JP2013179198A - Material for organic electroluminescent element and application thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element which exhibits excellent characteristics.SOLUTION: A material for an organic EL element comprises a compound represented by the following general formula [1].

Description

  The present invention relates to a novel material for an organic electroluminescence device. More specifically, when used for an organic electroluminescence device (hereinafter abbreviated as an organic EL device), it can be formed by vapor deposition or spin coating, and has excellent performance (high glass transition temperature, high luminous efficiency, low voltage driving). In particular, the present invention relates to a material for an organic EL element that exhibits a high color purity and a long lifetime, and can be suitably used particularly for a green light emitting material.

  In recent years, organic EL elements have been required to have a long lifetime. There are various factors that can affect the lifetime of the device. One of the factors is considered to be that the glass transition temperature (Tg) of the material constituting the device has a significant effect on the lifetime of the device. . That is, it is pointed out that when the temperature of the element exceeds the Tg of the constituent material due to the use environment of the element or the heat generated during driving, the constituent material is crystallized and a non-light emitting region called a dark spot is generated. ing. For this reason, materials having higher Tg have been demanded (Non-Patent Documents 1 and 2).

  There are a large number of green light emitting materials that provide elements with excellent durability. As an example, green light-emitting elements using various anthracene compounds (Patent Documents 1 to 5) have been reported, but all have low solubility in general-purpose organic solvents and are practical for coating-type EL elements. There was a drawback that it was difficult to use the material.

Japanese Patent No. 2686418 Japanese Patent No. 2924809 Japanese Patent No. 2924810 Japanese Patent Application Laid-Open No. 10-072581 JP-A-10-265773

Toshito Shizushi, Chida Adachi, Hideyuki Murata, Organic EL Display, Ohmsha, 2004, pp. 139-143 Edited by Technical Information Association, the latest collection of latest functional pigments, Technical Information Association, 2007, pages 103-119

  An object of the present invention is to provide a compound that is useful as a material for an organic EL device and is soluble in a general-purpose organic solvent, and particularly provides a compound that can be suitably used as an organic EL device that emits green light. There is to do. Furthermore, it is to provide an organic EL element exhibiting excellent characteristics such as high luminous efficiency, low voltage driving, color purity, long life, heat resistance, and the like by using the material for the organic EL element.

  As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention.

  That is, the present invention relates to an organic EL device material comprising a compound represented by the following general formula [1].

General formula [1]

Wherein R ^{1 to} R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted Or an unsubstituted monovalent aliphatic heterocyclic group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a cyano group, a substituted silyl group, an alkoxyl group, an aryloxy group, a substituted amino group, or the following general group Represents a group represented by the formula [2], and R ^{1 to} R ⁴ , R ^{5 to} R ⁸ , R ^{9 to} R ¹³ , R ^{14 to} R ¹⁸ , R ^{19 to} R ²³ , and R ^{24 to} R ²⁸ are The adjacent groups may be bonded to each other to form a ring, provided that any one of R ^{19 to} R ²³ and any one of R ^{24 to} R ²⁸ are independent of each other. And a group represented by the following general formula [2].)

General formula [2]

(Wherein X ¹ represents a direct bond, a substituted or unsubstituted divalent aliphatic hydrocarbon group, an oxygen atom, or a sulfur atom;
R ^{29 to} R ³³ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted Represents a monovalent aliphatic heterocyclic group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a cyano group, a substituted silyl group, an alkoxyl group, an aryloxy group, or a substituted amino group, and R ^{29 to} R ^{In 33} , adjacent groups may be bonded to each other to form a ring. )

  Moreover, this invention relates to the said organic EL element material which consists of a compound represented by following General formula [3].

General formula [3]

Wherein R ^{35 to} R ⁷⁰ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted Or an unsubstituted monovalent aliphatic heterocyclic group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a cyano group, a substituted silyl group, an alkoxyl group, an aryloxy group, or a substituted amino group, R ^{35 to} R ³⁸ , R ^{39 to} R ⁴² , R ^{43 to} R ⁴⁷ , R ^{48 to} R ⁵² , R ^{55 to} R ⁵⁹ , and R ^{64 to} R ⁶⁸ are each a ring in which adjacent groups are bonded to each other. May be formed.
X ² and X ³ each independently represent a direct bond, a substituted or unsubstituted divalent aliphatic hydrocarbon group, an oxygen atom, or a sulfur atom. )

The present invention also relates to the above-mentioned organic EL device material, wherein X ² and X ³ are substituted or unsubstituted divalent aliphatic hydrocarbon groups, oxygen atoms, or sulfur atoms.

  Further, the present invention provides an organic EL element in which a plurality of organic layers including a light emitting layer are formed between a pair of electrodes, wherein at least one of the organic layers includes the organic EL element material. It relates to an element.

  Further, the present invention provides an organic EL element in which a light emitting layer or a plurality of organic layers including a light emitting layer is formed between a pair of electrodes, wherein the light emitting layer includes the organic EL element material. About.

  Moreover, this invention relates to the said organic EL element by which a light emitting layer is formed into a film by application | coating.

  Moreover, this invention relates to the ink composition for organic EL elements which consists of the said organic EL element material and an organic solvent.

  An organic EL device using the compound of the present invention as a material for an organic EL device can be suitably used as a flat panel display such as a wall-mounted television or a flat light emitter because it is driven at a low voltage and has a long lifetime. It can be applied to light sources such as copiers and printers, light sources such as liquid crystal displays and instruments, display boards, and indicator lights.

  Hereinafter, the present invention will be described in detail.

First, R ^{1 to} R ²⁸ in the general formula [1] are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic carbonization. Hydrogen group, substituted or unsubstituted monovalent aliphatic heterocyclic group, substituted or unsubstituted monovalent aromatic heterocyclic group, cyano group, substituted silyl group, alkoxyl group, aryloxy group, or substituted amino group Represents a group.

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

  In addition, the monovalent aliphatic hydrocarbon group refers to a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, and examples thereof include an alkyl group, an alkenyl group, an alkynyl group, and a cycloalkyl group. Can be mentioned.

  Here, as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, hexyl group, heptyl group, octyl group , An alkyl group having 1 to 18 carbon atoms such as a decyl group, a dodecyl group, a pentadecyl group, and an octadecyl group.

  Examples of the alkenyl group include vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-octenyl group, 1-decenyl group, 1 -C2-C18 alkenyl groups, such as an octadecenyl group, are mentioned.

  Examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-octynyl group, 1-decynyl group and 1-octadecynyl group. Examples include alkynyl groups having 2 to 18 carbon atoms.

  Examples of the cycloalkyl group include cycloalkyl groups having 3 to 18 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclooctadecyl group, and 2-indeno group. .

  Furthermore, examples of the monovalent aromatic hydrocarbon group include a monovalent monocyclic ring, a condensed ring, and a ring assembly aromatic hydrocarbon group.

