JP2001052869A - Organic electroluminescent device - Google Patents

Abstract

(57) [Problem] To provide an organic EL element that emits red light with good color purity and an application of the organic EL element. An organic EL device using a quinolinol metal complex as a guest compound in a light-emitting layer, wherein a specific pyrane derivative is added as a guest compound in an amount of more than 0.1 mol% and less than 10 mol% based on the quinolinol metal complex. The problem is solved by providing an organic EL element that emits light in the red region, and an information display device and a light emitting device using the organic EL element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device (hereinafter abbreviated as "organic EL device"), and more particularly, to an organic EL device which emits red light having good color purity. .

[0002]

2. Description of the Related Art In the field of information display, an electroluminescent device has been spotlighted as a next-generation display device. Current,
In a relatively large information display device such as a computer terminal or a television receiver, a cathode ray tube is mainly used. However, since the CRT is large in volume and weight and has a high operating voltage, it is not suitable for consumer devices and small devices that emphasize portability. There is a need for smaller devices that are thinner, lighter, flat, have lower operating voltages, and consume less power. At present, a liquid crystal element has a low operating voltage and a relatively low power consumption, and is frequently used in various fields. However, an information display device using a liquid crystal element changes contrast depending on the viewing angle, so that a clear display cannot be obtained unless the image is read within a certain angle range, and a backlight is usually required. There is a problem that it does not become so small. An organic EL element has emerged as a display element that solves these problems.

[0003] An organic EL device usually has a light-emitting layer containing a light-emitting compound interposed between an anode and a cathode, and a direct-current voltage is applied between the anode and the cathode to form holes in the light-emitting layer. A light-emitting element that uses light emission such as fluorescence or phosphorescence emitted when the excited state returns to the ground state by creating an excited state of the luminescent compound by injecting electrons and recombining them with each other. is there. Organic EL elements
In forming the light-emitting layer, a characteristic feature is that the color tone of light emission can be appropriately changed by selecting an appropriate organic compound as a host compound and changing a guest compound (dopant) combined with the host compound. is there. Further, depending on the combination of the host compound and the guest compound, there is a possibility that the luminance and the lifetime of light emission can be significantly improved. In the first place, an organic EL element emits light by itself, and an information display device using the organic EL element has an advantage that it has no viewing angle dependence and does not require a backlight, so that power consumption can be reduced. Is said to be.

However, in organic EL devices that emit light in the green range, improvements in luminous efficiency and emission spectrum by the addition of a guest compound have been reported. However, organic EL devices that emit light in the red range have not been reported. Since no effective guest compound has been found, not only the color purity and luminance but also the durability and the reliability are still insufficient. For example, JP-A-10-
The organic EL devices disclosed in Japanese Patent No. 6042 and U.S. Pat. No. 4,769,292 have low luminance and do not emit pure red light, so that there is still a problem in realizing full color. I can't get it.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to provide an organic E which emits red light with good color purity.
An object of the present invention is to provide an L element and its use.

[0006]

Means for Solving the Problems In order to solve these problems, the inventors of the present invention have made intensive studies and searched, and as a result, obtained through a step of reacting a compound having a 3-formylmarin skeleton with dehydroacetic acid. A series of pyran derivatives that can be obtained are mixed with an organic EL device using a quinolinol metal complex as a host compound in an amount of more than 0.1 mol% and less than 10 mol% with respect to the quinolinol metal complex as a guest compound, to obtain color purity. It emits red light with good brightness. Moreover, such an organic EL device is
It has also been found that the light-emitting device has high luminance and a long life, and is extremely useful as a display element in various kinds of information display devices. The present invention is based on the creation of a novel pyran derivative and the discovery of its industrially useful properties.

That is, the present invention has been made to solve the above-mentioned problem by providing an organic EL device using a quinolinol metal complex as a host compound in a light-emitting layer, as a guest compound,
The problem is solved by providing an organic EL light emitting device which emits light in the red region, in which the pyran derivative represented by Chemical Formula 1 is mixed in an amount of more than 0.1 mol% and less than 10 mol% with respect to the quinolinol metal complex. It is.

[0008]

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In the chemical formula ₁ , R ₁ and R ₂ each independently represent a hydrogen atom, an alkenyl group, an aryl group or a linear or branched alkyl group, and the aryl group and the alkyl group each represent a substituent. You may have. R
₃ represents a hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a monovalent group derived from a carboxyl group or a linear or branched alkyl group, and the alkyl group may have a substituent. Note that R ₁ and / or R
₂ may include a nitrogen atom to which they are bonded, or may form a cyclic structure including the nitrogen atom and a benzene ring to which the nitrogen atom is bonded.

The present invention solves the above-mentioned problem by providing an information display device using such an organic EL element.

Further, the present invention solves the above problem,
The problem is solved by providing a luminous body using such an organic EL element.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an organic EL device using a quinolinol metal complex as a host compound in a light emitting layer.
In the light-emitting element, the pyran derivative represented by Chemical Formula 1 is used as a guest compound in an amount of 0.1 to 0.1% with respect to the quinolinol metal complex.
The present invention relates to an organic EL light-emitting device that emits light in a red region, which is mixed in an amount of more than 10 mol% and less than 10 mol%.

In the chemical formula 1, R ₁ and R ₂ each independently represent a hydrogen atom, an alkenyl group, an aryl group or a linear or branched alkyl group, and the aryl group and the alkyl group each represent a substituent. You may have. R
_{When 1} and / or R ₂ is an alkyl group, the chain length is usually selected from the group having up to 20 carbon atoms, preferably from 1 to 18 carbon atoms. As individual alkyl groups,
For example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, isobutyl group, sec
-Butyl group, tert-butyl group, pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1
-Methylpentyl, 2-methylpentyl, hexyl, isohexyl, 5-methylhexyl, heptyl, octyl, nonyl, decyl, dodecyl, octadecyl and the like. Examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 2-propenyl group, an isopropenyl group, a 3-butenyl group, and a 1,3-
Butadienyl group, 2-pentenyl group and the like, and examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a biphenyl group, a naphthyl group, an anthryl group and a phenanthryl group. Examples of the substituent for the alkyl group and the aryl group include alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group;
Carboxyl group, alkyl carboxyl group, alkoxy carboxyl group, sulfonyl group, alkylsulfonyl group, organic acid group such as aminosulfonyl group, phenyl group,
Aryl groups such as tolyl group, xylyl group, biphenyl group, naphthyl group, anthryl group, phenanthryl group, cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cycloheptyl group, phenylmethyl group, 4-butylphenylmethyl group, 4- Butoxyphenylmethyl group, 2
-Hydroxyethyl group, 2- (2-ethoxy) ethoxyethyl group, 2-butoxyethyl group, 2-carboxylethyl group, 2-cyanoethyl group, 4-sulfoxybutyl group, 3-sulfoxypropyl group, 6- And substituted alkyl groups such as bromohexyl group. Note that R ₁ and / or
Or R ₂ contains the nitrogen atom to which they are attached,
For example, a morphonyl group, a piperidinyl group, a 5-membered ring including a pyrrolidinyl group, or a cyclic structure such as a 6-membered ring, or a 5-membered ring including a benzene ring to which the nitrogen atom is bonded, A cyclic structure such as a six-membered ring may be formed.

Further, in the chemical formula 1, R ₃ is a hydrogen atom, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group. Group, isobutyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1-methylpentyl group, 2-
Methylpentyl group, cyclopentyl group, hexyl group, isohexyl group, alkyl group having up to 6 carbon atoms such as cyclohexyl group, carboxyl group or alkoxycarboxyl group, acyl group, represents a monovalent group derived from a carboxyl group such as an amide group, The alkyl group may have one or more substituents such as a fluorine atom. Examples of the pyran derivative represented by Chemical Formula 1 include compounds represented by Chemical Formulas 2 to 13.

[0015]

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[0016]

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[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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The pyran derivative used in the present invention can be prepared by various methods. If emphasis is placed on economics, a method of reacting a compound having a 3-formylmarin skeleton represented by Chemical Formula 14 having R ₁ , R ₂ and R ₃ corresponding to Chemical Formula ₁ with dehydroacetic acid is known. It is suitable. That is, first, a compound represented by Chemical formula 14 is prepared according to the method described in JP-A-8-95243, and then dehydroacetic acid is added thereto, and in a non-aqueous solvent, for example, piperidine, triethylamine, N, N-
By heating in the presence of a basic catalyst such as dimethylaniline or pyridine, a pyran derivative represented by the formula 1 is obtained. The desired amount of any of the pyran derivatives represented by Chemical Formulas 2 to 13 can be easily prepared by this method.

[0028]

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The pyran derivative thus obtained is usually
Prior to use, for example, separation, gradient, filtration, extraction, concentration, thin-layer chromatography, column chromatography, gas chromatography, high-performance liquid chromatography, distillation, sublimation, purification of related compounds such as crystallization Purification is carried out by a common method generally used, and if necessary, these methods are applied in combination. The pyran derivative used as the guest compound in the present invention depends on the type of the pyran derivative and the use of the organic EL device,
Prior to use, it is desirable to purify at least by distillation, crystallization and / or sublimation.

The quinolinol metal complex referred to in the present invention is:
It includes all metal complexes that can be used as a host compound in an organic EL device by using quinolinols as ligands. Preferred quinolinol metal complexes are metal complexes having 8-quinolinols as ligands, such as aluminum,
It is desirable to use metals such as zinc, beryllium, magnesium, indium, lithium, gallium, and calcium or oxides of these metals as central atoms.
In addition, 8-quinolinols as ligands include, for example, a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom, a methyl group, an ethyl group, and a propyl group at a site other than the 8-position to which a hydroxyl group is bonded. Or an alkoxy group such as an alkyl group, a methoxy group, an ethoxy group, a propoxy group, or a substituent such as a haloalkyl group, a cyano group, a nitro group, a sulfonyl group, or a carboxylic acid ester group. Good.

Examples of the individual quinolinol metal complexes include, for example, aluminum tris (8-quinolinolate), aluminum tris (3,4-dimethyl-8-quinolinolate), aluminum tris (4-methyl-8-quinolinolate), aluminum tris (4 -Methoxy-8-quinolinolate) aluminum, tris (4,5-dimethyl-8-quinolinolate) aluminum, tris (4,6-dimethyl-8-quinolinolate) aluminum, tris (5-
Chloro-8-quinolinolate) aluminum, tris (5-bromo-8-quinolinolate) aluminum, tris (5,7-dichloro-8-quinolinolate) aluminum, tris (5-cyano-8-quinolinolate) aluminum, tris (5- Aluminum complexes such as sulfonyl-8-quinolinolate) aluminum, tris (7-propyl-8-quinolinolate) aluminum, bis (2-methyl-8-quinolinolate) aluminum oxide, bis (8-quinolinolate) zinc, bis (2-
Methyl-8-quinolinolate) zinc, bis (2,4-dimethyl-8-quinolinolate) zinc, bis (2-methyl-5-chloro-8-quinolinolate) zinc, bis (2-
Methyl-5-cyano-8-quinolinolate) zinc, bis (3,4-dimethyl-8-quinolinolate) zinc, bis (4,6-dimethyl-8-quinolinolate) zinc, bis (5-chloro-8-quinolinolate) Zinc, screw (5
Zinc complexes such as 7-dichloro-8-quinolinolate) zinc, bis (8-quinolinolate) beryllium, bis (2
-Methyl-8-quinolinolate) beryllium, bis (2,4-dimethyl-8-quinolinolate) beryllium, bis (2-methyl-5-chloro-8-quinolinolate) beryllium, bis (2-methyl-5-cyano-quinolinolate) ) Beryllium, bis (3,4-dimethyl-8)
-Quinolinolate) beryllium, bis (4,6-dimethyl-8-quinolinolate) beryllium, bis (5-chloro-8-quinolinolate) beryllium, bis (5,7-
Beryllium complexes such as dichloro-8-quinolinolate) beryllium, bis (8-quinolinolate) magnesium, bis (2-methyl-8-quinolinolate) magnesium, bis (2,4-dimethyl-8-quinolinolate)
Magnesium, bis (2-methyl-5-chloro-8-quinolinolate) magnesium, bis (2-methyl-5-
Cyano-8-quinolinolate) magnesium, bis (3,4-dimethyl-8-quinolinolate) magnesium, bis (4,6-dimethyl-8-quinolinolate) magnesium, bis (5-chloro-8-quinolinolate)
Magnesium complexes such as magnesium and bis (5,7-dichloro-8-quinolinolate) magnesium; indium complexes such as tris (8-quinolinolate) indium; gallium complexes such as tris (5-chloro-8-quinolinolate) gallium; Examples thereof include calcium complexes such as 5-chloro-8-quinolinolate) calcium, but these are merely examples, and the quinolinol metal complex referred to in the present invention should not be limited to these. When the quinolinol metal complex has two or more ligands in the molecule, these ligands may be the same or different.

