JPH10284255A - Organic electroluminescent element material and organic electroluminescent element using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable light emission for a long time with a high light emission efficiency having its superior positive hole injection capacity and durability by employing an organic electroluminescent element material having a tri- phenylene structure at a center of a skeleton. SOLUTION: This organic electroluminescent element material is expressed by a formula. In the formula, wherein R<1> to R<6> denote a substituted or unsubstituted alkyl group, an aryl group, a complex circle group, or a substituted or unsubstituted single circle formed integrally with R<1> and R<2> , R<3> and R<4> , and R<5> and R<6> , or a condensed multiple circle, however, at least one pair of R<1> and R<2> , R<3> and R<4> , and R<5> and R<6> forms the above circle. X<1> to X<6> denote an oxygen atom, a sulfur atom, a hydrogen atom or a nitrogen atom in which an alkyl group or an aryl group are combined. Of a luminous layer or a layer forming an organic compound thin film of a plurality of layers containing the luminous layer, at least one layer contains an organic electroluminescent element material expressed by this formula.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device material having a triphenylene structure, and the compound can be used as an organic electroluminescent (EL) device used for a flat light source or display.

[0002]

2. Description of the Related Art Organic photoconductive materials have advantages such as low cost, processability and non-polluting properties, and many compounds have been proposed. For example, oxadiazole derivatives (U.S. Pat. No. 3,189,447), oxazole derivatives (U.S. Pat. No. 3,257,203), hydrazone derivatives (U.S. Pat. 59,1
No. 43, U.S. Pat. No. 4,150,978), and triarylpyrazoline derivatives (U.S. Pat. No. 3,820,989).
JP-A-51-93224, JP-A-55-1093
No. 8,667), arylamine derivatives (US Pat. No. 3,180,730, US Pat. No. 4,232,103).
JP-A-55-144250, JP-A-56-11
9,132), stilbene derivatives (JP-A-58-19)
No. 0,953, JP-A-59-195,658) and the like.

[0003] One of the techniques utilizing the hole transporting property of an organic photoconductive material is an organic EL device. 2. Description of the Related Art An EL element using an organic material is expected to be used as a solid-state light-emitting inexpensive large-area full-color display element, and many developments have been made. In general, an EL is composed of a light emitting layer and a pair of counter electrodes sandwiching the light emitting layer. The luminescence is
When an electric field is applied between both electrodes, electrons are injected from the cathode side, and holes are injected from the anode side. Further, the electrons are recombined with holes in the light emitting layer, and energy is emitted as light when the energy level returns from the conduction band to the valence band.

[0004] Conventional organic EL devices have a higher driving voltage and lower luminous luminance and luminous efficiency than inorganic EL devices.
In addition, the characteristic deterioration was remarkable, and it had not been put to practical use.
2. Description of the Related Art In recent years, an organic EL in which a thin film containing an organic compound having high fluorescence quantum efficiency that emits light at a low voltage of 10 V or less is laminated.
Devices have been reported and are of interest (see Applied Physics Letters, vol. 51, p. 913, 1987). This method uses a metal chelate complex for a phosphor layer and an amine compound for a hole injection layer to obtain high-luminance green light emission, and can be driven with a DC voltage of 6 to 7 V.
The maximum luminous luminance is 10,000 (cd / m ² ) and the maximum luminous efficiency is 1.5 (lm / W).

An organic EL device is a device having a light emitting layer containing an organic fluorescent compound between a metal cathode layer and a transparent anode layer. Also, in order to obtain high-luminance light emission at low voltage,
An element is formed by adding an electron injection layer and a hole injection layer. In these organic EL elements, excitons are generated by recombination of electrons injected from the cathode and holes injected from the anode, and light is emitted in the process of extinguishing the excitons (Japanese Patent Application Laid-Open No. H10-163,197). 5
9-194393, JP-A-63-295695). However, if light emission is continued for a long time by applying a DC voltage, crystallization of an organic compound or the like is promoted, a leak current easily flows through the element, and the element is destroyed. Therefore, as hole injection materials used for the hole injection layer, 4,4 ′, 4 ″ -tris (N, N′-diphenylamino) triphenylamine, 4,4 ′, 4 ″ -tris [N- ( 3-methylphenyl) -N-phenylamino]
It is improved by using a compound such as triphenylamine (JP-A-4-308688). These compounds have a three-dimensional coordination structure and are therefore difficult to be crystallized and have excellent thin film forming properties, but are still insufficient as organic thin films constituting organic EL devices. Therefore, there is a problem that the element is easily deteriorated during light emission.

As described above, the organic EL devices up to now are:
Luminous luminance and luminous stability during repeated use are not yet sufficient. For the development of organic EL devices having higher luminous luminance, high luminous efficiency and excellent stability during repeated use, excellent holes are required. It is desired to develop a durable hole injection material having an injection ability.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a durable hole injecting material having excellent hole injecting ability, and further to use this hole injecting material. Accordingly, an object of the present invention is to provide an organic EL element that can emit light with high luminous efficiency for a long time.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that at least one kind of hole injecting material represented by the general formula [1] has a large hole injecting ability, and an organic material prepared by using the same. The inventors have found that the EL element has excellent element characteristics and light emission life, and have reached the present invention.

That is, the present invention is an organic electroluminescent device material represented by the following general formula [1]. General formula [1]

Embedded image[Wherein, R¹~ R⁶Are each independently substituted or
Unsubstituted alkyl group, substituted or unsubstituted aryl
Group, substituted or unsubstituted heterocyclic group, or R¹When
R^Two, R^ThreeAnd R^Four, R^FiveAnd R⁶Are formed together
Substituted or unsubstituted monocyclic, substituted or unsubstituted condensed
Represents a polycyclic ring, provided that R¹And R^Two, R^ThreeAnd R ^Four, R^Five
And R⁶At least one pair forms the ring. X¹~ X
⁶Represents an oxygen atom, sulfur atom, hydrogen atom or alkyl
The nitrogen atom to which the group or aryl group may be
You. ]

Further, the present invention provides an organic electroluminescent device comprising a light emitting layer or a plurality of organic compound thin films including the light emitting layer formed between a pair of electrodes, wherein at least one layer contains the organic electroluminescent device material. This is an organic electroluminescence element which is a layer to be formed.

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

Further, the present invention provides an organic electroluminescence device comprising a light-emitting layer or a plurality of organic compound thin films including the light-emitting layer formed between a pair of electrodes, wherein the light-emitting layer contains the above-mentioned organic electroluminescence device material. This is an organic electroluminescence element which is a layer to be formed.

Further, the present invention provides an organic electroluminescence device comprising a light emitting layer or a plurality of organic compound thin films including the light emitting layer formed between a pair of electrodes, wherein the light emitting layer and at least one other layer are formed of the organic electroluminescent element. This is an organic electroluminescence device which is a layer containing a luminescence device material.

BEST MODE FOR CARRYING OUT THE INVENTION

R ¹ to R ⁴ of the compound represented by the general formula [1]
Examples of the substituted or unsubstituted alkyl group for R ⁶ include a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group,
Heptyl group, octyl group, stearyl group, trichloromethyl group, trifluoromethyl group, cyclopropyl group, cyclohexyl group, 1,3-cyclohexadienyl group, 2-
There is a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms such as a cyclopenten-1-yl group, a 2,4-cyclopentadiene-1-ylenyl group, a benzyl group and a 2,2-dimethylbenzyl group. .

The substituted or unsubstituted aryl groups include phenyl, tolyl, naphthyl, anthranyl, phenanthrenyl, fluorenyl, acenaphthyl, azulenyl, heptalenyl, acenaphthylenyl, pyrenyl, biphenyl, -Ethylbiphenyl group, terphenyl group, quarterphenyl group, benz [a] anthranyl group, triphenylenyl group, 2,3-
Examples include a benzofluorenyl group and a 3,4-benzopyrenyl group.

The substituted or unsubstituted heterocyclic group includes
Thionyl group, thiophenyl group, furanyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, 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, isothiazolyl group, isoxazolyl group, furazanyl group, phenoxazinyl group, benzothiazolyl group, benzoxazolyl group, benzimidazolyl group, 2-methylpyridyl group, 3-cyanopyridyl group, oxazolyl group, thiazolyl Group, imidazolyl group, oxadiazolyl group, thiadiazolyl group, imidadiazolyl group and the like. The above substituents and substitution positions are not specifically limited.

Representative examples of the substituent which may be substituted on the alkyl group, the aryl group and the heterocyclic group of the compound represented by the general formula [1] include the following substituents. Halogen atoms include fluorine, chlorine, bromine and iodine. Further, there are a nitro group, a cyano group, a carbonyl group, a hydroxyl group, a mercapto group and the like. Examples of the substituted or unsubstituted alkyl group include methyl, ethyl, propyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, stearyl, and trichloro. Methyl group, trifluoromethyl group, cyclopropyl group, cyclohexyl group, 1,3-cyclohexadienyl group, 2-cyclopenten-1-yl group, 2,
A 4-cyclopentadiene-1-yridenyl group and the like.
Examples of the substituted or unsubstituted alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group,
There are c-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, stearyloxy group, trifluoromethoxy group and the like. Examples of the substituted or unsubstituted thioalkoxy group include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a sec-butylthio group,
Examples include a tert-butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, and an octylthio group.

The mono- or di-substituted amino groups include methylamino, dimethylamino, ethylamino, diethylamino, dipropylamino, dibutylamino, diphenylamino, bis (acetooxymethyl)
There are an amino group, a bis (acetooxyethyl) amino group, a bis (acetooxypropyl) amino group, a bis (acetooxybutyl) amino group, a dibenzylamino group and the like. Examples of the substituted or unsubstituted aryloxy group include a phenoxy group, a p-tert-butylphenoxy group, and a 3-fluorophenoxy group. Examples of the substituted or unsubstituted arylthio group include a phenylthio group and a 3-fluorophenylthio group. Examples of the substituted or unsubstituted aryl group include phenyl, biphenyl, triphenyl, terphenyl, 3-nitrophenyl, 4-methylthiophenyl, 3,5-dicyanophenyl, o
-, M- and p-tolyl groups, xylyl groups, o-, m-
And p-cumenyl group, mesityl group, pentalenyl group,
Indenyl, naphthyl, azulenyl, heptalenyl, acenaphthylenyl, phenalenyl, fluorenyl, anthryl, anthraquinolyl, 3-methylanthryl, phenanthryl, triphenylenyl, pyrenyl, chrysenyl, 2-ethyl- 1-chrysenyl group, picenyl group, perylenyl group, 6-chloroperylenyl group, pentaphenyl group, pentacenyl group, tetraphenylenyl group, hexaphenyl group, hexacenyl group,
Rubicenyl group, coronenyl group, trinaphthylenyl group, heptaphenyl group, heptaenyl group, pyranthenyl group,
Ovalenyl group and the like.

The substituted or unsubstituted heterocyclic group includes
Thionyl group, thiophenyl group, furanyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, 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, isothiazolyl group, isoxazolyl group, furazanyl group, phenoxazinyl group, benzothiazolyl group, benzoxazolyl group, benzimidazolyl group, 2-methylpyridyl group, 3-cyanopyridyl group, oxazolyl group, thiazolyl Groups, imidazolyl groups, oxadiazolyl groups, thiadiazolyl groups, imidadiazolyl groups, carbazole groups, indole groups and the like, but are not specifically limited to the above substituents.

In the general formula [1], R ¹ and R ² , R ³ and R ⁴ ,
Examples of the ring formed by combining R ⁵ and R ⁶ include a monocyclic cycloalkyl ring, a monocyclic aryl ring, a condensed polycyclic aryl ring, a monocyclic heterocyclic ring, and a condensed polycyclic heterocyclic ring. As the cycloalkyl ring, a cyclomethyl ring, a cycloethyl ring, a cyclopropyl ring, a cyclobutyl ring, a cyclopentyl ring,
There are a cyclohexyl ring, a cycloheptyl ring, a cyclooctyl ring and the like.

The monocyclic or condensed polycyclic aryl ring includes a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, an acenaphthalene ring, an azurenium ring, a heptalene ring, a pyrene ring, a biphenyl ring,
Examples include a 4-ethylbiphenyl ring, a terphenyl ring, a benz [a] anthracene ring, a triphenylene ring, a 2,3-benzofluorene ring, and a 3,4-benzopyrene ring.

As the monocyclic or condensed polycyclic heterocyclic ring, 1
Crown ether rings such as 2-crown ring, 15-crown ring, 18-crown ring, indolyl ring, quinolyl ring,
Isoquinolyl ring, quinoxanilyl ring, quinazolinyl ring,
Examples include a carbazolinyl ring, a phenazinyl ring, a furfuryl ring, an isothiazolyl ring, a benzimidazolyl ring, a 1-tetralyl ring, and a 2-tetralyl ring. Examples of the substituent for the above ring include the substituents of R ^{1 to} R ⁶ described above.

X ^{1 to} X ⁶ in the general formula [1] represent an oxygen atom,
Represents a sulfur atom or a nitrogen atom to which a hydrogen atom or an alkyl group or an aryl group may be bonded. Examples of the alkyl group or aryl include a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group described for the substituents of R ^{1 to} R ⁶ .

Representative examples of the compound represented by the general formula [1] are specifically shown in Table 1, but are not limited thereto.

[0025]

[Table 1]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

The organic EL device material of the present invention may be used in a mixture with another hole or electron injection material in the same layer.

The organic EL device is a device in which a single or multilayer organic thin film is formed between an anode and a cathode. In the case of a single layer type, a light emitting layer is provided between an anode and a cathode. The light-emitting layer contains a light-emitting material and may further contain a hole-injection material or an electron-injection material for transporting holes injected from an anode or electrons injected from a cathode to the light-emitting material. The light emitting material may have a hole injecting property or an electron injecting property. The multilayer type includes (anode / hole injection layer / light-emitting layer / cathode), (anode / light-emitting layer / electron injection layer /
There is an organic EL device having a multilayer structure of (cathode) and (anode / hole injection layer / emission layer / electron injection layer / cathode). The compound of the general formula [1] can be used in any device configuration. The compound of the general formula [1] can be used in any of the hole injection layer and the light emitting layer. Since the organic EL device material of the present invention has a function of injecting holes from the anode to the organic layer and a function of transporting the injected holes and injecting them into the light emitting layer, the hole injection layer has two or more layers. Even if
It can be used for any hole injection layer. Further, it can be used as a light emitting material. Furthermore, it is also possible to add an electron-withdrawing substituent and use it as an electron-injection material. Since the thin film formed of the compound represented by the general formula [1] has an amorphous property, it is advantageous in long-term storage when the thin film is formed, light emission life when the element is driven, and the like. In addition, the compound of the general formula [1]
Since the adhesion to the metal electrode such as is good and the ionization potential of the film film is low, it is advantageous for hole injection from the anode.
It is more advantageous to use the compound of the general formula [1] for the hole injection layer on the metal electrode (anode) side.

In the light emitting layer, if necessary, a light emitting material, a doping material, a hole injection material or an electron injection material can be used in addition to the compound of the general formula [1] of the present invention. In the case of a two-layer structure, the light emitting layer and the hole injection layer are separated. With this structure, the efficiency of hole injection from the hole injection layer to the light emitting layer is improved, and the light emission luminance and the light emission efficiency can be increased. In this case, for light emission, it is desirable that the light emitting material used for the light emitting layer itself has an electron injecting property, or that the electron injecting material is added to the light emitting layer. Another layer configuration includes a two-layer structure including a light emitting layer and an electron injection layer. In this case, it is desirable that the light emitting material itself has a hole injecting property, or that the hole injecting material is added to the light emitting layer.

The three-layer structure has a light emitting layer, a hole injection layer, and an electron injection layer to improve the efficiency of recombination of holes and electrons in the light emitting layer. In this manner, by making the organic EL element have a multilayer structure, it is possible to prevent a decrease in luminance and life due to quenching. In such a device having a multilayer structure, a light emitting material, a doping material, a hole injection material for transporting carriers, and an electron injection material can be used in combination, if necessary. In addition, each of the hole injection layer, the light emitting layer, and the electron injection layer may be formed of two or more layers.

As the conductive material used for the anode of the organic EL device, those having a work function of more than 4 eV are suitable, and include carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, and platinum. , Palladium and the like, alloys thereof, metal oxides such as tin oxide and indium oxide called ITO substrates and NESA substrates, and organic conductive resins such as polythiophene and polypyrrole are used. As the conductive material used for the cathode, those having a work function smaller than 4 eV are preferable, and magnesium, calcium, tin, lead, titanium,
Yttrium, lithium, ruthenium, manganese and the like and alloys thereof are used. Examples of the alloy include magnesium / silver, magnesium / indium, and lithium / aluminum, but are not limited thereto, and the metal ratio of the alloy is not limited. Also,
The anode and the cathode may be formed of two or more layers if necessary.

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

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

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

The light emitting material or doping material that can be used in the organic EL device of the present invention includes anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein, perylene, phthaloperylene, naphthaloperylene, perinone, phthaloperinone,
Naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, benzoquinoline metal complex, imine, diphenylethylene, vinyl anthracene , Diaminocarbazole, triphenylamine, benzidine-type triphenylamine, styrylamine-type triphenylamine, diamine-type triphenylaminepyran, thiopyran, polymethine, merocyanine, imidazole chelated oxinoid compounds, quinacridone, rubrene, and derivatives thereof. However, the present invention is not limited to these.

The hole injecting material that can be used in combination with the organic EL device material of the general formula [1] has the ability to transport holes and has an excellent hole injecting effect on the light emitting layer or the light emitting material. In addition, a compound that prevents excitons generated in the light emitting layer from moving to the electron injection layer or the electron injection material and has excellent thin film forming ability can be used. Specifically, phthalocyanine compounds, naphthalocyanine compounds, porphyrin compounds, oxadiazole, triazole, imidazole, imidazolone, imidazolethione, pyrazoline,
Pyrazolone, tetrahydroimidazole, oxazole, oxadiazole, hydrazone, acylhydrazone, polyarylalkane, stilbene, butadiene,
Benzidine-type triphenylamine, styrylamine-type triphenylamine, diamine-type triphenylamine and the like, and derivatives thereof, and polyvinyl carbazole,
Although there are polymer materials such as polysilane and conductive polymer,
It is not limited to these.

The electron injecting material has a capability of transporting electrons, has an excellent electron injecting effect on the light emitting layer or the light emitting material, and has a hole injecting layer or hole injection of excitons generated in the light emitting layer. Compounds that prevent transfer to a material and have excellent thin film forming ability are exemplified. For example, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxadiazole, perylenetetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane,
Examples include, but are not limited to, anthrones and derivatives thereof. Alternatively, an electron accepting material may be added to the hole injecting material and an electron donating material may be added to the electron injecting material to sensitize the material.

The compound of the general formula [1] of the present invention can be used for any layer, and in addition to the compound of the general formula [1], a light emitting material, a doping material, a hole injection material and an electron injection material May be contained in the same layer. In order to improve the stability of the organic EL device obtained according to the present invention with respect to temperature, humidity, atmosphere, etc., a protective layer is provided on the surface of the device, or silicon oil or the like is sealed to protect the entire device. It is also possible. As described above, in the present invention, since the compound of the general formula [1] was used for the organic EL device, the luminous efficiency and the luminous brightness could be increased. Also,
This element is stable against heat and current, and can obtain practically usable emission luminance at a low drive voltage. I was able to. The organic EL element of the present invention can be used for flat panel displays such as wall-mounted televisions,
The flat illuminant can be applied to light sources such as copiers and printers, light sources such as liquid crystal displays and instruments, display boards, and sign lamps, and its industrial value is very large.

[0044]

The present invention will be described below in more detail with reference to examples. According to DSC analysis, many of the compounds represented by the general formula [1] of the present invention have a glass transition temperature of 10
0 ° C, melting point 250 ° C or higher, decomposition point 300 ° C or higher,
Conventionally used as an amorphous hole injection material,
4,4 ', 4 "-tris [N- (3-methylphenyl)
-N-phenylamino] triphenylamine,
The glass transition point temperature, melting point, and decomposition point are high, and it can be seen that the organic EL device has high heat resistance as a hole injecting material. In addition, all compounds represented by the general formula [1] of the present invention have low crystallinity and are non-crystalline compounds.
It has good adhesion to the anode substrate and the organic thin film layer, and has great advantages in terms of resistance to the environment as an organic thin film, emission life when the organic EL element is driven, and storage stability of the element.

Example 1 Compound (1) was vacuum-deposited on a washed glass plate with an ITO electrode to obtain a 30-nm-thick hole injection layer. Next, a tris (8-hydroxyquinolinato) aluminum complex is vacuum-deposited to form a 50-nm-thick light-emitting layer, on which a 150-nm-thick electrode is formed using an alloy of magnesium and silver mixed at a ratio of 10: 1. Thus, an organic EL device was obtained. The hole injection layer and the light emitting layer were deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This device has a light emission luminance of 120 (cd / m ² ) at a DC voltage of 5 V, a maximum light emission luminance of 19000 (cd / m ² ), and a light emission efficiency of 2.1 (lm).
/ W).

Example 2 An organic EL device was manufactured in the same manner as in Example 1, except that the hole injection layer was formed by spin coating the compound (2) dissolved in chloroform. This element has a DC voltage of 5
At V, the light emission luminance is 200 (cd / m ² ), and the maximum light emission luminance is 16
000 (cd / m ² ) and luminous efficiency of 2.0 (lm / W) were obtained.

Example 3 A compound (4) was vacuum-deposited on a washed glass plate with an ITO electrode to obtain a hole injection layer having a thickness of 40 nm. Next, N, N'-diphenyl-N, N '-(3-methylphenyl) -1,1'-biphenyl-4,4'-diamine is vacuum-deposited to form a second hole injection layer having a thickness of 10 nm. I got Further, a tris (8-hydroxyquinolinato) aluminum complex was vacuum-deposited to form a 40-nm-thick electron-injection light-emitting layer, on which magnesium and silver were added at 10:
An electrode having a thickness of 150 nm is formed from the alloy mixed in Step 1,
An organic EL device was obtained. 10 ^{−6 for the} hole injection layer and the light emitting layer
Vapor deposition was performed in a Torr vacuum at a substrate temperature of room temperature. This device has a light emission luminance of 240 (cd) at a DC voltage of 5 V.
/ M ² ), a maximum emission luminance of 27000 (cd / m ² ), and a light emission efficiency of 2.4 (lm / W).

Example 4 On a washed glass plate with ITO electrodes, 4, 4 ', 4 "
-Tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine was vacuum deposited to a film thickness of 40
As a result, a hole injection layer having a thickness of nm was obtained. Next, the compound (3) was vacuum-deposited to obtain a second hole injection layer having a thickness of 10 nm. Further, a tris (8-hydroxyquinolinato) aluminum complex was vacuum-deposited to form an electron-injection-type light-emitting layer having a thickness of 40 nm. Form an electrode and use organic EL
An element was obtained. The hole injection layer and the light emitting layer are 10 ^-6 Torr
Vacuum was deposited in a vacuum at a substrate temperature of room temperature. This device has a light emission luminance of 260 (cd / m ² ) at a DC voltage of 5 V,
1. Maximum luminous luminance 36000 (cd / m ² ), luminous efficiency
Emission characteristics of 8 (lm / W) were obtained.

Example 5 In the first hole injection layer, 4,4 ′, 4 ″ -tris [N- (1
-Naphthyl) -N-phenylamino] triphenylamine, except that organic EL was used in the same manner as in Example 4.
An element was manufactured. This device has an emission luminance of 280 (cd / m ² ) at a DC voltage of 5 V and a maximum emission luminance of 32000 (cd / m ² ).
/ M ² ) and luminous efficiency of 2.6 (lm / W).

Example 6 Compound (17) was placed on a washed glass plate with an ITO electrode.
Was dissolved in chloroform, and a hole injection layer having a thickness of 40 nm was obtained by a spin coating method. Next, a tris (8-hydroxyquinolinato) aluminum complex was vacuum-deposited to form an electron-injection-type light-emitting layer having a thickness of 40 nm, and a 100-nm-thick alloy of magnesium and silver mixed at a ratio of 10: 1 was formed thereon. Electrodes were formed to obtain an organic EL device.
The light emitting layer was deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This element has a DC voltage of 5 V and an emission luminance of 2
30 (cd / m ² ), maximum emission luminance 26000 (cd / m ² )
m ² ) and luminous efficiency of 2.5 (lm / W).

Examples 7 to 27 The compounds shown in Table 1 were vacuum-deposited on the cleaned glass plate with ITO electrodes to obtain a hole injection layer having a thickness of 40 nm. Then, 4,4'-bis [N- (1-naphthyl)-
[N-phenylamino] biphenyl was vacuum-deposited to obtain a 10-nm-thick hole transport layer. Further, a tris (8-hydroxyquinolinato) aluminum complex was vacuum-deposited to form a 50 nm-thick light-emitting layer, and bis (2-methyl-8-hydroxyquinolinato) (1-phenolate) was further formed.
A gallium complex is vacuum-deposited to form an electron-injection layer having a thickness of 30 nm.
An electrode having a thickness of 150 nm is formed from the alloy mixed in Step 1,
An organic EL device was obtained. 10 ^{−6 for the} hole injection layer and the light emitting layer
Vapor deposition was performed in a Torr vacuum at a substrate temperature of room temperature. This device had the emission characteristics shown in Table 2.

[0052]

[Table 2]

Example 28 4,4′-Bis [N- (1-naphthyl) -N-phenylamino] biphenyl was vacuum-deposited on a washed glass plate with an ITO electrode, and a hole having a thickness of 40 nm was injected. Layer obtained. Next, the compound (6) is vacuum-deposited to a thickness of 50 nm.
And a tris (8-hydroxyquinolinato) aluminum complex was further vacuum-deposited to a thickness of 40 nm.
Was formed, and an electrode having a thickness of 150 nm was formed on the electron injection layer using an alloy in which magnesium and silver were mixed at a ratio of 10: 1 to obtain an organic EL device. The hole injection layer and the light emitting layer were deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This element has a light emission luminance of 480 at a DC voltage of 5 V.
(Cd / m ² ), maximum emission luminance 27000 (cd / m ² )
m ² ) and luminous efficiency of 2.3 (lm / W).

Example 29 Compound (2) was vacuum-deposited on a washed glass plate with an ITO electrode to obtain a hole injection layer having a thickness of 40 nm. Next, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl is vacuum-deposited to a thickness of 10 nm.
Was obtained. Further, N, N, N ', N'-
[4- (α, α′-dimethylbenzyl) phenyl] -anthranyl-9,10-diamine was vacuum-deposited to a film thickness of 5
A 0 nm light-emitting layer was formed, and a tris (8-hydroxyquinolinato) aluminum complex was further vacuum-deposited to a thickness of 4 nm.
An electron injection layer having a thickness of 0 nm was formed, and an electrode having a thickness of 150 nm was formed thereon using an alloy in which magnesium and silver were mixed at a ratio of 10: 1 to obtain an organic EL device. The hole injection layer and the light emitting layer were deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This device emits 1 light at a DC voltage of 5V.
200 (cd / m ² ), maximum emission luminance 69000 (cd
/ M ² ) and luminous efficiency of 5.2 (lm / W).

Example 30 After the compound (2) was vacuum-deposited, 65
An organic EL device was manufactured in the same manner as in Example 29 except that the heating was performed at a temperature of 3 ° C. for 3 hours. This device has a light emission luminance of 1200 (cd / m ² ) at a DC voltage of 5 V and a maximum light emission luminance of 7600.
Light emission characteristics of 0 (cd / m ² ) and luminous efficiency of 5.9 (lm / W) were obtained. By heating, the light emission characteristics were improved. This is presumed that the compound (2) changed to an orientation state advantageous for hole injection and transport by heating.

Example 31 Compound (4) was vacuum-deposited on a washed glass plate with an ITO electrode to obtain a hole injection layer having a thickness of 40 nm. Next, the compound (21) and rubrene are vacuum-deposited at a weight ratio of 10: 1 to form a 50-nm-thick light-emitting layer, and a tris (8-hydroxyquinolinato) aluminum complex is further vacuum-deposited to form a 40-nm-thick electron. An injection layer was formed, and an electrode having a thickness of 150 nm was formed thereon using an alloy in which magnesium and silver were mixed at a ratio of 10: 1 to obtain an organic EL device. The hole injection layer and the light emitting layer were deposited in a vacuum of 10 ^-6 Torr at a substrate temperature of room temperature. This device has a light emission luminance of 680 (cd / m ² ) at a DC voltage of 5 V and a maximum light emission luminance of 4
7000 (cd / m ² ), luminous efficiency 3.3 (lm / W)
Was obtained.

Example 32 Tris (8-hydroxyquinolinato) aluminum complex and quinacridone were deposited in a weight ratio of 20: 1 to form a film having a thickness of 40%.
An organic EL device was produced in the same manner as in Example 7, except that a light emitting layer having a thickness of 10 nm was obtained. This device has a light emission luminance of 600 (cd / m ² ) at a DC voltage of 5 V and a maximum light emission luminance of 40000.
(Cd / m ² ) and luminous efficiency of 3.9 (lm / W) were obtained.

Example 33 An organic E compound was prepared in the same manner as in Example 32 except that the compound (20) was deposited in place of the tris (8-hydroxyquinolinato) aluminum complex to obtain an electron injection layer having a thickness of 40 nm.
An L element was produced. This device has a light emission luminance of 600 (cd / m ² ) at a DC voltage of 5 V and a maximum light emission luminance of 42000 (c / m ² ).
d / m ² ) and luminous efficiency of 4.4 (lm / W).

Comparative Example 1 Instead of compound (1), 4,4 ′, 4 ″ -tris [N-
An organic EL device was prepared in the same manner as in Example 1, except that (3-methylphenyl) -N-phenylamino] triphenylamine was used. This element has a DC voltage of 5 V
And a light emission luminance of about 160 (cd / m ² ) and a light emission efficiency of 1.2
(Lm / W) was obtained.

Comparative Example 2 In place of compound (27), 4,4 ′, 4 ″ -tris [N
An organic EL device was prepared in the same manner as in Example 55 except that-(3-methylphenyl) -N-phenylamino] triphenylamine was used. This device has a luminous luminance of about 550 (cd / m ² ) at a DC voltage of 5 V and a luminous efficiency of 3.
A light emission characteristic of 5 (lm / W) was obtained.

When all the organic EL devices shown in this example were continuously emitted at 3 (mA / cm ² ),
Although the luminance of 50% or more of the initial luminance could be observed for 1000 hours or more, the devices of Comparative Example 1 and Comparative Example 2 were continuously illuminated under the same conditions.
0% or less, and the number of dark spots, which are non-light emitting portions of the device, also increased. The reason for the above results is that, since the compound of the present invention is a non-planar compound, it is possible to form a non-crystalline thin film when forming a thin film, because of the triphenylene ring in the compound. The hole injection property is improved, and the hole injection property of the organic EL element is improved. Furthermore, since the heat resistance is also improved, the resistance to heat generation during continuous light emission, the ability to inject holes from the substrate, and the adhesion to the substrate are also improved. Also, when used as an electron injecting material, it is possible to form an amorphous thin film, and the compound has many condensed aromatic rings in the compound and has an electron withdrawing group. The injection property is improved, and the electron injection property of the organic EL element is improved. In addition, it exhibited effective characteristics as a light emitting material.

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

[0063]

According to the present invention, it is possible to obtain a compound having an organic EL device characteristic having an excellent hole, electron injecting property or light emitting characteristic. By using the compound provided by the present invention, an organic EL device having higher luminous efficiency and higher luminance than conventional ones and capable of long-term light emission and storage can be obtained.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Okutsu 2-3-113 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd.

Claims (5)

[Claims] An organic electro-chemical compound represented by the following general formula [1]:
Troll luminescence element material. General formula [1][Wherein, R¹~ R⁶Are each independently substituted or
Unsubstituted alkyl group, substituted or unsubstituted aryl
Group, substituted or unsubstituted heterocyclic group, or R¹When
R^Two, R^ThreeAnd R^Four, R^FiveAnd R⁶Are formed together
Substituted or unsubstituted monocyclic, substituted or unsubstituted condensed
Represents a polycyclic ring, provided that R¹And R^Two, R^ThreeAnd R ^Four, R^Five
And R⁶At least one pair forms the ring. X¹~ X
⁶Represents an oxygen atom, a sulfur atom, a hydrogen atom or an
A nitrogen atom to which a alkyl or aryl group may be attached
Represents ] 2. An organic electroluminescence device comprising a light-emitting layer or a plurality of organic compound thin films including a light-emitting layer formed between a pair of electrodes, wherein at least one layer contains the organic electroluminescence device material according to claim 1. Organic electroluminescent element which is a layer to be formed. 3. The organic electroluminescence device material according to claim 1, wherein a hole injection layer is provided in the organic electroluminescence device having a light emitting layer or a plurality of organic compound thin films including the light emitting layer formed between a pair of electrodes. An organic electroluminescence device which is a layer containing: 4. An organic electroluminescence device in which a light emitting layer or a plurality of organic compound thin films including a light emitting layer is formed between a pair of electrodes, wherein the light emitting layer contains the organic electroluminescent device material according to claim 1. Organic electroluminescent element which is a layer to be formed. 5. An organic electroluminescent device comprising a plurality of organic compound thin films including a light emitting layer formed between a pair of electrodes, wherein the light emitting layer and at least another layer are formed of the organic electroluminescent device material according to claim 1. An organic electroluminescence device which is a layer containing: