JPH11111458A - Organic electroluminescent element material and organic electroluminescent element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element having high luminous brightness and luminous efficiency and good stability to repeated use by using a specified luminescent material for the organic electroluminescent(EL) element. SOLUTION: This luminescent material for an organic electroluminescent(EL) element is defined by the formula. In the formula, A<1> -A<2> independently an optionally substituted alkyl group, alkoxy group, aryloxy group, condensed polycyclic group, alkylamino group, and arylamino group. R<1> -R<16> are independently hydrogen, a halogen, cyano group, nitro group, an optionally substituted alkyl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, cyclic group, and amino group. A compound where neighboring substituents of R<1> -R<16> form an aromatic ring, has high glass transition temperature and melting point and the heat resistance is improved, so when such a compound is used as a luminescent material for an organic electroluminescent element, high luminous brightness is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting material for an organic electroluminescence (EL) device used for a flat light source or display and a light emitting device having a high luminance.

[0002]

2. Description of the Related Art An EL device using an organic substance is expected to be used as an inexpensive, large-area, full-color display device of a solid light emitting type, and many developments have been made. Generally EL
Is composed of a light-emitting layer and a pair of opposed electrodes sandwiching the layer. In light emission, when an electric field is applied between both electrodes, electrons are injected from the cathode side and holes are injected from the anode side. Further, the electrons are recombined with holes in the light emitting layer, and energy is emitted as light when the energy level returns from the conduction band to the valence band.

[0003] Conventional organic EL devices have a higher driving voltage and lower luminous brightness and luminous efficiency than inorganic EL devices.
In addition, the characteristic deterioration was remarkable, and it had not been put to practical use.
2. Description of the Related Art In recent years, an organic EL in which thin films containing an organic compound having high fluorescence quantum efficiency and emitting light at a low voltage of 10 V or less are laminated.
Devices have been reported and are of interest (see Applied Physics Letters, vol. 51, p. 913, 1987). This method uses a metal chelate complex for a light emitting layer and an amine compound for a hole injection layer to obtain high-intensity green light emission.
d / m ² and maximum luminous efficiency of 1.5 lm / W,
Has performance close to the practical range.

[0004] However, organic EL devices up to now have improved luminous intensity due to the improved structure, but do not yet have sufficient luminous brightness. In addition, there is a major problem that the stability upon repeated use is poor. This is because, for example, a metal chelate complex such as a tris (8-hydroxyquinolinato) aluminum complex is chemically unstable during electroluminescence, has poor adhesion to a cathode, and is greatly deteriorated by short-time light emission. I was For the above reasons, in order to develop an organic EL device having high luminous luminance and luminous efficiency and excellent stability in repeated use, development of a durable luminescent material having excellent luminous ability has been required. Is desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic EL device having a high emission luminance and excellent stability when used repeatedly. As a result of intensive studies by the present inventors, the organic EL device using the light emitting material for an organic EL device represented by the general formulas [1] to [5] in the light emitting layer has high light emission luminance and light emission efficiency and is repeatedly used. It has been found that the stability at the time is excellent, and the present invention has been achieved.

[0006]

The present invention relates to a luminescent material for an organic electroluminescence device represented by the following general formula [1]. General formula [1]

Embedded image [Wherein A ^{1 and} A ² each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted fused polycyclic group, Represents a substituted or unsubstituted alkylamino group or a substituted or unsubstituted arylamino group. R ^{1 to} R ¹⁶ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, Represents an unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (even if adjacent groups are bonded to each other to form a new ring, Good.) ]

Further, the present invention relates to a light emitting material for an organic electroluminescence device represented by the following general formula [2]. General formula [2]

[0008]

Embedded image

Wherein A ^{3 to} A ⁶ are each independently:
Represents a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. R ^{1 to} R ¹⁶ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, Represents an unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (even if adjacent groups are bonded to each other to form a new ring, Good.) ]

Further, the present invention relates to a luminescent material for an organic electroluminescent device represented by the following general formula [3]. General formula [3]

[0011]

Embedded image

[Wherein, R ^{1 to} R ³⁶ each independently represent
Hydrogen atom, halogen atom, cyano group, nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted Represents an arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (R ^{1 to} R ¹⁶ may be mutually bonded by adjacent groups to form a new ring). ]

Further, the present invention relates to a luminescent material for an organic electroluminescence device represented by the following general formula [4]. General formula [4]

[0014]

Embedded image

Wherein R ^{1 to} R ¹⁶ and R ^{37 to} R ⁵⁶ are
Each independently represents a hydrogen atom, a halogen atom, a cyano group,
Nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group,
Represents a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (R
^{1 to} R ¹⁶ may be mutually bonded by adjacent groups to form a new ring. ). X ^{1 to} X ⁴ are each independently O, S, C ＝ O, SO ₂ , (CH ₂ ) x-O
- (CH ₂₎ y, a substituted or unsubstituted alkylene group,
Represents a substituted or unsubstituted aliphatic ring group. Here, x and y represent positive integers of 0 to 20, but x + y = 0 does not occur. ]

Further, the present invention relates to a light emitting material for an organic electroluminescence device represented by the following general formula [5]. General formula [5]

[0017]

Embedded image

Wherein R ^{1 to} R ¹⁶ and R ^{37 to} R ⁵⁶ are
Each independently represents a hydrogen atom, a halogen atom, a cyano group,
Nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group,
Represents a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (R
^{1 to} R ¹⁶ may be mutually bonded by adjacent groups to form a new ring. ). Y ^{1 to} Y ⁸ represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms and a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. Further, Y ¹ and Y ^2, Y ³ and Y ^4, Y ⁵ and Y ^6, Y ⁷ and Y ⁸
May form a substituted or unsubstituted aliphatic cyclic group having 5 to 7 carbon atoms. ]

Further, the present invention relates to an organic electroluminescence device in which a plurality of organic compound thin films including a light emitting layer are formed between a pair of electrodes, wherein at least one layer is a layer containing the organic electroluminescence device material. Related to the element.