The organic EL device of the present invention is essentially an organic EL device using such a quinolinol metal complex as a host compound, and usually comprises an anode for applying a positive voltage, a cathode for applying a negative voltage, A light emitting layer for recombining holes and electrons to extract light emission, and, if necessary, a hole injection / transport layer for injecting and transporting holes from the anode, and an electron injection for injecting and transporting electrons from the cathode. Single layer and stacked organic EL elements provided with a / transport layer are important application targets. The pyran derivative according to the present invention forms a stable thin film in a glassy state and, in an organic EL device using a host compound, has a remarkable property of shifting the light emission of the organic EL device to a red region. It is extremely useful as a guest compound of an organic EL device aiming at good red light. The organic EL device of the present invention, which is used in combination with such a pyran derivative and a quinolinol metal complex, has a color purity of substantially no emission of a wavelength of 550 nm or less due to the quinolinol metal complex when the anode is set at a high potential with respect to the cathode. Emit good red light. The organic E of the present invention
In the L element, the quinolinol metal complex and / or the pyran derivative have a hole injecting / transporting ability and / or an electron injecting / transporting ability, or one of the hole injecting / transporting layer material and the electron injecting / transporting layer material is When having the other function, the electron injection / transport layer or the hole injection / transport layer may be omitted.

The organic EL device of the present invention is usually constituted such that the light emitting layer contains the quinolinol metal complex and the pyran derivative, respectively, and if necessary, two or more quinolinol metal complexes and / or pyran derivatives are used. Used in combination. The amount of the pyran derivative relative to the quinolinol metal complex depends on the type of the quinolinol metal complex, but is usually in the range of more than 0.1 mol% and less than 10 mol%, preferably 0.5 to 5 mol%. ,
More preferably, a range of 1 to 3 mol% is selected.
When the compounding ratio of the pyran derivative is 0.1 mol% or less, the luminescence of the quinolinol metal complex itself is not suppressed.
When the content is 0 mol% or more, the emission intensity of the pyran derivative decreases.

As described above, the organic EL device of the present invention can be configured as a single layer type or a stacked type. The operation of an organic EL element is essentially a process of injecting electrons and holes from an electrode, a process of moving electrons and holes through a solid,
Electrons and holes recombine to generate singlet or triplet excitons, and the excitons emit light. These processes are performed in both single-layer and stacked organic EL devices. There is essentially no difference. However, in the single-layer organic EL device, the characteristics of the above four steps can be improved only by changing the molecular structure of the light-emitting compound, whereas in the stacked organic EL device,
In general, it is better to configure a stacked type rather than a single layer type, since the functions required in each process can be shared among multiple materials and each material can be optimized independently. However, it is easy to achieve the expected performance.

