JP2005063938A - Organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element having good light emitting characteristics and durability. <P>SOLUTION: The organic electroluminescent element has at least one organic layer including a light emitting layer between a pair of electrodes. The light emitting layer contains at least one kind of metal complex having a glass transition temperature (Tg) of 140°C or more (A), a condensed aromatic compound having Tg of 140°C or more (B), and a light emitting material (C). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic electroluminescent element capable of emitting light by converting electric energy into light.

  Today, research and development on various display elements are active. Among them, organic electroluminescence (EL) elements are attracting attention as promising display elements because they can emit light with high luminance at a low voltage. In recent years, research on high durability of organic EL elements has been actively conducted for practical use of full-color displays, and various kinds of hole injection materials, hole transport materials, light emitting materials, host materials, electron transport materials, and electron injection materials have been studied. The structure of

  An example in which a metal complex composed of a nitrogen-containing ligand, a nitrogen-containing heterocyclic compound, an electron-transporting compound that is a Si-containing ring compound, and an anthryl compound are mixed as a host is disclosed (for example, Patent Document 1). It is disclosed that a two-component compound is mixed as in a case where a non-polar organic compound capable of transporting both electrons and holes and an organic compound having a higher polarity than the component are mixed as a host (for example, Patent Document 2). An organic electroluminescent element containing a metal complex and a condensed ring compound is disclosed (for example, Patent Document 3). Improvements are desired for further color purity, durability, luminance and efficiency.

JP 2001-284050 A European Patent Application No. 1221473A1 JP 2001-192651 A

  An object of the present invention is to provide a light emitting element having good light emitting characteristics and durability.

As a result of studying the above problems, the present inventors have reached the present invention by the following means.
1. An organic electroluminescent element having at least one organic layer including a light emitting layer between a pair of electrodes, wherein the light emitting layer has at least one kind of a metal complex (A) having a glass transition temperature (Tg) of 140 ° C. or higher as a host. An organic electroluminescent device comprising: at least one condensed aromatic compound (B) having a thermal decomposition starting temperature of 330 ° C. or higher; and at least one light emitting material (C).
2. 2. The organic electroluminescent device according to 1, wherein the condensed aromatic compound (B) has at least two condensed aromatic carbocycles having 3 or more rings. However, when three condensed aromatic carbocycles are connected to each other, the molecule further contains at least two four or more condensed rings.
3. The organic electroluminescent device according to 1, wherein the condensed aromatic compound contains at least two condensed aromatic heterocycles having three or more rings, provided that when three condensed aromatic carbocycles are linked to each other, The molecule further contains at least one fused ring of 4 or more rings.
4). 2. The organic electroluminescent element according to 1, wherein the condensed aromatic compound (B) is represented by the following general formula (1).

In the formula, Ar represents a polyvalent aromatic ring group, Ar ¹¹ , Ar ²¹ and Ar ³¹ represent an arylene group, and Ar ¹² , Ar ²² and Ar ³² represent a substituent or a hydrogen atom. At least two of Ar ¹¹ , Ar ²¹ , Ar ³¹ , Ar ¹² , Ar ²² , Ar ³² are three or more condensed aromatic carbocyclic rings or condensed aromatic heterocyclic rings.
5). The metal complex (A) is a metal complex having a ligand having at least one nitrogen atom, oxygen atom, or sulfur atom coordinated to a metal, according to any one of 1 to 4, Organic electroluminescent element.
6). The organic electroluminescent element according to any one of 1 to 5, wherein the metal complex is represented by the following general formula (9) or general formula (10).

In the formula, M ¹¹ is a metal ion, L ¹¹ is a ligand, X ¹¹ is an oxygen atom, a substituted or unsubstituted nitrogen atom (substituents on the nitrogen atom include —SO ₂ R ^a , —COR ^b or — P (= O) (R ^c ) (R ^d ) (R ^a , R ^b , R ^c , R ^d are each an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, or Q ¹¹ represents an atomic group that forms an aromatic ring, Q ¹² represents an atomic group that forms a nitrogen-containing aromatic ring, and Q ¹¹ and Q ¹² are bonded to each other. The ring formed by Q ¹¹ or Q ¹² may have a substituent, and m ¹¹ and m ¹² are each an integer of 0 to 3 and an integer of 1 to 4. Represent.

In the general formula (10), L ²¹ and X ²¹ have the same meanings as L ¹¹ and X ¹¹ , and m ²¹ and m ²² represent an integer of 0 to 3 and an integer of 1 to 4, respectively. M ²¹ represents a metal ion. Q ²¹ represents an atomic group forming an aromatic ring. Q ²² represents an atomic group forming a nitrogen-containing aromatic ring. Q ²¹ and Q ²² may be bonded to form a condensed ring structure. The ring formed by Q ²¹ or Q ²² may have a substituent.
7). The organic electroluminescent element according to any one of 1 to 6, wherein the luminescent material is a fluorescent compound.
8). The organic electroluminescent element according to any one of 1 to 7, wherein the luminescent material is a phosphorescent compound.
9. 8. The organic electroluminescent device according to 7, wherein the fluorescent compound is a compound selected from a styryl compound, a condensed aromatic compound, a pyromethene complex compound, a diketopyrrolopyrrole compound, and an oxazine compound.
10. 9. The organic electroluminescent device according to 8, wherein the phosphorescent compound is a transition metal complex.
11. 11. The organic electroluminescent device according to any one of 1 to 10, wherein the organic electroluminescent device has an electron transport layer, and the electron transport layer contains a compound represented by the general formula (E1).

(In the formula, R _E represents a hydrogen atom or a substituent. X _E represents —O—, —S—, ═N— or ═N—Ra, where Ra represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a hetero group. Q _E represents an atomic group necessary for forming a heterocyclic ring by combining with N and X _E.

12 12. The organic electroluminescent device according to 11, wherein the electron transport layer contains a compound represented by the general formula (E2).

(In the formula, R _E represents a hydrogen atom or a substituent. X _E represents —O—, —S—, ═N— or ═N—Ra, where Ra represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a hetero group. Represents a cyclic group.) Z _E represents a group of atoms necessary to form an aromatic ring.

13. The organic electroluminescent device according to any one of 1 to 10, wherein the organic electroluminescent device has an electron transport layer, and the electron transport layer contains a compound represented by the general formula (E-II).

(Wherein, X _E is -O -, - S -., = N- or = N-Ra (Ra is hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group) .Z _E Represents an atomic group necessary for forming an aromatic ring, B represents a linking group, and m represents an integer of 2 or more.)

14 12. The organic electroluminescent device according to 11, wherein the electron transport layer contains a compound represented by the general formula (E-III).

(In the formula, R _E31 , R _E32 and R _E33 represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group.)

The light-emitting element of the present invention is excellent in light emission characteristics (color purity and external quantum efficiency (φ _EL )) and durability (small increase in drive voltage with time and decrease in luminance), display element, display, backlight, electrophotography, It can be suitably used in fields such as illumination light source, recording light source, exposure light source, reading light source, sign, signboard, interior, and optical communication.