  Here, examples of the monovalent monocyclic aromatic hydrocarbon group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 2,4-xylyl group, a p-cumenyl group, and a mesityl group. Examples thereof include monovalent monocyclic aromatic hydrocarbon groups having 6 to 18 carbon atoms.

  Examples of the monovalent condensed ring aromatic hydrocarbon group include 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 5-anthryl group, 1-phenanthryl group, 9-phenanthryl group, C1-C18 monovalent | monohydric condensed ring aromatic hydrocarbon groups, such as 1-acenaphthyl group, 2-azurenyl group, 1-pyrenyl group, 2-triphenylyl group, are mentioned.

  Examples of the monovalent ring-assembled aromatic hydrocarbon group include monovalent ring-assembled aromatic hydrocarbon groups having 12 to 18 carbon atoms such as o-biphenylyl group, m-biphenylyl group, and p-biphenylyl group. .

  Furthermore, examples of the monovalent aliphatic heterocyclic group include monovalent aliphatic heterocyclic groups having 3 to 18 carbon atoms such as a 2-pyrazolino group, a piperidino group, a morpholino group, and a 2-morpholinyl group.

  Furthermore, as the monovalent aromatic heterocyclic group, triazolyl group, 3-oxadiazolyl group, 2-furanyl group, 3-furanyl group, 2-furyl group, 3-furyl group, 2-thienyl group, 3-thienyl group 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-pyrazyl group, 2-oxazolyl group, 3-isoxazolyl Group, 2-thiazolyl group, 3-isothiazolyl group, 2-imidazolyl group, 3-pyrazolyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group Group, 8-quinolyl group, 1-isoquinolyl group, 2-quinoxalinyl group, 2-benzofuryl group, 2-benzothienyl group, N-indolyl group, N-carbazolyl group, N-acridinyl group, 2 Thiophenyl group, 3-thiophenyl group, bipyridyl group, and monovalent aromatic heterocyclic group having 2 to 18 carbon atoms such phenanthrolyl group.

  Moreover, as an alkoxyl group, C1-C8 alkoxyl groups, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a tert-butoxy group, an octyloxy group, a tert-octyloxy group, are mentioned.

  The aryloxy group includes aryloxy groups having 6 to 14 carbon atoms such as phenoxy group, 4-tert-butylphenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, and 9-anthryloxy group. Can be mentioned.

  The substituted amino group includes N-methylamino group, N-ethylamino group, N, N-diethylamino group, N, N-diisopropylamino group, N, N-dibutylamino group, N-benzylamino group, N , N-dibenzylamino group, N-phenylamino group, N-phenyl-N-methylamino group, N, N-diphenylamino group, N, N-bis (m-tolyl) amino group, N, N-bis (P-tolyl) amino group, N, N-bis (p-biphenylyl) amino group, bis [4- (4-methyl) biphenylyl] amino group, N-α-naphthyl-N-phenylamino group, N-β -Substituted amino groups having 2 to 26 carbon atoms such as naphthyl-N-phenylamino group.

In these R ^{1 to} R ²⁸ , a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, and a monovalent aromatic heterocyclic group, It may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, a monovalent aromatic heterocyclic group, A substituted silyl group may be mentioned.

Among these substituents, a halogen atom, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, and a monovalent aromatic heterocyclic group are R halogen atom in ¹ to R ^28, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, and is synonymous with monovalent aromatic heterocyclic group.

  The substituted silyl group is a substituted or unsubstituted alkyl group, or a silyl group substituted by a substituted or unsubstituted aryl group. A monoalkylsilyl group, a monoarylsilyl group, a dialkylsilyl group, a diarylsilyl group And substituted silyl groups such as a trialkylsilyl group and a triarylsilyl group.

  Here, as the monoalkylsilyl group, a monoalkylsilyl group such as a monomethylsilyl group, a monoethylsilyl group, a monobutylsilyl group, a monoisopropylsilyl group, a monodecanesilyl, a monoicosanesilyl group, or a monotriacontanesilyl group Is mentioned.

  Examples of the monoarylsilyl group include monoarylsilyl such as monophenylsilyl group, monotolylsilyl group, mononaphthylsilyl group, and monoanthrylsilyl group.

  Examples of the dialkylsilyl group include dialkylsilyl groups such as dimethylsilyl group, diethylsilyl group, dimethylethylsilyl group, diisopropylsilyl group, dibutylsilyl group, dioctylsilyl group, and didecanesilyl group.

  Examples of the diarylsilyl group include diarylsilyl such as diphenylsilyl group and ditolylsilyl group.

  Examples of the trialkylsilyl group include trialkylsilyl groups such as trimethylsilyl group, triethylsilyl group, dimethylethylsilyl group, triisopropylsilyl group, tributylsilyl group, and trioctylsilyl group.

  Examples of the triarylsilyl group include triarylsilyl groups such as a triphenylsilyl group and a tolylsilylsilyl group.

In addition, among R ^{1 to} R ^{28 in} the general formula [1], preferable examples include a hydrogen atom, a monovalent aliphatic hydrocarbon group, and a monovalent aromatic hydrocarbon group. , A hydrogen atom, and a monovalent aromatic hydrocarbon group, and particularly preferable examples include a hydrogen atom.

Next, R ^{29 to} R ³³ in the general formula [2] are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic. Hydrocarbon group, substituted or unsubstituted monovalent aliphatic heterocyclic group, substituted or unsubstituted monovalent aromatic heterocyclic group, cyano group, substituted silyl group, alkoxyl group, aryloxy group, or substituted Represents an amino group.

Here, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aliphatic heterocyclic group in R ^{29 to} R ³³ , Substituted or unsubstituted monovalent aromatic heterocyclic group, substituted silyl group, alkoxyl group, aryloxy group, and substituted amino group are substituted or unsubstituted in R ^{1 to} R ²⁸ in the general formula [1]. Substituted monovalent aliphatic hydrocarbon group, substituted or unsubstituted monovalent aromatic hydrocarbon group, substituted or unsubstituted monovalent aliphatic heterocyclic group, substituted or unsubstituted monovalent aromatic heterocyclic group It is synonymous with a cyclic group, a substituted silyl group, an alkoxyl group, an aryloxy group, and a substituted amino group.

Also, substituted silyl group in R ²⁹ to R ³³ are as defined substituted silyl group in the general formula [1] substituent that may be R ¹ to R ²⁸ has in.

  In the general formula [2], the monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, and monovalent aromatic heterocyclic group are further substituted with other substituents. Also good. Examples of such a substituent include a halogen atom, a cyano group, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, a monovalent aromatic heterocyclic group, A substituted silyl group may be mentioned. The above-mentioned thing is mentioned as an example of these substituents.

  Further, among the general formula [2], preferable examples include a hydrogen atom, a monovalent aliphatic hydrocarbon group, and a monovalent aromatic hydrocarbon group, and more preferable examples include a monovalent aliphatic group. A hydrocarbon group is mentioned.

