porous silica, magnesium fluoride, and fluoropolymers. Since the refractive index of the transparent substrate is generally in the range of about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Moreover, it is preferable that it is 1.35 or less.
  • the thickness of the low refractive index medium is at least twice the wavelength in the medium. This is because when the thickness of the low-refractive-index medium is about the wavelength of light and reaches a thickness at which the electromagnetic wave seeped out by evanescence penetrates into the substrate, the effect of the low-refractive-index layer is weakened.
  • the method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving the light extraction efficiency.
  • This method utilizes the property that a diffraction grating can change the direction of light to a specific direction different from refraction by first-order diffraction, second-order diffraction, or so-called Bragg diffraction.
  • light that cannot go out due to total reflection between layers or the like is diffracted by introducing a diffraction grating in one of the layers or in the medium (inside the transparent substrate or in the transparent electrode), It's about getting the light out.
  • the diffraction grating to be introduced preferably has a two-dimensional periodic refractive index. This is because the light emitted from the light-emitting layer is randomly generated in all directions, so a general one-dimensional diffraction grating that has a periodic refractive index distribution in only one direction can only diffract light traveling in a specific direction. Therefore, the light extraction efficiency does not increase so much.
  • the position where the diffraction grating is introduced may be between any of the layers or in the medium (inside the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light-emitting layer where light is generated.
  • the period of the diffraction grating is preferably in the range of about 1/2 to 3 times the wavelength of light in the medium.
  • the arrangement of the diffraction gratings is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.
  • the organic EL element of the present invention is processed so as to provide a structure on the light extraction side of the support substrate (substrate), for example, a microlens array, or a so-called light condensing sheet.
  • the luminance in a specific direction can be increased by condensing light in a specific direction, for example, in the front direction with respect to the light emitting surface of the element.
  • square pyramids each having a side of 30 ⁇ m and an apex angle of 90° are arranged two-dimensionally on the light extraction side of the support substrate.
  • One side is preferably within the range of 10 to 100 ⁇ m. If it is smaller than this, the effect of diffraction will occur and coloring will occur.
  • the condensing sheet it is possible to use, for example, a material that has been put to practical use in the LED backlight of the liquid crystal display device.
  • a brightness enhancement film (BEF) manufactured by Sumitomo 3M Co., Ltd. can be used as such a sheet.
  • the shape of the prism sheet may be, for example, a substrate on which delta-shaped stripes with an apex angle of 90° and a pitch of 50 ⁇ m are formed. A shape or other shape may be used.
  • a light diffusing plate/film may be used together with the condensing sheet in order to control the light emission angle from the organic EL element.
  • a diffusion film (light up) manufactured by Kimoto Co., Ltd. can be used.
  • tandem-type organic EL element for example, US Pat. No. 6,337,492, US Pat. 6107734, US Patent No. 6337492, JP 2006-228712, JP 2006-24791, JP 2006-49393, JP 2006-49394, JP 2006-49396 JP, JP 2011-96679, JP 2005-340187, JP 4711424, JP 3496681, JP 3884564, JP 4213169, JP 2010-192719 , JP 2009-076929, JP 2008-078414, JP 2007-059848, JP 2003-272860, JP 2003-045676, International Publication No. 2005/009087 and International
  • the device configuration, constituent materials, and the like described in Japanese Unexamined Patent Publication No. 2005/094130 and the like can be mentioned, the present invention is not limited thereto.
  • the anode 12 is formed on the substrate 11 .
  • the insulating layer 2 is formed on the anode 12, and the hole injection layer 13 and the hole transport layer 14 are formed in this order in the concave portions of the insulating layer 2.
  • the light-emitting layer 15 is formed using the light-emitting layer forming coating solution.
  • an electron transport layer 16 is formed on the light emitting layer 15 using a coating solution for forming an electron transport layer.
  • an electron injection layer 17 and a cathode 18 are formed on the electron transport layer 16 .
  • Anode 12 and cathode 18 form a common electrode for the light emitting layer.
  • the light-emitting pixels include four colors (B, G, R, and W (white)), five colors (B, G, R, W (white), and LB).
  • (Mixed color of B and G) and O (Mixed color of G and R) are also preferable, and one or more types of configurations suitable for the image area can be selected from these emission colors.
  • each layer other than the light-emitting layer that constitutes the organic EL element 10 any method such as a wet method, vapor deposition, or sputtering may be used as described above. Also, the formation of the light-emitting layer and the electron transport layer is not limited to the wet method, and a method such as vapor deposition or sputtering may be used. However, from the viewpoint of cost, it is preferable to use a wet method for any of the layers constituting the organic EL element 10 .
  • the device after forming the cathode 18 is sealed (not shown).
  • the sealing means used for sealing the element known members and methods can be used.
  • any method such as a wet method, vapor deposition, and sputtering may be used as described above.
  • a wet method and particularly preferably to use an inkjet printing method, because deterioration in performance during manufacturing in the air is suppressed and costs are suppressed.
  • liquid media used in inkjet printing examples include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, isopropyl acetate, propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate, and halogenated carbons such as dichlorobenzene.
  • ketones such as methyl ethyl ketone and cyclohexanone
  • fatty acid esters such as ethyl acetate, isopropyl acetate, propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate
  • halogenated carbons such as dichlorobenzene.
  • a solvent having a boiling point within the range of 50 to 180° C. is preferably used.
  • a dispersion method it can be dispersed by a dispersion method such as ultrasonic wave, high shear force dispersion, media dispersion, or the like.
  • the solvent content contained in the organic EL element is within the range of 0.01 to 1 ⁇ g/cm 2 .
  • concentration 0.01 ⁇ g/cm 2 or less
  • the organic film becomes sparse, which causes a high voltage when the device is driven. resulting in low efficiency and a short drive life.
  • solvent contents can be determined by thermal desorption spectroscopy.
  • the luminescent layer according to the present invention is preferably formed by an inkjet printing method, particularly preferably by an inkjet printing method in the atmosphere.
  • an inkjet printing method particularly preferably by an inkjet printing method in the atmosphere.
  • the effect of the active gas in the film forming atmosphere is more pronounced than in the case of forming a film by vapor deposition or spin coating, resulting in a decrease in luminous efficiency and a short life.
  • the method of forming other layers constituting the organic EL element is not limited, and may be an inkjet printing method or other methods.
  • the inkjet head used in the inkjet printing method may be of an on-demand system or a continuous system.
  • an electro-mechanical conversion method eg, single cavity type, double cavity type, bender type, piston type, share mode type, shared wall type, etc.
  • an electro-thermal conversion method eg, thermal ink jet type
  • an electrostatic attraction method e.g., electric field control type, slit jet type, etc.
  • a discharge method e.g., spark jet type, etc.
  • a serial head method, a line head method, or the like can be used without limitation.
  • the volume of ink droplets ejected from the head is preferably in the range of 0.5 to 100 pL. It is more preferably in the range of 2 to 50 pL from the viewpoint of reducing coating unevenness and increasing the printing speed. Note that the volume of the ink droplet can be appropriately adjusted by adjusting the applied voltage or the like.
  • the print resolution is preferably within the range of 180 to 10,000 dpi (dots per inch), more preferably within the range of 360 to 2,880 dpi, and can be appropriately set in consideration of wet thickness, volume of ink droplets, and the like.
  • the wet thickness of the wet coating film at the time of inkjet coating can be appropriately set, preferably within the range of 1 to 100 ⁇ m, more preferably within the range of 1 to 30 ⁇ m, most preferably within the range of 1 to 30 ⁇ m. is within the range of 1 to 5 ⁇ m, the effect of the present invention is exhibited more remarkably.
  • the wet thickness can be calculated from the coating area, print resolution, and ink droplet volume.
  • Inkjet printing methods include a one-pass printing method and a multi-pass printing method.
  • the one-pass printing method is a method of printing a predetermined print area by one head scan.
  • the multi-pass printing method is a method of printing a predetermined print area by multiple head scans.
  • a wide head in which nozzles are arranged over a width equal to or greater than the width of the desired coating pattern.
  • a wide head that is at least as wide as the width of each coating pattern may be used.
  • FIG. 2 shows a conceptual diagram showing that the luminescent pixels 21 to 23 are arranged in dots when viewed from the direction perpendicular to the surface of the organic EL element 10 .
  • the position of each dot may be in a regular permutation or in a staggered arrangement. Among them, a staggered arrangement is more preferable.
  • FIG. 4A, 4B, and 4C are schematic diagrams showing an example of a single-pass system (line head system) inkjet recording apparatus applicable to the method for manufacturing an organic EL element of the present invention.
  • 100 is a line head type head unit that ejects inks of different hues (for example, inks containing compounds that emit red (R), green (G), and blue (B) colors). It is preferably composed of heads 102 to 104 and the nozzle pitch of each head is about 360 dpi.
  • the dpi referred to in the present invention represents the number of dots per 2.54 cm.
  • the substrates 1 are fed out in the direction of the arrow from the transport mechanism 101 in a state of being stacked in a roll.
  • FIG. 4B is a bottom view showing the arrangement of nozzles at the bottom of each head. As shown in FIG. 4B, the nozzles N of the head 102, the head 103, and the head 104 are staggered by half a pitch. With such a head structure, a more dense image can be formed.
  • FIG. 4C is a schematic diagram showing an example of a head unit configuration.
  • a head unit HU in which a plurality of heads H are arranged in a zigzag arrangement so as to cover the entire width of the substrate.
  • a coating liquid (ink) containing a luminescent dopant, a host compound, or the like that forms the luminescent layer of the organic EL element and a solvent is applied onto the substrate while the substrate is continuously conveyed, or
  • a coating liquid (ink) containing an organic functional material for forming an organic functional layer and a solvent is sequentially ejected as ink droplets onto a substrate to form a light-emitting layer and an organic functional layer.
  • An inkjet head having a configuration described in publications and the like can be appropriately selected and applied.
  • the organic EL element of the above-described embodiment is a surface or minute light emitter, it can be used as various light sources.
  • Lighting device For example, lighting devices such as home lighting and in-vehicle lighting, backlights for clocks and liquid crystals, lighting for billboard advertisements, light sources for traffic lights, light sources for optical storage media, light sources for electrophotographic copiers, light sources Light sources for communication processors, light sources for optical sensors, and the like.
  • the organic EL element of the present invention is a simple display device, it is possible to finely produce according to on-demand by a two-dimensional inkjet method or a three-dimensional inkjet method. It is possible to provide the original model and the like.
  • element No. 1 produced under an inert gas.
  • A element No. produced in the atmosphere.
  • B device No. manufactured for hole mobility measurement.
  • H element No. manufactured for electron mobility measurement. is marked with an E.
  • Mw is the weight average molecular weight of each commercial product
  • Mn is the number average molecular weight
  • Mv is the viscosity average molecular weight.
  • Polyethylene [Mw: ⁇ 4k, manufactured by Sigma-Aldrich] (3) Polychlorotrifluoroethylene [manufactured by Daikin Industries, Ltd., Polyflon (registered trademark) M-12]
  • Polyvinylidene fluoride [Mw: 410 to 575, manufactured by Piezotech, Piezotech (registered trademark) RT-TS]
  • Poly(3,4-ethylenedioxythiophene) [manufactured by Sigma-Aldrich, Aedtron C-NM] (6) Poly(2-vinylpyridine) [Mn: 152k, Mw: 159k, manufactured by Sigma-Aldrich]
  • Example 1 ⁇ Production of organic EL element under inert gas> ⁇ Production of Organic EL Element A (100 A)>> A bottom emission type organic EL element 100A was manufactured by laminating and sealing an anode/light-emitting layer/cathode on a substrate as follows.
  • an atmospheric pressure plasma discharge treatment apparatus having the configuration described in Japanese Patent Application Laid-Open No. 2004-68143 was used on the entire surface of a polyethylene naphthalate film (manufactured by Teijin DuPont, hereinafter abbreviated as PEN) on the anode forming side.
  • PEN polyethylene naphthalate film
  • an inorganic gas barrier layer made of silicon oxide (SiOx; 1 ⁇ x ⁇ 4) was formed to a layer thickness of 500 nm.
  • SiOx silicon oxide
  • ITO indium tin oxide
  • the coating solution was applied to the anode prepared above using a Konica Minolta inkjet head (MEMS head 1 pL) so as to form a square coating pattern of 100 ⁇ m on a side at four locations with an interval of 10 ⁇ m.
  • MEMS head 1 pL Konica Minolta inkjet head
  • Triethylene glycol monobutyl ether was used as the coating liquid.
  • the substrate coated with the coating liquid was subjected to a lyophilic treatment.
  • Argon gas was used as the discharge gas
  • oxygen gas was used as the reactive gas.
  • the power source used for plasma generation was PHF2-K manufactured by Heiden Laboratory, and a voltage of about 2 kV was applied to generate plasma.
  • the coating liquid was removed by cleaning the lyophilic substrate surface using a dry ice cleaner manufactured by Air Water. As a result, a substrate on which a pattern of lyophilic regions and lyophobic regions was formed was obtained.
  • the substrate on which the anode and bank were formed was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.
  • a piezoelectric inkjet printer head manufactured by Konica Minolta which is a piezoelectric inkjet printer head having the structure shown in FIG. KM1024i" was injected onto a substrate at 40° C. under the condition that the layer thickness after drying was 50 nm, and then dried at 120° C. for 30 minutes to form a light-emitting layer.
  • the substrate was attached to the vacuum deposition apparatus.
  • a molybdenum resistance heating boat containing sodium fluoride and potassium fluoride was attached to a vacuum deposition apparatus, and the vacuum chamber was evacuated to 4 ⁇ 10 ⁇ 5 Pa. After that, the boat was energized and heated, and sodium fluoride was vapor-deposited on the light-emitting layer and bank at 0.02 nm/sec to form a thin film with a thickness of 1 nm. Similarly, potassium fluoride was vapor-deposited on the sodium fluoride thin film at 0.02 nm/sec to form an electron injection layer with a layer thickness of 1.5 nm.
  • sealing substrate was adhered to the laminate formed by the above steps using a commercially available roll laminator.
  • a 1.5 ⁇ m-thick adhesive was applied to a flexible 30 ⁇ m-thick aluminum foil (manufactured by Toyo Aluminum Co., Ltd.) using a two-liquid reactive urethane-based adhesive for dry lamination.
  • a layer was provided and a polyethylene terephthalate (PET) film having a thickness of 12 ⁇ m was laminated.
  • PET polyethylene terephthalate
  • thermosetting adhesive as a sealing adhesive was uniformly applied to a thickness of 20 ⁇ m along the bonding surface (glossy surface) of the aluminum foil of the sealing substrate using a dispenser. This was dried under a vacuum of 100 Pa or less for 12 hours. Furthermore, the sealing substrate is moved to a nitrogen atmosphere with a dew point temperature of ⁇ 80° C. or less and an oxygen concentration of 0.8 ppm, and dried for 12 hours or more, and the moisture content of the sealing adhesive is adjusted to 100 ppm or less. did.
  • thermosetting adhesive an epoxy-based adhesive mixed with the following (A) to (C) was used.
  • the above-mentioned sealing substrate was placed in close contact with the above-mentioned laminate, and was tightly sealed using a pressure roll under pressure conditions of a pressure roll temperature of 100°C, a pressure of 0.5 MPa, and an apparatus speed of 0.3 m/min.
  • an organic EL element 100A having the same configuration as the organic EL element having the configuration shown in FIG. 1 was manufactured.
  • NPB N,N'-bis(naphthalen-1-yl)N,N'-bis(phenyl)-benzidine
  • a device for hole mobility measurement also referred to as a “hole-only device” 100H was manufactured in the same manner, except for the above. Since NPB is a hole-transporting material, injection of electrons from the cathode does not occur, so it can be used for measuring hole mobility.
  • An electron mobility measuring device 100E was fabricated in the same manner as in the production of the organic EL device 100A, except that calcium was vapor-deposited to a thickness of 5 nm before forming the light-emitting layer. Calcium is an electron-injecting material and can be used for electron mobility measurement because it does not cause hole injection due to the large gap to the light-emitting layer HOMO.
  • Organic EL element 100B was produced in the same manner as in the production of organic EL element 100A under the inert gas, except that air (temperature 20° C.; humidity 50%) was used as the atmosphere for film formation of the light-emitting layer.
  • each organic EL device was manufactured in the same manner except that the type of polymer in the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as shown in Tables I and II.
  • Device B (101B-130B) was manufactured.
  • Organic EL devices A and B produced by the above method were evaluated as follows.
  • Organic EL devices H and E fabricated under an inert gas were used to calculate the absolute value of the difference between the common logarithms of hole mobility and electron mobility.
  • J (9/8) ⁇ 0 ⁇ (V 2 /L 3 )
  • J is the space charge limited current
  • ⁇ is the dielectric constant of the organic thin film
  • ⁇ 0 is the vacuum dielectric constant
  • J is the current density
  • V is the applied voltage.
  • the measured values J and V are plotted to plot J on the vertical axis and V on the horizontal axis.
  • the electron mobility ⁇ e and the hole mobility ⁇ h of each organic EL element are calculated from the slope a of the straight line, and the difference between the common logarithms of each organic EL element ( log[electron mobility ⁇ e ] ⁇ log[hole mobility ⁇ h ]) was obtained.
  • the organic EL devices of the present invention of Examples are superior to the organic EL devices of Comparative Examples in terms of luminous efficiency and driving life, and are capable of suppressing deterioration in performance during production in air. I understand.
  • an organic EL device having a light-emitting layer containing a polymer with a conductivity of 1 [S/m] or less is an organic EL device that does not.
  • the relative values of the EQE ratio and LT ratio under inert gas are high, and the decrease in these values is suppressed.
  • Example 2 ⁇ Production of organic EL element under inert gas> ⁇ Production of Organic EL Element A (200A)>>
  • the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as follows, and the solid content ratio (parts by mass) of the polymer, the host compound, and the light-emitting dopant was changed to
  • An organic EL device 200A was manufactured in the same manner except for the changes shown in Table III.
  • a hole mobility measuring device 200H was manufactured in the same manner as the organic EL device 100H.
  • each organic EL element B (201B) was manufactured in the same manner except that the type of polymer in the coating liquid for forming the light emitting layer in the formation of the light emitting layer was changed as shown in Table III. ⁇ 213B), H (201H-213H) and E (201E-213E) were prepared.
  • the organic EL devices of Examples of the present invention are superior to the organic EL devices of Comparative Examples in luminous efficiency and driving life, and It can be seen that both suppression of performance deterioration during manufacturing can be achieved.
  • Example 3 ⁇ Production of organic EL element under inert gas> ⁇ Production of organic EL elements A (300A and 301A), organic EL elements H (300B and 301B, for hole mobility measurement), and organic EL elements E (300B and 301B, for electron mobility measurement)>>>
  • the organic EL element 100A was produced in the same manner except that the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as follows and the conditions were changed to those described in Table IV.
  • EL elements A (300A and 301A), H (300H and 301H), and E (300H and 301H) were manufactured, respectively.
  • Organic EL elements B (300B and 301B) were manufactured in the same manner as in the manufacture of the organic EL elements 300A and 301A under the inert gas, except that air (50% humidity) was used as the atmosphere for film formation of the light-emitting layer.
  • the organic EL device of the present invention has excellent luminous efficiency and drive life due to the fact that the polymer is a mixture of components with different stereoregularities, and suppresses performance deterioration during manufacturing in the atmosphere. and can be further compatible.
  • Example 4 ⁇ Production of organic EL element under inert gas> ⁇ Production of Organic EL Element A (400A)>>
  • the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as follows, and the solid content ratio (parts by mass) of the polymer, host compound, and light-emitting dopant was changed as shown in Table V.
  • An organic EL device 400A was manufactured in the same manner except for the changes.
  • a hole mobility measuring device 400H was manufactured in the same manner as the organic EL device 100H.
  • Organic EL element 400B was produced in the same manner as in the production of organic EL element 400A under the inert gas, except that air (50% humidity) was used as the atmosphere for film formation of the light-emitting layer.
  • each organic EL element B (401B ⁇ 407B), H (401H-407H) and E (401E-407E) were prepared.
  • the problems of the present invention can be solved by controlling the difference between the hole mobility and the electron mobility with the charge-transporting host compound, the light-emitting dopant, the polymer, etc. contained in the light-emitting layer. That is, an organic electroluminescence element that has high luminous efficiency, has a long life, can suppress performance deterioration during manufacturing in the atmosphere, and can be manufactured at low cost, a method for manufacturing the same, a lighting device, and a display Equipment can be provided.
  • An organic electroluminescence element that has high luminous efficiency, has a long life, can suppress deterioration in performance during manufacturing in the atmosphere, and can be manufactured at low cost, a method for manufacturing the same, and a lighting device equipped with the same , a display device and a printed model can be provided.

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Abstract

The present invention provides: an organic electroluminescent element which is able to be produced at low cost, while having a high luminous efficiency and a long service life, and which is able to be suppressed in the performance deterioration during the production in the atmosphere; a method for producing this organic electroluminescent element; a lighting device; a display device; and a printed model which comprises this organic electroluminescent element, this lighting device or this display device.　An organic electroluminescent element which comprises, at least on a substrate, an image display part that is held between a positive electrode and a negative electrode facing each other, and which is characterized in that: the image display part is composed of a light emitting image display part and a non-light emitting image display part; the light emitting image display part comprises at least an electrode and a light emitting layer that is adjacent to a charge injection layer or a charge transport layer; the light emitting layer contains a polymer that has an electrical conductivity of 1 (S/m) or less, a charge transport host compound and a light emitting dopant; the mass ratio of the polymer is within the range of 5 to 80 if the total mass of the light emitting layer is taken as 100; and the absolute value of the difference between the common logarithms of the hole mobility and the electron mobility of the light emitting layer is 4.5 or less.

Description

有機エレクトロルミネッセンス素子、その製造方法、並びにそれを具備した照明装置、表示装置及び印刷造形物ORGANIC ELECTROLUMINESCENT DEVICE, MANUFACTURING METHOD THEREOF, AND LIGHTING DEVICE, DISPLAY DEVICE AND PRINTED MODEL COMPRISING THE SAME
　本発明は、有機エレクトロルミネッセンス素子、その製造方法、並びにそれを具備した照明装置、表示装置及び印刷造形物に関する。より詳しくは、発光効率が高く、長寿命で、かつ、大気下での製造時の性能低下を抑制可能であり、低コストにて製造可能である有機エレクトロルミネッセンス素子等に関する。 The present invention relates to an organic electroluminescence element, a method for manufacturing the same, and a lighting device, a display device, and a printed product having the same. More specifically, it relates to an organic electroluminescence element or the like that has high luminous efficiency, has a long life, can suppress deterioration in performance during manufacturing in the atmosphere, and can be manufactured at low cost.
　有機エレクトロルミネッセンス素子（ｏｒｇａｎｉｃ　ｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｔ　ｄｅｖｉｃｅ（ｏｒ　ｄｉｏｄｅ）；「有機ＥＬ素子」ともいう。）は、発光する化合物を含有する層を陰極と陽極で挟んだ構成を有し、電界印加により、陽極から注入される正孔と陰極から注入される電子が再結合して励起子（エキシトン）を生成し、この励起子が失活する際の光（電磁波）の放出を利用した素子である。 An organic electroluminescent device (or diode; also referred to as an "organic EL element") has a structure in which a layer containing a light-emitting compound is sandwiched between a cathode and an anode. It is a device that utilizes the recombination of the holes injected from the cathode and the electrons injected from the cathode to generate excitons, and the emission of light (electromagnetic waves) when the excitons are deactivated.
　有機エレクトロルミネッセンス素子の面発光源としての魅力が高まるにつれ、より高効率、長寿命、及び低コストの全てを満足させる性能の有機ＥＬ素子が必要とされている。 As the attractiveness of organic electroluminescence elements as surface light sources increases, there is a need for organic EL elements with performance that satisfies all of higher efficiency, longer life, and lower cost.
　また、光源として用いた際に、薄い、軽い、又は曲がるといった有機ＥＬ素子の魅力を最大限に発揮するため、フレキシブルパネル上に有機ＥＬ素子を形成したフレキシブルディスプレイやフレキシブル照明等の形態への開発が進められている。 In addition, in order to maximize the attractiveness of organic EL elements such as being thin, light, and flexible when used as a light source, we are developing forms such as flexible displays and flexible lighting in which organic EL elements are formed on flexible panels. is in progress.
　上記の性能及び形態への要求に対して、蒸着法によりフレキシブルバリア基板上に各機能材料を多積層形成する方法がある。
　しかしながら、蒸着法は、高い真空度を実現するための製造設備や材料利用効率の低さから、製造コストが高くなる問題がある。
　また、蒸着法は、材料混合数に制限があり、層ごとに材料を変えて機能分離しながら積層する必要があることから、プロセス工数及び蒸着時間の増加による更なるコストアップを招いていた。 In response to the above requirements for performance and form, there is a method of forming multiple layers of each functional material on a flexible barrier substrate by vapor deposition.
However, the vapor deposition method has a problem of high manufacturing cost due to the low efficiency of manufacturing equipment and materials used to achieve a high degree of vacuum.
In addition, the vapor deposition method has a limit on the number of materials to be mixed, and it is necessary to layer the layers while separating the functions by changing the material for each layer.
　その一方で、製造コストの低減及び製造プロセスをシンプルにする方法として、湿式法（「塗布法」ともいう。）により各機能材料を積層する方法がある。 On the other hand, as a method of reducing manufacturing costs and simplifying the manufacturing process, there is a method of laminating each functional material by a wet method (also called a "coating method").
　例えば非特許文献１では、絶縁バンク内にポリマー発光材料をインクジェット印刷により射出し、マルチカラーピクセルを実現した有機ＥＬ表示装置の例が開示されている。 For example, Non-Patent Document 1 discloses an example of an organic EL display device in which a multi-color pixel is realized by injecting a polymer light-emitting material into an insulating bank by inkjet printing.
　しかしながら、有機ＥＬ表示装置（ディスプレイ）に代表される表示装置の上記製法は、バンクの事前形成や高度なアライメント技術が必要不可欠であり、オンデマンド化の潮流に伴った少量多品種／低コスト製造への期待には応えていなかった。 However, the above-mentioned manufacturing method of the display device represented by the organic EL display device (display) requires pre-formation of the bank and advanced alignment technology. did not meet expectations.
　上記のような有機ＥＬ素子を実現する一つの製法として、パターン化した製法による有機ＥＬ素子（「パターン化ＯＬＥＤ」ともいう。）が挙げられる。
　非特許文献２では、インクジェット印刷法により、事前のバンク形成無しで２００μｍのドットがパターニングされた有機ＥＬ素子が開示されている。
　当該有機ＥＬ素子の作製では、絶縁性のポリマーであるポリメチルメタクリレート（ＰＭＭＡ）がインク受容層としてスピンコートされ、前記受容層における画像部には加えてホスト化合物と発光材料がインクジェットを用いて印字され、受容層のみで形成された絶縁非画像部と導電発光材料が射出混合された発光画像部の形成を実現している。
　発光材料としては、通常２０％程度の外部量子効率を見込めるリン光発光性化合物、例えばＩｒ（ｐｐｙ）３を用いているが、発光部の外部量子効率は３．１％程度に留まっており、更なる改良が必要とされていた。 As one manufacturing method for realizing the organic EL element as described above, there is an organic EL element (also referred to as “patterned OLED”) by a patterned manufacturing method.
Non-Patent Document 2 discloses an organic EL device in which dots of 200 μm are patterned by an inkjet printing method without prior formation of banks.
In the fabrication of the organic EL device, polymethyl methacrylate (PMMA), an insulating polymer, is spin-coated as an ink-receiving layer, and a host compound and a light-emitting material are printed using inkjet printing on the image area of the receiving layer. It realizes the formation of the luminescent image area in which the conductive luminescent material is injected and mixed with the insulating non-image area formed only by the receiving layer.
As the light-emitting material, a phosphorescent compound such as Ir(ppy) 3 , which can be expected to have an external quantum efficiency of about 20%, is usually used, but the external quantum efficiency of the light-emitting part remains at about 3.1%. Further improvements were needed.
　一方、従来使用されてきた真空や不活性ガス環境を製造に使用しないことが製造コストを下げるために求められてきている。
　例えば低コスト製造実現のためには、大気下での製造に対する安定性が重要となるが、前記非特許文献２に開示されている技術では、画像部の駆動安定性は不十分であり、更なる改良が不可欠である。 On the other hand, in order to reduce the manufacturing cost, it is required not to use the conventionally used vacuum or inert gas environment for manufacturing.
For example, in order to realize low-cost manufacturing, stability in manufacturing under the atmosphere is important. Further improvements are essential.
　本発明は、上記問題・状況に鑑みてなされたものであり、その解決課題は、発光効率が高く、長寿命で、かつ、大気下での製造時の性能低下を抑制可能であり、低コストにて製造可能である有機エレクトロルミネッセンス素子及びその製造方法、並びにそれを具備した照明装置、表示装置及び印刷造形物を提供することである。 The present invention has been made in view of the above problems and circumstances, and the problem to be solved is that the luminous efficiency is high, the life is long, and the deterioration of performance during manufacturing in the atmosphere can be suppressed, and the cost is low. It is an object of the present invention to provide an organic electroluminescence element that can be manufactured by the method, a method for manufacturing the same, and an illumination device, a display device, and a printed product having the same.
　本発明者は、上記課題を解決すべく、上記問題の原因等について検討した結果、発光層に含有させる電荷輸送性ホスト化合物、発光性ドーパント及びポリマー等により、正孔移動度と電子移動度の常用対数値の差を制御することにより、上記課題が達成可能であることを見出し本発明に至った。
　すなわち、本発明に係る上記課題は、以下の手段により解決される。 In order to solve the above problems, the present inventors have investigated the causes of the above problems and found that the charge-transporting host compound, the luminescent dopant, the polymer, etc. contained in the light-emitting layer can improve the hole mobility and the electron mobility. The inventors have found that the above object can be achieved by controlling the difference between the common logarithms, and have completed the present invention.
That is, the above problems related to the present invention are solved by the following means.
　１．少なくとも基板上に、対向する陽極と陰極に挟持された画像表示部とを有する有機エレクトロルミネッセンス素子であって、
　前記画像表示部が、発光画像表示部と非発光画像表示部で構成され、
　前記発光画像表示部が、少なくとも電極、電荷注入層又は電荷輸送層に隣接する発光層を有し、
　前記発光層が、少なくとも導電率が１［Ｓ／ｍ］以下のポリマー、電荷輸送性ホスト化合物及び発光性ドーパントを含有し、かつ、
　前記発光層の正孔移動度と電子移動度の常用対数値の差の絶対値が、４．５以下である
ことを特徴とする有機エレクトロルミネッセンス素子。 1. An organic electroluminescence element having an image display portion sandwiched between an anode and a cathode facing each other on at least a substrate,
wherein the image display section is composed of a luminescent image display section and a non-luminescent image display section,
The light-emitting image display section has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer,
The light-emitting layer contains at least a polymer having a conductivity of 1 [S/m] or less, a charge-transporting host compound, and a light-emitting dopant, and
An organic electroluminescence device, wherein the absolute value of the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is 4.5 or less.
　２．前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が、３．５以下である
ことを特徴とする第１項に記載の有機エレクトロルミネッセンス素子。 2. 2. The organic electroluminescence device according to claim 1, wherein the absolute value of the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is 3.5 or less.
　３．前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が、２．５以下である
ことを特徴とする第１項又は第２項に記載の有機エレクトロルミネッセンス素子。 3. 3. The organic electroluminescence device according to claim 1 or 2, wherein the absolute value of the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is 2.5 or less.
　４．前記発光層の総質量を１００とした場合の前記ポリマーの質量比率が、５～８０質量％の範囲内である
ことを特徴とする第１項から第３項までのいずれか一項に記載の有機エレクトロルミネッセンス素子。 4. 3. The polymer according to any one of items 1 to 3, wherein the mass ratio of the polymer is in the range of 5 to 80% by mass when the total mass of the light-emitting layer is 100. Organic electroluminescence device.
　５．前記ポリマーが、ベンゼン環を含むポリマーである
ことを特徴とする第１項から第４項までのいずれか一項に記載の有機エレクトロルミネッセンス素子。 5. 5. The organic electroluminescence device according to any one of items 1 to 4, wherein the polymer is a polymer containing a benzene ring.
　６．前記ベンゼン環を含むポリマーが、非共役ポリマーである
ことを特徴とする第５項に記載の有機エレクトロルミネッセンス素子。 6. 6. The organic electroluminescence device according to item 5, wherein the polymer containing a benzene ring is a non-conjugated polymer.
　７．前記非共役ポリマーが、ベンゼン環を側鎖として含む
ことを特徴とする第６項に記載の有機エレクトロルミネッセンス素子。 7. 7. The organic electroluminescence device according to item 6, wherein the non-conjugated polymer contains a benzene ring as a side chain.
　８．前記非共役ポリマーが、ポリスチレンである
ことを特徴とする第６項又は第７項に記載の有機エレクトロルミネッセンス素子。 8. 8. The organic electroluminescence device according to item 6 or 7, wherein the non-conjugated polymer is polystyrene.
　９．前記非共役ポリマーが、ポリスチレン誘導体である
ことを特徴とする第６項又は第７項に記載の有機エレクトロルミネッセンス素子。 9. 8. The organic electroluminescence device according to item 6 or 7, wherein the non-conjugated polymer is a polystyrene derivative.
　１０．前記ポリスチレン誘導体が、ポリビニルフェノールである
ことを特徴とする第９項に記載の有機エレクトロルミネッセンス素子。 10. 10. The organic electroluminescence device according to item 9, wherein the polystyrene derivative is polyvinylphenol.
　１１．前記非共役ポリマーが、立体規則性の異なる成分の混合物である
ことを特徴とする第６項から第１０項までのいずれか一項に記載の有機エレクトロルミネッセンス素子。 11. 11. The organic electroluminescence device according to any one of items 6 to 10, wherein the non-conjugated polymer is a mixture of components with different stereoregularities.
　１２．前記発光層が、電荷注入層に直接隣接する
ことを特徴とする第１項から第１１項までのいずれか一項に記載の有機エレクトロルミネッセンス素子。 12. 12. The organic electroluminescence device according to any one of items 1 to 11, wherein the light-emitting layer is directly adjacent to the charge injection layer.
　１３．前記発光層が、電極に直接隣接する
ことを特徴とする第１項から第１１項までのいずれか一項に記載の有機エレクトロルミネッセンス素子。 13. 12. The organic electroluminescence device according to any one of items 1 to 11, wherein the light-emitting layer is directly adjacent to the electrode.
　１４．第１項から第１３項までのいずれか一項に記載の有機エレクトロルミネッセンス素子を製造する有機エレクトロルミネッセンス素子の製造方法であって、
　前記発光層を、インクジェット印刷法によって形成する工程を有する
ことを特徴とする有機エレクトロルミネッセンス素子の製造方法。 14. A method for producing an organic electroluminescence device for producing the organic electroluminescence device according to any one of items 1 to 13,
A method for producing an organic electroluminescence device, comprising a step of forming the light-emitting layer by an inkjet printing method.
　１５．前記発光層を、大気下で、インクジェット印刷法によって形成する工程を有する
ことを特徴とする第１４項に記載の有機エレクトロルミネッセンス素子の製造方法 15. Item 14. The method for producing an organic electroluminescence element according to Item 14, comprising a step of forming the light-emitting layer by an inkjet printing method in the atmosphere.
　１６．第１項から第１３項までのいずれか一項に記載の有機エレクトロルミネッセンス素子を備えている
ことを特徴とする照明装置。 16. A lighting device comprising the organic electroluminescence element according to any one of items 1 to 13.
　１７．第１項から第１３項までのいずれか一項に記載の有機エレクトロルミネッセンス素子を備えている
ことを特徴とする表示装置。 17. A display device comprising the organic electroluminescence element according to any one of items 1 to 13.
　１８．第１項から第１３項までのいずれか一項に記載の有機エレクトロルミネッセンス素子を備えている
ことを特徴とする印刷造形物。 18. A printed modeled article comprising the organic electroluminescence element according to any one of items 1 to 13.
　本発明の上記手段により、発光効率が高く、長寿命で、かつ、大気下での製造時の性能低下を抑制可能であり、低コストにて製造可能である有機エレクトロルミネッセンス素子及びその製造方法、並びにそれを具備した照明装置、表示装置及び印刷造形物を提供することができる。
　本発明の効果の発現機構ないし作用機構については、明確にはなっていないが、以下のように推察している。 By the above-described means of the present invention, an organic electroluminescent element that has high luminous efficiency, has a long life, can suppress performance deterioration during manufacturing in the atmosphere, and can be manufactured at low cost, and a method for manufacturing the same. and a lighting device, a display device, and a printed product having the same.
Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows.
　本発明では、発光層に含有させる電荷輸送性ホスト化合物、発光性ドーパント及びポリマー等により、発光層の正孔移動度と電子移動度の常用対数値の差を特定値以下に制御することにより前記課題を解決することができたと推察される。
　以下の説明は、上記正孔移動度と電子移動度の差を制御して得られた効果の発現機構を考察したものであり、必ずしも明確にはなっていない。
　従って、本発明の効果の発現機構は、下記推察機構に限定されるものではない。 In the present invention, the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is controlled to a specific value or less by using a charge-transporting host compound, a light-emitting dopant, a polymer, or the like contained in the light-emitting layer. It is presumed that the problem was solved.
The following explanation considers the manifestation mechanism of the effect obtained by controlling the difference between the hole mobility and the electron mobility, and is not necessarily clear.
Therefore, the expression mechanism of the effect of the present invention is not limited to the speculated mechanism below.
　有機ＥＬ素子の発光層にポリメチルメタクリレート（ＰＭＭＡ）のような通常の絶縁性ポリマーを使用した場合、ポリマーは主に層内に分散又は層中に凝集することになり、電流の流れが抑制される又は道筋（導電パス）が遮断される。
　また、ポリマーに押し出される形で電荷輸送性ホスト化合物及び発光性ドーパントが凝集し、導電性の低下、界面再結合及び再結合確率の低下を引き起こす。
　本発明では、導電率が１［Ｓ／ｍ］以下のポリマー（以下において、単に「ポリマー」ともいう。）が隣接層界面に局在することでキャリアバランス性と各種ブロック性を発現していることが示唆された。 When an ordinary insulating polymer such as polymethyl methacrylate (PMMA) is used in the light-emitting layer of an organic EL element, the polymer mainly disperses or agglomerates in the layer, suppressing current flow. or the route (conductive path) is blocked.
In addition, the charge-transporting host compound and the light-emitting dopant aggregate in the form of being extruded into the polymer, causing a decrease in conductivity, interfacial recombination, and a decrease in recombination probability.
In the present invention, a polymer having a conductivity of 1 [S/m] or less (hereinafter also simply referred to as "polymer") is localized at the interface between adjacent layers, thereby exhibiting carrier balance and various block properties. It has been suggested.
　本発明では、このポリマー局在化に着目し検討を進めたところ、発光層にポリマーを用いることで、正孔－電子移動度差を更に縮小でき、結果として、成膜乾燥時の大気の影響を受けやすい界面での発光確率を抑制して、高効率、長寿命及び大気下での製造安定効果を発現すると考えられる。 In the present invention, we focused on this polymer localization and investigated, and found that by using a polymer in the light-emitting layer, the hole-electron mobility difference can be further reduced, and as a result, the influence of the atmosphere during drying of the film. It is thought that by suppressing the luminous probability at the interface which is susceptible to light emission, the effects of high efficiency, long life, and production stability in the atmosphere are exhibited.
　上記機能の発現機構の詳細は、いまだ明らかではないが、次のように推察している。
　（１）上記ポリマーによるホスト化合物及びドーパントの分散効果があり、これらの分子間を伝わる電荷キャリアが結晶粒界（グレインバンダリー）において捕獲（トラップ）されることを抑制する効果と、これらのキャリアが発光層を突き抜けてしまうことを抑制するキャリアブロック効果との両立が可能となる。 Although the details of the expression mechanism of the above function are not yet clear, it is speculated as follows.
(1) The above polymer has the effect of dispersing the host compound and the dopant, and has the effect of suppressing the trapping of charge carriers traveling between these molecules at the grain boundary, and the effect of suppressing the trapping of these carriers. It is possible to achieve compatibility with the carrier block effect that suppresses penetration of the light-emitting layer.
　（２）ポリマーが電極界面に局在した場合でも、トンネル機構を介して注入は可能であり、注入された電荷キャリアに対してはブロック又は輸送性の調整剤として働くと考えられる。
　その結果、発光層内での再結合確率が上がり、効率、寿命が向上する。 (2) Even if the polymer is localized at the electrode interface, it is possible to inject via a tunneling mechanism and is believed to act as a block or transport modifier for the injected charge carriers.
As a result, the probability of recombination in the light-emitting layer is increased, and the efficiency and life are improved.
　（３）酸素又は水分子が発光材料に近接する場合、発光材料が駆動時に酸化されて発光クエンチャー（「消光剤」ともいう。）となることが推察され、当該ポリマーにはその発生確率が最も高い発光層界面での再結合を抑制する効果がある。
　特に発光層と隣接層の界面付近に局在して、正孔移動度と電子移動度の常用対数値の差の絶対値が４．５以下である場合にその効果が大きい。 (3) When oxygen or water molecules are close to the light-emitting material, it is presumed that the light-emitting material is oxidized during operation and becomes a light emission quencher (also referred to as a "quencher"), and the polymer has a high probability of occurrence. It has the highest effect of suppressing recombination at the light-emitting layer interface.
In particular, the effect is significant when the absolute value of the difference between the common logarithms of hole mobility and electron mobility is 4.5 or less, localized near the interface between the light-emitting layer and the adjacent layer.
　本発明の効果は、発光層がインクジェットなどの液滴吐出法により成膜される場合に発揮されやすい。
　液滴吐出法により成膜される場合の方が、蒸着やスピンコートなどで成膜する場合よりも成膜雰囲気の活性ガスの影響が顕著であり、発光効率の低下や短寿命化の影響をより受けやすいが、このような場合でも、性能低下を生じることなく発光する。
　従って、不活性ガスや真空設備の製造コストも下げることができる。 The effect of the present invention is likely to be exhibited when the light-emitting layer is formed by a droplet discharge method such as inkjet.
When the film is formed by the droplet discharge method, the effect of the active gas in the film formation atmosphere is more pronounced than when the film is formed by vapor deposition or spin coating, and the effect of lowering the luminous efficiency and shortening the life is reduced. Although more susceptible, it still emits light without performance degradation in such cases.
Therefore, manufacturing costs for inert gas and vacuum equipment can also be reduced.
本発明の有機ＥＬ素子の概略断面図Schematic cross-sectional view of the organic EL element of the present invention ドット状に発光画像表示部が配置されていることを表す概念図Conceptual diagram showing that light-emitting image display units are arranged in dots. 隔壁（バンク）の一例を示す断面図Sectional view showing an example of a partition (bank) インクジェット記録法による有機ＥＬ素子の作製法を示す概念図Conceptual diagram showing a method for fabricating an organic EL element using an inkjet recording method インクジェット記録法による有機ＥＬ素子の作製法を示す概念図Conceptual diagram showing a method for fabricating an organic EL element using an inkjet recording method インクジェット記録法による有機ＥＬ素子の作製法を示す概念図Conceptual diagram showing a method for fabricating an organic EL element using an inkjet recording method
　本発明の有機エレクトロルミネッセンス素子は、少なくとも基板上に、対向する陽極と陰極に挟持された画像表示部とを有する有機エレクトロルミネッセンス素子であって、前記画像表示部が、発光画像表示部と非発光画像表示部で構成され、前記発光画像表示部が、少なくとも電極、電荷注入層又は電荷輸送層に隣接する発光層を有し、前記発光層が、少なくとも導電率が１［Ｓ／ｍ］以下のポリマー、電荷輸送性ホスト化合物及び発光性ドーパントを含有し、かつ、前記発光層の正孔移動度と電子移動度の常用対数値の差の絶対値が、４．５以下であることを特徴とする。
　この特徴は、下記各実施態様（形態）に共通する又は対応する技術的特徴である。 The organic electroluminescence element of the present invention is an organic electroluminescence element having, on at least a substrate, an image display portion sandwiched between an anode and a cathode facing each other, wherein the image display portion comprises a light-emitting image display portion and a non-light-emitting portion. The light-emitting image display portion has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer, and the light-emitting layer has an electrical conductivity of at least 1 [S/m] or less. It contains a polymer, a charge-transporting host compound, and a light-emitting dopant, and the absolute value of the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is 4.5 or less. do.
This feature is a technical feature common to or corresponding to each of the following embodiments (forms).
　本発明の実施態様としては、前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が３．５以下であることが、少なくとも導電率が１［Ｓ／ｍ］以下のポリマーのブロック機能を最大限に活用し、再結合確率及び駆動寿命を向上し、大気下での製造時の影響を抑制する観点から好ましい。より好ましくは２．５以下である。 As an embodiment of the present invention, the absolute value of the difference between the common logarithm of the hole mobility and the electron mobility of the light emitting layer is 3.5 or less, and the conductivity is at least 1 [S / m] or less. It is preferable from the viewpoint of maximizing the blocking function of the polymer, improving the recombination probability and driving life, and suppressing the influence during production in the atmosphere. More preferably, it is 2.5 or less.
　前記発光層の総質量を１００とした場合の前記ポリマーの質量比率が、５～８０質量％の範囲内であることが、電荷キャリアすなわち正孔及び電子の移動度の制御の観点から好ましい。 From the viewpoint of controlling the mobility of charge carriers, that is, holes and electrons, it is preferable that the mass ratio of the polymer is in the range of 5 to 80% by mass when the total mass of the light-emitting layer is 100.
　前記ポリマーが、ベンゼン環を含むポリマーであることが、高膜密度化とキャリア輸送材料やドーパント分散化の効果を得やすい点で好ましい。 It is preferable for the polymer to be a polymer containing a benzene ring, because it is easy to obtain the effects of increasing the film density and dispersing the carrier transport material and dopant.
　前記ベンゼン環を含むポリマーが、非共役ポリマーであることが、キャリアブロックの観点で好ましく、特に隣接層に電荷ブロック層や逆電荷の輸送層を持たない場合、すなわち電極や電荷注入層に直接発光層を設置する場合に、発光内に電荷を留めて再結合確率を上げる点で好ましい。 It is preferable that the polymer containing the benzene ring is a non-conjugated polymer from the viewpoint of carrier blocking. When a layer is provided, it is preferable in terms of retaining the charge in the emitted light and increasing the recombination probability.
　前記非共役ポリマーが、ベンゼン環を側鎖として含むことが、上記高密度化及びキャリア輸送材料やドーパント分散化の効果の点で好ましい。 It is preferable that the non-conjugated polymer contains a benzene ring as a side chain in terms of the effects of increasing the density and dispersing the carrier transport material and the dopant.
　前記非共役ポリマーが、ポリスチレンであることが、両電極側界面での再結合抑制の観点で好ましい。 　It is preferable that the non-conjugated polymer is polystyrene from the viewpoint of suppressing recombination at the interface on both electrode sides.
　前記非共役ポリマーが、ポリスチレン誘導体であることが、両電極側界面での再結合抑制の点でより好ましい。 It is more preferable that the non-conjugated polymer is a polystyrene derivative from the viewpoint of suppressing recombination at the interface on both electrode sides.
　前記ポリスチレン誘導体が、ポリビニルフェノールであることが、両電極側界面での再結合抑制の点で好ましい。 It is preferable that the polystyrene derivative is polyvinyl phenol from the viewpoint of suppressing recombination at the interface on both electrode sides.
　前記非共役ポリマーが、立体規則性の異なる成分の混合物であることが、ポリマーの界面局在量を制御し、キャリアバランスの調整ができる点で好ましい。 It is preferable that the non-conjugated polymer is a mixture of components with different stereoregularities in that the amount of polymer localized at the interface can be controlled and the carrier balance can be adjusted.
　前記発光層が、電荷注入層又は電極に直接隣接することが、電荷キャリアの移動度を制御する点で好ましい。 It is preferable for the light-emitting layer to be directly adjacent to the charge injection layer or the electrode in terms of controlling the mobility of charge carriers.
　本発明の有機エレクトロルミネッセンス素子の製造方法は、前記発光層を、インクジェット印刷法によって形成する工程を有する態様の方法であることを特徴とする。また、前記発光層を、大気下で、インクジェット印刷法によって形成する工程を有することが、より好ましい。 The method for producing an organic electroluminescence element of the present invention is characterized by being a method of a mode having a step of forming the light-emitting layer by an inkjet printing method. Moreover, it is more preferable to have a step of forming the light-emitting layer by an inkjet printing method in the atmosphere.
　本発明の本発明の有機エレクトロルミネッセンス素子は、上記のように種々の特徴を有することから、照明装置や表示装置や印刷造形物に好適に用いることができる。 Since the organic electroluminescence device of the present invention has various characteristics as described above, it can be suitably used for lighting devices, display devices, and printed objects.
　以下、本発明とその構成要素、及び本発明を実施するための形態・態様について詳細な説明をする。なお、本願において、「～」は、その前後に記載される数値を下限値及び上限値として含む意味で使用する。 The following is a detailed description of the present invention, its components, and the forms and modes for carrying out the present invention. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
　≪本発明の有機エレクトロルミネッセンス素子の概要≫
　本発明の有機エレクトロルミネッセンス素子（以下、「有機ＥＬ素子」という。）は、少なくとも基板上に、対向する陽極と陰極に挟持された画像表示部とを有する有機エレクトロルミネッセンス素子であって、前記画像表示部が、発光画像表示部と非発光画像表示部で構成され、前記発光画像表示部が、少なくとも電極、電荷注入層又は電荷輸送層に隣接する発光層を有し、前記発光層が、少なくとも導電率が１［Ｓ／ｍ］以下のポリマー、電荷輸送性ホスト化合物及び発光性ドーパントを含有し、かつ、前記発光層の正孔移動度と電子移動度の常用対数値の差の絶対値が、４．５以下であることを特徴とする。 <<Overview of the organic electroluminescence element of the present invention>>
An organic electroluminescence device (hereinafter referred to as an "organic EL device") of the present invention is an organic electroluminescence device having, on at least a substrate, an image display portion sandwiched between an anode and a cathode facing each other, wherein the image The display section is composed of a light-emitting image display section and a non-light-emitting image display section, the light-emitting image display section has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer, and the light-emitting layer comprises at least The light-emitting layer contains a polymer having a conductivity of 1 [S/m] or less, a charge-transporting host compound, and a light-emitting dopant, and the absolute value of the difference between the common logarithms of hole mobility and electron mobility of the light-emitting layer is , 4.5 or less.
　本発明の実施態様としては、前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が３．５以下であることがポリマーのブロック機能を最大限に活用し、再結合確率及び駆動寿命を向上し、大気下での製造時の影響を抑制する観点から、好ましい。より好ましくは、２．５以下である。 As an embodiment of the present invention, the absolute value of the difference between the common logarithm of the hole mobility and the electron mobility of the light-emitting layer is 3.5 or less, making the most of the blocking function of the polymer and recombination It is preferable from the viewpoint of improving the probability and driving life and suppressing the influence during manufacturing in the atmosphere. More preferably, it is 2.5 or less.
　ここで、「導電率（「電気伝導率」又は「電気伝導度」ともいう。）」とは、どの程度電気を通しやすいかを表す指標となる値をいい、電気抵抗率の逆数をＳＩ系単位であるＳ／ｍ（ジーメンス毎メートル）で表すことにする。 Here, "conductivity (also referred to as "electrical conductivity" or "electrical conductivity")" refers to a value that is an indicator of how easily electricity can pass, and the reciprocal of electrical resistivity is the SI system The unit is S/m (siemens per meter).
　（電子と正孔の移動度差の評価）
　「電子及び正孔の移動度」とは、電場に応答して電荷キャリア、すなわち電子及び正孔が物質中を移動することができる容易さを表す指標となる値をいう。 (Evaluation of electron-hole mobility difference)
"Electron and hole mobility" refers to a measure of the ease with which charge carriers, ie, electrons and holes, can move through a material in response to an electric field.
　電子及び正孔の移動度の測定・評価方法としては、例えば空間電荷制限電流の電流－電圧特性から求める方法や、所定の素子にパルス光を照射し、キャリアが電極間を走行する時間から移動度を求めるＴｉｍｅ－Ｏｆ－Ｆｉｇｈｔ法による評価法や、又は、有機ＥＬ素子に交流電圧を印加した場合の、走行時間効果から移動度を求めるインピーダンス分光法による評価法等がある。 As a method for measuring and evaluating the mobility of electrons and holes, for example, a method of determining from the current-voltage characteristics of the space charge limited current, or a method of irradiating a predetermined element with pulsed light and moving the carriers from the time it takes to travel between the electrodes There is an evaluation method by the Time-Of-Fight method for obtaining mobility, or an evaluation method by impedance spectroscopy for obtaining mobility from the transit time effect when an AC voltage is applied to an organic EL element.
　本発明においては、電子及び正孔の移動度の測定については、次のようにして行う。
　すなわち、測定用試料としては、陽極と陰極の間に測定対象となる、少なくとも、電子輸送性化合物又は正孔輸送性化合物を含有する発光層を挟持した積層体からなる有機ＥＬ素子を作製する。
　次に作製した各有機ＥＬ素子の電流密度－電圧特性（「Ｊ－Ｖ特性」）についての測定値をプロットすることにより得られるグラフ及び下記理論式に基づき電子移動度及び正孔移動度を算出する。 In the present invention, the electron and hole mobilities are measured as follows.
That is, as a sample for measurement, an organic EL device composed of a laminate sandwiching a light-emitting layer containing at least an electron-transporting compound or a hole-transporting compound to be measured between an anode and a cathode is prepared.
Next, calculate the electron mobility and hole mobility based on the graph obtained by plotting the measured values of the current density-voltage characteristics (“JV characteristics”) of each organic EL element produced and the following theoretical formula. do.
　なお、電子及び正孔の移動度の測定法の詳細については、非特許文献（Ｍ．Ａ．Ｌａｍｐｅｒｔ，Ｐ．Ｍａｒｋ，Ｃｕｒｒｅｎｔ　ｉｎｊｅｃｔｉｏｎ　ｉｎ　ｓｏｌｉｄｓ　Ａｃａｄｅｍｉｃ，ＮｅｗＹｏｒｋ，１９７０）及び国際公開第２０１９／０３９１７４号を参照することができる。
　具体的な例については、後述する実施例の説明において述べる。 For details on the method for measuring the mobility of electrons and holes, see Non-Patent Document (MA Lampert, P. Mark, Current injection in solids Academic, New York, 1970) and International Publication No. 2019/039174. You can refer to it.
Concrete examples will be described in the description of the examples below.
　なお、一般に、上記電流密度－電圧特性のグラフは空間電荷制限電流様のパターンになるので、下記空間電荷制限電流（ＳＣＬＣ）の理論式に基づき、正孔移動度と電子移動度を算出し、更にそれらの常用対数値の差の絶対値を算出する。
　（式）Ｊ＝（９／８）εε０μ（Ｖ２／Ｌ３）
　（上記式中Ｊは空間電荷制限電流、εは有機薄膜の誘電率、ε０は真空の誘電率、μはキャリア移動度、Ｊは電流密度、Ｖは印加電圧である。） In general, the graph of the current density-voltage characteristics has a pattern similar to that of the space charge limited current. Furthermore, the absolute value of the difference between those common logarithms is calculated.
(Formula) J = (9/8) εε 0 µ (V 2 /L 3 )
(In the above formula, J is the space charge limited current, ε is the dielectric constant of the organic thin film, ε0 is the vacuum dielectric constant, μ is the carrier mobility, J is the current density, and V is the applied voltage.)
　具体的には、縦軸をＪ、横軸をＶとした座標系において、Ｊ及びＶ２の測定値をプロットすることによりＪ－Ｖ２のグラフを作成し、その二次曲線に対する接線の傾きａから各有機ＥＬ素子の電子移動度μｅ及び正孔移動度μｈを算出し、各有機ＥＬ素子の常用対数値の差（ｌｏｇ［電子移動度］－ｌｏｇ［正孔移動度］）、すなわち［正孔移動度］に対する［電子移動度］の比の値の常用対数値であるｌｏｇ（［電子移動度］／［正孔移動度］）の絶対値を求める。 Specifically, in a coordinate system with J on the vertical axis and V on the horizontal axis, a graph of JV 2 is created by plotting the measured values of J and V 2 , and the slope of the tangent line to the quadratic curve Calculate the electron mobility μ e and hole mobility μ h of each organic EL device from a, and the difference between the common logarithmic values of each organic EL device (log [electron mobility]−log [hole mobility]), That is, the absolute value of log([electron mobility]/[hole mobility]), which is the common logarithm of the ratio of [electron mobility] to [hole mobility], is obtained.
　本発明に係る移動度の具体的な求め方についての詳細は、実施例にて後述するが、厳密にはＳＣＬＣ方により求めたもので、誘電率を３とし、電場の影響を受けないと仮定した場合の移動度である。
　なお、本発明のように、移動度の差に注目した場合は、誘電率については議論する必要はないので省略することにする。 Details of the specific method for obtaining the mobility according to the present invention will be described later in Examples, but strictly speaking, it is obtained by the SCLC method, the dielectric constant is 3, and it is assumed that it is not affected by the electric field. This is the mobility when
Note that when attention is paid to the difference in mobility as in the present invention, there is no need to discuss the dielectric constant, so the discussion will be omitted.
　〔１〕有機エレクトロルミネッセンス素子の構成
　本発明の有機エレクトロルミネッセンス素子（以下、「有機ＥＬ素子」とも記載する。）は、基板上に、対向する陽極と陰極に挟持された画像表示部を有しており、画像表示部は、発光層を有する発光画像表示部と、非発光画像表示部とで構成される。
　発光画像表示部は、発光層の他に、電荷注入層及び電荷輸送層を有していてもよいが、高分子材料を用いた製造では、層間の材料同士が溶解しやすいため、単層ないし少数の層構成とすることが好ましく、電荷注入層及び電荷輸送層を有していなくてもよい。
　なお、本発明の有機ＥＬ素子は、非発光画像表示部も含む広義の有機ＥＬ素子を指す。 [1] Structure of Organic Electroluminescence Device The organic electroluminescence device of the present invention (hereinafter also referred to as “organic EL device”) has an image display portion sandwiched between an anode and a cathode facing each other on a substrate. The image display section is composed of a light-emitting image display section having a light-emitting layer and a non-light-emitting image display section.
The light-emitting image display section may have a charge injection layer and a charge transport layer in addition to the light-emitting layer. A small number of layers is preferable, and the charge injection layer and the charge transport layer may be omitted.
In addition, the organic EL element of the present invention refers to an organic EL element in a broad sense including a non-luminous image display portion.
　〔１．１〕発光画像表示部
　本発明の有機ＥＬ素子は、種々の形態／構成を採り得るが、例えば光を取り出す方法・形式としては、基板側から光を取り出すボトムエミッション型であることが好ましい。
　基板側から見たときに、画像が表示される仕組みとなっており、画像が表示される箇所（平面的及び立体的構造を含む。）を「画像表示部」という。 [1.1] Light Emitting Image Display Unit The organic EL device of the present invention can take various forms/configurations. For example, the method and format for extracting light is a bottom emission type that extracts light from the substrate side. preferable.
When viewed from the substrate side, an image is displayed, and the part where the image is displayed (including planar and three-dimensional structures) is called an "image display part".
　本発明に係る画像表示部が有する「発光画像表示部」とは、例えば発光画素をドットの形状にした場合、図２に示す個々のドット自体及びその集合体をいう。
　なお、発光画素は、共通の電極に挟持される「発光層」等の機能層で構成される。
　また、当該「発光画素」は、発光することによって、色情報（色調や階調）を発現する最小要素である。
　なお、本明細書では、「発光画素」は、「発光ドット」、「ドット発光画像」又は簡単に「ドット」ともいう。 The "luminescence image display section" of the image display section according to the present invention refers to individual dots themselves and aggregates thereof shown in FIG.
The light-emitting pixel is composed of a functional layer such as a "light-emitting layer" sandwiched between common electrodes.
Also, the "light-emitting pixel" is a minimum element that expresses color information (color tone and gradation) by emitting light.
In this specification, the "light-emitting pixels" are also referred to as "light-emitting dots", "dot light-emitting images", or simply "dots".
　本発明に係る発光画像表示部は、平面状の基板にドットやベタで形成されても良いし、湾曲基板や伸縮基板等の表面に形成された三次元構造を形成しても良いし、シート状材料以外の三次元構造内にバンク材や封止材で埋め込んでも良い。
　当該発光画素は、非発光画像表示部である隔壁構造で仕切られており、さらに、当該隔壁は絶縁性層であることが好ましい。 The light-emitting image display unit according to the present invention may be formed by dots or a solid pattern on a planar substrate, may be formed by a three-dimensional structure formed on the surface of a curved substrate, an elastic substrate, or the like, or may be formed by a sheet. A bank material or a sealing material may be embedded in a three-dimensional structure other than the shape material.
The luminous pixels are partitioned by a partition structure that is a non-luminous image display portion, and the partition is preferably an insulating layer.
　本発明に係る発光層をドット状に形成する際には、パターニング可能であることが望ましい。
　パターニング開口部のあるマスクを用いた印刷法であっても良いが、非発光層への損傷（ダメージ）が少ないという観点から非接触で形成する方法が望ましい。
　また、高解像度化が可能となるという観点から、ディスペンサー法又はインクジェット印刷法がより好ましい。 When the light-emitting layer according to the present invention is formed in dots, it is desirable that patterning is possible.
A printing method using a mask having patterning openings may be used, but a non-contact method is preferable from the viewpoint of less damage to the non-light-emitting layer.
Moreover, the dispenser method or the inkjet printing method is more preferable from the viewpoint of enabling high resolution.
　なお、ドットの大きさは、発光層の主たる発光面側から撮影した光学顕微鏡写真（平面図）に基づいて計測した場合、円換算粒径として、３０～３００μｍの範囲内であることが好ましい。 The size of the dots is preferably within the range of 30 to 300 μm as a circle-equivalent particle size when measured based on an optical microscope photograph (plan view) taken from the main light-emitting surface side of the light-emitting layer.
　本発明の有機ＥＬ素子の構成について、図１を参照して説明する。
　図１は、本発明に係る発光画像表示部を構成する有機ＥＬ素子の一例を示す概略断面図である。 The structure of the organic EL element of the present invention will be described with reference to FIG.
FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element that constitutes a light-emitting image display section according to the present invention.
　有機ＥＬ素子１０は、基板１１、陽極１２、正孔注入層１３、正孔輸送層１４、発光層１５、電子輸送層１６、電子注入層１７及び陰極１８をこの順に備えている。 The organic EL element 10 includes a substrate 11, an anode 12, a hole injection layer 13, a hole transport layer 14, a light emitting layer 15, an electron transport layer 16, an electron injection layer 17 and a cathode 18 in this order.
　以上のようにして、発光層１５は共通のホスト化合物を含有し、絶縁性層（バンク）２の間に青色（Ｂ）発光画素２１、緑色（Ｇ）発光画素２２及び赤色（Ｒ）発光画素２３を有する有機ＥＬ素子１０となる。
　なお、上記正孔注入層から電子注入層までを「有機機能層」ともいう。 As described above, the light-emitting layer 15 contains a common host compound, and the blue (B) light-emitting pixel 21, the green (G) light-emitting pixel 22 and the red (R) light-emitting pixel are arranged between the insulating layers (banks) 2. The organic EL element 10 having 23 is obtained.
The layer from the hole injection layer to the electron injection layer is also called an "organic functional layer".
　図２は、本発明に係る発光画像表示部に発光画素を構成する狭義の有機ＥＬ素子がドット状に配置されていることを表す概念図である。
　すなわち、図２は、視認側から見た画像表示部の概念図（平面図）である。
　図２において、黒いドットで示されている箇所が「発光画像表示部」であり、その他の白い箇所が「非発光画像表示部」である。 FIG. 2 is a conceptual diagram showing that narrowly-defined organic EL elements forming light-emitting pixels are arranged in dots in a light-emitting image display section according to the present invention.
That is, FIG. 2 is a conceptual diagram (plan view) of the image display unit viewed from the viewing side.
In FIG. 2, portions indicated by black dots are "luminous image display portions", and other white portions are "non-luminous image display portions".
　本発明の有機ＥＬ素子の表面に対して水平方向の断面から見たとき、図２に示すように、ドット状に前記発光層１５（発光領域）が配置され、複数のドットからなる線や種々の図形を描くことができるように配置されていることが画像表示の観点から好ましい。
　また、当該ドットは、画像表示装置における画像を通常の目視による観察法で見た場合において、ドットとして視認できないような微小な画素として形成・配置されていることも好ましい。 When viewed from the cross section in the horizontal direction with respect to the surface of the organic EL element of the present invention, as shown in FIG. From the viewpoint of image display, it is preferable to arrange such that a figure can be drawn.
Also, the dots are preferably formed and arranged as minute pixels that cannot be visually recognized as dots when the image on the image display device is observed by a normal visual observation method.
　なお、図２において、ドットを除く箇所が非発光画像表示部である。
　非発光画像表示部は、発光層さえ有していなければ、発光に寄与しない。すなわち、非発光性であるため、発光画像表示部において、発光層の代わりに絶縁層とし、その他の層構成は同一としてもよい。 In FIG. 2, portions other than dots are non-luminous image display portions.
A non-light-emitting image display portion does not contribute to light emission unless it has a light-emitting layer. That is, since it is non-luminous, in the light-emitting image display portion, an insulating layer may be used instead of the light-emitting layer, and other layer configurations may be the same.
　本来、非発光画像表示部は、発光性の発現に寄与する要素を有する必要はないが、発光層以外の層を発光画像表示部と同一層とすることで、一様の塗布等により形成でき、製造しやすい。また、発光層の代わりに絶縁層とすることにより、電子や正孔すなわち電荷キャリアが入り込むのを防ぐことができる。 Originally, the non-light-emitting image display portion does not need to have elements that contribute to the expression of light-emitting properties, but by using the same layer as the light-emitting image display portion for the layers other than the light-emitting layer, the non-light-emitting image display portion can be formed by uniform coating or the like. , easy to manufacture. Also, by using an insulating layer instead of the light-emitting layer, it is possible to prevent electrons and holes, ie charge carriers, from entering.
　有機ＥＬ素子の素子構成としては、図１に示す構成例に限られるものではなく、例えば代表的な素子構成の層構成として以下の構成を挙げることができる。
　本発明に係る電荷注入層とは、正孔注入層及び電子注入層を指し、電荷輸送層とは、正孔輸送層及び電子輸送層を指す。 The element structure of the organic EL element is not limited to the structural example shown in FIG.
A charge injection layer according to the present invention refers to a hole injection layer and an electron injection layer, and a charge transport layer refers to a hole transport layer and an electron transport layer.
　（１）陽極／発光層／陰極
　（２）陽極／正孔輸送層／発光層／陰極
　（３）陽極／正孔輸送層／発光層／電子輸送層／陰極
　（４）陽極／正孔輸送層／発光層／電子輸送層／電子注入層／陰極
　（５）陽極／正孔注入層／発光層／電子輸送層／陰極
　（６）陽極／正孔注入層／正孔輸送層／発光層／電子注入層／陰極
　（７）陽極／正孔注入層／発光層／電子注入層／陰極
　（８）陽極／正孔注入層／正孔輸送層／発光層／電子輸送層／陰極
　（９）陽極／正孔注入層／正孔輸送層／発光層／電子輸送層／電子注入層／陰極
　上記の中で（１）及び（５）～（７）の構成が好ましく用いられるが、これに限定されるものではない。 (1) Anode/light-emitting layer/cathode (2) Anode/hole-transporting layer/light-emitting layer/cathode (3) Anode/hole-transporting layer/light-emitting layer/electron-transporting layer/cathode (4) Anode/hole-transporting layer /light emitting layer/electron transport layer/electron injection layer/cathode (5) anode/hole injection layer/light emitting layer/electron transport layer/cathode (6) anode/hole injection layer/hole transport layer/light emitting layer/electron injection layer/cathode (7) anode/hole injection layer/light emitting layer/electron injection layer/cathode (8) anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/cathode (9) anode/ Hole injection layer/hole transport layer/luminescent layer/electron transport layer/electron injection layer/cathode Of the above, the configurations (1) and (5) to (7) are preferably used, but are limited to these. not a thing
　本発明では、発光層が、電荷注入層に直接隣接する又は電極に直接隣接する構成であることが、電荷キャリアの移動度の制御の点で好ましい。 In the present invention, it is preferable that the light-emitting layer is directly adjacent to the charge injection layer or directly adjacent to the electrode from the viewpoint of controlling the mobility of charge carriers.
　（発光画像表示部の構成要素）
　〔１．１．１〕発光層
　発光層は、電極又は隣接層から注入される電子と正孔とが再結合し、励起子を経由して発光する場を提供する層である。当該発光層は、単層又は複数層で構成される。
　すなわち、有機ＥＬ素子は、電圧をかけると発光する有機発光材料を利用した素子である。電圧をかけることにより、電子と正孔が発光層で再結合し、このときに生成される励起子（エキシトン）が、失活し、基底状態に戻る際に放出する光（電磁波）を利用したものである。 (Constituent elements of luminescent image display unit)
[1.1.1] Light-Emitting Layer The light-emitting layer is a layer that provides a field for recombination of electrons and holes injected from an electrode or an adjacent layer to emit light via excitons. The light-emitting layer is composed of a single layer or multiple layers.
That is, the organic EL element is an element using an organic light-emitting material that emits light when a voltage is applied. By applying a voltage, electrons and holes recombine in the light-emitting layer, and the excitons (excitons) generated at this time are deactivated, and light (electromagnetic waves) emitted when returning to the ground state is used. It is.
　本発明に係る発光層は、少なくとも導電率が１［Ｓ／ｍ］以下のポリマー（「バインダー」、「ホストポリマー」ともいう。）、電荷輸送性ホスト化合物（「マトリックス材料」、「発光ホスト化合物」、又は単に「ホスト」ともいう。）及び発光性ドーパント（「発光性ドーパント」、又は単に「ドーパント」ともいう。）を含有し、かつ、前記発光層の正孔移動度と電子移動度の常用対数値の差の絶対値が、すなわち［正孔移動度］に対する［電子移動度］の比の値の常用対数値であるｌｏｇ（［電子移動度］／［正孔移動度］）の絶対値が４．５以下である。 The light-emitting layer according to the present invention includes at least a polymer having a conductivity of 1 [S/m] or less (also referred to as a "binder" or "host polymer"), a charge-transporting host compound (a "matrix material", or a "light-emitting host compound"). ", or simply "host") and a light-emitting dopant (also referred to as "luminescent dopant" or simply "dopant"), and the hole mobility and electron mobility of the light-emitting layer Absolute of log([electron mobility]/[hole mobility]) where the absolute value of the difference of the common logarithms is the common logarithm of the value of the ratio of [electron mobility] to [hole mobility] value is 4.5 or less.
　本発明の実施態様としては、前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が３．５以下であることが、ポリマーのブロック機能を最大限に活用し、再結合確率及び駆動寿命を向上し、大気下製造下の影響を抑制する観点から好ましい。より好ましくは２．５以下である。
　なお、前記発光層の総質量を１００とした場合の前記ポリマーの質量比率が５～８０％の範囲内であることが、正孔及び電子の移動度を制御する観点から好ましい。 As an embodiment of the present invention, the absolute value of the difference between the common logarithm of the hole mobility and the electron mobility of the light-emitting layer is 3.5 or less. It is preferable from the viewpoint of improving the bonding probability and driving life and suppressing the influence of manufacturing in the atmosphere. More preferably, it is 2.5 or less.
From the viewpoint of controlling the mobility of holes and electrons, it is preferable that the mass ratio of the polymer is in the range of 5 to 80% when the total mass of the light-emitting layer is 100.
　本発明では、前記発光層の電極側界面にポリマーが局在されることが好ましい。
　また、発光層に隣接して電極を設けるが、その他の正孔注入層（陽極バッファー層）、正孔輸送層、正孔阻止層（正孔障壁層）、電子注入層（陰極バッファー層）、電子輸送層及び電子阻止層（電子障壁層）等が適宜有機ＥＬ素子を構成する層として設けられてもよい。
　これらの各層は、本発明の規定を満たす限り、公知の材料及び方法で形成することができる。 In the present invention, it is preferable that the polymer is localized at the electrode-side interface of the light-emitting layer.
In addition, although an electrode is provided adjacent to the light emitting layer, other hole injection layer (anode buffer layer), hole transport layer, hole blocking layer (hole barrier layer), electron injection layer (cathode buffer layer), An electron-transporting layer, an electron-blocking layer (electron-blocking layer), and the like may be appropriately provided as layers constituting the organic EL element.
Each of these layers can be formed with known materials and methods as long as they satisfy the provisions of the present invention.
　前記発光層が、電荷注入層に直接隣接する又は電極に直接隣接することが、電荷キャリアの移動度を制御する点で好ましい。なお、「直接隣接する」とは、発光層と電荷注入層又は電極の間に何らの機能層も存在せず、直接的に接して存在することをいう。 From the viewpoint of controlling the mobility of charge carriers, it is preferable that the light emitting layer is directly adjacent to the charge injection layer or directly adjacent to the electrode. The term "directly adjacent" means that there is no functional layer between the light-emitting layer and the charge injection layer or electrode, and the layers are in direct contact with each other.
　本発明でいう上記「発光層の電極側界面」とは、発光層に対して電極側にある、陽極又は陰極を含めたいずれかの機能層に接する発光層の界面をいう。
　例えば発光層の陽極側に隣接して「正孔輸送層」がある場合は、「発光層の正孔輸送側の界面」を指す。 In the present invention, the "electrode-side interface of the light-emitting layer" refers to the interface of the light-emitting layer that is in contact with any functional layer including the anode or the cathode, which is on the electrode side of the light-emitting layer.
For example, when there is a "hole-transporting layer" adjacent to the anode side of the light-emitting layer, it means "the interface on the hole-transporting side of the light-emitting layer".
　（発光層材料）
　発光層に使われるポリマー材料は、インク物性や塗膜性に合わせて大小さまざまな分子量分布のものを使用できる。
　また、発光層を構成する発光層材料は、高分子でも低分子でもよい。
　低分子材料を塗布型によって形成すると、高分子鎖間にドーパント分子が分散して発光効率が高くなり好ましい。 (Light emitting layer material)
Polymer materials used in the light-emitting layer can have various molecular weight distributions, depending on the physical properties of the ink and coating properties.
Moreover, the material for the light-emitting layer that constitutes the light-emitting layer may be either a polymer or a low-molecular weight material.
When the low-molecular-weight material is formed by coating, the dopant molecules are dispersed between the polymer chains to increase the luminous efficiency, which is preferable.
　分子量は３０００以下の化合物であるものとしてもよい。分子量３０００以下の化合物とすることで、溶媒に対する溶解性が向上する。なお、好ましくは、分子量５００以上である。 A compound with a molecular weight of 3000 or less may be used. By using a compound having a molecular weight of 3000 or less, the solubility in a solvent is improved. In addition, preferably, the molecular weight is 500 or more.
　また、発光層材料として使用される発光性ドーパント及びホスト化合物の分子量は特に限定されるものではないが、本発明に係る発光層は、ジベンゾフラン環、ジベンゾチオフェン環又はカルバゾール環を有し、かつアルキル基、アルケニル基、アルキニル基又はアリールアルキル基を有しない化合物を含有することが好ましい。 Further, the molecular weights of the light-emitting dopant and the host compound used as light-emitting layer materials are not particularly limited. It is preferred to contain compounds that do not contain any radicals, alkenyl groups, alkynyl groups or arylalkyl groups.
　（層厚）
　発光層の厚さは特に限定されるものではないが、再結合領域と電子輸送層との距離の観点から、５０ｎｍ以上であることが好ましく、７０ｎｍ以上であることがより好ましい。
　また、駆動電圧の観点から、１５０ｎｍ以下であることが好ましい。 (layer thickness)
Although the thickness of the light-emitting layer is not particularly limited, it is preferably 50 nm or more, more preferably 70 nm or more, from the viewpoint of the distance between the recombination region and the electron transport layer.
Moreover, from the viewpoint of driving voltage, it is preferably 150 nm or less.
　（形成方法）
　発光層の形成方法は特に制限はないが、ポリマーを含むことから湿式法等により形成することが好ましい。
　この場合、真空蒸着等に比べ、有機ＥＬ素子の製造コストを低減することができる。 (Formation method)
The method for forming the light-emitting layer is not particularly limited, but it is preferably formed by a wet method or the like because it contains a polymer.
In this case, the manufacturing cost of the organic EL element can be reduced as compared with vacuum deposition or the like.
　湿式法としては、例えばスピンコート法、キャスト法、インクジェット印刷法、印刷法、ダイコート法、ブレードコート法、ロールコート法、ディスペンサー法、スプレーコート法、カーテンコート法、ＬＢ法（ラングミュア－ブロジェット法）等を用いることができる。
　中でも、均質な薄膜が得られやすく、かつ、高生産性の点から、ダイコート法、ロールコート法、ディスペンサー法、及びインクジェット印刷法等のロールｔｏロール方式に適用可能な方法が好ましい。
　インクジェット印刷法については後述する。 Wet methods include, for example, a spin coating method, a casting method, an inkjet printing method, a printing method, a die coating method, a blade coating method, a roll coating method, a dispenser method, a spray coating method, a curtain coating method, an LB method (Langmuir-Blodgett method, ) etc. can be used.
Among them, a method applicable to a roll-to-roll system such as a die coating method, a roll coating method, a dispenser method, and an inkjet printing method is preferable because a homogeneous thin film can be easily obtained and high productivity can be obtained.
The inkjet printing method will be described later.
　湿式法において、発光層材料を溶解又は分散する液媒体としては、例えばイソプロパノール、テトラフルオロプロパノール等のアルコール類、メチルエチルケトン、シクロヘキサノン等のケトン類、酢酸エチル等の脂肪酸エステル類、クロロホルム、ジクロロベンゼン等のハロゲン化炭化水素類、トルエン、キシレン、メシチレン、シクロヘキシルベンゼン等の芳香族炭化水素類、シクロヘキサン、デカリン、ドデカン等の脂肪族炭化水素類、ジメチルホルムアミド（ＤＭＦ）及びジメチルスルホキシド（ＤＭＳＯ）等の有機溶媒を用いることができる。 In the wet method, the liquid medium for dissolving or dispersing the light emitting layer material includes, for example, alcohols such as isopropanol and tetrafluoropropanol, ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, chloroform, dichlorobenzene and the like. Halogenated hydrocarbons, aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, organic solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) can be used.
　また、発光層材料を液媒体中に分散させる場合には、例えば超音波、高剪断力分散やメディア分散等の分散方法により分散させることができる。 Further, when dispersing the light-emitting layer material in a liquid medium, it can be dispersed by a dispersion method such as ultrasonic waves, high-shear force dispersion, or media dispersion.
　また、発光層の形成方法としては、大気、不活性ガス下どちらの形成でも可能である。
　大気下の場合は、発光層表面の吸着活性ガスの吸着が飽和し、大気劣化度が一様にそろうため色度のばらつきや発光ムラが抑えられる利点もある。 As for the method of forming the light-emitting layer, it can be formed either in the atmosphere or under an inert gas.
In the case of the atmosphere, the adsorption of the adsorbed active gas on the surface of the light-emitting layer is saturated, and the degree of atmospheric degradation is evened out, so there is also the advantage of suppressing variations in chromaticity and uneven light emission.
　〔１．１．１．１〕ポリマー
　本発明に係る発光層が含有するポリマーは、導電率が１［Ｓ／ｍ］以下であることを特徴とする。
　なお、「導電率（「電気伝導率」又は「電気伝導度」ともいう。）」とは、どの程度電気を通しやすいかを表す指標となる値をいい、電気抵抗率の逆数をＳＩ系単位であるＳ／ｍ（ジーメンス毎メートル）で表すことにする。 [1.1.1.1] Polymer The polymer contained in the light-emitting layer according to the invention is characterized by having an electrical conductivity of 1 [S/m] or less.
In addition, "conductivity (also referred to as "electrical conductivity" or "electrical conductivity")" refers to a value that is an index representing how easily electricity can pass, and the reciprocal of electrical resistivity is the SI unit is expressed as S/m (Siemens per meter).
　電気抵抗率は、ニ重リング電極を用いた定電圧印加・漏洩電流測定法によりＪＩＳ－Ｋ－６９１１に準拠した条件で得られた値を用いる。 For the electrical resistivity, use the value obtained under the conditions compliant with JIS-K-6911 by applying a constant voltage and measuring the leakage current using a double ring electrode.
　導電率が１Ｓ／ｍ以下であることにより、注入される電子及び正孔すなわち電荷キャリアの移動を制御しやすい。
　導電率が１０－８Ｓ／ｍ以下である比較的低い導電性又は絶縁性であることがより好ましい。
　一方、導電率が１Ｓ／ｍを超えると、ホスト化合物やドーパントに電荷が移動するよりもポリマーを伝うほうが律速となり、再結合確率が低下する。 A conductivity of 1 S/m or less facilitates controlling the movement of injected electrons and holes, ie charge carriers.
More preferably, it has relatively low conductivity or insulation, with a conductivity of 10 −8 S/m or less.