Therefore, the organic EL device of the present invention
Further description will be given by taking a stacked organic EL element as an example. FIG. 1 is a schematic view of a stacked organic EL element of the present invention,
In the figure, reference numeral 1 denotes a substrate, which is generally made of glass such as soda glass, barium silicate glass, or aluminosilicate glass, or a general-purpose substrate material such as plastic or ceramic. Preferred substrate materials are transparent glass and plastic, and opaque ceramics such as silicon are used in combination with transparent electrodes.

Reference numeral 2 denotes an anode, which is usually brought into close contact with one side of the substrate 1 by a method such as vacuum evaporation, chemical vapor deposition (CVD), or sputtering, and has an electrically low resistivity and is completely visible. A metal or a conductive compound having a large light transmittance over a region is formed to a thickness of 10 to 1,000 nm, preferably, so that the resistivity at the anode 2 is 1 kΩ / □.
It is formed by forming a film with a thickness of 50 to 500 nm. As such a conductive material, usually, metals such as gold, platinum, aluminum, and nickel, tin oxide, indium oxide, and a mixed system of tin oxide and indium oxide (hereinafter referred to as “IT
O ". ), Or a conductive oligomer or polymer having aniline, thiophene, pyrrole or the like as a repeating unit. this house,
ITO has a feature that a material having a low resistivity can be easily obtained and a fine pattern can be easily formed by etching with an acid.

Reference numeral 3 denotes a hole injection / transport layer, which is usually an anode
2 in the same manner as in 2,
The material for the hole injection / transport layer is formed to a thickness of 1 to 1,000 nm.
It is formed by filming. Material for hole injection / transport layer
To facilitate the injection and transport of holes from the anode 2
In order to minimize the ionization potential, ^Four
To 10⁶Under an electric field of V / cm, at least 10
^-6cm^Two/ V · s exhibiting hole mobility is desirable
No. Organic EL elements are used as materials for each hole injection / transport layer.
Commonly used in children, for example, aromatic tertiary amines,
Styrylamine, triazole derivative, oxadiazo
Derivatives, imidazole derivatives, polyarylalkanes
Derivatives, pyrazoline derivatives, pyrazolone derivatives, phenyl
Diamine derivatives, arylamine derivatives, amine substitution
Substituted chalcone derivatives, oxazole derivatives, styrylane
Toracene derivative, fluorenone derivative, hydrazone derivative
Body, a stilbene derivative, and the like.
These are used in combination.

Reference numeral 4 denotes a light-emitting layer, which is usually brought into close contact with the hole injecting / transporting layer 3 in the same manner as in the anode 2 to separate the quinolinol metal complex and the pyran derivative according to the present invention into a single layer or two layers. 10 to 1,000
It is formed by forming a film to a thickness of 0 nm, preferably 10 to 200 nm.

Reference numeral 5 denotes an electron injecting / transporting layer, which is usually an organic compound having a high electron affinity and closely absorbing the light emitting layer 4 in the same manner as in the anode 2, and does not absorb light in the red region. For example, the same compound as in the light-emitting layer 4 or a cyclic ketone such as benzoquinone, anthraquinone, or fluorenone or a derivative thereof, a silazane derivative, and further, a conductive oligomer or polymer having a repeating unit of aniline, thiophene, pyrrole, or the like. 1
Alternatively, it is formed by forming a plurality of layers to a thickness of 10 to 500 nm. When a plurality of materials for the electron injection / transport layer are used, even if the plurality of materials for the electron injection / transport layers are uniformly mixed to form a single layer, the materials for the electron injection / transport layer are not mixed but are mixed for each material for the electron injection / transport layer. It may be formed in a plurality of adjacent layers.