  Hereinafter, the present invention will be described in detail. In the present specification, “to” indicates a range including numerical values described before and after that as a minimum value and a maximum value, respectively.

  The present invention relates to an organic electroluminescent device having a light emitting layer or a plurality of organic layers including a light emitting layer between a pair of electrodes (hereinafter, sometimes referred to as “device of the present invention” or “light emitting device”). It contains at least one kind of metal complex (A) having a Tg of 140 ° C. or higher as a host, a condensed aromatic compound (B) having a thermal decomposition starting temperature of 330 ° C. or higher, and a luminescent material (C). The present invention relates to a characteristic organic electroluminescence device.

  In the present invention, the thermal decomposition start temperature is defined as a temperature at which the weight begins to decrease when the temperature is raised by thermogravimetry (TG). For example, thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) can be measured according to the method described in “Industrial Analytical Chemistry”, Volume 2 (Takeo Takeo, Academic Book Publishing) p154-164. . In the present invention, the glass transition temperature (Tg) and the pyrolysis start temperature are measured by thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) using SSC / 5200 series manufactured by Seiko Instruments Inc. Used.

  The glass transition temperature (Tg) of the metal complex (A) of the present invention is 140 ° C. or higher, preferably 160 ° C. or higher, more preferably 200 ° C. or higher. Although the upper limit of Tg is not particularly limited, it is preferably a high temperature, specifically, preferably 250 ° C. or lower, more preferably 300 ° C. or lower.

  The thermal decomposition starting temperature of the condensed aromatic compound (B) of the present invention is 330 ° C. or higher, preferably 350 ° C. or higher, more preferably 400 ° C. or higher. The upper limit of the thermal decomposition temperature is not particularly limited, but is preferably a high temperature.

  In general, it is recognized that the organic layer including the light emitting layer should contain a material having as high a glass transition temperature as possible, and that the layer having the lowest Tg is attributed to the stability of the organic electroluminescent device. . If the glass transition temperature is low, even if the initial characteristics are high, luminance is lowered and dark spots are generated, which is not practical. The generation of heat when a voltage is applied between the electrodes deteriorates the film quality of the organic layer due to crystallization of the organic layer. However, by using a material having a high glass transition temperature, durability (particularly thermal stability) is improved. Even when a metal complex host having a high glass transition temperature is used, if the carrier mobility is low and the carrier recombination efficiency is low, the luminous efficiency is lowered, and therefore, the generation of Joule heat increases. As a cause of lowering the carrier mobility, trap generation due to decomposition of the compound can be considered. Therefore, as a technical means for improving carrier movement in the light emitting layer, in the element of the present invention, at least one kind of metal complex (A) having a glass transition temperature (Tg) of 140 ° C. or higher as a host in the light emitting layer, 330 It contains a condensed aromatic compound (B) having a thermal decomposition starting temperature not lower than ° C. and a light emitting material (C). In the light emitting layer, A mainly has an electron transport function, and B mainly has a hole transport function. By using B together in the light emitting layer, the interaction of A decreases with holes and prevents degradation such as decomposition from radical cations due to hole injection. The present invention has an effect of further improving the light emission efficiency and light emission luminance of the device, in addition to improving the durability of the device due to the thermal stability of A and B.

The element of the present invention contains at least one of a fluorescent compound and a phosphorescent compound in the light emitting layer as a light emitting material. Fluorescent compounds and phosphorescent compounds may be contained alone or in combination in the light emitting layer. When the fluorescent compound and the phosphorescent compound are contained in the same layer, from the viewpoint of energy transfer efficiency, etc., a region containing the fluorescent compound and the host material, and a region containing the phosphorescent compound and the host material It is preferable to exist separately.
In the element of the present invention, an embodiment that substantially utilizes light emission from the light emitting material (C) is preferable.

  The concentration of the condensed aromatic compound (B) of the present invention in the light emitting layer is preferably 1% by mass to 99% by mass, more preferably 5% by mass to 90% by mass, and more preferably 10% by mass. % To 80% by mass is more preferable.

  The concentration of the metal complex (A) of the present invention in the light emitting layer is preferably 1 to 99% by mass, more preferably 5 to 90% by mass, and more preferably 10 to 80% by mass. More preferably, it is at most mass%.

  The concentration of the light emitting material (C) of the present invention in the light emitting layer is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 10% by mass or less. More preferably, it is at most mass%.

  The mass ratio of the condensed aromatic compound (B) and the metal complex (A) in the light emitting layer is preferably 5: 100 to 100: 5, more preferably 1:10 to 10: 1, and 1: 5 to 5: 1. Further preferred.

  The mass ratio in the light emitting layer of the condensed aromatic compound (B) and the metal complex (A) and the light emitting material (C) is preferably 100: 1 to 100: 50, more preferably 100: 1 to 100: 30, 100: 1 to 100: 10 are more preferable.

  The condensed aromatic compound (condensed aromatic compound) is a condensed aromatic carbocyclic ring or aromatic heterocyclic ring having two or more condensed rings, preferably a condensed aromatic carbocyclic ring having three or more condensed rings. Or it is an aromatic heterocyclic ring. The condensed aromatic carbocycle is preferably anthracene, phenanthracene, tetracene, pyrene, pentacene, perylene, coronene, chrysene, picene, pericyclene, fluoranthene, acenaphthene, etc., and the aromatic heterocycle includes heteroatoms such as nitrogen Condensed aromatic ring having an atom, oxygen atom, sulfur atom (eg pyridine structure, pyrazine structure, pyrimidine structure, pyridazine structure, pyrrole structure, furan structure, thiophene structure, pyrazole structure, imidazole structure, oxazole structure, thiazole structure, triazole structure And more preferably, anthracene, phenanthracene, tetracene, pyrene, pentacene, perylene, fluoranthene, phenanthroline, acridine, phenazine, carbazole, aza Ruoranten and the like, more preferably, phenanthracene, tetracene, pyrene, perylene, fluoranthene, carbazole and the like, particularly preferably pyrene.

The condensed aromatic compound (B) is preferably a compound having at least two or more condensed aromatic carbocycles (provided that when the three condensed aromatic carbocycles are linked to each other, at least two more 4 or more condensed aromatic carbocycles), or an aromatic heterocyclic compound containing at least 2 condensed aromatic heterocycles having 3 or more rings (provided that the 3 condensed aromatic carbocycles are linked to each other) In this case, at least one condensed aromatic ring having 4 or more rings is contained in the molecule).
As the condensed aromatic compound (B), a compound represented by the general formula (1) is preferably used.
In addition to the compound represented by the general formula (1), the compound represented by the general formula (1) described in the pamphlet of International Application Publication (WO) 03 / 007658A2 (here, represented by the general formula (1)) Compounds represented by the general formula (I) are also used, and those belonging to the condensed aromatic compounds defined in claim 2 or 3 are also used. Is indicated by changing the superscript number).