Further, the present invention relates to an organic electroluminescence device in which a plurality of organic compound thin films including a light emitting layer are formed between a pair of electrodes, wherein the light emitting layer is a layer containing the organic electroluminescent device material. Related to the element.

Further, the present invention relates to an organic electroluminescence device in which a plurality of organic compound thin films including a light emitting layer are formed between a pair of electrodes, wherein the light emitting layer comprises a host material and a doping material, and the doping material is the organic electroluminescent device. The present invention relates to an organic electroluminescent device that is a luminescent device material.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, A ^{1 to} A ² of the compound represented by the general formula [1] each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkoxy group. Represents a substituted aryloxy group, a substituted or unsubstituted fused polycyclic group, a substituted or unsubstituted alkylamino group, or a substituted or unsubstituted arylamino group. Examples of the alkyl group include a linear or branched alkyl group having 1 to 20 carbon atoms, and a cycloalkyl group.
Specific examples of the linear or branched alkyl group include methyl, ethyl, propyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, and stearyl. , A trichloromethyl group, and specific examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group.

The alkoxy group includes a linear or branched alkoxyl group having 1 to 20 carbon atoms, and specific examples thereof include a methoxy group, an ethoxy group, an n-butoxy group, and a tertiary alkoxy group.
t-butoxy group, trichloromethoxy group, trifluoroethoxy group, pentafluoropropoxy group, 2,2
3,3-tetrafluoropropoxy group, 1,1,1,
3,3,3-hexafluoro-2-propoxy group, 6-
And a (perfluoroethyl) hexyloxy group. Specific examples of the aryloxy group include a phenoxy group and p-
Examples include a nitrophenoxy group, a p-tert-butylphenoxy group, a 3-fluorophenoxy group, a pentafluorophenyl group, and a 3-trifluoromethylphenoxy group.

Examples of the condensed polycyclic group include naphthyl, anthryl, phenanthryl, fluorenyl, pyrenyl, indole, purine, quinoline, isoquinoline, sinoline, quinoxaline, benzoquinoline, fluorenone, Carbazole group, oxazole group, oxadiazole group, thiazole group, thiadiazole group, triazole group, imidazole group, benzoxazole group, benzothiazole group, benzotriazole group, benzimidazole group, bisbenzoxazole group, bisbenzothiazole group, bis Examples include a benzimidazole group, an anthrone group, a dibenzofuran group, a dibenzothiophene group, an anthraquinone group, an acridone group, a phenothiazine group, a pyrrolidine group, a dioxane group, and a morpholine group.

Specific examples of the alkylamino group include an ethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, a benzylamino group and a dibenzylamino group. Specific examples of the arylamino group include a phenylamino group, a (3-methylphenyl) amino group, and a (4-methylphenyl) amino group.
Methylphenyl) amino group, phenylmethylamino group,
Diphenylamino group, ditolylamino group, dibiphenylamino group, di (4-methylbiphenyl) amino group, di (3-methylphenyl) amino group, di (4-methylphenyl) amino group, naphthylphenylamino group, bis [4
-(Α, α'-dimethylbenzyl) phenyl] amino group and the like.

A ^{3 to} A ⁶ in the general formula [2] represent a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group,
An aryl group having 6 to 16 carbon atoms, such as an anthryl group, a phenanthryl group, a fluorenyl group, a pyrenyl group, and the like, and each aryl group may have a substituent. The aromatic carbon atom of the aryl group may be substituted by a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of such an aryl group containing a hetero atom include a furanyl group, a thiophenyl group, a pyronyl group, and a pyridine group. Further, A ³ and A ⁴ or A ⁵ and A ⁶ may be combined to form an aryl group containing a nitrogen atom such as a carbazole group.

In the present invention, the substituents R ^{1 to} R ⁵⁶ of the compounds represented by the general formulas [1] to [5] are each independently
Hydrogen atom, halogen atom, cyano group, nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted Represents an arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group. Adjacent groups R ^{1 to} R ¹⁶ may be bonded to each other to form a saturated or unsaturated ring such as a phenyl ring, a naphthyl ring, an anthryl ring, a pyrenyl ring, a carbazole ring, a benzopyranyl ring, a cyclohexyl ring. Good.

The substituents of A ^{1 to} A ⁶ and R ¹ to
Specific examples of R ⁵⁶ are, as examples of the fluorine, chlorine, bromine, iodine, substituted or unsubstituted alkyl group halogen atom, methyl group, ethyl group, propyl group, butyl group, se
c-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, unsubstituted alkyl group having 1 to 20 carbon atoms such as stearyl group, 2-phenylisopropyl group, trichloromethyl group, Trifluoromethyl group, benzyl group, α-phenoxybenzyl group, α,
Substitution of C1-C20 alkyl groups such as α'-dimethylbenzyl group, α, α'-methylphenylbenzyl group, α, α-ditrifluoromethylbenzyl group, triphenylmethyl group, α-benzyloxybenzyl group, etc. Have a body,
Examples of the substituted or unsubstituted alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, a t-
Butoxy group, n-octyloxy group, unsubstituted alkoxy group having 1 to 20 carbon atoms such as t-octyloxy group,
There are substituted alkoxy groups having 1 to 20 carbon atoms such as 1,1,1-tetrafluoroethoxy group, phenoxy group, benzyloxy group and octylphenoxy group.