Reference numeral 6 denotes a cathode which is usually in close contact with the electron injecting / transporting layer 5 and has a work function lower than that of the compound used in the electron injecting / transporting layer 5 (usually 6 eV or less), for example, lithium, magnesium, It is formed by vapor deposition of a metal or metal oxide such as calcium, sodium, lithium, silver, copper, aluminum and indium, or a conductive compound alone or in combination. The thickness of the cathode 6 is not particularly limited, and is usually 10 nm or more, preferably, 10 nm or more so that the resistivity is 1 kΩ / □ or less, in consideration of conductivity, manufacturing cost, overall device thickness, light transmittance, and the like. , 50 to 500 nm. In order to enhance the adhesion between the cathode 6 and the electron injection / transport layer 5 containing an organic compound, for example, an aromatic diamine compound, a quinacridone compound, a naphthacene compound, an organic silicon compound may be used. And an interface layer containing an organic phosphorus compound or the like.

As described above, the organic EL device of the present invention
An anode 2, a cathode 6, a light emitting layer 4 and, if necessary, a hole injection / transport layer 3 and an electron injection / transport layer 5 on a substrate 1.
Can be obtained by forming them integrally while adhering to adjacent layers. In forming each layer, in order to minimize oxidation and decomposition of organic compounds and further adsorption of oxygen and moisture, under high vacuum, in detail,
It is desirable to work consistently at 10 ^-5 Torr or less. In forming the light-emitting layer, a quinolinol metal complex and a pyran derivative are mixed in advance at a predetermined ratio, or by controlling the heating rates of both in vacuum deposition independently of each other. The mixing ratio of the two to be deposited on the light emitting layer is adjusted. Organic E thus constructed
L element, in order to minimize the deterioration in the use environment, to partially or entirely the element, for example, sealed with a sealing glass or a metal cap under an inert gas atmosphere, or by using an ultraviolet curable resin It is desirable to cover with a protective layer.

The method of using the organic EL device according to the present invention will be described. The organic EL device according to the present invention applies a relatively high pulse voltage intermittently or a relatively low voltage depending on the application. Driving is performed by continuously applying a non-pulse voltage (usually 3 to 50 V). The organic EL device of the present invention emits light only when the potential of the anode is higher than the potential of the cathode. Therefore, the organic E of the present invention
The voltage applied to the L element may be DC or AC, and the waveform and period of the applied voltage may be appropriate. When an alternating current is applied, the organic EL device of the present invention:
In principle, the luminance repeatedly increases and decreases or blinks repeatedly according to the waveform and cycle of the applied alternating current. In the case of the organic EL device shown in FIG. 1, when a voltage is applied between the anode 2 and the cathode 3, the anode 2
From the cathode 6 reach the light-emitting layer 4 via the hole injection / transport layer 3, and electrons injected from the cathode 6 reach the light-emitting layer 4 via the electron injection / transport layer 5. as a result,
In the light emitting layer 4, recombination of holes and electrons occurs, and the desired red light is emitted from the excited pyran derivative through the anode 2 and the substrate 1. The organic EL device of the present invention generally has a light emission maximum in a red region having a wavelength of 600 to 670 nm, preferably 620 to 660 nm, although it depends on a quinolinol metal complex and a pyran derivative used in combination. In addition, the light emission is generally such that x is in the range of 0.50 to 0.72 and y is 0.20 to 0.36 on the xy chromaticity diagram.
In the range.

Since the organic EL device of the present invention has good color purity of light emission in the red region and excellent light emission efficiency and durability, it can be used in a variety of light emitting devices and information display devices for visually displaying information. Has a variety of uses. Since the light-emitting body using the organic EL element of the present invention as a light source has low power consumption and can be formed into a light-weight flat plate, in addition to a light source for general illumination, for example, a liquid crystal element, a copying apparatus,
Printing equipment, electrophotographic equipment, computers and their applied equipment, industrial control equipment, electronic measurement equipment, analytical equipment, general instruments, communication equipment, medical electronic measurement equipment, equipment mounted on automobiles, ships, aircraft, spacecraft, etc. Aircraft control equipment,
It is useful as an energy-saving and space-saving light source for interiors, signs and signs. When the organic EL device of the present invention is used for an information display device such as a computer, a television, a video, a game, a clock, a car navigation, an oscilloscope, a radar, and a sonar, the organic EL device emits light alone or in a green region or a blue region. Organic E
The driving is performed by applying a general-purpose simple matrix system or an active matrix system as needed while combining with the L element.