In the formula, Ar ⁹¹ , Ar ⁹² , Ar ⁹³ , Ar ⁹⁴ and Ar ⁹⁵ each represent an aryl group or a heteroaryl group, Ar ⁹ represents a benzene ring, a naphthalene ring, a phenanthrene ring or an anthracene ring, Ar ⁹ , Ar ⁹¹ , Ar ⁹² , Ar ⁹³ , Ar ⁹⁴ and Ar ⁹⁵ are groups having a condensed aryl group or a heteroaryl group, and Ar ⁹¹ , Ar ⁹² , Ar ⁹³ , Ar ⁹⁴ and Ar ⁹⁵ are bonded to each other. And R ⁹¹ represents a substituent, n ⁹¹ represents an integer of 0 or more, and the description of each group is the same as the general formula described in (WO) 03 / 007658A2). is there.

The general formula (1) will be described. Ar ¹¹ , Ar ²¹ and Ar ³¹ represent an arylene group. 6-30 are preferable, as for carbon number of an arylene group, 6-20 are more preferable, and 6-16 are more preferable. Examples of the arylene group include phenylene group, naphthylene group, anthrylene group, phenanthrenylene group, pyrenylene group, peryleneylene group, fluorenylene group, biphenylene group, terphenylene group, rubrenylene group, chrysenylene group, triphenylenylene group, benzoic acid group. An anthrylene group, a benzophenanthrenylene group, a diphenylanthrylene group, a fluorantherylene group and the like can be mentioned, and these arylene groups may further have a substituent.

  Examples of the substituent on the arylene group include an alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms such as methyl, ethyl, and iso-propyl. , Tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, Particularly preferably, it has 2 to 10 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, Particularly preferably, it has 2 to 10 carbon atoms, and examples thereof include propargyl and 3-pentynyl), an aryl group ( Preferably, it has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl, anthranyl, and the like. Preferably it is C0-30, More preferably, it is C0-20, Most preferably, it is C0-10, for example, amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, ditolylamino etc. are mentioned. And alkoxy groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc. An aryloxy group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, Preferably have 6 to 12 carbon atoms, such as phenyloxy, 1-naphthyloxy, 2-naphthyloxy, etc.), heteroaryloxy groups (preferably having 1 to 30 carbon atoms, more preferably 1 carbon atom). -20, particularly preferably 1 to 12 carbon atoms, such as pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy and the like.

An acyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group ( Preferably it has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl and the like, and an aryloxycarbonyl group (preferably having a carbon number). 7 to 30, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl, and acyloxy groups (preferably 2 to 30 carbon atoms, more preferably carbon atoms). 2 to 20, particularly preferably 2 to 10 carbon atoms, for example, acetoxy, benzoyloxy An acylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino). An alkoxycarbonylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms such as methoxycarbonylamino), aryloxycarbonylamino group (Preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino), sulfonylamino group (preferably 1 carbon atom) To 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, Methanesulfonylamino, benzenesulfonylamino, etc.), sulfamoyl groups (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methyl And carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms). For example, carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), alkylthio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, Methylthio, ethylthio, etc.), ants Ruthio group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms, and examples thereof include phenylthio and the like. ),

A heteroarylthio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio and the like), a sulfonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc. ), Sulfinyl groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido A group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, Ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example diethyl phosphorus Acid amide, phenylphosphoric acid amide, etc.), hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxam An acid group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group (preferably having a carbon number of 1 to 30, more preferably a carbon number of 1 to 12, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, Specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, ben Oxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl group, azepinyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, Examples thereof include trimethylsilyl and triphenylsilyl). These substituents may be further substituted.

Ar ¹¹ , Ar ²¹ , Ar ³¹ are preferably a phenylene group, a naphthylene group, an anthrylene group, a phenanthrenylene group, a biphenylene group, or an arylene group having four or more rings (for example, a pyrenylene group or a peryleneylene group), and more preferably. Is a phenylene group, a naphthylene group, a phenanthrene group, an arylene group having 4 or more rings, more preferably a phenylene group, a phenanthrylene group, or a pyrenylene group, and particularly preferably a pyrenylene group.

Ar ¹² , Ar ²² and Ar ³² represent a substituent or a hydrogen atom. Examples of the substituent include the groups described for the substituent on Ar ¹¹ . Ar ¹² , Ar ²² and Ar ³² are preferably a hydrogen atom, an aryl group, a heteroaryl group, an alkyl group or an alkenyl group, more preferably a hydrogen atom, an aryl group or a heteroaryl group, still more preferably a hydrogen atom. And an aryl group, particularly preferably a hydrogen atom or a pyrenyl group.

At least one of Ar ¹¹ , Ar ²¹ , Ar ³¹ , Ar ¹² , Ar ²² and Ar ³² is a condensed ring aryl structure or a condensed ring heteroaryl structure. At least one of Ar ¹¹ , Ar ²¹ , Ar ³¹ , Ar ¹² , Ar ²² , Ar ³² is preferably a condensed ring aryl structure.

  The condensed ring aryl structure is preferably a naphthalene structure, anthracene structure, phenanthrene structure, pyrene structure, perylene structure, more preferably a naphthalene structure, anthracene structure, pyrene structure, or a phenanthrene structure, and more preferably a phenanthrene structure. It is an aryl structure having 4 or more rings, and particularly preferably a pyrene structure.

  The condensed heteroaryl structure is preferably a quinoline structure, a quinoxaline structure, a quinazoline structure, an acridine structure, a phenanthridine structure, a phthalazine structure, a phenanthroline structure, an azafluoranthene structure, more preferably a quinoline structure, A quinoxaline structure, a quinazoline structure, a phthalazine structure, a phenanthroline structure, and an azafluoranthene structure.

Ar represents a polyvalent aromatic ring group (allene which is a trivalent to 10 valent group, and may further have a substituent. Preferably it has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms. More preferably, it has 6 to 16 carbon atoms, such as a phenylene group, a naphthylene group, an anthracenylene group, a phenanthrene group, a pyrenylene group, a triphenylene group, and the like, a heteroarylene group (preferably a nitrogen atom, a sulfur atom, An oxygen atom, more preferably a nitrogen atom, preferably 2 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, still more preferably 3 to 16 carbon atoms, for example, a pyridylene group, a pyrazylene group, a thiophenylene group, a quinolylene group, a quinoxarylene group And triadylene group), and these groups may have a substituent. Examples of the substituent include the groups described for the substituent on Ar ¹¹ . Ar is preferably a phenylene group (benzenetriyl), a naphthylene group (naphthalenetriyl), an anthracenylene group (anthracentriyl), a pyrenylene group (pyrenetriyl), a triphenylene group, more preferably a phenylene group, More preferably, it is an unsubstituted phenylene group or an alkyl-substituted phenylene group (Ar ¹¹ , Ar ²¹ and Ar ³¹ are substituted).

