JP2005100881A - Organic electroluminescent element, display device and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroliminescent element of excellent luminous efficiency, a display device or a lighting device equipped with the element. <P>SOLUTION: The organic electroluminescent element has a repetition unit expressed by general formula (1) of which, a core compound is a light emitting compound, on at least one layer of the organic layer, at least in second generation and after, and contains a compound having a multiple branching structure which has at least one partial structure selected from among a boron derivative, a silol derivative, a phenanthroline derivative, an azacarbazole derivative, a styryl derivative and a fluorine substituted triaryl amine derivative in a molecule. In formula (1), Ar<SB>1</SB>is an arylene group or a hetero arylene group which may have a substituted group, and L<SB>1</SB>is any one linking group selected from among a linkage group 1 expressed by the above figure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic electroluminescence element (hereinafter sometimes referred to as an organic EL element), a display device, and a lighting device.

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. As a component of ELD, an inorganic electroluminescent element and an organic electroluminescent element are mentioned. Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  On the other hand, an organic electroluminescence device has a structure in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer and recombines them to exciton (exciton). ) And emits light using the emission of light (fluorescence / phosphorescence) when the exciton is deactivated, and can emit light at a voltage of several V to several tens of V. Since it is a self-luminous type, it has a wide viewing angle, high visibility, and since it is a thin-film type complete solid-state device, it has attracted attention from the viewpoints of space saving and portability.

  For the development of organic electroluminescence elements for practical use in the future, organic electroluminescence elements that emit light efficiently and with high brightness with lower power consumption are desired. For example, stilbene derivatives, distyrylarylene derivatives Alternatively, a technique for doping a tristyrylarylene derivative with a small amount of phosphor to improve emission luminance and extend the lifetime of the device (for example, see Patent Document 1), using an 8-hydroxyquinoline aluminum complex as a host compound, An element having an organic light-emitting layer doped with a trace amount of phosphor (for example, see Patent Document 2), an element having an organic light-emitting layer doped with a quinacridone dye as a host compound using 8-hydroxyquinoline aluminum complex (For example, refer to Patent Document 3).

  In the technique disclosed in the above document, when the emission from the excited singlet is used, the generation ratio of the singlet exciton and the triplet exciton is 1: 3, so the generation probability of the luminescent excited species is 25%. Since the light extraction efficiency is about 20%, the limit of the external extraction quantum efficiency (ηext) is set to 5%.

  However, since Princeton University has reported on organic electroluminescence devices using phosphorescence emission from excited triplets (see, for example, Non-Patent Document 1), research on materials that exhibit phosphorescence at room temperature has become active. (For example, see Non-Patent Document 2 and Patent Document 4).

  When excited triplets are used, the upper limit of internal quantum efficiency is 100%, so in principle the luminous efficiency is four times that of excited singlets, and the performance is almost the same as that of cold cathode tubes. It can be applied to and attracts attention.

  For example, many compounds have been studied focusing on heavy metal complexes such as iridium complex systems (see, for example, Non-Patent Document 3).

  Further, studies using tris (2-phenylpyridine) iridium as a dopant have been made (for example, see Non-Patent Document 2).

In addition, L ₂ Ir (acac) (wherein L represents a bidentate ligand and acac represents acetylacetone), for example, (ppy) ₂ Ir (acac) (for example, see Non-Patent Document 4) as a dopant. Further, as a dopant, tris (2- (p-tolyl) pyridine) iridium (Ir (ptpy) ₃ ), tris (benzo [h] quinoline) iridium (Ir (bzq) ₃ ), Ir (bzq) ₂ ClP (Bu ) Examination using ₃ etc. (for example, refer nonpatent literature 5) is performed.

  In addition, in order to obtain high luminous efficiency, a hole transporting compound is used as a host of the phosphorescent compound (see, for example, Non-Patent Document 6).

  Further, various electron transporting materials are used as phosphorescent compound hosts by doping them with a novel iridium complex (for example, see Non-Patent Document 4). Furthermore, high luminous efficiency is obtained by introducing a hole blocking layer (see, for example, Non-Patent Document 5).

  However, although the external extraction efficiency of about 20%, which is the theoretical limit, has been achieved for green light emission, there is a problem that the efficiency is greatly reduced particularly at high luminance light emission, and other light emission colors are still sufficient. For example, Patent Document 5 can be cited as an example of studying an organic electroluminescence element that realizes high-efficiency blue light emission. In addition, for organic electroluminescence elements for practical use in the future, it is desired to develop organic electroluminescence elements that emit light with high power and efficiency with low power consumption. In addition, development of an organic electroluminescence element that emits light for a long lifetime is also desired.

  Regarding phosphorescent dopants used in organic EL elements, there have been very many disclosures such as Patent Documents 6, 7, 8, 9, 10, and 11 so far. Many of these disclosures aim at high luminous efficiency, high color purity, and excellent durability. However, to date, the elements required as phosphorescent dopant compounds used in organic EL devices are still not sufficient, and further improvements are required.

  On the other hand, in increasing the area of an organic EL element, it is known that the production by vacuum vapor deposition, which is common in the production of an organic EL element using a low molecular weight compound, has problems in terms of equipment and energy efficiency. Therefore, it is considered that a printing method including an ink jet method or a screen printing method or a coating method such as spin coating or cast coating is desirable. For example, when a white light emitting device is manufactured, a plurality of luminescent compounds having different emission maximum wavelengths must be provided in the light emitting layer. Particularly in the case of a phosphorescent light emitting device, a plurality of phosphorescent compounds are formed by vacuum evaporation. It is difficult to deposit the conductive dopant at the same ratio every time, and it is expected that there will be a problem in the yield during manufacturing. However, the organic EL element is formed by the printing method or the coating method using a material having excellent solvent solubility. If it becomes possible to prepare the phosphorescent dopant in the same ratio, any solution of the organic EL element to be manufactured can be prepared by preparing a solution in which the phosphorescent dopant is mixed in the same ratio. Thus, it becomes possible to stably produce a white light-emitting organic EL element having the same luminescent color.

  From such a viewpoint, as an attempt to improve the solvent solubility of the phosphorescent dopant used in the organic EL device, it has an oligophenylene moiety having a substituent at the 50th Applied Physics Lecture (see Non-Patent Document 9). Examples of phosphorescent dopants have been reported. This phosphorescent dopant not only improves the solubility, but also introduces bulky substituents to prevent the phosphorescent dopants from approaching each other, and the phosphorescent compound approaches the emission process. It is also considered that so-called concentration quenching is suppressed.

  Furthermore, in recent years, in addition to the suppression of solvent solubility and concentration quenching, a so-called dendrimer structure in which substituents are branched in multiples to form a dendritic structure in order to increase the energy transfer efficiency, which is important in the light emission process of organic EL elements, has been developed. Phosphorescent dopants possessing are beginning to be proposed. Examples of such research are reported in Non-Patent Documents 7, 8, 9 and the like.

All reported examples of these dendrimer-type phosphorescent dopants are relatively young generation dendrimers that are unbranched or have simple substituents introduced, each with interesting results. However, in the practical application of organic EL devices using them, it cannot be said that they have sufficient performance to meet market demands at this stage, and improvements in these phosphorescent dopants are still expected. Yes.
Japanese Patent No. 3093796 Japanese Unexamined Patent Publication No. 63-264692 JP-A-3-255190 US Pat. No. 6,097,147 JP 2002-1000047 A JP 2001-181616 A JP 2001-247859 A Japanese Patent Laid-Open No. 2002-83684 JP 2002-175484 A JP 2002-338588 A JP 2003-7469 A M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) S. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001) M.M. E. Thompson et al. , The 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu) Moon-Jae Youn. Og, Tetsuo Tsutsui et al. , The 10th International Works on Organic and Organic Electroluminescence (EL'00, Hamamatsu) Ikai et al. , The 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu) Applied Physics Letters, Vol. 80, page 2645 IDW02 Proceedings (1124 pages) Proceedings of the 50th Applied Physics Lecture

  The present invention has been made in view of such problems, and an object of the present invention is to provide an organic electroluminescence element having high luminous efficiency and a long lifetime, and a display device or an illumination device including the organic electroluminescence element. It is to be.

The object of the present invention is achieved by the following constitution.
(Claim 1)
An organic electroluminescent device having at least one organic layer between a cathode and an anode, wherein the core compound is a luminescent compound in at least one layer of the organic layer and is represented by the following general formula (1) Multi-branched structure compound having at least a second generation unit and having in its molecule at least one partial structure selected from boron derivatives, silole derivatives, phenanthroline derivatives, azacarbazole derivatives, styryl derivatives, and fluorine-substituted triarylamine derivatives An organic electroluminescence device comprising:

[In the formula, Ar ₁ represents an arylene group or a heteroarylene group which may have a substituent. L ₁ represents any linking group selected from the following linking group group 1. ]

[R _{1 to} R ₆ each independently represents an alkyl group or an aryl group, and R ₃ and R ₄ , or R ₅ and R ₆ may be linked to each other to form a ring. ]
(Claim 2)
The organic electroluminescence device according to claim 1, wherein the light emitting compound is a fluorescent compound.
(Claim 3)
The organic electroluminescence device according to claim 1, wherein the light emitting compound is a phosphorescent compound.
(Claim 4)
The organic electroluminescent device according to claim 3, wherein the phosphorescent compound is an organometallic complex.
(Claim 5)
The organic electroluminescence device according to claim 4, wherein the organometallic complex has a partial structure represented by any one of the following general formulas (2) to (5).

[In General Formula (2), R _{35 to} R ₄₂ each independently represents a hydrogen atom, a bond, or a substituent, and R _{35 to} R ₄₂ are adjacent to each other to form a ring. May be. M ₁ represents a metal atom.
In the general formula (3), Z ₁ and Z ₂ each independently represents an atomic group necessary for forming an aromatic ring together with a carbon atom and a nitrogen atom. M ₂ represents a metal atom.
In the general formula (4), R _{43 to} R ₄₈ each independently represent a hydrogen atom, a bond, or a substituent, and R _{43 to} R ₄₈ are bonded together to form a ring. Also good. M ₃ represents a metal atom.
In General Formula (5), Y represents a divalent linking group, R _{49 to} R ₅₆ each independently represent a hydrogen atom, a bond, or a substituent, and groups adjacent to R _{49 to} R ₅₆ May be combined with each other to form a ring. M ₄ represents a metal atom. ]
(Claim 6)
The organic electroluminescence device according to claim 1, wherein Ar _{1 in the} general formula (1) has a ring number of 4 or less.
(Claim 7)
7. The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is a multi-branched structure compound having the repeating unit represented by the general formula (1) in the second to fifth generations. .
(Claim 8)
The organic electroluminescence element according to claim 1, which emits white light.
(Claim 9)
A display device comprising the organic electroluminescence element according to claim 1.
(Claim 10)
The illuminating device provided with the organic electroluminescent element of any one of Claims 1-8.
(Claim 11)
A display device comprising: the lighting device according to claim 10; and a liquid crystal element as a display unit.

  Hereinafter, the present invention will be described in more detail.

  As a result of intensive studies, the inventors of the present invention have an organic electroluminescence device having at least one organic layer between a cathode and an anode, and the core compound is a luminescent compound in at least one layer of the organic layer. At least one moiety selected from a boron derivative, a silole derivative, a phenanthroline derivative, an azacarbazole derivative, a styryl derivative, and a fluorine-substituted triarylamine derivative having at least the second generation or more of the repeating unit represented by the general formula (1) It has been found that by including a multi-branched structure compound having a structure in the molecule, an organic electroluminescence device having high luminous efficiency and a long lifetime can be obtained.

  The multi-branched structure compound is different from a linear polymer extending in a one-dimensional direction or a so-called pendant (graft-type) polymer having a partially branched structure, and an arylene having a trivalent bond in the core compound or A compound in which a heteroarylene group is bonded via a linking group to form a planar or three-dimensional structure centering on a core compound. In the multi-branched structure compound of the present invention, the core compound is a luminescent compound and has at least the second generation or more of the repeating unit represented by the general formula (1), and includes boron derivatives, silole derivatives, phenanthroline derivatives, aza A compound having in the molecule thereof at least one partial structure selected from a carbazole derivative, a styryl derivative, and a fluorine-substituted triarylamine derivative. In the present invention, the use of the multi-branched structure compound having such a structure prevents the luminescent compounds from approaching each other in the organic layer, so that the luminescent compounds are substantially dispersed and exist. Thus, the effect of suppressing the concentration quenching can be obtained, and the light emission efficiency and the light emission lifetime can be improved. Furthermore, the holes and electrons are more efficiently transported to the light emitting compound as the core compound, and the light emission efficiency can be improved.

  In the present specification, a group having a linking group linked to a light-emitting compound to be a core compound and an arylene or heteroarylene group bonded to the linking group is defined as a first generation, and further to a first generation arylene or heteroarylene group. The second generation includes a linking group to be linked and an arylene or heteroarylene group bonded to the linking group. Hereinafter, the nth generation includes a linking group linked to the (n-1) generation arylene or heteroarylene group and an arylene or heteroarylene group bonded to the linking group.

  Therefore, in the present invention, the multi-branched structure compound having the repeating unit represented by the general formula (1) in at least the second generation or more is the repeating unit represented by the general formula (1) up to the second generation or more. It is a multi-branched structure compound that is formed.

  The core compound is a compound that becomes the central core of the multi-branched structure compound. In the present invention, the luminescent compound used for the core compound may be any compound as long as it emits light, but it is particularly preferable to use a fluorescent compound as the luminescent compound. Thereby, it can have higher luminous efficiency.

  The fluorescent compound is a compound having a partial structure of a fluorescent organic molecule having a high fluorescence quantum yield in a solution state or a rare earth complex phosphor. Here, the fluorescence quantum yield is preferably 10% or more, particularly preferably 30% or more. Examples of fluorescent organic molecules having a high fluorescence quantum yield include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and the like, and compounds having these partial structures can be used.

  Although the example of a fluorescent compound is shown below, the aspect of this invention is not limited by this.

  The examples of the fluorescent compounds each have a bond at a bondable position to form a multi-branched structure compound.

  Furthermore, in the present invention, it is particularly preferable to use a phosphorescent compound as the luminescent compound used for the core compound of the multi-branched structure compound. Thereby, it can have higher luminous efficiency.

  The phosphorescent compound is a compound having a partial structure in which light emission from an excited triplet is observed, and the phosphorescence quantum yield of the compound is 0.001 or more at 25 ° C. The phosphorescence quantum yield is preferably 0.01 or more, more preferably 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence quantum yield should just be achieved in any solvent.

  The phosphorescent compound is preferably an organometallic complex, which can further improve the light emission efficiency.

  The organometallic complex preferably has a partial structure represented by any one of the general formulas (2) to (5), and can thereby have even higher luminous efficiency.

In the general formula (2), R _{35 to} R ₄₂ each independently represents a hydrogen atom, a bond, or a substituent, and R _{35 to} R ₄₂ are bonded to each other to form a ring. Also good. M ₁ represents a metal atom.

In the general formula (3), Z ₁ and Z ₂ each independently represents an atomic group necessary for forming an aromatic ring together with a carbon atom and a nitrogen atom. M ₂ represents a metal atom.

In the general formula (4), R _{43 to} R ₄₈ each independently represent a hydrogen atom, a bond, or a substituent, and R _{43 to} R ₄₈ are bonded together to form a ring. Also good. M ₃ represents a metal atom.

In General Formula (5), Y represents a divalent linking group, R _{49 to} R ₅₆ each independently represent a hydrogen atom, a bond, or a substituent, and groups adjacent to R _{49 to} R ₅₆ May be combined with each other to form a ring. M ₄ represents a metal atom.

M ₁ , M ₂ , M ₃ , and M ₄ are preferably an iridium atom, a palladium atom, a platinum atom, a rhodium atom, a ruthenium atom, or an osmium atom. Thereby, it can have higher luminous efficiency.

  The organometallic complex according to the present invention is preferably an organometallic complex containing a group 8 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), A rhodium compound, a palladium compound, a ruthenium compound, and a rare earth complex, and an iridium compound is most preferable among them. Thereby, it can have higher luminous efficiency.

  Although the example of the partial structure of a phosphorescent compound is shown below (any part of these partial structures becomes a bond), the aspect of this invention is not limited by this.

  Moreover, although the example of a phosphorescent compound is shown below, the aspect of this invention is not limited by this.

  The examples of the phosphorescent compounds each have a bond at a bondable position to form a multi-branched structure compound.

In the general formula (1), Ar ₁ represents an arylene group or heteroarylene group which may have a substituent. L ₁ represents any linking group selected from the linking group group 1 described above.

In the linking group group 1, R _{1 to} R ₆ each independently represents an alkyl group or an aryl group, and R ₄ and R ₅ , or R ₆ and R ₇ may be linked to each other to form a ring.

Among the linking group group 1, —CH ₂ — or a linking group linked by an O atom, S atom, Se atom, or Si atom is particularly preferable for obtaining the effects of the present invention, and most preferably —CH ₂ — or They are linked by O atoms.

  Although the example of the said coupling group group 1 is shown below, the aspect of this invention is not limited by this.

Ar _{1 in the} general formula (1) preferably has a ring number of 4 or less, and can thereby have higher luminous efficiency.

Shows the example of Ar ₁ in the general formula (1) below, do not aspect of the present invention is not limited thereto.

The above examples of Ar ₁ each have a bond at a bondable position.

  In the present invention, the number of rings refers to one aromatic ring and one heteroaromatic ring, and the number of arylene groups and heteroarylene groups composed of n aromatic rings and heteroaromatic rings is n. In the case of a condensed ring, the number of condensed rings is indicated, and the number of condensed rings composed of n rings is n. For example, taking Chemical Example 10 as an example, 2, 10, 19, and 23-25 have 2 rings, and 3-5, 11, 12, 21, 26, and 28-30 have 3 rings. 6-9, 13-18, and 27 have 4 rings.

  The multi-branch structure compound according to the present invention is a multi-branch structure compound having the repeating unit represented by the general formula (1) in at least the second generation or more, preferably represented by the general formula (1). It is a multi-branched structure compound having repeating units in the second generation to the fifth generation. Particularly preferred is a multi-branched structure compound having the second to fourth generation repeating units represented by the general formula (1). By using such a multi-branched structure compound, the light emission efficiency and the light emission lifetime can be further improved.

  The multi-branched structure compound according to the present invention is a compound having in its molecule at least one partial structure selected from a boron derivative, a silole derivative, a phenanthroline derivative, an azacarbazole derivative, a styryl derivative, and a fluorine-substituted triarylamine derivative. Thus, the hole and electron are efficiently transported to the light emitting compound, and the light emission efficiency is improved. Particularly preferred are compounds having in the molecule at least one partial structure selected from boron derivatives, azacarbazole derivatives, and fluorine-substituted triarylamine derivatives. Thereby, holes and electrons are more efficiently transported to the light-emitting compound that is the core compound, and the light emission efficiency can be further improved.

  Examples of partial structures of boron derivatives, silole derivatives, phenanthroline derivatives, azacarbazole derivatives, styryl derivatives, and fluorine-substituted triarylamine derivatives are shown below (any part of these structural formulas is a bond). The embodiments of the invention are not limited thereby.

  Moreover, although the example of the multi-branch structure compound which concerns on this invention is shown below, the aspect of this invention is not limited by this.

  The multi-branched structure compound according to the present invention may be contained in any organic layer between the cathode and the anode, but is preferably contained in the light emitting layer. Thereby, it can have higher luminous efficiency.

  In this specification, the substituent is an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc. ), Cycloalkyl groups (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl groups (for example, vinyl group, allyl group, etc.), alkynyl groups (for example, ethynyl group, propargyl group, etc.), and aryls having heteroatoms Groups (eg, phenyl, naphthyl, pyridyl, thienyl, furyl, imidazolyl, etc.), heterocyclic groups (eg, pyrrolidyl, imidazolidyl, morpholyl, oxazolidyl, etc.), alkoxy groups (eg, methoxy Group, ethoxy group, propyloxy group, pentyloxy Groups, hexyloxy groups, octyloxy groups, dodecyloxy groups, etc.), cycloalkoxy groups (eg, cyclopentyloxy groups, cyclohexyloxy groups, etc.), aryloxy groups including those having heteroatoms (eg, phenoxy groups, naphthyloxy groups) Group, pyridyloxy group, thienyloxy group, etc.), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, Cyclohexylthio group, etc.), arylthio groups including those having heteroatoms (eg, phenylthio group, naphthylthio group, pyridylthio group, thienylthio group, etc.), alkoxycarbonyl groups (eg, methyloxycarbonyl group, ethyl) Oxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl groups including those having hetero atoms (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group, pyridyloxycarbonyl group, Thienyloxycarbonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2- Pyridylamino group, etc.), fluorine atom, chlorine atom, fluorinated hydrocarbon group (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), and cyano group. A plurality of these substituents may be bonded to each other to form a ring, or may be further substituted with the above substituents.

  The molecular weight of the multi-branched structure compound according to the present invention is preferably 1000 to 100,000, and more preferably 2000 to 50,000. By setting it within this range, when forming an organic layer of an organic EL element by a coating method, solubility in a solvent is ensured, and the viscosity of the solution is suitable for forming an organic layer, so that the organic layer is easily formed. can do.

  The multi-branched structure compound according to the present invention may be contained in any layer of the organic layer, but is preferably contained in the light emitting layer. Thereby, luminous efficiency can be improved.

  As for the multi-branched structure compound according to the present invention, a synthesis method is shown below for typical examples, but the embodiment of the present invention is not limited thereto.

Synthesis Example 1 (HB-1)
Chlorobis (1,3,5-trimethylphenyl) borane (3.4 g, 12 mmol) was dissolved in anhydrous THF (50 ml), and the reaction vessel was purged with nitrogen and cooled to 0 ° C. Separately, a THF solution of a lithiated product prepared from 1.7 g (10 mmol) of 4-bromophenol and 14 ml (1.6 M, 22 mmol) of n-butyllithium / n-hexane solution in anhydrous THF (15 ml) was prepared. It was dripped slowly. After stirring for 1 hour, the reaction solution was slowly returned to room temperature, and 20 ml of distilled water was added to stop the reaction. After separating the organic layer, the aqueous layer was extracted with THF and dried over anhydrous sodium sulfate. After the solvent was distilled off under reduced pressure, separation and purification were performed by silica gel chromatography (eluent: hexane / toluene = 50/50) to obtain Precursor 1 with a yield of 70% (2.4 g). Next, 0.4 g (1.8 mmol) of a boronic acid reagent separately prepared according to a conventional method from 3,5-dibromoanisole, 1.4 g (4.0 mmol) of precursor 1 and 0.7 g of copper (II) acetate (4 0.0 mmol), and 1 g of 0.4 nm molecular sieves in 100 ml of methylene chloride and with further stirring 1.0 g (10 mmol) of triethylamine was added. After 24 hours of reaction at room temperature, 5 ml of 2N hydrochloric acid was added, extracted with toluene, and the organic layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure and dried under reduced pressure. Under a nitrogen atmosphere, the reaction mixture was dissolved in 20 ml of methylene chloride and cooled to -78 ° C. A 1N boron bromide / methylene chloride solution (5.0 ml) was added dropwise thereto, and the mixture was further stirred at −25 ° C. for 2 hours. The reaction solution was slowly returned to room temperature, and 20 ml of distilled water was added to stop the reaction. After separating the organic layer, the aqueous layer was extracted with THF and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and separation and purification were performed using a column (eluent: HFIP) packed with Sephadex-G25 (manufactured by Aldrich). Precursor 2 was obtained in 61% yield (0.8 g) from the first fraction. Under a nitrogen stream, 0.5 g (0.8 mmol) of Precursor 2 and 0.16 g (0.33 mmol) of dibromo-N, N′-dimethylquinacridone were dissolved in 20 ml of dimethylacetamide, and 0.8 g (6.0 mmol) of potassium carbonate. ) Was added and heating under reflux was carried out for 40 hours. After completion of the reaction, extraction was performed by adding 150 ml of distilled water and 50 ml of THF. After drying the organic layer with anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and separation and purification were performed using a column (eluent: HFIP) packed with Sephadex-G25 (Aldrich). The desired HB-1 was obtained from the first fraction in a yield of 21% (0.13 g).

Synthesis example 2 (HB-5)
3.9 g (5.0 mmol) of the foregoing precursor 2 and 0.8 g (2.0 mmol) of 3- (2-pyridyl) phenylboronic acid, 0.9 g (5.0 mmol) of copper (II) acetate, and 1 g of 0.4 nm molecular sieves were added to 100 ml of methylene chloride, and 5.0 g (50 mmol) of triethylamine was added with further stirring. After 24 hours of reaction at room temperature, 15 ml of 2N hydrochloric acid was added, extracted with toluene, and the organic layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and separation and purification were performed using a column (eluent: HFIP) packed with Sephadex-G25 (manufactured by Aldrich). Precursor 3 was obtained from the first fraction in a yield of 80% (1.5 g). Furthermore, 25 ml of glycerol was placed in the reaction vessel and stirred at 140 ° C. for 2 hours while bubbling nitrogen. After stopping heating and allowing to cool to 100 ° C., 1.4 g (1.5 mmol) of Precursor 3 and 0.12 g (0.25 mmol) of iridium (III) acetylacetonate were added, and at 220 ° C. under a nitrogen stream. The reaction was performed for 8 hours. After cooling to room temperature, 100 ml of 1N-hydrochloric acid was added, the precipitate was filtered and washed with water, dissolved in HFIP, and insolubles were removed by filtration. This solution was separated and purified using a column (eluent: HFIP) packed with Sephadex-G25 (Aldrich). The target Ir complex (HB-5) could be obtained in a yield of 29% (0.22 g) from the first fraction.
Further, an Ir complex (HB-7) could be obtained from the precursor 3 in a yield of 15% (0.17 g) in the same manner as in the precursor 2 and HB-5 synthesis method.

Synthesis Example 3 (HB-13)
6.2 g (20 mmol) of 1,3,5-tribromobenzene and 7.4 g (40 mmol) of 4,4′-biphenol were dissolved in 20 ml of toluene, and 10 mL of 6 M aqueous sodium hydroxide solution was vigorously stirred. added. After stirring vigorously as it was for about 1 minute, 0.047 g (0.14 mmol) of tetrabutylammonium hydrosulfate was added, and the reaction was carried out at room temperature for 5 hours. Subsequently, 3.4 g (20 mmol) of 2- (3-hydroxyphenyl) pyridine was added and further reacted at room temperature for 5 hours. After elapse of a predetermined time, the organic layer was separated, and this organic layer was washed with distilled water, and then the organic layer was separated again and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and purification was performed by silica gel chromatography (eluent: hexane / toluene = 1/1) to obtain Precursor 4 in a yield of 71% (8.8 g). Next, 2.0 g (10 mmol) of 2-methyl-8-quinolinol and 2.0 g (10 mmol) of aluminum isopropoxide were added to 100 ml of anhydrous toluene, and the mixture was heated and stirred. Next, 2.0 g (10 mmol) of 2-methyl-8-quinolinol and 3.1 g (5 mmol) of the aforementioned precursor 4 were dissolved in 100 ml of anhydrous toluene, and this was added to the reaction solution. The mixture was heated to reflux for 6 hours, cooled to room temperature, and the precipitate was filtered off. This solid was washed with ethanol and then dried under reduced pressure to obtain 62% (4.3 g) of precursor 5. Furthermore, 25 ml of glycerol was placed in the reaction vessel and stirred at 140 ° C. for 2 hours while bubbling nitrogen. After stopping the heating and allowing to cool to 100 ° C., 3.9 g (3.0 mmol) of the precursor 6 and 0.24 g (0.5 mmol) of iridium (III) acetylacetonate were added and reacted at 220 ° C. for 8 hours under a nitrogen stream. Went. After cooling to room temperature, 150 ml of 1N-hydrochloric acid was added, the precipitate was filtered and washed with water, dissolved in HFIP, and insoluble matter was removed by filtration. This solution was separated and purified using a column (eluent: HFIP) packed with Sephadex-G25 (Aldrich). The desired Ir complex (HB-13) could be obtained in a yield of 9% (0.18 g) from the first fraction.

Synthesis Example 4 (HB-10)
Under a nitrogen stream, 3.4 g (15 mmol) of 1,3,5-trischloromethylbenzene was dissolved in 100 ml of THF and cooled to −25 ° C. A lithium reagent prepared from 10.7 g (33 mmol) of 4-bromophenylazacarbazole according to a conventional method was slowly added dropwise thereto and further stirred at −25 ° C. for 2 hours. The reaction solution was slowly returned to room temperature, and 50 ml of distilled water was added to stop the reaction. After separating the organic layer, the aqueous layer was extracted with THF and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and separation and purification were performed by silica gel chromatography (eluent: hexane / toluene = 70/30) to obtain the precursor 6 in a yield of 76% (7.3 g).

  Similarly, after reacting a precursor 6 with a lithium reagent prepared from 3- (2-pyridyl) bromobenzene, separation and purification are performed by silica gel chromatography (eluent: hexane / THF = 80/20). Body 7 was obtained in a yield of 73% (5.5 g). Furthermore, 25 ml of glycerol was placed in the reaction vessel and stirred at 140 ° C. for 2 hours while bubbling nitrogen. After stopping the heating and allowing to cool to 100 ° C., 72.3 g (3.0 mmol) of the precursor and 0.24 g (0.5 mmol) of iridium (III) acetylacetonate were added, and the reaction was carried out at 220 ° C. for 118 h under a nitrogen stream. went. After cooling to room temperature, 150 ml of 1N-hydrochloric acid was added, the precipitate was filtered and washed with water, dissolved in HFIP, and insoluble matter was removed by filtration. This solution was separated and purified using a column (eluent: HFIP) packed with Sephadex-G25 (Aldrich). The desired Ir complex (HB-10) was obtained from the first fraction in a yield of 15% (0.18 g).

  Moreover, the multibranched compounds of the present invention other than those described above can be synthesized by appropriately applying these synthesis methods described above.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described.

In this invention, although the preferable specific example of the organic layer structure of an organic EL element is shown below, this invention is not limited to these.
(1) Anode / light emitting layer / cathode (2) Anode / light emitting layer / cathode buffer layer / cathode (3) Anode / anode buffer layer / light emitting layer / cathode buffer layer / cathode (4) Anode / hole transport layer / light emission Layer / cathode (5) anode / hole transport layer / light emitting layer / electron transport layer / cathode (6) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode (7) anode / positive Hole transport layer / electron blocking layer / light emitting layer / electron transport layer / cathode (8) anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode (9) anode / anode buffer Layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode << Anode >>
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, a thin film may be formed by depositing these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (100 μm or more) Degree), a pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. When light emission is extracted from the anode, it is desirable that the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this, such as a magnesium / silver mixture, magnesium, from the viewpoint of electron injectability and durability against oxidation, etc. / Aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 1000 nm, preferably 50 nm to 200 nm. In order to transmit light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

<< Buffer layer: cathode buffer layer, anode buffer layer >>
The buffer layer is provided as necessary, and includes a cathode buffer layer and an anode buffer layer, and is present between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer as described above. May be.

  The buffer layer is a layer that is provided between the electrode and the organic layer in order to lower the drive voltage and improve the light emission luminance. “The organic EL element and the forefront of its industrialization (November 30, 1998, issued by NTT Corporation) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer are also described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, a phthalocyanine buffer layer represented by copper phthalocyanine And an oxide buffer layer typified by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene. Among these, those using polydioxythiophenes are preferable, and thereby, an organic EL device that exhibits higher light emission luminance and light emission efficiency and has a longer lifetime can be obtained.

  The details of the cathode buffer layer are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, specifically, metals represented by strontium, aluminum and the like. Examples thereof include a buffer layer, an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, and an oxide buffer layer typified by aluminum oxide.

  The buffer layer is preferably a very thin film, and depending on the material, the film thickness is preferably in the range of 0.1 nm to 100 nm.

  As described above, the blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL element and its forefront of industrialization” (issued on November 30, 1998 by NTS Corporation). There is a hole blocking layer.

  The cathode buffer layer and the anode buffer layer can be formed by thinning the above materials by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method.

<Blocking layer: hole blocking layer, electron blocking layer>
The hole blocking layer is an electron transport layer in a broad sense, and is made of a material that has a function of transporting electrons and has a very small ability to transport holes. By blocking holes while transporting electrons, And the recombination probability of holes can be improved.

  The hole blocking layer has a role of blocking the holes moving from the hole transport layer from reaching the cathode and a compound that can efficiently transport the electrons injected from the cathode toward the light emitting layer. It is formed. The physical properties required of the material constituting the hole blocking layer are higher than the ionization potential of the light emitting layer in order to have high electron mobility and low hole mobility and to efficiently confine holes in the light emitting layer. It is preferable to have a value of ionization potential or a band gap larger than that of the light emitting layer. Use of at least one of styryl compounds, triazole derivatives, phenanthroline derivatives, oxadiazole derivatives, and boron derivatives as the hole blocking material is also effective in obtaining the effects of the present invention.

  Examples of other compounds include exemplified compounds described in JP-A Nos. 2003-31367, 2003-31368, and Japanese Patent No. 2721441.

  On the other hand, the electron blocking layer is a hole transport layer in a broad sense, made of a material that has a function of transporting holes and has a very small ability to transport electrons, and blocks electrons while transporting holes. Thus, the probability of recombination of electrons and holes can be improved.

  The hole blocking layer and the electron blocking layer can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method. .

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from an electrode, an electron transport layer, a hole transport layer, or the like, and the light emitting portion is in the layer of the light emitting layer. Alternatively, it may be the interface between the light emitting layer and the adjacent layer.

  As the light-emitting compound used in the light-emitting layer, the above-described multi-branched structure compound according to the present invention can be used. Thereby, luminous efficiency and luminous lifetime can be improved.

  In addition to the multi-branched structure compound according to the present invention, a conventionally known fluorescent compound or phosphorescent compound can also be used as the luminescent compound used in the light emitting layer.

  There are two types of light emission of phosphorescent compounds in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is phosphorescent. Energy transfer type to obtain light emission from the phosphorescent compound by transferring to the compound, the other is that the phosphorescent compound becomes a carrier trap, carrier recombination occurs on the phosphorescent compound, and from the phosphorescent compound In any case, the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  In addition, it is also preferable to use a complex compound containing a group 8 metal in the periodic table of elements as the phosphorescent compound, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex system). Compound), a rhodium compound, a palladium compound, and a rare earth complex, and most preferred is an iridium compound.

  Although the specific example of the phosphorescent compound of a complex type compound is shown below, it is not limited to these. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

  In addition, the light emitting layer may contain a host compound.

  In the present invention, the host compound is a compound having a phosphorescence quantum yield of phosphorescence emission of less than 0.01 at room temperature (25 ° C.) among compounds contained in the light emitting layer.

  As the host compound, a known host compound can be used, and a plurality of known host compounds may be used in combination. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient.

  As these known host compounds, compounds having a hole transporting ability and an electron transporting ability, preventing the emission of longer wavelengths, and having a high Tg (glass transition temperature) are preferable.

  Specific examples of known host compounds include compounds described in the following documents.

  JP 2001-257076, JP 2002-308855, JP 2001-313179, JP 2002-319491, JP 2001-357777, JP 2002-334786, JP 2002-8860, JP 2002-334787, JP 2002-15871, JP2002-334788, JP2002-43056, JP2002-334789, JP2002-756645, JP2002-338579, JP2002-105445, JP2002-343568, JP2002 141173, JP2002-352957, JP2002203683, JP2002-363227, JP2002-231453, JP2003-3165, JP2002-234888, JP2003-27048, JP200. -255934, JP 2002-260861, JP 2002-280183, JP 2002-299060, JP 2002-302516, JP 2002-305083, JP 2002-305084, 2002-308837, etc. JP.

  Moreover, the light emitting layer may contain the host compound which has a fluorescence maximum wavelength further as a host compound. In this case, the energy transfer from the other host compound and the phosphorescent compound to the fluorescent compound allows electroluminescence as an organic EL element to be emitted from the other host compound having a fluorescence maximum wavelength. A host compound having a fluorescence maximum wavelength is preferably a compound having a high fluorescence quantum yield in a solution state. Here, the fluorescence quantum yield is preferably 10% or more, particularly preferably 30% or more. Specific host compounds having a maximum fluorescence wavelength include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Perylene dyes, stilbene dyes, polythiophene dyes, and the like. The fluorescence quantum yield can be measured by the method described in 362 (1992, Maruzen) of Spectroscopic II of the Fourth Edition Experimental Chemistry Course 7.

  The color emitted in this specification is the spectral radiance meter CS-1000 (Minolta) in FIG. 4.16 on page 108 of “New Color Science Handbook” (Edited by the Japan Society for Color Science, University of Tokyo Press, 1985). It is determined by the color when the measured result is applied to the CIE chromaticity coordinates.

  In the present invention, as the light emitting material of the light emitting layer, it is particularly preferable to use a multi-branched structure compound according to the present invention and a multi-branched structure compound using a phosphorescent compound as a core compound. Thereby, the luminous efficiency can be further improved.

  In addition, when the above-described multi-branched structure compound is used as the light emitting material, it is preferable that the phosphorescent compound has a phosphorescent maximum wavelength of 380 to 480 nm. As what has such a phosphorescence emission wavelength, the organic EL element which light-emits blue and the organic EL element which light-emits white are mentioned. Furthermore, arbitrary luminescent color can be obtained by using multiple types of the multi-branch structure compound based on this invention which used the phosphorescent compound from which a phosphorescence emission wavelength differs as a core compound for a light emitting layer. White light emission is possible by adjusting the kind of phosphorescent compound used for the core compound and the amount of the multi-branched structure compound, and can also be applied to illumination and backlight.

  In particular, an organic EL element that emits white light has a light emitting compound (for example, blue, green, and red) having a difference in energy level in the light emitting layer, so that red having a low energy level easily emits light. Since green and blue light emission is reduced, conventionally, a large amount of green or blue light-emitting compound is added to red to increase the green and blue light emission and solve the problem. However, since the concentration quenching occurs when the concentration of the three color luminescent compounds in the luminescent layer exceeds a certain level, the total concentration of the three color luminescent compounds has an upper limit. Therefore, since the white light emission efficiency matched to the light emission of the red light emitting compound having a low concentration of the light emitting compound due to the mixing ratio, it has been difficult to improve the white light emission efficiency conventionally.

  However, by using a multi-branched structure compound having a light-emitting compound as the core compound of the present invention, concentration quenching in the light-emitting layer can be suppressed, so that each color can be added at a high concentration, and white light emission can be achieved. Can be improved. In addition, since blue, green, and red luminescent compounds are unlikely to be close to each other in the light emitting layer, it is not necessary to add a large amount of green or blue luminescent compounds to red as in the prior art.

  The light emitting layer can be formed by forming a film by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink jet method.

  The light emitting layer is preferably produced by a coating method containing the multi-branched structure compound according to the present invention. The multi-branched structure compound according to the present invention is particularly suitable for production by a spin coating method, a coating method such as an ink jet method, and the production can be facilitated by producing by these methods. Further, a large area organic EL element or a white light emitting organic EL element can be easily manufactured, which is preferable.

  Although the film thickness as a light emitting layer does not have a restriction | limiting in particular, Usually, 5 nm-5 micrometers, Preferably it is chosen in the range of 5 nm-200 nm.

《Hole transport layer》
The hole transport layer is made of a material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer and the electron transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material is not particularly limited, and is conventionally used as a hole charge injection / transport material in an optical transmission material or a well-known material used for a hole injection layer or a hole transport layer of an EL element. Any one can be selected and used.

  In the present invention, as the hole transport material, a polymer containing at least one repeating unit represented by the above general formula (2), wherein X is a hole transporting group, is used in the hole transport layer. It is also preferable to contain. Thereby, it has higher light emission luminance, light emission efficiency, and light emission lifetime, and can further reduce driving power.

  Other examples of hole transport materials include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, Examples include styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  As the hole transport material, those described above can be used, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N′-diphenyl-N, N ′ − (4-methoxyphenyl) -4,4′-diaminobiphenyl; N, N, N ′, N′-tetraphenyl-4,4′-diaminodiphenyl ether; 4,4′-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 ′-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 688 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  In the present invention, the hole transport material of the hole transport layer preferably has a fluorescence maximum wavelength at 415 nm or less. That is, the hole transport material is preferably a compound that has a hole transport ability, prevents the emission of light from becoming longer, and has a high Tg.

  This hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, it is about 5-5000 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, as an electron transport material used for an electron transport layer adjacent to the light emitting layer on the cathode side, from among known materials used for an electron transport layer Any one can be selected and used.

  In the present invention, as the electron transport material, a polymer containing at least one repeating unit represented by the above general formula (2), wherein X is an electron transporting group, is contained in the electron transport layer. Is also preferable. Thereby, it has higher light emission luminance, light emission efficiency, and light emission lifetime, and can further reduce driving power.

  In addition, examples of the electron transport material include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. These electron transport materials are preferably used as the above-described electron transporting portion because the effects of the present invention can be obtained.

  Further, the electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer, and any material can be selected from conventionally known compounds. .

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg, Cu Metal complexes replaced with Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transport material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and similarly to the hole injection layer and the hole transport layer, inorganic such as n-type-Si and n-type-SiC. A semiconductor can also be used as an electron transport material.

  It is preferable that the preferable compound used for an electron carrying layer has a fluorescence maximum wavelength in 415 nm or less. That is, the compound used for the electron transport layer is preferably a compound that has an electron transport ability, prevents emission of longer wavelengths, and has a high Tg.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, it is about 5-5000 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

<< Substrate (also referred to as substrate, substrate, support, etc.) >>
The substrate of the organic EL device of the present invention is not particularly limited to the type of glass, plastic, etc., and is not particularly limited as long as it is transparent. Examples of substrates that are preferably used include glass, quartz, A light transmissive resin film can be mentioned. A particularly preferable substrate is a resin film that can give flexibility to the organic EL element.

  Examples of the resin film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose. Examples include films made of triacetate (TAC), cellulose acetate propionate (CAP), and the like.

  An inorganic or organic coating or a hybrid coating of both may be formed on the surface of the resin film.

  The external extraction efficiency at room temperature of light emission of the organic electroluminescence device of the present invention is preferably 1% or more, more preferably 2% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  Further, a hue improving filter such as a color filter may be used in combination.

  The multicolor display device of the present invention comprises at least two kinds of organic EL elements having different light emission maximum wavelengths, and a preferred example for producing the organic EL elements will be described.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / anode buffer layer / hole transport layer / light emitting layer / electron transport layer / cathode buffer layer / cathode will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm. Make it. Next, an organic compound thin film of an anode buffer layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode buffer layer, which are element materials, is formed thereon.

As described above, there are spin coating methods, casting methods, ink jet methods, vapor deposition methods, printing methods and the like as methods for thinning the organic compound thin film, but it is easy to obtain a uniform film and it is difficult to generate pinholes. In view of the above, the vacuum deposition method or the spin coating method is particularly preferable. Further, different film forming methods may be applied for each layer. When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a vacuum degree of 10 ⁻⁶ Pa to 10 ⁻² Pa, a vapor deposition rate of 0. It is desirable to select appropriately within the range of 01 nm to 50 nm / second, substrate temperature −50 ° C. to 300 ° C., and film thickness 0.1 nm to 5 μm.

  After the formation of these layers, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  The display device of the present invention is provided with a shadow mask only at the time of forming a light emitting layer, and the other layers are common, so patterning such as a shadow mask is not necessary, and vapor deposition, casting, spin coating, ink jet, printing A layer can be formed by a method or the like.

  When patterning is performed only on the light-emitting layer, the method is not limited, but a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.

  Moreover, it is also possible to reverse the production order and produce the cathode, the cathode buffer layer, the electron transport layer, the light emitting layer, the hole transport layer, the anode buffer layer, and the anode in this order.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

  The display device of the present invention uses the organic EL element of the present invention and can be used as a display device, a display, or various light sources. In a display device or a display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  The lighting device of the present invention uses the organic EL element of the present invention, adjusts the phosphorescent compound of the organic EL element of the present invention to emit white light, and is used for home lighting, interior lighting, watch backlight, Examples include, but are not limited to, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, and light sources of optical sensors. It can also be used as a backlight for liquid crystal display devices and the like.

  Further, the organic EL element according to the present invention may be used as an organic EL element having a resonator structure.

  Examples of the purpose of use of the organic EL element having such a resonator structure include a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processing machine, and a light source of an optical sensor. It is not limited. Moreover, you may use for the said use by making a laser oscillation.

  As described above, the organic EL element of the present invention may be used as one kind of lamp for illumination or exposure light source, or a projection device for projecting an image, or directly viewing a still image or a moving image. It may be used as a type of display device (display). When used as a display device for reproducing moving images, the driving method may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using three or more organic EL elements of the present invention having different emission colors. Alternatively, it is possible to make one color emission color, for example, white emission, into BGR by using a color filter to achieve full color. Furthermore, it is possible to convert the emission color of the organic EL to another color by using a color conversion filter, and in this case, λmax of the organic EL emission is preferably 480 nm or less.

  An example of a display device composed of the organic EL element of the present invention will be described below based on the drawings.

  FIG. 1 is a schematic diagram illustrating an example of a display device including organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.

  The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of the plurality of pixels based on image information from the outside. The pixels for each scanning line are converted into image data signals by the scanning signal. In response to this, light is sequentially emitted and image scanning is performed to display image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below. FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions (details are shown in FIG. Not shown).

  When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data. Full color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region that emit light on the same substrate.

  Next, the light emission process of the pixel will be described.

  FIG. 3 is a schematic diagram of a pixel.

  The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10, and the power supply line 7 connects to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.

  When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 maintains the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.

  That is, the light emission of the organic EL element 10 is performed by providing the switching transistor 11 and the drive transistor 12 which are active elements with respect to the organic EL elements 10 of the plurality of pixels, respectively. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or on / off of a predetermined light emission amount by a binary image data signal. But you can.

  The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

  FIG. 4 is a schematic view of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.

  When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal. In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

  According to the present invention, it is possible to provide an organic electroluminescence element having a high light emission efficiency and a long light emission lifetime, and a display device or a lighting device including the same.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this.

Example 1
<Preparation of organic EL elements 1-1 to 1-6>
(1) Production of Organic EL Element 1-1 Patterning was performed on a substrate (NA45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes. This transparent support substrate is fixed to a substrate holder of a commercially available vacuum evaporation apparatus, while 200 mg of NPD is put into a molybdenum resistance heating boat, and 200 mg of CBP is put into another molybdenum resistance heating boat, and another molybdenum resistance heating boat is placed. 100 mg of Ir-1 was put in, 200 mg of bathocuproin (BCP) was put in another resistance heating boat made of molybdenum, and attached to a vacuum deposition apparatus.

Next, the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, and the heating boat containing NPD was heated by energization, and deposited on a transparent support substrate at a deposition rate of 0.1 nm / sec to form a 45 nm hole transport layer. Provided.

  Further, the heating boat containing CBP and Ir-1 was energized and heated, and co-evaporated on the hole transport layer at a deposition rate of 0.1 nm / sec and 0.006 nm / sec, respectively, to provide a 30 nm light emitting layer. It was.

Furthermore, the heating boat containing BCP was energized and heated, and was deposited on the light emitting layer at a deposition rate of 0.1 nm / sec to provide an electron transport layer having a thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Then, 0.5 nm of lithium fluoride was vapor-deposited as a cathode buffer layer, and also aluminum 110nm was vapor-deposited, the cathode was formed, and the organic EL element 1-1 was produced.

  The organic EL device 1 was prepared in the same manner as the organic EL device 1-1 except that the compounds used in the electron transport layer, the light emitting layer, and the hole transport layer of the organic EL device 1-1 were changed to those shown in Table 1. 2-1-6 were produced.

<Evaluation of organic EL elements 1-1 to 1-6>
The obtained organic EL elements 1-1 to 1-6 were evaluated as follows.

(External extraction quantum efficiency)
About the produced organic EL element, the external extraction quantum efficiency (%) when a ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Minolta) was used in the same manner.

(Luminescent life)
When driving at a constant current of ^2.5 mA / cm ^{2 in} a dry nitrogen gas atmosphere at 23 ° C., the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured. Was used as an index of life as half-life time (τ0.5). For the measurement, a spectral radiance meter CS-1000 (manufactured by Minolta) was used.

  The measurement results of the external extraction quantum efficiency and the light emission lifetime of the organic EL elements 1-1, 1-3, and 1-4 are shown in Table 2 as relative values when the organic EL element 1-1 is 100. The measurement results of the external extraction quantum efficiency and the light emission lifetime of the organic EL elements 1-2, 1-5, and 1-6 are shown in Table 3 as relative values when the organic EL element 1-2 is set to 100.

  As is clear from Tables 2 and 3, it was found that the organic EL device of the present invention has greatly improved luminous efficiency and luminous lifetime.

Example 2
<Preparation of organic EL elements 2-1 to 2-12>
After patterning on a substrate (NH-Techno Glass NA-45) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes. On this transparent support substrate, 30 mg of polyvinylcarbazole (PVK) and 1.8 mg of Ir-1 were dissolved in 1 ml of dichlorobenzene and spin-coated under conditions of 1000 rpm and 5 sec (film thickness of about 100 nm), and 1 at 60 degrees. It was vacuum-dried for a time to obtain a light emitting layer.

This was attached to a vacuum deposition apparatus, and then the vacuum chamber was decompressed to 4 × 10 ⁻⁴ Pa, and lithium fluoride 0.5 nm was deposited as a cathode buffer layer and aluminum 110 nm was deposited as a cathode to form a cathode. Finally, glass sealing was performed to prepare an organic EL element 2-1.

  Organic EL elements 2-2 to 2-12 are the same as organic EL element 2-1, except that PVK and Ir-1 used in the light emitting layer of organic EL element 2-1 are changed to those shown in Table 4. Was made.

<Evaluation of organic EL elements 2-1 to 2-12>
The same evaluation as Example 1 was performed about obtained organic EL element 2-1 to 2-12. The measurement results of the external extraction quantum efficiency and the light emission lifetime of the organic EL elements 2-1 and 2-3 to 2-9 are shown in Table 5 as relative values when the organic EL element 2-1 is 100. The measurement results of the external extraction quantum efficiency and the light emission lifetime of the organic EL elements 2-2 and 2-10 to 2-12 are shown in Table 6 as relative values when the organic EL element 2-2 is 100.

  As is clear from Tables 5 and 6, it was found that the organic EL device of the present invention has greatly improved luminous efficiency and luminous lifetime.

Example 3
<Full color display device>
(Blue light emitting organic EL device)
In the organic EL element 2-6 produced in Example 2, the organic EL element 2-6B produced by the method similar to the organic EL element 2-6 except having changed HB-8 used for the light emitting layer into HB-14 Was used.

(Green light-emitting organic EL device)
The organic EL element 2-6 produced in Example 2 was used.

(Red light emitting organic EL device)
In the organic EL element 2-6 produced in Example 2, the organic EL element 2-6R produced by the same method as the organic EL element 2-6 except that HB-8 used for the light emitting layer was changed to HB-15. Was used.

  The red, green and blue light emitting organic EL elements are juxtaposed on the same substrate to produce an active matrix type full color display device having the form shown in FIG. 1, and FIG. 2 shows a display of the produced display device. Only the schematic diagram of part A is shown. That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate, and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions ( Details are not shown). The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. Then, an image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, a full color display device was produced by appropriately juxtaposing the red, green, and blue pixels.

  It was confirmed that by driving the full-color display device, a full-color moving image display having a high light emission efficiency and a long light emission life can be obtained.

Example 4 (Example of lighting device, using white organic EL element)
In the organic EL element 2-6 produced in Example 2, it is the same as the organic EL element 2-6 except that HB-8 used for the light emitting layer was changed to a mixture of HB-8, HB-14, and HB-15. The organic EL element 2-10W produced by the method was used. The non-light-emitting surface of the organic EL element 2-6W was covered with a glass case to obtain a lighting device. The illuminating device could be used as a thin illuminating device that emits white light with high luminous efficiency and long emission life. FIG. 5 is a schematic view of the lighting device, and FIG. 6 is a cross-sectional view of the lighting device. The organic EL element 101 is covered with a glass cover 102 and connected with a power line (anode) 103 and a power line (cathode) 104. 105 is a cathode and 106 is an organic EL layer. The glass cover 102 is filled with nitrogen gas 108 and a water replenisher 109 is provided.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full-color display device. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 102 Glass cover 103 Power supply line (anode)
104 Power line (cathode)
105 Cathode 106 Organic EL layer 107 Glass substrate with transparent electrode 108 Nitrogen gas 109 Water trapping agent

Claims (11)

An organic electroluminescent device having at least one organic layer between a cathode and an anode, wherein the core compound is a luminescent compound in at least one layer of the organic layer and is represented by the following general formula (1) Multi-branched structure compound having at least a second generation unit and having in its molecule at least one partial structure selected from boron derivatives, silole derivatives, phenanthroline derivatives, azacarbazole derivatives, styryl derivatives, and fluorine-substituted triarylamine derivatives An organic electroluminescence device comprising:

[In the formula, Ar ₁ represents an arylene group or a heteroarylene group which may have a substituent. L ₁ represents any linking group selected from the following linking group group 1. ]

[R _{1 to} R ₆ each independently represents an alkyl group or an aryl group, and R ₃ and R ₄ , or R ₅ and R ₆ may be linked to each other to form a ring. ] The organic electroluminescence device according to claim 1, wherein the light emitting compound is a fluorescent compound. The organic electroluminescence device according to claim 1, wherein the light emitting compound is a phosphorescent compound. The organic electroluminescent device according to claim 3, wherein the phosphorescent compound is an organometallic complex. The organic electroluminescence device according to claim 4, wherein the organometallic complex has a partial structure represented by any one of the following general formulas (2) to (5).

[In General Formula (2), R _{35 to} R ₄₂ each independently represents a hydrogen atom, a bond, or a substituent, and R _{35 to} R ₄₂ are adjacent to each other to form a ring. May be. M ₁ represents a metal atom.
In the general formula (3), Z ₁ and Z ₂ each independently represents an atomic group necessary for forming an aromatic ring together with a carbon atom and a nitrogen atom. M ₂ represents a metal atom.
In the general formula (4), R _{43 to} R ₄₈ each independently represent a hydrogen atom, a bond, or a substituent, and R _{43 to} R ₄₈ are bonded together to form a ring. Also good. M ₃ represents a metal atom.
In General Formula (5), Y represents a divalent linking group, R _{49 to} R ₅₆ each independently represent a hydrogen atom, a bond, or a substituent, and groups adjacent to R _{49 to} R ₅₆ May be combined with each other to form a ring. M ₄ represents a metal atom. ] The organic electroluminescence device according to claim 1, wherein Ar _{1 in the} general formula (1) has a ring number of 4 or less. 7. The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is a multi-branched structure compound having the repeating unit represented by the general formula (1) in the second to fifth generations. . The organic electroluminescence element according to claim 1, which emits white light. A display device comprising the organic electroluminescence element according to claim 1. The illuminating device provided with the organic electroluminescent element of any one of Claims 1-8. A display device comprising: the lighting device according to claim 10; and a liquid crystal element as a display unit.

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