JPH10302961A - Electrolumescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroluminescent element with high luminance, good luminescent performance sustained for a long time and excellent durability by using specified indigo derivatives for a luminescent layer. SOLUTION: In a formula, R1 -R18 are independently hydrogen atoms, halogen atoms, hydroxyl groups, mercaptal groups, cyano groups, amino groups, nitro groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted alkylthio groups, substituted or unsubstituted N-monoalkylamino groups, substituted or unsubstituted N,N- dialkylamoino groups, substituted or unsubstituted aryl groups, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylthio groups or substituted or unsubstituted heterocyclic groups. Adjacent substitutional groups are coupled together to form substituted or unsubstituted aromatic cycles or substituted or unsubstituted heterocycles. Z1 and Z2 are indigo derivatives showing independently oxygen atoms, sulfur atoms or dicryanometylene groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electroluminescent device containing an indigo derivative.

[0002]

2. Description of the Related Art An electroluminescent (EL) device using an organic compound is disclosed in Tang et al.
Metal complex as light emitting layer, amine compound as charge transport layer,
In a structure in which two thin films are stacked, high-luminance light was obtained at a low voltage of 10 V or less (Appl. Phys. L).
ett. , 51 (12), 913 (1987))
It has attracted attention as a flat light source as a backlight of a liquid crystal display and a next-generation large-area full-color display device, and has been actively developed in recent years.

[0003] However, up to now, an element exhibiting sufficient luminance and stable light emission for a long period of time has not been obtained, and further improvement in luminance and improvement in durability of the element are required.

[0004]

SUMMARY OF THE INVENTION It is a main object of the present invention to provide an electroluminescent device having high luminance and excellent durability, which maintains good light emitting performance for a long period of time.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, the following general formula (1)

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[Wherein, R₁~ R₁₈Are each independently water
Elemental atom, halogen atom, hydroxyl group, mercapto group, cyano
Group, amino group, nitro group, substituted or unsubstituted alkyl
A substituted or unsubstituted alkoxy group, substituted or unsubstituted
Is an unsubstituted alkylthio group, a substituted or unsubstituted N-
Monoalkylamino group, substituted or unsubstituted N, N-
Dialkylamino group, substituted or unsubstituted aryl
Group, substituted or unsubstituted aryloxy group,
Or unsubstituted arylthio group or substituted or unsubstituted
Represents a heterocyclic group. However, further adjacent substituents
And a substituted or unsubstituted aromatic ring or substituted
Alternatively, an unsubstituted heterocyclic ring may be formed. Z ₁And Z_Two
Is independently an oxygen atom, a sulfur atom or dicia
Indicates a nomethylene group. Using a compound represented by the formula
The electroluminescent element shows high emission brightness
And stable for long-term use
Thus, the present invention has been achieved.

That is, the present invention provides the following general formula (1)

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Wherein R ₁ , R ₁₈ , Z ₁ and Z ₂ have the same meaning as described above. ] The use of the indigo derivative represented by the formula (1) in a light-emitting layer is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The synthesis of the compound represented by the general formula (1) of the present invention, wherein Z ₁ and Z ₂ are oxygen atoms, can be synthesized, for example, by the method described in Synthetic Synthetic Dyes (Hiroguchi Hiroshi, Sankyo Publishing, 1970, p. 472). Can be synthesized according to

That is, the following general formula (2)

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Wherein R _{1 to} R ₈ have the same meaning as described above. The indigo derivative represented by the following general formula (3)

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Wherein R _{9 to} R ₁₈ have the same meaning as described above. After heating and refluxing for about 0.5 to 2 hours together with the phenylacetic acid chloride derivative represented by the formula (1), the reaction mixture is diluted with nitrobenzene, cooled, and the crystallized product is filtered.

The conversion of Z ₁ or Z _{2 to} a sulfur atom can be carried out, for example, by the general formula (1) wherein Z ₁ and Z ₂ are oxygen atoms.
Can be reacted with hydrogen sulfide.
This reaction is usually performed in a solvent such as methanol, ethanol, acetic acid, ethyl acetate, dioxane, and diethyl ether.
By passing hydrogen sulfide and hydrogen chloride gas at -30 ° C to 30 ° C for about 0.5 to 4 hours.

The introduction of the dicyanomethylene group of Z ₁ or Z ₂ can be obtained, for example, by reacting the compound represented by the general formula (1) wherein Z ₁ and Z ₂ are oxygen atoms with malononitrile. This reaction is usually carried out in a solvent such as methanol, ethanol, propanol, diethyl ether, pyridine, tetrahydrofuran, sodium ethoxide,
The reaction can be carried out at a temperature of 20 ° C. to 100 ° C. for about 0.5 to 8 hours in the presence of a catalyst such as sodium methoxide and triethylamine. Of course, it can also be synthesized by other methods.

In the compound represented by the general formula (1) of the present invention, the substituents represented by R _{1 to} R ₁₈ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a mercapto group,
Cyano group, amino group, nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted N-monoalkylamino group, substituted or unsubstituted It represents an N, N-dialkylamino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, or a substituted or unsubstituted heterocyclic group. However, adjacent substituents may be bonded to each other to form a substituted or unsubstituted aromatic ring or a substituted or unsubstituted heterocyclic ring.

Z ₁ and Z ₂ each independently represent an oxygen atom, a sulfur atom or a dicyanomethylene group.

Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Specific examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, a 1-methylethyl group, a butyl group, a 1-methylpropyl group,
Methylpropyl group, 1,1-dimethylethyl group, pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-
Methylbutyl group, 1,1-dimethylpropyl group, 1,2
-Dimethylpropyl group, 2,2-dimethylpropyl group,
1-ethylpropyl group, 2-ethylpropyl group, hexyl group, cyclohexyl group, heptyl group, methylcyclohexyl group, octyl group, 2-ethylhexyl group, ethylcyclohexyl group, dimethylcyclohexyl group, nonyl group, 3,5,5- A linear, branched or cyclic alkyl group having 1 to 10 carbon atoms such as a trimethylhexyl group and a decyl group;
Benzyl group, phenylethyl group, tolylmethyl group, methoxyphenylmethyl group, naphthylmethyl group, aralkyl group such as naphthylethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, chloromethyl group,
Dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl, methyl iodide, fluoroethyl, difluoroethyl, trifluoroethyl, tetrafluoroethyl, pentafluoroethyl, hexafluoro -1-methylethyl group, a linear, branched, or cyclic halogenated alkyl group having 1 to 10 carbon atoms in which 1 to 21 halogen atoms such as a trifluoromethylcyclohexyl group are substituted, a methoxymethyl group,
Ethoxymethyl group, 2-methoxyethyl group, 2-ethoxyethyl group, 2-propoxyethyl group, 2- (1-methylethoxy) ethyl group, 2-butoxyethyl group, 2-hexyloxyethyl group, 2-cyclohexyloxy Ethyl group, 3-methoxypropyl group, 2-methoxy-1-methylethyl group, 3-ethoxypropyl group, 2-ethoxy-1-methylethyl group, 2- (2-methoxyethoxy)
A linear, branched or cyclic alkoxyalkyl group having 1 to 10 carbon atoms such as an ethyl group, a 2- (2-ethoxyethoxy) ethyl group, a methylthiomethyl group, an ethylthiomethyl group;
2-methylthioethyl group, 2-ethylthioethyl group, 2
-Propylthioethyl group, 2- (1-methylethylthio) ethyl group, 2-butylthioethyl group, 2- (1-methylpropylthio) ethyl group, 2- (1,1-dimethylethylthio) ethyl group , 2-hexylthioethyl group, 2
-Cyclohexylthioethyl group, 3-methylthiopropyl group, 1-methyl-2-methylthioethyl group, 3-ethylthiopropyl group, 2-ethylthio-1-methylethyl group, 2-propylthiopropyl group, 1-methyl- 2-propylthioethyl group, 2- (2-methylthioethoxy)
A linear, branched or cyclic alkylthioalkyl group having 1 to 10 carbon atoms such as an ethyl group, a 2- (2-ethylthioethylthio) ethyl group, an N-methylaminomethyl group, an N-methylaminoethyl group, An N-dimethylaminomethyl group,
Examples thereof include a linear, branched or cyclic N-alkylaminoalkyl group having 1 to 10 carbon atoms, such as an N, N-diethylaminomethyl group and an N, N-diethylaminoethyl group, and an N, N-dialkylaminoalkyl group.

Specific examples of the substituted or unsubstituted alkoxy group include methoxy, ethoxy, propoxy, 1-methylethoxy, butoxy, 1-methylpropoxy, 2-methylpropoxy, 1,1 -Dimethylethoxy group, pentyloxy group, 1-methylbutoxy group, 2-methylbutoxy group, 3-methylbutoxy group,
1,1-dimethylpropoxy group, 1,2-dimethylpropoxy group, 2,2-dimethylpropoxy group, 1-ethylpropoxy group, 3-ethylpropoxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group, methylcyclohexyl Oxy group, octyloxy group, 2-
C1-C10 linear, branched or cyclic alkyloxy group such as ethylhexyloxy group, ethylcyclohexyloxy group, dimethylcyclohexyloxy group, nonyloxy group, 3,5,5-trimethylhexyloxy group, decyloxy group, benzyl Oxy group, aralkyloxy group such as 2-phenylethoxy group, fluoromethoxy group, difluoromethoxy group, trifluoromethoxy group,
A halogen atom such as a chloromethoxy group, a dichloromethoxy group, a trichloromethoxy group, a bromomethoxy group, a dibromomethoxy group, a tribromomethoxy group, a methoxy iodide group, a chloroethoxy group, or a dichloroethoxy group;
A substituted, straight-chain, branched, or cyclic alkyloxy group having 1 to 10 carbon atoms, a methoxymethoxy group, an ethoxymethoxy group, a 2-methoxyethoxy group, a 2-ethoxyethoxy group, a 2-propoxyethoxy group, A linear, branched or cyclic alkoxyalkoxy group having 1 to 10 carbon atoms such as (1-methylethoxy) ethoxy group, 2-butoxyethoxy group, etc., N-methylaminomethoxy group, N, N-dimethylaminomethoxy group, N , N-diethylaminomethoxy group, N, N-diethylaminoethoxy group and the like, and linear, branched or cyclic N-alkylaminoalkyl groups having 1 to 10 carbon atoms, and N, N-dialkylaminoalkyl groups.