  Preferred forms of the compound represented by the general formula (1) include a compound represented by the following general formula (2), a compound represented by the following general formula (6), and a compound represented by the general formula (I). The compound belonging to claim 2 or 3, wherein a more preferred form is represented by the following general formula (3), the following general formula (4), the following general formula (5) A compound represented by the following general formula (7), a compound represented by the following general formula (8), and a more preferred embodiment is a compound represented by the general formula (3). Moreover, the compound of this invention has a preferable compound comprised only from the carbon atom and the hydrogen atom.

The general formula (2) will be described. Ar ¹¹ in the general formula ^{(2), Ar 21, Ar} 31, Ar 12, Ar 22, Ar 32 and ^{Ar 11, Ar 21, Ar 31} , Ar 12, Ar 22, Ar 32 described in Formula (1) Each is synonymous and the preferred range is also the same. R ¹ , R ² and R ³ each represent a hydrogen atom or a substituent. Examples of the substituent include the groups described for the substituent on Ar ¹¹ . R ¹ , R ² and R ³ are each preferably a hydrogen atom, an alkyl group or an aryl group, more preferably a hydrogen atom or an alkyl group.

In the compounds represented by the general formulas (1) and (2), at least one of Ar ¹¹ , Ar ²¹ , Ar ³¹ , Ar ¹² , Ar ²² , Ar ³² is a phenanthrene structure, a condensed ring structure having four or more rings, or a three ring The compound of the above condensed ring heteroaryl structure is preferable, and a phenanthrene structure and a pyrene structure are more preferable. In addition, the compounds represented by the general formulas (1) and (2) are preferably compounds in which Ar ¹² , Ar ²² , and Ar ³² are condensed ring aryl groups or hydrogen atoms, and Ar ¹² , Ar ²² , and Ar ³² are three rings. The above condensed ring aryl group or hydrogen atom is more preferable, and Ar ¹² , Ar ²² , and Ar ³² are more preferably a phenanthrene structure, a condensed ring aryl structure having four or more rings, or a hydrogen atom. The compounds represented by the general formulas (1) and (2) are preferably compounds in which Ar ¹¹ , Ar ²¹ , and Ar ³¹ are a phenanthrylene group or a condensed ring arylene group having four or more rings.

The general formula (3) will be described. R ¹¹ , R ¹² and R ¹³ represent a substituent. Examples of the substituent include the groups described for the substituent on Ar ¹¹ . R ¹¹ , R ¹² and R ¹³ are preferably an alkyl group, an alkenyl group, an aryl group, a heteroaryl group and an alkoxy group, more preferably an alkyl group and an aryl group, and still more preferably an aryl group.

q ^11, q ^12, q ¹³ represents an integer of 0-9. q ¹¹ , q ¹² and q ¹³ are each preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and still more preferably 0 or 1.

R ¹⁴ , R ¹⁵ and R ¹⁶ have the same meanings as R ¹ , and preferred ranges are also the same.

The general formula (4) will be described. R ⁴¹ , R ⁴² and R ⁴³ have the same meanings as R ¹¹ , and preferred ranges are also the same. R ⁴⁴ , R ⁴⁵ and R ⁴⁶ have the same meanings as R ¹ , and preferred ranges are also the same. q ⁴¹ , q ⁴² and q ^{43 each} represents an integer of 0 to 9, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and further preferably 0 or 1.

The general formula (5) will be described. R ⁵¹ has the same meaning as R ¹¹ , and the preferred range is also the same. R ⁵⁴ , R ⁵⁵ and R ⁵⁶ have the same meaning as R ¹ , and the preferred range is also the same. Ar ⁵¹ represents an anthryl group, a phenanthryl group, and a pyrenyl group, and Ar ⁵² represents a phenanthryl group and a pyrenyl group. Ar ⁵¹ is preferably a phenanthryl group or a pyrenyl group, and more preferably a pyrenyl group. Ar ⁵² is preferably a pyrenyl group. q ⁵¹ represents an integer of 0 to 9, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and further preferably 0 or 1.

The general formula (6) will be described. R ⁶¹ and R ⁶² have the same meaning as R ¹ , and the preferred range is also the same. Ar ⁶¹ , Ar ⁶² , Ar ⁶³ and Ar ^{64 each} represent a condensed aromatic carbocycle, preferably a phenanthryl group, four or more aryl groups, and more preferably a phenanthryl group or a pyrenyl group.

The general formula (7) will be described. R ⁷¹ , R ⁷² , R ⁷³ and R ⁷⁴ have the same meanings as R ¹¹ , and preferred ranges are also the same. R ⁷⁵ and R ⁷⁶ are the same as R ¹ , and the preferred range is also the same. q ⁷¹ , q ⁷² , q ⁷³ , and q ^{74 each} represents an integer of 0 to 9, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and further preferably 0 or 1.

The general formula (8) will be described. R ⁸¹ , R ⁸² , R ⁸³ and R ⁸⁴ have the same meanings as R ¹¹ , and preferred ranges are also the same. R ⁸⁵ and R ⁸⁶ are the same as R ¹ , and preferred ranges are also the same. q ⁸¹ , q ⁸² , q ⁸³ and q ^{84 each} represents an integer of 0 to 9, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and further preferably 0 or 1.

  The light emitting device of the present invention preferably has a form having a compound represented by the general formula (1) having a phenanthrene structure and a compound represented by the general formula (1) having a pyrene structure, and at least one of them is The form containing the compound represented by General formula (3) and the compound represented by General formula (4) is more preferable.

  The condensed aromatic compound (B) of the present invention may be a low molecular compound, and is an oligomer compound or a polymer compound (weight average molecular weight (polystyrene conversion) is preferably 1000 to 5000000, more preferably 2000 to 1000000, still more preferably. May be 3000 to 100,000. In the case of a polymer compound, a condensed aromatic structure may be contained in the polymer main chain, or may be contained in the polymer side chain. In the case of a polymer compound, it may be a homopolymer compound or a copolymer. The compound of the present invention is preferably a low molecular compound.

  The condensed aromatic compound (B) of the present invention preferably has a fluorescence spectrum having a λmax (maximum emission wavelength) of 400 to 500 nm, more preferably 400 to 480 nm, and further preferably 400 to 460 nm. preferable.

  Next, although the compound example of the condensed aromatic compound (B) of this invention is shown, this invention is not limited to this.

  The condensed aromatic compound (B) of the present invention can be synthesized by the method described in JP-A No. 2002-338957.

  Next, the metal complex (A) contained in the light emitting device of the present invention will be described. The metal complex (A) is a metal complex having a ligand having at least one nitrogen atom, oxygen atom or sulfur atom coordinated to a metal, and the metal ion in the metal complex is not particularly limited, but preferably beryllium ion , Magnesium ion, aluminum ion, gallium ion, zinc ion, indium ion, and tin ion, more preferably beryllium ion, aluminum ion, gallium ion, and zinc ion, and still more preferably aluminum ion and zinc ion.

  There are various known ligands contained in the metal complex. For example, “Photochemistry and Photophysics of Coordination Compounds” published by Springer-Verlag H. Yersin in 1987, “Organometallic Chemistry— Examples of the ligands described in “Basics and Applications—” published by Akio Yamamoto, 1982, etc.

  The ligand is preferably a nitrogen-containing heterocyclic ligand (preferably having 1 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 3 to 15 carbon atoms, and a monodentate ligand. Or a bidentate or higher ligand, preferably a bidentate ligand such as a pyridine ligand, a bipyridyl ligand, a quinolinol ligand, a hydroxyphenylazole ligand (hydroxyphenyl) Benzimidazole, hydroxyphenylbenzoxazole ligand, hydroxyphenylimidazole ligand)), alkoxy ligand (preferably 1-30 carbon atoms, more preferably 1-20 carbon atoms, particularly preferably carbon 1-10, for example, methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), aryloxy ligands Preferably it has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 1-naphthyloxy, 2-naphthyloxy, 2,4,6-trimethylphenyl Oxy, 4-biphenyloxy, etc.),

Heteroaryloxy ligand (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.) An alkylthio ligand (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio and ethylthio), arylthio ligand ( Preferably, it has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenylthio, etc., a heteroarylthio ligand (preferably 1 to 1 carbon atoms). 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2 Benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio, etc.), siloxy ligands (preferably having 1 to 30 carbon atoms, more preferably 3 to 25 carbon atoms, particularly preferably 6 to 20 carbon atoms, for example, a triphenylsiloxy group, a triethoxysiloxy group, a triisopropylsiloxy group, and the like. More preferably, a nitrogen-containing heterocyclic ligand, an aryloxy ligand, a hetero An aryloxy group and a siloxy ligand, more preferably a nitrogen-containing heterocyclic ligand, an aryloxy ligand, and a siloxy ligand.

  The metal complex contained in the light emitting layer of the light emitting device of the present invention is preferably the compound represented by the general formula (9), the general formula (10), or a tautomer thereof, more preferably the general formula (9). And a tautomer thereof.

  The compounds represented by the general formulas (9) to (10) are synonymous with the compounds represented by the general formulas (9) to (10) described in JP-A No. 2002-338957 and tautomers thereof, The preferred ranges, specific examples, and synthesis methods are also the same.

  Next, the light emitting material (C) of the present invention will be described. The luminescent material (C) of the present invention may be either a fluorescent compound that emits light from singlet excitons or a phosphorescent compound that emits light from triplet excitons. For example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, condensed aromatic compounds, perinone derivatives, oxadiazole derivatives, Oxazine derivatives, aldazine derivatives, pyralidine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, diketopyrrolopyrrole derivatives, aromatic dimethylidin compounds, Represented by metal complexes of 8-quinolinol derivatives, metal complexes of pyromethene derivatives, rare earth complexes, and transition metal complexes Seed metal complexes, polythiophene, polyphenylene, polymeric compounds such as polyphenylene vinylene, organic silane derivatives, condensed aromatic compound (B), and the like.

The luminescent material of the present invention is preferably a condensed aromatic compound, a styryl compound, a diketopyrrolopyrrole compound, an oxazine compound, a pyromethene metal complex, a transition metal complex, or a lanthanoid complex. Preferably, the condensed aromatic hydrocarbon compound is naphthacene, pyrene, chrysene, triphenylene, benzo [c] phenanthrene, benzo [a] anthracene, bentacene, perylene, fluoranthene, acenaphthofluoranthene, dibenzo [a, j] anthracene , Dibenzo [a, h] anthracene, benzo [a] naphthacene, hexacene, anthanthrene and derivatives thereof. Examples of the condensed aromatic heterocycle include naphtho [2,1-f] isoquinoline, α-naphthaphene, and the like. Examples thereof include nanthridine, phenanthrooxazole, quinolino [6,5-f] quinoline, benzothiophanthrene, azafluoranthene, and derivatives thereof. These may have an aryl group, a heteroaromatic ring group, a diarylamino group, or an alkyl group as a substituent.
The phosphorescence lifetime (room temperature) of the phosphorescent compound of the present invention is not particularly limited, but is preferably 1 ms or less, more preferably 100 μs or less, and even more preferably 10 μs or less.

  The styryl compound is preferably a compound represented by the general formula (11).

In the formula, R ^CX and R ^CY each represent a hydrogen atom or a substituent, and at least one of them represents an electron-withdrawing group, preferably linked to form a ring. R ^C1 , R ^C2 , R ^C3 , R ^C4 and R ^C5 each represents a hydrogen atom or a substituent. L ^C1 and L ^C2 each represents an optionally substituted methylene group, Ar ^C represents an arylene group, X ^C represents an oxygen atom, a sulfur atom, or N—R ^CZ , and R ^CZ represents a hydrogen atom or a substituent. Represents.

  Preferred examples of the compound represented by the general formula (11) include compounds described in JP-A-11-335661, JP-A-2000-351774, JP-A-2003-193044, JP-A-2003-308980, The compound represented by the formula (11a) is raised.

In the general formula (11a), R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ^B11 and R ^B12 are each a hydrogen atom. Or represents a substituent. R ²⁴ represents an aliphatic group, and X represents an oxygen atom, a sulfur atom, or N—R ^Y1 . R ^Y1 represents a hydrogen atom or a substituent. Z ¹¹ represents an atomic group necessary for forming a 5- to 6-membered ring. Z ¹¹ , R ¹³ , R ¹⁴ , R ¹⁵ , R ^B11 , R ^B12 , and X have the same meaning as in general formula (1B) described in JP-A No. 2003-308980, and preferred ranges are also the same. The substituent represented by R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ is the arylene group represented by Ar ¹¹ , Ar ¹² , Ar ^{13 in the} general formula (1). The substituents described as examples of the good substituents may be mentioned, preferably an alkyl group, an aryl group or a heteroaryl group, more preferably an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. . R ²⁴ is preferably a linear, branched or cyclic alkyl group, alkenyl group or aralkyl group having 1 to 10 carbon atoms.
Although the specific example of General formula (11a) is shown, this invention is not limited to this.

  The compound represented by the general formula (11a) can be used as a red light emitting material in an organic electroluminescent device, and may not be limited to the device configuration of the present invention. In addition, the compound represented by the general formula (11a) can be applied to medical use, fluorescent whitening agent, fluorescent display agent, photographic material, UV absorbing material, laser dye, dye for color filter, color conversion filter and the like. is there.

  The diketopyrrolopyrrole compound is preferably a compound represented by the general formula (12).

In the formula, R ^D1 and R ^D2 represent a hydrogen atom or a substituent, and Ar ^D1 and Ar ^D2 represent an aryl group or a heteroaryl group which may have a substituent.

  The oxazine compound is preferably a compound represented by the general formula (13).

In the formula, R ^E1 , R ^E2 , R ^E3 , R ^E4 , R ^E5 , R ^E6 , R ^E7 , and R ^E8 each represent a hydrogen atom or a substituent. X ^E and Y ^{E each} represents an oxygen atom, a sulfur atom, or N—R ^EZ , and R ^EZ represents a hydrogen atom or a substituent.
Examples of the pyromethene complex include a metal complex having a structure represented by the general formula (14) as a partial structure.

In formula, R ^{<F1 >} , R ^{< F2 >} , R ^{< F3 >} , R ^{< F4 >} , R ^{< F5>} , R ^<F6> represents a hydrogen atom or a substituent. X ^F is C—R ^F or a nitrogen atom, and R ^F is a hydrogen atom or a substituent. M ^F represents a metal ion, coordinated if anything better, preferably boron, beryllium, magnesium, chromium, iron, cobalt, nickel, copper, zinc, platinum.
The substituents in general formula (11), general formula (12), general formula (13), and general formula (14) are the arylene groups represented by Ar ¹¹ , Ar ¹² , and Ar ^{13 in} general formula (1). And the substituents described as good substituents.

(Light emitting element)
The light emitting device of the present invention will be described. The light emitting device of the present invention is not particularly limited as long as it is a device using the compounds (A), (B), and (C) of the present invention. An organic EL (electroluminescence) element can be mentioned.

  The method for forming the organic layer of the light emitting device of the present invention is not particularly limited, and methods such as resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method, ink jet method, and printing method are used. Resistance heating vapor deposition, coating method, and transfer method are preferable in terms of characteristics and production.

  The light-emitting device of the present invention is a device in which a light-emitting layer or a plurality of organic layers including a light-emitting layer is formed between a pair of electrodes of an anode and a cathode. In addition to the light-emitting layer, a hole injection layer, a hole transport layer, and an electron injection layer , An electron transport layer, a protective layer, etc., and each of these layers may have other functions. Various appropriate materials can be used for forming each layer.

  The light emitting layer of the organic electroluminescent element of the present invention may have at least one laminated structure of an electron transport compound and a hole transport compound. The light emitting layer may have another layer structure. The number of stacked layers is preferably 2 or more and 50 or less, more preferably 4 or more and 30 or less, and still more preferably 6 or more and 20 or less.

  The thickness of each layer constituting the stack is not particularly limited, but is preferably 0.2 nm or more and 20 nm or less, more preferably 0.4 nm or more and 15 nm or less, further preferably 0.5 nm or more and 10 nm or less, and more preferably 1 nm or more and 5 nm or less. Especially preferred

  The light emitting layer of the organic electroluminescent element of the present invention may have a plurality of domain structures of an electron transport compound and a hole transport compound. The light emitting layer may have another domain structure. The diameter of each domain is preferably from 0.2 nm to 10 nm, more preferably from 0.3 nm to 5 nm, still more preferably from 0.5 nm to 3 nm, and particularly preferably from 0.7 nm to 2 nm.

  The anode supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like, and a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Is a material having a work function of 4 eV or more. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide and indium tin oxide (ITO), metals such as gold, silver, chromium and nickel, and these metals and conductive metal oxides. Inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO, preferably conductive metals It is an oxide, and ITO is particularly preferable from the viewpoint of productivity, high conductivity, transparency, and the like. Although the film thickness of the anode can be appropriately selected depending on the material, it is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 500 nm.

  As the anode, a layer formed on a soda-lime glass, non-alkali glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength, but when glass is used, a thickness of 0.2 mm or more, preferably 0.7 mm or more is usually used. Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (sol-gel method, etc.), a coating of a dispersion of indium tin oxide, etc. A film is formed by this method. The anode can be subjected to cleaning or other treatments to lower the drive voltage of the element and increase the light emission efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment, etc. are effective.

  The cathode supplies electrons to the electron injection layer, the electron transport layer, the light emitting layer, etc., and the adhesion, ionization potential, stability, etc., between the negative electrode and the adjacent layer such as the electron injection layer, electron transport layer, light emitting layer, etc. Selected in consideration of As a material for the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples include an alkali metal (for example, Li, Na, K, etc.) and its fluoride. Or oxides, alkaline earth metals (eg Mg, Ca, etc.) and fluorides or oxides thereof, gold, silver, lead, aluminum, sodium-potassium alloys or their mixed metals, lithium-aluminum alloys or their mixtures Examples thereof include metals, magnesium-silver alloys or mixed metals thereof, rare earth metals such as indium and ytterbium, preferably materials having a work function of 4 eV or less, more preferably aluminum, lithium-aluminum alloys or mixed metals thereof. , Magnesium-silver alloys or mixed metals thereof. The cathode can take not only a single layer structure of the compound and the mixture but also a laminated structure including the compound and the mixture. For example, a laminated structure of aluminum / lithium fluoride and aluminum / lithium oxide is preferable. The film thickness of the cathode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 1 μm.

  For production of the cathode, methods such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, and a coating method are used, and a metal can be vapor-deposited alone or two or more components can be vapor-deposited simultaneously. Furthermore, a plurality of metals can be vapor-deposited simultaneously to form an alloy electrode, or a previously prepared alloy may be vapor-deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

  Although the film thickness of a light emitting layer is not specifically limited, Usually, the thing of the range of 1 nm-5 micrometers is preferable, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm.

  The method for forming the light emitting layer is not particularly limited, but resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method (spin coating method, casting method, dip coating method, etc.), inkjet method, printing method , LB method, transfer method and the like are used, preferably resistance heating vapor deposition and coating method.

  The material of the hole injection layer and the hole transport layer may be any one having a function of injecting holes from the anode, a function of transporting holes, or a function of blocking electrons injected from the cathode. Good. Specific examples include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives. , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline compounds Examples include copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organic silane derivatives, carbon films, and condensed aromatic compounds (B). That. The film thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. . The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

  As a method for forming the hole injection layer and the hole transport layer, a vacuum deposition method, an LB method, a method in which the hole injection / transport material is dissolved or dispersed in a solvent (a spin coating method, a casting method, a dip coating method). Etc.), an inkjet method, a printing method, and a transfer method are used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, and the like.

  The material for the electron injection layer and the electron transport layer may be any material having any one of a function of injecting electrons from the cathode, a function of transporting electrons, and a function of blocking holes injected from the anode. As the material for the electron transport layer, an electron withdrawing group (preferably an electron withdrawing group having a Hammett σp value of 0.2 or more, more preferably an aryl group, an aromatic heterocyclic group, a cyano group, a carbonyl group, Group, thiocarbonyl group, oxycarbonyl group, acylamino group, carbamoyl group, sulfamoyl group, sulfonyl group, imino group, halogen atom, etc.) substituted aromatic carbocyclic compounds (preferably benzene, naphthalene, anthracene, Phenanthracene, tetracene, pyrene, pentacene, perylene, coronene, chrysene, picene, pericyclene, acenaphthene, fluoranthene, etc.), nitrogen-containing aromatic heterocycle (5- to 6-membered aromatic nitrogen-containing heterocycle) As a hetero atom, oxygen atom, nitrogen atom, sulfur atom It may contain a silicon atom and may form 2 to 10 condensed rings such as a pyridine structure, a pyrazine structure, a pyrimidine structure, a pyridazine structure, a pyrrole structure, a pyrazole structure, an imidazole structure, an oxazole structure, a thiazole structure, And triazole structures and combinations thereof.) Compounds, metal complexes, organosilane compounds, and the like.

  Specific examples include fragrances such as triazole, oxazole, oxadiazole, imidazole, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyrandioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, naphthalene, and perylene. Examples include metal complexes of cyclic tetracarboxylic acid anhydrides, phthalocyanines, 8-quinolinol derivatives, metal phthalocyanines, metal complexes represented by benzoxazole and benzothiazole ligands, organosilane compounds, and derivatives thereof. It is done.

  The material contained in the electron transport layer is preferably a compound represented by general formula (I) described in JP-A No. 2002-319491 (here, a compound represented by general formula (I) is represented by general formula (E1)). It is displayed as a compound represented by

(In the formula, R _E represents a hydrogen atom or a substituent. X _E represents —O—, —S—, ═N— or ═N—Ra, where Ra represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a hetero group. Q _E represents a group of atoms necessary to form a heterocycle by combining with N and X. Each group is described in the general formula described in JP-A No. 2002-319491. Same as (I).

  The preferable form of the compound represented by general formula (E1) is the following general formula (E2) or general formula (E-III).

In the formula, R _E and X _E have the same meanings as those in formula (E1). Z _E represents an atomic group necessary for forming an aromatic ring, and is the same as Z described in the general formula (II) described in JP-A-2002-319491.

A more preferable form of the compound represented by the general formula (E2) is the general formula (E-II), in which X _E represents —O—, —S—, ═N— or ═N—Ra (Ra represents Represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group.), Z _E represents an atomic group necessary for forming an aromatic ring, B represents a linking group, and m represents 2 or more. Which is synonymous with that described in the general formula (B-II) described in JP-A No. 2002-319491, and the preferred range is also the same. The general formula (B-III) described in JP-A No. 2002-319491 is also the same. ) To (BX).

In the formula, R _E31 , R _E32 and R _E33 represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group, and are represented by the general formula (C-II) described in JP-A No. 2002-319491. It is synonymous with a compound, and its preferable range is also the same. Specific examples of the compound represented by the general formula (E1) used in the present invention are specific examples (compound numbers 205 to 306 and 367 to 381) described in JP-A No. 2002-319491. It is not limited.
The aryl group or heterocyclic group in the general formulas (E1), (E2), (E-II) and (E-III) is described as a substituent on the arylene group in the general formula (1). Examples of the aryl group or heterocyclic group are the same, and the aliphatic hydrocarbon group is an example of the alkyl group, alkenyl group or alkynyl group described as the substituent on the arylene group of the general formula (1). The same thing is mentioned.
Although the film thickness of an electron injection layer and an electron carrying layer is not specifically limited, The thing of the range of 1 nm-5 micrometers is preferable normally, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

  As a method for forming the electron injection layer and the electron transport layer, a vacuum deposition method, an LB method, a method in which the electron injection / transport material is dissolved or dispersed in a solvent (a spin coating method, a casting method, a dip coating method, etc.), An ink jet method, a printing method, a transfer method, or the like is used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified in the case of the hole injection transport layer can be applied.

As a material for the protective layer, any material may be used as long as it has a function of preventing substances that promote device deterioration such as moisture and oxygen from entering the device. Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ and TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ , SiO _x N _y , polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetra Copolymers obtained by copolymerizing fluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, and a monomer mixture containing tetrafluoroethylene and at least one comonomer. Polymer, fluorine-containing copolymer having a cyclic structure in the copolymer main chain, water absorption of 1% or less The above water-absorbing substances, moisture-proof substances having a water absorption rate of 0.1% or less, and the like are mentioned.

  There is no particular limitation on the method for forming the protective layer. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency excitation ions) Plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, and transfer method can be applied.

  The light-emitting element of the present invention can improve the light extraction efficiency by various known devices. For example, by processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate / ITO layer / organic layer, controlling the film thickness of the substrate / ITO layer / organic layer, etc. It is possible to improve light extraction efficiency and external quantum efficiency.

  The light-emitting element of the present invention may be a so-called top emission method in which light emission is extracted from the cathode side.

  The substrate used in the light-emitting device of the present invention is not particularly limited, but inorganic materials such as zirconia-stabilized yttrium and glass, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polycarbonate, and polyethersulfone. , Polyarylate, allyl diglycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), teflon, polytetrafluoroethylene-polyethylene copolymer, and the like.

[Example]
Examples of the present invention will be described below, but the embodiments of the present invention are not limited thereto.

(Comparative example)
The cleaned ITO substrate is put into a deposition apparatus, copper phthalocyanine is deposited to 10 nm, and α-NPD (N, N′-diphenyl-N, N′-di (α-naphthyl) -benzidine) is deposited to 40 nm thereon to transport holes. A layer was formed. On top of this, red light emitting material (R-1) and Alq (tris (8-hydroxyquinolinato) aluminum) were co-deposited so that the film thickness was 40 nm at 0.02 nm / second and 0.4 nm / second, respectively. A light emitting layer was formed. On top of this, Alq was deposited by 20 nm. A patterned mask (a mask with a light emitting area of 4 mm × 5 mm) is placed on the organic thin film, 5 nm of lithium fluoride is deposited in the deposition apparatus, 500 nm of aluminum is then deposited, and the device is subsequently sealed to form an EL device. (Element No. 101) was produced. After depositing TPD by the same operation as described above, red light emitting material (R-1), Alq (tris (8-hydroxyquinolinato) aluminum) and comparative example compound (host-1) were each 0.02 nm / second, A light emitting layer was formed by co-evaporation so that the film thickness was 40 nm at 0.2 nm / second and 0.2 nm / second. On top of that, Alq was vapor-deposited to 20 nm, and the cathode was vapor-deposited and sealed in the same manner as above to produce an EL element (element No-102).

(Example)
After depositing TPD by the same operation as described above, red light emitting material (R-1), Alq (tris (8-hydroxyquinolinato) aluminum) and the compound (1-1) of the present invention were each 0.02 nm / second, A light emitting layer was formed by co-evaporation so that the film thickness was 40 nm at 0.2 nm / second and 0.2 nm / second. On top of that, Alq was vapor-deposited to 20 nm, and the cathode was vapor-deposited and sealed in the same manner as above to produce an EL element (element No. 103). Furthermore, an EL device was produced in the same manner except that the compound (1-1) of the present invention was changed to (1-63) or (1-89) (device Nos. 104 and 105).

Each element was evaluated as follows. Using a source measure unit 2400 made by Toyo Technica on an organic thin film, a DC constant current is applied to the EL element to cause the comparative example and the element of the present invention to emit light, and the luminance is measured by Topcon's luminance meter BM-8. Was measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics Co., Ltd. to determine the luminous efficiency. Further, a driving durability test was conducted for up to 1000 hours with constant current driving at an initial luminance of 1000 cd / m ² , and the luminance half-life was calculated. The results are shown in Table 1.

  Both the elements 102 and 103 in which a host is further added to the element 101 (Alq host) have improved durability, but the element of the present invention (element 103) is significantly superior to the comparative element. In addition, although the light emission wavelength of the comparative example element (element 102) was shortened by the host-1 mixing and the color purity was deteriorated, the light emission wavelength was not changed in the element of the present invention, and both the color purity and the light emission efficiency were excellent. It was.

  After depositing TPD in the same manner as in Example 1, red light emitting material (R-1), Alq (tris (8-hydroxyquinolinato) aluminum), and compound (1-1) of the present invention were each 0.02 nm / Second, 0.2 nm / second, and 0.2 nm / second were co-evaporated to a film thickness of 40 nm to form a light emitting layer. An electron transport material (E-1) was deposited thereon by 20 nm, and then a cathode was deposited and sealed in the same manner as in Example 1 to produce an EL element (element No-201). Furthermore, an EL device was produced in the same manner except that the compound (R-1) of the present invention was changed to (R-2), (R-3) or (R-4) (device No-202, device 203, Element 204).

Elements 201, 202, 203, and 204 were driven at a low current at the same current value as when element 103 of Example 1 was driven at an initial luminance of 1000 cd / m ² , and the luminance half-life was measured. The results are shown in Table 2.
Table 2

  Luminous efficiency and durability (luminance half-life, element 103 vs. element 201) were improved by changing the electron transport material from Alq to E-1. Furthermore, durability was improved by changing to the condensed ring system materials R-2, R-3, and R-4 as the light emitting material.

Claims (12)

  An organic electroluminescence device having at least one organic layer including a light emitting layer between a pair of electrodes, wherein at least one metal complex having a glass transition temperature (Tg) of 140 ° C. or higher as a host in the light emitting layer An organic electroluminescent device comprising a condensed aromatic compound having a thermal decomposition starting temperature of 330 ° C. or higher and at least one light emitting material. The organic electroluminescent device according to claim 1, wherein the condensed aromatic compound has at least two condensed aromatic carbocyclic rings having three or more rings.
(However, when three condensed aromatic carbocycles are linked to each other, the molecule further contains at least two four or more condensed aromatic carbocycles.) The organic electroluminescent device according to claim 1, wherein the condensed aromatic compound contains at least two condensed aromatic heterocycles having 3 or more rings.
(However, when three condensed aromatic carbocycles are connected to each other, the molecule further contains at least one four or more condensed rings.) The organic electroluminescent device according to claim 1, wherein the condensed aromatic compound is represented by the following general formula (1).

In the formula, Ar represents a polyvalent aromatic ring group, Ar ¹¹ , Ar ²¹ and Ar ³¹ represent an arylene group, and Ar ¹² , Ar ²² and Ar ³² represent a substituent or a hydrogen atom. At least two of Ar ¹¹ , Ar ²¹ , Ar ³¹ , Ar ¹² , Ar ²² , Ar ³² are three or more condensed aromatic carbocyclic rings or condensed aromatic heterocyclic rings.   5. The metal complex according to claim 1, wherein the metal complex is a metal complex having a ligand having at least one nitrogen atom, oxygen atom, or sulfur atom coordinated to a metal. Organic electroluminescent device. The organic electroluminescent device according to any one of claims 1 to 5, wherein the metal complex is represented by the following general formula (9) or general formula (10).

In the general formula (9), M ¹¹ is a metal ion, L ¹¹ is a ligand, X ¹¹ is an oxygen atom, a substituted or unsubstituted nitrogen atom (as a substituent on the nitrogen atom, —SO ₂ R ^a , —COR ^b or —P (═O) (R ^c ) (R ^d ) (R ^a , R ^b , R ^c , R ^d are an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, an amino group, and an alkoxy group, respectively. Represents an aryloxy group or a heterocyclic oxy group), or represents a sulfur atom, Q ¹¹ represents an atomic group forming an aromatic ring, Q ¹² represents an atomic group forming a nitrogen-containing aromatic ring, Q ¹¹ And Q ¹² may combine to form a condensed ring structure, and the ring formed by Q ¹¹ or Q ¹² may have a substituent, m ¹¹ and m ¹² are each an integer of 0 to 3, 1 Represents an integer of ~ 4.

In the general formula (10), L ²¹ and X ²¹ have the same meanings as L ¹¹ and X ¹¹ , and m ²¹ and m ²² represent an integer of 0 to 3 and an integer of 1 to 4, respectively. M ²¹ represents a metal ion. Q ²¹ represents an atomic group forming an aromatic ring. Q ²² represents an atomic group forming a nitrogen-containing aromatic ring. Q ²¹ and Q ²² may be bonded to form a condensed ring structure. The ring formed by Q ²¹ or Q ²² may have a substituent.   7. The light-emitting material is a fluorescent compound, and is a compound selected from a styryl compound, a condensed aromatic compound, a pyromethene complex compound, a diketopyrrolopyrrole compound, and an oxazine compound. The organic electroluminescent element according to one item.   The organic electroluminescent element according to claim 1, wherein the light emitting material is a phosphorescent compound. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device has an electron transport layer, and the electron transport layer contains a compound represented by the general formula (E1). .

(In the formula, R _E represents a hydrogen atom or a substituent. X _E represents —O—, —S—, ═N— or ═N—Ra, where Ra represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a hetero group. Q _E represents a group of atoms necessary to form a heterocyclic ring by combining with N and X _E. ) The organic electroluminescent device according to claim 9, wherein the electron transport layer contains a compound represented by the general formula (E2).

(In the formula, R _E represents a hydrogen atom or a substituent. X _E represents —O—, —S—, ═N— or ═N—Ra, where Ra represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a hetero group. Represents a cyclic group.) Z _E represents a group of atoms necessary to form an aromatic ring. The organic electroluminescent element according to claim 1, wherein the organic electroluminescent element has an electron transport layer, and the electron transport layer contains a compound represented by the general formula (E-II). Light emitting element.

(Wherein, X _E is -O -, - S -., = N- or = N-Ra (Ra is hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group) .Z _E Represents an atomic group necessary for forming an aromatic ring, B represents a linking group, and m represents an integer of 2 or more. The organic electroluminescent element according to claim 9, wherein the electron transport layer contains a compound represented by the general formula (E-III).

(In the formula, R _E31 , R _E32 and R _E33 represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group.)