Hereinafter, with respect to the embodiments of the present invention, first, the preparation of the pyran derivative used in the present invention will be described in a reference example, and then, in an example, an organic EL device using the pyran derivative will be described.

[0045]

REFERENCE EXAMPLE <Pyran derivative> 3.09 g of dehydroacetic acid and a compound 5.02 represented by Chemical Formula 15 obtained by a known method.
g was dissolved in 20 ml of chloroform.
After the mixture was heated and refluxed for 4 hours, the reaction product was cooled to room temperature, concentrated, and the precipitated crystals were collected by filtration. When these crystals were recrystallized with an ethanol / acetone mixture,
The dark green crystal of the pyran derivative represented by Chemical Formula 12 is 1.02
g were obtained.

The melting point of the pyran derivative of this example is 250 to 2
It is 51 ° C. and has a wavelength of 52 when measured in methylene chloride.
The absorption maximum and the fluorescence maximum were shown at 2 nm and 640 nm, respectively.

[0047]

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In the reference example, the fluorescence maximum was measured by dissolving methylene chloride at a concentration of 10 ^-7 M. Further, the pyran derivative used in the present invention may be slightly different in raw materials, reaction conditions and yield depending on the structure, but may be prepared according to the methods described in Reference Examples, including those represented by Chemical Formula 12, or Can be easily prepared according to the method described in

[0049]

[Example] <Organic EL device> A glass substrate having a transparent ITO electrode having a thickness of 100 nm patterned with water vapor was subjected to ultrasonic cleaning using a neutral detergent, pure water and isopropyl alcohol, and pulled up from boiled isopropyl alcohol. , Dried, washed with ultraviolet ozone, fixed in a vapor deposition apparatus, and then reduced in pressure to 10 ^-7 Torr. Then
With respect to the surface of the glass substrate having the ITO electrode as an anode, N, N'-bis (3-methylphenyl) -N,
N'-diphenyl- [1,1'-biphenyl] -4,4
'-Diamine was deposited to a thickness of 50 nm to form a hole injection / transport layer. Thereafter, while monitoring with a film thickness sensor, tris (8-quinolinolate) aluminum as a host compound (hereinafter abbreviated as “Alq3”)
Then, a pyran derivative represented by Chemical Formula 12 obtained by the method of Reference Example was co-evaporated to a thickness of 15 nm to 1.5 mol% with respect to Alq3 to form a light-emitting layer. The oxadiazole derivative represented by and Alq3 were sequentially deposited to a thickness of 20 nm and 25 nm to form an electron injecting / transporting layer, and then magnesium and silver were co-deposited to a thickness of 200 nm to form a cathode. Thereafter, the entire device was sealed with a glass plate and an ultraviolet curable resin under a nitrogen atmosphere to obtain an organic EL device.

[0050]

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As a control, two kinds of organic EL devices were prepared in the same manner as described above except that the compounding ratio of the pyran derivative to Alq3 was changed to 0.1 mol% and 10 mol%. Was prepared. The luminescence characteristics of the organic EL device thus obtained were tested according to a conventional method. FIG. 2 shows an electroluminescence spectrum of an organic EL device containing 1.5 mol% of a pyrane derivative represented by Chemical Formula 12 as a guest compound.

The organic EL device of this example containing the pyran derivative represented by the formula (12) in an amount of 1.5 mol% has a high potential in the anode with respect to the cathode. , A red light having an emission maximum near a wavelength of 650 nm. When a direct current was applied, light emission was confirmed from around 4 V, and reached the maximum luminance around 13 V. Light emission stably continued, and no partial dark spot (dark spot) was observed even after 100 hours from the start of light emission. Further, as can be seen from the electroluminescence spectrum of FIG. 2, an organic EL using a 1.5 mol% pyran derivative is used.
In the device, no light emission at a wavelength of 550 nm or less due to Alq3 was observed at all.

On the other hand, the control organic EL element using 0.1 mol% of the pyran derivative represented by the chemical formula 12 has significantly lower luminance, does not suppress the emission of Alq3, and is visually observed. The luminescence was close to orange. The control organic EL element using the pyran derivative at 10 mol% was Al
Although the light emission of q3 was not observed, the luminance was 50%.
It had dropped below.

[0054]

As described above, the present invention is based on the discovery of a novel pyran derivative and the discovery of its industrially useful properties. The organic EL device of the present invention comprising the light emitting layer containing the pyran derivative and a quinolinol metal complex,
Since the emission of light having a wavelength of 550 nm or less due to the quinolinol metal complex is not substantially involved, the color purity of emission in the red region is good. Further, since the organic EL device of the present invention is excellent in luminous efficiency and durability, it can be extremely advantageously used in a luminous body as a light source in general lighting and in a wide variety of information display devices for visually displaying information. Can be.

The present invention having such remarkable functions and effects can be said to be a significant invention that greatly contributes to the art.

[Brief description of the drawings]

FIG. 1 is a schematic view of an organic EL device according to the present invention.

FIG. 2 is an electroluminescence spectrum of the organic EL device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection / transport layer 4 Light emitting layer 5 Electron injection / transport layer 6 Cathode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (reference) // C07D 407/06 C07D 407/06 F term (reference) 3K007 AB00 AB03 AB04 CA01 CA02 CA05 CB01 DA00 DB03 EB00 FA01 4C063 AA01 BB04 CC79 DD78 EE10

Claims (7)

[Claims] 1. An organic electroluminescent device using a quinolinol metal complex as a host compound in a light emitting layer,
As the guest compound, the pyran derivative represented by the formula (1) exceeds 0.1 mol% based on the quinolinol metal complex, and
An organic electroluminescent device that emits light in the red region when the amount is less than 0 mol%. Embedded image In Chemical Formula 1, R ₁ and R ₂ each independently represent a hydrogen atom, an alkenyl group, an aryl group or a linear or branched alkyl group, and the aryl group and the alkyl group each have a substituent. You may. R ₃ represents a hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a monovalent group derived from a carboxyl group, or a linear or branched alkyl group, and the alkyl group may have a substituent. Note that R ₁ and / or R ₂ include a nitrogen atom to which they are bonded, or form a cyclic structure including the nitrogen atom and a benzene ring to which the nitrogen atom is bonded. Is also good. 2. A quinolinol metal complex having 8-quinolinols as a ligand and a central atom selected from aluminum, zinc, beryllium, magnesium, indium, lithium, gallium and calcium, or oxidation of these metals. The organic electroluminescent device according to claim 1, wherein the device is an object. 3. A structure in which a hole injection / transport layer and / or an electron injection / transport layer are provided, if necessary, together with an anode, a light-emitting layer and a cathode, and the light-emitting layer is provided with a quinolinol metal complex. 3. The organic electroluminescent device according to claim 1, wherein a pyran derivative is added in an amount of more than 0.1 mol% and less than 10 mol% based on the quinolinol metal complex. 4. The organic electroluminescent device according to claim 1, wherein the emission maximum of emission in the red region is in the range of wavelengths from 600 to 670 nm. 5. The organic electroluminescent device according to claim 1, wherein the quinolinol metal complex does not substantially emit light. 6. An information display device using the organic electroluminescent device according to claim 1. 7. A luminous body using the organic electroluminescent device according to claim 1.