Next, R ^{35 to} R ⁷⁰ in the general formula [3] are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic. Hydrocarbon group, substituted or unsubstituted monovalent aliphatic heterocyclic group, substituted or unsubstituted monovalent aromatic heterocyclic group, cyano group, substituted silyl group, alkoxyl group, aryloxy group, or substituted Represents an amino group.

Here, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aliphatic heterocyclic group in R ^{35 to} R ⁷⁰ , Substituted or unsubstituted monovalent aromatic heterocyclic group, substituted silyl group, alkoxyl group, aryloxy group, and substituted amino group are substituted or unsubstituted in R ^{1 to} R ²⁸ in the general formula [1]. Substituted monovalent aliphatic hydrocarbon group, substituted or unsubstituted monovalent aromatic hydrocarbon group, substituted or unsubstituted monovalent aliphatic heterocyclic group, substituted or unsubstituted monovalent aromatic heterocyclic group It is synonymous with a cyclic group, a substituted silyl group, an alkoxyl group, an aryloxy group, and a substituted amino group.

Also, substituted silyl group in R ³⁵ to R ⁷⁰ are as defined substituted silyl group in the general formula [1] substituent that may be R ¹ to R ²⁸ has in.

  In the general formula [3], the monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, and monovalent aromatic heterocyclic group are further substituted with other substituents. Also good. Examples of such a substituent include a halogen atom, a cyano group, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, a monovalent aromatic heterocyclic group, A substituted silyl group may be mentioned. The above-mentioned thing is mentioned as an example of these substituents.

  In addition, among the general formula [3], preferable examples include a hydrogen atom, a monovalent aliphatic hydrocarbon group, and a monovalent aromatic hydrocarbon group, and more preferable examples include a monovalent aliphatic group. A hydrocarbon group is mentioned.

  Representative examples of the compound represented by the general formula [1] used in the present invention are shown in the following Table 1, but the present invention is not limited to these representative examples.

  High-purity materials are required for materials for organic EL devices, but the compounds of the present invention can be obtained by sublimation purification method, recrystallization method, reprecipitation method, zone melting method, column purification method, adsorption method, etc. A combination of methods can be performed. Of these purification methods, the recrystallization method is preferred. For compounds having sublimation properties, it is preferable to employ a sublimation purification method. In the sublimation purification, it is preferable to employ a method in which the sublimation boat is maintained at a temperature lower than the temperature at which the target compound sublimates, and the sublimation impurities are removed in advance. In addition, it is desirable to apply a temperature gradient to the portion where the sublimate is collected so that the sublimate is dispersed in the impurities and the target product. Sublimation purification as described above is purification that separates impurities, and can be applied to the present invention. In addition, sublimation purification is useful for predicting the difficulty of the material vapor deposition.

  Next, the ink composition for organic EL elements will be described.

  The ink composition for organic EL elements in the present invention contains at least the material for organic EL elements of the present invention and a solvent.

  Various solvents are applicable as the solvent contained in the above-mentioned ink composition for organic EL elements, and are not particularly limited. For example, aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene and tetralin; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene and anisole , Phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole and other aromatic ethers; phenyl acetate, phenyl propionate, methyl benzoate, benzoic acid Aromatic esters such as ethyl, propyl benzoate and n-butyl benzoate; ketones having an alicyclic ring such as cyclohexanone and cyclooctanone; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; methyl ethyl ketone and cyclohexano Alcohol having an alicyclic ring such as ruthenium or cyclooctanol; Aliphatic alcohol such as butanol or hexanol; Aliphatic ether such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether or propylene glycol-1-monomethyl ether acetate (PGMEA); Ethyl acetate And aliphatic esters such as n-butyl acetate, ethyl lactate and n-butyl lactate.

  Of these, aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene, tetralin and the like are preferable in that they have low water solubility and are not easily altered.

  These solvents may be used alone or in combination. In addition, the solvent which can be used is not limited to these.

  Since organic electroluminescent devices use many materials such as cathodes that deteriorate significantly due to moisture, the presence of moisture in the composition causes moisture to remain in the dried film, degrading the device characteristics. The possibility is considered and it is not preferable.

  Further, in order to reduce a decrease in film formation stability due to solvent evaporation from the composition during wet film formation, the boiling point is 100 ° C. or higher, preferably 150 ° C. as the solvent of the composition for organic EL elements. As described above, it is more effective to use a solvent having a boiling point of 200 ° C. or higher.

  The ink composition for an organic EL element of the present invention is preferably used for an organic EL light emitting element in which a light emitting material is a low molecular material and a layer containing the light emitting material is formed by a wet film forming method.

  The ink composition for organic EL elements of the present invention is mainly used for containing a light emitting material and forming a light emitting layer, but may be used for other layers such as a hole transport layer.

  In the present invention, as long as the object of the present invention is not impaired, the ink composition of the present invention may optionally contain other known light-emitting materials in the light emitting layer. A light-emitting layer containing another known light-emitting material may be stacked on the light-emitting layer formed by a wet film formation method. In this case, the light emitting layer containing another known light emitting material may be formed by a dry method such as a vacuum evaporation method.

  In the organic EL element ink composition of the present invention, the content of the organic EL element material of the present invention is preferably 0.5 wt% or more. Usually, the thickness of the light-emitting layer of the organic EL element is 10 to 100 nm, but generally it is often 50 nm or more. When the film thickness is less than 50 nm, problems such as a decrease in light emission performance and a large color tone deviation occur. In order to easily form a film thickness of 50 nm or more, the solution concentration is preferably 0.5 wt% or more. When the concentration is lower than 0.5 wt%, it is difficult to form a thick film.

  In addition to the organic EL element material and solvent described above, a known additive may be added to the ink composition for an organic EL element of the present invention as necessary.

  The ink composition for an organic EL device of the present invention is a known wet film forming method, for example, a coating method, an inkjet method, a dip coating method, a die coating method, a spray coating method, a spin coating method, a roll coater method, a dipping coating method. The film can be formed by a screen printing method, a flexographic printing method, a screen printing method, an LB method, or the like.

  Here, the organic EL element which can be produced using the organic electroluminescent element material comprising the compound of the present invention will be described in detail.

