JP3340687B2 - Organic electroluminescence device - Google Patents

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, an EL element includes a light-emitting layer and a pair of opposed electrodes sandwiching the light-emitting 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 a thin film containing an organic compound having high fluorescence quantum efficiency that emits light at a low voltage of 10 V or less is 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]

According to the present invention, there is provided an organic electroluminescent device comprising an anode / a hole injection layer / a light emitting layer / an electron injection layer / a cathode, wherein the light emitting layer is represented by the following general formula [1]. The hole injection layer is a layer containing an aromatic tertiary amine derivative or a phthalocyanine derivative represented by the following general formula [6], and the electron injection layer is a metal complex compound or The present invention relates to an organic electroluminescence device, which is a layer containing a nitrogen-containing five-membered ring derivative. General formula [1]

Embedded image [Wherein, A ^{1 to} A ⁴ represent a substituted or unsubstituted C 6
To 16 aryl groups. R ^{1 to} R ⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group. (Adjacent substituents are bonded together to form a new 6
It may form a membered aryl ring. ). General formula [6]

Embedded image [Wherein, B ^{1 to} B ⁴ each independently represent a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. Z represents a substituted or unsubstituted arylene group (however, excluding an anthracenylene group). ]

Further, the present invention is the above-mentioned organic electroluminescent device, wherein the luminescent material is a compound represented by the following general formula [2]. General formula [2]

Embedded image [Wherein, R ^{1 to} R ²⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted Represents an amino group. R ¹
To R ⁴ or R ⁵ to R ⁸ may form a new 6-membered aryl ring bonded with a substituent each other adjacent. ]

Further, the present invention is the above-mentioned organic electroluminescent device, wherein the luminescent material is a compound represented by the following general formula [3]. General formula [3]

Embedded image [Wherein, R ^{1 to} R ⁸ and R ^{29 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted amino group. X ^{1 to} X ⁴ are each independently O, S,
C = O, SO _2, represents a _{(CH 2) x-O- (} CH 2) y, a substituted or unsubstituted alkylene, substituted or unsubstituted aliphatic ring residue. Here, x and y each independently represent a positive integer of 0 to 20, but x + y = 0 does not occur. R ^{1 to} R ⁴ or R ^{5 to} R ⁸ may be bonded by adjacent substituents to form a new 6-membered aryl ring. ]

Further, the present invention is the above-mentioned organic electroluminescent device, wherein the luminescent material is a compound represented by the following general formula [4]. General formula [4]

Embedded image [Wherein, R ^{1 to} R ⁸ and R ^{29 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted amino group. X ^{1 to} X ⁴ are each independently O, S,
C = O, SO _2, represents a _{(CH 2) x-O- (} CH 2) y, a substituted or unsubstituted alkylene, substituted or unsubstituted aliphatic ring residue. Here, x and y each independently represent a positive integer of 0 to 20, but x + y = 0 does not occur. R ^{1 to} R ⁴ or R ^{5 to} R ⁸ may be bonded by adjacent substituents to form a new 6-membered aryl ring. ]

Further, the present invention is the above-mentioned organic electroluminescent device, wherein the luminescent material is a compound represented by the following general formula [5]. General formula [5]

Embedded image [Wherein, R ^{1 to} R ⁸ and R ^{29 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted amino group. 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. R ^{1 to} R ⁴ or R ⁵ to
R ⁸ may be linked by adjacent substituents to form a new 6-membered aryl ring. ]

Further, the present invention provides the above-mentioned metal complex compound,
The above organic electroluminescent device, which is a compound represented by the following general formula [7]: General formula [7]

Embedded image [Wherein Q ¹ and Q ² each independently represent a substituted or unsubstituted hydroxyquinoline derivative or a substituted or unsubstituted hydroxybenzoquinoline derivative, L represents a halogen atom, a substituted or unsubstituted alkyl group, A substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group which may contain a nitrogen atom,-
OR (R represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group which may contain a nitrogen atom.), -O-Ga-Q ³ ( Q ⁴ ) (Q ³ and Q
⁴ has the same meaning as Q ¹ and Q ² . ) Represents a ligand represented by ]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The substituted or unsubstituted aryl group having 6 to 16 carbon atoms in A ^{1 to} A ⁴ of the compound represented by the general formula [1] in the present invention includes a phenyl group,
It is an aryl group such as a biphenyl group, a terphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a fluorenyl group, a pyrenyl group and the like, and each aryl group may have a substituent. In the present invention, the aromatic carbon atom of the aryl group may be substituted by a nitrogen atom, an oxygen atom and / or 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 ¹ and A ² or A ³ and A ⁴ may be combined to form an aryl group containing a nitrogen atom such as a carbazole group.