Specific examples of the substituted or unsubstituted alkylthio groups include methylthio, ethylthio, propylthio, 1-methylethylthio, butylthio,
-Methylpropylthio group, 3-methylpropylthio group,
1,1-dimethylethylthio group, pentylthio group, 1-
Methylbutylthio group, 2-methylbutylthio group, 3-methylbutylthio group, 1,1-dimethylbutylthio group,
1,2-dimethylbutylthio group, 2,2-dimethylbutylthio group, 1-ethylpropylthio group, 2-ethylpropylthio group, hexylthio group, cyclohexylthio group,
A heptylthio group, a methylcyclohexylthio group, an octylthio group, a 2-ethylhexylthio group, an ethylcyclohexylthio group, a dimethylcyclohexylthio group, a nonylthio group, a linear, branched or cyclic alkylthio group having 1 to 10 carbon atoms such as a decylthio group; Aralkylthio groups such as benzylthio, phenylethylthio, methoxyphenylmethylthio, etc., fluoromethylthio, difluoromethylthio, trifluoromethylthio, chloromethylthio, dichloromethylthio, trichloromethylthio, bromomethylthio, and fluoroethylthio Group, difluoroethylthio, trifluoroethylthio, tetrafluoroethylthio, pentafluoroethylthio, hexafluoro-1-methylethylthio, trifluoromethylcyclo Linear of 1 to 10 carbon atoms in which halogen atoms such as cyclohexylthio group has 1 to 21 amino substituted, branched, cyclic halogenated alkylthio group, methoxymethyl thio group,
Ethoxymethylthio, 2-methoxyethylthio, 2
-Ethoxyethylthio, 2-propoxyethylthio, 2- (1-methylethoxy) ethylthio, 2-butoxyethylthio, 2-hexyloxyethylthio, 2-cyclohexyloxyethylthio, 2-methoxy Propylthio group, 2-methoxy-1-methylethylthio group, 2-ethoxypropylthio group, 2-ethoxy-
A linear, branched or cyclic C1-C10 alkoxyalkylthio group, such as a 1-methylethylthio group, a 2- (2-methoxyethoxy) ethylthio group, or a 2- (2-ethoxyethoxy) ethylthio group, a methylthiomethylthio group ,
Ethylthiomethylthio, 2-methylthioethylthio, 2-ethylthioethylthio, 2-propylthioethylthio, 2- (1-methylethylthio) ethylthio, 2-butylthioethylthio, 2- (1-methylpropylthio) ethylthio group, 2- (1,1-dimethylethylthio) ethylthio group, 2-hexylthioethylthio group, 2-cyclohexylthioethylthio group, 2-methylthiopropylthio group, 1-methyl -2-methylthioethylthio group, 2-ethylthiopropylthio group, 2-ethylthio-1-methylethylthio group, 2-propylthiopropylthio group, 1-methyl-2-propylthioethylthio group, 2- ( 2-methylthioethoxy) ethylthio group, 2
A straight-chain, branched or cyclic alkylthioalkylthio group having 1 to 10 carbon atoms, such as-(2-ethylthioethylthio) ethylthio group, N-methylaminomethylthio group, N-methylaminoethylthio group, N, N-dimethyl Aminomethylthio group, N, N-diethylaminomethylthio group, N, N
A straight-chain, branched or cyclic N-alkylaminoalkylthio group having 1 to 10 carbon atoms, such as a diethylaminoethylthio group, and an N, N-dialkylaminoalkylthio group.