  The organic EL element is composed of an element in which a single layer or a multilayer organic layer is formed between an anode and a cathode. Here, the single layer type organic EL element is an element composed of only a light emitting layer between an anode and a cathode. Point to. On the other hand, the multilayer organic EL element facilitates injection of holes and electrons into the light emitting layer in addition to the light emitting layer, and facilitates recombination of holes and electrons in the light emitting layer. For the purpose of this, it refers to a layer in which a hole injection layer, a hole transport layer, a hole blocking layer, an electron injection layer, and the like are laminated. Further, an interlayer that is adjacent to the light emitting layer between the light emitting layer and the anode and has a role of separating the light emitting layer and the anode or the light emitting layer from the hole injection layer or the hole transport layer. Layers may be inserted. Therefore, typical element configurations of the multilayer organic EL element include (1) anode / hole injection layer / light emitting layer / cathode, and (2) anode / hole injection layer / hole transport layer / light emitting layer / cathode. (3) Anode / hole injection layer / light emitting layer / electron injection layer / cathode, (4) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode, (5) Anode / positive Hole injection layer / light emitting layer / hole blocking layer / electron injection layer / cathode, (6) anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron injection layer / cathode, (7) Anode / light emitting layer / hole blocking layer / electron injection layer / cathode, (8) anode / light emitting layer / electron injection layer / cathode (9) anode / hole injection layer / hole transport layer / interlayer layer / light emitting layer / Cathode, (10) anode / hole injection layer / interlayer layer / light emitting layer / electron injection layer / cathode, (11) anode / hole injection layer / hole transport layer / inter layer Layer / light emitting layer / electron injection layer / cathode, an element formed by laminating a multilayer structure etc. can be considered.

  Moreover, each organic layer mentioned above may be formed by the layer structure of two or more layers, respectively, and several layers may be laminated | stacked repeatedly. As such an example, an element configuration called “multi-photon emission” in which a part of the above-described multilayer organic EL element is multilayered has been proposed in recent years for the purpose of improving light extraction efficiency. For example, in an organic EL device composed of a glass substrate / anode / hole transport layer / electron transporting light emitting layer / electron injection layer / charge generating layer / light emitting unit / cathode, the charge generating layer and the light emitting unit There is a method of laminating a plurality of portions.

  The organic EL device material of the present invention may be used for any of the above-mentioned layers, but can be suitably used as a light emitting layer material particularly when a green light emitting device is produced. The organic EL device material of the present invention can be used not only as a single compound but also as a combination of two or more compounds, that is, mixed, co-evaporated, laminated, etc. is there. Furthermore, in the light emitting layer mentioned above, you may use with another material.

For the hole injection layer, a hole injection material that exhibits an excellent hole injection effect with respect to the light emitting layer and that can form a hole injection layer excellent in adhesion to the anode interface and thin film formability is used. In addition, when such materials are laminated in multiple layers and a material having a high hole injection effect and a material having a high hole transport effect are laminated, the materials used for each are called a hole injection material and a hole transport material. Sometimes. The organic EL device material of the present invention can be suitably used for both hole injection materials and hole transport materials. These hole injection materials and hole transport materials need to have a high hole mobility and a small ionization energy of usually 5.5 eV or less. Such a hole injection layer is preferably a material that transports holes to the light emitting layer with a lower electric field strength, and further has a hole mobility of at least when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. What is 10 ^<-6 > cm ^{< 2} > / V * second is preferable. Other hole injection materials and hole transport materials that can be used by mixing with the organic EL device material of the present invention are not particularly limited as long as they have the above-mentioned preferable properties. Any material can be selected and used from those commonly used as charge transport materials for holes in a conductive material and known materials used for hole injection layers of organic EL devices.

  Specific examples of such hole injection materials and hole transport materials include triazole derivatives (see US Pat. No. 3,112,197) and oxadiazole derivatives (US Pat. No. 3,189,447). Imidazole derivatives (see Japanese Patent Publication No. 37-16096), polyarylalkane derivatives (US Pat. Nos. 3,615,402, 3,820,989, 3,542,544, JP-B-45-555, JP-A-51-10983, JP-A-51-93224, JP-A-55-17105, JP-A-56-4148, JP-A-55- No. 108667, No. 55-156953, No. 56-36656, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. No. 3,180, No. 29, No. 4,278,746, JP-A 55-88064, No. 55-88065, No. 49-105537, No. 55-51086, No. 56-80051. No. 56-88141, No. 57-45545, No. 54-112437, No. 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404, Japanese Patent Publication Nos. 51-10105, 46-3712, 47-25336, JP 54-53435, 54-110536, 54-1119925, etc.), arylamine Derivatives (US Pat. Nos. 3,567,450, 3,180,703, 3,240,597, 3 No. 658,520, No. 4,232,103, No. 4,175,961, No. 4,012,376, JP-B 49-35702, No. 39 -27577, JP-A-55-144250, JP-A-56-119132, JP-A-56-22437, West German Patent No. 1,110,518, etc.), amino-substituted chalcone derivatives (US patents) No. 3,526,501), oxazole derivatives (disclosed in US Pat. No. 3,257,203, etc.), styryl anthracene derivatives (see JP 56-46234 A, etc.), Fluorenone derivatives (see JP-A-54-110837, etc.), hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54-59143, 55-52063, 55-52064, 55-46760, 55-85495, 57-11350, 57-148749, JP-A-2-311591, etc. Stilbene derivatives (Japanese Patent Laid-Open Nos. 61-210363, 61-228451, 61-14642, 61-72255, 62-47646, 62-36674) 62-10652, 62-30255, 60-93455, 60-94462, 60-174749, 60-175052, etc.), silazane derivatives (US) Patent No. 4,950,950), polysilane (JP-A-2-204996), aniline copolymer (JP-A-2-282263), an electroconductive oligomer (particularly a thiophene oligomer) disclosed in JP-A-1-211399 and the like.

  As the hole injecting material and the hole transporting material, those described above can be used. Porphyrin compounds (Japanese Patent Laid-Open No. 63-295965), aromatic tertiary amine compounds and styrylamine compounds (US Pat. No. 4,127,412, JP-A-53-27033, 54-58445, 54-149634, 54-64299, 55-79450, 55-144250 No. 56-119132, No. 61-295558, No. 61-98353, No. 63-295695, etc.) can also be used. For example, 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl having two condensed aromatic rings in the molecule described in US Pat. No. 5,061,569, etc. And 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) -N-phenyl, in which three triphenylamine units described in JP-A-4-308688 are linked in a starburst type. Amino) triphenylamine, etc. In addition, examples of the hole injection material include phthalocyanine derivatives such as copper phthalocyanine and hydrogen phthalocyanine, and other aromatic dimethylidene compounds, p-type Si, p-type SiC, etc. These inorganic compounds can also be used as hole injection materials and hole transport materials.

Further, materials that can be used for the hole injection layer include molybdenum oxide (MnO _x ), vanadium oxide (VO _x ), ruthenium oxide (RuO _x ), copper oxide (CuO _x ), tungsten oxide (WO _x ), and iridium oxide. Inorganic oxides such as (IrO _x ) are also included.

  Specific examples of the aromatic tertiary amine derivative include, for example, 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-phenyl-cyclohexane, N, N'-bis (4 '-Diphenylamino-4-biphenylyl) -N, N'-diphenyl Nzine, N, N′-bis (4′-diphenylamino-4-phenyl) -N, N′-diphenylbenzidine, N, N′-bis (4′-diphenylamino-4-phenyl) -N, N ′ -Di (1-naphthyl) benzidine, N, N'-bis (4'-phenyl (1-naphthyl) amino-4-phenyl) -N, N'-diphenylbenzidine, N, N'-bis (4'- Phenyl (1-naphthyl) amino-4-phenyl) -N, N′-di (1-naphthyl) benzidine and the like can be mentioned, and these can be used for both hole injection materials and hole transport materials.

  Examples of the material used for the interlayer layer include polymers containing aromatic amines such as polyvinylcarbazole and derivatives thereof, polyarylene derivatives having aromatic amines in the side chain or main chain, arylamine derivatives, and triphenyldiamine derivatives. In addition, as a method for forming the interlayer layer, when a high molecular weight material is used, a method by film formation from a solution is exemplified.

  For the formation of an interlayer layer from a solution, a known wet film forming method, for example, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, Coating methods such as a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, an ink jet printing method, a capillary coating method, and a nozzle coating method can be used.

  The thickness of the interlayer layer varies depending on the material to be used, and may be selected so that the driving voltage and the light emission efficiency are appropriate values. Usually, the thickness is 1 nm to 1 μm, preferably 2 to 500 nm. More preferably, it is 5-200 nm.

  On the other hand, for the electron injection layer, an electron injection material that exhibits an excellent electron injection effect with respect to the light emitting layer and that can form an electron injection layer excellent in adhesion to the cathode interface and thin film formability is used. Examples of such electron injection materials include metal complex compounds, nitrogen-containing five-membered ring derivatives, fluorenone derivatives, anthraquinodimethane derivatives, diphenoquinone derivatives, thiopyrandioxide derivatives, perylenetetracarboxylic acid derivatives, fluorenylidenemethane. Derivatives, anthrone derivatives, silole derivatives, triarylphosphine oxide derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives, polyfluorene and its derivatives, calcium acetylacetonate, sodium acetate and the like. In addition, inorganic / organic composite materials doped with metal such as cesium in bathophenanthroline (Proceedings of the Society of Polymer Science, Vol. 50, No. 4, 660, published in 2001), and the 50th Applied Physics Related Lecture Lecture Proceedings, No. Examples of electron injection materials include BCP, TPP, T5MPyTZ, etc., published on page 3, 1402, 2003. However, a thin film necessary for device fabrication can be formed, electrons from the cathode can be injected, and electrons can be transported. If it is material, it will not specifically limit to these.

  Preferable examples of the electron injection material include metal complex compounds, nitrogen-containing five-membered ring derivatives, silole derivatives, and triarylphosphine oxide derivatives. As a preferable metal complex compound that can be used in the present invention, a metal complex of 8-hydroxyquinoline or a derivative thereof is suitable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include tris (8-hydroxyquinolinate) aluminum, tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (4-methyl-8- Hydroxyquinolinato) aluminum, tris (5-methyl-8-hydroxyquinolinato) aluminum, tris (5-phenyl-8-hydroxyquinolinato) aluminum, bis (8-hydroxyquinolinato) (1-naphtholate) ) Aluminum, bis (8-hydroxyquinolinate) (2-naphtholate) aluminum, bis (8-hydroxyquinolinate) (phenolate) aluminum, bis (8-hydroxyquinolinato) (4-cyano-1-naphtholate) ) Aluminum, bis (4-methyl-8) Hydroxyquinolinato) (1-naphtholato) aluminum, bis (5-methyl-8-hydroxyquinolinato) (2-naphtholato) aluminum, bis (5-phenyl-8-hydroxyquinolinato) (phenolate) aluminum, Bis (5-cyano-8-hydroxyquinolinate) (4-cyano-1-naphtholato) aluminum, bis (8-hydroxyquinolinato) chloroaluminum, bis (8-hydroxyquinolinato) (o-cresolate) Aluminum complex compounds such as aluminum, tris (8-hydroxyquinolinato) gallium, tris (2-methyl-8-hydroxyquinolinato) gallium, tris (4-methyl-8-hydroxyquinolinato) gallium, tris ( 5-Methyl-8-hydroxyquinolinate Gallium, tris (2-methyl-5-phenyl-8-hydroxyquinolinato) gallium, bis (2-methyl-8-hydroxyquinolinato) (1-naphtholato) gallium, bis (2-methyl-8-hydroxy) Quinolinate) (2-naphtholato) gallium, bis (2-methyl-8-hydroxyquinolinato) (phenolate) gallium, bis (2-methyl-8-hydroxyquinolinato) (4-cyano-1-naphtholate) ) Gallium, bis (2,4-dimethyl-8-hydroxyquinolinato) (1-naphtholate) gallium, bis (2,5-dimethyl-8-hydroxyquinolinato) (2-naphtholato) gallium, bis (2 -Methyl-5-phenyl-8-hydroxyquinolinate) (phenolate) gallium, bis (2-methyl-5- Cyano-8-hydroxyquinolinate) (4-cyano-1-naphtholate) gallium, bis (2-methyl-8-hydroxyquinolinate) chlorogallium, bis (2-methyl-8-hydroxyquinolinate) ( In addition to gallium complex compounds such as o-cresolate) gallium, 8-hydroxyquinolinate lithium, bis (8-hydroxyquinolinato) copper, bis (8-hydroxyquinolinato) manganese, bis (10-hydroxybenzo [h ] Quinolinato) metal complex compounds such as beryllium, bis (8-hydroxyquinolinato) zinc, bis (10-hydroxybenzo [h] quinolinato) zinc.

  Among the electron injection materials that can be used in the present invention, preferable nitrogen-containing five-membered ring derivatives include oxazole derivatives, thiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, and triazole derivatives. , 5-bis (1-phenyl) -1,3,4-oxazole, 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-butyl benzene], 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 can be mentioned.

The light emitting layer of the organic EL device of the present invention preferably has the following functions.
Injection function; function transport function that can inject holes from the anode or hole injection layer when an electric field is applied, and electrons from the cathode or electron injection layer; electric field of injected charges (electrons and holes) Light emitting function: A function that provides a field for recombination of electrons and holes and connects it to light emission. However, there is a difference between the ease of hole injection and the ease of electron injection. In addition, the transport ability represented by the mobility of holes and electrons may be large or small.

  The material for an organic electroluminescence element of the present invention can be suitably used as a light emitting layer. The organic electroluminescent device material of the present invention can be used as a host material or a dopant material in a light emitting layer and combined with other compounds to form a light emitting layer. Can be suitably used.

  Fluorescent brighteners such as benzothiazole-based, benzimidazole-based, and benzoxazole-based materials, metal chelated oxinoid compounds, and styrylbenzene-based materials in order to obtain green to green light emission using the organic electroluminescent device material of the present invention Compounds can be used. Specific examples of these compounds include compounds disclosed in, for example, JP-A-59-194393. Still other useful compounds are listed in Chemistry of Synthetic Soybean (1971) pages 628-637 and 640.

  As the metal chelated oxinoid compound, for example, compounds disclosed in JP-A-63-295695 can be used. As typical examples, 8-hydroxyquinoline metal complexes such as tris (8-quinolinol) aluminum, dilithium epinetridione and the like can be mentioned as suitable compounds.

  As the styrylbenzene compound, for example, those disclosed in European Patent No. 0319881 and European Patent No. 0373582 can be used. And the distyrylpyrazine derivative currently disclosed by Unexamined-Japanese-Patent No. 2-252793 can also be used as a material of a light emitting layer. In addition, polyphenyl compounds disclosed in EP 0387715 can also be used as a material for the light emitting layer.

  Further, in addition to the above-described fluorescent brightener, metal chelated oxinoid compound, styrylbenzene compound and the like, for example, 12-phthaloperinone (J. Appl. Phys., Vol. 27, L713 (1988)), 1,4- Diphenyl-1,3-butadiene, 1,1,4,4-tetraphenyl-1,3-butadiene (Appl. Phys. Lett., Vol. 56, L799 (1990)), naphthalimide derivatives No. 2-305886), perylene derivatives (Japanese Patent Laid-Open No. 2-189890), oxadiazole derivatives (Japanese Patent Laid-Open No. Hei 2-216791, or the 38th Applied Physics Related Conference) were disclosed by Hamada et al. Oxadiazole derivatives), aldazine derivatives (JP-A-2-220393), pyrazirine Conductor (JP-A-2-220394), cyclopentadiene derivative (JP-A-2-289675), pyrrolopyrrole derivative (JP-A-2-29691), styrylamine derivative (Appl. Phys. Lett., 56th) Vol. L799 (1990), coumarin compounds (Japanese Patent Laid-Open No. 2-191694), International Patent Publications WO 90/13148 and Appl. Phys. Lett., Vol 58, 18, P1982 (1991). Polymer compounds, 9,9 ′, 10,10′-tetraphenyl-2,2′-bianthracene, PPV (polyparaphenylene vinylene) derivatives, polyfluorene derivatives and copolymers thereof, for example, the following general formula [ 4] to those having the structure of the general formula [6].

General formula [4]

(In the formula, R ^x1 and R ^X2 each independently represent a monovalent aliphatic hydrocarbon group, and n1 represents an integer of 3 to 100.)

General formula [5]

(In the formula, R ^x3 and R ^X4 each independently represent a monovalent aliphatic hydrocarbon group, and n2 and n3 each independently represent an integer of 3 to 100.)

General formula [6]

(In the formula, R ^X5 and R ^X6 each independently represent a monovalent aliphatic hydrocarbon group, n4 and n5 each independently represent an integer of 3 to 100, and Ph represents a phenyl group.)

In addition, the general formula (Rs-Q) _2- Al-O-L3 (wherein L3 is a hydrocarbon having 6 to 24 carbon atoms including a phenyl moiety) described in JP-A-5-258862, etc. O-L3 is a phenolate ligand, Q represents a substituted 8-quinolinolato ligand, Rs sterically represents that two or more substituted 8-quinolinolato ligands are bonded to an aluminum atom. And a bis (2-methyl-8-quinolinolato) (para-phenylphenolato) aluminum (III) compound, which represents an 8-quinolinolato ring substituent selected to interfere. ), Bis (2-methyl-8-quinolinolato) (1-naphtholato) aluminum (III) and the like.

Although there is no restriction | limiting in particular as a light emitting layer in the case of obtaining white light emission, The following can be used. The energy level of each layer of the organic EL laminated structure is defined and light is emitted using tunnel injection (European Patent No. 0390551).
Similarly, a white light emitting element is described as an example of an element using tunnel injection (Japanese Patent Laid-Open No. 3-230584). A light-emitting layer having a two-layer structure is described (JP-A-2-220390 and JP-A-2-216790). A structure in which a light emitting layer is divided into a plurality of materials each having a different emission wavelength (Japanese Patent Laid-Open No. 4-51491). A structure in which a color light emitter (fluorescence peak 380 to 480 nm) and a green light emitter (480 to 580 nm) are laminated and a red phosphor is further contained (Japanese Patent Laid-Open No. 6-207170). A structure in which the color light emitting layer contains a color fluorescent dye, the green light emitting layer has a region containing a red fluorescent dye, and further contains a green phosphor (Japanese Patent Laid-Open No. 7-142169).

Furthermore, the material used for the anode of the organic EL device of the present invention is preferably a material having a work function (4 eV or more) metal, alloy, electrically conductive compound or a mixture thereof as an electrode substance. Specific examples of such an electrode substance include metals such as Au and conductive materials such as CuI, ITO, SnO ₂ and ZnO. In order to form this anode, a thin film can be formed from these electrode materials by a method such as vapor deposition or sputtering. The anode desirably has such a characteristic that when light emitted from the light emitting layer is extracted from the anode, the transmittance of the anode for light emission is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. Further, although the film thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

  The material used for the cathode of the organic EL device of the present invention is a material having a small work function (4 eV or less) metal, alloy, electrically conductive compound and a mixture thereof as an electrode substance. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / silver alloy, aluminum / aluminum oxide, aluminum / lithium alloy, indium, and rare earth metals. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. Here, when light emitted from the light-emitting layer is extracted from the cathode, the transmittance of the cathode for light emission is preferably greater than 10%. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

  Regarding the method for producing the organic EL device of the present invention, an anode, a light emitting layer, a hole injection layer as necessary, and an electron injection layer as necessary are formed by the above materials and methods, and finally a cathode is formed. do it. Moreover, an organic EL element can also be produced from the cathode to the anode in the reverse order.

  This organic EL element is manufactured on a translucent substrate. This translucent substrate is a substrate that supports the organic EL element, and for the translucency, it is desirable that the transmittance of light in the visible region of 400 to 700 nm is 50% or more, preferably 90% or more, Further, it is preferable to use a smooth substrate.

  These substrates have mechanical and thermal strengths and are not particularly limited as long as they are transparent. For example, glass plates, synthetic resin plates and the like are preferably used. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the synthetic resin plate include plates such as polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, and polysulfone resin.

  As a method for forming each layer of the organic EL element of the present invention, a dry film forming method such as vacuum deposition, electron beam irradiation, sputtering, plasma, ion plating, or a wet film forming method such as spin coating, dipping, or flow coating is used. Either method can be applied. In addition, Special Table 2002-53482, S.I. T.A. Lee, et al. , Proceedings of SID'02, p. LITI (Laser Induced Thermal Imaging) method described in 784 (2002), printing (offset printing, flexographic printing, gravure printing, screen printing), inkjet, and the like can also be applied.

  The organic layer is particularly preferably a molecular deposited film. Here, the molecular deposited film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidifying from a material compound in a solution state or a liquid phase state. Can be classified from a thin film (accumulated film) formed by the LB method according to a difference in an agglomerated structure and a higher-order structure and a functional difference resulting therefrom. Further, as disclosed in JP-A-57-51781, a binder such as a resin and a material compound are dissolved in a solvent to form a solution, which is then thinned by a spin coat method or the like. An organic layer can be formed. The film thickness of each layer is not particularly limited, but if the film thickness is too thick, a large applied voltage is required to obtain a constant light output, resulting in poor efficiency. Conversely, if the film thickness is too thin, pinholes, etc. And it becomes difficult to obtain sufficient light emission luminance even when an electric field is applied. Accordingly, the thickness of each layer is suitably in the range of 1 nm to 1 μm, but more preferably in the range of 10 nm to 0.2 μm.

  Further, in order to improve the stability of the organic EL element with respect to temperature, humidity, atmosphere and the like, a protective layer may be provided on the surface of the element, or the entire element may be covered or sealed with a resin or the like. In particular, when the entire element is covered or sealed, a photocurable resin that is cured by light is preferably used.

  The current applied to the organic EL element of the present invention is usually a direct current, but a pulse current or an alternating current may be used. The current value and the voltage value are not particularly limited as long as the element is within a range not destroying the element. However, considering the power consumption and life of the element, it is desirable to efficiently emit light with as little electrical energy as possible.

  The organic EL device driving method of the present invention can be driven not only by the passive matrix method but also by the active matrix method. Further, the method for extracting light from the organic EL device of the present invention is applicable not only to the method of bottom emission for extracting light from the anode side but also to the method of top emission for extracting light from the cathode side. These methods and techniques are described in Shinji Kido, “All about organic EL”, published by Nihon Jitsugyo Shuppansha (published in 2003).

  Examples of the main method of full colorization of the organic EL device of the present invention include a three-color coating method, a color conversion method, and a color filter method. In the three-color coating method, an evaporation method using a shadow mask, an ink jet method, and a printing method can be used. In addition, Special Table 2002-53482, S.I. T.A. Lee, et al. , Proceedings of SID'02, p. 784 (2002) can also be used. The laser thermal transfer method (also referred to as Laser Induced Thermal Imaging, LITI method) can also be used. In the color conversion method, a light emitting layer that emits color light is used to convert green and red, which have wavelengths longer than colors, through a color conversion (CCM) layer in which fluorescent dyes are dispersed. The color filter method uses a white light emitting organic EL element to extract light of three primary colors through a color filter for liquid crystal. In addition to these three primary colors, a part of white light is directly extracted and used for light emission. Thus, the luminous efficiency of the entire device can be increased.

  Furthermore, the organic EL element of the present invention may adopt a microcavity structure. This is because the organic EL element has a structure in which the light emitting layer is sandwiched between the anode and the cathode, and the emitted light causes multiple interference between the anode and the cathode, but the reflectance and transmission of the anode and the cathode. This is a technology that actively uses the multiple interference effect and controls the emission wavelength extracted from the device by appropriately selecting the optical characteristics such as the rate and the film thickness of the organic layer sandwiched between them. . Thereby, it is also possible to improve the emission chromaticity. For the mechanism of this multiple interference effect, see J.A. Yamada et al., AM-LCD Digest of Technical Papers, OD-2, p. 77-80 (2002).

  As described above, the organic EL element using the organic electroluminescence element material of the present invention can obtain color emission for a long time with a low driving voltage. Therefore, this organic EL device can be used as a flat panel display such as a wall-mounted television and various flat light emitters, as well as a light source such as a copying machine or a printer, a light source such as a liquid crystal display or an instrument, a display board, a marker lamp, etc. Can be applied.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples at all.

Example 1
Compound 1 Synthesis Method Compound 1 was synthesized using the following reaction formulas (1) to (3).

Reaction formula (1)

  Under a nitrogen atmosphere, 12.8 g (0.05 mol) of 9-bromo-anthracene, 16.05 g (0.05 mol) of bis (4-biphenyl) amine, 4.74 g of sodium tert-butoxide, 0.20 g of palladium acetate, Tris (Tert-Butyl) phosphine (0.91 g) and xylene (100 g) were added to a four-necked flask and heated to reflux for 5 hours. Thereafter, the reaction solution was extracted with toluene and water, and the organic layer was concentrated under reduced pressure. Thereafter, the residue was separated and purified by column chromatography with toluene and hexane to obtain 17.2 g (yield 69%) of Compound (I). The obtained product was purified by toluene recrystallization and sublimation.

Reaction formula (2)

Under a nitrogen atmosphere, 7.50 g (0.013 mol) of compound (I), 2.77 g (0.015 mol) of N-bromosuccinimide and 150 ml of tetrahydrofuran were added to a four-necked flask and stirred at room temperature for 5 hours. Thereafter, 200 g of water was added to the reaction solution to precipitate a yellow solid. Washing with water and methanol were performed by suction. Thereafter, the yellow solid was separated and purified by column chromatography with toluene and hexane to obtain 7.52 g (yield 88%) of compound (II).
Reaction formula (3)

  Under a nitrogen atmosphere, 2.88 g (0.005 mol) of compound (II), 0.84 g (0.005 mol) of diphenylamine, 0.94 g of sodium tert-butoxide, 0.04 g of palladium acetate, tris (tert-butyl) phosphine 0 .18 g and xylene 50 g were added to a four-necked flask and heated to reflux for 5 hours. Thereafter, the reaction solution was extracted with toluene and water, and the organic layer was concentrated under reduced pressure. Thereafter, the residue was separated and purified by column chromatography with toluene and hexane to obtain 2.54 g (yield 76%) of Compound (1). The obtained product was purified by toluene recrystallization and sublimation.

Examples 2-48
The organic EL element materials in Table 1 were synthesized according to the following reaction formulas (4) to (6).

Reaction formula (4)

In the reaction formula (4), R ^{1 to} R ⁸ and R ^{19 to} R ²⁸ correspond to the substituent of the general formula [1].

Reaction formula (5)

In the reaction formula (5), R ^{1 to} R ⁸ and R ^{19 to} R ²⁸ correspond to the substituent of the general formula [1].

Reaction formula (6)

In the reaction formula (6), R ^{1 to} R ⁸ , R ^{9 to} R ¹⁸ , and R ^{19 to} R ²⁸ correspond to the substituent of the general formula [1].

The structure of the compound of the present invention obtained using the above reaction formula (6) was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II) as in Synthesis Example 1. The measurement results of the mass spectrum of the synthesized compound are shown in Table 2. The compound numbers are the same as those described in Table 1 in this specification.

Table 2

Examples of Organic EL Device Hereinafter, organic EL devices using the compound of the present invention as a material for organic EL devices will be described with reference to the following examples, but the present invention is not limited to the following examples. In the examples, all mixing ratios are weight ratios unless otherwise specified. Vapor deposition (vacuum deposition) was performed in a vacuum of 10 ⁻⁶ Torr under conditions where temperature control such as heating and cooling of the substrate was not performed. The light emission characteristics of the element were measured using an organic EL element having a light emitting element area of 2 mm × 2 mm.

Example 49
PEDOT / PSS (poly (3,4-ethylenedioxy) -2,5-thiophene / polystyrene sulfonic acid, BAYTRON P VP CH8000 manufactured by Bayer) manufactured on a cleaned glass plate with an ITO electrode by a spin coating method Then, a hole injection layer having a film thickness of 60 nm was obtained by drying at 200 ° C. Next, a compound (A) shown below was dissolved in toluene at a concentration of 0.5 wt%, a 10 nm thick hole transport layer was formed by spin coating, and polymerized at 200 ° C. Subsequently, the compound (1) shown in Table (1) was dissolved in toluene at a concentration of 1.0 wt%, a light emitting layer having a thickness of 50 nm was formed by spin coating, and dried at 100 ° C. Further, a compound (B) shown below is vacuum-deposited thereon to form an electron injection layer having a film thickness of 20 nm, and then 1 nm of lithium fluoride and then 150 nm of aluminum (Al) are vapor-deposited thereon. An electrode was formed to obtain an organic EL element. The chromaticity when this element was driven to 6 V was green light emission of CIE (x, y) = (0.39, 0.57). The luminance half life when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was measured. In addition, initial luminance when driven at a current density of 12.5 mA / cm ² and luminance after continuous driving for 100 hours in an environment of 80 ° C. were measured. The results are shown in Table 3.

Examples 50-78
A device was produced in the same manner as in Example 49 except that a light emitting layer was produced using the compounds shown in Table 3 instead of the compound (1). The luminance half life when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was measured. Further, the initial luminance when driven at a current density of 15 mA / cm ² and the luminance after continuous driving for 100 hours in an environment of 80 ° C. were measured. The results are shown in Table 3.

Table 3

  As is apparent from Table 3, all the compounds of the present invention have a long lifetime and high brightness.

Example 79
On a glass plate with an ITO electrode, the compound (C) shown below is mixed with the compound (A) at a ratio of 10%, dissolved in toluene at a concentration of 0.5 wt%, and a film thickness of 40 nm is formed by spin coating. A hole transport layer was formed and polymerized at 200 ° C. Subsequently, the compound (1) shown in Table (1) was dissolved in toluene at a concentration of 1.0 wt%, a light emitting layer having a thickness of 50 nm was formed by spin coating, and dried at 100 ° C. Further, a compound (B) is vacuum-deposited thereon to form an electron injection layer having a film thickness of 20 nm, and then an electrode is formed by first depositing 1 nm of lithium fluoride and then 150 nm of aluminum (Al). Thus, an organic EL element was obtained. The chromaticity when this element was driven to 6 V was green light emission of CIE (x, y) = (0.39, 0.56). The luminance half life when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was measured. In addition, initial luminance when driven at a current density of 12.5 mA / cm ² and luminance after continuous driving for 100 hours in an environment of 80 ° C. were measured. The results are shown in Table 4.

Examples 80-110
A device was prepared in the same manner as in Example 79 except that the compound shown in Table 4 was used instead of the compound (1). All of these devices exhibited an external quantum efficiency of 4% or more at a DC voltage of 10V. Further, the luminance half life when driving at constant current with emission luminance of 500 (cd / m ² ) was measured. In addition, initial luminance when driven at a current density of 12.5 mA / cm ² and luminance after continuous driving for 100 hours in an environment of 80 ° C. were measured. The results are shown in Table 4.

Table 4

  As is clear from Table 4, all the compounds of the present invention have a long lifetime and high brightness.

Example 111
Solubility measurement of compound (1)

  The solubility of the compound (1) of the present invention in toluene was examined, and the results are shown in Table 5. As shown in Table 5, the compound (1) showed sufficient solubility for film formation in toluene.

Examples 112-158
Table 5 shows the results of examining the solubility in toluene using the compounds shown in Table 1 instead of the compound (1).

Table 5

  As described above, a high-performance EL element can be created by using the organic electroluminescence element material shown in the present invention. It is clear that remarkably high performance is exhibited with respect to the comparative compound, and high light emission efficiency, low drive voltage, long life, and high color purity light emission of the organic EL element can be achieved.

Claims (7)

An organic EL device material comprising a compound represented by the following general formula [1].
General formula [1]

Wherein R ^{1 to} R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted Or an unsubstituted monovalent aliphatic heterocyclic group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a cyano group, a substituted silyl group, an alkoxyl group, an aryloxy group, a substituted amino group, or the following general group Represents a group represented by the formula [2], and R ^{1 to} R ⁴ , R ^{5 to} R ⁸ , R ^{9 to} R ¹³ , R ^{14 to} R ¹⁸ , R ^{19 to} R ²³ , and R ^{24 to} R ²⁸ are The adjacent groups may be bonded to each other to form a ring, provided that any one of R ^{19 to} R ²³ and any one of R ^{24 to} R ²⁸ are independent of each other. And a group represented by the following general formula [2].)
General formula [2]

(Wherein X ¹ represents a direct bond, a substituted or unsubstituted divalent aliphatic hydrocarbon group, an oxygen atom, or a sulfur atom;
R ^{29 to} R ³³ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted Represents a monovalent aliphatic heterocyclic group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a cyano group, a substituted silyl group, an alkoxyl group, an aryloxy group, or a substituted amino group, and R ^{29 to} R ^{In 33} , adjacent groups may be bonded to each other to form a ring. ) The organic EL device material according to claim 1, comprising a compound represented by the following general formula [3].
General formula [3]

Wherein R ^{35 to} R ⁷⁰ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted Or an unsubstituted monovalent aliphatic heterocyclic group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a cyano group, a substituted silyl group, an alkoxyl group, an aryloxy group, or a substituted amino group, R ^{35 to} R ³⁸ , R ^{39 to} R ⁴² , R ^{43 to} R ⁴⁷ , R ^{48 to} R ⁵² , R ^{55 to} R ⁵⁹ , and R ^{64 to} R ⁶⁸ are each a ring in which adjacent groups are bonded to each other. May be formed.
X ² and X ³ each independently represent a direct bond, a substituted or unsubstituted divalent aliphatic hydrocarbon group, an oxygen atom, or a sulfur atom. ) The organic EL device material according to claim 1, wherein X ² and X ³ are a substituted or unsubstituted divalent aliphatic hydrocarbon group, an oxygen atom, or a sulfur atom.   In the organic EL element formed by forming a plurality of organic layers including a light emitting layer between a pair of electrodes, at least one of the organic layers comprises the organic EL element material according to any one of claims 1 to 3. Organic EL element.   4. An organic EL device comprising a light emitting layer or a plurality of organic layers including a light emitting layer formed between a pair of electrodes, wherein the light emitting layer is an organic material comprising the organic EL device material according to claim 3. EL element.   6. The organic EL device according to claim 4, wherein the light emitting layer is formed by coating.   The ink composition for organic EL elements which consists of the organic EL element material in any one of Claims 1-3, and an organic solvent.