The ring group includes a monocyclic group and a condensed polycyclic group. The monocyclic group includes a monocyclic cycloalkyl group, a monocyclic aryl group, a monocyclic heterocyclic group, and the like. Examples of the monocyclic cycloalkyl group include a cycloalkyl group having 4 to 8 carbon atoms such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

The monocyclic aryl group includes a phenyl group. As a monocyclic heterocyclic group, a thionyl group, a thiophenyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a pyrazolyl group, a pyridyl group, a pyrazinyl group, a pyrimidinyl group,
Examples include a pyridazinyl group, an oxazolyl group, a thiazolyl group, an oxadiazolyl group, a thiadiazolyl group, and an imidadiazolyl group.

Examples of the condensed polycyclic group include a condensed polycyclic aryl group, a condensed polycyclic heterocyclic group and a condensed polycyclic cycloalkyl group. Examples of the condensed polycyclic aryl group include a naphthyl group, an anthranyl group, a phenanthrenyl group, a fluorenyl group, an acenaphthyl group, an azulenyl group, a heptalenyl group, an acenaphthylenyl group, a pyrenyl group and the like.

Examples of the condensed polycyclic heterocyclic group include indolyl, quinolyl, isoquinolyl, phthalazinyl, quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenazinyl, furfuryl, isothiazolyl, isoxazolyl, and furazanyl. Phenoxazinyl group, benzothiazolyl group, benzoxazolyl group, benzimidazolyl group and the like. Other fused polycyclic groups include a 1-tetralyl group, a 2-tetralyl group, a tetrahydroquinolyl group, and the like.

The substituted or unsubstituted amino group includes an amino group, a dimethylamino group, a diethylamino group, a phenylmethylamino group, a diphenylamino group, a ditolylamino group, a dibenzylamino group and the like.

In the present invention, X1 to X4 of the compounds represented by the general formulas [3] and [4] each independently represent O, S, C ＝ O, SO ₂ , (CH ₂ ) _x -O- (C
H ₂ ) _{y represents} a substituted or unsubstituted alkylene group or a substituted or unsubstituted aliphatic residue.

As the substituted or unsubstituted alkylene group, an alkylene group having 1 to 20 carbon atoms or a substituted product thereof, and as the substituted or unsubstituted aliphatic residue, a cyclopentyl group, a cyclohexyl group, a 4-methylcyclohexyl group, An aliphatic divalent residue having 5 to 7 carbon atoms such as a cycloheptyl group is exemplified. The substituted alkylene group for X ^{1 to} X ⁴ or the substituent for the substituted aliphatic ring residue includes R ^{1 to} R 4
There are substituents shown at ⁵⁶ .

Preferred as the substituted alkylene group for X ^{1 to} X ⁴ are 2-phenylisopropylene group, dichloromethylene group, difluoromethylene group, benzylene group, α
-Phenoxybenzylene group, α, α′-dimethylbenzylene group, α, α′-methylphenylbenzylene group, diphenylmethylene group, α-benzyloxybenzylene group and the like.

In the present invention, Y ¹ to Y ⁸ of the compound represented by the general formula [5] represent a substituted or unsubstituted C ¹ -C 1.
20 alkyl groups, substituted or unsubstituted 6-1 carbon atoms
6 represents an aryl group. Further, in Y ¹ and Y ^2, Y ³ and Y ^4, Y ⁵ and Y ^6, Y ⁷ and Y ^8, may form an aliphatic ring group having 5 to 7 carbon atoms substituted or unsubstituted. Specific examples of the alkyl group and the aromatic ring group include the alkyl groups and the aryl groups described for R ^{1 to} R ⁵⁶ above.

Among these compounds, general formulas [3] to [5]
Or a compound having a substituent having an aromatic ring represented by the general formulas [1] to [5], wherein adjacent substituents of R ^{1 to} R ⁵⁶ form an aromatic ring. Compounds are
Since the glass transition point and melting point increase, the resistance (heat resistance) to Joule heat generated in the organic layer, between the organic layers, or between the organic layer and the metal electrode during electroluminescence improves.
When used as a light-emitting material for an organic EL element, it exhibits high light emission luminance and is advantageous for long-term light emission. The compounds of the present invention are not limited to these substituents.

In the present invention, the compounds represented by the general formulas [1] to [5] can be synthesized, for example, by the following method. The compound of the following general formula [6] is reacted with butyllithium in diethyl ether, and this is cross-coupled in the presence of cobalt chloride and n-butylbromide, or is reacted with nickel in N, N-dimethylformamide. The compound of the general formula [6] is cross-coupled with a catalyst, or the compound of the general formula [7] is Grignarded with metallic magnesium in tetrahydrofuran, and the compound of the general formula [6] is cross-coupled with the compound of general formula [6]. It can be obtained by ringing. Hereinafter, typical examples of the compound of the present invention are specifically illustrated in Table 1, but the present invention is not limited to the following typical examples.