In the present invention, R ^{1 to} R ⁴⁸ of the compounds represented by the general formulas [1] to [5] each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group,
Represents a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted amino group.

The substituents of A ^{1 to} A ⁴ and R ¹ to
Specific examples of R ^48, as the halogen atom are fluorine, chlorine, bromine, iodine, substituted or non-substituted alkyl group, a methyl group, an ethyl group, a propyl group, n- butyl group, sec- butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, unsubstituted linear or branched 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, α-dimethylbenzyl group, α,
There is a substituted or unsubstituted alkoxyl having an alkyl group having 1 to 20 carbon atoms such as α-methylphenylbenzyl group, α, α-ditrifluoromethylbenzyl group, triphenylmethyl group, α-benzyloxybenzyl group and the like. Examples of the group include a methoxy group, an ethoxy group, a propoxy group, and n
1 to 2 carbon atoms such as -butoxy group, tert-butoxy group, n-octyloxy group, tert-octyloxy group, etc.
In addition to 0 unsubstituted alkoxyl groups, there are substituted or unsubstituted alkoxyl groups having 1 to 20 carbon atoms such as 1,1,1-trifluoroethoxy group, phenoxy group, benzyloxy group, and octylphenoxy group. Examples of the aryl group include phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, biphenyl, 4-methylbiphenyl,
Substituted or unsubstituted C6-C18 aromatic carbon atoms such as ethylbiphenyl, 4-cyclohexylbiphenyl, terphenyl, 3,5-dichlorophenyl, naphthyl, 5-methylnaphthyl, anthryl and pyrenyl. Examples of the aryl group which has an aryl group and may have an aromatic carbon atom substituted by a nitrogen atom, an oxygen atom and / or a sulfur atom include a furanyl group, a thiophenyl group, a pyrrole group, a pyranyl group, a thiopyranyl group, a pyridinyl group, and a thiazolyl group. Group, imidazole group, pyrimidinyl group,
There are a triazinyl group, an indolinyl group, a quinolyl group, a purinyl group, and the like.Substituted or unsubstituted amino groups include amino groups, dimethylamino groups, dialkylamino groups such as diethylamino groups, phenylmethylamino groups, diphenylamino groups, and ditolylamino groups. And a dibenzylamino group. Adjacent substituents may be bonded to each other to form a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, or the like.

The general formulas [3] and [4] in the present invention
X ^{1 to} X ⁴ of the compound represented by are each independently
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 ring residue. Here, x and y each independently represent a positive integer of 0 to 20,
x + y = 0 never occurs. As a substituted or unsubstituted alkylene group, an alkylene group having 1 to 20 carbon atoms or a substituted product thereof, and as a substituted or unsubstituted aliphatic ring residue, a cyclopentyl ring, a cyclohexyl ring, a 4-methylcyclohexyl ring, a cycloheptyl ring 5-7 carbon atoms such as
And a divalent residue of an aliphatic ring. The substituent of the substituted alkylene group or the substituted aliphatic ring residue of X ^{1 to} X ⁴ is R
It is a substituent shown in ¹ to R ^{4 8.} Preferred as the substituted alkylene group for X ^{1 to} X ⁴ are a 2,2-propylene group,
Examples include a dichloromethylene group, a difluoromethylene group, a phenoxymethylene group, a methylphenylmethylene group, a diphenylmethylene group, and a benzyloxymethylene group.

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. Specific examples of the alkyl group and the aryl group include the alkyl groups and the aryl groups described for R ^{1 to} R ⁴⁸ above.

Among these compounds, general formulas [3] to [5]
Or a compound having a substituent having an aromatic ring represented by the general formula [1] to [5], wherein adjacent substituents of R ^{1 to} R ⁴⁸ 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.

An example of a method for synthesizing the compounds represented by the general formulas [1] to [5] of the present invention is shown below. The compounds of the general formulas [1] to [5] can be synthesized by reacting 9,10-dihalogenoanthracene, an optionally substituted amine derivative, potassium carbonate and a catalyst in a solvent.
It can also be synthesized from an anthraquinone derivative in place of 9,10-dihalogenoanthracene. Instead of potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, aqueous ammonia or the like can be used. Catalysts include copper powder, cuprous chloride, tin, stannous chloride, pyridine, aluminum trichloride or titanium tetrachloride. Solvents include benzene, toluene or xylene. The above synthesis method is not limited.

Hereinafter, typical examples of the compounds of the general formulas [1] to [5] of the present invention are specifically shown in Table 1, but the present invention is not limited to these typical examples.

[0020]

[Table 1]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

The compounds represented by the general formulas [1] to [5] of the present invention are compounds having strong fluorescence in a solid state and excellent in electroluminescence. In addition, since it has both excellent hole injecting property and hole transporting property from the metal electrode, and excellent electron injecting property and electron transporting property from the metal electrode, it can be effectively used as a light emitting material, Further, other hole transporting materials, electron transporting materials or doping materials may be used.

The organic EL device is a device in which a single or multilayer organic thin film is 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. However, the luminescent material of the present invention
Since it has extremely high emission quantum efficiency, high hole transport ability and electron transport ability and can form a uniform thin film, it is possible to form a light emitting layer using only the light emitting material of the present invention. The multilayer type includes (anode / hole injection layer / electron injection layer / cathode), (anode / hole injection layer / electron injection layer / cathode), and (anode / hole injection layer / light emission layer / electron injection layer / cathode) multilayer. There is an organic EL element stacked in a configuration. General formula [1]-
The compound of [5] has high light emitting properties, a hole injecting property,
Since it has a hole transporting property, an electron injecting property, and an electron transporting property, it can be used in a light emitting layer as a light emitting material.

In the light emitting layer, if necessary, in addition to the compounds of the general formulas [1] to [5] of the present invention, further known light emitting materials, doping materials, hole injection materials and electron injection materials are used. You can also. 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 a light emitting material, a doping material, a hole injection material, and an electron injection material can be used. Also, depending on the doping material,
It is also possible to improve light emission luminance and light emission efficiency and obtain red and blue light emission. Further, each of the hole injection layer, the light emitting layer, and the electron injection layer may be formed in a layer structure of two or more layers. In this case, in the case of a hole injection layer, a layer for injecting holes from the electrode is a hole injection layer, and a layer for receiving holes from the hole injection layer and transporting holes to the light emitting layer is a hole transport layer. Call. Similarly, in the case of an electron injection layer, a layer that injects electrons from the electrode is called an electron injection layer, and a layer that receives electrons from the electron injection layer and transports electrons to the light emitting layer is called an electron transport layer. Each of these layers
The material is selected and used depending on factors such as the energy level of the material, heat resistance, and adhesion to the organic layer or the metal electrode.

The hole injecting material has the ability to transport holes, has the effect of injecting holes from the anode, and has an excellent hole injecting effect on the light emitting layer or the light emitting material. Compounds that prevent excitons from migrating to the electron injection layer or the electron injection material and have excellent thin film forming ability are exemplified. Specifically, phthalocyanine derivatives, naphthalocyanine derivatives, porphyrin derivatives, oxazole, oxadiazole, triazole, imidazole, imidazolone, imidazolethione, pyrazoline, pyrazolone,
Tetrahydroimidazole, oxazole, oxadiazole, hydrazone, acylhydrazone, polyarylalkane, stilbene, butadiene, benzidine-type triphenylamine, styrylamine-type triphenylamine, diamine-type triphenylamine, and derivatives thereof, and polyvinyl carbazole , Polysilane, and a polymer material such as a conductive polymer, but are not limited thereto.

Among the hole injection materials that can be used in the organic EL device of the present invention, more effective hole injection materials include:
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.

Specific examples of B ^{1 to} B ⁴ of the compound represented by the general formula [6] in the present invention include phenyl group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, fluorenyl group and pyrenyl group. Or an aryl group in which an aromatic carbon atom may be substituted with a nitrogen atom, an oxygen atom and / or a sulfur atom, for example, a furanyl group, a thiophenyl group, a pyrrole group, and a pyranyl group , A thiopyranyl group,
Examples include a pyridinyl group, a thiazolyl group, an imidazole group, a pyrimidinyl group, a pyridinyl group, a triazinyl group, an indolinyl group, a quinolyl group, and a purinyl group. Each aryl group may have a substituent. Examples of the substituent include those exemplified as specific examples of R ^{1 to} R ⁴⁸ .

Z is a divalent arylene group, and includes a phenylenyl group, a biphenylenyl group, a terphenylenyl group, a naphthylenyl group, an anthrenyl group, a phenanthrenyl group, a fluorenylenyl group, a pyrenylenyl group, a furaniler group, a thiophenylyl group, a pyrrolell group, Pyraniler group,
Thiopyranylel, pyridinylel, thiazolylyl,
There is a divalent residue corresponding to an aryl group such as an imidazolinyl group, a pyrimidinylel group, a pyridinylel group, a triazinylyl group, an indolinylyl group, a quinolyl group, and a plinylel group. As the substituent, there are the substituents specifically exemplified as R ^{1 to} R ⁴⁸ .

Hereinafter, typical examples of the compound of the general formula [6] of the present invention and other materials which are more effective hole injecting materials are specifically shown in Table 2. It is not limited to a representative example.

[0040]

[Table 2]

[0041]

[0042]

[0043]

[0044]

The phthalocyanine (Pc) derivatives include:
H ₂ Pc, CuPc, CoPc, NiPc, ZnPc,
PdPc, FePc, MnPc, ClAlPc, ClG
aPc, ClInPc, ClSnPc, Cl ₂ SiP
c, (HO) AlPc, (HO) GaPc, VOPc,
Examples include, but are not limited to, phthalocyanine derivatives such as TiOPc, MoOPc, GaPc-O-GaPc, and naphthalocyanine derivatives.

The electron injecting material has the ability to transport electrons, has the effect of injecting electrons from the cathode, has an excellent electron transporting effect on the light emitting layer or the light emitting material, and has the positive effect of excitons generated in the light emitting layer. Compounds that prevent migration to the hole injection layer and have excellent thin film forming ability are mentioned. For example, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane,
Examples include, but are not limited to, anthrones and derivatives thereof. In addition, sensitization can be performed by adding an electron accepting substance to the hole injecting material and adding an electron donating substance to the electron injecting material.

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 organic EL device of the present invention, a more effective electron injecting material is a compound of the general formula [7], wherein Q ¹ and Q ^{4 in} the general formula [7] are 8-hydroxyquinoline,
8-hydroxyquinaldine, 8-hydroxy-2-phenylquinoline, 8-hydroxy-5-methylquinoline,
A hydroxyquinoline derivative such as 8-hydroxy-3,5,7-trifluoroquinoline, L represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted nitrogen atom. An aryl group which may be contained, -OR (R represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or an aryl group which may contain a substituted or unsubstituted nitrogen atom),- O-Ga-Q
³ (Q ⁴ ) (Q ³ and Q ⁴ represent the same meaning as Q ¹ and Q ² ). Here, a halogen atom, an alkyl group, an aryl group which may contain a nitrogen atom, and -O
The alkyl group of R in R group and the aryl group which may contain a nitrogen atom include R ¹ to R 5 described in the general formulas [1] to [5].
It represents a same group as R ^48. Examples of the substituted or unsubstituted cycloalkyl group include an unsubstituted cycloalkyl group having 5 to 7 carbon atoms such as a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group, or an alkyl group having 1 to 4 carbon atoms at any position of the cycloalkyl group. Groups or alkoxy groups, and cycloalkyl groups substituted by halogen atoms and the like.

Hereinafter, typical examples of the compound represented by the general formula [7] and typical examples of the electron injection material used in the organic EL device of the present invention are specifically shown in Table 3. It is not limited to the example.

[0050]

[Table 3]

[0051]

[0052]

[0053]

[0054]

[0055]

In the present organic EL device, the light emitting layer includes
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 the conductive material used for the anode of the organic EL element, those having a work function of more than 4 eV are suitable, and include carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, and platinum. , Palladium and their alloys, tin oxide used for ITO substrate, NESA substrate, metal oxide such as indium oxide,
Further, an organic conductive resin such as polythiophene or polypyrrole is used. As the conductive material used for the cathode, those having a work function smaller than 4 eV are suitable, and magnesium, calcium, tin, lead, titanium,
Yttrium, lithium, ruthenium, manganese, aluminum and the like and alloys thereof are used, but not limited thereto. 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 temperature, atmosphere, degree of vacuum, and the like of the evaporation source, and is selected to be an appropriate ratio. The anode and the cathode may be formed by two or more layers if necessary.