Specific examples of the substituted or unsubstituted N-monoalkylamino group include a methylamino group, an ethylamino group, a propylamino group, a 1-methylethylamino group, a butylamino group, and a 1-methylpropylamino group. , 2
-Methylpropylamino group, 1,1-dimethylethylamino group, pentylamino group, 1-methylbutylamino group, 2-methylbutylamino group, 3-methylbutylamino group, 1,1-dimethylbutylamino group, 1 , 2-dimethylbutylamino group, 2,2-dimethylbutylamino group, 1-ethylpropylamino group, 2-ethylpropylamino group, hexylamino group, cyclohexylamino group, heptylamino group, methylcyclohexylamino group, octylamino Group, 2-ethylhexylamino group,
1 to 10 carbon atoms such as an ethylcyclohexylamino group, a dimethylcyclohexylamino group, a nonylamino group, a 3,5,5-trimethylhexylamino group, and a decylamino group
Linear, branched or cyclic alkylamino group, benzylamino group, phenylethylamino group, aralkylamino group such as methoxyphenylmethylamino group, methoxymethylamino group, ethoxymethylamino group, 2-methoxyethylamino group, 2 -Ethoxyethylamino, 2-propoxyethylamino, 2- (1-methylethoxy) ethylamino, 2-butoxyethylamino, 2-hexyloxyethylamino, 2-cyclohexyloxyethylaminoamino, 2 -Methoxypropylamino group, 2-methoxy-1-methylethylamino group, 2-ethoxypropylamino group, 2-ethoxy-1-methylethylamino group, 2- (2-methoxyethoxy) ethylamino group, 2- ( 1 to 10 carbon atoms such as 2-ethoxyethoxy) ethylamino group Linear, branched or cyclic alkoxyalkylamino group, methylthiomethylamino group, ethylthiomethylamino group, 2-methylthioethylamino group, 2-ethylthioethylamino group, 2-propylthioethylamino group, etc. 10 to 10 linear, branched or cyclic alkylthioalkylamino groups, N-methylaminomethylamino groups, N-methylaminoethylamino groups,
A linear, branched or cyclic C-C10 N-alkylaminoalkylamino group such as an N, N-dimethylaminomethylamino group, an N, N-diethylaminomethylamino group, an N, N-diethylaminoethylamino group; And N, N-dialkylaminoalkylamino groups.

Specific examples of the substituted or unsubstituted N, N-dialkylamino group include N, N-dimethylamino group, N, N-diethylamino group, N, N-dipropylamino group, N, N- A di (1-methylethyl) amino group,
N, N-dibutylamino group, N, N-di (1-methylpropyl) amino group, N, N-di (2-methylpropyl)
Amino group, N, N-di (1,1-dimethylethyl) amino group, N, N-di (pentyl) amino group, N, N-di (1-methylbutyl) amino group, N, N-di (3 -Methylbutyl) amino group, N, N-di (1,1-dimethylbutyl) amino group, N, N-di (1,2-dimethylbutyl) amino group, N, N-di (2,2-dimethylbutyl) )
Amino group, N, N-di (1-ethylpropyl) amino group, N, N-di (2-ethylpropyl) amino group, N-
Ethyl-N-methylamino group, N-methyl-N-propylamino group, N-butyl-N-methylamino group, N-methyl-N- (1-methylpropyl) amino group, N-methyl-N- ( 2-methylpropyl) amino group, N-methyl-N-pentylamino group, N- (1-methylbutyl)-
N-methylamino group, N-hexyl-N-methylamino group, N-heptyl-N-methylamino group, N-octyl-N-methylamino group, N- (2-ethylhexyl)-
N-methylamino group, N-methyl-N-nonylamino group, N-ethyl-N-propylamino group, N-ethyl-
C1-C1 such as N-butylamino group, N-ethyl-N- (1-methylpropyl) amino group, N-ethyl-N-pentylamino group, N-ethyl-N-octylamino, etc.
0 linear, branched or cyclic alkyldi-substituted amino groups,
N, N-di (methoxymethyl) amino group, N, N-di (ethoxymethyl) amino group, N, N-di (2-methoxyethyl) amino group, N, N-di (2-ethoxyethyl) amino Group, N, N-di (2-propoxyethyl) amino group, N, N-di (2- (1-methylethoxy) ethyl) amino group, N, N-di (2-butoxyethyl) amino group, N , N-di (3-methoxypropyl) amino group,
N-methyl-N- (methoxymethyl) amino group, N-
1 carbon atom such as (ethoxymethyl) -N-methylamino group
Di-substituted amino group substituted with 10 to 10 linear, branched or cyclic alkoxy groups, N, N-di (methylthiomethyl)
Amino group, N, N-di (ethylthiomethyl) amino group,
N, N-di (2-methylthioethyl) amino group, N, N
-Di (2-ethylthioethyl) amino group, N, N-di (2-propylthioethyl) amino group, N, N-di (2
-(1-methylethylthio) ethyl) amino group, N, N
-Di (2-butylthioethyl) amino group, N- (2-hexylthioethyl) -N-methylamino group, N, N-di (2-methylthiopropyl) amino group, N- (2-methylthiopropyl) N, N-di (alkylthio) substituted by a linear, branched or cyclic alkylthioalkyl group having 1 to 10 carbon atoms such as -N-methylamino group, N- (2-cyclohexylthioethyl) -N-methylamino group. Alkyl) amino group or N-alkylthioalkyl-N-alkylamino group, N, N-di (N-methylaminomethyl) amino group, N, N-di (N-methylaminoethyl)
Examples thereof include a linear, branched, or cyclic N-alkylaminoalkyl group having 1 to 10 carbon atoms such as an amino group or a di-substituted amino group substituted with an N, N-dialkylaminoalkyl group.