General formula [6]

Embedded image

General formula [7]

Embedded image [Wherein, A ^{1 to} A ² and R ^{1 to} R ¹⁶ are the same as described above. ]

[0042]

[Table 1]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

The organic EL device is a device in which one or more organic thin films are formed between an anode and a cathode. In the case of a single layer type, a light emitting layer is provided between an anode and a cathode. The light-emitting layer contains a light-emitting material and may further contain a hole-injection material or an electron-injection material for transporting holes injected from an anode or electrons injected from a cathode to the light-emitting material. The multilayer type is (anode / hole injection layer / light emitting layer /
There is an organic EL device having a multilayer structure of (cathode), (anode / light-emitting layer / electron injection layer / cathode), and (anode / hole injection layer / light-emitting layer / electron injection layer / cathode). General formula [1] of the present invention
Since the compounds represented by [5] are compounds having strong fluorescence in a solid state and excellent in electroluminescence, they can be used in a light emitting layer as a light emitting material. Also,
By doping the compounds of the general formulas [1] to [5] as a doping material in the light emitting layer at an optimum ratio in the light emitting layer, it is possible to select a high light emitting efficiency and an optimum light emitting wavelength. Further, the compounds represented by the general formulas [1] to [5] can transport carriers such as holes or electrons, and thus can be used for a hole injection layer or an electron injection layer of an organic EL device. .

By using the compounds of the general formulas [1] to [5] as the doping material (guest material) as the host material of the light emitting layer, an organic EL device having high emission luminance can be obtained. The compounds of the general formulas [1] to [5] are desirably contained in the light-emitting layer in a range of 0.001% by weight to 50% by weight relative to the host material, and more preferably 0.1% by weight.
The range from 01% by weight to 10% by weight is effective.

Examples of the host material usable in combination with the compounds of the general formulas [1] to [5] include quinoline metal complex, oxadiazole, benzothiazole metal complex, benzoxazole metal complex, benzimidazole metal complex, triazole, imidazole , Oxazole, oxadiazole, stilbene, butadiene, benzidine triphenylamine, styrylamine triphenylamine, diamine triphenylamine fluorenone, diaminoanthracene triphenylamine, diaminophenanthrene triphenylamine, anthraquinodimethane, Diphenoquinone, thiadiazole, tetrazole, perylenetetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, triphenylene, anthrone and their derivatives, and , Polyvinylcarbazole, there polymeric materials and the like of the conductive polymer and polysilane, and the like.

It is also possible to change the emission color by using a further doping material together with the general formulas [1] to [5]. Examples of the doping materials used in combination with the general formulas [1] to [5] include anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein, perylene, phthaloperylene, naphthaloperylene, perinone, phthaloperinone, naphthaloperinone,
Diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, imine, diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran , Polymethine, merocyanine, imidazole chelated oxinoid compounds, quinacridone, rubrene and the like, and their derivatives, but are not limited thereto.

For the light emitting layer, a hole injection material or an electron injection material can be used if necessary, in addition to the light emitting material and the doping material.

When the organic EL element has a multilayer structure, it is possible to prevent a decrease in luminance and life due to quenching. If necessary, a combination of two or more kinds of light emitting materials, doping materials, hole injecting materials for injecting carriers, and electron injecting materials can also be used. Also,
The hole injection layer, the light-emitting layer, and the electron injection layer may each be formed in a layer structure of two or more layers, and an element structure in which holes or electrons are efficiently injected from the electrode and transported in the layer is selected. You.

The conductive material used for the anode of the organic EL device preferably has a work function larger than 4 eV, and is preferably selected from carbon, aluminum, vanadium, iron, cobalt, and the like.
Nickel, tungsten, silver, gold, platinum, palladium and the like and alloys thereof, ITO substrate, metal oxide such as tin oxide and indium oxide called NESA substrate, and organic conductive resin such as polythiophene and polypyrrole are used. . The conductive material used for the cathode is preferably one having a work function of less than 4 eV, such as magnesium, calcium, tin, lead, titanium, yttrium,
Lithium, ruthenium, manganese and the like and alloys thereof are used. Representative examples of the alloy include magnesium / silver, magnesium / indium, and lithium / aluminum, but are not limited thereto. The ratio of the alloy is controlled by the heating temperature, atmosphere, and degree of vacuum, and an appropriate ratio is selected. The anode and the cathode may be formed by two or more layers if necessary.

In the organic EL device, it is desirable that at least one of the organic EL devices is sufficiently transparent in the emission wavelength region of the device in order to emit light efficiently. Further, it is desirable that the substrate is also transparent. The transparent electrode is set so as to secure a predetermined translucency by a method such as vapor deposition or sputtering using the above conductive material. The electrode on the light emitting surface desirably has a light transmittance of 10% or more. The substrate is not limited as long as it has mechanical and thermal strength and is transparent, but examples thereof include a transparent resin such as a glass substrate, a polyethylene plate, a polyether sulfone plate, and a polypropylene plate. .

Each layer of the organic EL element according to the present invention can be formed by any of dry film forming methods such as vacuum evaporation and sputtering and wet film forming methods such as spin coating and dipping. The thickness is not particularly limited, but each layer needs to be set to an appropriate thickness. If the film thickness is too large, a large applied voltage is required to obtain a constant light output, resulting in poor efficiency. If the film thickness is too small, pinholes and the like are generated, and sufficient light emission luminance cannot be obtained even when an electric field is applied. Normal thickness is 5nm to 10μ
The range of m is suitable, but the range of 10 nm to 0.2 μm is more preferable.