On the other hand, when the electrical conductivity exceeds 1 S/m, the rate of charge transfer through the polymer becomes more rate-determining than the charge transfer to the host compound or dopant, and the recombination probability decreases.
　前記ポリマーが、ベンゼン環を含むポリマーであることが、高膜密度化とキャリア輸送材料やドーパント分散化の効果を得やすい観点で好ましい。 It is preferable that the polymer is a polymer containing a benzene ring, from the viewpoint of easily obtaining the effects of increasing the film density and dispersing the carrier transport material and the dopant.
　前記ベンゼン環を含むポリマーが、非共役ポリマーであることが、キャリアブロックの観点で好ましく、特に隣接層に電荷ブロック層や逆電荷の輸送層を持たない場合、すなわち電極や注入層に直接発光層を設置する場合に、発光内に電荷を留めて再結合確率を上げる観点で好ましい。 It is preferable that the polymer containing the benzene ring is a non-conjugated polymer from the viewpoint of carrier blocking. is preferable from the viewpoint of increasing the recombination probability by retaining the charge in the emitted light.
　前記非共役ポリマーが、ベンゼン環を側鎖として含むことが、上記高密度化及びキャリア輸送材料やドーパント分散化の効果の観点で好ましい。 It is preferable that the non-conjugated polymer contains a benzene ring as a side chain from the viewpoint of the effect of increasing the density and dispersing the carrier transport material and the dopant.
　前記非共役ポリマーが、ポリスチレンであることが、界面再結合抑制の観点で好ましい。 From the viewpoint of interfacial recombination suppression, it is preferable that the non-conjugated polymer is polystyrene.
　前記非共役ポリマーが、ポリスチレン誘導体であることが、界面再結合抑制の観点でより好ましい。
　本発明の効果はベンゼン環を含むポリマーで顕著であり、特に、ポリスチレンのように側鎖にベンゼン環を含むポリマーの場合、π共役を多く含む発光層材料と相互作用して乾燥時に発光層材料分子を内包しやすく、相分離構造を形成してトラップ抑制効果及びキャリアブロック効果を得やすい。 From the viewpoint of suppressing interfacial recombination, the non-conjugated polymer is more preferably a polystyrene derivative.
The effect of the present invention is remarkable for polymers containing benzene rings. In particular, in the case of polymers containing benzene rings in side chains such as polystyrene, the light-emitting layer material interacts with the light-emitting layer material containing many π It easily encapsulates molecules and forms a phase-separated structure to easily obtain a trap suppressing effect and a carrier blocking effect.
　前記ポリスチレン誘導体が、ポリビニルフェノールであることが、両電極側界面再結合抑制の観点で好ましい。
　ポリビニルフェノール（ＰＶＰｈ）のように側鎖に極性基付加ベンゼン環を含むことで、高分子間の水素結合を形成し、乾燥時の加熱により相分離構造の形成が促進される。
　膜がπ－π相互作用及び水素結合により高密度に形成されるため、同様の相互作用ネットワークを介するホスト及びドーパントで形成されたキャリア輸送部も高密度化する。 It is preferable that the polystyrene derivative is polyvinylphenol from the viewpoint of suppression of recombination at the interface between both electrodes.
By including a polar group-added benzene ring in the side chain like polyvinylphenol (PVPh), hydrogen bonds between polymers are formed, and the formation of a phase separation structure is promoted by heating during drying.
As the film is densely formed by π-π interactions and hydrogen bonding, the carrier transport sites formed by hosts and dopants through similar interaction networks are also densified.
　前記非共役ポリマーが、立体規則性の異なる成分の混合物であることが、ポリマーの界面局在量を制御し、キャリアバランスの調整ができる観点で好ましい。
　前記発光層のポリマーは、公知の材料から適宜選択して用いることができる。
　例えばポリエチレン、ポリプロピレン、ポリフッ化ビニリデン、ポリアクリロニトリル等のポリアルキレン、ポリカーボネート、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリフェニルエーテル、ポリエチレンエーテルケトン、ポリフェニレンスルフィド、ポリフェニレンスルホン、ポリスルホン、ポリエーテルスルホン、ポリアリレート、ポリスチレン、ポリビニルフェノール及びこれらのポリマーの誘導体等の芳香環含有ポリマー、フェノール樹脂及びエポキシ樹脂等の硬化樹脂等を用いることができる。
　中でも、芳香環含有ポリマーが電極結晶格子との噛み合わせや隣接層との相互作用の観点で好ましい。 It is preferable that the non-conjugated polymer is a mixture of components with different stereoregularities from the viewpoint of controlling the amount of polymer localized at the interface and adjusting the carrier balance.
The polymer of the light-emitting layer can be appropriately selected from known materials and used.
Polyalkylenes such as polyethylene, polypropylene, polyvinylidene fluoride, polyacrylonitrile, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyphenyl ether, polyethylene ether ketone, polyphenylene sulfide, polyphenylene sulfone, polysulfone, polyether sulfone, polyarylate, polystyrene, Aromatic ring-containing polymers such as polyvinylphenol and derivatives of these polymers, cured resins such as phenolic resins and epoxy resins, and the like can be used.
Among them, aromatic ring-containing polymers are preferable from the viewpoint of meshing with the electrode crystal lattice and interaction with adjacent layers.
　（芳香環含有ポリマー）
　本発明に用いられるポリマーとしては下記一般式（I）及び一般式（II）で表される構造を有する芳香環含有ポリマーであることが好ましい。
　特に、ベンゼン環を含むポリマーであることが好ましい。
　また、前記ベンゼン環を含むポリマーが、非共役ポリマーであることが好ましい。
　さらに、非共役ポリマーが、ベンゼン環を側鎖として含むポリマー、例えばポリスチレンやポリスチレン誘導体であることも好ましい。
　以下において、下記一般式（I）及び一般式（II）で表される構造を有する芳香環含有ポリマーについて詳細な説明をする。 (Aromatic ring-containing polymer)
Polymers used in the present invention are preferably aromatic ring-containing polymers having structures represented by the following general formulas (I) and (II).
In particular, polymers containing benzene rings are preferred.
Moreover, it is preferable that the polymer containing the benzene ring is a non-conjugated polymer.
Furthermore, it is also preferred that the non-conjugated polymer is a polymer containing benzene rings as side chains, such as polystyrene or polystyrene derivatives.
The aromatic ring-containing polymers having structures represented by the following general formulas (I) and (II) will be described in detail below.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
　上記一般式（I）及び一般式（II）において、Ａは、芳香環を表し、当該芳香環には芳香族炭化水素環及び芳香族複素環が含まれる。これらは、それぞれ単環であっても縮合環であっても良い。Ｌは、二価の連結基を表す。ｘ及びｙは、０又は１以上の整数を表す。ｎは、重合度を表し、１０以上、１０万以下である。 In the general formulas (I) and (II) above, A represents an aromatic ring, and the aromatic ring includes an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Each of these may be a monocyclic ring or a condensed ring. L represents a divalent linking group. x and y represent an integer of 0 or 1 or more. n represents the degree of polymerization and is 10 or more and 100,000 or less.
　Ａで表される芳香環には、前述のように、芳香族炭化水素環及び芳香族複素環が含まれる。これらは、それぞれ単環であっても縮合環であっても良い。
　導電率又は絶縁性の観点から、芳香環は、芳香族炭化水素環であることが好ましい。
　上記一般式（I）及び一般式（II）から置換基を除いた芳香環を構成する原子数は、溶解性の観点から２０以下が好ましく、１２以下がより好ましく、６以下が更に好ましい。 The aromatic ring represented by A includes an aromatic hydrocarbon ring and an aromatic heterocyclic ring, as described above. Each of these may be a monocyclic ring or a condensed ring.
From the viewpoint of conductivity or insulation, the aromatic ring is preferably an aromatic hydrocarbon ring.
From the viewpoint of solubility, the number of atoms constituting the aromatic ring of general formula (I) and general formula (II) excluding substituents is preferably 20 or less, more preferably 12 or less, and even more preferably 6 or less.
　芳香族炭化水素環としては、例えばベンゼン環、ナフタレン環、フルオレン環、アントラセン環、フェンスレン環、テトラセン環、ペンタセン環、クリセン環、ピレン環、ペリレン環、コロネン環、フルオランテン環、ジベンゾアントラセン環、ベンゾピレン環等のアセン系構造が挙げられ、好ましくはベンゼン環、ナフタレン環である。 Examples of aromatic hydrocarbon rings include benzene ring, naphthalene ring, fluorene ring, anthracene ring, phenthrene ring, tetracene ring, pentacene ring, chrysene ring, pyrene ring, perylene ring, coronene ring, fluoranthene ring, dibenzoanthracene ring, Examples include acene structures such as benzopyrene ring, preferably benzene ring and naphthalene ring.
　芳香族複素環としては、例えばピリジン環、ピリミジン環、トリアジン環、キノリン環、イソキノリン環、アクリジン環、チオフェン環、フラン環、ピロール環、ベンゾフラン環、ベンゾチオフェ環ン、インドール環、イミダゾール環、ピラゾール環、オキサゾール環、イゾオキサゾール環、チアゾール環、イソチアゾール環、トリアゾール環、オキサジアゾール環、チアジアゾール環、ジオキサゾール環、ジチアゾール環、テトラゾール環、ペンタゾール環等が挙げられる。 Examples of aromatic heterocyclic rings include pyridine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, acridine ring, thiophene ring, furan ring, pyrrole ring, benzofuran ring, benzothiophene ring, indole ring, imidazole ring and pyrazole ring. , oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, dioxazole ring, dithiazole ring, tetrazole ring, pentazole ring and the like.
　発光層材料を相互作用により相溶させる観点から、Ａで表される芳香環がベンゼン環であることが好ましく、具体的には以下の一般式（III）構造のものが挙げられる。 From the viewpoint of compatibility with the light-emitting layer material through interaction, the aromatic ring represented by A is preferably a benzene ring, and specific examples include the structure of the following general formula (III).
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
　上記一般式（III）中、Ｘ及びＹは、水素又は前記一般式（I）及び一般式（II）における繰り返し単位Ｌ又はＡとの結合部を表す。 In the above general formula (III), X and Y represent hydrogen or a bond with the repeating unit L or A in the general formula (I) and general formula (II).
　Ｒ１～Ｒ５は、水素又は置換基を示し、それぞれ独立して水素原子、重水素原子、ハロゲン原子、ヒドロキシ基、カルボキシ基、スルホ基、アルコキシカルボニル基、ハロホルミル基、ホルミル基、アシル基、アルコキシ基、メルカプト基、シアノ基、アルキル基、アルケニル基、アルキニル基、アルコキシ基、アミノ基、カルバモイル基、シリル基、ホスフィンオキシド基、イミド基、芳香族イミド環基、芳香族炭化水素環基、芳香族複素環基、非芳香族炭化水素環基、又は非芳香族複素環基を表し、更に置換基を有していても良い。 R 1 to R 5 represent hydrogen or substituents, each independently hydrogen atom, deuterium atom, halogen atom, hydroxy group, carboxy group, sulfo group, alkoxycarbonyl group, haloformyl group, formyl group, acyl group, alkoxy group, mercapto group, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, carbamoyl group, silyl group, phosphine oxide group, imide group, aromatic imide ring group, aromatic hydrocarbon ring group, It represents an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group, or a non-aromatic heterocyclic group, and may further have a substituent.
　上記一般式（I）、一般式（II）及び上記一般式（III）中、Ｒ１～Ｒ５で表されるアルキル基としては、例えばメチル基、エチル基、プロピル基、イソプロピル基、（ｔ）ブチル基、ペンチル基、ヘキシル基、オクチル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ベンジル基等を挙げることができる。 Examples of alkyl groups represented by R 1 to R 5 in general formula (I), general formula (II) and general formula (III) above include methyl group, ethyl group, propyl group, isopropyl group, (t ) butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group and the like.
　Ｒ１～Ｒ５で表されるアルケニル基としては、例えば上記アルキル基に一個以上の二重結合を有するものが挙げられ、より具体的には、ビニル基、アリル基、１－プロペニル基、イソプロペニル基、２－ブテニル基、１，３－ブタジエニル基、２－ペンテニル基、２－ヘキセニル基等が挙げられる。 Alkenyl groups represented by R 1 to R 5 include, for example, those having one or more double bonds in the above alkyl group, more specifically vinyl group, allyl group, 1-propenyl group, iso propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group and the like.
　Ｒ１～Ｒ５で表されるアルキニル基としては、例えばエチニル基、アセチレニル基、１－プロピニル基、２－プロピニル基（プロパルギル基）、１－ブチニル基、２－ブチニル基、３－ブチニル基、１－ペンチニル基、２－ペンチニル基、３－ペンチニル基、１－ヘキシニル基、２－ヘキシニル基、３－ヘキシニル基、１－ヘプチニル基、２－ヘプチニル基、５－ヘプチニル基、１－オクチニル基、３－オクチニル基、５－オクチニル基等が挙げられる。
　Ｒ１～Ｒ５で表される芳香族炭化水素環基（アリール基ともいう。）としては、例えばフェニル基、ｐ－クロロフェニル基、メシチル基、トリル基、キシリル基、ナフチル基、アントリル基、アズレニル基、アセナフテニル基、フルオレニル基、フェナントリル基、インデニル基、ピレニル基、ビフェニリル基等が挙げられる。 Examples of alkynyl groups represented by R 1 to R 5 include ethynyl group, acetylenyl group, 1-propynyl group, 2-propynyl group (propargyl group), 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-pentynyl group, 2-pentynyl group, 3-pentynyl group, 1-hexynyl group, 2-hexynyl group, 3-hexynyl group, 1-heptynyl group, 2-heptynyl group, 5-heptynyl group, 1-octynyl group, 3-octynyl group, 5-octynyl group and the like.
Examples of aromatic hydrocarbon ring groups (also referred to as aryl groups) represented by R 1 to R 5 include phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group and azulenyl. group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like.
　Ｒ１～Ｒ５で表される芳香族複素環基としては、例えばピリジル基、ピリミジニル基、フリル基、ピロリル基、イミダゾリル基、ベンゾイミダゾリル基、ピラゾリル基、ピラジニル基、トリアゾリル基（例えば１，２，４－トリアゾール－１－イル基、１，２，３－トリアゾール－１－イル基等）、オキサゾリル基、ベンゾオキサゾリル基、チアゾリル基、イソオキサゾリル基、イソチアゾリル基、フラザニル基、チエニル基、キノリル基、ベンゾフリル基、ジベンゾフリル基、ベンゾチエニル基、ジベンゾチエニル基、インドリル基、カルバゾリル基、カルボリニル基、ジアザカルバゾリル基（前記カルボリニル基のカルボリン環を構成する炭素原子の一つが窒素原子で置き換わったものを示す。）、キノキサリニル基、ピリダジニル基、トリアジニル基、キナゾリニル基、フタラジニル基等が挙げられる。 Examples of aromatic heterocyclic groups represented by R 1 to R 5 include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group and triazolyl group (e.g., 1, 2, 4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group , benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced with a nitrogen atom). ), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, and the like.
　Ｒ１～Ｒ５で表される非芳香族炭化水素環基としては、例えばシクロアルキル基（例えばシクロペンチル基、シクロヘキシル基等）、シクロアルコキシ基（例えばシクロペンチルオキシ基、シクロヘキシルオキシ基等）、シクロアルキルチオ基（例えばシクロペンチルチオ基、シクロヘキシルチオ基等）、テトラヒドロナフタレン環、９，１０－ジヒドロアントラセン環、ビフェニレン環等から導出される一価の基等が挙げられる。 Examples of non-aromatic hydrocarbon ring groups represented by R 1 to R 5 include cycloalkyl groups (eg, cyclopentyl group, cyclohexyl group, etc.), cycloalkoxy groups (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), cycloalkylthio monovalent groups derived from groups (eg, cyclopentylthio group, cyclohexylthio group, etc.), tetrahydronaphthalene ring, 9,10-dihydroanthracene ring, biphenylene ring, etc.;
　Ｒ１～Ｒ５で表される非芳香族炭化水素環基としては、例えばエポキシ環、アジリジン環、チイラン環、オキセタン環、アゼチジン環、チエタン環、テトラヒドロフラン環、ジオキソラン環、ピロリジン環、ピラゾリジン環、イミダゾリジン環、オキサゾリジン環、テトラヒドロチオフェン環、スルホラン環、チアゾリジン環、ε－カプロラクトン環、ε－カプロラクタム環、ピペリジン環、ヘキサヒドロピリダジン環、ヘキサヒドロピリミジン環、ピペラジン環、モルホリン環、テトラヒドロピラン環、１，３－ジオキサン環、１，４－ジオキサン環、トリオキサン環、テトラヒドロチオピラン環、チオモルホリン環、チオモルホリン－１，１－ジオキシド環、ピラノース環、ジアザビシクロ［２，２，２］－オクタン環、フェノキサジン環、フェノチアジン環、オキサントレン環、チオキサンテン環、フェノキサチイン環等から導出される一価の基等が挙げられる。 Examples of non-aromatic hydrocarbon ring groups represented by R 1 to R 5 include epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1,1-dioxide ring, pyranose ring, diazabicyclo[2,2,2]-octane ring , phenoxazine ring, phenothiazine ring, oxantrene ring, thioxanthene ring, phenoxathiin ring and the like.
　Ｒ１～Ｒ５で表されるアルコキシ基としては、例えばメトキシ基、エトキシ基、プロポキシ基、イソプロポキシ基、ブトキシ基、ペンチルオキシ基、ヘキシルオキシ基、２－エチルヘキシルオキシ基、オクチルオキシ基、ノニルオキシ基、デシルオキシ基、ウンデシルオキシ基、ドデシルオキシ基、トリデシルオキシ基、テトラデシルオキシ基、ペンタデシルオキシ基、ヘキサデシルオキシ基、ヘプタデシルオキシ基、オクタデシルオキシ基等が挙げられる。 Examples of alkoxy groups represented by R 1 to R 5 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, 2-ethylhexyloxy, octyloxy and nonyloxy. group, decyloxy group, undecyloxy group, dodecyloxy group, tridecyloxy group, tetradecyloxy group, pentadecyloxy group, hexadecyloxy group, heptadecyloxy group, octadecyloxy group and the like.
　Ｒ１～Ｒ５で表されるアシル基としては、例えばアセチル基、エチルカルボニル基、プロピルカルボニル基、ペンチルカルボニル基、シクロヘキシルカルボニル基、オクチルカルボニル基、２－エチルヘキシルカルボニル基、ドデシルカルボニル基、フェニルカルボニル基、ナフチルカルボニル基、ピリジルカルボニル基等が挙げられる。 Acyl groups represented by R 1 to R 5 include, for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group and phenylcarbonyl group. group, naphthylcarbonyl group, pyridylcarbonyl group, and the like.
　Ｒ１～Ｒ５で表されるアミノ基としては、例えばアミノ基、エチルアミノ基、ジメチルアミノ基、ブチルアミノ基、シクロペンチルアミノ基、２－エチルヘキシルアミノ基、ドデシルアミノ基、アニリノ基、ナフチルアミノ基、２－ピリジルアミノ基等が挙げられる。 Examples of amino groups represented by R 1 to R 5 include amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group and naphthylamino group. , 2-pyridylamino group and the like.
　Ｒ１～Ｒ５で表されるシリル基としては、例えばトリメチルシリル基、トリイソプロピルシリル基、トリフェニルシリル基、フェニルジエチルシリル基等が挙げられる。 Silyl groups represented by R 1 to R 5 include, for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group and phenyldiethylsilyl group.
　Ｒ１～Ｒ５で表されるホスフィンオキシド基としては、例えばジフェニルホスフィンオキシド基、ジトリルホスフィンオキシド基、ジメチルホスフィンオキシド基、ジナフチルホスフィンオキシド基、９，１０－ジヒドロ－９－オキサ－１０－ホスファフェナントレン－１０－オキサイド基等を挙げることができる。 Phosphine oxide groups represented by R 1 to R 5 include, for example, diphenylphosphine oxide group, ditolylphosphine oxide group, dimethylphosphine oxide group, dinaphthylphosphine oxide group, 9,10-dihydro-9-oxa-10- A phosphaphenanthrene-10-oxide group and the like can be mentioned.
　Ｒ１～Ｒ５で表される基が更に有していても良い置換基としては、例えば各々独立に、アルキル基（例えばメチル基、エチル基、プロピル基、イソプロピル基、（ｔ）ブチル基、ペンチル基、ヘキシル基、オクチル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ベンジル基等）、シクロアルキル基（例えばシクロペンチル基、シクロヘキシル基等）、アルケニル基（例えばビニル基、アリル基等）、アルキニル基（例えばプロパルギル基等）、芳香族炭化水素基（アリール基ともいい、例えばフェニル基、ｐ－クロロフェニル基、メシチル基、トリル基、キシリル基、ナフチル基、アントリル基、アズレニル基、アセナフテニル基、フルオレニル基、フェナントリル基、インデニル基、ピレニル基、ビフェニリル基等）、複素環基（例えばエポキシ環、アジリジン環、チイラン環、オキセタン環、アゼチジン環、チエタン環、テトラヒドロフラン環、ジオキソラン環、ピロリジン環、ピラゾリジン環、イミダゾリジン環、オキサゾリジン環、テトラヒドロチオフェン環、スルホラン環、チアゾリジン環、ε－カプロラクトン環、ε－カプロラクタム環、ピペリジン環、ヘキサヒドロピリダジン環、ヘキサヒドロピリミジン環、ピペラジン環、モルホリン環、テトラヒドロピラン環、１，３－ジオキサン環、１，４－ジオキサン環、トリオキサン環、テトラヒドロチオピラン環、チオモルホリン環、チオモルホリン１，１－ジオキシド環、ピラノース環、ジアザビシクロ［２，２，２］－オクタン環等）、芳香族複素環基（ピリジル基、ピリミジニル基、フリル基、ピロリル基、イミダゾリル基、ベンゾイミダゾリル基、ピラゾリル基、ピラジニル基、トリアゾリル基（例えば１，２，４－トリアゾール－１－イル基、１，２，３－トリアゾール－１－イル基等）、オキサゾリル基、ベンゾオキサゾリル基、チアゾリル基、イソオキサゾリル基、イソチアゾリル基、フラザニル基、チエニル基、キノリル基、ベンゾフリル基、ジベンゾフリル基、ベンゾチエニル基、ジベンゾチエニル基、インドリル基、カルバゾリル基、カルボリニル基、ジアザカルバゾリル基（前記カルボリニル基のカルボリン環を構成する炭素原子の一つが窒素原子で置き換わったものを示す。）、キノキサリニル基、ピリダジニル基、トリアジニル基、キナゾリニル基、フタラジニル基等）、ハロゲン原子（例えば塩素原子、臭素原子、ヨウ素原子、フッ素原子等）、アルコキシ基（例えばメトキシ基、エトキシ基、プロピルオキシ基、ペンチルオキシ基、ヘキシルオキシ基、オクチルオキシ基、ドデシルオキシ基等）、シクロアルコキシ基（例えばシクロペンチルオキシ基、シクロヘキシルオキシ基等）、アリールオキシ基（例えばフェノキシ基、ナフチルオキシ基等）、アルキルチオ基（例えばメチルチオ基、エチルチオ基、プロピルチオ基、ペンチルチオ基、ヘキシルチオ基、オクチルチオ基、ドデシルチオ基等）、シクロアルキルチオ基（例えばシクロペンチルチオ基、シクロヘキシルチオ基等）、アリールチオ基（例えばフェニルチオ基、ナフチルチオ基等）、アルコキシカルボニル基（例えばメチルオキシカルボニル基、エチルオキシカルボニル基、ブチルオキシカルボニル基、オクチルオキシカルボニル基、ドデシルオキシカルボニル基等）、アリールオキシカルボニル基（例えばフェニルオキシカルボニル基、ナフチルオキシカルボニル基等）、スルファモイル基（例えばアミノスルホニル基、メチルアミノスルホニル基、ジメチルアミノスルホニル基、ブチルアミノスルホニル基、ヘキシルアミノスルホニル基、シクロヘキシルアミノスルホニル基、オクチルアミノスルホニル基、ドデシルアミノスルホニル基、フェニルアミノスルホニル基、ナフチルアミノスルホニル基、２－ピリジルアミノスルホニル基等）、ウレイド基（例えばメチルウレイド基、エチルウレイド基、ペンチルウレイド基、シクロヘキシルウレイド基、オクチルウレイド基、ドデシルウレイド基、フェニルウレイド基、ナフチルウレイド基、２－ピリジルアミノウレイド基等）、アシル基（例えばアセチル基、エチルカルボニル基、プロピルカルボニル基、ペンチルカルボニル基、シクロヘキシルカルボニル基、オクチルカルボニル基、２－エチルヘキシルカルボニル基、ドデシルカルボニル基、フェニルカルボニル基、ナフチルカルボニル基、ピリジルカルボニル基等）、アシルオキシ基（例えばアセチルオキシ基、エチルカルボニルオキシ基、ブチルカルボニルオキシ基、オクチルカルボニルオキシ基、ドデシルカルボニルオキシ基、フェニルカルボニルオキシ基等）、アミド基（例えばメチルカルボニルアミノ基、エチルカルボニルアミノ基、ジメチルカルボニルアミノ基、プロピルカルボニルアミノ基、ペンチルカルボニルアミノ基、シクロヘキシルカルボニルアミノ基、２－エチルヘキシルカルボニルアミノ基、オクチルカルボニルアミノ基、ドデシルカルボニルアミノ基、フェニルカルボニルアミノ基、ナフチルカルボニルアミノ基等）、カルバモイル基（例えばアミノカルボニル基、メチルアミノカルボニル基、ジメチルアミノカルボニル基、プロピルアミノカルボニル基、ペンチルアミノカルボニル基、シクロヘキシルアミノカルボニル基、オクチルアミノカルボニル基、２－エチルヘキシルアミノカルボニル基、ドデシルアミノカルボニル基、フェニルアミノカルボニル基、ナフチルアミノカルボニル基、２－ピリジルアミノカルボニル基等）、スルフィニル基（例えばメチルスルフィニル基、エチルスルフィニル基、ブチルスルフィニル基、シクロヘキシルスルフィニル基、２－エチルヘキシルスルフィニル基、ドデシルスルフィニル基、フェニルスルフィニル基、ナフチルスルフィニル基、２－ピリジルスルフィニル基等）、アルキルスルホニル基又はアリールスルホニル基（例えばメチルスルホニル基、エチルスルホニル基、ブチルスルホニル基、シクロヘキシルスルホニル基、２－エチルヘキシルスルホニル基、ドデシルスルホニル基、フェニルスルホニル基、ナフチルスルホニル基、２－ピリジルスルホニル基等）、アミノ基（例えばアミノ基、エチルアミノ基、ジメチルアミノ基、ブチルアミノ基、シクロペンチルアミノ基、２－エチルヘキシルアミノ基、ドデシルアミノ基、アニリノ基、ジアリールアミノ基（例えばジフェニルアミノ基、ジナフチルアミノ基、フェニルナフチルアミノ基等）、ナフチルアミノ基、２－ピリジルアミノ基等）、ニトロ基、シアノ基、ヒドロキシ基、メルカプト基、アルキルシリル基又はアリールシリル基（例えばトリメチルシリル基、トリエチルシリル基、（ｔ）ブチルジメチルシリル基、トリイソプロピルシリル基、（ｔ）ブチルジフェニルシリル基、トリフェニルシリル基、トリナフチルシリル基、２－ピリジルシリル基等）、アルキルホスフィノ基又はアリールホスフィノ基（ジメチルホスフィノ基、ジエチルホスフィノ基、ジシクロヘキシルホスフィノ基、メチルフェニルホスフィノ基、ジフェニルホスフィノ基、ジナフチルホスフィノ基、ジ（２－ピリジル）ホスフィノ基）、アルキルホスホリル基又はアリールホスホリル基（ジメチルホスホリル基、ジエチルホスホリル基、ジシクロヘキシルホスホリル基、メチルフェニルホスホリル基、ジフェニルホスホリル基、ジナフチルホスホリル基、ジ（２－ピリジル）ホスホリル基）、アルキルチオホスホリル基又はアリールチオホスホリル基（ジメチルチオホスホリル基、ジエチルチオホスホリル基、ジシクロヘキシルチオホスホリル基、メチルフェニルチオホスホリル基、ジフェニルチオホスホリル基、ジナフチルチオホスホリル基、ジ（２－ピリジル）チオホスホリル基）から選ばれるいずれかの基を表す。
　なお、これらの置換基は更に上記の置換基によって置換されていても良いし、また、それらが互いに縮合して更に環を形成していても良い。 Substituents that the groups represented by R 1 to R 5 may further have include, for example, each independently alkyl group (eg, methyl group, ethyl group, propyl group, isopropyl group, (t) butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group, etc.), cycloalkyl group (e.g., cyclopentyl group, cyclohexyl group, etc.), alkenyl group (e.g., vinyl group, allyl group, etc.) , an alkynyl group (e.g., propargyl group, etc.), an aromatic hydrocarbon group (also called an aryl group, such as a phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group , fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), heterocyclic groups (e.g., epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydro pyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine 1,1-dioxide ring, pyranose ring, diazabicyclo[2,2,2]- octane ring etc.), aromatic heterocyclic groups (pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (e.g. 1,2,4-triazol-1-yl 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group , a benzothienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced with a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), halogen atoms (e.g., chlorine atom , bromine atom, iodine atom, fluorine atom, etc.), alkoxy groups (e.g., methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy groups (e.g., cyclopentyl oxy group, cyclohexyloxy group, etc.), aryloxy group (e.g., phenoxy group, naphthyloxy group, etc.), alkylthio group (e.g., methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (e.g., cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (e.g., phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (e.g., methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group) group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (e.g., phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (e.g., aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), ureido group (e.g., methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), acyl group (e.g., acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group) , cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (e.g., acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group , an octylcarbonyloxy group, a dodecylcarbonyloxy group, a phenylcarbonyloxy group, etc.), an amide group (e.g., a methylcarbonylamino group, an ethylcarbonylamino group, a dimethylcarbonylamino group, a propylcarbonylamino group, a pentylcarbonylamino group, a cyclohexane xylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (e.g. aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc. ), sulfinyl group (e.g., methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group or arylsulfonyl group (e.g. methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino groups (e.g. amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, diarylamino group (e.g. diphenylamino group, dinaphthylamino group, phenyl naphthylamino group, etc.), naphthylamino group, 2-pyridylamino group, etc.), nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group or arylsilyl group (e.g., trimethylsilyl group, triethylsilyl group, (t) butyldimethyl silyl group, triisopropylsilyl group, (t) butyldiphenylsilyl group, triphenylsilyl group, trinaphthylsilyl group, 2-pyridylsilyl group, etc.), alkylphosphino group or arylphosphino group (dimethylphosphino group, diethyl phosphino group, dicyclohexylphosphino group, methylphenylphosphino group, diphenylphosphino group, dinaphthylphosphino group, di(2-pyridyl)phosphino group), alkylphosphoryl group or arylphosphoryl group (dimethylphosphoryl group, diethylphosphoryl radical, dicyclohexyl phosphoryl group, methylphenylphosphoryl group, diphenylphosphoryl group, dinaphthylphosphoryl group, di(2-pyridyl)phosphoryl group), alkylthiophosphoryl group or arylthiophosphoryl group (dimethylthiophosphoryl group, diethylthiophosphoryl group, dicyclohexylthiophosphoryl group , methylphenylthiophosphoryl group, diphenylthiophosphoryl group, dinaphthylthiophosphoryl group, di(2-pyridyl)thiophosphoryl group).
These substituents may be further substituted with the above substituents, or they may be condensed with each other to form a ring.
　前記一般式（I）及び一般式（II）における、Ｌは、二価の連結基を表し、アルキレン基、アルケニレン基、カルボニル基、エーテル基、イミノ基、イミド基、アミド基、ｏ－フェニレン基、ｍ－フェニレン基、ｐ－フェニレン基、スルホニル基、スルフィド基、チオエステル基、シリル基、ホスフィンオキシド基、又は二価の芳香族複素環基を表し、更に置換基を有していても良い。 In the general formula (I) and general formula (II), L represents a divalent linking group, an alkylene group, an alkenylene group, a carbonyl group, an ether group, an imino group, an imide group, an amide group, an o-phenylene group. , m-phenylene group, p-phenylene group, sulfonyl group, sulfide group, thioester group, silyl group, phosphine oxide group, or divalent aromatic heterocyclic group, which may further have a substituent.
　前記一般式（I）及び一般式（II）において、Ｌで表されるアルキレン基としては、例えばメチレン基、エチレン基、トリメチレン基、プロピレン基、ブチレン基、ブタン－１，２－ジイル基、ヘキシレン基等が挙げられる。 In the general formulas (I) and (II), the alkylene group represented by L includes, for example, methylene group, ethylene group, trimethylene group, propylene group, butylene group, butane-1,2-diyl group, hexylene and the like.
　また、Ｌで表されるアルケニレン基としては、例えばビニレン基、プロペニレン基、ブテニレン基、ペンテニレン基、１－メチルビニレン基、１－メチルプロペニレン基、２－メチルプロペニレン基、１－メチルペンテニレン基、３－メチルペンテニレン基、１－エチルビニレン基、１－エチルプロペニレン基、１－エチルブテニレン基、３－エチルブテニレン基等が挙げられる。 The alkenylene group represented by L includes, for example, vinylene group, propenylene group, butenylene group, pentenylene group, 1-methylvinylene group, 1-methylpropenylene group, 2-methylpropenylene group, 1-methylpentenylene group, rene group, 3-methylpentenylene group, 1-ethylvinylene group, 1-ethylpropenylene group, 1-ethylbutenylene group, 3-ethylbutenylene group and the like.
　また、Ｌで表されるアミド基としては、例えばメチルカルボニルアミノ基、エチルカルボニルアミノ基、ジメチルカルボニルアミノ基、プロピルカルボニルアミノ基、ペンチルカルボニルアミノ基、シクロヘキシルカルボニルアミノ基、２－エチルヘキシルカルボニルアミノ基、オクチルカルボニルアミノ基、ドデシルカルボニルアミノ基、フェニルカルボニルアミノ基、ナフチルカルボニルアミノ基等が挙げられる。 Examples of the amide group represented by L include a methylcarbonylamino group, an ethylcarbonylamino group, a dimethylcarbonylamino group, a propylcarbonylamino group, a pentylcarbonylamino group, a cyclohexylcarbonylamino group, a 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group and the like.
　また、Ｌで表される二価の芳香族複素環基としては、例えば上記一般式（I）、一般式（II）及び上記一般式（III）中Ｒ１～Ｒ５で表される芳香族複素環基として挙げられたものから導出される二価の基が挙げられる。 Further, the divalent aromatic heterocyclic group represented by L includes , for example, aromatic Divalent groups derived from those mentioned as heterocyclic groups are included.
　式中、ｘ、ｙは、０又は１以上の整数を表す。
　ｎは、重合度を表し、１０以上、１０万以下である。
　これらの繰り返し構造は、例えばＡ－Ｌ－Ａ－Ｌの繰り返しのように逐次的に重合されたものであっても良いし、Ａ－Ａ－Ｌ－Ｌ、Ａ－Ｌ－Ｌのようなブロック重合されたものであっても良い。 In the formula, x and y represent 0 or an integer of 1 or more.
n represents the degree of polymerization and is 10 or more and 100,000 or less.
These repeating structures may be sequentially polymerized, for example, ALA repeats, or blocks such as ALALL, ALL It may be polymerized.
　また、ｘ及びｙの両方又はいずれか一方が２以上の場合、２以上のＡ、Ｌ及びＲ１～Ｒ５は互いに同じであっても異なっていても良い。 When both or either one of x and y is 2 or more, 2 or more of A, L and R 1 to R 5 may be the same or different.
　本発明において使用できるポリマー具体例としては、下記の構造をもつポリマーが挙げられる。
　下記実施例において、下記構造式（１）～（４）で表されるポリマーを用いた素子は、比較例として記載されているが、これは、発光層の正孔移動度と電子移動度の常用対数値の差の絶対値が本発明における数値規定を満たしていないためであり、数値規定を満たしている場合には、本発明に使用することができる。
　ただし、構造式（５）については、後述する比較例として挙げてある。
　なお、下記構造式において、ｎ、ｘ及びｙは整数であり、重合度ｎは、１０～１００の範囲内であり、共重合比は、ｘ：ｙ＝１：９９～９９：１の範囲内であることが好ましい。 Specific examples of polymers that can be used in the present invention include polymers having the structures shown below.
In the following examples, devices using polymers represented by the following structural formulas (1) to (4) are described as comparative examples. This is because the absolute value of the difference between the common logarithms does not satisfy the numerical specification in the present invention. If the numerical specification is satisfied, it can be used in the present invention.
However, structural formula (5) is given as a comparative example to be described later.
In the following structural formula, n, x and y are integers, the degree of polymerization n is within the range of 10 to 100, and the copolymerization ratio is x:y = 1:99 to 99:1. is preferably
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000006
　ポリマーの重量平均分子量は、結晶化や低分子成分の拡散影響を抑える観点で分子量１０００以上が好ましく、重合不純物の残留の観点から分子量３００万以下のものが好ましい。より好ましくは、５万以上１００万以下である。 The weight-average molecular weight of the polymer is preferably 1,000 or more from the viewpoint of suppressing the effects of crystallization and diffusion of low-molecular-weight components, and preferably has a molecular weight of 3,000,000 or less from the viewpoint of residual polymerization impurities. More preferably, it is 50,000 or more and 1,000,000 or less.
　ここでいう重量平均分子量とは、溶媒としてジメチルホルムアミドを用いたゲルパーミエーションクロマトグラフィー（ＧＰＣ）で測定し、ポリスチレンで換算した重量平均分子量をさす。ジメチルホルムアミドで測定できない場合については、テトラヒドロフランを用い、さらに測定できない場合は、ヘキサフルオロイソプロパノールを用い、ヘキサフルオロイソプロパノールでも測定できない場合は、２－クロロナフタレンを用いて測定を行う。 The weight average molecular weight here refers to the weight average molecular weight measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent and converted to polystyrene. If it cannot be measured with dimethylformamide, use tetrahydrofuran. If it cannot be measured, use hexafluoroisopropanol. If it cannot be measured with hexafluoroisopropanol, use 2-chloronaphthalene.
　（ポリマーの最適条件）
　ポリマー、ホスト化合物及び発光性ドーパントの総質量を１００としたとき、ポリマーの含有量は５～８０質量％の範囲内であることが好ましい。
　上記範囲内であると、ポリマーが、電極側界面にも十分存在するため、発光層と隣接層間、又は、発光層と電極間において、電荷キャリアや化合物等の化学種の移動を制限することができ、電荷キャリアバランスが保たれ、有機ＥＬ素子の劣化や消光を引きおこす因子の発生を抑制できる。 (Optimal conditions for polymer)
When the total weight of the polymer, host compound and luminescent dopant is 100, the polymer content is preferably in the range of 5 to 80% by weight.
Within the above range, the polymer is sufficiently present at the interface on the electrode side, so that movement of chemical species such as charge carriers and compounds can be restricted between the light-emitting layer and the adjacent layer or between the light-emitting layer and the electrode. Thus, the charge carrier balance can be maintained, and the generation of factors that cause deterioration and quenching of the organic EL element can be suppressed.
　ポリマーの質量比は、より好ましくは、１５～６５質量％の範囲内であり、更に好ましくは、２０～６０質量％の範囲内である。 The mass ratio of the polymer is more preferably within the range of 15-65% by mass, and still more preferably within the range of 20-60% by mass.
　（ベンゼン環含有ポリマー）
　発光層と電極や隣接層との物理・化学的相互作用の観点から、ポリマーとしては、例えば上記構造式（１）～（３０）から選ばれるベンゼン環を含むポリマーであることが好ましい（ただし、構造式（１１）を除く）。 (Benzene ring-containing polymer)
From the viewpoint of physical and chemical interaction between the light-emitting layer and the electrode or adjacent layer, the polymer is preferably a polymer containing a benzene ring selected from the above structural formulas (1) to (30) (however, (except Structural Formula (11)).
　また、電極や隣接層との電子的相互作用のしやすさの観点から、上記構造式（１）～（３０）から選ばれるベンゼン環を側鎖に含むポリマーであることがより好ましい（ただし、構造式（１１）を除く）。 In addition, from the viewpoint of ease of electronic interaction with the electrode and adjacent layers, it is more preferable that the polymer contains a benzene ring selected from the above structural formulas (1) to (30) in the side chain (however, (except Structural Formula (11)).
　〔１．１．１．２〕発光性ドーパント
　有機ＥＬ素子の発光方式としては三重項励起状態から基底状態に戻る際に光を発する「リン光発光」と、一重項励起状態から基底状態に戻る際に光を発する「蛍光発光」の二通りがある。 [1.1.1.2] Luminescent dopant As for the light emission method of the organic EL device, there are two types of light emission methods, one is “phosphorescence emission” in which light is emitted when returning from the triplet excited state to the ground state, and the other is returning from the singlet excited state to the ground state. There are two kinds of "fluorescence emission" that emits light when the light is emitted.
　有機ＥＬ素子のような電界で励起する場合には、三重項励起子が７５％の確率で、一重項励起子が２５％の確率で生成するため、リン光発光の方が蛍光発光に比べ発光効率を高くすることが可能で、低消費電力化を実現するには優れた方式である。 When excited by an electric field like an organic EL device, triplet excitons are generated with a probability of 75% and singlet excitons are generated with a probability of 25%. It is an excellent method for achieving high efficiency and low power consumption.
　さらに、近年では、安達らの発見により一重項励起状態と三重項励起状態のエネルギーギャップを小さくすることで、発光中のジュール熱及び／又は発光素子が置かれる環境温度によりエネルギー準位の低い三重項励起状態から一重項励起状態に逆項間交差がおこり、結果としてほぼ１００％に近い蛍光発光を可能とする現象（熱活性型遅延蛍光又は熱励起型遅延蛍光ともいう：「ＴＡＤＦ」：ｔｈｅｒｍａｌｌｙ　ａｃｔｉｖａｔｅｄ　ｄｅｌａｙｅｄ　ｆｌｕｏｒｅｓｃｅｎｃｅ）とそれを可能にする蛍光発光性化合物が見い出されている（例えば非特許文献Ｈ．Ｕｏｙａｍａ，ｅｔ　ａｌ．，Ｎａｔｕｒｅ，２０１２，４９２，２３４－２３８、Ｈ．Ｎａｋａｎоｔａｎｉ，ｅｔ　ａｌ．，Ｎａｔｕｒｅ　Ｃｏｍｍｕｎｉｃａｉｏｎ，２０１４，５，４０１６－４０２２等参照。）。 Furthermore, in recent years, according to the discovery by Adachi et al., by reducing the energy gap between the singlet excited state and the triplet excited state, triplet A phenomenon in which reverse intersystem crossing occurs from a term excited state to a singlet excited state, and as a result, a phenomenon that enables nearly 100% fluorescence emission (also referred to as thermally activated delayed fluorescence or thermally excited delayed fluorescence: “TADF”: thermally activated delayed fluorescence) and fluorescent compounds that enable it have been found (for example, non-patent literature H. Uoyama, et al., Nature, 2012, 492, 234-238, H. Nakanotani, et al., Nature Communication, 2014, 5, 4016-4022, etc.).
　前記「リン光発光」及び「蛍光発光」に用いられる発光性ドーパントとしては、蛍光発光性ドーパント（蛍光ドーパント、蛍光性化合物ともいう。）又はリン光発光性ドーパント（リン光ドーパント、リン光性化合物ともいう。）が好ましく用いられる。
　発光層中の発光性ドーパントの濃度については、使用される特定のドーパント及びデバイスの必要条件に基づいて、任意に決定することができる。
　発光性ドーパントの濃度は、発光層の層厚方向に対し、均一な濃度で含有されていてもよいし、任意の濃度分布を有していてもよい。 As the luminescent dopant used in the above-mentioned "phosphorescence emission" and "fluorescence emission", a fluorescent dopant (also referred to as a fluorescent dopant or a fluorescent compound) or a phosphorescent dopant (phosphorescent dopant, phosphorescent compound Also called.) is preferably used.
The concentration of the emissive dopant in the emissive layer can be arbitrarily determined based on the particular dopant used and device requirements.
The concentration of the light-emitting dopant may be uniform in the layer thickness direction of the light-emitting layer, or may have an arbitrary concentration distribution.
　また、発光層には、複数種の発光性ドーパントが含まれていてもよい。
　例えば構造の異なるドーパント同士の組み合わせや、蛍光発光性ドーパントとリン光発光性ドーパントとを組み合わせて用いてもよい。
　これにより、任意の発光色を得ることができる。 Moreover, the light-emitting layer may contain a plurality of types of light-emitting dopants.
For example, dopants having different structures may be used in combination, or a fluorescent dopant and a phosphorescent dopant may be used in combination.
This makes it possible to obtain an arbitrary emission color.
　本発明の発光性ドーパントのドープの方法については、インクとして事前にホストと混合して塗布成膜しても良いし、ホスト層を形成しておき、後からドーパント液を塗布させることで発光層の陽極側界面まで浸透させる方法を用いても良い。 As for the doping method of the luminescent dopant of the present invention, it may be mixed with the host in advance as an ink and applied to form a film, or a host layer may be formed and then a dopant solution is applied to the luminescent layer. A method of penetrating to the interface on the anode side may be used.
　発光層内のポリマー、ホスト化合物及び発光性ドーパントの分布状態は、ダイナミック二次イオン質量分析法、スタティック二次イオン質量分析法、又はアルゴンクラスターイオンビームＸ線光電子分光法などにより基板に対して垂直（深さ）方向の発光層の組成を分析することで知ることができる。
　具体的には、リン光発光材に特異的な金属元素や、有機化合物内の特定の質量フラグメント又はヘテロ元素の有無を解析することによりナノメートルオーダーで発光層内の化合物の分布を観測することができる。 The distribution state of the polymer, host compound, and luminescent dopant in the light-emitting layer is measured perpendicular to the substrate by dynamic secondary ion mass spectrometry, static secondary ion mass spectrometry, or argon cluster ion beam X-ray photoelectron spectroscopy. It can be known by analyzing the composition of the light-emitting layer in the (depth) direction.
Specifically, by analyzing the presence or absence of metal elements specific to phosphorescent materials, specific mass fragments, or heteroelements in organic compounds, the distribution of compounds in the light-emitting layer can be observed on the order of nanometers. can be done.
　（リン光発光性ドーパント）
　リン光発光性ドーパントは、励起三重項からの発光が観測される化合物であり、具体的には、室温（２５℃）にてリン光発光する化合物であり、２５℃においてリン光量子収率が０．０１以上の化合物である。
　発光層に用いられるリン光発光性ドーパントにおいて、好ましいリン光量子収率は０．１以上である。 (phosphorescent dopant)
The phosphorescent dopant is a compound in which emission from excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25°C), and has a phosphorescence quantum yield of 0 at 25°C. .01 or higher.
The phosphorescent dopant used in the light-emitting layer preferably has a phosphorescence quantum yield of 0.1 or more.
　上記リン光量子収率は、第４版実験化学講座７の分光IIの３９８頁（１９９２年版、丸善）に記載の方法により測定できる。
　溶液中でのリン光量子収率は種々の溶媒を用いて測定できる。
　発光層に用いられるリン光発光性ドーパントは、任意の溶媒のいずれかにおいて上記リン光量子収率（０．０１以上）が達成されればよい。 The phosphorescence quantum yield can be measured by the method described in Experimental Chemistry Course 7, 4th Edition, Spectroscopy II, page 398 (1992 edition, Maruzen).
Phosphorescence quantum yield in solution can be measured using various solvents.
The phosphorescence-emitting dopant used in the light-emitting layer should achieve the phosphorescence quantum yield (0.01 or more) in any solvent.
　リン光発光性ドーパントは、有機ＥＬ素子の発光層に使用される公知の材料から適宜選択して用いることができる。
　本発明に使用できる公知のリン光発光性ドーパントの具体例としては、以下の文献に記載されている化合物等が挙げられる。 The phosphorescent dopant can be appropriately selected from known materials used in the light-emitting layer of organic EL devices and used.
Specific examples of known phosphorescent dopants that can be used in the present invention include the compounds described in the following documents.
　Ｎａｔｕｒｅ　３９５，１５１（１９９８）、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．７８，１６２２（２００１）、Ａｄｖ．Ｍａｔｅｒ．１９，７３９（２００７）、Ｃｈｅｍ．Ｍａｔｅｒ．１７，３５３２（２００５）、Ａｄｖ．Ｍａｔｅｒ．１７，１０５９（２００５）、国際公開第２００９／１００９９１号、国際公開第２００８／１０１８４２号、国際公開第２００３／０４０２５７号、米国特許出願公開第２００６／８３５４６９号明細書、米国特許出願公開第２００６／０２０２１９４号明細書、米国特許出願公開第２００７／００８７３２１号明細書、米国特許出願公開第２００５／０２４４６７３号明細書、Ｉｎｏｒｇ．Ｃｈｅｍ．４０，１７０４（２００１）、Ｃｈｅｍ．Ｍａｔｅｒ．１６，２４８０（２００４）、Ａｄｖ．Ｍａｔｅｒ．１６，２００３（２００４）、Ａｎｇｅｗ．Ｃｈｅｍ．ｌｎｔ．Ｅｄ．２００６，４５，７８００、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．８６，１５３５０５（２００５）、Ｃｈｅｍ．Ｌｅｔｔ．３４，５９２（２００５）、Ｃｈｅｍ．Ｃｏｍｍｕｎ．２９０６（２００５）、Ｉｎｏｒｇ．Ｃｈｅｍ．４２，１２４８（２００３）、国際公開第２００９／０５０２９０号、国際公開第２００２／０１５６４５号、国際公開第２００９／０００６７３号、米国特許出願公開第２００２／００３４６５６号明細書、米国特許第７３３２２３２号明細書、米国特許出願公開第２００９／０１０８７３７号明細書、米国特許出願公開第２００９／００３９７７６号明細書、米国特許第６９２１９１５号明細書、米国特許第６６８７２６６号明細書、米国特許出願公開第２００７／０１９０３５９号明細書、米国特許出願公開第２００６／０００８６７０号明細書、米国特許出願公開第２００９／０１６５８４６号明細書、米国特許出願公開第２００８／００１５３５５号明細書、米国特許第７２５０２２６号明細書、米国特許第７３９６５９８号明細書、米国特許出願公開第２００６／０２６３６３５号明細書、米国特許出願公開第２００３／０１３８６５７号明細書、米国特許出願公開第２００３／０１５２８０２号明細書、米国特許第７０９０９２８号明細書、Ａｎｇｅｗ．Ｃｈｅｍ．ｌｎｔ．Ｅｄ．４７，１（２００８）、Ｃｈｅｍ．Ｍａｔｅｒ．１８，５１１９（２００６）、Ｉｎｏｒｇ．Ｃｈｅｍ．４６，４３０８（２００７）、Ｏｒｇａｎｏｍｅｔａｌｌｉｃｓ　２３，３７４５（２００４）、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．７４，１３６１（１９９９）、国際公開第２００２／００２７１４号、国際公開第２００６／００９０２４号、国際公開第２００６／０５６４１８号、国際公開第２００５／０１９３７３号、国際公開第２００５／１２３８７３号、国際公開第２００５／１２３８７３号、国際公開第２００７／００４３８０号、国際公開第２００６／０８２７４２号、米国特許出願公開第２００６／０２５１９２３号明細書、米国特許出願公開第２００５／０２６０４４１号明細書、米国特許第７３９３５９９号明細書、米国特許第７５３４５０５号明細書、米国特許第７４４５８５５号明細書、米国特許出願公開第２００７／０１９０３５９号明細書、米国特許出願公開第２００８／０２９７０３３号明細書、米国特許第７３３８７２２号明細書、米国特許出願公開第２００２／０１３４９８４号明細書、米国特許第７２７９７０４号明細書、米国特許出願公開第２００６／０９８１２０号明細書、米国特許出願公開第２００６／１０３８７４号明細書、国際公開第２００５／０７６３８０号、国際公開第２０１０／０３２６６３号、国際公開第２００８１４０１１５号、国際公開第２００７／０５２４３１号、国際公開第２０１１／１３４０１３号、国際公開第２０１１／１５７３３９号、国際公開第２０１０／０８６０８９号、国際公開第２００９／１１３６４６号、国際公開第２０１２／０２０３２７号、国際公開第２０１１／０５１４０４号、国際公開第２０１１／００４６３９号、国際公開第２０１１／０７３１４９号、米国特許出願公開第２０１２／２２８５８３号明細書、米国特許出願公開第２０１２／２１２１２６号明細書、特開２０１２－０６９７３７号公報、特開２０１２－１９５５５４号公報、特開２００９－１１４０８６号公報、特開２００３－８１９８８号公報、特開２００２－３０２６７１号公報及び特開２００２－３６３５５２号公報等である。 　Nature 395, 151 (1998), Appl. Phys. Lett. 78, 1622 (2001), Adv. Mater. 19, 739 (2007), Chem. Mater. 17, 3532 (2005), Adv. Mater. 17, 1059 (2005), WO 2009/100991, WO 2008/101842, WO 2003/040257, U.S. Patent Application Publication No. 2006/835469, U.S. Patent Application Publication No. 2006/ 0202194, US Patent Application Publication No. 2007/0087321, US Patent Application Publication No. 2005/0244673, Inorg. Chem. 40, 1704 (2001), Chem. Mater. 16, 2480 (2004), Adv. Mater. 16, 2003 (2004), Angew. Chem. lnt. Ed. 2006, 45, 7800, Appl. Phys. Lett. 86, 153505 (2005), Chem. Lett. 34, 592 (2005), Chem. Commun. 2906 (2005), Inorg. Chem. 42, 1248 (2003), WO 2009/050290, WO 2002/015645, WO 2009/000673, US 2002/0034656, US 7332232 , US2009/0108737, US2009/0039776, US6921915, US6687266, US2007/0190359 Specification, US Patent Application Publication No. 2006/0008670, US Patent Application Publication No. 2009/0165846, US Patent Application Publication No. 2008/0015355, US Patent No. 7250226, US Patent No. 7396598, US2006/0263635, US2003/0138657, US2003/0152802, US7090928, Angew . Chem. lnt. Ed. 47, 1 (2008), Chem. Mater. 18, 5119 (2006), Inorg. Chem. 46, 4308 (2007), Organometallics 23, 3745 (2004), Appl. Phys. Lett. 74, 1361 (1999), WO 2002/002714, WO 2006/009024, WO 2006/056418, WO 2005/019373, WO 2005/123873, WO 2005/123873 2005/123873, WO2007/004380, WO2006/082742, US2006/0251923, US2005/0260441, US7393599 Specification, US7534505, US7445855, US2007/0190359, US2008/0297033, US7338722 , US2002/0134984, US7279704, US2006/098120, US2006/103874, WO2005/ 076380, WO 2010/032663, WO 2008140115, WO 2007/052431, WO 2011/134013, WO 2011/157339, WO 2010/086089, International Publication No. 2009/113646, WO 2012/020327, WO 2011/051404, WO 2011/004639, WO 2011/073149, US Patent Application Publication No. 2012/228583 , US Patent Application Publication No. 2012/212126, JP 2012-069737, JP 2012-195554, JP 2009-114086, JP 2003-81988, JP 2002-302671 JP-A-2002-363552 and the like.
　中でも、好ましいリン光発光性ドーパントとしては、Ｉｒを中心金属に有する有機金属錯体が挙げられる。
　更に好ましくは、金属－炭素結合、金属－窒素結合、金属－酸素結合、金属－硫黄結合の少なくとも一つの配位様式を含む錯体が好ましい。 Among them, preferred phosphorescent dopants include organometallic complexes having Ir as a central metal.
Complexes containing at least one coordination mode of metal-carbon bond, metal-nitrogen bond, metal-oxygen bond, and metal-sulfur bond are more preferred.
　（蛍光発光性ドーパント）
　蛍光発光性ドーパントは、励起一重項からの発光が可能な化合物であり、励起一重項からの発光が観測される限り特に限定されない。 (Fluorescent dopant)
The fluorescent dopant is a compound capable of emitting light from an excited singlet, and is not particularly limited as long as light emission from an excited singlet can be observed.
　蛍光発光性ドーパントしては、例えばアントラセン誘導体、ピレン誘導体、クリセン誘導体、フルオランテン誘導体、ペリレン誘導体、フルオレン誘導体、アリールアセチレン誘導体、スチリルアリーレン誘導体、スチリルアミン誘導体、アリールアミン誘導体、ホウ素錯体、クマリン誘導体、ピラン誘導体、シアニン誘導体、クロコニウム誘導体、スクアリウム誘導体、オキソベンツアントラセン誘導体、フルオレセイン誘導体、ローダミン誘導体、ピリリウム誘導体、ペリレン誘導体、ポリチオフェン誘導体、又は希土類錯体系化合物等が挙げられる。 Examples of fluorescent dopants include anthracene derivatives, pyrene derivatives, chrysene derivatives, fluoranthene derivatives, perylene derivatives, fluorene derivatives, arylacetylene derivatives, styrylarylene derivatives, styrylamine derivatives, arylamine derivatives, boron complexes, coumarin derivatives, pyran derivatives, cyanine derivatives, croconium derivatives, squarium derivatives, oxobenzanthracene derivatives, fluorescein derivatives, rhodamine derivatives, pyrylium derivatives, perylene derivatives, polythiophene derivatives, rare earth complex compounds, and the like.
　（遅延蛍光化合物）
　《励起三重項－三重項消滅（ＴＴＡ）遅延蛍光化合物》
　蛍光発光性化合物の問題点を解決すべく登場したのが遅延蛍光を利用した発光方式である。
　三重項励起子同士の衝突を起源とするＴＴＡ方式は、下記のような一般式で記述できる。
　すなわち、従来、励起子のエネルギーが、無輻射失活により、熱にしか変換されなかった三重項励起子の一部が、発光に寄与しうる一重項励起子に逆項間交差できるメリットがあり、実際の有機ＥＬ素子においても従来の蛍光発光素子の約２倍の外部取り出し量子効率を得ることができている。 (Delayed fluorescence compound)
<<Excited triplet-triplet annihilation (TTA) delayed fluorescence compound>>
A luminescence method using delayed fluorescence has emerged to solve the problems of fluorescent compounds.
The TTA method originating from collisions between triplet excitons can be described by the following general formula.
That is, conventionally, exciton energy is converted only to heat by non-radiative deactivation, but some of the triplet excitons have the advantage of being able to reverse intersystem crossover to singlet excitons that can contribute to light emission. In actual organic EL devices, it is possible to obtain an external extraction quantum efficiency approximately double that of conventional fluorescent light emitting devices.
　一般式：Ｔ＊＋Ｔ＊→Ｓ＊＋Ｓ（式中、Ｔ＊は三重項励起子、Ｓ＊は一重項励起子、Ｓは基底状態分子を表す。）
　しかしながら、上式からもわかるように、二つの三重項励起子から発光に利用できる一重項励起子は一つしか生成しないため、この方式で１００％の内部量子効率を得ることは原理上できない。 General formula: T * +T * →S * +S (Wherein, T * represents a triplet exciton, S * represents a singlet exciton, and S represents a ground state molecule.)
However, as can be seen from the above equation, only one singlet exciton that can be used for light emission is generated from two triplet excitons, so it is impossible in principle to obtain 100% internal quantum efficiency with this method.
　《熱活性型遅延蛍光（ＴＡＤＦ）化合物》
　もう一つの高効率蛍光発光であるＴＡＤＦ方式は、ＴＴＡの問題点を解決できる方式である。 <<Thermal activated delayed fluorescence (TADF) compound>>
The TADF method, which is another high-efficiency fluorescence emission method, is a method that can solve the problems of TTA.
　蛍光発光性化合物は、前記のごとく無限に分子設計できる利点を持っている。
　すなわち、分子設計された化合物の中で、特異的に三重項励起状態と一重項励起状態のエネルギー準位差（以下において、適宜、「ΔＥＳＴ」と略記する。）が極めて近接する化合物が存在する。 Fluorescent compounds have the advantage that they can be designed indefinitely as described above.
That is, among molecularly designed compounds, there are compounds in which the energy level difference between the triplet excited state and the singlet excited state (hereinafter, appropriately abbreviated as " ΔEST ") is extremely close. do.
　このような化合物は、分子内に重原子を持っていないにもかかわらず、ΔＥＳＴが小さいために通常では起こりえない三重項励起状態から一重項励起状態への逆項間交差が起こる。
　さらに、一重項励起状態から基底状態への失活（＝蛍光発光）の速度定数が極めて大きいことから、三重項励起子はそれ自体が基底状態に熱的に失活（無輻射失活）するよりも、一重項励起状態経由で蛍光を発しながら基底状態に戻る方が速度論的に有利である。
　そのため、ＴＡＤＦでは理論的には１００％の蛍光発光が可能となる。 Such a compound does not have a heavy atom in the molecule, but reverse intersystem crossing from a triplet excited state to a singlet excited state, which cannot normally occur due to a small ΔEST , occurs.
Furthermore, since the rate constant of deactivation (= fluorescence emission) from the singlet excited state to the ground state is extremely large, the triplet exciton itself is thermally deactivated to the ground state (non-radiative deactivation). It is kinetically advantageous to return to the ground state while emitting fluorescence via the singlet excited state.
Therefore, TADF theoretically enables 100% fluorescence emission.
　蛍光発光性ドーパントして、遅延蛍光を発する化合物（遅延蛍光発光性化合物及び熱活性型遅延蛍光化合物）の例としては、国際公開第２０１１／１５６７９３号、特開２０１１－２１３６４３号公報、特開２０１０－９３１８１号公報、特許５３６６１０６号、国際公開第２０１３／１６１４３７号及び国際公開第２０１６／１５８５４０号等に記載の化合物が挙げられるが、本発明はこれらに限定されない。 As a fluorescent dopant, examples of compounds that emit delayed fluorescence (delayed fluorescence-emitting compounds and thermally activated delayed fluorescence compounds) include International Publication No. 2011/156793, JP-A-2011-213643, and JP-A-2010. -93181, Japanese Patent No. 5366106, WO 2013/161437 and WO 2016/158540, etc., but the present invention is not limited thereto.
　また本発明では、発光層に含有される発光素子として、量子ドット含有有機発光素子（ＱＤ－ＯＬＥＤ）を用いることも可能であり、例えば特開２０１４－０７７０４６号公報、特開２０１４－０７８３８０号公報、特開２０１４－０７８３８１号公報、特開２０１７－１０１１２８号公報等に記載されている構成を参照することができる。 Further, in the present invention, it is possible to use a quantum dot-containing organic light-emitting device (QD-OLED) as a light-emitting device contained in the light-emitting layer. , JP-A-2014-078381, JP-A-2017-101128, etc. can be referred to.
　また、量子ドットを含有する無機発光素子（ＱＬＥＤ）としては、例えば特開２０１５－１５６３６７号公報及び特開２０１８－０７８２７９号公報に記載されている内容を参照することができる。 In addition, as an inorganic light emitting device (QLED) containing quantum dots, for example, the contents described in JP-A-2015-156367 and JP-A-2018-078279 can be referred to.
　さらに、本発明に係る発光層は、ペロブスカイト化合物を含有する層としてもよい。 Furthermore, the light-emitting layer according to the present invention may be a layer containing a perovskite compound.
　本発明において、「ペロブスカイト化合物」とは、ペロブスカイト構造を有する化合物をいう。
　ペロブスカイト化合物は、有機物及び無機物がペロブスカイト構造の構成要素となっているペロブスカイト化合物（有機無機ハイブリッド構造のペロブスカイト化合物）であることが好ましい。 In the present invention, "perovskite compound" means a compound having a perovskite structure.
The perovskite compound is preferably a perovskite compound in which an organic substance and an inorganic substance are constituent elements of the perovskite structure (a perovskite compound with an organic-inorganic hybrid structure).
　本発明においては、ペロブスカイト化合物が、下記一般式（ａ）で表される構造を有することが、光電変換効率の観点から好ましい。 In the present invention, the perovskite compound preferably has a structure represented by the following general formula (a) from the viewpoint of photoelectric conversion efficiency.
　一般式（ａ）：Ｒ－Ｍ－Ｘ
　上記一般式（ａ）において、Ｒは有機分子を表す。Ｍは金属原子を表す。Ｘはハロゲン原子又はカルコゲン原子を表す。 General formula (a): RMX
In the above general formula (a), R represents an organic molecule. M represents a metal atom. X represents a halogen atom or a chalcogen atom.
　上記一般式（ａ）において、Ｒは有機分子であり、ＣｌＮｍＸｎ（ｌ、ｍ及びｎはいずれも正の整数を表す。）で示される分子であることが好ましい。 In the above general formula (a), R is an organic molecule, preferably a molecule represented by C1NmXn ( l , m and n all represent positive integers).
　Ｒは、具体的には、メチルアミン、エチルアミン、プロピルアミン、ブチルアミン、ペンチルアミン、ヘキシルアミン、ジメチルアミン、ジエチルアミン、ジプロピルアミン、ジブチルアミン、ジペンチルアミン、ジヘキシルアミン、トリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン、トリペンチルアミン、トリヘキシルアミン、エチルメチルアミン、メチルプロピルアミン、ブチルメチルアミン、メチルペンチルアミン、ヘキシルメチルアミン、エチルプロピルアミン、エチルブチルアミン、イミダゾール、アゾール、ピロール、アジリジン、アジリン、アゼチジン、アゼト、イミダゾリン、カルバゾール及びこれらのイオン（例えばメチルアンモニウム（ＣＨ３ＮＨ３）等）やフェネチルアンモニウム等が挙げられる。
　中でも、メチルアミン、エチルアミン、プロピルアミン、ブチルアミン、ペンチルアミン、ヘキシルアミン及びこれらのイオンやフェネチルアンモニウムが好ましく、メチルアミン、エチルアミン、プロピルアミン及びこれらのイオンがより好ましい。 R is specifically methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, imidazole, azole, pyrrole, aziridine, azirine, azetidine, Azeto, imidazoline, carbazole and their ions (eg, methylammonium (CH 3 NH 3 ), etc.), phenethylammonium, and the like can be mentioned.
Among them, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine and their ions and phenethylammonium are preferred, and methylamine, ethylamine, propylamine and their ions are more preferred.
　Ｍは金属原子であり、鉛、スズ、亜鉛、チタン、アンチモン、ビスマス、ニッケル、鉄、コバルト、銀、銅、ガリウム、ゲルマニウム、マグネシウム、カルシウム、インジウム、アルミニウム、マンガン、クロム、モリブデン及びユウロピウム等が挙げられる。
　これらの元素は単独で用いられてもよく、二種以上が併用されてもよい。 M is a metal atom such as lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum and europium. mentioned.
These elements may be used alone, or two or more of them may be used in combination.
　Ｘはハロゲン原子又はカルコゲン原子であり、例えば塩素、臭素、ヨウ素、硫黄、セレン等が挙げられる。
　これらの元素は単独で用いられてもよく、二種以上が併用されてもよい。
　中でも、構造中にハロゲン原子を含有することで、上記ペロブスカイト化合物が有機溶媒に可溶になり、安価な印刷法等への適用が可能になることから、ハロゲン原子が好ましい。
　さらに、上記有機無機ペロブスカイト化合物のエネルギーバンドギャップが狭くなることから、ヨウ素がより好ましい。 X is a halogen atom or a chalcogen atom such as chlorine, bromine, iodine, sulfur, selenium and the like.
These elements may be used alone, or two or more of them may be used in combination.
Among them, a halogen atom is preferable because the perovskite compound becomes soluble in an organic solvent by containing a halogen atom in the structure, and application to an inexpensive printing method or the like becomes possible.
Furthermore, iodine is more preferable because it narrows the energy bandgap of the organic-inorganic perovskite compound.
　本発明に用いることのできる発光性ドーパントとしては、例えば以下のものが挙げられる。 Examples of luminescent dopants that can be used in the present invention include the following.
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
　〔１．１．１．３〕ホスト化合物
　ホスト化合物は、発光層において主に電荷の注入及び輸送を担う化合物であり、有機ＥＬ素子においてそれ自体の発光は実質的に観測されない。 [1.1.1.3] Host compound The host compound is a compound that is mainly responsible for charge injection and transport in the light-emitting layer, and its own light emission is substantially not observed in the organic EL device.
　本発明の有機ＥＬ素子は、複数の発光画素が、共通の電極及び共通のホスト化合物を有することを特徴とするものであるが、前記ホスト化合物が複数種のホスト化合物からなり、前記複数の発光画素において前記複数種のホスト化合物の組成比が等しいことが好ましい。
　ホスト化合物を複数種用いることで、電荷の移動を調整することが可能であり、有機ＥＬ素子の高効率化が可能となる。 The organic EL device of the present invention is characterized in that a plurality of light-emitting pixels have a common electrode and a common host compound, wherein the host compound is composed of a plurality of types of host compounds, and the plurality of light-emitting pixels It is preferable that the composition ratios of the plurality of types of host compounds are equal in the pixel.
By using a plurality of types of host compounds, it is possible to adjust the movement of electric charges, and it is possible to improve the efficiency of the organic EL device.
　発光層に用いられるホスト化合物としては、従来有機ＥＬ素子で用いられる化合物を用いることができる。
　例えば低分子化合物や、繰り返し単位を有する高分子化合物でもよいし、ビニル基やエポキシ基のような反応性基を有する化合物でもよい。 As the host compound used in the light-emitting layer, compounds conventionally used in organic EL devices can be used.
For example, it may be a low-molecular compound, a polymer compound having repeating units, or a compound having a reactive group such as a vinyl group or an epoxy group.
　公知のホスト化合物としては、正孔輸送能又は電子輸送能を有しつつ、発光の長波長化を防ぎ、更に、有機ＥＬ素子を高温駆動時や素子駆動中の発熱に対する安定性の観点から、高いガラス転移温度（Ｔｇ）を有することが好ましい。
　ホスト化合物としては、Ｔｇが８０℃以上であることが好ましく、より好ましくは１００℃以上である。 As a known host compound, from the viewpoint of stability against heat generation during high-temperature driving of an organic EL device or during driving of the device, It preferably has a high glass transition temperature (Tg).
The host compound preferably has a Tg of 80° C. or higher, more preferably 100° C. or higher.
　ここで、「ガラス転移点（Ｔｇ）」とは、ＤＳＣ（Ｄｉｆｆｅｒｅｎｔｉａｌ　Ｓｃａｎｎｉｎｇ　Ｃｏｌｏｒｉｍｅｔｒｙ：示差走査熱量法）を用いて、ＪＩＳ－Ｋ－７１２１に準拠した方法により求められる値である。 Here, the "glass transition point (Tg)" is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).
　ホスト化合物は、駆動安定性の観点から、カチオンラジカル状態、アニオンラジカル状態、及び励起状態の全ての活性種の状態において安定に存在でき、分解や付加反応などの化学変化を起こさないこと、更に、層中において通電経時でホスト分子がオングストロームレベルで移動しないことが好ましい。 From the viewpoint of driving stability, the host compound must be able to exist stably in all active species states of cation radical state, anion radical state, and excited state, and not undergo chemical changes such as decomposition and addition reactions. It is preferred that the host molecules do not migrate at the angstrom level in the layer during the passage of current.
　本発明に用いることができるホスト化合物としては、特に制限はなく、従来有機ＥＬ素子で用いられる化合物を用いることができる。
　代表的にはカルバゾール誘導体、トリアリールアミン誘導体、芳香族誘導体、含窒素複素環化合物、チオフェン誘導体、フラン誘導体、オリゴアリーレン化合物等の基本骨格を有するもの、又は、カルボリン誘導体やジアザカルバゾール誘導体（ここで、ジアザカルバゾール誘導体とは、カルボリン誘導体のカルボリン環を構成する炭化水素環の少なくとも一つの炭素原子が窒素原子で置換されているものを表す。）等が挙げられる。 The host compound that can be used in the present invention is not particularly limited, and compounds that are conventionally used in organic EL devices can be used.
Representative examples are those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, etc., or carboline derivatives and diazacarbazole derivatives (here and the diazacarbazole derivative means that at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.) and the like.
　本発明に用いることができる公知のホスト化合物としては正孔輸送能、電子輸送能を有しつつ、かつ、発光の長波長化を防ぎ、なおかつ前記したように高Ｔｇである化合物が好ましい。 A known host compound that can be used in the present invention is preferably a compound that has hole-transporting ability and electron-transporting ability, prevents emission from becoming longer in wavelength, and has a high Tg as described above.
　また、本発明においては、従来公知のホスト化合物を単独で用いてもよく、又は複数種併用して用いてもよい。
　ホスト化合物を複数種用いることで、電荷の移動を調整することが可能であり、有機ＥＬ素子を高効率化することができる。
　また、従来公知の化合物を複数種用いることで、異なる発光を混ぜることが可能となり、これにより任意の発光色を得ることができる。 Moreover, in the present invention, a conventionally known host compound may be used alone, or a plurality of types may be used in combination.
By using a plurality of types of host compounds, it is possible to adjust the movement of electric charges, and to improve the efficiency of the organic EL device.
In addition, by using a plurality of conventionally known compounds, it is possible to mix different luminescence, thereby obtaining an arbitrary luminescence color.
　また、本発明に用いられるホスト化合物としては、低分子化合物でも、繰り返し単位をもつ高分子化合物でもよく、ビニル基やエポキシ基のような重合性基を有する低分子化合物（重合性ホスト化合物）でもよく、このような化合物を一種又は複数種用いても良い。 The host compound used in the present invention may be a low-molecular-weight compound, a high-molecular-weight compound having a repeating unit, or a low-molecular-weight compound (polymerizable host compound) having a polymerizable group such as a vinyl group or an epoxy group. Well, one or more of such compounds may be used.
　本発明の有機ＥＬ素子に公知のホスト化合物を用いる場合、その具体例としては、以下の文献に記載の化合物等が挙げられるが、本発明はこれらに限定されない。 When a known host compound is used in the organic EL device of the present invention, specific examples thereof include compounds described in the following documents, but the present invention is not limited thereto.
　特開２００１－２５７０７６号公報、同２００２－３０８８５５号公報、同２００１－３１３１７９号公報、同２００２－３１９４９１号公報、同２００１－３５７９７７号公報、同２００２－３３４７８６号公報、同２００２－８８６０号公報、同２００２－３３４７８７号公報、同２００２－１５８７１号公報、同２００２－３３４７８８号公報、同２００２－４３０５６号公報、同２００２－３３４７８９号公報、同２００２－７５６４５号公報、同２００２－３３８５７９号公報、同２００２－１０５４４５号公報、同２００２－３４３５６８号公報、同２００２－１４１１７３号公報、同２００２－３５２９５７号公報、同２００２－２０３６８３号公報、同２００２－３６３２２７号公報、同２００２－２３１４５３号公報、同２００３－３１６５号公報、同２００２－２３４８８８号公報、同２００３－２７０４８号公報、同２００２－２５５９３４号公報、同２００２－２６０８６１号公報、同２００２－２８０１８３号公報、同２００２－２９９０６０号公報、同２００２－３０２５１６号公報、同２００２－３０５０８３号公報、同２００２－３０５０８４号公報、同２００２－３０８８３７号公報、同２０１６－１７８２７４号公報、米国特許出願公開第２００３／０１７５５５３号明細書、米国特許出願公開第２００６／０２８０９６５号明細書、米国特許出願公開第２００５／０１１２４０７号明細書、米国特許出願公開第２００９／００１７３３０号明細書、米国特許出願公開第２００９／００３０２０２号明細書、米国特許出願公開第２００５／０２３８９１９号明細書、国際公開第２００１／０３９２３４号、国際公開第２００９／０２１１２６号、国際公開第２００８／０５６７４６号、国際公開第２００４／０９３２０７号、国際公開第２００５／０８９０２５号、国際公開第２００７／０６３７９６号、国際公開第２００７／０６３７５４号、国際公開第２００４／１０７８２２号、国際公開第２００５／０３０９００号、国際公開第２００６／１１４９６６号、国際公開第２００９／０８６０２８号、国際公開第２００９／００３８９８号、国際公開第２０１２／０２３９４７号、特開２００８－０７４９３９号公報、特開２００７－２５４２９７号公報、欧州特許第２０３４５３８号明細書、国際公開第２０１１／０５５９３３号、国際公開第２０１２／０３５８５３号、特開２０１５－３８９４１号公報及び米国特許出願公開第２０１７／０５６８１４号明細書である。 JP 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357977, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227, 2002-231453, 2003 -3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, 2002-299060, 2002- 302516, 2002-305083, 2002-305084, 2002-308837, 2016-178274, US Patent Application Publication No. 2003/0175553, US Patent Application Publication No. 2006 US2005/0112407, US2009/0017330, US2009/0030202, US2005/0238919 No., WO 2001/039234, WO 2009/021126, WO 2008/056746, WO 2004/093207, WO 2005/089025, WO 2007/063796 WO 2007/063754, WO 2004/107822, WO 2005/030900, WO 2006/114966, WO 2009/086028, WO 2009/003898, WO 2012/023947, JP 2008-074939, JP 2007-254297, EP 2034538, WO 2011/055933, WO 2012/035853, Japanese Patent Application Publication No. 2015-38941 and US Patent Application Publication No. 2017/056814.
　その中でも、本発明のホスト化合物としては、非ハロゲン溶媒にも溶解するホスト化合物が好ましく、エステル系溶媒であることがさらに好ましい。
　ハロゲン溶媒であるとその下層を溶解してしまう問題があるからである。
　また、ホスト化合物の分子量としては、１０００以下であると溶解しやすいために好ましい。 Among them, the host compound of the present invention is preferably a host compound that dissolves in a non-halogen solvent, and more preferably an ester solvent.
This is because the halogen solvent has the problem of dissolving the lower layer.
Moreover, it is preferable that the molecular weight of the host compound is 1000 or less because it is easily dissolved.
　本発明に用いられるホスト化合物としては、以下の一般式で表される構造を有する化合物であることが好ましい。 The host compound used in the present invention is preferably a compound having a structure represented by the following general formula.
　（一般式（１）で表される構造を有する化合物）
　発光層は、下記一般式（１）で表される構造を有する化合物を含有する塗布液を用いて形成することが好ましい。 (Compound having a structure represented by general formula (1))
The light-emitting layer is preferably formed using a coating liquid containing a compound having a structure represented by the following general formula (1).
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000010
　〔一般式（１）中、Ｘは、Ｏ、Ｓ又はＮＲ９を表す。Ｒ９は、水素原子、重水素原子、アルキル基、アルケニル基、アルキニル基、アリールアルキル基、芳香族炭化水素環基、芳香族複素環基、非芳香族炭化水素環基、非芳香族複素環基又は下記一般式（２）で表される置換基を表す。Ｒ１～Ｒ８は、それぞれ、水素原子、重水素原子、ハロゲン原子、シアノ基、アルキル基、アルケニル基、アルキニル基、アルコキシ基、アシル基、アミノ基、シリル基、ホスフィンオキシド基、芳香族炭化水素環基、芳香族複素環基、非芳香族炭化水素環基、非芳香族複素環基又は下記一般式（２）で表される置換基を表す。Ｒ１～Ｒ９の少なくとも一つは、下記一般式（２）で表される置換基を表す。Ｒ１～Ｒ９は、互いに同じであっても異なっていても良く、更に置換基を有していても良い。〕 [In general formula (1), X represents O, S, or NR9. R 9 is a hydrogen atom, deuterium atom, alkyl group, alkenyl group, alkynyl group, arylalkyl group, aromatic hydrocarbon ring group, aromatic heterocyclic group, non-aromatic hydrocarbon ring group, non-aromatic heterocyclic ring group or a substituent represented by the following general formula (2). R 1 to R 8 each represent a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an acyl group, an amino group, a silyl group, a phosphine oxide group, and an aromatic hydrocarbon group. It represents a hydrogen ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group, a non-aromatic heterocyclic group, or a substituent represented by the following general formula (2). At least one of R 1 to R 9 represents a substituent represented by general formula (2) below. R 1 to R 9 may be the same or different, and may have a substituent. ]
Figure JPOXMLDOC01-appb-C000011
Figure JPOXMLDOC01-appb-C000011
　〔一般式（２）中、Ｌは、それぞれ、アルキレン基、アルケニレン基、ｏ－フェニレン基、ｍ－フェニレン基、ｐ－フェニレン基、アミド基又は二価の芳香族複素環基を表し、更に置換基を有していても良い。ｎは、１～８の整数を表す。ｎが２以上の整数を表す場合、２以上のＬは、互いに同じであっても異なっていても良い。Ｒは、炭素原子数１～２０のアルキル基、炭素原子数１～２０のアルコキシ基、炭素原子数１～２０のフッ化アルキル基、芳香族炭化水素環基、芳香族複素環基又は非芳香族炭化水素環基を表し、更に置換基を有していても良い。ｍは、１～３の整数を表す。Ｌ及びＲのうち少なくとも一つはアルキレン基又はアルキル基を表す。一般式（２）で表される置換基が複数ある場合、Ｌ及びＲは、互いに同じであっても異なっていても良いが、互いに連結し環を形成することはない。〕 [In the general formula (2), each L represents an alkylene group, an alkenylene group, an o-phenylene group, an m-phenylene group, a p-phenylene group, an amide group or a divalent aromatic heterocyclic group, and further substituted You may have a group. n represents an integer of 1 to 8; When n represents an integer of 2 or more, 2 or more L's may be the same or different. R is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group or a non-aromatic represents a group hydrocarbon ring group, which may further have a substituent. m represents an integer of 1 to 3; At least one of L and R represents an alkylene group or an alkyl group. When there are a plurality of substituents represented by general formula (2), L and R may be the same or different, but are not linked to form a ring. ]
　上記一般式（１）におけるＲ１～Ｒ９で表される置換基は、前記一般式（I）～（III）におけるＲ１～Ｒ６と同義である。また、上記一般式（２）におけるＬで表される連結基は、前記一般式（I）及び（II）におけるＬと同義である。 The substituents represented by R 1 to R 9 in general formula (1) have the same meanings as R 1 to R 6 in general formulas (I) to (III). In addition, the linking group represented by L in the general formula (2) has the same definition as L in the general formulas (I) and (II).
　上記一般式（２）において、Ｒで表される炭素原子数１～２０のアルキル基としては、例えば上記一般式（１）においてＲ１～Ｒ９で表されるアルキル基として挙げられたもののうち、炭素原子数が１～２０の基が挙げられる。 In the general formula (2), the alkyl group having 1 to 20 carbon atoms represented by R includes, for example, those listed as the alkyl groups represented by R 1 to R 9 in the general formula (1). , groups having 1 to 20 carbon atoms.
　Ｒで表される炭素原子数１～２０のフッ化アルキル基としては、例えば上記炭素原子数１～２０のアルキル基の水素原子がフッ素原子に置換した基が挙げられる。 Examples of the fluorinated alkyl group having 1 to 20 carbon atoms represented by R include groups in which hydrogen atoms of the above alkyl groups having 1 to 20 carbon atoms are substituted with fluorine atoms.
　Ｒで表される炭素原子数１～２０のアルコキシ基としては、例えば上記一般式（１）においてＲ１～Ｒ８で表されるアルコキシ基として挙げられたもののうち、炭素原子数が１～２０の基が挙げられる。 Examples of the alkoxy group having 1 to 20 carbon atoms represented by R include those having 1 to 20 carbon atoms among the alkoxy groups represented by R 1 to R 8 in the above general formula (1). group.
　Ｒで表される芳香族炭化水素環基、芳香族複素環基又は非芳香族炭化水素環基としては、例えば上記一般式（１）においてＲ１～Ｒ９で表される芳香族炭化水素環基、芳香族複素環基又は非芳香族炭化水素環基と同様のものが挙げられる。 The aromatic hydrocarbon ring group, aromatic heterocyclic group or non-aromatic hydrocarbon ring group represented by R includes, for example, aromatic hydrocarbon rings represented by R 1 to R 9 in the general formula (1) groups, aromatic heterocyclic groups or non-aromatic hydrocarbon ring groups.
　上記一般式（２）において、Ｌ及びＲが更に有していても良い置換基としては、例えば上記一般式（１）においてＲ１～Ｒ９が有していても良い置換基と同様のものが挙げられる。 In general formula (2), the substituents that L and R may further have include, for example, the same substituents that R 1 to R 9 may have in general formula (1). is mentioned.
　上記一般式（１）で表される構造を有する化合物としては、一般式（２）で表される置換基のうち、少なくとも一つのＬが炭素原子数１～６のアルキレン基であるものが好ましく、また、一般式（２）で表される置換基のうち、少なくとも一つのＲが炭素原子数１～６のアルキル基であるものが好ましい。 As the compound having the structure represented by the general formula (1), among the substituents represented by the general formula (2), at least one L is preferably an alkylene group having 1 to 6 carbon atoms. Also, among the substituents represented by formula (2), at least one R is preferably an alkyl group having 1 to 6 carbon atoms.
　以下、本発明に係る一般式（１）で表される構造を有する化合物の具体例を示すが、これらに限られるものではない。 Specific examples of the compound having the structure represented by the general formula (1) according to the present invention are shown below, but are not limited to these.
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000013
Figure JPOXMLDOC01-appb-C000013
Figure JPOXMLDOC01-appb-C000014
Figure JPOXMLDOC01-appb-C000014
Figure JPOXMLDOC01-appb-C000015
Figure JPOXMLDOC01-appb-C000015
Figure JPOXMLDOC01-appb-C000016
Figure JPOXMLDOC01-appb-C000016
　〔１．１．２〕電荷キャリア輸送層
　「電荷キャリア輸送層（「電荷輸送層」ともいう。）」とは、電荷キャリアすなわち電子又は正孔を輸送する機能を有する化合物を含有する層をいう。
　以下においては、電荷キャリア輸送層（「電荷輸送層」）を「電子輸送層」と「正孔輸送層」に分けて説明する。 [1.1.2] Charge carrier transport layer “Charge carrier transport layer (also referred to as “charge transport layer”)” refers to a layer containing a compound having a function of transporting charge carriers, that is, electrons or holes. .
In the following, the charge carrier transport layer (“charge transport layer”) is divided into an “electron transport layer” and a “hole transport layer” for explanation.
　〔１．１．２．１〕電子輸送層
　「電子輸送層」とは、電荷キャリアのうち電子を輸送する機能を有する材料からなり、広い意味で電子注入層も電子輸送層に含まれる。
　電子輸送層は単層又は複数層設けることができる。 [1.1.2.1] Electron transport layer The “electron transport layer” is made of a material having a function of transporting electrons among charge carriers, and in a broad sense, an electron injection layer is also included in the electron transport layer.
The electron transport layer can be provided as a single layer or multiple layers.
　また、電子輸送層は、以下に説明する電子輸送材料を含有する塗布液を用いて形成することが好ましい。
　また、当該塗布液は前記極性フッ化溶媒を含有することが好ましい。
　極性フッ化溶媒に対する溶解度は、電子輸送層の材料、絶縁層の材料、発光層の材料の順に低くなることが好ましい。 Also, the electron transport layer is preferably formed using a coating liquid containing an electron transport material described below.
Moreover, the coating liquid preferably contains the polar fluorinated solvent.
The solubility in the polar fluorinated solvent is preferably lower in the order of the material of the electron transport layer, the material of the insulating layer, and the material of the light emitting layer.
　従来、電子輸送層（複数層とする場合は陰極側に隣接する電子輸送層）に用いられる電子輸送材料としては、陰極より注入された電子を発光層に伝達する機能を有していれば良く、その材料としては従来公知の化合物の中から任意のものを選択して用いることができる。
　例えばフルオレン誘導体、カルバゾール誘導体、アザカルバゾール誘導体、オキサジアゾール誘導体、トリアゾール誘導体、シロール誘導体、ピリジン誘導体、ピリミジン誘導体及び８－キノリノール誘導体等の金属錯体等が挙げられる。 Conventionally, the electron transporting material used for the electron transporting layer (the electron transporting layer adjacent to the cathode side in the case of multiple layers) should have the function of transmitting electrons injected from the cathode to the light emitting layer. As the material thereof, any one can be selected and used from conventionally known compounds.
Examples thereof include metal complexes such as fluorene derivatives, carbazole derivatives, azacarbazole derivatives, oxadiazole derivatives, triazole derivatives, silole derivatives, pyridine derivatives, pyrimidine derivatives and 8-quinolinol derivatives.
　その他、メタルフリー若しくはメタルフタロシアニン、又はそれらの末端がアルキル基やスルホン酸基等で置換されているものも、電子輸送材料として好ましく用いることができる。 In addition, metal-free or metal phthalocyanines, or those whose terminals are substituted with alkyl groups, sulfonic acid groups, etc., can also be preferably used as electron transport materials.
　これらの中でも、カルバゾール誘導体、アザカルバゾール誘導体及びピリジン誘導体等が本発明では好ましく、アザカルバゾール誘導体であることがより好ましい。 Among these, carbazole derivatives, azacarbazole derivatives, pyridine derivatives and the like are preferred in the present invention, and azacarbazole derivatives are more preferred.
　電子輸送層は、上記電子輸送材料を、例えばスピンコート法、キャスト法、インクジェット印刷法を含む印刷法、ＬＢ法等の公知の方法により、薄膜化することにより形成することができ、好ましくは上記電子輸送材料、フッ化アルコール溶剤とを含有する塗布液を用いたウェット・プロセスにより形成することができる。 The electron transport layer can be formed by thinning the electron transport material by a known method such as a spin coating method, a casting method, a printing method including an inkjet printing method, or an LB method. It can be formed by a wet process using a coating liquid containing an electron transporting material and a fluorinated alcohol solvent.
　電子輸送層の層厚については特に制限はないが、通常は５ｎｍ～５μｍ程度の範囲内、好ましくは５～２００ｎｍの範囲内である。
　電子輸送層は、上記材料の一種又は二種以上からなる一層構造であっても良い。 The layer thickness of the electron-transporting layer is not particularly limited, but is usually in the range of about 5 nm to 5 μm, preferably in the range of 5 to 200 nm.
The electron-transporting layer may have a single-layer structure composed of one or more of the above materials.
　また、上記電子輸送材料の他に、不純物をゲスト材料としてドープしたｎ性の高い電子輸送層を用いることもできる。
　その例としては、特開平４－２９７０７６号公報、同１０－２７０１７２号公報、特開２０００－１９６１４０号公報、同２００１－１０２１７５号公報及びＪ．Ａｐｐｌ．Ｐｈｙｓ．，９５，５７７３（２００４）等に記載されたものが挙げられる。 In addition to the above electron transport materials, an electron transport layer having a high n property doped with an impurity as a guest material can also be used.
Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175 and J. Am. Appl. Phys. , 95, 5773 (2004).
　本発明における電子輸送層には、有機物のアルカリ金属塩を含有することが好ましい。
　有機物の種類としては特に制限はないが、ギ酸塩、酢酸塩、プロピオン酸、酪酸塩、吉草酸塩、カプロン酸塩、エナント酸塩、カプリル酸塩、シュウ酸塩、マロン酸塩、コハク酸塩、安息香酸塩、フタル酸塩、イソフタル酸塩、テレフタル酸塩、サリチル酸塩、ピルビン酸塩、乳酸塩、リンゴ酸塩、アジピン酸塩、メシル酸塩、トシル酸塩、ベンゼンスルホン酸塩が挙げられ、好ましくはギ酸塩、酢酸塩、プロピオン酸塩、酪酸塩、吉草酸塩、カプロン酸塩、エナント酸塩、カプリル酸塩、シュウ酸塩、マロン酸塩、コハク酸塩、安息香酸塩、より好ましくはギ酸塩、酢酸塩、プロピオン酸塩及び酪酸塩等の脂肪族カルボン酸のアルカリ金属塩が好ましく、脂肪族カルボン酸の炭素原子数が４以下であることが好ましい。
　最も好ましくは酢酸塩である。 The electron transport layer in the invention preferably contains an alkali metal salt of an organic substance.
Although there are no particular restrictions on the type of organic matter, formate, acetate, propionic acid, butyrate, valerate, caproate, enanthate, caprylate, oxalate, malonate, and succinate , benzoate, phthalate, isophthalate, terephthalate, salicylate, pyruvate, lactate, malate, adipate, mesylate, tosylate, benzenesulfonate. , preferably formate, acetate, propionate, butyrate, valerate, caproate, enanthate, caprylate, oxalate, malonate, succinate, benzoate, more preferably is preferably an alkali metal salt of an aliphatic carboxylic acid such as formate, acetate, propionate and butyrate, and preferably the aliphatic carboxylic acid has 4 or less carbon atoms.
Acetate is most preferred.
　有機物のアルカリ金属塩のアルカリ金属の種類としては特に制限はないが、Ｎａ、Ｋ、Ｃｓ及びＬｉが挙げられ、好ましくはＫ、Ｃｓ、更に好ましくはＣｓである。
　有機物のアルカリ金属塩としては、前記有機物とアルカリ金属の組み合わせが挙げられ、好ましくは、ギ酸Ｌｉ、ギ酸Ｋ、ギ酸Ｎａ、ギ酸Ｃｓ、酢酸Ｌｉ、酢酸Ｋ、酢酸Ｎａ、酢酸Ｃｓ、プロピオン酸Ｌｉ、プロピオン酸Ｎａ、プロピオン酸Ｋ、プロピオン酸Ｃｓ、シュウ酸Ｌｉ、シュウ酸Ｎａ、シュウ酸Ｋ、シュウ酸Ｃｓ、マロン酸Ｌｉ、マロン酸Ｎａ、マロン酸Ｋ、マロン酸Ｃｓ、コハク酸Ｌｉ、コハク酸Ｎａ、コハク酸Ｋ、コハク酸Ｃｓ、安息香酸Ｌｉ、安息香酸Ｎａ、安息香酸Ｋ及び安息香酸Ｃｓ、より好ましくは酢酸Ｌｉ、酢酸Ｋ、酢酸Ｎａ及び酢酸Ｃｓ、最も好ましくは酢酸Ｃｓである。 The type of alkali metal in the organic alkali metal salt is not particularly limited, but includes Na, K, Cs and Li, preferably K and Cs, more preferably Cs.
Examples of the alkali metal salts of organic substances include combinations of the above organic substances and alkali metals, preferably Li formate, K formate, Na formate, Cs formate, Li acetate, K acetate, Na acetate, Cs acetate, Li propionate, Sodium propionate, K propionate, Cs propionate, Li oxalate, Na oxalate, K oxalate, Cs oxalate, Li malonate, Na malonate, K malonate, Cs malonate, Li succinate, succinic acid Na, K succinate, Cs succinate, Li benzoate, Na benzoate, K benzoate and Cs benzoate, more preferably Li acetate, K acetate, Na acetate and Cs acetate, most preferably Cs acetate.
　これらドープ材の含有量は、添加する電子輸送層に対し、好ましくは１．５～３５質量％の範囲内であり、より好ましくは３～２５質量％の範囲内であり、最も好ましくは５～１５質量％の範囲内である。 The content of these dopants is preferably in the range of 1.5 to 35% by mass, more preferably in the range of 3 to 25% by mass, and most preferably in the range of 5 to It is within the range of 15% by mass.
　本発明の有機ＥＬ素子に用いられる公知の好ましい電子輸送材料の具体例としては、以下の文献に記載の化合物等が挙げられるが、本発明はこれらに限定されない。 Specific examples of known electron-transporting materials suitable for use in the organic EL device of the present invention include the compounds described in the following documents, but the present invention is not limited thereto.
　米国特許第６５２８１８７号明細書、米国特許第７２３０１０７号明細書、米国特許出願公開第２００５／００２５９９３号明細書、米国特許出願公開第２００４／００３６０７７号明細書、米国特許出願公開第２００９／０１１５３１６号明細書、米国特許出願公開第２００９／０１０１８７０号明細書、米国特許出願公開第２００９／０１７９５５４号明細書、国際公開第２００３／０６０９５６号、国際公開第２００８／１３２０８５号、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．７５，４（１９９９）、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．７９，４４９（２００１）、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．８１，１６２（２００２）、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．８１，１６２（２００２）、Ａｐｐｌ．Ｐｈｙｓ．Ｌｅｔｔ．７９，１５６（２００１）、米国特許第７９６４２９３号明細書、米国特許出願公開第２００９／０３０２０２号明細書、国際公開第２００４／０８０９７５号、国際公開第２００４／０６３１５９号、国際公開第２００５／０８５３８７号、国際公開第２００６／０６７９３１号、国際公開第２００７／０８６５５２号、国際公開第２００８／１１４６９０号、国際公開第２００９／０６９４４２号、国際公開第２００９／０６６７７９号、国際公開第２００９／０５４２５３号、国際公開第２０１１／０８６９３５号、国際公開第２０１０／１５０５９３号、国際公開第２０１０／０４７７０７号、欧州特許第２３１１８２６号明細書、特開２０１０－２５１６７５号公報、特開２００９－２０９１３３号公報、特開２００９－１２４１１４号公報、特開２００８－２７７８１０号公報、特開２００６－１５６４４５号公報、特開２００５－３４０１２２号公報、特開２００３－４５６６２号公報、特開２００３－３１３６７号公報、特開２００３－２８２２７０号公報及び国際公開第２０１２／１１５０３４号等に記載の化合物を挙げることができる。 US6528187, US7230107, US2005/0025993, US2004/0036077, US2009/0115316 , U.S. Patent Application Publication No. 2009/0101870, U.S. Patent Application Publication No. 2009/0179554, WO 2003/060956, WO 2008/132085, Appl. Phys. Lett. 75, 4 (1999), Appl. Phys. Lett. 79, 449 (2001), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 79, 156 (2001), US Pat. , International Publication No. 2006/067931, International Publication No. 2007/086552, International Publication No. 2008/114690, International Publication No. 2009/069442, International Publication No. 2009/066779, International Publication No. 2009/054253, International Publication No. 2011/086935, WO 2010/150593, WO 2010/047707, EP 2311826, JP 2010-251675, JP 2009-209133, JP 2009 -124114, JP 2008-277810, JP 2006-156445, JP 2005-340122, JP 2003-45662, JP 2003-31367, JP 2003-282270 No. 2012/115034 and the like.
　〔１．１．２．２〕正孔輸送層
　正孔輸送層は、電荷キャリアのうち正孔を輸送する機能を有する正孔輸送材料から構成されており、広い意味で正孔注入層、電子阻止層も正孔輸送層に含まれる。
　また、正孔輸送層は、単層又は複数層設けることができる。 [1.1.2.2] Hole-transport layer The hole-transport layer is composed of a hole-transport material having a function of transporting holes among charge carriers, and is broadly referred to as a hole-injection layer, an electron A blocking layer is also included in the hole transport layer.
Also, the hole transport layer can be provided as a single layer or a plurality of layers.
　正孔輸送材料としては、正孔の注入又は輸送、電子の障壁性のいずれかを有するものであり、有機物、無機物のいずれであっても良い。
　例えばトリアゾール誘導体、オキサジアゾール誘導体、イミダゾール誘導体、ポリアリールアルカン誘導体、ピラゾリン誘導体、ピラゾロン誘導体、フェニレンジアミン誘導体、アリールアミン誘導体、アミノ置換カルコン誘導体、オキサゾール誘導体、スチリルアントラセン誘導体、フルオレノン誘導体、ヒドラゾン誘導体、スチルベン誘導体、シラザン誘導体、アニリン系共重合体及び導電性高分子オリゴマー及びチオフェンオリゴマー等が挙げられる。 The hole transport material has either hole injection or transport or electron blocking properties, and may be either organic or inorganic.
For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbenes. derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers, thiophene oligomers, and the like.
　正孔輸送材料としては、上記のものを使用することができるが、ポルフィリン化合物、芳香族第３級アミン化合物及びスチリルアミン化合物を用いることができ、特に芳香族第３級アミン化合物を用いることが好ましい。 As the hole transport material, those mentioned above can be used, and porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds can be used, and aromatic tertiary amine compounds can be used in particular. preferable.
　芳香族第３級アミン化合物及びスチリルアミン化合物の代表例としては、Ｎ，Ｎ，Ｎ′，Ｎ′－テトラフェニル－４，４′－ジアミノフェニル、Ｎ，Ｎ′－ジフェニル－Ｎ，Ｎ′－ビス（３－メチルフェニル）－〔１，１′－ビフェニル〕－４，４′－ジアミン（略称：ＴＰＤ）、２，２－ビス（４－ジ－ｐ－トリルアミノフェニル）プロパン、１，１－ビス（４－ジ－ｐ－トリルアミノフェニル）シクロヘキサン、Ｎ，Ｎ，Ｎ′，Ｎ′－テトラ－ｐ－トリル－４，４′－ジアミノビフェニル、１，１－ビス（４－ジ－ｐ－トリルアミノフェニル）－４－フェニルシクロヘキサン、ビス（４－ジメチルアミノ－２－メチルフェニル）フェニルメタン、ビス（４－ジ－ｐ－トリルアミノフェニル）フェニルメタン、Ｎ，Ｎ′－ジフェニル－Ｎ，Ｎ′－ジ（４－メトキシフェニル）－４，４′－ジアミノビフェニル、Ｎ，Ｎ，Ｎ′，Ｎ′－テトラフェニル－４，４′－ジアミノジフェニルエーテル、４，４′－ビス（ジフェニルアミノ）クオードリフェニル、Ｎ，Ｎ，Ｎ－トリ（ｐ－トリル）アミン、４－（ジ－ｐ－トリルアミノ）－４′－〔４－（ジ－ｐ－トリルアミノ）スチリル〕スチルベン、４－Ｎ，Ｎ－ジフェニルアミノ－（２－ジフェニルビニル）ベンゼン、３－メトキシ－４′－Ｎ，Ｎ－ジフェニルアミノスチルベンゼン及びＮ－フェニルカルバゾール等が挙げられる。 Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl, N,N'-diphenyl-N,N'- Bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1 -bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl, 1,1-bis(4-di-p -tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-p-tolylaminophenyl)phenylmethane, N,N'-diphenyl-N, N'-di(4-methoxyphenyl)-4,4'-diaminobiphenyl, N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis(diphenylamino) quadriphenyl, N,N,N-tri(p-tolyl)amine, 4-(di-p-tolylamino)-4'-[4-(di-p-tolylamino)styryl]stilbene, 4-N,N -diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4'-N,N-diphenylaminostilbenzene and N-phenylcarbazole.
　さらには、米国特許第５０６１５６９号明細書に記載されている２個の縮合芳香族環を分子内に有するもの、例えば４，４′－ビス〔Ｎ－（１－ナフチル）－Ｎ－フェニルアミノ〕ビフェニル（略称：ＮＰＤ）、特開平４－３０８６８８号公報に記載されているトリフェニルアミンユニットが三つスターバースト型に連結された４，４′，４″－トリス〔Ｎ－（３－メチルフェニル）－Ｎ－フェニルアミノ〕トリフェニルアミン（略称：ＭＴＤＡＴＡ）等が挙げられる。 Furthermore, those having two condensed aromatic rings in the molecule described in US Pat. No. 5,061,569, such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino] Biphenyl (abbreviation: NPD), 4,4′,4″-tris[N-(3-methylphenyl )-N-phenylamino]triphenylamine (abbreviation: MTDATA) and the like.
　さらに、これらの材料を高分子鎖に導入した、又はこれらの材料を高分子の主鎖とした高分子材料を用いることもできる。
　また、ｐ型－Ｓｉ、ｐ型－ＳｉＣ等の無機化合物も正孔注入材料、正孔輸送材料として使用することができる。 Furthermore, polymer materials in which these materials are introduced into the polymer chain or these materials are used as the main chain of the polymer can also be used.
Inorganic compounds such as p-type-Si and p-type-SiC can also be used as hole-injecting materials and hole-transporting materials.
　また、特開平１１－２５１０６７号公報、Ｊ．Ｈｕａｎｇ　ｅｔ．ａｌ．，Ａｐｐｌｉｅｄ　Ｐｈｙｓｉｃｓ　Ｌｅｔｔｅｒｓ，８０（２００２），ｐ．１３９に記載されているような、いわゆるｐ型正孔輸送材料を用いることもできる。
　本発明においては、より高効率の発光素子が得られる観点から、これらの材料を用いることが好ましい。 Also, Japanese Patent Application Laid-Open No. 11-251067, J. Am. Huang et. al. , Applied Physics Letters, 80 (2002), p. 139, so-called p-type hole transport materials can also be used.
In the present invention, these materials are preferably used from the viewpoint of obtaining a light-emitting device with higher efficiency.
　正孔輸送層は、上記正孔輸送材料を、例えば真空蒸着法、スピンコート法、キャスト法、インクジェット印刷法を含む印刷法及びＬＢ法（ラングミュア・ブロジェット、Ｌａｎｇｍｕｉｒ　Ｂｌｏｄｇｅｔｔ法）等の公知の方法により、薄膜化することにより形成することができる。
　正孔輸送層の層厚については特に制限はないが、通常は５ｎｍ～５μｍ程度の範囲内、好ましくは５～２００ｎｍの範囲内である。
　この正孔輸送層は、上記材料の一種又は二種以上からなる一層構造であっても良い。 The hole-transporting layer is formed by applying the above-mentioned hole-transporting material by a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, a printing method including an inkjet printing method, and an LB method (Langmuir Blodgett method). can be formed by thinning.
The layer thickness of the hole-transporting layer is not particularly limited, but is usually in the range of about 5 nm to 5 μm, preferably in the range of 5 to 200 nm.
The hole transport layer may have a single-layer structure composed of one or more of the above materials.
　また、正孔輸送層の材料に不純物をドープすることにより、ｐ性を高くすることもできる。
　その例としては、特開平４－２９７０７６号公報、特開２０００－１９６１４０号公報、同２００１－１０２１７５号公報及びＪ．Ａｐｐｌ．Ｐｈｙｓ．，９５，５７７３（２００４）等に記載されたものが挙げられる。 Further, the p-property can be increased by doping the material of the hole transport layer with impurities.
Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175 and J. Am. Appl. Phys. , 95, 5773 (2004).
　このように、正孔輸送層のｐ性を高くすると、より低消費電力の素子を作製することができるため好ましい。 By increasing the p-property of the hole-transporting layer in this way, it is possible to manufacture an element with lower power consumption, which is preferable.
　〔１．１．３〕電子阻止層
　電子阻止層とは、広い意味では、正孔輸送層の機能を有する。
　電子阻止層は、正孔を輸送する機能を有しつつ、電子を輸送する能力が著しく小さい材料からなり、正孔を輸送しつつ電子を阻止することで電子と正孔の再結合確率を向上させることができる。
　また、正孔輸送層の構成を必要に応じて電子阻止層として用いることができる。正孔阻止層の層厚としては、好ましくは３～１００ｎｍの範囲内であり、更に好ましくは５～３０ｎｍの範囲内である。 [1.1.3] Electron blocking layer The electron blocking layer has the function of a hole transport layer in a broad sense.
The electron-blocking layer is made of a material that has the function of transporting holes but has a significantly low ability to transport electrons. By blocking electrons while transporting holes, the probability of recombination between electrons and holes is improved. can be made
Moreover, the structure of a hole transport layer can be used as an electron blocking layer as needed. The layer thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.
　〔１．１．４〕電荷キャリア注入層：電荷注入層
　「電荷キャリア注入層（以下において「電荷注入層」ともいう。）」とは、電荷キャリアすなわち電子又は正孔を注入する機能を有する化合物を含有する層をいう。
　以下においては、電荷キャリア注入層（「電荷注入層」）を「正孔注入層」と「正孔注入層」に分けて説明する。 [1.1.4] Charge carrier injection layer: charge injection layer A “charge carrier injection layer (hereinafter also referred to as a “charge injection layer”)” is a compound having the function of injecting charge carriers, that is, electrons or holes. refers to a layer containing
In the following description, the charge carrier injection layer (“charge injection layer”) is divided into “hole injection layer” and “hole injection layer”.
　電荷注入層（正孔注入層及び電子注入層）とは、駆動電圧低下や発光輝度向上のために、電極と発光層の間に設けられる電荷キャリアすなわち電子又は正孔の注入層のことで、「有機ＥＬ素子とその工業化最前線（１９９８年１１月３０日エヌ・ティー・エス社発行）」の第２編第２章「電極材料」（１２３～１６６頁）にその詳細が記載されており、正孔注入層と電子注入層とがある。 The charge injection layer (hole injection layer and electron injection layer) is a layer for injecting charge carriers, that is, electrons or holes, provided between the electrode and the light emitting layer in order to reduce the driving voltage and improve the luminance of the emitted light. The details are described in "Organic EL element and its industrial front" (published by NTS on November 30, 1998), Part 2, Chapter 2, "Electrode materials" (pp. 123-166). , a hole-injection layer and an electron-injection layer.
　注入層は、必要に応じて設けることができる。
　正孔注入層であれば、アノードと発光層又は正孔輸送層との間、電子注入層であればカソードと発光層又は電子輸送層との間に存在させても良い。 An injection layer can be provided as needed.
A hole-injecting layer may be present between the anode and the light-emitting layer or the hole-transporting layer, and an electron-injecting layer may be present between the cathode and the light-emitting layer or the electron-transporting layer.
　正孔注入層は、特開平９－４５４７９号公報、同９－２６００６２号公報、同８－２８８０６９号公報等にその詳細が記載されており、具体例として、銅フタロシアニンに代表されるフタロシアニン層、酸化バナジウムに代表される酸化物層、アモルファスカーボン層、ポリアニリン（エメラルディン）やポリチオフェン等の導電性高分子を用いた高分子層等が挙げられる。 Details of the hole injection layer are described in JP-A-9-45479, JP-A-9-260062, and JP-A-8-288069. Examples include an oxide layer represented by vanadium oxide, an amorphous carbon layer, and a polymer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.
　電子注入層は、特開平６－３２５８７１号公報、同９－１７５７４号公報、同１０－７４５８６号公報等にその詳細が記載されており、具体的にはストロンチウムやアルミニウム等に代表される金属層、フッ化カリウムに代表されるアルカリ金属ハライド層、フッ化マグネシウムに代表されるアルカリ土類金属化合物層、酸化モリブデンに代表される酸化物層等が挙げられる。
　本発明においては、電子注入層はごく薄い膜であることが望ましく、構成材料にもよるが、その層厚は１ｎｍ～１０μｍの範囲内が好ましい。 Details of the electron injection layer are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, etc. Specifically, a metal layer represented by strontium, aluminum, etc. , an alkali metal halide layer typified by potassium fluoride, an alkaline earth metal compound layer typified by magnesium fluoride, an oxide layer typified by molybdenum oxide, and the like.
In the present invention, the electron injection layer is desirably a very thin film, and although it depends on the constituent materials, the layer thickness is preferably in the range of 1 nm to 10 μm.
　〔１．１．５〕陽極
　有機ＥＬ素子における陽極としては、仕事関数の大きい（４ｅＶ以上）金属、合金、電気伝導性化合物及びこれらの混合物を電極物質とするものが好ましく用いられる。
　このような電極物質の具体例としてはＡｕ等の金属、ＣｕＩ、インジウムチンオキシド（ＩＴＯ）、ＳｎＯ２、ＺｎＯ及びＩＺＯ等の導電性透明材料が挙げられる。
　また、ＩＤＩＸＯ（Ｉｎ２Ｏ３－ＺｎＯ）等非晶質で透明導電膜を作製可能な材料を用いても良い。
　陽極はこれらの電極物質を蒸着やスパッタリング等の方法により、薄膜を形成させ、フォトリソグラフィー法で所望の形状のパターンを形成しても良く、パターン精度をあまり必要としない場合は（１００μｍ以上程度）、上記電極物質の蒸着やスパッタリング時に所望の形状のマスクを介してパターンを形成しても良い。
　また、有機導電性化合物のように塗布可能な物質を用いる場合には、印刷方式、コーティング方式など湿式製膜法を用いることもできる。
　この陽極より発光を取り出す場合には、透過率を１０％より大きくすることが望ましく、また陽極としてのシート抵抗は数百Ω／□以下が好ましい。
　さらに、膜厚は材料にもよるが、通常１０～１０００ｎｍの範囲内、好ましくは１０～２００ｎｍの範囲内で選ばれる。 [1.1.5] Anode As an anode in an organic EL element, an electrode material having a large work function (4 eV or more), an alloy, an electrically conductive compound, or a mixture thereof is preferably used.
Specific examples of such electrode materials include metals such as Au, conductive transparent materials such as CuI, indium tin oxide (ITO), SnO 2 , ZnO and IZO.
A material such as IDIXO (In 2 O 3 —ZnO) that is amorphous and capable of forming a transparent conductive film may also be used.
The anode may be formed by forming a thin film of these electrode substances by a method such as vapor deposition or sputtering, and forming a pattern of a desired shape by photolithography. A pattern may be formed through a mask having a desired shape during vapor deposition or sputtering of the electrode material.
In the case of using a coatable substance such as an organic conductive compound, a wet film-forming method such as a printing method or a coating method may be used.
When emitting light from the anode, the transmittance is desirably greater than 10%, and the sheet resistance of the anode is preferably several hundred Ω/□ or less.
Furthermore, although the film thickness depends on the material, it is usually selected within the range of 10 to 1000 nm, preferably within the range of 10 to 200 nm.
　〔１．１．６〕陰極
　一方、陰極としては、陽極と同等の仕事関数である導電性透明材料、又は、仕事関数の小さい（４ｅＶ以下）金属（電子注入性金属と称する。）、合金、電気伝導性化合物及びこれらの混合物を電極物質とするものが用いられる。
　このような電極物質の具体例としては、ナトリウム、ナトリウム－カリウム合金、マグネシウム、リチウム、マグネシウム／銅混合物、マグネシウム／銀混合物、マグネシウム／アルミニウム混合物、マグネシウム／インジウム混合物、アルミニウム／酸化アルミニウム（Ａｌ２Ｏ３）混合物、銀、インジウム、リチウム／アルミニウム混合物及び希土類金属等が挙げられる。 [1.1.6] Cathode On the other hand, as the cathode, a conductive transparent material having a work function equivalent to that of the anode, or a metal having a small work function (4 eV or less) (referred to as an electron-injecting metal), an alloy, Electroconductive compounds and mixtures thereof are used as electrode materials.
Specific examples of such electrode materials include sodium, sodium-potassium alloys, magnesium, lithium, magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indium mixtures, aluminum/aluminum oxide (Al 2 O 3 ) mixtures, silver, indium, lithium/aluminum mixtures and rare earth metals;
　これらの中で、電子注入性及び酸化等に対する耐久性の点から、電子注入性金属とこれより仕事関数の値が大きく安定な金属である第二金属との混合物、例えばマグネシウム／銀混合物、マグネシウム／アルミニウム混合物、マグネシウム／インジウム混合物、アルミニウム／酸化アルミニウム（Ａｌ２Ｏ３）混合物、リチウム／アルミニウム混合物、銀及びアルミニウム等が好適である。
　陰極はこれらの電極物質を蒸着、スパッタリング、貼合等の方法により薄膜を形成させることにより、作製することができる。
　また、陰極としてのシート抵抗は数百Ω／□以下が好ましく、膜厚は通常１０ｎｍ～５μｍの範囲内、好ましくは５０～２００ｎｍの範囲内で選ばれる。
　なお、発光した光を透過させるため、有機ＥＬ素子の陽極又は陰極のいずれか一方が、透明又は半透明であれば発光輝度が向上し好都合である。 Among them, from the viewpoint of electron injection properties and durability against oxidation, etc., a mixture of an electron injection metal and a second metal that has a higher work function and is more stable, such as a magnesium/silver mixture, magnesium /aluminum mixtures, magnesium/indium mixtures, aluminum/aluminum oxide ( Al2O3 ) mixtures, lithium/aluminum mixtures, silver and aluminum, etc. are suitable.
The cathode can be produced by forming a thin film of these electrode substances by a method such as vapor deposition, sputtering, or lamination.
Moreover, the sheet resistance of the cathode is preferably several hundred Ω/□ or less, and the film thickness is usually selected within the range of 10 nm to 5 μm, preferably within the range of 50 to 200 nm.
In order to transmit the emitted light, it is convenient if either the anode or the cathode of the organic EL element is transparent or semi-transparent because the luminance of the emitted light is improved.
　また、陰極に上記金属を１～２０ｎｍの範囲内の膜厚で作製した後に、陽極の説明で挙げた導電性透明材料をその上に作製することで、透明又は半透明の陰極を作製することができ、これを応用することで陽極と陰極の両方が透過性を有する素子を作製することができる。 Alternatively, a transparent or translucent cathode can be produced by forming the above-mentioned metal on the cathode with a film thickness in the range of 1 to 20 nm and then forming thereon the conductive transparent material mentioned in the explanation of the anode. By applying this, it is possible to fabricate a device in which both the anode and the cathode are transparent.
　〔１．２〕非発光画像表示部
　本発明の有機ＥＬ素子は、「発光画像表示部」と「非発光画像表示部」で構成される画像表示部を有するが、当該非発光画像表示部は、当該画像表示部を構成する「発光画像表示部」以外の部位である。
　すなわち、本発明の有機ＥＬ素子は、画像表示部の中に含まれている複数の非発光画像表示部の間に、発光画素がドット状に配置された発光画像表示部を有する形態であることが好ましい。
　なお、当該非発光画像表示部は、非発光性の部位であることから、電気的な絶縁性層として機能する隔壁（以下、「バンク」ともい。）や発光材を含有するインクを浸透させていない絶縁性インク受容層部分を隔壁（絶縁性層）として機能させる形態であることが好ましい。 [1.2] Non-luminous image display part The organic EL element of the present invention has an image display part composed of a "luminous image display part" and a "non-luminous image display part". , a portion other than the “luminescent image display portion” that constitutes the image display portion.
That is, the organic EL element of the present invention has a form in which a luminescence image display portion in which luminescence pixels are arranged in dots is provided between a plurality of non-luminescence image display portions included in the image display portion. is preferred.
Since the non-light-emitting image display portion is a non-light-emitting portion, partition walls (hereinafter also referred to as "banks") functioning as an electrically insulating layer and ink containing a light-emitting material are permeated. It is preferable that the non-insulating ink-receiving layer portion functions as a partition wall (insulating layer).
　本発明でいう「絶縁性」とは、電子や正孔が移動しにくい、すなわち、電気を通しにくい性質をいい、電気抵抗率が比較的高い、例えば抵抗率が１０５Ω・ｍ超である性質をいう。
　換言すると、導電率が１０－５Ｓ／ｍ未満である性質をいう。電気抵抗率は、ニ重リング電極を用いた定電圧印加・漏洩電流測定法によりＪＩＳ－Ｋ－６９１１に準拠した条件で得られた値を用いる。 The term “insulating” as used in the present invention refers to a property in which electrons and holes are difficult to move, that is, it is difficult to conduct electricity. say nature.
In other words, it refers to the property that the electrical conductivity is less than 10 −5 S/m. As the electric resistivity, a value obtained under conditions conforming to JIS-K-6911 by a constant voltage application/leakage current measurement method using a double ring electrode is used.
　本発明の有機ＥＬ素子の実施形態としては、事前にバンクを形成しても良いし、又は、絶縁性層を一様に形成した後に、インクジェットの打ち分けによって発光層を形成し、自発的にバンクを形成しても良いが、前者の方法が好ましい。 As an embodiment of the organic EL element of the present invention, a bank may be formed in advance, or after forming an insulating layer uniformly, a light-emitting layer is formed by ink-jetting separately, and spontaneously Banks may be formed, but the former method is preferred.
　本発明の有機ＥＬ素子の実施形態としては、基板表面に絶縁性層としてバンクを形成することが好ましい一形態である。
　一般的に、バンクは、基板表面における有機ＥＬ素子を構成する材料を含む液等の被塗布領域の周縁に形成されており、塗布された有機ＥＬ素子を構成する材料を含む液等の被塗付領域外への流出を防止する役割及び電気的な絶縁性を有する役割がある。 As an embodiment of the organic EL device of the present invention, it is a preferred form to form a bank as an insulating layer on the substrate surface.
In general, the bank is formed on the periphery of the area to be coated with the liquid containing the material constituting the organic EL element on the substrate surface, and the applied liquid containing the material constituting the organic EL element is applied. It has the role of preventing outflow to the outside of the attached area and the role of providing electrical insulation.
　図３は、バンクを有する基板の一例を示す断面図である。
　バンク２によって区切られた基板１表面の領域はバンクの凹部２ａであり、バンクの表面にはバンクの凸部２ｂがある。
　前記凹部２ａに本発明に係る発光画像表示部を形成する。 FIG. 3 is a cross-sectional view showing an example of a substrate having banks.
The regions of the surface of the substrate 1 delimited by the banks 2 are bank depressions 2a, and the bank surfaces are bank projections 2b.
A light-emitting image display portion according to the present invention is formed in the concave portion 2a.
　バンクの高さは、塗布されたインク等の流出を防ぐことが可能であれば特に限定されないが、１．１～２．５μｍの範囲内であることが好ましい。
　さらに好ましい範囲は、１．５～２．５μｍの範囲内である。 The height of the bank is not particularly limited as long as it is possible to prevent the applied ink from flowing out, but it is preferably in the range of 1.1 to 2.5 μm.
A more preferable range is 1.5 to 2.5 μm.
　また、バンクの形状は、図３で例示した台形の他、目的効果に応じて様々な形状のバンクを適用することができる。 In addition, as for the shape of the bank, in addition to the trapezoid illustrated in FIG. 3, banks of various shapes can be applied according to the intended effect.
　〔１．２．１〕絶縁性材料
　本発明に係る絶縁性層（バンク）の材料には、公知のものを用いることができるが、ポリシロキサン骨格に少なくとも一種のアルキル基以外の有機基を有する有機無機ハイブリッドポリマーを含有することが、好ましい。
　ポリシロキサン構造に少なくとも一種のアルキル基以外の有機基を有することにより、耐溶媒性と耐剥離性に優れた発光画像表示部とすることが可能となる。 [1.2.1] Insulating Material A known material can be used as the material of the insulating layer (bank) according to the present invention, but the polysiloxane skeleton has at least one organic group other than an alkyl group. It is preferable to contain an organic-inorganic hybrid polymer.
By having at least one organic group other than an alkyl group in the polysiloxane structure, it is possible to obtain a light-emitting image display portion having excellent solvent resistance and peeling resistance.
　（有機無機ハイブリッドポリマー構造）
　本発明に用いられる有機無機ハイブリッドポリマーのアルキル基以外の有機基としては、公知の置換基を特に制限なく使用可能であり、例えばアリール基、アラアルキル基、シクロアルキル基、アミノ基、イミノ基、シアノ基、ニトロ基、ニトロソ基、アゾ基、ジアゾ基、アジ基、カルボニル基、フェニル基、ヒドロキシ基、ペルオキシ基、アシル基、アセチル基、アルデヒド基、カルボキシ基、アミド基、イミド基、エステル基、オキシム基、チオール基、スルホ基、ウレア基、イソニトリル基、アレン基、アクリロイル基、メタクリロイル基、エポキシ基、オキセタン基及びイソシアネート基等を用いることができる。
　上記の中では、アクリロイル基、エポキシ基又はイソシアネート基が好ましい。
　中でも、アクリロイル基が特に好ましい。 (Organic-inorganic hybrid polymer structure)
As the organic group other than the alkyl group of the organic-inorganic hybrid polymer used in the present invention, known substituents can be used without particular limitation. group, nitro group, nitroso group, azo group, diazo group, azide group, carbonyl group, phenyl group, hydroxy group, peroxy group, acyl group, acetyl group, aldehyde group, carboxy group, amide group, imide group, ester group, Oxime groups, thiol groups, sulfo groups, urea groups, isonitrile groups, allene groups, acryloyl groups, methacryloyl groups, epoxy groups, oxetane groups, isocyanate groups, and the like can be used.
Among the above, an acryloyl group, an epoxy group, or an isocyanate group is preferred.
Among them, an acryloyl group is particularly preferred.
　（ポリシロキサン構造）
　ポリシロキサン構造としては、例えばＳｉ－Ｏ－Ｓｉ結合を有するポリシロキサン（ポリシルセスキオキサンを含む）を挙げることができる。
　ポリシロキサンとしては、具体的には、一般構造単位としての〔Ｒ３ＳｉＯ１／２〕、〔Ｒ２ＳｉＯ〕、〔ＲＳｉＯ３／２〕及び〔ＳｉＯ２〕を含むことができる。
　ここで、Ｒは、水素原子、炭素数１～２０のアルキル基（例えばメチル基（Ｍｅ）、エチル基、プロピル基等）、アリール基（例えばフェニル基（Ｐｈ）等）、不飽和アルキル基（例えばビニル基等）からなる群より独立して選択される。
　特定のポリシロキサン構造の例としては、〔ＰｈＳｉＯ３／２〕、〔ＭｅＳｉＯ３／２〕、〔ＨＳｉＯ３／２〕、〔ＭｅＰｈＳｉＯ〕、〔Ｐｈ２ＳｉＯ〕、〔ＰｈＶｉＳｉＯ〕、〔ＶｉＳｉＯ３／２〕（Ｖｉはビニル基を表す。）、〔ＭｅＨＳｉＯ〕、〔ＭｅＶｉＳｉＯ〕、〔Ｍｅ２ＳｉＯ〕及び〔Ｍｅ３ＳｉＯ１／２〕等が挙げられる。
　また、ポリシロキサンの混合物やコポリマーも使用可能である。 (polysiloxane structure)
Examples of polysiloxane structures include polysiloxanes (including polysilsesquioxanes) having Si—O—Si bonds.
Specifically, polysiloxane can include [R 3 SiO 1/2 ], [R 2 SiO], [RSiO 3/2 ] and [SiO 2 ] as general structural units.
Here, R is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (eg, methyl group (Me), ethyl group, propyl group, etc.), an aryl group (eg, phenyl group (Ph), etc.), unsaturated alkyl group ( are independently selected from the group consisting of, for example, vinyl groups, etc.).
Examples of specific polysiloxane structures include [PhSiO 3/2 ], [MeSiO 3/2 ], [HSiO 3/2 ], [MePhSiO], [Ph 2 SiO], [PhViSiO], [ViSiO 3/2 ] (Vi represents a vinyl group), [MeHSiO], [MeViSiO], [Me 2 SiO] and [Me 3 SiO 1/2 ].
Mixtures and copolymers of polysiloxanes can also be used.
　〔１．２．２〕バインダー樹脂
　絶縁性層には、本発明に用いられる有機無機ハイブリッドポリマーの他に、本発明の効果を損なわない範囲内でバインダー樹脂を用いることができる。
　バインダー樹脂としては、例えばセルロースジアセテート、セルローストリアセテート、セルロースアセテートブチレート、セルロースアセテートフタレート、セルロースナイトレート等のセルロース誘導体、ポリ酢酸ビニル、ポリスチレン、ポリカーボネート、ポリブチレンテレフタレート、コポリブチレン／テレ／イソフタレート等のポリエステル、ポリビニルアルコール、ポリビニルホルマール、ポリビニルアセタール、ポリビニルブチラール、ポリビニルベンザール等のポリビニルアルコール誘導体、ノルボルネン化合物を含有するノルボルネン系ポリマー、ポリメチルメタクリレート、ポリエチルメタクリレート、ポリプロピルチルメタクリレート、ポリブチルメタクリレート、ポリメチルアクリレート等のアクリル樹脂又はアクリル樹脂とその他樹脂との共重合体を用いることができるが、特にこれら例示する樹脂材料に限定されるものではない。
　この中では、セルロース誘導体、アクリル樹脂が好ましく、アクリル樹脂が最も好ましく用いられる。 [1.2.2] Binder Resin In addition to the organic-inorganic hybrid polymer used in the present invention, a binder resin may be used in the insulating layer within a range that does not impair the effects of the present invention.
Examples of binder resins include cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate; Polyvinyl alcohol derivatives such as polyester, polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polyvinyl benzal, norbornene-based polymers containing norbornene compounds, polymethyl methacrylate, polyethyl methacrylate, polypropyltyl methacrylate, polybutyl methacrylate, polymethyl Acrylic resins such as acrylates or copolymers of acrylic resins and other resins can be used, but the material is not particularly limited to these exemplified resin materials.
Among these, cellulose derivatives and acrylic resins are preferred, and acrylic resins are most preferred.
　（絶縁性金属酸化物）
　絶縁性層の材料としては、バインダー樹脂に絶縁性金属酸化物を含有することも好ましい。 (insulating metal oxide)
As a material for the insulating layer, it is also preferable to contain an insulating metal oxide in the binder resin.
　絶縁性金属酸化物としては、特に制限されないが、化学的安定性、物理的安定性という観点から、アルミナ、ジルコニア、チタニア、シリカ、マグネシア又はニオブが好ましい。
　具体的には、酸化チタン、酸化ジルコニウム、酸化タンタル、酸化ジルコニウムと酸化シリコンとの固溶体、酸化シリコン、酸化二アルミニウム、酸化亜鉛、酸化マグネシウム、酸化ニオブ、酸化ビスマス、酸化銅、酸化スズ、酸化ハフニウム、又はこれら金属酸化物の水和物、さらには、チタン酸バリウム、ジルコニウム酸バリウム、ニオブ酸カリウム、ニオブ酸ナトリウム、チタン酸カルシウム、タンタル酸ストロンチウム、チタン酸ビスマス、チタン酸ビスマスナトリウム、又はこれらのうち少なくとも一種を組成に含む絶縁性固溶体を例示することができる。 Although the insulating metal oxide is not particularly limited, alumina, zirconia, titania, silica, magnesia, or niobium is preferable from the viewpoint of chemical stability and physical stability.
Specifically, titanium oxide, zirconium oxide, tantalum oxide, solid solution of zirconium oxide and silicon oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, niobium oxide, bismuth oxide, copper oxide, tin oxide, hafnium oxide. or hydrates of these metal oxides, barium titanate, barium zirconate, potassium niobate, sodium niobate, calcium titanate, strontium tantalate, bismuth titanate, bismuth sodium titanate, or these An insulating solid solution containing at least one of them in its composition can be exemplified.
　中でも、好ましくは比誘電率１００以上の金属酸化物が挙げられ、この例としては、ルチル型の酸化チタン（ＴｉＯ２）、酸化ジルコニウム（ＺｒＯ）、五酸化ニオブ（Ｎｂ２Ｏ３）、チタン酸バリウム（ＢａＴｉＯ３）、チタン酸ストロンチウム（ＳｒＴｉＯ３）、チタン酸鉛（ＰｂＴｉＯ３）や、チタン酸ジルコン酸バリウム（ＢａＴｉ０．５Ｚｒ０．５Ｏ３）、チタン酸ジルコン酸鉛（ＰｂＴｉ０．５Ｚｒ０．５Ｏ３）などの組成式ＭＴｉ１－ｘＺｒｘＯ３（Ｍは二価の金属元素、ｘは０以上１未満）で表される絶縁性金属酸化物、又はこれらの水和物、さらには、これらのうち少なくとも一種類を組成に含む絶縁性固溶体が挙げられる。 Among them, metal oxides having a dielectric constant of 100 or more are preferable, and examples thereof include rutile-type titanium oxide (TiO 2 ), zirconium oxide (ZrO), niobium pentoxide (Nb 2 O 3 ), and titanic acid. Barium (BaTiO 3 ), strontium titanate (SrTiO 3 ), lead titanate (PbTiO 3 ), barium zirconate titanate (BaTi 0.5 Zr 0.5 O 3 ), lead zirconate titanate (PbTi 0.5 ) . 5 Zr 0.5 O 3 ) or the like , or water thereof hydrates, and insulating solid solutions containing at least one of these in the composition.
　絶縁性層は、あらかじめ非画像部にパターニングをしておいても良いし、絶縁層に対して可溶な機能材を含むインクを打ち込んで電流の流れる道筋（導電パス）を作製する方法を用いてもよい。
　パターニングをしておく場合、例えば絶縁性層は以下のような手法によって形成される。 The insulating layer may be patterned in advance on the non-image portion, or a method of forming a current flow path (conductive path) by injecting ink containing a soluble functional material into the insulating layer is used. may
In the case of patterning, for example, the insulating layer is formed by the following method.
　基板として、０．５ｍｍのガラス基板（コーニング社製　ＥａｇｌｅＸＧ）をアルカリ洗浄し、次に、酸化チタンを３０質量％含有する感光性ポリイミド（メルク社製）を、スピンコート法で塗布し、６０℃で１２０秒間のプリベークを行う。
　次に、フォト工程でパターン露光し、水酸化テトラメチルアンモニウム（略称：ＴＭＡＨ）で現像、純水によりリンスすることで、開口部を有するバンクを形成する。 As a substrate, a 0.5 mm glass substrate (Eagle XG manufactured by Corning) was washed with an alkali, and then a photosensitive polyimide containing 30% by mass of titanium oxide (manufactured by Merck) was applied by spin coating, and the temperature was kept at 60°C. is pre-baked for 120 seconds.
Next, pattern exposure is performed by a photo process, development is performed with tetramethylammonium hydroxide (abbreviation: TMAH), and rinsing is performed with pure water to form banks having openings.
　〔１．１．３〕極性フッ化溶媒
　絶縁性層の形成には極性フッ化溶媒が用いられることが好ましい。
　また、後述する電子輸送層の形成にも極性フッ化溶媒が用いられることが好ましい。 [1.1.3] Polar fluorinated solvent A polar fluorinated solvent is preferably used for forming the insulating layer.
A polar fluorinated solvent is also preferably used for forming an electron transport layer, which will be described later.
　ここで、極性フッ化溶媒とは、溶媒分子中にフッ素原子を含み、比誘電率が３以上、かつ、２５℃における水への溶解度が５ｇ／Ｌ以上である溶媒をいう。 Here, the polar fluorinated solvent refers to a solvent that contains fluorine atoms in the solvent molecule, has a dielectric constant of 3 or more, and has a solubility in water of 5 g/L or more at 25°C.
　極性フッ化溶媒の沸点としては、５０～２００℃の範囲内が好ましい。
　５０℃以上とすることで、塗布膜乾燥時の蒸発熱によるムラの発生をより確実に抑制できる。
　２００℃以下とすることで、速やかに溶媒を乾燥させることができ、形成される層内の溶媒含有量が低減するため層内の結晶成長をより確実に抑制できるとともに、溶媒の抜け道が粗とならないため密度が向上し電流効率を上昇させることができる。
　より好ましくは、７０～１５０℃の範囲内である。 The boiling point of the polar fluorinated solvent is preferably within the range of 50 to 200°C.
By setting the temperature to 50° C. or higher, it is possible to more reliably suppress the occurrence of unevenness due to heat of evaporation during drying of the coating film.
By setting the temperature to 200° C. or less, the solvent can be dried quickly, the solvent content in the formed layer is reduced, so that the crystal growth in the layer can be suppressed more reliably, and the solvent escape route is rough. Therefore, the density is improved and the current efficiency can be increased.
More preferably, it is within the range of 70 to 150°C.
　極性フッ化溶媒の水分含有量は、極微量であっても発光のクエンチャーとなるため少ない程良く、１００ｐｐｍ以下が好ましく、２０ｐｐｍ以下であることが更に好ましい。 The water content of the polar fluorinated solvent is preferably as low as possible because even a very small amount of water is a quencher of light emission, preferably 100 ppm or less, more preferably 20 ppm or less.
　また、極性フッ化溶媒中の水分以外の不純物含有量も同様に、極微量であっても発光のクエンチャーとなったり、気泡や乾燥後の膜質低下要因となったりするため少ない程良く、１００ｐｐｍ以下が好ましく、２０ｐｐｍ以下であることが更に好ましい。
　水分以外の不純物としては、酸素や、窒素、アルゴン及び二酸化炭素等の不活性ガス、調製及び精製時に使用される触媒、吸着材及び器具等から持ち込まれる無機化合物又は金属等が挙げられる。 Similarly, the content of impurities other than water in the polar fluorinated solvent is as low as 100 ppm, because even a very small amount can become a quencher of light emission, cause air bubbles, or cause deterioration of the film quality after drying. The following is preferable, and 20 ppm or less is more preferable.
Impurities other than water include oxygen, inert gases such as nitrogen, argon and carbon dioxide, and inorganic compounds or metals brought in from catalysts, adsorbents and equipment used during preparation and purification.
　極性フッ化溶媒としては、例えばフッ化アルコール、フッ化アクリレート、フッ化メタクリレート、フッ化エステル、フッ化エーテル又はフッ化ヒドロキシアルキルベンゼン、フッ化アミンが好ましく、フッ化アルコール、フッ化エステル又はフッ化エーテルがより好ましく、溶解性と乾燥性の観点からフッ化アルコールが更に好ましい。 Examples of the polar fluorinated solvent include fluorinated alcohols, fluorinated acrylates, fluorinated methacrylates, fluorinated esters, fluorinated ethers, fluorinated hydroxyalkylbenzenes, and fluorinated amines, and fluorinated alcohols, fluorinated esters, and fluorinated ethers. is more preferred, and fluorinated alcohol is even more preferred from the viewpoint of solubility and drying property.
　また、フッ化アルコールの炭素原子数は、沸点及び材料の可溶性の観点から、炭素原子数３～５であることが好ましい。 In addition, the number of carbon atoms in the fluorinated alcohol is preferably 3 to 5 from the viewpoint of the boiling point and the solubility of the material.
　フッ素置換位置としては、例えばアルコールであれば水素の位置が挙げられ、フッ素化率としては、層材料の溶解性を損なわない程度であれば良く、下層材料を溶出させない程度にフッ素化されていることが望ましい。 The fluorine-substituted position is, for example, the position of hydrogen in the case of alcohol, and the fluorination rate is sufficient as long as it does not impair the solubility of the layer material, and is fluorinated to the extent that the lower layer material is not eluted. is desirable.
　フッ化アルコールとしては、例えば１Ｈ，１Ｈ－ペンタフルオロプロパノール、６－（パーフルオロエチル）ヘキサノール、１Ｈ，１Ｈ－ヘプタフルオロブタノール、２－（パーフルオロブチル）エタノール（ＦＢＥＯ）、３－（パーフルオロブチル）プロパノール、６－（パーフルオロブチル）ヘキサノール、２－パーフルオロプロポキシ－２，３，３，３－テトラフルオロプロパノール、２－（パーフルオロヘキシル）エタノール、３－（パーフルオロヘキシル）プロパノール、６－（パーフルオロヘキシル）ヘキサノール、１Ｈ，１Ｈ－（パーフルオロヘキシル）ヘキサノール、６－（パーフルオロ－１－メチルエチル）ヘキサノール、１Ｈ，１Ｈ，３Ｈ－テトラフルオロプロパノール（ＴＦＰＯ）、１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンタノール（ＯＦＡＯ）、１Ｈ，１Ｈ，７Ｈ－ドデカフルオロヘプタノール（ＤＦＨＯ）、２Ｈ－ヘキサフルオロ－２－プロパノール、１Ｈ，１Ｈ，３Ｈ－ヘキサフルオロブタノール（ＨＦＢＯ）、２，２，３，３，４，４，５，５－オクタフルオロ－１，６－ヘキサンジオール、２，２－ビス（トリフルオロメチル）プロパノール及び１Ｈ，１Ｈ－トリフルオロエタノール（ＴＦＥＯ）等が挙げられるが、前述の沸点及び層材料の溶解性の観点からＴＦＰＯ、ＯＦＡＯ及びＨＦＢＯが好ましい。 Examples of fluorinated alcohols include 1H,1H-pentafluoropropanol, 6-(perfluoroethyl)hexanol, 1H,1H-heptafluorobutanol, 2-(perfluorobutyl)ethanol (FBEO), 3-(perfluorobutyl ) propanol, 6-(perfluorobutyl) hexanol, 2-perfluoropropoxy-2,3,3,3-tetrafluoropropanol, 2-(perfluorohexyl) ethanol, 3-(perfluorohexyl) propanol, 6- (perfluorohexyl)hexanol, 1H,1H-(perfluorohexyl)hexanol, 6-(perfluoro-1-methylethyl)hexanol, 1H,1H,3H-tetrafluoropropanol (TFPO), 1H,1H,5H- octafluoropentanol (OFAO), 1H,1H,7H-dodecafluoroheptanol (DFHO), 2H-hexafluoro-2-propanol, 1H,1H,3H-hexafluorobutanol (HFBO), 2,2,3, 3,4,4,5,5-octafluoro-1,6-hexanediol, 2,2-bis(trifluoromethyl)propanol and 1H,1H-trifluoroethanol (TFEO), etc., but the above-mentioned TFPO, OFAO and HFBO are preferred from the viewpoint of boiling point and solubility of the layer material.
　また、フッ化エーテルとしては、例えばヘキサフルオロジメチルエーテル、ペルフルオロジメトキシメタン、ペルフルオロオキセタン、ペルフルオロ－１，３－ジオキソラン、１，１，２，２－テトラフルオロエチル－２，２，３，３－テトラフルオロプロピルエーテル等が挙げられる。 Examples of fluorinated ethers include hexafluorodimethyl ether, perfluorodimethoxymethane, perfluorooxetane, perfluoro-1,3-dioxolane, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoro Propyl ether etc. are mentioned.
　また、フッ化エステルとしては、例えばメチルパーフルオロブチレート、エチルパーフルオロブチレート、メチルパーフルオロプロピオネート、メチルジフルオロアセテート、エチルジフルオロアセテート、メチル－２－トリフルオロメチル－３，３，３－トリフルオロプロピオネート等が挙げられる。 Examples of fluorinated esters include methyl perfluorobutyrate, ethyl perfluorobutyrate, methyl perfluoropropionate, methyl difluoroacetate, ethyl difluoroacetate, methyl-2-trifluoromethyl-3,3,3- and trifluoropropionate.
　絶縁層形成用塗布液中、絶縁性化合物の含有量は０．０５～１０質量％の範囲内、極性フッ化溶媒の含有量は９０～９９．９５質量％の範囲内であることが好ましい。 The content of the insulating compound is preferably within the range of 0.05 to 10% by mass, and the content of the polar fluorinated solvent is preferably within the range of 90 to 99.95% by mass in the coating liquid for forming the insulating layer.
　また、極性フッ化溶媒としては、発光層材料を溶解させないものであれば、二種以上の極性フッ化溶媒の混合溶媒でも良いし、極性フッ化溶媒と極性フッ化溶媒以外の溶媒との混合溶媒でも良い。
　例えばフッ化アルコールとアルコールとの混合溶媒等を用いることができる。
　混合溶媒を用いる場合、極性フッ化溶媒の含有量は５０質量％以上であることが好ましい。 The polar fluorinated solvent may be a mixed solvent of two or more polar fluorinated solvents, or a mixture of a polar fluorinated solvent and a solvent other than a polar fluorinated solvent, as long as it does not dissolve the light-emitting layer material. A solvent may be used.
For example, a mixed solvent of fluorinated alcohol and alcohol can be used.
When using a mixed solvent, the content of the polar fluorinated solvent is preferably 50% by mass or more.
　〔１．３〕その他の共通構成要素
　以下、発光画像表示部及び非発光画像表示部の両方に関与する共通要素について述べる。 [1.3] Other Common Elements Hereinafter, common elements related to both the light emitting image display section and the non-light emitting image display section will be described.
　〔１．３．１〕基板
　有機ＥＬ素子に用いられる基板の材料には特に限定はなく、好ましくは、例えばガラス、石英又は樹脂フィルム等を挙げることができる。
　特に好ましくは、有機ＥＬ素子にフレキシブル性を与え、印刷物等に内蔵することが可能な樹脂フィルムである。 [1.3.1] Substrate The material of the substrate used in the organic EL device is not particularly limited, and preferable examples include glass, quartz, and resin films.
Particularly preferred is a resin film that imparts flexibility to the organic EL element and can be embedded in a printed matter or the like.
　樹脂フィルムとしては、例えばポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステル、ポリエチレン、ポリプロピレン、セロファン、セルロースジアセテート、セルローストリアセテート（ＴＡＣ）、セルロースアセテートブチレート、セルロースアセテートプロピオネート（ＣＡＰ）、セルロースアセテートフタレート、セルロースナイトレート等のセルロースエステル類又はそれらの誘導体、ポリ塩化ビニリデン、ポリビニルアルコール、ポリエチレンビニルアルコール、シンジオタクティックポリスチレン、ポリカーボネート、ノルボルネン樹脂、ポリメチルペンテン、ポリエーテルケトン、ポリイミド、ポリエーテルスルホン（ＰＥＳ）、ポリフェニレンスルフィド、ポリスルホン類、ポリエーテルイミド、ポリエーテルケトンイミド、ポリアミド、フッ素樹脂、ナイロン、ポリメチルメタクリレート、アクリル又はポリアリレート類、アートン（商品名、ＪＳＲ社製）又はアペル（商品名、三井化学社製）といったシクロオレフィン系樹脂等のフィルムが挙げられる。 Examples of resin films include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate (CAP ), cellulose esters such as cellulose acetate phthalate and cellulose nitrate, or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, Polyethersulfone (PES), polyphenylene sulfide, polysulfones, polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylates, Arton (trade name, manufactured by JSR Corporation) or APEL (trade name, manufactured by Mitsui Chemicals, Inc.).
　樹脂フィルムの表面には、無機物若しくは有機物の被膜又はその両者のハイブリッド被膜等によるガスバリアー膜が形成されていても良い。
　ガスバリアー膜は、ＪＩＳ　Ｋ　７１２９－１９９２に準拠した方法で測定された水蒸気透過度（２５±０．５℃、湿度（９０±２）％ＲＨ）が０．０１ｇ／（ｍ２・２４ｈ）以下のガスバリアー性フィルムであることが好ましい。
　さらには、ＪＩＳ　Ｋ　７１２６－１９８７に準拠した方法で測定された酸素透過度が、１×１０－３ｍＬ／（ｍ２・２４ｈ・ａｔｍ）以下、水蒸気透過度が、１×１０－５ｇ／（ｍ２・２４ｈ）以下の高ガスバリアー性フィルムであることが好ましい。 A gas barrier film may be formed on the surface of the resin film by a coating of an inorganic substance, an organic substance, or a hybrid coating of both.
The gas barrier film has a water vapor permeability (25±0.5°C, humidity (90±2)% RH) measured by a method conforming to JIS K 7129-1992 of 0.01 g/(m 2 24 h) or less. is preferably a gas barrier film.
Furthermore, the oxygen permeability measured by a method based on JIS K 7126-1987 is 1 × 10 -3 mL / (m 2 · 24 h · atm) or less, and the water vapor permeability is 1 × 10 -5 g / It is preferably a high gas barrier film of (m 2 ·24 h) or less.
　ガスバリアー膜を形成する材料としては、水分や酸素等の浸入を抑制する機能を有する材料であれば良い。
　例えば酸化ケイ素、二酸化ケイ素及び窒化ケイ素等を用いることができる。
　さらに、ガスバリアー膜の脆弱性を改良するために、これら無機層と有機材料からなる層との積層構造を持たせることがより好ましい。
　無機層と有機層の積層順については特に制限はないが、両者を交互に複数回積層させることが好ましい。 As a material for forming the gas barrier film, any material can be used as long as it has a function of suppressing penetration of moisture, oxygen, and the like.
For example, silicon oxide, silicon dioxide and silicon nitride can be used.
Furthermore, in order to improve the fragility of the gas barrier film, it is more preferable to have a laminate structure of these inorganic layers and layers made of organic materials.
The order of lamination of the inorganic layer and the organic layer is not particularly limited, but it is preferable to alternately laminate the two layers a plurality of times.
　ガスバリアー膜の形成方法については特に限定はなく、例えば真空蒸着法、スパッタリング法、反応性スパッタリング法、分子線エピタキシー法、クラスターイオンビーム法、イオンプレーティング法、プラズマ重合法、大気圧プラズマ重合法、プラズマＣＶＤ法、レーザーＣＶＤ法、熱ＣＶＤ法及びコーティング法等を用いることができる。
　例えば特開２００４－６８１４３号公報に記載されているような大気圧プラズマ重合法によるものが好ましい。 The method for forming the gas barrier film is not particularly limited, and examples include vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, and atmospheric pressure plasma polymerization. , a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used.
For example, atmospheric pressure plasma polymerization as described in JP-A-2004-68143 is preferred.
　〔１．３．２〕封止
　本発明の有機ＥＬ素子の封止に用いられる封止手段としては、例えば封止部材と、電極、支持基板とを接着剤で接着する方法を挙げることができる。 [1.3.2] Sealing As a sealing means used for sealing the organic EL device of the present invention, for example, a method of adhering a sealing member, an electrode, and a supporting substrate with an adhesive can be mentioned. .
　封止部材としては、有機ＥＬ素子の表示領域を覆うように配置されていれば良く、凹板状でも、平板状でも良い。
　また、透明性、電気絶縁性は特に限定されない。 The sealing member may be arranged so as to cover the display area of the organic EL element, and may be in the form of a concave plate or a flat plate.
Moreover, transparency and electric insulation are not particularly limited.
　具体的には、ガラス板、ポリマー板・フィルム及び金属板・フィルム等が挙げられる。
　ガラス板としては、特にソーダ石灰ガラス、バリウム・ストロンチウム含有ガラス、鉛ガラス、アルミノケイ酸ガラス、ホウケイ酸ガラス、バリウムホウケイ酸ガラス及び石英等を挙げることができる。
　また、ポリマー板としては、ポリカーボネート、アクリル、ポリエチレンテレフタレート、ポリエーテルサルファイド及びポリサルフォン等を挙げることができる。
　金属板としては、ステンレス、鉄、銅、アルミニウム、マグネシウム、ニッケル、亜鉛、クロム、チタン、モリブデン、シリコン、ゲルマニウム及びタンタルからなる群から選ばれる一種以上の金属又は合金からなるものが挙げられる。 Specifically, glass plates, polymer plates/films, metal plates/films, and the like can be mentioned.
Examples of glass plates include soda-lime glass, barium-strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass and quartz.
As the polymer plate, polycarbonate, acryl, polyethylene terephthalate, polyether sulfide, polysulfone, and the like can be used.
Metal plates include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium and tantalum.
　本発明においては、有機ＥＬ素子を薄膜化できるということからポリマーフィルム及び金属フィルムを好ましく使用することができる。
　さらには、ポリマーフィルムは、酸素透過度１０－３ｇ／（ｍ２・２４ｈ）以下、水蒸気透過度１０－３ｇ／（ｍ２・２４ｈ）以下のものであることが好ましい。
　また、前記の水蒸気透過度、酸素透過度がいずれも１０－５ｇ／（ｍ２・２４ｈ）以下であることが、更に好ましい。 In the present invention, a polymer film and a metal film can be preferably used because the organic EL element can be made thinner.
Further, the polymer film preferably has an oxygen permeability of 10 −3 g/(m 2 ·24 h) or less and a water vapor permeability of 10 −3 g/(m 2 ·24 h) or less.
Further, it is more preferable that both the water vapor permeability and the oxygen permeability are 10 −5 g/(m 2 ·24 h) or less.
　封止部材を凹状に加工するのは、サンドブラスト加工、化学エッチング加工等が使われる。
　接着剤として具体的には、アクリル酸系オリゴマー、メタクリル酸系オリゴマーの反応性ビニル基を有する光硬化及び熱硬化性接着剤及び２－シアノアクリル酸エステルなどの湿気硬化型等の接着剤を挙げることができる。
　また、エポキシ系等の熱及び化学硬化型（二液混合）を挙げることができる。
　また、ホットメルト型のポリアミド、ポリエステル及びポリオレフィンを挙げることができる。
　また、カチオン硬化タイプの紫外線硬化型エポキシ樹脂接着剤を挙げることができる。 Sandblasting, chemical etching, or the like is used to process the sealing member into a concave shape.
Specific examples of adhesives include photocurable and thermosetting adhesives having reactive vinyl groups of acrylic acid-based oligomers and methacrylic acid-based oligomers, and moisture-curable adhesives such as 2-cyanoacrylic acid esters. be able to.
Thermal and chemical curing types (two-liquid mixture) such as epoxy systems can also be mentioned.
Mention may also be made of hot-melt polyamides, polyesters and polyolefins.
Further, a cationic curing type ultraviolet curing type epoxy resin adhesive can be mentioned.
　前記接着剤中に乾燥剤を分散させておいても良い。
　封止部分への接着剤の塗布は、市販のディスペンサーを使っても良いし、スクリーン印刷のように印刷しても良い。 A desiccant may be dispersed in the adhesive.
A commercially available dispenser may be used to apply the adhesive to the sealing portion, or printing such as screen printing may be used.
　また、有機機能層を挟み支持基板と対向する側の電極の外側に、該電極と有機機能層を被覆し、支持基板と接する形で無機物、有機物の層を形成し封止膜とすることも好適にできる。
　この場合、該膜を形成する材料としては、水分や酸素等素子の劣化をもたらすものの浸入を抑制する機能を有する材料であれば良く、例えば酸化ケイ素、二酸化ケイ素及び窒化ケイ素等を用いることができる。
　さらに、該膜の脆弱性を改良するためにこれら無機層と有機材料からなる層の積層構造を持たせることが好ましい。
　これらの膜の形成方法については、特に限定はなく、例えば真空蒸着法、スパッタリング法、反応性スパッタリング法、分子線エピタキシー法、クラスターイオンビーム法、イオンプレーティング法、プラズマ重合法、大気圧プラズマ重合法、プラズマＣＶＤ法、レーザーＣＶＤ法、熱ＣＶＤ法及びコーティング法などを用いることができる。 Alternatively, the electrode and the organic functional layer may be coated on the outside of the electrode on the side facing the supporting substrate with the organic functional layer interposed therebetween, and inorganic and organic layers may be formed in contact with the supporting substrate to form a sealing film. I can do it well.
In this case, the material for forming the film may be any material that has a function of suppressing the infiltration of substances that cause deterioration of the device, such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, and the like can be used. .
Furthermore, in order to improve the fragility of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of an organic material.
The method for forming these films is not particularly limited. A method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used.
　封止部材と有機ＥＬ素子の表示領域との間隙には、気相及び液相では、窒素、アルゴン等の不活性気体や、フッ化炭化水素、シリコンオイルのような不活性液体を注入することが好ましい。
　また、真空とすることも可能である。
　また、内部に吸湿性化合物を封入することもできる。 An inert gas such as nitrogen or argon, or an inert liquid such as fluorocarbon or silicone oil may be injected into the gap between the sealing member and the display area of the organic EL element in the gas phase and the liquid phase. is preferred.
A vacuum is also possible.
Also, a hygroscopic compound can be sealed inside.
　吸湿性化合物としては、例えば金属酸化物（例えば酸化ナトリウム、酸化カリウム、酸化カルシウム、酸化バリウム、酸化マグネシウム、酸化アルミニウム等）、硫酸塩（例えば硫酸ナトリウム、硫酸カルシウム、硫酸マグネシウム、硫酸コバルト等）、金属ハロゲン化物（例えば塩化カルシウム、塩化マグネシウム、フッ化セシウム、フッ化タンタル、臭化セリウム、臭化マグネシウムヨウ化バリウム、ヨウ化マグネシウム等）及び過塩素酸類（例えば過塩素酸バリウム、過塩素酸マグネシウム等）等が挙げられ、硫酸塩、金属ハロゲン化物及び過塩素酸類においては無水塩が好適に用いられる。 Examples of hygroscopic compounds include metal oxides (e.g. sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (e.g. sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate, etc.), Metal halides (e.g. calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide barium iodide, magnesium iodide, etc.) and perchlorates (e.g. barium perchlorate, magnesium perchlorate etc.), etc., and anhydrous salts are preferably used for sulfates, metal halides and perchlorates.
　（保護膜、保護板）
　有機機能層を挟み支持基板と対向する側の封止膜又は封止用フィルムの外側に、素子の機械的強度を高めるために、保護膜又は保護板を設けても良い。
　特に、封止が封止膜により行われている場合には、その機械的強度は必ずしも高くないため、このような保護膜、保護板を設けることが好ましい。
　これに使用することができる材料としては、上記封止に用いたのと同様なガラス板、ポリマー板・フィルム、金属板・フィルム等を用いることができるが、軽量、かつ、薄膜化ということからポリマーフィルムを用いることが好ましい。 (protective film, protective plate)
A protective film or a protective plate may be provided on the outside of the sealing film or film for sealing on the side facing the support substrate with the organic functional layer interposed therebetween in order to increase the mechanical strength of the element.
In particular, when sealing is performed by a sealing film, the mechanical strength thereof is not necessarily high, so it is preferable to provide such a protective film or protective plate.
As a material that can be used for this, the same glass plate, polymer plate/film, metal plate/film, etc. used for the above sealing can be used. It is preferred to use polymer films.
　〔１．３．３〕光取り出し向上技術
　有機ＥＬ素子は、空気よりも屈折率の高い（屈折率１．６～２．１程度の範囲内）層の内部で発光し、発光層で発生した光のうち１５～２０％程度の範囲内の光しか取り出せないことが一般的に言われている。 [1.3.3] Technology for improving light extraction The organic EL element emits light inside a layer with a higher refractive index than air (within a refractive index range of about 1.6 to 2.1). It is generally said that only light within the range of about 15 to 20% of the light can be extracted.
　これは、臨界角以上の角度θで界面（透明基板と空気との界面）に入射する光は、全反射を起こし素子外部に取り出すことができないことや、透明電極又は発光層と透明基板との間で光が全反射を起こし、光が透明電極又は発光層を導波し、結果として、光が素子側面方向に逃げるためである。 This is because light incident on the interface (interface between the transparent substrate and the air) at an angle θ greater than the critical angle is totally reflected and cannot be taken out of the element, and the light between the transparent electrode or the light-emitting layer and the transparent substrate cannot be extracted. This is because the light is totally reflected between them, the light is guided through the transparent electrode or the light-emitting layer, and as a result, the light escapes in the lateral direction of the device.
　この光の取り出しの効率を向上させる手法としては、例えば透明基板表面に凹凸を形成し、透明基板と空気界面での全反射を防ぐ方法（例えば米国特許第４７７４４３５号明細書）、基板に集光性を持たせることにより効率を向上させる方法（例えば特開昭６３－３１４７９５号公報）、素子の側面等に反射面を形成する方法（例えば特開平１－２２０３９４号公報）、基板と発光体の間に中間の屈折率を持つ平坦層を導入し、反射防止膜を形成する方法（例えば特開昭６２－１７２６９１号公報）、基板と発光体の間に基板よりも低屈折率を持つ平坦層を導入する方法（例えば特開２００１－２０２８２７号公報）、基板、透明電極層や発光層のいずれかの層間（含む、基板と外界間）に回折格子を形成する方法（特開平１１－２８３７５１号公報）などが挙げられる。 Methods for improving the efficiency of extracting light include, for example, forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (see, for example, US Pat. No. 4,774,435); A method of improving efficiency by imparting properties (for example, JP-A-63-314795), a method of forming a reflective surface on the side surface of an element (for example, JP-A-1-220394), a substrate and a light emitter A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between them (for example, JP-A-62-172691), a flat layer having a lower refractive index than the substrate between the substrate and the light emitter (for example, Japanese Patent Application Laid-Open No. 2001-202827), a method of forming a diffraction grating between any of the substrate, the transparent electrode layer and the light emitting layer (including, between the substrate and the outside world) (Japanese Patent Application Laid-Open No. 11-283751 publication) and the like.
　本発明においては、これらの方法を前記有機ＥＬ素子と組み合わせて用いることができるが、基板と発光体の間に基板よりも低屈折率を持つ平坦層を導入する方法、又は基板、透明電極層や発光層のいずれかの層間若しくは層間を含む、基板と外界間に回折格子を形成する方法を好適に用いることができる。 In the present invention, these methods can be used in combination with the organic EL device. A method of forming a diffraction grating between the substrate and the outside world, including between or between any of the substrate and the light-emitting layer, can be preferably used.
　透明電極と透明基板の間に低屈折率の媒質を光の波長よりも長い厚さで形成すると、透明電極から出てきた光は、媒質の屈折率が低いほど、外部への取り出し効率が高くなる。 When a medium with a low refractive index is formed with a thickness longer than the wavelength of light between the transparent electrode and the transparent substrate, the light emitted from the transparent electrode is more efficiently extracted to the outside as the refractive index of the medium is lower. Become.
　本発明は、これらの手段を組み合わせることにより、さらに高輝度又は耐久性に優れた素子を得ることができる。 By combining these means, the present invention can obtain an element with even higher luminance or excellent durability.
　低屈折率層としては、例えばエアロゲル、多孔質シリカ、フッ化マグネシウム及びフッ素系ポリマーなどが挙げられる。
　透明基板の屈折率は一般に１．５～１．７程度の範囲内であるので、低屈折率層は、屈折率がおよそ１．５以下であることが好ましい。
　また、更に１．３５以下であることが好ましい。 Examples of the low refractive index layer include airgel, porous silica, magnesium fluoride, and fluoropolymers.
Since the refractive index of the transparent substrate is generally in the range of about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less.
Moreover, it is preferable that it is 1.35 or less.
　また、低屈折率媒質の厚さは、媒質中の波長の２倍以上となるのが望ましい。
　これは、低屈折率媒質の厚さが、光の波長程度になってエバネッセントで染み出した電磁波が基板内に入り込む膜厚になると、低屈折率層の効果が薄れるからである。 Moreover, it is desirable that the thickness of the low refractive index medium is at least twice the wavelength in the medium.
This is because when the thickness of the low-refractive-index medium is about the wavelength of light and reaches a thickness at which the electromagnetic wave seeped out by evanescence penetrates into the substrate, the effect of the low-refractive-index layer is weakened.
　全反射を起こす界面又は、いずれかの媒質中に回折格子を導入する方法は、光取り出し効率の向上効果が高いという特徴がある。
　この方法は、回折格子が一次の回折や、二次の回折といった、いわゆるブラッグ回折により、光の向きを屈折とは異なる特定の向きに変えることができる性質を利用して、発光層から発生した光のうち、層間での全反射等により外に出ることができない光を、いずれかの層間又は、媒質中（透明基板内や透明電極内）に回折格子を導入することで光を回折させ、光を外に取り出そうとするものである。 The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving the light extraction efficiency.
This method utilizes the property that a diffraction grating can change the direction of light to a specific direction different from refraction by first-order diffraction, second-order diffraction, or so-called Bragg diffraction. Among light, light that cannot go out due to total reflection between layers or the like is diffracted by introducing a diffraction grating in one of the layers or in the medium (inside the transparent substrate or in the transparent electrode), It's about getting the light out.
　導入する回折格子は、二次元的な周期屈折率を持っていることが望ましい。
　これは、発光層で発光する光はあらゆる方向にランダムに発生するので、ある方向にのみ周期的な屈折率分布を持っている一般的な一次元回折格子では、特定の方向に進む光しか回折されず、光の取り出し効率がさほど上がらない。 The diffraction grating to be introduced preferably has a two-dimensional periodic refractive index.
This is because the light emitted from the light-emitting layer is randomly generated in all directions, so a general one-dimensional diffraction grating that has a periodic refractive index distribution in only one direction can only diffract light traveling in a specific direction. Therefore, the light extraction efficiency does not increase so much.
　しかしながら、屈折率分布を二次元的な分布にすることにより、あらゆる方向に進む光が回折され、光の取り出し効率が上がる。 However, by making the refractive index distribution two-dimensional, light traveling in all directions is diffracted, increasing the light extraction efficiency.
　回折格子を導入する位置としては、いずれかの層間、又は媒質中（透明基板内や透明電極内）でも良いが、光が発生する場所である有機発光層の近傍が好ましい。
　このとき、回折格子の周期は、媒質中の光の波長の約１／２～３倍程度の範囲内が好ましい。
　回折格子の配列は、正方形のラチス状、三角形のラチス状、ハニカムラチス状など、二次元的に配列が繰り返されることが好ましい。 The position where the diffraction grating is introduced may be between any of the layers or in the medium (inside the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light-emitting layer where light is generated.
At this time, the period of the diffraction grating is preferably in the range of about 1/2 to 3 times the wavelength of light in the medium.
The arrangement of the diffraction gratings is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.
　〔１．３．４〕集光シート
　本発明の有機ＥＬ素子は、支持基板（基板）の光取出し側に、例えばマイクロレンズアレイ上の構造を設けるように加工すること、又は、いわゆる集光シートと組み合わせることにより、特定方向、例えば素子発光面に対し正面方向に集光することにより、特定方向上の輝度を高めることができる。 [1.3.4] Light Condensing Sheet The organic EL element of the present invention is processed so as to provide a structure on the light extraction side of the support substrate (substrate), for example, a microlens array, or a so-called light condensing sheet. By combining with , the luminance in a specific direction can be increased by condensing light in a specific direction, for example, in the front direction with respect to the light emitting surface of the element.
　マイクロレンズアレイの例としては、支持基板の光取り出し側に一辺が３０μｍでその頂角が９０°となるような四角錐を二次元に配列する。
　一辺は１０～１００μｍの範囲内が好ましい。
　これより小さくなると回折の効果が発生して色付く、大きすぎると厚さが厚くなり好ましくない。 As an example of the microlens array, square pyramids each having a side of 30 μm and an apex angle of 90° are arranged two-dimensionally on the light extraction side of the support substrate.
One side is preferably within the range of 10 to 100 μm.
If it is smaller than this, the effect of diffraction will occur and coloring will occur.
　集光シートとしては、例えば液晶表示装置のＬＥＤバックライトで実用化されているものを用いることが可能である。
　このようなシートとして例えば住友スリーエム社製輝度上昇フィルム（ＢＥＦ）などを用いることができる。
　プリズムシートの形状としては、例えば基板に頂角９０°、ピッチ５０μｍの△状のストライプが形成されたものであってもよいし、頂角が丸みを帯びた形状、ピッチをランダムに変化させた形状、その他の形状であっても良い。 As the condensing sheet, it is possible to use, for example, a material that has been put to practical use in the LED backlight of the liquid crystal display device.
For example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Co., Ltd. can be used as such a sheet.
The shape of the prism sheet may be, for example, a substrate on which delta-shaped stripes with an apex angle of 90° and a pitch of 50 μm are formed. A shape or other shape may be used.
　また、有機ＥＬ素子からの光放射角を制御するために光拡散板・フィルムを、集光シートと併用してもよい。
　例えば（株）きもと製拡散フィルム（ライトアップ）などを用いることができる。 In addition, a light diffusing plate/film may be used together with the condensing sheet in order to control the light emission angle from the organic EL element.
For example, a diffusion film (light up) manufactured by Kimoto Co., Ltd. can be used.
　〔１．４〕有機エレクトロルミネッセンス素子のその他の構成
　本発明に適用可能な有機ＥＬ素子の構成のその他の概要については、例えば特開２０１３－１５７６３４号公報、特開２０１３－１６８５５２号公報、特開２０１３－１７７３６１号公報、特開２０１３－１８７２１１号公報、特開２０１３－１９１６４４号公報、特開２０１３－１９１８０４号公報、特開２０１３－２２５６７８号公報、特開２０１３－２３５９９４号公報、特開２０１３－２４３２３４号公報、特開２０１３－２４３２３６号公報、特開２０１３－２４２３６６号公報、特開２０１３－２４３３７１号公報、特開２０１３－２４５１７９号公報、特開２０１４－００３２４９号公報、特開２０１４－００３２９９号公報、特開２０１４－０１３９１０号公報、特開２０１４－０１７４９３号公報及び特開２０１４－０１７４９４号公報等に記載されている構成を挙げることができる。 [1.4] Other configurations of the organic electroluminescence element For other outlines of the configuration of the organic EL element applicable to the present invention, for example, JP-A-2013-157634, JP-A-2013-168552, and JP-A-2013-168552 2013-177361, JP 2013-187211, JP 2013-191644, JP 2013-191804, JP 2013-225678, JP 2013-235994, JP 2013- 243234, JP 2013-243236, JP 2013-242366, JP 2013-243371, JP 2013-245179, JP 2014-003249, JP 2014-003299 Configurations described in JP-A-2014-013910, JP-A-2014-017493 and JP-A-2014-017494 can be mentioned.
　また、タンデム型の有機ＥＬ素子の具体例としては、例えば米国特許第６３３７４９２号明細書、米国特許第７４２０２０３号明細書、米国特許第７４７３９２３号明細書、米国特許第６８７２４７２号明細書、米国特許第６１０７７３４号明細書、米国特許第６３３７４９２号明細書、特開２００６－２２８７１２号公報、特開２００６－２４７９１号公報、特開２００６－４９３９３号公報、特開２００６－４９３９４号公報、特開２００６－４９３９６号公報、特開２０１１－９６６７９号公報、特開２００５－３４０１８７号公報、特許第４７１１４２４号公報、特許第３４９６６８１号公報、特許第３８８４５６４号公報、特許第４２１３１６９号公報、特開２０１０－１９２７１９号公報、特開２００９－０７６９２９号公報、特開２００８－０７８４１４号公報、特開２００７－０５９８４８号公報、特開２００３－２７２８６０号公報、特開２００３－０４５６７６号公報、国際公開第２００５／００９０８７号及び国際公開第２００５／０９４１３０号等に記載の素子構成や構成材料等が挙げられるが、本発明はこれらに限定されない。 Further, as specific examples of the tandem-type organic EL element, for example, US Pat. No. 6,337,492, US Pat. 6107734, US Patent No. 6337492, JP 2006-228712, JP 2006-24791, JP 2006-49393, JP 2006-49394, JP 2006-49396 JP, JP 2011-96679, JP 2005-340187, JP 4711424, JP 3496681, JP 3884564, JP 4213169, JP 2010-192719 , JP 2009-076929, JP 2008-078414, JP 2007-059848, JP 2003-272860, JP 2003-045676, International Publication No. 2005/009087 and International Although the device configuration, constituent materials, and the like described in Japanese Unexamined Patent Publication No. 2005/094130 and the like can be mentioned, the present invention is not limited thereto.
　〔２〕有機エレクトロルミネッセンス素子の製造方法
　図１に示す有機ＥＬ素子１０を製造する場合を例にとって、本発明の有機ＥＬ素子の製造方法の一例を具体的に説明する。 [2] Method for Manufacturing Organic Electroluminescence Element An example of the method for manufacturing the organic EL element of the present invention will be described in detail, taking as an example the case of manufacturing the organic EL element 10 shown in FIG.
　まず、基板１１上に、陽極１２を形成する。
　次に、陽極１２上に、絶縁層２を形成し、絶縁層２の凹部に、正孔注入層１３及び正孔輸送層１４をこの順に形成する。
　次に、発光層形成用塗布液を用いて発光層１５を形成する。
　次に、発光層１５上に、電子輸送層形成用塗布液を用いて電子輸送層１６を形成する。
　次に、電子輸送層１６上に、電子注入層１７及び陰極１８を形成する。
　陽極１２及び陰極１８は発光層に対して共通の電極を形成している。
　同様にして、青色（Ｂ）発光画素２１、緑色（Ｇ）発光画素２２及び赤色（Ｒ）発光画素２３を形成する。
　ただし、発光画素は、前記Ｂ、Ｇ、Ｒの発光画素に加えて、４色（Ｂ，Ｇ、Ｒ及びＷ（白色））や、５色（Ｂ，Ｇ、Ｒ、Ｗ（白色）、ＬＢ（ＢとＧの混色）及びＯ（ＧとＲの混色）である構成にすることも好ましく、これらの発光色から画像部に合う一種類以上の構成を選択することができる。 First, the anode 12 is formed on the substrate 11 .
Next, the insulating layer 2 is formed on the anode 12, and the hole injection layer 13 and the hole transport layer 14 are formed in this order in the concave portions of the insulating layer 2. Next, as shown in FIG.
Next, the light-emitting layer 15 is formed using the light-emitting layer forming coating solution.
Next, an electron transport layer 16 is formed on the light emitting layer 15 using a coating solution for forming an electron transport layer.
Next, an electron injection layer 17 and a cathode 18 are formed on the electron transport layer 16 .
Anode 12 and cathode 18 form a common electrode for the light emitting layer.
Similarly, a blue (B) light-emitting pixel 21, a green (G) light-emitting pixel 22, and a red (R) light-emitting pixel 23 are formed.
However, in addition to the B, G, and R light-emitting pixels, the light-emitting pixels include four colors (B, G, R, and W (white)), five colors (B, G, R, W (white), and LB). (Mixed color of B and G) and O (Mixed color of G and R) are also preferable, and one or more types of configurations suitable for the image area can be selected from these emission colors.
　なお、有機ＥＬ素子１０を構成する発光層以外の各層の形成方法としては、上記したとおり、湿式法、蒸着及びスパッタ等いずれの方法であってもよい。
　また、発光層及び電子輸送層の形成についても、湿式法に限らず、蒸着やスパッタ等の方法を用いてもよい。
　ただし、有機ＥＬ素子１０を構成するいずれの層も、コストの観点から、湿式法を用いることが好ましい。 As a method for forming each layer other than the light-emitting layer that constitutes the organic EL element 10, any method such as a wet method, vapor deposition, or sputtering may be used as described above.
Also, the formation of the light-emitting layer and the electron transport layer is not limited to the wet method, and a method such as vapor deposition or sputtering may be used.
However, from the viewpoint of cost, it is preferable to use a wet method for any of the layers constituting the organic EL element 10 .
　最後に、陰極１８を形成した後の素子を封止する（不図示）。
　当該素子の封止に用いられる封止手段としては、公知の部材、方法を使用することができる。 Finally, the device after forming the cathode 18 is sealed (not shown).
As the sealing means used for sealing the element, known members and methods can be used.
　なお、有機ＥＬ素子１０を構成するバンク以外の各層の形成方法としては、上記したとおり、湿式法、蒸着及びスパッタ等いずれの方法であってもよい。
　ただし、発光層については、大気下製造時の性能低下が抑制されており、コストが抑えられることから、湿式法を用いることが好ましく、インクジェット印刷法を用いるのが特に好ましい。 Incidentally, as a method for forming each layer other than the bank constituting the organic EL element 10, any method such as a wet method, vapor deposition, and sputtering may be used as described above.
However, for the light-emitting layer, it is preferable to use a wet method, and particularly preferably to use an inkjet printing method, because deterioration in performance during manufacturing in the air is suppressed and costs are suppressed.
　インクジェット印刷法に用いられる液媒体としては、例えばメチルエチルケトン、シクロヘキサノン等のケトン類、酢酸エチル、酢酸イソプロピル、プロピレングリコールモノメチルエーテルアセテート、３－メトキシブチルアセテート等の脂肪酸エステル類、ジクロロベンゼン等のハロゲン化炭化水素類、トルエン、キシレン、メシチレン、シクロヘキシルベンゼン等の芳香族炭化水素類、メタノール、エタノール、プロパノール、イソプロパノール等の非フッ化アルコール類、トリフルオロエタノール（ＴＦＥＯ）、テトラフルオロプロパノール（ＴＦＰＯ）、ヘキサフルオロプロパノール（ＨＦＰＯ）等のフッ化アルコール類、シクロヘキサン、デカリン、ドデカン等の脂肪族炭化水素類、ＤＭＦ及びＤＭＳＯ等の有機溶媒を用いることができるが、素子中の含まれる溶媒量を抑制する点から、沸点が５０～１８０℃の範囲内の溶媒が好適に用いられる。
　また、分散方法としては、超音波、高剪断力分散やメディア分散等の分散方法により分散することができる。 Examples of liquid media used in inkjet printing include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, isopropyl acetate, propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate, and halogenated carbons such as dichlorobenzene. Hydrogens, toluene, xylene, mesitylene, aromatic hydrocarbons such as cyclohexylbenzene, non-fluorinated alcohols such as methanol, ethanol, propanol, isopropanol, trifluoroethanol (TFEO), tetrafluoropropanol (TFPO), hexafluoro Fluorinated alcohols such as propanol (HFPO), aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO can be used. , a solvent having a boiling point within the range of 50 to 180° C. is preferably used.
Moreover, as a dispersion method, it can be dispersed by a dispersion method such as ultrasonic wave, high shear force dispersion, media dispersion, or the like.
　本発明において、有機ＥＬ素子中に含まれる溶媒含有量としては、０．０１～１μｇ／ｃｍ２の範囲内である。
　０．０１μｇ／ｃｍ２以下の場合には、有機膜が疎となるため素子駆動時の高電圧化を引き起こし、１μｇ／ｃｍ２以上の場合には素子駆動時の物質拡散や発光材料の凝集を引き起こし、低効率、低駆動寿命となってしまう。
　これらの溶媒含有量は昇温脱離ガス分光法により求めることができる。 In the present invention, the solvent content contained in the organic EL element is within the range of 0.01 to 1 μg/cm 2 .
When the concentration is 0.01 μg/cm 2 or less, the organic film becomes sparse, which causes a high voltage when the device is driven. resulting in low efficiency and a short drive life.
These solvent contents can be determined by thermal desorption spectroscopy.
　（インクジェット印刷法）
　本発明に係る発光層は、インクジェット印刷法により形成することが好ましく、特に大気下でのインクジェット印刷法により形成することが好ましい。
　インクジェット印刷法等の液滴吐出法により成膜される場合のほうが、蒸着やスピンコートなどで成膜する場合よりも成膜雰囲気の活性ガスの影響が顕著であり、発光効率の低下や短寿命化の影響をより受けやすいが、このような場合でも、性能低下を生じることなく発光する。
　従って、大気下での製造が可能であり、不活性ガスや真空設備の製造コストも下げることができる。
　なお、有機ＥＬ素子を構成するその他の層の形成方法については限定されず、インクジェット印刷法であっても、その他の方法であってもよい。 (Inkjet printing method)
The luminescent layer according to the present invention is preferably formed by an inkjet printing method, particularly preferably by an inkjet printing method in the atmosphere.
In the case of forming a film by a droplet ejection method such as an inkjet printing method, the effect of the active gas in the film forming atmosphere is more pronounced than in the case of forming a film by vapor deposition or spin coating, resulting in a decrease in luminous efficiency and a short life. However, even in such cases, it emits light without degradation in performance.
Therefore, manufacturing in the atmosphere is possible, and manufacturing costs for inert gas and vacuum equipment can be reduced.
The method of forming other layers constituting the organic EL element is not limited, and may be an inkjet printing method or other methods.
　インクジェット印刷法で用いられるインクジェットヘッドとしては、オンデマンド方式でもコンティニュアス方式でもよい。
　また、吐出方式としては、電気－機械変換方式（例えばシングルキャビティー型、ダブルキャビティー型、ベンダー型、ピストン型、シェアーモード型、シェアードウォール型等）、電気－熱変換方式（例えばサーマルインクジェット型、バブルジェット（登録商標）型等）、静電吸引方式（例えば電界制御型、スリットジェット型等）及び放電方式（例えばスパークジェット型等）などを具体的な例として挙げることができるが、いずれの吐出方式を用いてもよい。
　また、印字方式としては、シリアルヘッド方式及びラインヘッド方式等を制限なく用いることができる。 The inkjet head used in the inkjet printing method may be of an on-demand system or a continuous system.
In addition, as the ejection method, an electro-mechanical conversion method (eg, single cavity type, double cavity type, bender type, piston type, share mode type, shared wall type, etc.), an electro-thermal conversion method (eg, thermal ink jet type) , bubble jet (registered trademark) type, etc.), an electrostatic attraction method (e.g., electric field control type, slit jet type, etc.), and a discharge method (e.g., spark jet type, etc.) can be mentioned as specific examples. may be used.
Moreover, as a printing method, a serial head method, a line head method, or the like can be used without limitation.
　ヘッドから射出するインク滴の体積は、０．５～１００ｐＬの範囲内とすることが好ましい。
　塗布ムラが少なく、かつ印字速度を高速化できる観点から、２～５０ｐＬの範囲内であることが、より好ましい。
　なお、インク滴の体積は、印加電圧の調整等によって適宜調整可能である。 The volume of ink droplets ejected from the head is preferably in the range of 0.5 to 100 pL.
It is more preferably in the range of 2 to 50 pL from the viewpoint of reducing coating unevenness and increasing the printing speed.
Note that the volume of the ink droplet can be appropriately adjusted by adjusting the applied voltage or the like.
　印字解像度は、好ましくは１８０～１００００ｄｐｉ（ｄｏｔｓ　ｐｅｒ　ｉｎｃｈ）の範囲内、より好ましくは３６０～２８８０ｄｐｉの範囲内で、湿潤厚さとインク滴の体積等を考慮して適宜設定することができる。 The print resolution is preferably within the range of 180 to 10,000 dpi (dots per inch), more preferably within the range of 360 to 2,880 dpi, and can be appropriately set in consideration of wet thickness, volume of ink droplets, and the like.
　本発明において、インクジェット塗布時（塗布直後）における湿潤塗膜の湿潤厚さは、適宜設定することができるが、好ましくは１～１００μｍの範囲内、より好ましくは１～３０μｍの範囲内、最も好ましくは１～５μｍの範囲内において、本発明の効果がより顕著に奏される。
　なお、湿潤厚さは、塗布面積、印字解像度及びインク滴の体積から算出できる。 In the present invention, the wet thickness of the wet coating film at the time of inkjet coating (immediately after coating) can be appropriately set, preferably within the range of 1 to 100 μm, more preferably within the range of 1 to 30 μm, most preferably within the range of 1 to 30 μm. is within the range of 1 to 5 μm, the effect of the present invention is exhibited more remarkably.
The wet thickness can be calculated from the coating area, print resolution, and ink droplet volume.
　インクジェットによる印字方法には、ワンパス印字法とマルチパス印字法がある。
　ワンパス印字法は、所定の印字領域を１回のヘッドスキャンで印字する方法である。
　対して、マルチパス印字法は、所定の印字領域を複数回のヘッドスキャンで印字する方法である。 Inkjet printing methods include a one-pass printing method and a multi-pass printing method.
The one-pass printing method is a method of printing a predetermined print area by one head scan.
On the other hand, the multi-pass printing method is a method of printing a predetermined print area by multiple head scans.
　ワンパス印字法では、所望とする塗布パターンの幅以上の幅にわたってノズルが並設された広幅のヘッドを用いることが好ましい。
　同一の基板上に、互いにパターンが連続していない独立した複数の塗布パターンを形成する場合は、少なくとも各塗布パターンの幅以上の広幅ヘッドを用いればよい。 In the one-pass printing method, it is preferable to use a wide head in which nozzles are arranged over a width equal to or greater than the width of the desired coating pattern.
When forming a plurality of independent coating patterns that are not continuous on the same substrate, a wide head that is at least as wide as the width of each coating pattern may be used.
　以下、インクジェット印刷法による有機機能層の形成方法について、その一例を、図を交えて説明する。 An example of a method for forming an organic functional layer by inkjet printing will be described below with reference to the drawings.
　図２に有機ＥＬ素子１０の表面に対して垂直方向から見たとき、ドット状に前記発光画素２１～２３が配置されていることを表す概念図を示す。
　それぞれのドットの位置は、規則正しい順列であっても、千鳥配列であってもよい。中でも千鳥配列であることがより好ましい。 FIG. 2 shows a conceptual diagram showing that the luminescent pixels 21 to 23 are arranged in dots when viewed from the direction perpendicular to the surface of the organic EL element 10 .
The position of each dot may be in a regular permutation or in a staggered arrangement. Among them, a staggered arrangement is more preferable.
　図４Ａ、図４Ｂ及び図４Ｃは、本発明の有機ＥＬ素子の製造方法に適用可能なシングルパス方式（ラインヘッド方式）のインクジェット記録装置の一例を示す模式図である。
　図４Ａにおいて、１００がラインヘッド型のヘッドユニットであり、それぞれ色相の異なるインク（例えばレッド（Ｒ）、グリーン（Ｇ）及びブルー（Ｂ）色の発光をする化合物を含有するインク）を吐出するヘッド１０２～１０４で構成され、各ヘッドのノズルピッチは３６０ｄｐｉ程度であることが好ましい。
　なお、本発明でいうｄｐｉとは、２．５４ｃｍ当たりのドット数を表す。
　基板１は、ロール状に積層された状態で、搬送機構１０１より矢印方向に繰り出される。 4A, 4B, and 4C are schematic diagrams showing an example of a single-pass system (line head system) inkjet recording apparatus applicable to the method for manufacturing an organic EL element of the present invention.
In FIG. 4A, 100 is a line head type head unit that ejects inks of different hues (for example, inks containing compounds that emit red (R), green (G), and blue (B) colors). It is preferably composed of heads 102 to 104 and the nozzle pitch of each head is about 360 dpi.
The dpi referred to in the present invention represents the number of dots per 2.54 cm.
The substrates 1 are fed out in the direction of the arrow from the transport mechanism 101 in a state of being stacked in a roll.
　図４Ｂは、各ヘッド底部におけるノズルの配置を示す底面図である。
　図４Ｂに示すように、それぞれヘッド１０２とヘッド１０３、ヘッド１０４のノズルＮは、半ピッチずつずらした千鳥配列となっている。
　このようなヘッド構成とすることにより、より緻密な画像を形成することができる。 FIG. 4B is a bottom view showing the arrangement of nozzles at the bottom of each head.
As shown in FIG. 4B, the nozzles N of the head 102, the head 103, and the head 104 are staggered by half a pitch.
With such a head structure, a more dense image can be formed.
　図４Ｃは、ヘッドユニット構成の一例を示す模式図である。
　幅の広い基板１を用いる場合は、基板の全幅をカバーするように複数個のヘッドＨを千鳥配列に配置したヘッドユニットＨＵを用いることも好ましい。 FIG. 4C is a schematic diagram showing an example of a head unit configuration.
When using a wide substrate 1, it is also preferable to use a head unit HU in which a plurality of heads H are arranged in a zigzag arrangement so as to cover the entire width of the substrate.
　前記インクジェット記録装置を用いて、基板を連続的に搬送しながら、基板上に、有機ＥＬ素子の発光層非を形成する発光性ドーパントやホスト化合物等と溶媒を含有する塗布液（インク）、又は、有機機能層を形成する有機機能材料等と溶媒を含有する塗布液（インク）を、インク液滴として順次、基板上に射出して、発光層や有機機能層を形成する。
　本発明に用いられインクジェット記録装置の他にも、例えば特開２０１２－１４００１７号公報、特開２０１３－０１０２２７号公報、特開２０１４－０５８１７１号公報、特開２０１４－０９７６４４号公報、特開２０１５－１４２９７９号公報、特開２０１５－１４２９８０号公報、特開２０１６－００２６７５号公報、特開２０１６－００２６８２号公報、特開２０１６－１０７４０１号公報、特開２０１７－１０９４７６号公報及び特開２０１７－１７７６２６号公報等に記載されている構成からなるインクジェットヘッドを適宜選択して適用することができる。 Using the inkjet recording apparatus, a coating liquid (ink) containing a luminescent dopant, a host compound, or the like that forms the luminescent layer of the organic EL element and a solvent is applied onto the substrate while the substrate is continuously conveyed, or A coating liquid (ink) containing an organic functional material for forming an organic functional layer and a solvent is sequentially ejected as ink droplets onto a substrate to form a light-emitting layer and an organic functional layer.
In addition to the inkjet recording apparatus used in the present invention, for example, JP-A-2012-140017, JP-A-2013-010227, JP-A-2014-058171, JP-A-2014-097644, JP-A-2015- 142979, JP 2015-142980, JP 2016-002675, JP 2016-002682, JP 2016-107401, JP 2017-109476 and JP 2017-177626 An inkjet head having a configuration described in publications and the like can be appropriately selected and applied.
　〔３〕用途
　上述した実施形態の有機ＥＬ素子は、面又は微小発光体であるため、各種の発光光源として用いることができる。 [3] Use Since the organic EL element of the above-described embodiment is a surface or minute light emitter, it can be used as various light sources.
　〔３．１〕照明装置
　例えば家庭用照明や車内照明等の照明装置、時計や液晶用のバックライト、看板広告用照明、信号機の光源、光記憶媒体の光源、電子写真複写機の光源、光通信処理機の光源、光センサーの光源等が挙げられる。 [3.1] Lighting device For example, lighting devices such as home lighting and in-vehicle lighting, backlights for clocks and liquid crystals, lighting for billboard advertisements, light sources for traffic lights, light sources for optical storage media, light sources for electrophotographic copiers, light sources Light sources for communication processors, light sources for optical sensors, and the like.
　〔３．２〕表示装置、印刷造形物
　また、フレキシブル性を活かした、カラーディスプレイとしても有用である。
　特に、本発明の有機ＥＬ素子は簡易な表示装置であるため、二次元インクジェットや３次元インクジェット法によりオンデマンドに対応した細かい作り分けが可能であり、有機ＥＬ素子を内蔵した印刷造形物や三次元造形物などを提供することができる。 [3.2] Display Device, Printed Molded Object Moreover, it is also useful as a color display that takes advantage of its flexibility.
In particular, since the organic EL element of the present invention is a simple display device, it is possible to finely produce according to on-demand by a two-dimensional inkjet method or a three-dimensional inkjet method. It is possible to provide the original model and the like.
　以下、実施例を挙げて本発明を具体的に説明するが、本発明はこれらに限定されるものではない。なお、実施例において「部」又は「％」の表示を用いるが、特に断りがない限り「質量部」又は「質量％」を表す。 The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the examples, "parts" or "%" are used, but "mass parts" or "mass%" are indicated unless otherwise specified.
　以下後述する有機ＥＬ素子において、不活性ガス下にて作製された素子Ｎｏ．にはＡ、大気下にて作製された素子Ｎｏ．にはＢ、正孔移動度測定用として作製された素子Ｎｏ．にはＨ、電子移動度測定用として作製された素子Ｎｏ．にはＥを付する。 In the organic EL elements described below, element No. 1 produced under an inert gas. A, element No. produced in the atmosphere. B, device No. manufactured for hole mobility measurement. H, element No. manufactured for electron mobility measurement. is marked with an E.
　ポリマー（１）～（３０）については、以下の市販品を用いた。
　Ｍｗは、各市販品の重量平均分子量、Ｍｎは数平均分子量、Ｍｖは粘度平均分子量である。
　（１）ポリメチルメタクリレート［Ｍｗ：～１２０ｋ、シグマアルドリッチ社製］
　（２）ポリエチレン［Ｍｗ：～４ｋ、シグマアルドリッチ社製］
　（３）ポリクロロトリフルオロエチレン［ダイキン工業社製、ポリフロン（登録商標）Ｍ－１２］
　（４）ポリフッ化ビニリデン［Ｍｗ：４１０～５７５、Ｐｉｅｚｏｔｅｃｈ社製、Ｐｉｅｚｏｔｅｃｈ（登録商標）ＲＴ－ＴＳ］
　（５）ポリ（３，４－エチレンジオキシチオフェン）［シグマアルドリッチ社製、Ａｅｄｔｒｏｎ　Ｃ－ＮＭ］
　（６）ポリ（２－ビニルピリジン）［Ｍｎ：１５２ｋ、Ｍｗ：１５９ｋ、シグマアルドリッチ社製］
　（７）ポリスチレン－メタクリル酸メチル共重合体［Ｍｗ：１００ｋ～１５０ｋ、ｘ＝４０、ｙ＝６０、シグマアルドリッチ社製］
　（８）ポリ（２，６－ジメチル－１，４－フェニレンオキシド）［Ｍｎ：２０ｋ、Ｍｗ
：３０ｋ、シグマアルドリッチ社製］
　（９）ポリ４，４′－イソプロピリデンジフェニレンテレフタレート［ユニチカ社製　Ｕ－１００］
　（１０）ポリエーテルエーテルケトン［Ｍｎ：～１０．３ｋ、Ｍｗ：～２０．８、シグマアルドリッチ社製］
　（１１）ポリスルホン［Ｍｎ：～２２ｋ、シグマアルドリッチ社製］
　（１２）ポリエーテルスルホン［シグマアルドリッチ社製］
　（１３）ポリカーボネート［シグマアルドリッチ社製、ＧＦ６５５５３５９８］
　（１４）ポリスチレン［Ｍｗ：～２８０ｋ、シグマアルドリッチ社製］
　（１５）ポリ（４－ビニルフェノール）［Ｍｗ：～２５ｋ、シグマアルドリッチ社製］
　（１６）エチレン－テトラフルオロエチレンコポリマー［旭硝子社製、Ｆｌｕｏｎ（登録商標）ＥＴＦＥ］
　（１７）ポリアセタール［ポリプラスチック社製、ジュラコン（登録商標）Ｍ９０］
　（１８）ポリ（１，４－ブチレンテレフタラート）［シグマアルドリッチ社製］
　（１９）ポリエチレンテレフタラート［シグマアルドリッチ社製］
　（２０）ポリイミド［ＤｕＰｏｎｔ社製、Ｖｅｓｐｅｌ（登録商標）ＳＰ－１］
　（２１）ポリアミドイミド［ソルベイ社製、Ｔｏｒｌｏｎ（登録商標）４０００ＴＦ］
　（２２）ポリエーテルイミド［シグマアルドリッチ社製、ｍｅｌｔ　ｉｎｄｅｘ：１８ｇ／１０ｍｉｎ（３３７℃／６．６ｋｇ）］
　（２３）ポリ（３－ヘキシルチオフェン）［Ｍｎ：２７ｋ～４５ｋ、東京化成工業社製］
　（２４）ポリ［２－メトキシ－５－（２′－エチルヘキシルオキシ）－１，４－フェニレンビニレン］［Ｍｎ：４０ｋ～７０ｋ、シグマアルドリッチ社製］
　（２５）アクリロニトリル－スチレン共重合ポリマー［Ｍｗ：～１６５ｋ、ｘ＝７５、ｙ＝２５、シグマアルドリッチ社製］
　（２６）ポリ（９－ビニルカルバゾール）［Ｍｗ：～１１０ｋ、シグマアルドリッチ社製］
　（２７）ポリ（９，９－ジオクチルフルオレン）［Ｍｗ：～２０ｋ、シグマアルドリッチ社製］
　（２８）ポリ（１，４－フェニレンスルフィド）［Ｍｎ：～１０ｋ、シグマアルドリッチ社製］
　（２９）ポリ（９，９－ジオクチルフルオレン－ａｌｔ－ベンゾチアジアゾール）［Ｍｎ：～２５ｋ、シグマアルドリッチ社製］
　（３０）ポリメチルスチレン［Ｍｗ：～７２ｋ、シグマアルドリッチ社製］ The following commercial products were used for the polymers (1) to (30).
Mw is the weight average molecular weight of each commercial product, Mn is the number average molecular weight, and Mv is the viscosity average molecular weight.
(1) Polymethyl methacrylate [Mw: ~120k, manufactured by Sigma-Aldrich]
(2) Polyethylene [Mw: ~4k, manufactured by Sigma-Aldrich]
(3) Polychlorotrifluoroethylene [manufactured by Daikin Industries, Ltd., Polyflon (registered trademark) M-12]
(4) Polyvinylidene fluoride [Mw: 410 to 575, manufactured by Piezotech, Piezotech (registered trademark) RT-TS]
(5) Poly(3,4-ethylenedioxythiophene) [manufactured by Sigma-Aldrich, Aedtron C-NM]
(6) Poly(2-vinylpyridine) [Mn: 152k, Mw: 159k, manufactured by Sigma-Aldrich]
(7) Polystyrene-methyl methacrylate copolymer [Mw: 100k to 150k, x = 40, y = 60, manufactured by Sigma-Aldrich]
(8) Poly(2,6-dimethyl-1,4-phenylene oxide) [Mn: 20k, Mw
: 30k, manufactured by Sigma-Aldrich]
(9) Poly 4,4'-isopropylidenediphenylene terephthalate [Unitika U-100]
(10) Polyetheretherketone [Mn: ~10.3k, Mw: ~20.8, manufactured by Sigma-Aldrich]
(11) Polysulfone [Mn: ~22k, manufactured by Sigma-Aldrich]
(12) Polyethersulfone [manufactured by Sigma-Aldrich]
(13) Polycarbonate [manufactured by Sigma-Aldrich, GF65553598]
(14) Polystyrene [Mw: ~280k, manufactured by Sigma-Aldrich]
(15) Poly(4-vinylphenol) [Mw: ~25k, manufactured by Sigma-Aldrich]
(16) Ethylene-tetrafluoroethylene copolymer [Fluon (registered trademark) ETFE manufactured by Asahi Glass Co., Ltd.]
(17) Polyacetal [Duracon (registered trademark) M90 manufactured by Polyplastics]
(18) Poly(1,4-butylene terephthalate) [manufactured by Sigma-Aldrich]
(19) Polyethylene terephthalate [manufactured by Sigma-Aldrich]
(20) Polyimide [manufactured by DuPont, Vespel (registered trademark) SP-1]
(21) Polyamideimide [manufactured by Solvay, Torlon (registered trademark) 4000TF]
(22) Polyetherimide [manufactured by Sigma-Aldrich, melt index: 18 g/10 min (337°C/6.6 kg)]
(23) Poly(3-hexylthiophene) [Mn: 27k to 45k, manufactured by Tokyo Chemical Industry Co., Ltd.]
(24) Poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] [Mn: 40k to 70k, manufactured by Sigma-Aldrich]
(25) Acrylonitrile-styrene copolymer [Mw: ~165k, x = 75, y = 25, manufactured by Sigma-Aldrich]
(26) Poly(9-vinylcarbazole) [Mw: ~110k, manufactured by Sigma-Aldrich]
(27) Poly(9,9-dioctylfluorene) [Mw: ~20k, manufactured by Sigma-Aldrich]
(28) Poly(1,4-phenylene sulfide) [Mn: ~10k, manufactured by Sigma-Aldrich]
(29) Poly(9,9-dioctylfluorene-alt-benzothiadiazole) [Mn: ~25k, manufactured by Sigma-Aldrich]
(30) Polymethylstyrene [Mw: ~72k, manufactured by Sigma-Aldrich]
　［実施例１］
　＜不活性ガス下における有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ａ（１００Ａ）の製造》
　以下のように、基板上に、陽極／発光層／陰極を積層して封止し、ボトムエミッション型の有機ＥＬ素子１００Ａを製造した。 [Example 1]
<Production of organic EL element under inert gas>
<<Production of Organic EL Element A (100 A)>>
A bottom emission type organic EL element 100A was manufactured by laminating and sealing an anode/light-emitting layer/cathode on a substrate as follows.
　（基板の準備）
　まず、ポリエチレンナフタレートフィルム（帝人デュポン社製、以下、ＰＥＮと略記する。）の陽極を形成する側の全面に、特開２００４－６８１４３号公報に記載の構成の大気圧プラズマ放電処理装置を用いて、酸化ケイ素（ＳｉＯｘ；１＜ｘ≦４）からなる無機物のガスバリアー層を層厚５００ｎｍとなるように形成した。
　これにより、酸素透過度０．００１ｍＬ／（ｍ２・２４ｈ）以下、水蒸気透過度０．００１ｇ／（ｍ２・２４ｈ）以下のガスバリアー性を有する可撓性の基板を作製した。 (Preparation of substrate)
First, an atmospheric pressure plasma discharge treatment apparatus having the configuration described in Japanese Patent Application Laid-Open No. 2004-68143 was used on the entire surface of a polyethylene naphthalate film (manufactured by Teijin DuPont, hereinafter abbreviated as PEN) on the anode forming side. Then, an inorganic gas barrier layer made of silicon oxide (SiOx; 1<x≦4) was formed to a layer thickness of 500 nm.
As a result, a flexible substrate having gas barrier properties with an oxygen permeability of 0.001 mL/(m 2 ·24 h) or less and a water vapor permeability of 0.001 g/(m 2 ·24 h) or less was produced.
　（陽極の形成）
　上記基板上に面積３０ｍｍ、厚さ１２０ｎｍのＩＴＯ（インジウム・スズ酸化物）をスパッタ法により製膜し、フォトリソグラフィー法によりパターニングを行い、陽極を形成した。 (Formation of anode)
An ITO (indium tin oxide) film having an area of 30 mm and a thickness of 120 nm was formed on the substrate by sputtering, and patterned by photolithography to form an anode.
　（絶縁性層（バンク）の形成）
　上記作製した陽極上に、コニカミノルタ製インクジェットヘッド（ＭＥＭＳヘッド１ｐＬ）を用いて、一辺１００μｍの正方形の塗布パターンを１０μｍの間隔を空けて４箇所形成するよう、塗布液を塗布した。
　塗布液としては、トリエチレングリコールモノブチルエーテルを使用した。 (Formation of insulating layer (bank))
The coating solution was applied to the anode prepared above using a Konica Minolta inkjet head (MEMS head 1 pL) so as to form a square coating pattern of 100 μm on a side at four locations with an interval of 10 μm.
Triethylene glycol monobutyl ether was used as the coating liquid.
　次いで大気圧プラズマ放電処理装置を用いて、塗布液を塗布した基板を親液化処理した。
　放電ガスとしてアルゴンガス、反応性ガスとして酸素ガスを用い、２５℃、１Ｌ／（ｍｉｎ・ｃｍ）で供給した。
　また、プラズマ生成に用いた電源は、ハイデン研究所製ＰＨＦ２－Ｋであり、約２ｋＶの電圧をかけてプラズマを生成した。 Then, using an atmospheric pressure plasma discharge treatment apparatus, the substrate coated with the coating liquid was subjected to a lyophilic treatment.
Argon gas was used as the discharge gas, and oxygen gas was used as the reactive gas.
The power source used for plasma generation was PHF2-K manufactured by Heiden Laboratory, and a voltage of about 2 kV was applied to generate plasma.
　次にエアーウォーター製ドライアイス洗浄機を用いて、親液化処理した基板表面を洗浄処理することで、塗布液を除去した。
　これにより、親液領域と撥液領域のパターンが形成された基板を得た。 Next, the coating liquid was removed by cleaning the lyophilic substrate surface using a dry ice cleaner manufactured by Air Water.
As a result, a substrate on which a pattern of lyophilic regions and lyophobic regions was formed was obtained.
　次にコニカミノルタ製インクジェットヘッド（ＭＥＭＳヘッド１ｐＬ）を用いて、親液領域と撥液領域のパターンが形成された前述工程後の基板に信越化学工業製Ｘ－４１－１０５３を３０％にメチルイソブチルケトン５０％とプロピレングリコール２０％を加え、インクを調液し、前記親液領域に塗設した。
　１２０℃で３０ｍｉｎ乾燥後、紫外線を５ｍｉｎ照射し硬化させてバンクを形成した。
　これらバンク壁は、幅１０μｍで格子状に形成されていた。 Next, using an inkjet head (MEMS head 1 pL) manufactured by Konica Minolta, X-41-1053 manufactured by Shin-Etsu Chemical Co., Ltd. was added to 30% methyl isobutyl on the substrate after the above-mentioned process on which the pattern of the lyophilic region and the liquid-repellent region was formed. 50% ketone and 20% propylene glycol were added to prepare an ink, which was applied to the lyophilic region.
After drying at 120° C. for 30 minutes, it was irradiated with ultraviolet rays for 5 minutes and cured to form a bank.
These bank walls were formed in a grid shape with a width of 10 μm.
　（発光層の形成）
　陽極及びバンクを形成した基板をイソプロピルアルコールで超音波洗浄し、乾燥窒素ガスで乾燥し、ＵＶオゾン洗浄を５分間行った。
　次に、窒素雰囲気下で、下記組成の発光層形成用のインク組成物を用い、前述の図４Ａに記載の構造からなるピエゾ方式インクジェットプリンターヘッドであるコニカミノルタ社製のピエゾ方式インクジェットプリンターヘッド「ＫＭ１０２４ｉ」を用いて、４０℃で、乾燥後の層厚が５０ｎｍとなる条件で基板上に射出したのち、１２０℃で３０分間乾燥して、発光層を形成した。 (Formation of light-emitting layer)
The substrate on which the anode and bank were formed was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.
Next, in a nitrogen atmosphere, using an ink composition for forming a light-emitting layer having the following composition, a piezoelectric inkjet printer head manufactured by Konica Minolta, which is a piezoelectric inkjet printer head having the structure shown in FIG. KM1024i" was injected onto a substrate at 40° C. under the condition that the layer thickness after drying was 50 nm, and then dried at 120° C. for 30 minutes to form a light-emitting layer.
　〈発光層形成用塗布液〉
　ホスト化合物ＫＨ－２２　　　　　　　　　　　　１１．４質量部
　発光性ドーパントＲＤ－３　　　　　　　　　　　　３．６質量部
　プロピレングリコールモノメチルエーテルアセテート
　　　　　　　　　　　　　　　　　　　　　　　　２０００質量部 <Coating solution for forming light-emitting layer>
Host compound KH-22 11.4 parts by mass Luminescent dopant RD-3 3.6 parts by mass Propylene glycol monomethyl ether acetate 2000 parts by mass
　（電子注入層及び陰極の形成）
　続いて、基板を真空蒸着装置へ取り付けた。
　また、モリブデン製抵抗加熱ボートにフッ化ナトリウム及びフッ化カリウムを入れたものを真空蒸着装置に取り付け、真空槽を４×１０－５Ｐａまで減圧した。
　その後、ボートに通電して加熱し、フッ化ナトリウムを０．０２ｎｍ／秒で前記発光層及びバンク上に蒸着し、膜厚１ｎｍの薄膜を形成した。
　同様に、フッ化カリウムを０．０２ｎｍ／秒でフッ化ナトリウム薄膜上に蒸着し、層厚１．５ｎｍの電子注入層を形成した。 (Formation of electron injection layer and cathode)
Subsequently, the substrate was attached to the vacuum deposition apparatus.
In addition, a molybdenum resistance heating boat containing sodium fluoride and potassium fluoride was attached to a vacuum deposition apparatus, and the vacuum chamber was evacuated to 4×10 −5 Pa.
After that, the boat was energized and heated, and sodium fluoride was vapor-deposited on the light-emitting layer and bank at 0.02 nm/sec to form a thin film with a thickness of 1 nm.
Similarly, potassium fluoride was vapor-deposited on the sodium fluoride thin film at 0.02 nm/sec to form an electron injection layer with a layer thickness of 1.5 nm.
　引き続き、アルミニウムを蒸着して厚さ１００ｎｍの陰極を形成した。 Subsequently, aluminum was vapor-deposited to form a cathode with a thickness of 100 nm.
　（封止）
　以上の工程により形成した積層体に対し、市販のロールラミネート装置を用いて封止基板を接着した。 (sealing)
A sealing substrate was adhered to the laminate formed by the above steps using a commercially available roll laminator.
　封止基板として、可撓性を有する厚さ３０μｍのアルミニウム箔（東洋アルミニウム（株）製）に、ドライラミネーション用の２液反応型のウレタン系接着剤を用いて層厚１．５μｍの接着剤層を設け、厚さ１２μｍのポリエチレンテレフタレート（ＰＥＴ）フィルムをラミネートしたものを作製した。 As a sealing substrate, a 1.5 μm-thick adhesive was applied to a flexible 30 μm-thick aluminum foil (manufactured by Toyo Aluminum Co., Ltd.) using a two-liquid reactive urethane-based adhesive for dry lamination. A layer was provided and a polyethylene terephthalate (PET) film having a thickness of 12 μm was laminated.
　封止用接着剤として熱硬化性接着剤を、ディスペンサーを使用して封止基板のアルミニウム箔の接着面（つや面）に沿って厚さ２０μｍで均一に塗布した。
　これを１００Ｐａ以下の真空下で１２時間乾燥させた。
　さらに、その封止基板を露点温度－８０℃以下、酸素濃度０．８ｐｐｍの窒素雰囲気下へ移動して、１２時間以上乾燥させ、封止用接着剤の含水率が１００ｐｐｍ以下となるように調整した。 A thermosetting adhesive as a sealing adhesive was uniformly applied to a thickness of 20 μm along the bonding surface (glossy surface) of the aluminum foil of the sealing substrate using a dispenser.
This was dried under a vacuum of 100 Pa or less for 12 hours.
Furthermore, the sealing substrate is moved to a nitrogen atmosphere with a dew point temperature of −80° C. or less and an oxygen concentration of 0.8 ppm, and dried for 12 hours or more, and the moisture content of the sealing adhesive is adjusted to 100 ppm or less. did.
　熱硬化性接着剤としては下記の（Ａ）～（Ｃ）を混合したエポキシ系接着剤を用いた。 As the thermosetting adhesive, an epoxy-based adhesive mixed with the following (A) to (C) was used.
　（Ａ）ビスフェノールＡジグリシジルエーテル（ＤＧＥＢＡ）
　（Ｂ）ジシアンジアミド（ＤＩＣＹ）
　（Ｃ）エポキシアダクト系硬化促進剤 (A) bisphenol A diglycidyl ether (DGEBA)
(B) Dicyandiamide (DICY)
(C) Epoxy adduct curing accelerator
　上記封止基板を上記積層体に対して密着・配置して、圧着ロールを用いて、圧着ロール温度１００℃、圧力０．５ＭＰａ、装置速度０．３ｍ／ｍｉｎの圧着条件で密着封止した。 The above-mentioned sealing substrate was placed in close contact with the above-mentioned laminate, and was tightly sealed using a pressure roll under pressure conditions of a pressure roll temperature of 100°C, a pressure of 0.5 MPa, and an apparatus speed of 0.3 m/min.
　以上のようにして、上述の図１に示す構成の有機ＥＬ素子と同様の形態の有機ＥＬ素子１００Ａを製造した。 As described above, an organic EL element 100A having the same configuration as the organic EL element having the configuration shown in FIG. 1 was manufactured.
　《有機ＥＬ素子Ｈ（１００Ｈ、正孔移動度測定用）の製造》
　上記有機ＥＬ素子１００Ａの製造において、発光層の形成後にＮＰＢ（Ｎ，Ｎ′－ビス（ナフタレン－１－イル）Ｎ，Ｎ′－ビス（フェニル）－ベンジジン）を３０ｎｍ蒸着した後にアルミニウム陰極を蒸着した以外は、同様にして正孔移動度測定用素子（「ホール・オンリー素子」ともいう。）１００Ｈを製造した。
　なお、ＮＰＢが正孔輸送材のため陰極からの電子の注入は起きないため、正孔移動度測定用として使用できる。 <<Manufacture of organic EL element H (100H, for hole mobility measurement)>>
In the production of the organic EL device 100A, after forming the light-emitting layer, NPB (N,N'-bis(naphthalen-1-yl)N,N'-bis(phenyl)-benzidine) was vapor-deposited to a thickness of 30 nm, and then an aluminum cathode was vapor-deposited. A device for hole mobility measurement (also referred to as a “hole-only device”) 100H was manufactured in the same manner, except for the above.
Since NPB is a hole-transporting material, injection of electrons from the cathode does not occur, so it can be used for measuring hole mobility.
　《有機ＥＬ素子Ｅ（１００Ｅ、電子移動度測定用）の製造》
　上記有機ＥＬ素子１００Ａの製造において、発光層の形成前にカルシウムを５ｎｍ蒸着した以外は、同様にして電子移動度測定用素子（「エレクトロン・オンリー素子」ともいう。）１００Ｅを作製した。
　なお、カルシウムが電子注入性材料であり、発光層ＨＯＭＯまでのギャップが大きいことにより、正孔注入が起きないため電子移動度測定用として使用できる。 <<Manufacture of organic EL element E (100E, for electron mobility measurement)>>
An electron mobility measuring device (also referred to as an "electron-only device") 100E was fabricated in the same manner as in the production of the organic EL device 100A, except that calcium was vapor-deposited to a thickness of 5 nm before forming the light-emitting layer.
Calcium is an electron-injecting material and can be used for electron mobility measurement because it does not cause hole injection due to the large gap to the light-emitting layer HOMO.
　《その他の有機ＥＬ素子Ａ、Ｈ及びＥの製造》
　上記不活性ガス下における有機ＥＬ素子１００Ａ、１００Ｈ及び１００Ｅの製造において、発光層の形成における発光層形成用塗布液のポリマーの種類を表I及び表IIのように変更した以外は、同様な方法で各有機ＥＬ素子Ａ（１０１Ａ～１３０Ａ）、Ｈ（１０１Ｈ～１３０Ｈ）及びＥ（１０１Ｅ～１３０Ｅ）を製造した。 <<Production of other organic EL elements A, H and E>>
In the manufacture of the organic EL devices 100A, 100H and 100E under inert gas, the same method was used except that the type of polymer in the coating solution for forming the light-emitting layer was changed as shown in Tables I and II. to manufacture organic EL elements A (101A-130A), H (101H-130H) and E (101E-130E).
　＜大気下での有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ｂ（１００Ｂ）の製造》
　上記不活性ガス下における有機ＥＬ素子１００Ａの製造において、発光層の成膜雰囲気を空気（温度２０℃；湿度５０％）とした以外は、同様にして大気下製造有機ＥＬ素子１００Ｂを製造した。 <Production of organic EL element in air>
<<Production of Organic EL Element B (100B)>>
Organic EL element 100B was produced in the same manner as in the production of organic EL element 100A under the inert gas, except that air (temperature 20° C.; humidity 50%) was used as the atmosphere for film formation of the light-emitting layer.
　《その他の有機ＥＬ素子Ｂの製造》
　上記大気下製造下における有機ＥＬ素子１００Ｂの製造において、発光層の形成における発光層形成用塗布液のポリマーの種類を表I及び表IIのように変更した以外は、同様な方法で各有機ＥＬ素子Ｂ（１０１Ｂ～１３０Ｂ）を製造した。 <<Manufacturing of other organic EL elements B>>
In the manufacture of the organic EL element 100B under the atmosphere, each organic EL device was manufactured in the same manner except that the type of polymer in the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as shown in Tables I and II. Device B (101B-130B) was manufactured.
　≪評価方法≫
　上記方法により製造した有機ＥＬ素子Ａ及びＢについて下記の評価を実施した。
　また、不活性ガス下において作製した有機ＥＬ素子Ｈ及びＥは正孔移動度と電子移動度の常用対数値の差の絶対値を算出することに用いた。 ≪Evaluation method≫
The organic EL devices A and B produced by the above method were evaluated as follows.
Organic EL devices H and E fabricated under an inert gas were used to calculate the absolute value of the difference between the common logarithms of hole mobility and electron mobility.
　（１）移動度差の評価
　不活性ガス下における有機ＥＬ素子Ｈ及びＥのＪ－Ｖ特性（Ｊ：電流密度、Ｖ：印加電圧）を測定した。
　また、下記空間電荷制限電流（ＳＣＬＣ）の理論式より、正孔移動度と電子移動度の常用対数値の差の絶対値を算出した。
　（式）Ｊ＝（９／８）εε０μ（Ｖ２／Ｌ３）
　（上記式中、Ｊは空間電荷制限電流、εは有機薄膜の誘電率、ε０は真空の誘電率、Ｊは電流密度、Ｖは印加電圧である。）
　具体的には、上記式をＪ＝ａＶ２（ａ＝（９／８）εε０μ／Ｌ３）とし、測定値であるＪ及びＶをプロットすることで縦軸をＪ、横軸をＶとしたＪ－Ｖ２のグラフを作成し、その直線の傾きａから各有機ＥＬ素子の電子移動度μｅ及び正孔移動度μｈを算出し、各有機ＥＬ素子の常用対数値の差（ｌｏｇ［電子移動度μｅ］－ｌｏｇ［正孔移動度μｈ］）を求めた。 (1) Evaluation of Mobility Difference JV characteristics (J: current density, V: applied voltage) of organic EL devices H and E were measured under an inert gas.
Also, the absolute value of the difference between the common logarithms of hole mobility and electron mobility was calculated from the following theoretical formula of space charge limited current (SCLC).
(Formula) J = (9/8) εε 0 µ (V 2 /L 3 )
(In the above formula, J is the space charge limited current, ε is the dielectric constant of the organic thin film, ε0 is the vacuum dielectric constant, J is the current density, and V is the applied voltage.)
Specifically, the above formula is J=aV 2 (a=(9/8)εε 0 μ/L 3 ), and the measured values J and V are plotted to plot J on the vertical axis and V on the horizontal axis. Then, the electron mobility μ e and the hole mobility μ h of each organic EL element are calculated from the slope a of the straight line, and the difference between the common logarithms of each organic EL element ( log[electron mobility μ e ]−log[hole mobility μ h ]) was obtained.
　（２）ポリマーの導電率の測定
　上記発光層形成用塗布液から、ホスト化合物及び発光性ドーパントを除いたポリマー単体の塗布液をそれぞれ作製し、別途石英基板上に同様にして成膜した。
　成膜面に対し、日東精工アナリテック社製ハイレスターＵＸを用いて抵抗率を測定し、抵抗率の逆数を導電率として導出した。 (2) Measurement of Conductivity of Polymer A coating solution of polymer alone was prepared by removing the host compound and the luminescent dopant from the coating solution for forming the light-emitting layer, and a film was formed on a quartz substrate in the same manner.
The resistivity of the film-forming surface was measured using Hiresta UX manufactured by Nitto Seiko Analytic Tech, and the reciprocal of the resistivity was derived as the electrical conductivity.
　（３）外部量子収率の評価
　室温（２５［℃］）にて、２．５［ｍＡ／ｃｍ２］の定電流密度条件下による点灯を行い、分光放射輝度計ＣＳ－２０００（コニカミノルタ社製）を用いて、各素子の発光外部量子収率を測定した。
　また、不活性ガス下にて製造した有機ＥＬ素子１００Ａの発光外部量子収率（ＥＱＥ比）を１００とし、不活性ガス下において製造されたその他の有機ＥＬ素子Ａの相対値を求めた。
　さらに、窒素雰囲気下で製造した各有機ＥＬ素子Ａに対して、それぞれ大気下で製造した各有機ＥＬ素子Ｂの発光外部量子収率（ＥＱＥ比）の相対値を求めた。 (3) Evaluation of external quantum yield At room temperature (25 [°C]), lighting was performed under constant current density conditions of 2.5 [mA/cm 2 ], and spectral radiance meter CS-2000 (Konica Minolta Co., Ltd.) ) was used to measure the emission external quantum yield of each device.
Further, the emission external quantum yield (EQE ratio) of the organic EL device 100A manufactured under an inert gas was assumed to be 100, and relative values of the other organic EL devices A manufactured under an inert gas were obtained.
Furthermore, the relative value of the luminescence external quantum yield (EQE ratio) of each organic EL element B manufactured in the atmosphere was obtained with respect to each organic EL element A manufactured in the nitrogen atmosphere.
　（４）駆動寿命の評価
　有機ＥＬ素子の発光特性の評価には、室温（２５［℃］）で、輝度１００［ｃｄ／ｍ２］条件下による点灯を行い、分光放射輝度計ＣＳ－２０００（コニカミノルタ社製）を用いて、各素子の輝度を測定し、不活性ガス下にて製造した有機ＥＬ素子１００Ａの点灯開始から輝度半減までの寿命（ＬＴ比）を１００とし、不活性ガス下において製造されたその他の有機ＥＬ素子Ａの相対値を求めた。
　さらに、窒素雰囲気下で製造した各有機ＥＬ素子Ａに対して、それぞれ大気下で製造した各有機ＥＬ素子Ｂの点灯開始から輝度半減までの寿命（ＬＴ比）の相対値を求めた。
　評価結果を表I及び表IIにまとめて示す。 (4) Evaluation of driving life For evaluation of the light emission characteristics of the organic EL element, lighting was performed at room temperature (25 [° C.]) with a luminance of 100 [cd/m 2 ], and a spectral radiance meter CS-2000 ( Konica Minolta Co., Ltd.), the luminance of each element is measured, and the life (LT ratio) from the start of lighting of the organic EL element 100A manufactured under an inert gas to half the luminance is set to 100, and under the inert gas Relative values of other organic EL elements A manufactured in .
Furthermore, the relative value of the lifetime (LT ratio) from the start of lighting until the brightness is reduced to half of each organic EL element B manufactured in the atmosphere was obtained with respect to each organic EL element A manufactured in the nitrogen atmosphere.
The evaluation results are summarized in Tables I and II.
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000018
　表I及び表IIから、実施例の本発明の有機ＥＬ素子は、比較例の有機ＥＬ素子よりも、発光効率及び駆動寿命が優れており、かつ大気下製造時の性能低下抑制とを両立できることが分かる。 From Tables I and II, it can be seen that the organic EL devices of the present invention of Examples are superior to the organic EL devices of Comparative Examples in terms of luminous efficiency and driving life, and are capable of suppressing deterioration in performance during production in air. I understand.
　表I及び表IIから、赤色リン光発光性ドーパントを使用したときにおいて、導電率が１［Ｓ／ｍ］以下のポリマーを含有している発光層を有する有機ＥＬ素子は、そうでない有機ＥＬ素子に比べて、不活性ガス下におけるＥＱＥ比、ＬＴ比の相対値が高く、それらの値の低下が抑えられていることがわかる。 From Tables I and II, when a red phosphorescent dopant is used, an organic EL device having a light-emitting layer containing a polymer with a conductivity of 1 [S/m] or less is an organic EL device that does not. Compared to , the relative values of the EQE ratio and LT ratio under inert gas are high, and the decrease in these values is suppressed.
　［実施例２］
　＜不活性ガス下における有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ａ（２００Ａ）の製造》
　上記有機ＥＬ素子１００Ａの製造において、発光層の形成について発光層の形成における発光層形成用塗布液を下記のように変更し、ポリマー、ホスト化合物及び発光性ドーパントの固形分比率（質量部）を表ＩＩＩのように変更した以外は、同様な方法で有機ＥＬ素
子２００Ａを製造した。 [Example 2]
<Production of organic EL element under inert gas>
<<Production of Organic EL Element A (200A)>>
In the production of the organic EL element 100A, the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as follows, and the solid content ratio (parts by mass) of the polymer, the host compound, and the light-emitting dopant was changed to An organic EL device 200A was manufactured in the same manner except for the changes shown in Table III.
　〈発光層形成用塗布液〉
　ホスト化合物ＫＨ－１　　　　　　　　　　　　　１１．４質量部
　発光性ドーパントＢＤ－２　　　　　　　　　　　　３．６質量部
　プロピレングリコールモノメチルエーテルアセテート
　　　　　　　　　　　　　　　　　　　　　　　　２０００質量部 <Coating solution for forming light-emitting layer>
Host compound KH-1 11.4 parts by mass Luminous dopant BD-2 3.6 parts by mass Propylene glycol monomethyl ether acetate 2000 parts by mass
　《有機ＥＬ素子Ｈ（２００Ｈ、正孔移動度測定用）の製造》
　上記有機ＥＬ素子１００Ｈと同様にして正孔移動度測定用素子２００Ｈを製造した。 <<Manufacture of organic EL element H (200H, for hole mobility measurement)>>
A hole mobility measuring device 200H was manufactured in the same manner as the organic EL device 100H.
　《有機ＥＬ素子Ｅ（２００Ｅ、電子移動度測定用）の製造》
　上記有機ＥＬ素子１００Ｅと同様にして電子移動度測定用素子２００Ｅを製造した。 <<Manufacture of organic EL element E (200E, for electron mobility measurement)>>
An electron mobility measuring device 200E was manufactured in the same manner as the organic EL device 100E.
　《その他の有機ＥＬ素子Ａ、Ｈ及びＥの製造》
　上記不活性ガス下における有機ＥＬ素子２００Ａ、２００Ｈ及び２００Ｅの製造において、発光層の形成における発光層形成用塗布液のポリマーの種類を表IIIのように変更し、ポリマー、ホスト化合物及び発光性ドーパントの固形分比率（質量部）を表IIIのように変更した以外は、同様な方法で各有機ＥＬ素子Ａ（２０１Ａ～２１３Ａ）、Ｈ（２０１Ｈ～２１３Ｈ）及びＥ（２０１Ｅ～２１３Ｅ）を製造した。 <<Production of other organic EL elements A, H and E>>
In the production of the organic EL elements 200A, 200H and 200E under the inert gas, the type of polymer in the coating liquid for forming the light-emitting layer in the formation of the light-emitting layer was changed as shown in Table III, and the polymer, host compound and light-emitting dopant Each organic EL element A (201A to 213A), H (201H to 213H) and E (201E to 213E) were produced in the same manner except that the solid content ratio (parts by mass) of was changed as shown in Table III. .
　＜大気下での有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ｂ（２００Ｂ）の製造》
　上記不活性ガス下における有機ＥＬ素子２００Ａの製造において、発光層の成膜雰囲気を空気（湿度５０％）とした以外は、同様にして大気下製造有機ＥＬ素子２００Ｂを製造した。 <Production of organic EL element in air>
<<Production of organic EL element B (200B)>>
An organic EL element 200B was produced in the same manner as in the production of the organic EL element 200A under the inert gas, except that air (50% humidity) was used as the atmosphere for film formation of the light-emitting layer.
　《その他の有機ＥＬ素子Ｂの製造》
　上記大気下での有機ＥＬ素子２００Ｂの製造において、発光層の形成における発光層形成用塗布液のポリマーの種類を表IIIのように変更した以外は、同様な方法で各有機ＥＬ素子Ｂ（２０１Ｂ～２１３Ｂ）、Ｈ（２０１Ｈ～２１３Ｈ）及びＥ（２０１Ｅ～２１３Ｅ）を製造した。 <<Manufacturing of other organic EL elements B>>
In the manufacture of the organic EL element 200B under the atmosphere, each organic EL element B (201B) was manufactured in the same manner except that the type of polymer in the coating liquid for forming the light emitting layer in the formation of the light emitting layer was changed as shown in Table III. ~213B), H (201H-213H) and E (201E-213E) were prepared.
　≪評価方法≫
　上記各有機ＥＬ素子を［実施例１］と同様の方法によって評価した。
　評価結果は、表IIIに示す。 ≪Evaluation method≫
Each of the above organic EL devices was evaluated by the same method as in [Example 1].
Evaluation results are shown in Table III.
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000019
　表IIIから、青色リン光発光性ドーパントを使用したときにおいても、本発明の実施例の有機ＥＬ素子は、比較例の有機ＥＬ素子よりも、発光効率及び駆動寿命が優れており、かつ大気下製造時の性能低下抑制とを両立できることが分かる。 From Table III, even when a blue phosphorescent dopant is used, the organic EL devices of Examples of the present invention are superior to the organic EL devices of Comparative Examples in luminous efficiency and driving life, and It can be seen that both suppression of performance deterioration during manufacturing can be achieved.
　［実施例３］
　＜不活性ガス下における有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ａ（３００Ａ及び３０１Ａ）、有機ＥＬ素子Ｈ（３００Ｂ及び３０１Ｂ、正孔移動度測定用）、有機ＥＬ素子Ｅ（３００Ｂ及び３０１Ｂ、電子移動度測定用）の製造》
　上記有機ＥＬ素子１００Ａの製造において、発光層の形成について発光層の形成における発光層形成用塗布液を下記のように変更し、表IVに記載の条件に変更した以外は、同様な方法で有機ＥＬ素子Ａ（３００Ａ及び３０１Ａ）、Ｈ（３００Ｈ及び３０１Ｈ）、Ｅ（３００Ｈ及び３０１Ｈ）をそれぞれ製造した。 [Example 3]
<Production of organic EL element under inert gas>
<<Production of organic EL elements A (300A and 301A), organic EL elements H (300B and 301B, for hole mobility measurement), and organic EL elements E (300B and 301B, for electron mobility measurement)>>
In the manufacture of the organic EL device 100A, the organic EL element 100A was produced in the same manner except that the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as follows and the conditions were changed to those described in Table IV. EL elements A (300A and 301A), H (300H and 301H), and E (300H and 301H) were manufactured, respectively.
　〈発光層形成用塗布液〉
　ホスト化合物ＫＨ－２　　　　　　　　　　　　　１１．４質量部
　発光性ドーパントＢＤ－３　　　　　　　　　　　　３．６質量部
　プロピレングリコールモノメチルエーテルアセテート
　　　　　　　　　　　　　　　　　　　　　　　　２０００質量部 <Coating solution for forming light-emitting layer>
Host compound KH-2 11.4 parts by mass Luminescent dopant BD-3 3.6 parts by mass Propylene glycol monomethyl ether acetate 2000 parts by mass
　＜大気下製造下における有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ｂ（３００Ｂ及び３０１Ｂ）の製造》
　上記不活性ガス下における有機ＥＬ素子３００Ａ及び３０１Ａの製造において、発光層の成膜雰囲気を空気（湿度５０％）とした以外は、同様にして有機ＥＬ素子Ｂ（３００Ｂ及び３０１Ｂ）を製造した。 <Production of organic EL element under atmospheric production>
<<Manufacture of organic EL element B (300B and 301B)>>
Organic EL elements B (300B and 301B) were manufactured in the same manner as in the manufacture of the organic EL elements 300A and 301A under the inert gas, except that air (50% humidity) was used as the atmosphere for film formation of the light-emitting layer.
　≪評価方法≫
　上記各有機ＥＬ素子を［実施例１］と同様の方法によって評価した。
　評価結果は、表IVに示す。 ≪Evaluation method≫
Each of the above organic EL devices was evaluated by the same method as in [Example 1].
Evaluation results are shown in Table IV.
Figure JPOXMLDOC01-appb-T000020
Figure JPOXMLDOC01-appb-T000020
　表IVに示した結果から、本発明の有機ＥＬ素子は、ポリマーが立体規則性の異なる成分の混合物であることにより、発光効率及び駆動寿命が優れており、かつ大気下製造時の性能低下抑制とを更に両立できることが分かる。 From the results shown in Table IV, the organic EL device of the present invention has excellent luminous efficiency and drive life due to the fact that the polymer is a mixture of components with different stereoregularities, and suppresses performance deterioration during manufacturing in the atmosphere. and can be further compatible.
　［実施例４］
　＜不活性ガス下における有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ａ（４００Ａ）の製造》
　上記有機ＥＬ素子１００Ａの製造において、発光層の形成における発光層形成用塗布液を下記のように変更し、ポリマー、ホスト化合物及び発光性ドーパントの固形分比率（質量部）を表Ｖのように変更した以外は、同様な方法で有機ＥＬ素子４００Ａを製造した。 [Example 4]
<Production of organic EL element under inert gas>
<<Production of Organic EL Element A (400A)>>
In the production of the organic EL element 100A, the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as follows, and the solid content ratio (parts by mass) of the polymer, host compound, and light-emitting dopant was changed as shown in Table V. An organic EL device 400A was manufactured in the same manner except for the changes.
　〈発光層形成用塗布液〉
　ホスト化合物ＴＨ－１　　　　　　　　　　　　　１１．４質量部
　発光性ドーパントＧＤ－１　　　　　　　　　　　　３．６質量部
　プロピレングリコールモノメチルエーテルアセテート
　　　　　　　　　　　　　　　　　　　　　　　　２０００質量部 <Coating solution for forming light-emitting layer>
Host compound TH-1 11.4 parts by mass Luminous dopant GD-1 3.6 parts by mass Propylene glycol monomethyl ether acetate 2000 parts by mass
　《有機ＥＬ素子Ｈ（４００Ｈ、正孔移動度測定用）の製造》
　上記有機ＥＬ素子１００Ｈと同様にして正孔移動度測定用素子４００Ｈを製造した。 <<Manufacture of organic EL element H (400H, for hole mobility measurement)>>
A hole mobility measuring device 400H was manufactured in the same manner as the organic EL device 100H.
　《有機ＥＬ素子Ｅ（４００Ｅ、電子移動度測定用）の製造》
　上記有機ＥＬ素子１００Ｅと同様にして電子移動度測定用素子４００Ｅを製造した。 <<Manufacture of organic EL element E (400E, for electron mobility measurement)>>
An electron mobility measuring device 400E was manufactured in the same manner as the organic EL device 100E.
　《その他の有機ＥＬ素子Ａ、Ｈ及びＥの製造》
　上記不活性ガス下における有機ＥＬ素子４００Ａ、４００Ｈ及び４００Ｅの製造において、発光層の形成における発光層形成用塗布液のポリマーの種類を表Vのように変更し、ポリマー、ホスト化合物及び発光性ドーパントの固形分比率（質量部）を表Ｖのように変更した以外は、同様な方法で各有機ＥＬ素子Ａ（４０１Ａ～４０７Ａ）、Ｈ（４０１Ｈ～４０７Ｈ）及びＥ（４０１Ｅ～４０７Ｅ）を製造した。 <<Production of other organic EL elements A, H and E>>
In the production of the organic EL elements 400A, 400H and 400E under the inert gas, the type of polymer in the coating solution for forming the light-emitting layer in the formation of the light-emitting layer was changed as shown in Table V, and the polymer, host compound and light-emitting dopant Each organic EL element A (401A to 407A), H (401H to 407H) and E (401E to 407E) were produced in the same manner except that the solid content ratio (parts by mass) of was changed as shown in Table V. .
　＜大気下での有機ＥＬ素子の製造＞
　《有機ＥＬ素子Ｂ（４００Ｂ）の製造》
　上記不活性ガス下における有機ＥＬ素子４００Ａの製造において、発光層の成膜雰囲気を空気（湿度５０％）とした以外は、同様にして大気下製造有機ＥＬ素子４００Ｂを製造した。 <Production of organic EL element in air>
<<Manufacture of organic EL element B (400B)>>
Organic EL element 400B was produced in the same manner as in the production of organic EL element 400A under the inert gas, except that air (50% humidity) was used as the atmosphere for film formation of the light-emitting layer.
　《その他の有機ＥＬ素子Ｂの製造》
　上記大気下での有機ＥＬ素子４００Ｂの製造において、発光層の形成における発光層形成用塗布液のポリマーの種類を表Ｖのように変更した以外は、同様な方法で各有機ＥＬ素子Ｂ（４０１Ｂ～４０７Ｂ）、Ｈ（４０１Ｈ～４０７Ｈ）及びＥ（４０１Ｅ～４０７Ｅ）を製造した。 <<Manufacturing of other organic EL elements B>>
In the manufacture of the organic EL element 400B under the atmosphere, each organic EL element B (401B ~407B), H (401H-407H) and E (401E-407E) were prepared.
　≪評価方法≫
　上記各有機ＥＬ素子を［実施例１］と同様の方法によって評価した。
　評価結果は、表Vに示す。 ≪Evaluation method≫
Each of the above organic EL devices was evaluated by the same method as in [Example 1].
Evaluation results are shown in Table V.
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000021
　表Vから、発光層中のポリマー、ホスト化合物及び発光性ドーパントの固形分比率を変えたときにおいても、実施例の有機ＥＬ素子は、比較例の有機ＥＬ素子よりも、発光効率及び駆動寿命が優れており、かつ大気下での製造時の性能低下抑制とを更に両立できることが分かる。 From Table V, even when the solid content ratios of the polymer, host compound, and luminescent dopant in the light-emitting layer were changed, the organic EL devices of Examples exhibited higher luminous efficiency and driving life than the organic EL devices of Comparative Examples. It can be seen that it is possible to achieve both excellent performance and suppression of performance deterioration during production in the atmosphere.
　（まとめ）
　上記結果から、発光層に含有させる電荷輸送性ホスト化合物、発光性ドーパント及ポリマー等により、正孔移動度と電子移動度の差を制御することにより、本発明の課題を解決できることが分かる。
　すなわち、発光効率が高く、長寿命で、かつ、大気下での製造時の性能低下を抑制可能であり、低コストにて製造可能である有機エレクトロルミネッセンス素子及びその製造方法、並びに照明装置及び表示装置を提供することができる。 (summary)
From the above results, it can be seen that the problems of the present invention can be solved by controlling the difference between the hole mobility and the electron mobility with the charge-transporting host compound, the light-emitting dopant, the polymer, etc. contained in the light-emitting layer.
That is, an organic electroluminescence element that has high luminous efficiency, has a long life, can suppress performance deterioration during manufacturing in the atmosphere, and can be manufactured at low cost, a method for manufacturing the same, a lighting device, and a display Equipment can be provided.
　発光効率が高く、長寿命で、かつ、大気下での製造時の性能低下を抑制可能であり、低コストにて製造可能である有機エレクトロルミネッセンス素子及びその製造方法、並びにそれを具備した照明装置、表示装置及び印刷造形物を提供することができる。 An organic electroluminescence element that has high luminous efficiency, has a long life, can suppress deterioration in performance during manufacturing in the atmosphere, and can be manufactured at low cost, a method for manufacturing the same, and a lighting device equipped with the same , a display device and a printed model can be provided.
　１、１１　基板
　２　バンク、絶縁層
　２ａ　バンクの凹部
　２ｂ　バンクの凸部
　１０　有機ＥＬ素子（発光画像部）
　１２　陽極
　１３　正孔注入層
　１４　正孔輸送層
　１５　発光層
　１６　電子輸送層
　１７　電子注入層
　１８　陰極
　２１　青色（Ｂ）発光画素
　２２　緑色（Ｇ）発光画素
　２３　赤色（Ｒ）発光画素
　１００　ラインヘッド型のヘッドユニット
　１０１　搬送機構
　１０２、１０３、１０４　色相の異なるインクを吐出するヘッド
　Ｎ　ノズル
　Ｈ　ヘッド
　ＨＵ　ヘッドユニット REFERENCE SIGNS LIST 1, 11 Substrate 2 Bank, insulating layer 2a Concave portion of bank 2b Convex portion of bank 10 Organic EL element (luminescence image portion)
12 Anode 13 Hole injection layer 14 Hole transport layer 15 Light emitting layer 16 Electron transport layer 17 Electron injection layer 18 Cathode 21 Blue (B) light emitting pixel 22 Green (G) light emitting pixel 23 Red (R) light emitting pixel 100 Line head type head unit 101 transport mechanism 102, 103, 104 head for ejecting inks of different hues N nozzle H head HU head unit

Claims (18)

  1. 　少なくとも基板上に、対向する陽極と陰極に挟持された画像表示部とを有する有機エレクトロルミネッセンス素子であって、
    　前記画像表示部が、発光画像表示部と非発光画像表示部で構成され、
    　前記発光画像表示部が、少なくとも電極、電荷注入層又は電荷輸送層に隣接する発光層を有し、
    　前記発光層が、少なくとも導電率が１［Ｓ／ｍ］以下のポリマー、電荷輸送性ホスト化合物及び発光性ドーパントを含有し、かつ、
    　前記発光層の正孔移動度と電子移動度の常用対数値の差の絶対値が、４．５以下である
    ことを特徴とする有機エレクトロルミネッセンス素子。     An organic electroluminescence element having an image display portion sandwiched between an anode and a cathode facing each other on at least a substrate,
    wherein the image display section is composed of a luminescent image display section and a non-luminescent image display section,
    the light-emitting image display section has at least a light-emitting layer adjacent to an electrode, a charge injection layer, or a charge transport layer;
    The light-emitting layer contains at least a polymer having a conductivity of 1 [S/m] or less, a charge-transporting host compound, and a light-emitting dopant, and
    An organic electroluminescence device, wherein the absolute value of the difference between the common logarithms of hole mobility and electron mobility in the light-emitting layer is 4.5 or less.
  2. 　前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が、３．５以下である
    ことを特徴とする請求項１に記載の有機エレクトロルミネッセンス素子。     2. The organic electroluminescence device according to claim 1, wherein the absolute value of the difference between the common logarithms of the hole mobility and the electron mobility of the light-emitting layer is 3.5 or less.
  3. 　前記発光層の正孔移動度と電子移動度の常用対数の差の絶対値が、２．５以下である
    ことを特徴とする請求項１又は請求項２に記載の有機エレクトロルミネッセンス素子。     3. The organic electroluminescence device according to claim 1, wherein the absolute value of the difference between the common logarithms of the hole mobility and the electron mobility of the light-emitting layer is 2.5 or less.
  4. 　前記発光層の総質量を１００とした場合の前記ポリマーの質量比率が、５～８０質量％の範囲内である
    ことを特徴とする請求項１から請求項３までのいずれか一項に記載の有機エレクトロルミネッセンス素子。     4. The method according to any one of claims 1 to 3, wherein the mass ratio of the polymer is in the range of 5 to 80% by mass when the total mass of the light emitting layer is 100. Organic electroluminescence device.
  5. 　前記ポリマーが、ベンゼン環を含むポリマーである
    ことを特徴とする請求項１から請求項４までのいずれか一項に記載の有機エレクトロルミネッセンス素子。     5. The organic electroluminescence device according to any one of claims 1 to 4, wherein the polymer is a polymer containing benzene rings.
  6. 　前記ベンゼン環を含むポリマーが、非共役ポリマーである
    ことを特徴とする請求項５に記載の有機エレクトロルミネッセンス素子。     6. The organic electroluminescence device according to claim 5, wherein the polymer containing benzene rings is a non-conjugated polymer.
  7. 　前記非共役ポリマーが、ベンゼン環を側鎖として含む
    ことを特徴とする請求項６に記載の有機エレクトロルミネッセンス素子。     7. The organic electroluminescence device according to claim 6, wherein the non-conjugated polymer contains benzene rings as side chains.
  8. 　前記非共役ポリマーが、ポリスチレンである
    ことを特徴とする請求項６又は請求項７に記載の有機エレクトロルミネッセンス素子。     8. The organic electroluminescence device according to claim 6, wherein said non-conjugated polymer is polystyrene.
  9. 　前記非共役ポリマーが、ポリスチレン誘導体である
    ことを特徴とする請求項６又は請求項７に記載の有機エレクトロルミネッセンス素子。     8. The organic electroluminescence device according to claim 6, wherein said non-conjugated polymer is a polystyrene derivative.
  10. 　前記ポリスチレン誘導体が、ポリビニルフェノールである
    ことを特徴とする請求項９に記載の有機エレクトロルミネッセンス素子。     10. The organic electroluminescence device according to claim 9, wherein said polystyrene derivative is polyvinylphenol.
  11. 　前記非共役ポリマーが、立体規則性の異なる成分の混合物である
    ことを特徴とする請求項６から請求項１０までのいずれか一項に記載の有機エレクトロルミネッセンス素子。     11. The organic electroluminescence device according to any one of claims 6 to 10, wherein the non-conjugated polymer is a mixture of components with different stereoregularities.
  12. 　前記発光層が、電荷注入層に直接隣接する
    ことを特徴とする請求項１から請求項１１までのいずれか一項に記載の有機エレクトロルミネッセンス素子。     12. The organic electroluminescence device according to any one of claims 1 to 11, wherein the light emitting layer is directly adjacent to the charge injection layer.
  13. 　前記発光層が、電極に直接隣接する
    ことを特徴とする請求項１から請求項１２までのいずれか一項に記載の有機エレクトロルミネッセンス素子。     13. The organic electroluminescence device according to any one of claims 1 to 12, wherein the light-emitting layer is directly adjacent to the electrode.
  14. 　請求項１から請求項１３までのいずれか一項に記載の有機エレクトロルミネッセンス素子を製造する有機エレクトロルミネッセンス素子の製造方法であって、
    　前記発光層を、インクジェット印刷法によって形成する工程を有する
    ことを特徴とする有機エレクトロルミネッセンス素子の製造方法。     A method for manufacturing an organic electroluminescence device for manufacturing the organic electroluminescence device according to any one of claims 1 to 13,
    A method for producing an organic electroluminescence device, comprising a step of forming the light-emitting layer by an inkjet printing method.
  15. 　前記発光層を、大気下で、インクジェット印刷法によって形成する工程を有する
    ことを特徴とする請求項１４に記載の有機エレクトロルミネッセンス素子の製造方法。     15. The method of manufacturing an organic electroluminescence device according to claim 14, further comprising forming the light-emitting layer by an inkjet printing method in the atmosphere.
  16. 　請求項１から請求項１３までのいずれか一項に記載の有機エレクトロルミネッセンス素子を備えている
    ことを特徴とする照明装置。     A lighting device comprising the organic electroluminescence device according to claim 1 .
  17. 　請求項１から請求項１３までのいずれか一項に記載の有機エレクトロルミネッセンス素子を備えている
    ことを特徴とする表示装置。     A display device comprising the organic electroluminescence element according to any one of claims 1 to 13.
  18. 　請求項１から請求項１２までのいずれか一項に記載の有機エレクトロルミネッセンス素子を備えている
    ことを特徴とする印刷造形物。     A printed product comprising the organic electroluminescence element according to any one of claims 1 to 12.
PCT/JP2021/046667 2021-01-29 2021-12-17 Organic electroluminescent element, method for producing same, lighting device provided with same, display device and printed model WO2022163199A1 (en)

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