Specific examples of the substituted or unsubstituted aryl groups include phenyl, naphthyl, anthranyl, 2-methylphenyl, 3-methylphenyl,
-Methylphenyl group, 2,3-dimethylphenyl group,
2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 3,6-dimethylphenyl group, 2, 3,4-trimethylphenyl group, 2-ethylphenyl group, 4-propylphenyl group,
2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 8-methyl-1-
Naphthyl group, 1-methyl-2-naphthyl group, 3-methyl-2-naphthyl group, 5-methyl-2-naphthyl group, 8-
An aryl group substituted by a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms such as a methyl-2-naphthyl group;
Methoxyphenyl group, 2,3-dimethoxyphenyl group,
2,3,4-trimethoxyphenyl group, 2-ethoxyphenyl group, 4-propoxyphenyl group, 2-methoxy-
1-naphthyl group, 4-methoxy-1-naphthyl group, 5-
A methoxy-1-naphthyl group, a 1-methoxy-2-naphthyl group, a 6-methyloxy-2-naphthyl group, etc.
Aryl, fluorophenyl, difluorophenyl, trifluorophenyl, chlorophenyl, dichlorophenyl, trichlorophenyl, bromophenyl, dibromophenyl, iodophenyl substituted with 10 linear, branched or cyclic alkoxy groups Aryl group substituted by a halogen atom such as a group, aryl group substituted by a halogenated alkyl group such as a trifluoromethylphenyl group, methylaminophenyl group, ethylaminophenyl group, cyclohexylaminophenyl group, N, N-dimethylaminophenyl Group, N, N-diethylaminophenyl group, N-phenyl-N-methylaminophenyl group, N-
Tolyl-N-methylaminophenyl group, N-chlorophenyl-N-ethylphenylaminophenyl group, N, N-
N-mono-substituted amino-substituted aryl group such as ditolylaminophenyl group or N, N-di-substituted amino-substituted aryl group, alkylthioaryl group or arylthioaryl group such as methylthiophenyl group, ethylthiophenyl group, phenylthiophenyl group And the like.

Specific examples of the substituted or unsubstituted aryloxy group include phenoxy, naphthoxy, anthranyloxy, 2-methylphenoxy, 3-methylphenoxy, 4-methylphenoxy, 2,3 -Dimethylphenoxy group, 2,4-dimethylphenoxy group,
2,5-dimethylphenoxy group, 2,6-dimethylphenoxy group, 3,4-dimethylphenoxy group, 3,5-dimethylphenoxy group, 3,6-dimethylphenoxy group,
2,3,4-trimethylphenoxy group, 2-ethylphenoxy group, 4-propylphenoxy group, 2-methyl-1
-Naphthoxy group, 3-methyl-1-naphthoxy group, 5-
Methyl-1-naphthoxy group, 8-methyl-1-naphthoxy group, 1-methyl-2-naphthoxy group, 3-methyl-2
-Naphthoxy group, 5-methyl-2-naphthoxy group, 8-
A straight chain having 1 to 10 carbon atoms such as a methyl-2-naphthoxy group,
An aryloxy group substituted with a branched or cyclic alkyl group, a 3-methoxyphenoxy group, a 2,3-dimethoxyphenoxy group, a 2,3,4-trimethoxyphenoxy group,
2-ethoxyphenoxy group, 4-propoxyphenoxy group, 2-methoxy-1-naphthoxy group, 4-methoxy-
1-naphthoxy group, 5-methoxy-1-naphthoxy group,
1-methoxy-2-naphthoxy group, 6-methoxy-2-
Aryloxy, fluorophenoxy, difluorophenoxy, trifluorophenoxy, chlorophenoxy, dichlorophenoxy, trichlorophenoxy, and aryloxy groups substituted with a linear, branched or cyclic C1-C10 alkoxy group such as a naphthoxy group , Bromophenoxy group, dibromophenoxy group, aryloxy group substituted by halogen atom such as iodophenoxy group, aryloxy group substituted by halogenated alkyl group such as trifluoromethylphenoxy group, methylaminophenoxy group, ethylaminophenoxy group , Cyclohexylaminophenoxy group, N, N-dimethylaminophenoxy group, N, N-
N such as diethylaminophenoxy, N-phenyl-N-methylaminophenoxy, N-tolyl-N-methylaminophenoxy, N-chlorophenyl-N-ethylphenylaminophenoxy, N, N-ditolylaminophenoxy, etc. An alkylthioaryloxy group such as a monosubstituted amino-substituted aryloxy group or an N, N-disubstituted amino-substituted aryloxy group, a methylthiophenoxy group, an ethylthiophenoxy group, a phenylthiophenoxy group, or an arylthioaryloxy group; .

Specific examples of the substituted or unsubstituted arylthio groups include phenylthio, naphthylthio, anthranylthio, 2-methylphenylthio, 3-methylphenylthio, 4-methylphenylthio, and 2-methylphenylthio. ,
3-dimethylphenylthio group, 2,4-dimethylphenylthio group, 2,5-dimethylphenylthio group, 2,6-
Dimethylphenylthio group, 3,4-dimethylphenylthio group, 3,5-dimethylphenylthio group, 3,6-dimethylphenylthio group, 2,3,4-trimethylphenylthio group, 2-ethylphenylthio group, 4-propylphenylthio group, 2-methyl-1-naphthylthio group, 3-methyl-1-naphthylthio group, 5-methyl-1-naphthylthio group, 8-methyl-1-naphthylthio group, 1-methyl-2-naphthylthio Group, 3-methyl-2-naphthylthio group, 5-methyl-2-naphthylthio group, 8-methyl-2
An arylthio group substituted with a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms such as a naphthylthio group, 3-methoxyphenylthio group, 2,3-dimethoxyphenylthio group, 2,3,4-trimethoxy Phenylthio group, 2-
Ethoxyphenylthio, 4-propoxyphenylthio, 2-methoxy-1-naphthylthio, 4-methoxy-1-naphthylthio, 5-methoxy-1-naphthylthio, 1-methoxy-2-naphthylthio, 6- A straight-chain, branched or cyclic C1-C10 arylthio group such as a methoxy-2-naphthylthio group or the like; an arylthio group substituted by a halogenated alkyl group such as a trifluoromethylphenylthio group; methylaminophenyl Thio, ethylaminophenylthio, cyclohexylaminophenylthio, N, N-dimethylaminophenylthio, N, N-diethylaminophenylthio, N-phenyl-N-methylaminophenylthio,
N-mono-substituted amino-substituted arylthio groups such as N-tolyl-N-methylaminophenylthio group, N-chlorophenyl-N-ethylphenylaminophenylthio group, N, N-ditolylaminophenylthio group or N, N- Examples thereof include an alkylthioarylthio group such as a disubstituted amino-substituted arylthio group, a methylthiophenylthio group, an ethylthiophenylthio group, and a phenylthiophenylthio group, and an arylthioarylthio group.

Specific examples of the substituted or unsubstituted heterocyclic group include a thionyl group, a furyl group, a pyrrolyl group, an imidazolyl group, a pyrazolyl group, a pyridyl group, a pyrazinyl group,
Pyrimidinyl group, pyridazinyl group, indolyl group, quinolyl group, isoquinolyl group, phthalazinyl group, quinoxalinyl group, quinazolinyl group, carbazolyl group, acridinyl group, phenazinyl group, furfuryl group, isothiazolinyl group, isoxazolyl group, furazanyl group, phenaxazinyl group, benzothiazolyl group , A benzoxazolyl group,
Examples include a benzimidazolyl group, a 2-methylpyridyl group, and a 3-cyanopyridyl group.

Specific examples of a substituted or unsubstituted aromatic ring formed by bonding adjacent substituents to each other include R ₁
And R ₂ , R ₂ and R ₃ , R ₃ and R ₄ , R ₅ and R ₆ , R ₆ and R ₇ , R ₇
And R ₈ , R ₉ and R ₁₀ , R ₁₀ and R ₁₁ , R ₁₄ and R ₁₅ or R ₁₅
A benzene ring or a naphthalene ring or the like attached to the position of R ₁₆ can be mentioned as. Specific examples of a substituted or unsubstituted heterocyclic ring formed by bonding adjacent substituents to each other include:
R ₉ and R _10, R ₁₀ and R _11, R ₁₄ and R ₁₅ or R ₁₅ and R ₁₆
A pyridine ring, a 2-methylpyridine ring, an oxazole ring, or the like, which is bonded to the position.

A method for manufacturing an electroluminescent device is disclosed in JP-A-58-194393; App.
l. Phys. Lett. , 51 (12), 913 (1
987); Appl. Phys. , 65 (9) 36
10 (1989); Japan Journal of
Applied Physics 27 (2) 268
(1988), 27 (4) 713 (1988); Miyata et al., “Organic EL Device Development Strategy” (Science Forum,
1992) can be used.

More specifically, as shown in FIG. 1, the electroluminescent element comprises an anode 4 on a glass substrate (ITO glass substrate) 5, a hole transport layer 3 made of an organic compound,
It has a structure in which the light emitting layer 2 containing the compound of the present invention and the metal cathode 1 are sequentially laminated. Further, as shown in FIG. 2, on a glass substrate (ITO glass substrate) 5, an anode 4, a hole transport layer made of an organic compound, a light emitting layer 2 containing the compound of the present invention, an electron transport layer 6, and a metal cathode 1 are arranged in this order. It may have a laminated structure. The compound of the present invention used for the light emitting layer 2 in the above device structure may be used alone or in combination of two or more.

Further, the hole transport layer 3 in the above element structure
The hole transporting compound that can be used for is a compound containing a tertiary amine that binds at least one aromatic ring, or another low molecular weight compound or polymer having a hole transporting property, preferably General formula (4) (Chemical formula 6) or (5)
A triphenylamine derivative, a pyrazoline derivative, polyvinyl carbazole, or polysilane represented by the following formula (7). Upon its use, a single compound or a mixture of two or more compounds may be used.

[0031]

Embedded image Wherein a, b, c, d, e, f, g, h and k are
Each independently represents an integer of 0, 1, 2, or 3. However,
a does not become 0. ]

[0032]

Embedded image [In the formula (5), l, m, n, p, q, r, s, t, u,
v, w, x, y, z, α and β each independently represent 0 or 1, and A represents two hydrogen atoms, —CH ₂ — and —C (CH ₃ )
Represents _2- . ]

The hole transporting layer, the light emitting layer, the electron transporting layer, the cathode and the anode can be manufactured by a generally known thin film forming method such as vapor deposition, sputtering and coating.

In manufacturing the electroluminescent device of the present invention, the thickness of the hole transport layer and the electron transport layer used must be at least such that no pinholes are generated. Increases, and a high driving voltage is required, which is not preferable. Therefore,
The thickness of the hole transport layer and the electron transport layer is usually from 1 nm to
It is 1000 nm, preferably 5 nm to 200 nm.

In producing the electroluminescent device of the present invention, the thickness of the light emitting layer used is increased by increasing the amount of the compound represented by the general formula (1) so that the luminance is increased and pinholes are not generated. However, when the thickness is too large, the resistance of the element increases, and a high driving voltage is required. Therefore, the thickness is usually 1 nm to 1000 nm, preferably 3 nm to 300 nm. The range of 5 nm to 200 nm is preferably used to increase the current density and the luminous efficiency.

The anode material used in the electroluminescent device of the present invention preferably has a work function as large as possible. For example, nickel, gold, platinum, palladium, selenium, iridium and alloys thereof, tin oxide, ITO, Copper iodide is preferred. Conductive polymers such as polyphenylene sulfide or polyaniline can also be used.

On the other hand, as the cathode material, those having a small work function, such as silver, lead, tin, magnesium, aluminum,
Calcium, indium, chromium, lithium or alloys thereof are used. One of the materials used as the anode or the cathode preferably has a transmittance of 50% or more in the oscillation wavelength region of the device. As the transparent electrode substrate used in the present invention, a glass or plastic film is used.

[0038]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. Example 1 (Synthesis Example-1) 20 g of indigo was added to 80 g of phenylacetic acid chloride, and the mixture was heated under reflux for 30 minutes. Thereafter, the mixture was once cooled, 300 g of nitrobenzene was added, the mixture was heated again, and hot filtration was performed at 200 ° C. After the filtrate was cooled and sufficiently crystallized, it was filtered and washed with water. After drying, 20 g of a compound of the following formula (A) was obtained.

[0039]

Embedded image

(Example of EL element production-1) N, N'-diphenyl-N, N'-ditolyl-
1,1-diphenyl-4,4-diamine was added to 5 × 10 ⁻⁵ t
Under a vacuum of orr, 50 nm is laminated by a resistance heating method. Next, the compound of the above formula (A) is laminated to a thickness of 50 nm,
Further, an aluminum electrode was deposited to a thickness of 150 nm under a vacuum of 6 × 10 ⁻⁵ torr. Plus on the ITO side of this element,
A negative electric field was applied to the aluminum side, and light emission from the glass substrate side of the device was observed. At a voltage of 19 V and a current density of 26 mA / cm ² , the brightness was 615 c
It emitted green light of d / m ² .

Example 2 (Synthesis Example 2) 20 g of indigo was added to 90 g of 4-tert-butylphenylacetic acid chloride, and 1 g of the mixture was refluxed.
Heated for hours. After that, cool once and use nitrobenzene 30
0 g was added, the mixture was heated again, and hot filtration was performed at 200 ° C.
After the filtrate was cooled and sufficiently crystallized, it was filtered, washed with water and dried to obtain 22 g of a red compound. Subsequently, 15 g of this compound was dissolved in 300 g of ethanol,
Cool. Here, hydrogen sulfide gas and hydrogen chloride gas were blown for 2 hours, and then only hydrogen sulfide gas was blown for 20 hours. Thereafter, the solvent was distilled off, and the residue was recrystallized from ethanol to obtain 6 g of a compound of the following formula (B).