In the case of the wet film forming method, a material for forming each layer is dissolved or dispersed in a suitable solvent such as chloroform, tetrahydrofuran, dioxane or the like to form a thin film.
The solvent may be any. In any of the thin films, a suitable resin or additive may be used to improve film forming properties, prevent pinholes in the film, and the like. Examples of such a resin include insulating resins such as polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyurethane, polysulfone, polymethyl methacrylate, polymethyl acrylate, and cellulose, and poly-N-.
Examples include photoconductive resins such as vinyl carbazole and polysilane, and conductive resins such as polythiophene and polypyrrole. Examples of the additive include an antioxidant, an ultraviolet absorber, and a plasticizer.

The hole injecting material has the ability to inject holes, has an excellent hole injecting effect on the light emitting layer or the light emitting material, and has an electron injecting layer or an electron of excitons generated in the light emitting layer. Compounds that prevent migration to the injection material and have excellent thin film forming ability are mentioned. Specifically, phthalocyanine compounds, naphthalocyanine compounds, porphyrin compounds, oxadiazole, triazole, imidazole, imidazolone, imidazolethione, pyrazoline, pyrazolone, tetrahydroimidazole, oxazole, oxadiazole, hydrazone, acylhydrazone, poly Arylalkane, stilbene, butadiene,
Benzidine-type triphenylamine, styrylamine-type triphenylamine, diamine-type triphenylamine and the like, and derivatives thereof, and polyvinyl carbazole,
Although there are polymer materials such as polysilane and conductive polymer,
It is not limited to these.

Among the hole injection materials that can be used in the organic EL device of the present invention, more effective hole injection materials are
It is an aromatic tertiary amine derivative or a phthalocyanine derivative. Specifically, triphenylamine, tolylamine, tolylphenylamine, N, N′-diphenyl-N, N ′-(3-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N, N ', N'-
(4-methylphenyl) -1,1′-phenyl-4,
4'-diamine, N, N, N ', N'-(4-methylphenyl) -1,1'-biphenyl-4,4'-diamine, N, N'-diphenyl-N, N'-dinaphthyl-
1,1′-biphenyl-4,4′-diamine, N, N ′
-(Methylphenyl) -N, N '-(4-n-butylphenyl) -phenanthrene-9,10-diamine, N,
N-bis (4-di-4-tolylaminophenyl) -4-
Examples include, but are not limited to, phenyl-cyclohexane and the like, and oligomers and polymers having an aromatic tertiary amine skeleton. As phthalocyanine (Pc) derivatives, H ₂ Pc, CuPc,
CoPc, NiPc, ZnPc, PdPc, FePc,
MnPc, ClAlPc, ClGaPc, ClInP
c, ClSnPc, Cl ₂ SiPc, (HO) AlP
c, (HO) GaPc, VOPc, TiOPc, MoO
Examples include, but are not limited to, phthalocyanine derivatives such as Pc, GaPc-O-GaPc and naphthalocyanine derivatives.

The electron injecting material has a capability of injecting electrons, has an excellent electron injecting effect on the light emitting layer or the light emitting material, and has a hole injecting layer or hole injection of excitons generated in the light emitting layer. Compounds that prevent transfer to a material and have excellent thin film forming ability are exemplified. For example, quinoline metal complex, oxadiazole, benzothiazole metal complex, benzoxazole metal complex, benzimidazole metal complex, fluorenone, anthraquinodimethane, diphenoquinone, thiopyrandioxide, oxadiazole, thiadiazole, tetrazole, perylenetetracarbon Acid, fluorenylidenemethane, anthraquinodimethane,
Examples include, but are not limited to, anthrones and derivatives thereof. Alternatively, an electron accepting substance may be added to the hole injecting material, and an electron donating substance may be added to the electron injecting material for sensitization.

In the organic EL device of the present invention, a more effective electron injecting material is a metal complex compound or a nitrogen-containing five-membered ring derivative. Specifically, as the metal complex compound, lithium 8-hydroxyquinolinate, bis (8
-Hydroxyquinolinato) zinc, bis (8-hydroxyquinolinato) copper, bis (8-hydroxyquinolinato) manganese, tris (8-hydroxyquinolinato)
Aluminum, tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (8-hydroxyquinolinato) gallium, bis (10-hydroxybenzo [h] quinolinato) beryllium, bis (10-hydroxybenzo [h] (Quinolinato) zinc, bis (2-methyl-8-quinolinato) chlorogallium, bis (2-methyl-8-quinolinato) (o-cresolate) gallium, bis (2-methyl-8-quinolinato) (1-naphtholate) aluminum , Bis (2-methyl-8-quinolinato) (2-naphtholate) gallium and the like,
It is not limited to these. As the nitrogen-containing five-membered derivative, an oxazole, thiazole, oxadiazole, thiadiazole or triazole derivative is preferable. Specifically, 2,5-bis (1-phenyl)
-1,3,4-oxazole, dimethyl POPOP,
2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1-phenyl) -1,3,4-oxadiazole, 2- (4′-tert-butylphenyl) ) -5- (4 "-biphenyl) 1,3,4-oxadiazole, 2,5-bis (1-naphthyl) -1,3,4
-Oxadiazole, 1,4-bis [2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2-
(5-phenyloxadiazolyl) -4-tert-butylbenzene], 2- (4'-tert-butylphenyl) -5- (4 "-biphenyl) -1,3,4-thiadiazole, 2,5- Bis (1-naphthyl) -1,3,4
-Thiadiazole, 1,4-bis [2- (5-phenylthiadiazolyl)] benzene, 2- (4'-tert-
(Butylphenyl) -5- (4 "-biphenyl) -1,
3,4-triazole, 2,5-bis (1-naphthyl)
-1,3,4-triazole, 1,4-bis [2- (5
-Phenyltriazolyl)] benzene and the like, but are not limited thereto.

In the present organic EL device, the light emitting layer contains
In addition to the compounds of the general formulas [1] to [5], at least one of a light emitting material, a doping material, a hole injection material and an electron injection material may be contained in the same layer. In order to improve the stability of the organic EL device obtained according to the present invention with respect to temperature, humidity, atmosphere, and the like, a protective layer may be provided on the surface of the device, or the entire device may be protected with silicon oil, resin, or the like. Is also possible.

As described above, by using the compound of the present invention in the light emitting layer of the organic EL device and further combining the compound with a specific hole injection layer or electron injection layer, the organic EL device having the luminous efficiency and the maximum luminous luminance can be obtained. The properties could be improved. In addition, this device is extremely stable against heat and current, and furthermore, it can emit light that can be practically used at a low driving voltage, so that the deterioration, which has been a major problem until now, can be significantly reduced. Was completed.

The organic EL device of the present invention can be used as a flat panel display such as a wall-mounted television or a flat luminous body.
It can be applied to light sources such as copiers and printers, light sources such as liquid crystal displays and instruments, display boards, and sign lamps, and its industrial value is extremely large.

The material of the present invention can be used in the fields of organic EL devices, electrophotographic photosensitive members, photoelectric conversion devices, solar cells, image sensors and the like.

[0068]

The present invention will be described in more detail with reference to the following examples. Method for synthesizing compound (16) 300 ml of diethyl ether was placed in a flask, and 9- (di-p-tolylamino) -10-bromo- was added under a nitrogen stream.
4.52 g of anthracene were dissolved. To this, 6.9 ml of n-butyllithium (1.6 M hexane solution) was slowly added to produce a white lithium compound. Further, 0.05 g of cobalt chloride and 2 ml of n-butyl bromide were added, and the mixture was stirred for 24 hours at room temperature. After the reaction,
Water was added and the resulting precipitate was collected by filtration. The precipitate was subjected to column purification using silica gel to obtain 1.8 g of a yellow powder. This was purified by sublimation. The formation of the compound was confirmed by NMR, FD-MS, and IR. IR of compound (16)
The spectrum diagram is shown in FIG.

Synthesis method of compound (24) 20 ml of N, N-dimethylformamide was placed in a flask, and 10 g of 9- (di-p-methoxyphenylamino) -10-bromo-anthracene and bis (1,
0.37 g of 5-cyclooctadiene) nickel, 2,
0.2 g of 2′-bipyridine and 0.2 ml of 1,5-cyclooctadiene were added, and the mixture was heated and stirred at 60 ° C. for 24 hours. After completion of the reaction, water was added and the resulting precipitate was collected by filtration. The precipitate was subjected to column purification using silica gel, followed by sublimation purification to obtain 3.5 g of a blue solid. NMR, FD-
The production of the compound was confirmed by MS and IR spectra.

Method for synthesizing compound (30) Under an argon stream, THF (20 ml), 9- (di-p-phenoxyphenylamino) -10-bromo-anthracene (4 g), magnesium for Grignard reaction (0.26 g)
Was placed in a flask, a piece of iodine was added, and the mixture was Grignarded. The reaction solution became white milky liquid, and after confirming that magnesium had reacted, 0.4 g of bis (triphenylphosphine) nickel (II) chloride was added to the reaction solution, and 9-bromodiamine was dissolved in 50 ml of THF. −
5 g of 10- (di-p-biphenylaminophenyl) anthracene was added, and the mixture was heated and stirred at 60 ° C. for 10 hours. After completion of the reaction, 3% aqueous hydrochloric acid was added, and the resulting precipitate was collected by filtration. The precipitate was subjected to column purification on silica gel.
2.5 g of the obtained pale yellow solid was purified by sublimation.
8 g of compound (30) was obtained. NMR, FD-MS, I
The formation of the compound was confirmed by the R spectrum.

Example 1 A compound (15) shown in Table 1 and 2,5-bis (1-naphthyl) as a luminescent material were placed on a washed glass plate with an ITO electrode.
-1,3,4-oxadiazole, polycarbonate resin (Teijin Chemical: Panlite K-1300) in 5: 3: 2
Was dissolved in tetrahydrofuran at a weight ratio of, and a light-emitting layer having a thickness of 100 nm was obtained by spin coating. An electrode having a thickness of 150 nm was formed thereon using an alloy in which magnesium and silver were mixed at a ratio of 10: 1 to obtain an organic EL device. The light emission characteristics of this element are 120 (cd / m) at a DC voltage of 5 V.
² ), maximum brightness 1100 (cd / m ²⁾ , luminous efficiency 0.7
Green light emission of 0 (lm / W) was obtained.

Example 2 N, N ′-(3
-Methylphenyl) -N, N'-diphenyl-1,1-
Biphenyl-4,4-diamine (TPD) was vacuum-deposited to obtain a hole injection layer having a thickness of 20 nm. Next, a compound (16) was deposited to form a light emitting layer having a thickness of 40 nm, and a tris (8-hydroxyquinoline) aluminum complex (Al
q3) was deposited to obtain an electron injection layer having a thickness of 30 nm. An electrode having a thickness of 100 nm was formed thereon using an alloy in which magnesium and silver were mixed at a ratio of 10: 1 to obtain an organic EL device.
The hole injection layer and the light emitting layer are formed in a vacuum of 10 ^-6 Torr,
The deposition was performed at a substrate temperature of room temperature. This device has a light emission luminance of 100 (cd / m ² ) at a DC voltage of 5 V and a maximum light emission luminance of 1
5000 (cd / m ² ), luminous efficiency at 5 V of 1.5
A blue-green emission of (lm / W) was obtained.

Example 3 Compound (25) was placed on a washed glass plate with an ITO electrode.
Was dissolved in methylene chloride, and a hole injection type light emitting layer having a thickness of 50 nm was obtained by a spin coating method. Then, a bis (2-methyl-8-quinolinato) (1-naphtholate) gallium complex was vacuum-deposited to form an electron injection layer having a thickness of 10 nm, and magnesium and silver were added thereto in a ratio of 10: 1.
An electrode having a thickness of 100 nm was formed from the alloy mixed in the above step to obtain an organic EL device. The light emitting layer and the electron injection layer are 10 ^-6 To
Vapor deposition was performed at a substrate temperature of room temperature in a vacuum of rr. This device has a luminance of 300 (cd / m ² ) at a DC voltage of 5 V, a maximum luminance of 2200 (cd / m ² ), and a luminous efficiency of 0.80 (lm).
/ W) was obtained.

Example 4 Compound (27) was placed on a washed glass plate with an ITO electrode.
Vacuum evaporation was performed to obtain a 50-nm-thick hole injection type light-emitting layer. Then, bis (2-methyl-8-quinolinate)
(1-Naphtholate) gallium complex is vacuum-deposited to form an electron injection layer having a thickness of 10 nm, and an electrode having a thickness of 100 nm is formed on the electron injection layer with an alloy of magnesium and silver mixed at a ratio of 10: 1. An element was obtained. Emitting layer and the electron injection layer 10 ^- of ⁶ Torr in vacuum, and deposited under a substrate temperature of room temperature. This element is 400V at 5V DC.
(Cd / m ² ), maximum brightness 10200 (cd / m ² ),
Blue-green light emission with a luminous efficiency of 1.10 (lm / W) was obtained.

Examples 5 to 40 A compound (39) represented by the following chemical structure was vacuum-deposited on a washed glass plate with an ITO electrode to form a film having a thickness of 20 nm.
To form a hole injection layer. Next, the compounds shown in Table 1 were vacuum-deposited as light-emitting materials to obtain a light-emitting layer having a thickness of 20 nm. Then, bis (2-methyl-8-quinolinate)
(1-Naphtholate) gallium complex is vacuum-deposited to form an electron injection layer having a thickness of 10 nm, and an electrode having a thickness of 100 nm is formed on the electron injection layer with an alloy of magnesium and silver mixed at a ratio of 10: 1. An element was obtained. The hole injection layer and the light emitting layer were deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. Table 2 shows the light emission characteristics of this device. The emission luminance here is the luminance when a DC voltage of 5 V is applied. All of the organic EL elements of this embodiment have a maximum luminance of 10,000 (c
d / m ² ) or more, and a desired emission color could be obtained.

Compound (39)

Embedded image

[0077]

[Table 2]

Example 41 4, 4 ′, 4 ″ was placed on a washed glass plate with an ITO electrode.
-Tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine was vacuum deposited to a film thickness of 40
As a result, a hole injection layer having a thickness of nm was obtained. Then, 4,4′-bis [N
-(1-Naphthyl) -N-phenylamino] biphenyl (α-NPD) was vacuum-deposited to obtain a 10-nm-thick second hole injection layer. Further, the compound (31) was vacuum-deposited to form a light-emitting layer having a thickness of 30 nm.
A methyl-8-hydroxyquinolinato) (1-phenolate) gallium complex was vacuum-deposited to form a 30-nm-thick electron injection layer, on which aluminum and lithium were added for 2 hours.
An electrode having a thickness of 150 nm was formed from an alloy mixed at 5: 1 to obtain an organic EL device. The hole injection layer and the light emitting layer are 1
Vapor deposition was performed at a substrate temperature of room temperature in a vacuum of 0 ^-6 Torr. This device has a light emission luminance of 310 (c) at a DC voltage of 5 V.
d / m ² ), maximum emission luminance 29000 (cd / m ² ),
Blue-green light with a luminous efficiency of 2.8 (lm / W) was obtained.

Example 42 An organic EL device was manufactured in the same manner as in Example 3, except that a hole injection layer having a thickness of 5 nm made of metal-free phthalocyanine was provided between the ITO electrode and the compound (33). This device has a DC voltage of 5 V, 1200 (cd / m ² ), a maximum luminance of 19000 (cd / m ² ), and a luminous efficiency of 1.70 (lm / m ² ).
Blue-green light emission of W) was obtained.

Example 43 4,4 ', 4 "-Tris [N- (3-methylphenyl)
-N-phenylamino] triphenylamine
A 20-nm-thick hole injection layer of metal-free phthalocyanine was provided.
An organic EL device was prepared in the same manner as in Example 41, except that
Produced. This element is 250 (cd /
m^Two), Maximum brightness 15000 (cd / m ^Two), Luminous efficiency
Blue light emission of 1.30 (lm / W) was obtained.

Example 44 As a light emitting layer, compound (36): compound (40)
An organic EL device was manufactured in the same manner as in Example 41, except that a 10-nm thick hole injection layer deposited at a ratio of 0: 1 was provided. This element is 1100 (cd) at a DC voltage of 5 V.
/ M ^2), the maximum luminance 25000 (cd / m ^2), blue green light emission efficiency 2.10 (lm / W) was obtained.

Compound (40)

Embedded image

Example 45 Compound (36): Compound (41) was used as a light emitting layer in 10
An organic EL device was manufactured in the same manner as in Example 41, except that a 10-nm thick hole injection layer deposited at a ratio of 0: 1 was provided. This element is 600 (cd /
m ² ), orange light emission having a maximum luminance of 12000 (cd / m ² ) and a luminous efficiency of 1.10 (lm / W) was obtained.

Compound (41)

Embedded image

The organic EL device shown in this embodiment has a maximum light emission luminance of 10,000
Light emission of (cd / m ² ) or more was obtained, and high luminous efficiency was obtained in all cases. When the organic EL device shown in this example was continuously emitted at 3 (mA / cm ² ), stable emission was observed for 1000 hours or more. The organic EL device of the present invention achieves improvement in luminous efficiency, luminous brightness and long life, and is used together with a luminescent material, a doping material, a hole injection material, an electron injection material, a sensitizer, and a resin. It does not limit the electrode material, etc., and the element manufacturing method.

[0086]

According to the organic EL device using the organic EL device material of the present invention as a light-emitting material, the device emits light with high luminous efficiency and high luminance as compared with the prior art, and a long-life organic EL device can be obtained. .

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of compound (16).

Continuing on the front page (72) Inventor Satoshi Okitsu 2-3-113 Kyobashi, Chuo-ku, Tokyo Inside Toyo Ink Manufacturing Co., Ltd. (72) Inventor Toshio Enoda 2-3-13-1 Kyobashi, Chuo-ku, Tokyo Toyo In Niki Manufacturing Co., Ltd.

Claims (8)

[Claims] 1. A luminescent material for an organic electroluminescence device represented by the following general formula [1]. General formula [1] [Wherein A ^{1 and} A ² each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted fused polycyclic group, Represents a substituted or unsubstituted alkylamino group or a substituted or unsubstituted arylamino group. R ^{1 to} R ¹⁶ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, Represents an unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (even if adjacent groups are bonded to each other to form a new ring, Good.) ] 2. A light-emitting material for an organic electroluminescence device represented by the following general formula [2]. General formula [2] [Wherein, A ^{3 to} A ⁶ each independently represent a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. R ^{1 to} R
¹⁶ are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkylthio Represents a group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (adjacent groups may be bonded to each other to form a new ring). ] 3. A light-emitting material for an organic electroluminescence device represented by the following general formula [3]. General formula [3] [Wherein, R ^{1 to} R ³⁶ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy Represents a group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (R ^{1 to} R ¹⁶ represent adjacent groups May combine to form a new ring.). ] 4. A light emitting material for an organic electroluminescence device represented by the following general formula [4]. General formula [4] [Wherein, R ^{1 to} R ¹⁶ and R ^{37 to} R ⁵⁶ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, Or an unsubstituted aryloxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (R ^{1 to} R ¹⁶
May be bonded to each other by adjacent groups to form a new ring. ). X ^{1 to} X ⁴ are each independently O, S, C ＝ O, SO ₂ , (CH ₂ ) x-O- (C
H ₂ ) represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted aliphatic ring group; Where x and y
Represents a positive integer from 0 to 20, but does not satisfy x + y = 0. ] 5. A light emitting material for an organic electroluminescence device represented by the following general formula [5]. General formula [5] [Wherein, R ^{1 to} R ¹⁶ and R ^{37 to} R ⁵⁶ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, Or an unsubstituted aryloxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted ring group, or a substituted or unsubstituted amino group (R ^{1 to} R ¹⁶
May be bonded to each other by adjacent groups to form a new ring. ). Y ^{1 to} Y ⁸ represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms and a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. Further, in Y ¹ and Y ^2, Y ³ and Y ^4, Y ⁵ and Y ^6, Y ⁷ and Y ^8, may form an aliphatic ring group having 5 to 7 carbon atoms substituted or unsubstituted. ] 6. An organic electroluminescence device in which a plurality of organic compound thin films including a light emitting layer are formed between a pair of electrodes, wherein at least one layer contains the organic electroluminescence device material according to any one of claims 1 to 5. An organic electroluminescence device. 7. An organic electroluminescent device in which a plurality of organic compound thin films including a light emitting layer are formed between a pair of electrodes, wherein the light emitting layer contains the organic electroluminescent device material according to claim 1. An organic electroluminescence device. 8. An organic electroluminescence device in which a plurality of organic compound thin films including a light emitting layer are formed between a pair of electrodes, wherein the light emitting layer comprises a host material and a doping material, wherein the doping material is one of the following. An organic electroluminescent element which is the organic electroluminescent element material according to any of the above.