In the organic EL device, at least one of them is desirably 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 using the above-described conductive material so as to secure a predetermined translucency by a method such as vapor deposition or sputtering. 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 transparency, but, for example, a glass substrate, a polyethylene plate, a polyethylene terephthalate plate, a polyether sulfone plate, A transparent resin such as a polypropylene plate can be used.

Each layer of the organic EL device according to the present invention can be formed by any of dry film forming methods such as vacuum deposition, sputtering, plasma, and ion plating, and wet film forming methods such as spin coating, dipping and flow coating. Can be applied. The film thickness is not particularly limited, but needs to be set to an appropriate film 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. The normal film thickness is suitably in the range of 5 nm to 10 μm, but is more preferably in the range of 10 nm to 0.2 μm.

In the case of the wet film forming method, the material forming each layer is made of ethanol, chloroform, tetrahydrofuran,
The thin film is formed by dissolving or dispersing in a suitable solvent such as dioxane, and any solvent may be used. In any of the organic thin film layers, a suitable resin or additive may be used for improving film forming properties, preventing pinholes in the film, and the like. Examples of usable resins include insulating resins such as polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyurethane, polysulfone, polymethyl methacrylate, polymethyl acrylate, and cellulose, and copolymers thereof, and poly-N-vinyl. Examples thereof include photoconductive resins such as carbazole and polysilane, and conductive resins such as polythiophene and polypyrrole. Examples of the additive include an antioxidant, an ultraviolet absorber, and a plasticizer.

As described above, the compound of the present invention is used in the light-emitting layer of an organic EL device and further combined with a specific hole-injection layer or electron-injection layer to obtain an organic EL device having excellent luminous efficiency and maximum luminous brightness. 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.

[0064]

The present invention will be described in more detail with reference to the following examples. Method for synthesizing compound (1) 10 parts of anthraquinone, 35 parts of diphenylamine and 15 parts of pyridine were placed in 200 parts of benzene, and
At 40 ° C., 40 parts of titanium tetrachloride was added dropwise, and the mixture was stirred at room temperature for 20 hours. Thereafter, the mixture was diluted with 500 parts of water and neutralized with a dilute aqueous sodium hydroxide solution. Thereafter, extraction was performed with ethyl acetate, the mixture was concentrated, and purified by column chromatography using silica gel to obtain 8 parts of needle crystals having yellow fluorescence. As a result of molecular weight analysis, it was confirmed that the product was Compound (1). The results of elemental analysis of the product are shown below. Elemental analysis result: C ₃₈ H ₂₈ N ₂ Calculated value (%): C: 89.06 H: 5.47 N: 5.47 Actual value (%): C: 89.11 H: 5.55 N: 5 .34

Method for synthesizing compound (6) 25 parts of 9,10-dibromoanthracene, 4,4-di-
100 parts of n-octyldiphenylamine, 40 parts of potassium carbonate, 2 parts of copper powder, and 2 parts of cuprous chloride were added, and heated and stirred at 210 ° C. for 30 hours in 80 parts of nitrobenzene. Thereafter, the mixture was diluted with 500 parts of water and extracted with chloroform. The chloroform layer was concentrated, purified by column chromatography using silica gel, and reprecipitated with n-hexane to obtain 28 parts of a powder having yellow fluorescence. As a result of molecular weight analysis, it was confirmed to be Compound (6). The results of elemental analysis of the product are shown below. Elemental analysis result: C ₇₀ H ₉₂ N ₂ Calculated value (%): C: 87.50 H: 9.58 N: 2.92 Actual value (%): C: 87.52 H: 9.53 N: 2 .95

Method for synthesizing compound (23) 15,10-diiodoanthracene 15 parts, 4,4-di (2-phenylisopropyl)) diphenylamine 27
And 12 parts of potassium carbonate and 0.8 part of copper powder, and the mixture was heated and stirred at 200 ° C. for 30 hours. Then 50
It was diluted with 0 parts of water and extracted with chloroform. The chloroform layer was concentrated and purified by column chromatography using silica gel to give n-
The precipitate was reprecipitated with hexane to obtain 18 parts of a powder having a yellow fluorescence. As a result of molecular weight analysis, it was confirmed to be Compound (23). The results of elemental analysis of the product are shown below. Elemental analysis result: C ₇₄ H ₆₈ N ₂ Calculated value (%): C: 90.24 H: 6.91 N: 2.85 Actual value (%): C: 90.59 H: 6.81 N: 2 .60

Method for synthesizing compound (33) 12 parts of 9,10-diiodoanthracene, 25 parts of 1-naphthyl-phenylamine, 20 parts of potassium carbonate,
0.6 part of copper powder was added and heated and stirred at 200 ° C. for 30 hours. Then, the mixture was diluted with 600 parts of water and extracted with chloroform. The chloroform layer was concentrated, purified by column chromatography using silica gel, and recrystallized with n-hexane to obtain 27 parts of needle crystals having yellow fluorescence. As a result of molecular weight analysis, it was confirmed to be Compound (33). The results of elemental analysis of the product are shown below. Elemental analysis result: C ₄₆ H ₃₂ N ₂ Calculated value (%): C: 90.20 H: 5.23 N: 4.57 Actual value (%): C: 90.39 H: 5.31 N: 4 .30

Example 1 A compound (3) of 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 and a polycarbonate resin (Teijin Kasei: Panlite K-1300) were dissolved in tetrahydrofuran at a weight ratio of 5: 3: 2, and a 100 nm-thick light emitting layer was obtained by spin coating. . An electrode having a thickness of 150 nm was formed thereon with an alloy of magnesium and silver mixed at a ratio of 10: 1 to obtain an organic EL device. The light emission characteristics of this element are 120 (cd /
m ² ), maximum luminance 1200 (cd / m ²⁾ , luminous efficiency 0.
Green light emission of 70 (lm / W) was obtained.

Example 2 A compound (10) shown in Table 1 was vacuum-deposited on a washed glass plate with an ITO electrode to form a 100 nm-thick light-emitting layer, on which magnesium and silver were mixed at a ratio of 10: 1. An electrode having a thickness of 100 nm was formed from the mixed alloy to obtain an organic EL device. The light emitting layer was deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This element is 4
00 (cd / m ² ), maximum brightness 1200 (cd / m ² )
m ² ) and green light emission having a luminous efficiency of 0.50 (lm / W) was obtained.

Example 3 A compound (6) shown in Table 1 was dissolved in methylene chloride on a washed glass plate with an ITO electrode, and a 50 nm-thick light emitting layer was obtained by spin coating. Next, the compound (B-10) shown in Table 3 was vacuum-deposited to form an electron-injection layer having a thickness of 10 nm, and magnesium and silver were further added thereon by 10:
An electrode having a thickness of 100 nm was formed from the alloy mixed in Step 1 to obtain an organic EL device. The light emitting layer and the electron injection layer are 10 ^-6 T
Vapor deposition was performed at a substrate temperature of room temperature in a vacuum of orr.
This device has a DC voltage of 5 V, 300 (cd / m ² ), a maximum luminance of 2200 (cd / m ² ), and a luminous efficiency of 0.90 (l).
m / W).

Example 4 A compound (6) shown in Table 1 was vacuum-deposited on a washed glass plate with an ITO electrode to form a 50 nm-thick light emitting layer. Next, a compound (B-10) shown in Table 3 was vacuum-deposited to form an electron injection layer having a thickness of 10 nm, and an alloy obtained by mixing magnesium and silver at a ratio of 10: 1 to a thickness of 100 nm.
Was formed to obtain an organic EL device. The electron injection layer and the light emitting layer were deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This device has a DC voltage of 5 V and
0 (cd / m ² ), maximum brightness 11,000 (cd / m ² )
m ² ) and green luminescence with a luminous efficiency of 1.05 (lm / W) was obtained.

Examples 5 to 47 On a cleaned glass plate with ITO electrodes, under the conditions shown in Table 4,
The hole injection material was vacuum-deposited to obtain a hole injection layer having a thickness of 30 nm. Next, a luminescent material is vacuum-deposited to a thickness of 30 n.
m light emitting layers were obtained. Further, an electron injecting material is vacuum-deposited to form an electron injecting layer having a thickness of 30 nm, and an electrode having a thickness of 150 nm is formed on the electron injecting layer with an alloy of magnesium and silver mixed at a ratio of 10: 1. I got Each layer is 10
Vapor deposition was performed at a substrate temperature of room temperature in a vacuum of ^-6 Torr. Table 4 shows the emission characteristics of this device. The emission luminance here is the luminance when a DC voltage of 5 V is applied, and all the organic EL elements of this embodiment have a maximum luminance of 10,000 (cd / m ² ).
It had the above high luminance characteristics. As the light emitting material represented by the general formula [1], those having an aryl group as a substituent of A ^{1 to} A ⁴ or a compound forming an aromatic ring with adjacent substituents have a glass transition point. The temperature and the melting point were high, and the initial luminance and life characteristics when light emission was driven were good. Further, as the element configuration of the organic EL element,
An element in which the hole injection material of the general formula [6] and the electron injection material of the general formula [7] were combined with the light emitting materials of the general formulas [1] to [5] exhibited the best characteristics.

[0073]

[Table 4]

Example 48 A hole injecting material (A-16) was vacuum-deposited on a washed glass plate with an ITO electrode to obtain a hole injecting layer having a thickness of 20 nm. Next, the compound (23) was vacuum-deposited as a light emitting material to obtain a light emitting layer having a thickness of 20 nm. Further, (B-23) was vacuum-deposited as an electron injecting material to a thickness of 20
nm was obtained. An electrode having a thickness of 150 nm was formed thereon with an alloy of magnesium and silver mixed at a ratio of 10: 1 to obtain an organic EL device. This element has a DC voltage of 5 V
770 (cd / m ² ) and a maximum luminance of 27000 (cd / m ² ).
m ² ) and green light emission having a light emission efficiency of 1.8 (lm / W) was obtained.

Example 49 A hole injection layer having a thickness of 5 nm made of metal-free phthalocyanine was provided between the ITO electrode and the compound (A-16).
An organic EL device was manufactured in the same manner as in Example 48. This device has a DC voltage of 5 V, 1200 (cd / m ² ), a maximum luminance of 29000 (cd / m ² ), and a luminous efficiency of 1.70.
Green light emission of (lm / W) was obtained.

Example 50 A hole injecting material was placed on a washed glass plate with ITO electrodes.
(A-4) is vacuum-deposited to form a 30-nm-thick hole injection layer.
Obtained. Next, a hole injection material (A-13) is vacuum-deposited.
Thus, a second hole injection layer having a thickness of 10 nm was obtained. Then departure
Compound (24) is vacuum-deposited as an optical material to a film thickness of 30 n
m light emitting layers were obtained. Further, an electron injection material (B-12)
Was vacuum-deposited to obtain an electron injection layer having a thickness of 30 nm. That
A film made of an alloy of magnesium and silver mixed at a ratio of 10: 1
An electrode having a thickness of 150 nm was formed to obtain an organic EL device. This
Has a light emission luminance of 1100 (cd /
m^Two), Maximum emission luminance 87000 (cd / m^Two), Luminous efficacy
Green light emission at a rate of 9.3 (lm / W) was obtained. Example 51 Metal-free phthalocyanine in place of compound (A-16)
Example 48 except that a hole injection layer having a thickness of 20 nm was provided.
An organic EL device was produced in the same manner as in the above. This element
650 (cd / m) at DC voltage 5V^Two), Maximum brightness 150
00 (cd / m ^Two), With a luminous efficiency of 1.30 (lm / W)
Green emission was obtained.

The organic EL devices shown in this example had a light emission luminance of 10,000 (cd / m ² ) or more, and all were able to obtain high light emission efficiency. When the organic EL device shown in this example was continuously emitted at 3 (mA / cm ² ), stable light emission could be observed for 1000 hours or more, and almost no dark spot was observed. Thus, in the organic EL device of the comparative example, the light emission luminance was less than half of the initial light emission luminance in the light emission time of 500 hours or less, many dark spots were observed, and the number increased and increased with the light emission time. Since the organic EL device using the organic EL device material of the present invention has an extremely high fluorescence quantum efficiency of the light emitting material, the device using this light emitting material can emit light with high luminance in a low current application region. .

The organic EL device of the present invention achieves an improvement in luminous efficiency, luminous luminance, and a long life, and is used together with a luminescent material, a doping material, a hole injection material, an electron injection material, and a sensitizer. It does not limit the agent, resin, electrode material and the like, and the element manufacturing method.

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. . Using the compound shown in the present invention as described above in at least one layer of an organic EL device, and
With the organic EL device formed by the device configuration of the present invention, an organic EL device having high luminance, high luminous efficiency, and long life can be easily manufactured.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H05B 33/22 H05B 33/22 BD (56) References JP-A-4-178487 (JP, A) JP-A-5-78655 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) C09K 11/06 CA (STN) REGISTRY (STN)

Claims (6)

(57) [Claims] 1. An organic electroluminescence device comprising an anode / a hole injection layer / a light emitting layer / an electron injection layer / a cathode, wherein the light emitting layer is a layer containing a light emitting material represented by the following general formula [1]. The hole injection layer is a layer containing an aromatic tertiary amine derivative or a phthalocyanine derivative represented by the following general formula [6], and the electron injection layer is containing a metal complex compound or a nitrogen-containing five-membered ring derivative. An organic electroluminescent device, wherein the organic electroluminescent device comprises General formula [1] [Wherein, A ^{1 to} A ⁴ each independently represent a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. R ^{1 to} R
⁸ independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group (neighboring substituted Groups may be joined together to form a new 6-membered aryl ring.). General formula [6] [Wherein, B ^{1 to} B ⁴ each independently represent a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. Z represents a substituted or unsubstituted arylene group (however, excluding an anthracenylene group). ] 2. The organic electroluminescence device according to claim 1, wherein the light emitting material is a compound represented by the following general formula [2]. General formula [2] [Wherein, R ^{1 to} R ²⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted Represents an amino group. R ¹
To R ⁴ or R ⁵ to R ⁸ may form a new 6-membered aryl ring bonded with a substituent each other adjacent. ] 3. The organic electroluminescent device according to claim 2, wherein the light emitting material is a compound represented by the following general formula [3]. General formula [3] [Wherein, R ^{1 to} R ⁸ and R ^{29 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted amino group. X ^{1 to} X ⁴ are each independently O, S,
C = O, SO _2, represents a _{(CH 2) x-O- (} CH 2) y, a substituted or unsubstituted alkylene, substituted or unsubstituted aliphatic ring residue. Here, x and y each represent a positive integer of 0 to 20, but x + y = 0 does not occur. R ^{1 to} R ⁴ or R ^{5 to} R ⁸ may be bonded by adjacent substituents to form a new 6-membered aryl ring. ] 4. The organic electroluminescent device according to claim 3, wherein the light emitting material is a compound represented by the following general formula [4]. General formula [4] [Wherein, R ^{1 to} R ⁸ and R ^{29 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted amino group. X ^{1 to} X ⁴ are each independently O, S,
C = O, SO _2, represents a _{(CH 2) x-O- (} CH 2) y, a substituted or unsubstituted alkylene, substituted or unsubstituted aliphatic ring residue. Here, x and y each represent a positive integer of 0 to 20; however, x + y = 0 does not occur. R ^{1 to} R ⁴ or R ^{5 to} R ⁸ may be bonded by adjacent substituents to form a new 6-membered aryl ring. ] 5. The organic electroluminescent device according to claim 4, wherein the light emitting material is a compound represented by the following general formula [5]. General formula [5] [Wherein, R ^{1 to} R ⁸ and R ^{29 to} R ⁴⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted amino group. 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. R ^{1 to} R ⁴ or R ⁵ to
R ⁸ may be linked by adjacent substituents to form a new 6-membered aryl ring. ] 6. The organic electroluminescent device according to claim 1, wherein the metal complex compound is a compound represented by the following general formula [7]. General formula [7] [Wherein Q ¹ and Q ² each independently represent a substituted or unsubstituted hydroxyquinoline derivative or a substituted or unsubstituted hydroxybenzoquinoline derivative;
Is a halogen atom, a substituted or unsubstituted alkyl group,
A substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group optionally containing a nitrogen atom, -OR
(R represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or an aryl group which may contain a substituted or unsubstituted nitrogen atom.)
—O—Ga—Q ³ (Q ⁴ ) (Q ³ and Q ⁴ represent the same meaning as Q ¹ and Q ² ). ]