[0042]

Embedded image

(Example 2 of manufacturing EL element) ITO glass substrate
On top of 1,1-bis (4-N, N-di-p-tolylamido
Nophenyl) cyclohexane is 5 × 10^-Fivetrue of torr
Under air, 50 nm is laminated by a resistance heating method. Then
The compound of the above formula (B) is laminated to a thickness of 50 nm, and then,
50 'of 2', 6,6'-tetramethyldiphenoquinone
m. 6 x 1 aluminum electrode
0^-FiveThe film was deposited under a torr vacuum of 150 nm. This element
Positive electric field on the ITO side and negative electric field on the aluminum side
And observe the light emission from the glass substrate side of the device.
Was. Voltage 19V, current density 26mA / cm ^TwoAt
Is stable and has a luminance of 525 cd / m^TwoThe red emission of
Was.

Example 3 (Synthesis example-3) 20 g of indigo was added to 120 g of 2-naphthylacetic acid chloride, and the mixture was heated under reflux for 1 hour.
Thereafter, the mixture was once cooled, 350 g of nitrobenzene was added, the mixture was heated again, and hot filtration was performed at 200 ° C. After the filtrate was cooled and sufficiently crystallized, it was filtered, washed with water and dried to obtain 25 g of a red compound. Subsequently, 20 g of this compound is dissolved in 300 g of pyridine and the temperature is raised to 75 ° C. 9.4 g of malononitrile was added thereto and reacted at the same temperature for 6 hours. After cooling, the precipitated crystals were filtered, washed with water and dried to obtain 16 g of a compound of the following formula (C).

[0045]

Embedded image

(EL Element Production Example-3) An EL element was produced in the same manner as in Example 1, except that the compound of the above formula (C) was used instead of the compound of the formula (A). At a voltage of 19 V and a current density of 26 mA / cm ² , the luminance was 60
It emitted red light of 0 cd / m ² .

Example 4 (Synthesis Example-4) 25 g of 2,6-bis (3,5,5-trimethylhexyloxy) indigo was added to 90 g of 4-tolylacetic acid chloride, and the mixture was heated under reflux for 30 minutes. Thereafter, the mixture was once cooled, 300 g of nitrobenzene was added, the mixture was heated again, and hot filtration was performed at 200 ° C. After the filtrate was cooled and sufficiently crystallized, it was filtered and washed with water. After drying, 20 g of a compound of the following formula (D) was obtained.

[0048]

Embedded image

(EL Element Production Example-4) An EL element was produced in the same manner as in Example 2 except that the compound of the above formula (D) was used instead of the compound of the formula (B). At a voltage of 19 V and a current density of 26 mA / cm ² , the luminance was 60
It emitted green light of 0 cd / m ² .

Comparative Example An EL device obtained by laminating a compound represented by the following formula instead of the compound (A) of Example 1 emitted green light of 80 cd / m ² .

[0051]

Embedded image

[0052]

According to the present invention, it has become possible to produce an electroluminescent device using an indigo derivative, which has high luminance and maintains good light-emitting performance for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an organic EL device in which an anode, a hole transport layer, a light emitting layer, and a cathode are sequentially stacked on a glass substrate.

FIG. 2 illustrates an organic EL device in which an anode, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode are sequentially stacked on a glass substrate.
It is sectional drawing which shows an example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal electrode 2 light emitting layer 3 hole transport layer 4 anode 5 glass substrate (ITO glass substrate) 6 electron transport layer

Claims (1)

[Claims] (1) The following general formula (1):[Wherein, R₁~ R₁₈Are each independently a hydrogen atom, a halo
Gen atom, hydroxyl group, mercapto group, cyano group, amino
Group, nitro group, substituted or unsubstituted alkyl group, substituted
Or an unsubstituted alkoxy group, a substituted or unsubstituted
Alkylthio group, substituted or unsubstituted N-monoalkyl
Ruamino group, substituted or unsubstituted N, N-dialkyl
Amino group, substituted or unsubstituted aryl group,
Or unsubstituted aryloxy group, substituted or unsubstituted
An arylthio group or a substituted or unsubstituted heterocyclic group
Show. Provided, however, that adjacent substituents
Substituted or unsubstituted aromatic ring or substituted or unsubstituted
May be formed. Z ₁And Z_TwoRespectively
Independently oxygen, sulfur or dicyanomethylene
Is shown. Indigo derivative represented by the formula
An electroluminescent device, comprising: