JP2008031068A - Organic compound, charge transport material, charge transport material composition, and organic electroluminescent device - Google Patents

Abstract

【選択図】なしAn organic compound having a high triplet excitation energy level and excellent solubility in a solvent, a charge transport material comprising the organic compound, high luminance, high efficiency, and long life using the organic compound Provision of organic electroluminescent elements.
The following formula (I) (R ^{1 to} R ⁶ are H or an arbitrary substituent, Ar ¹ is an aromatic hydrocarbon group or the like, Q ¹ is a direct bond, an aromatic hydrocarbon group, Suitable for the production of an organic electroluminescent device by a wet film-forming method using an organic compound represented by the following formula: n is an integer of 2 to 6. Organic electroluminescent device with high brightness, high efficiency and long life.

[Selection figure] None

Description

  The present invention relates to an organic compound having a high triplet excitation energy level, good solubility in a solvent, and particularly useful as a host material for a light emitting layer of an organic electroluminescence device, and a charge transport material comprising the organic compound And a charge transport material composition comprising the organic compound. The present invention also relates to a high-efficiency and long-life organic electroluminescence device using this organic compound.

  In recent years, an electroluminescent element (organic electroluminescent element) using an organic thin film has been developed. Examples of the method for forming the organic thin film include a vacuum deposition method and a wet film forming method. Among these, the wet film forming method does not require a vacuum process, is easy to increase in area, and is easy to mix a plurality of materials having various functions in one layer (coating liquid). There are advantages.

Conventionally, polymer materials such as poly (p-phenylene vinylene) derivatives and polyfluorene derivatives are mainly used as materials for the light emitting layer formed by the wet film forming method. There is a problem like this.
・ It is difficult to control the degree of polymerization and molecular weight distribution of polymer materials.
・ Deterioration due to terminal residues occurs during continuous driving.
・ High purity of the material itself is difficult and contains impurities.

  Due to the above-mentioned problems, an element using a wet film forming method is inferior in driving stability to an element using a vacuum vapor deposition method, and has not reached a practical level except for a part.

  As an attempt to solve the above problems, Patent Document 1 discloses an organic thin film formed by a wet film-forming method by mixing a plurality of low-molecular materials (charge transport materials, light-emitting materials) instead of a polymer compound. The organic electroluminescent element used is described. However, since the organic electroluminescent element described in Patent Document 1 uses fluorescent light emission, the light emission efficiency and the maximum light emission luminance of the element are low, and the practical characteristics are not satisfied.

  In an organic electroluminescent device using an organic thin film made of a plurality of low molecular materials formed by such a wet film forming method, Non-Patent Document 1 uses phosphorescence emission to increase the luminous efficiency of the device. An element is described. In the organic electroluminescent element described in Non-Patent Document 1, the following biphenyl derivatives are used as the charge transport material.

  However, the biphenyl derivative is very easy to crystallize, and it has been difficult to obtain a uniform amorphous film by a wet film forming method. Furthermore, since the biphenyl derivative has low solubility in a solvent, it is necessary to use a halogen-based solvent such as chloroform or 1,2-dichloroethane as a coating solvent. Halogen solvents have a large environmental impact and have practical problems. In addition, since there is a high possibility that the material is deteriorated by impurities contained in the halogen-based solvent, it is considered that an element by a wet film forming method using a halogen-based solvent does not have sufficient driving stability.

  On the other hand, Patent Document 2 discloses an amide compound shown below as an organic electroluminescence material. However, in these amide compounds, it is difficult to maintain a high triplet excitation energy level (T1 level) because the amide bond is cyclic and is linked by π conjugation through an aromatic ring or the like. Further, this amide compound has poor solubility in a solvent and is not suitable for a wet film forming method.

Japanese Patent Laid-Open No. 11-273,859 JP-A-2005-89544 Japanese Journal of Applied Physics Vol.44, No.1B, 2005, pp.626-629

  The present invention includes an organic compound having a high triplet excitation energy level and excellent solubility in a solvent, a charge transport material comprising the organic compound, a charge transport material composition comprising the organic compound, It is an object of the present invention to provide an organic electroluminescence device that uses an organic compound and has high luminance, high efficiency, and long life.

As a result of intensive studies by the present inventors, a compound having the following specific structure has a high triplet excitation energy level and excellent solubility in a solvent. By using this compound, an organic electroluminescent device is obtained. In particular, it has been found that a highly efficient and long-lived device can be obtained in a phosphorescent organic electroluminescent device.
The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

（式（Ｉ）中、Ａｒ^１は、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。Ｒ^１〜Ｒ^６は、それぞれ独立に、水素原子または任意の置換基を表す。Ｑ^１は、直接結合、エーテル基、置換基を有していてもよいアルキレン基、置換基を有していてもよいアミノ基、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。ｎは２〜６の整数を表す。） [1] An organic compound represented by the following formula (I).

(In formula (I), Ar ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ^{1 to} R ⁶ are Each independently represents a hydrogen atom or an arbitrary substituent, Q ¹ represents a direct bond, an ether group, an alkylene group which may have a substituent, an amino group which may have a substituent, or a substituent; Represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and n represents an integer of 2 to 6.)

（式（Ｉ−１）中、Ａｒ^1aおよびＡｒ^1bは、式（Ｉ）におけるＡｒ^１と同義である。Ｒ¹¹〜Ｒ¹⁶、Ｒ²¹〜Ｒ²⁶は、式（Ｉ）におけるＲ^１〜Ｒ^６と同義である。Ｑ^１は上記式（Ｉ）におけると同義である。） [2] The organic compound according to [1], wherein the formula (I) is represented by the following formula (I-1).

(In Formula (I-1), Ar ^1a and Ar ^1b have the same meaning as Ar ¹ in Formula (I). R ^{11 to} R ¹⁶ and R ^{21 to} R ²⁶ represent R ^{1 to} R in Formula (I). ⁶ synonymous .Q ¹ has the same meaning as in the formula (I).)

[3] In the above formula (I), Q ¹ is a linking group that does not conjugate n partial structures represented by the following formula (i) constituting the compound represented by the above formula (I). The organic compound according to [1] or [2].

（式（II）中、Ａｒ^２は、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。Ｒ³¹〜Ｒ³³は、それぞれ独立に、水素原子または任意の置換基を表す。ｍは１〜６の整数を表す。ｍが１の場合、式（II）で表される化合物中に、Ｎ＝Ｎ結合を有することはない。また、式（II）において、カルボニル基が結合しているベンゼン環は該カルボニル基以外にも置換基を有していてもよい。） [4] An organic compound represented by the following formula (II).

(In formula (II), Ar ² represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ^{31 to} R ³³ are Each independently represents a hydrogen atom or an arbitrary substituent, m represents an integer of 1 to 6. When m is 1, the compound represented by formula (II) has an N = N bond. (In addition, in formula (II), the benzene ring to which the carbonyl group is bonded may have a substituent other than the carbonyl group.)

（式（II−１）中、Ａｒ^2bおよびＡｒ^2aは、式（II）におけるＡｒ^２と同義である。Ｒ⁴¹〜Ｒ⁴⁶は、式（II）におけるＲ³¹〜Ｒ³³と同義である。また、式（II）において、２個のカルボニル基が結合しているベンゼン環は該カルボニル基以外にも置換基を有していてもよい。） [5] The organic compound according to [4], wherein the formula (II) is represented by the following formula (II-1).

(In the formula (II-1), Ar ^2b and Ar ^2a is .R ⁴¹ to R ⁴⁶ are synonymous with Ar ² in the formula (II) has the same meaning as R ³¹ to R ³³ in formula (II). In addition, in the formula (II), the benzene ring to which two carbonyl groups are bonded may have a substituent other than the carbonyl group.)

[6] A charge transport material comprising the organic compound according to any one of [1] to [5].

[7] A composition for a charge transport material, comprising the organic compound according to any one of [1] to [5].

[8] The charge transport material composition as described in [7], further comprising a solvent.

[9] In an organic electroluminescence device having an anode, a cathode, and a light emitting layer sandwiched between the anode and the cathode on a substrate, using the composition for a charge transport material according to [7] or [8], An organic electroluminescence device comprising a layer formed by a wet film formation method.

[10] In an organic electroluminescent element having an anode, a cathode, and a light emitting layer sandwiched between the anode and the cathode on a substrate, the layer containing the organic compound according to any one of [1] to [5] An organic electroluminescent device comprising:

The organic compound of the present invention represented by the formula (I) or (II) has a high triplet excitation energy level and is excellent in solubility in various solvents. Moreover, these compounds are easy to synthesize.
Therefore, the charge transport material comprising the organic compound of the present invention is suitable for the production of an organic electroluminescent device by a wet film-forming method. By using such a charge transport material of the present invention, particularly in a blue phosphorescent light-emitting device. An organic electroluminescence device having high brightness, high efficiency and long life is provided.

  The organic electroluminescent element using the organic compound of the present invention is a light source (for example, a copy) that takes advantage of the characteristics of a flat panel display (for example, for an OA computer or a wall-mounted television), an in-vehicle display element, a mobile phone display or a surface light emitter. It can be applied to machine light sources, back light sources for liquid crystal displays and instruments, display panels, and sign lamps, and its technical value is great.

  Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. It is not specified in the contents.

[Organic compounds]
The organic compound of the present invention is represented by the following formula (I) or (II).

（式（Ｉ）中、Ａｒ^１は、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。Ｒ^１〜Ｒ^６は、それぞれ独立に、水素原子または任意の置換基を表す。Ｑ^１は、直接結合、エーテル基、置換基を有していてもよいアルキレン基、置換基を有していてもよいアミノ基、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。ｎは２〜６の整数を表す。）

(In formula (I), Ar ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ^{1 to} R ⁶ are Each independently represents a hydrogen atom or an arbitrary substituent, Q ¹ represents a direct bond, an ether group, an alkylene group which may have a substituent, an amino group which may have a substituent, or a substituent; Represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and n represents an integer of 2 to 6.)

（式（II）中、Ａｒ^２は、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。Ｒ³¹〜Ｒ³³は、それぞれ独立に、水素原子または任意の置換基を表す。ｍは１〜６の整数を表す。ｍが１の場合、式（II）で表される化合物中に、Ｎ＝Ｎ結合を有することはない。また、式（II）において、カルボニル基が結合しているベンゼン環は該カルボニル基以外にも置換基を有していてもよい。）

(In formula (II), Ar ² represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ^{31 to} R ³³ are Each independently represents a hydrogen atom or an arbitrary substituent, m represents an integer of 1 to 6. When m is 1, the compound represented by formula (II) has an N = N bond. (In addition, in formula (II), the benzene ring to which the carbonyl group is bonded may have a substituent other than the carbonyl group.)

<Compound represented by formula (I)>
Since the compound represented by the formula (I) is a compound in which a block having a high triplet excitation energy level is bonded with an amide group, each compound can maintain a high triplet excitation energy level. In addition, it is presumed that a highly efficient and long-life device can be provided in an organic electroluminescent element, particularly a phosphorescent organic electroluminescent element, which is excellent in solvent solubility.

(1) Ar ¹
Ar ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ¹ usually has a molecular weight of preferably 60 or more and 1000 or less, more preferably 500 or less, including its substituents.

  The aromatic hydrocarbon group is usually a group having 5 to 70 carbon atoms, preferably 6 to 30 carbon atoms, and is preferably a group derived from a 5- or 6-membered monocyclic ring or a 2-5 condensed ring. Examples include groups derived from aromatic hydrocarbon rings such as a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, and fluoranthene ring.

  The aromatic heterocyclic group is usually a group having 4 to 70 carbon atoms, preferably 5 to 30 carbon atoms, preferably a group derived from a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. Specific examples include pyridine ring, pyrazole ring, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolo Pyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyrazine ring, pyrimidine ring, triazine Ring, quinoline ring, isoquinoline ring, sinoline ring Quinoxaline ring, a benzimidazole ring, perimidine ring, a quinazoline ring, a quinazolinone ring, an aromatic heterocyclic group derived from azulene ring.

  Among these, a group derived from a benzene ring is particularly preferable because of its high triplet excitation energy level and high glass transition temperature.

Moreover, the aromatic hydrocarbon group or aromatic heterocyclic group of Ar ¹ may have a substituent. Examples of the substituent include those exemplified below as optional substituents for R ^{1 to} R ⁶ .

Ar ¹ may or may not have a substituent, but is preferably substituted with a condensed ring such as a carbazole ring or a dibenzofuran ring in order to increase the glass transition temperature (Tg) of the compound. . Ar ¹ is particularly preferably a benzene ring-derived group (phenyl group) having a carbazole ring as a substituent or a phenyl group having no substituent.

A plurality of Ar ¹ contained in one molecule of the compound represented by formula (I) may be the same or different, but are preferably the same from the viewpoint of ease of synthesis.

(2) R ^{1 to} R ⁶
R ^{1 to} R ⁶ each independently represent a hydrogen atom or an arbitrary substituent.

  Specific examples of the optional substituent include an alkyl group having 1 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, an acyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, C6-C30 aryloxy group, C5-C30 heteroaryloxy group, C1-C30 alkylthio group, C6-C30 arylthio group, C5-C30 heteroarylthio group, Carbon number 1 to 30 alkoxycarbonyl groups, 6 to 30 aryloxycarbonyl groups, 5 to 30 heteroaryloxycarbonyl groups, halogen atoms, 6 to 30 arylamino groups, 5 to 30 heteroaryls Examples thereof include an amino group, an alkylamino group having 1 to 30 carbon atoms, and an aromatic heterocyclic group having 5 to 30 members, more preferably an alkyl group having 1 to 30 carbon atoms and 1 carbon atom. 30 alkoxy group, aromatic hydrocarbon group having 6 to 30 carbon atoms and an aromatic heterocyclic group of membered 5-30. Preferably, it is a C1-C30 alkyl group, a C1-C30 alkoxy group, a C6-C30 aromatic hydrocarbon group, or a C5-C30 aromatic heterocyclic group.

  From the viewpoint of a high triplet excitation level, more preferably, a 1 to 30 alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, a phenyl group, or a benzene ring formed by connecting a plurality of them. A valent group (for example, biphenyl group, terphenyl group, etc.) or a carbazolyl group, and most preferably a monovalent group (for example, biphenyl group, terphenyl group) formed by linking 2 to 8 phenyl groups or benzene rings. Group), and a carbazolyl group. In the case of a monovalent group formed by connecting the benzene rings, the benzene ring is preferably connected at the meta position.

  The above substituents may further have an arbitrary number of substituents at arbitrary positions. As the substituent, preferably an alkyl group having 1 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, an acyl group having 1 to 30 carbon atoms, particularly an acyl group having an alkyl group or a phenyl group, An alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, a heteroaryloxy group having 5 to 30 carbon atoms, an alkylthio group having 1 to 30 carbon atoms, an arylthio group having 6 to 30 carbon atoms, and 5 to 5 members 30 heteroarylthio groups, C1-C30 alkoxycarbonyl groups, C6-C30 aryloxycarbonyl groups, C5-C30 heteroaryloxycarbonyl groups, halogen atoms, C6-C30 arylamino Group, a heteroarylamino group having 5 to 30 members, an alkylamino group having 1 to 30 carbon atoms, and an aromatic heterocyclic group having 5 to 30 members. Preferably, it is an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, or an aromatic heterocyclic group having 5 to 30 members, more preferably A C1-C30 alkyl group, a C1-C30 alkoxy group, a phenyl group, or a monovalent group formed by connecting 1 to 8 benzene rings (for example, a biphenyl group, a terphenyl group, etc.), A phenylamino group (such as a diphenylamino group) which may have a substituent, or an N-carbazolyl group which may have a substituent. Examples of the substituent for the phenylamino group and the N-carbazolyl group include an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, and an aryl group having 6 to 30 carbon atoms.

In addition, R ^{1 to} R ⁶ may form a ring that may have a substituent by bonding adjacent groups to each other as long as the conjugated system does not extend. Here, “adjacent” does not necessarily refer to a substituent substituted on an adjacent carbon atom on the same benzene ring, but refers to a state in which they can be bonded to each other in terms of molecular structure. In the case where this ring further has a substituent, examples of the substituent include those exemplified as the substituent that R ^{1 to} R ^{6 and the} like may further have.

A plurality of R ^{1 to} R ⁶ contained in one molecule of the compound represented by the formula (I) may be the same or different, but are preferably the same for ease of synthesis.

Further, each of the substituents R ^{1 to} R ⁶ preferably has a molecular weight of 1000 or less, and more preferably 500 or less.

In particular, when R ^{1 to} R ⁶ are optional substituents, the most preferable substituent is an N-carbazolyl group or a dibenzofuryl group, and particularly preferably an N-carbazolyl group.

From the viewpoint of solubility of the compound in a solvent, when R ^{1 to} R ^{6 have} an arbitrary substituent, it has a bonding position with a carbonyl group of a benzene ring having R ^{1 to} R ³ or R ^{4 to} R ⁶ . The position of the m position (namely, R ¹ , R ³ , R ⁴ , R ⁶ ) is substituted with respect to the bonding position with the nitrogen atom of the benzene ring, and the position of the p position is a hydrogen atom (ie, R ² , R ⁵ ) Is preferable.

(3) Q ¹
Q ¹ is a direct bond, an ether group, an alkylene group which may have a substituent, an amino group which may have a substituent, an aromatic hydrocarbon group or a substituent which may have a substituent. Represents an aromatic heterocyclic group which may have
However, in order to realize a high triplet excitation energy level, Q ¹ conjugates n partial structures represented by the following formula (i) constituting the compound represented by the formula (I). It is preferable that the linking group is not allowed to be bonded, and therefore it is preferable that the linking group is not a direct bond. That is, for example, when Q ¹ is linked to Ar ¹ , it is not preferable that Q ¹ is a direct bond because Ar ¹ is conjugated with Ar ¹ -Ar ¹ .

As the linking group for Q ¹ , those having a molecular weight of 100 or less are usually preferred.

The alkylene group for Q ¹ is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and an alkylene group having 1 carbon atom, that is, a methylene group. Is particularly preferred.
As the amino group of Q ¹ , it is preferable that each bond is bonded to the formula (i). That is, it is preferably a tertiary amino group. Among them, it is preferable that two bonds are bonded to the formula (i) and one is a substituent.
Examples of the aromatic hydrocarbon group for Q ¹ include the divalent groups of the aromatic hydrocarbon groups exemplified as Ar ¹ , and preferably a benzene ring or a group formed by connecting 2 to 8 benzene rings. .
Examples of the aromatic heterocyclic group for Q ¹ include the divalent groups of the aromatic heterocyclic group exemplified as Ar ¹ , and preferred examples include groups derived from a thiophene ring, a pyrazole ring, and a triazine ring.
Examples of the substituent that the alkyl group, amino group, aromatic hydrocarbon group, or aromatic heterocyclic group may have include those exemplified as R ^{1 to} R ⁶ .
Furthermore, the linking group Q ¹ is, like groups attached to the linking group Q ¹ and the linking group Q ¹ is bonded to may form a ring. In this case, examples of the ring formed include a carbazole ring and a dibenzofuran ring.

(4) n
n represents an integer of 2 to 6. Preferably 2 to 3, particularly preferably 2.

(5) More preferred compound The compound represented by the above formula (I) is particularly preferably a compound represented by the following formula (I-1).

（式（Ｉ−１）中、Ａｒ^1aおよびＡｒ^1bは、式（Ｉ）におけるＡｒ^１と同義である。Ｒ¹¹〜Ｒ¹⁶、Ｒ²¹〜Ｒ²⁶は、式（Ｉ）におけるＲ^１〜Ｒ^６と同義である。Ｑ^１は上記式（Ｉ）におけると同義である。）

(In Formula (I-1), Ar ^1a and Ar ^1b have the same meaning as Ar ¹ in Formula (I). R ^{11 to} R ¹⁶ and R ^{21 to} R ²⁶ represent R ^{1 to} R in Formula (I). ⁶ synonymous .Q ¹ has the same meaning as in the formula (I).)

In the formula (I-1), Ar ^1a and Ar ^1b have the same meanings as Ar ¹ in the formula (I), and preferred examples thereof are also the same.
R ^{11 to} R ¹⁶ and R ^{21 to} R ²⁶ have the same meanings as R ^{1 to} R ⁶ in formula (I), respectively, and preferred examples thereof are also the same.

As Q ¹ , the following are preferable including Ar ^1a and Ar ^1b .

<Compound represented by formula (II)>
The compound represented by the formula (II) has a high triplet excitation energy level and also has an amide bond, and thus has excellent solvent solubility. In addition, it is presumed that an organic electroluminescent element, particularly a phosphorescent organic electroluminescent element, can provide a highly efficient and long-life device.

Ar ² in the formula (II) includes the same as Ar ¹ in the formula (I), and preferred examples thereof are also the same.
Examples of R ^{31 to} R ³³ include the same as R ^{1 to} R ³ in formula (I), and preferred examples thereof are also the same.

When the benzene ring to which the carbonyl group is bonded has a substituent other than the carbonyl group, examples of the substituent include those exemplified as the optional substituents of R ^{1 to} R ⁶ described above. Does not have a substituent.

  m is an integer of 1 to 6, preferably 1 to 3, particularly preferably 2.

  The compound represented by the formula (II) is particularly preferably a compound represented by the following formula (II-1).

（式（II−１）中、Ａｒ^2bおよびＡｒ^2aは、式（II）におけるＡｒ^２と同義である。Ｒ⁴¹〜Ｒ⁴⁶は、式（II）におけるＲ³¹〜Ｒ³³と同義である。また、式（II）において、２個のカルボニル基が結合しているベンゼン環は該カルボニル基以外にも置換基を有していてもよい。）

(In the formula (II-1), Ar ^2b and Ar ^2a is .R ⁴¹ to R ⁴⁶ are synonymous with Ar ² in the formula (II) has the same meaning as R ³¹ to R ³³ in formula (II). In addition, in the formula (II), the benzene ring to which two carbonyl groups are bonded may have a substituent other than the carbonyl group.)

In the formula (II-1), Ar ^2b and Ar ^2a have the same meaning as Ar ² in the formula (II), and preferred examples thereof are also the same.
R ^{41 to} R ⁴⁶ have the same meanings as R ^{31 to} R ³³ in formula (II), and preferred examples thereof are also the same.

<Molecular weight of organic compound>
The molecular weight of the organic compound of the present invention represented by the formula (I) or formula (II) is usually 5000 or less, preferably 4000 or less, more preferably 3000 or less, and usually 200 or more, preferably 300 or more, More preferably, it is 400 or more. If the molecular weight exceeds this upper limit, purification may become difficult due to the high molecular weight of impurities, and if the molecular weight falls below this lower limit, the glass transition temperature, melting point, vaporization temperature, etc. will decrease. There is a risk that the properties are significantly impaired.

<Synthesis method (raw material, catalyst, solvent, temperature, pressure, molar ratio, isolation method, purification method)>
The organic compound of the present invention can be synthesized by selecting a raw material according to the structure of the target compound and using a known method.

Examples of the synthesis method include the following methods.
That is, first, a carboxylic acid (Ar′OOH) represented by the following formula (a) is inert with a primary arylamine (Ar ″ NH ₂ ) via an acid chloride or in the presence of a condensing agent. The secondary amide derivative represented by the formula (b) is obtained by stirring and mixing at 20 to 300 ° C. for 1 to 60 hours in a solvent such as a solvent-free or aromatic solvent or ether solvent in a gas stream.
Next, the secondary amide derivative represented by the formula (b) and the halide (Q- (Ar ′ ″-X) _n ) are mixed with copper powder, copper (I) halide, copper (I) oxide, Transition metal catalysts such as palladium complexes (about 0.001 to 5 equivalents with respect to the halogen atom) and basic substances such as potassium carbonate, calcium carbonate, potassium phosphate, cesium carbonate, tert-butoxy sodium, triethylamine (halogen) 1 to 10 equivalents per atom), and optionally in the presence of a ligand, in an inert gas stream, in a solvent-free or solvent such as an aromatic solvent or an ether solvent at 20 to 300 ° C. The compound represented by the formula (c) is obtained by stirring and mixing for 1 to 60 hours.
If these reactions are carried out stepwise, an asymmetric compound can be obtained.
In the following reaction formula, Ar ′, Ar ″, Ar ′ ″ represent an aromatic ring, Q represents Q ¹ , and X represents a halogen atom.

As a purification method of the synthesized compound, “Separation and purification technology handbook” (1993, edited by The Chemical Society of Japan), “High-level separation of trace components and difficult-to-purify substances by chemical conversion method” (1988, ) Issued by IPC), or the methods described in the section “Separation and purification” in “Experimental Chemistry Course (4th edition) 1” (1990, edited by The Chemical Society of Japan) Is available.
Specifically, extraction (including suspension washing, boiling washing, ultrasonic washing, acid-base washing), adsorption, occlusion, melting, crystallization (including recrystallization from solvent, reprecipitation), distillation (atmospheric pressure) Distillation, vacuum distillation), evaporation, sublimation (atmospheric pressure sublimation, vacuum sublimation), ion exchange, dialysis, filtration, ultrafiltration, reverse osmosis, pressure osmosis, zone lysis, electrophoresis, centrifugation, flotation separation, sedimentation separation, Magnetic separation, various chromatography (shape classification: column, paper, thin layer, capillary. Mobile phase classification: gas, liquid, micelle, supercritical fluid. Separation mechanism: adsorption, distribution, ion exchange, molecular sieve, chelate, gel filtration , Exclusion, affinity) and the like.

The product confirmation and purity analysis methods include gas chromatograph (GC), high performance liquid chromatograph (HPLC), high speed amino acid analyzer (AAA), capillary electrophoresis measurement (CE), size exclusion chromatograph (SEC), Gel permeation chromatograph (GPC), cross-fractionation chromatograph (CFC) mass spectrometry (MS, LC / MS, GC / MS, MS / MS), nuclear magnetic resonance apparatus (NMR ( ¹ HNMR, ¹³ CNMR)), Fourier transform Infrared spectrophotometer (FT-IR), UV-visible near-infrared spectrophotometer (UV.VIS, NIR), electron spin resonance apparatus (ESR), transmission electron microscope (TEM-EDX), electron beam microanalyzer (EPMA) , Metal element analysis (ion chromatograph, inductively coupled plasma-emission spectroscopy (ICP-AES) atomic absorption (AAS) X-ray fluorescence analyzer (XRF)), nonmetal element analysis, trace analysis (ICP-MS, GF-AAS, optionally a GD-MS), etc., it is applicable.

<Physical properties>
The organic compound of the present invention usually has a glass transition temperature (Tg) of 50 ° C. or higher, but from the viewpoint of heat resistance, the glass transition temperature is preferably 80 ° C. or higher, and more preferably 110 ° C. or higher. . The upper limit of the glass transition temperature of the organic compound of the present invention is usually 300 ° C. or lower.
Moreover, the organic compound of this invention has a vaporization temperature of 300 to 800 degreeC normally.
The organic compound of the present invention preferably has no crystallization temperature between the glass transition temperature and the vaporization temperature.

<Specific examples of compounds>
Although the preferable specific example of the organic compound of this invention represented by the said formula (I) or formula (II) below is shown, this invention is not limited to these. In the following examples, Me is a methyl group.

<Application>
The organic electroluminescent element using the organic compound of the present invention is a light source (for example, a copy) that takes advantage of the characteristics of a flat panel display (for example, for an OA computer or a wall-mounted television), an in-vehicle display element, a mobile phone display or a surface light emitter. It can be applied to machine light sources, back light sources for liquid crystal displays and instruments, display panels, and sign lamps, and its technical value is great.
The organic compound of the present invention is useful not only for organic electroluminescent devices but also for electrophotographic photoreceptors.

  The organic compound of the present invention is not only used for charge transport materials, but also for various light emitting materials, for solar cell materials, for battery materials (electrolytes, electrodes, separation membranes, stabilizers, etc.), medical use, and paint materials. It is also useful for coating materials, coating materials, organic semiconductor materials, toiletry materials, antistatic materials, thermoelectric element materials, and the like.

  In particular, the organic compound of the present invention is preferably used as a charge transport material, and since it has a high triplet excitation level, it is preferably used as a host material of the light-emitting material of the light-emitting layer, particularly for blue light-emitting materials. It is preferably used as a host material.

[Charge transport material composition]
The charge transport material composition of the present invention comprises the organic compound of the present invention represented by the formula (I) and / or the organic compound of the present invention represented by the formula (II), and preferably a solvent. Yes, preferably used for organic electroluminescent devices. The charge transport material composition of the present invention contains one or more of the organic compound of the present invention represented by formula (I) and / or the organic compound of the present invention represented by formula (II). It may also contain other charge transport materials.

[1] Solvent The solvent contained in the charge transport material composition of the present invention is not particularly limited as long as the organic compound of the present invention which is a solute dissolves well.

  Since the organic compound of the present invention has very high solubility in a solvent, various solvents can be applied. For example, aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene and tetralin; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene and anisole , Phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole and other aromatic ethers; phenyl acetate, phenyl propionate, methyl benzoate, benzoic acid Aromatic esters such as ethyl, propyl benzoate and n-butyl benzoate; ketones having an alicyclic ring such as cyclohexanone and cyclooctanone; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; methyl ethyl ketone and cyclohexano Alcohol having an alicyclic ring such as ruthenium or cyclooctanol; Aliphatic alcohol such as butanol or hexanol; Aliphatic ether such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether or propylene glycol-1-monomethyl ether acetate (PGMEA); Ethyl acetate In addition, aliphatic esters such as n-butyl acetate, ethyl lactate, and n-butyl lactate can be used. Of these, aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene, tetralin and the like are preferable in that they have low water solubility and are not easily altered.

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

  Examples of the method for reducing the amount of water in the composition include nitrogen gas sealing, use of a desiccant, dehydration of the solvent in advance, use of a solvent having low water solubility, and the like. In particular, it is preferable to use a solvent having low water solubility because the solution film can prevent whitening by absorbing moisture in the atmosphere during the wet film-forming process. From such a viewpoint, the charge transport material composition to which the present embodiment is applied includes, for example, a solvent having a water solubility at 25 ° C. of 1% by weight or less, preferably 0.1% by weight or less. It is preferable to contain 10 weight% or more in a thing.

  Further, in order to reduce deterioration in film formation stability due to solvent evaporation from the composition during wet film formation, the solvent of the charge transport material composition has a boiling point of 100 ° C. or higher, preferably 150 ° C. or higher. More preferably, it is effective to use a solvent having a boiling point of 200 ° C. or higher. In order to obtain a more uniform film, it is necessary for the solvent to evaporate from the liquid film immediately after film formation at an appropriate rate. For this purpose, the boiling point is usually 80 ° C. or higher, preferably 100 ° C. or higher. It is effective to use a solvent having a boiling point of 120 ° C. or more, usually less than 270 ° C., preferably less than 250 ° C., more preferably less than 230 ° C.

  A solvent that satisfies the above-mentioned conditions, ie, solute solubility, evaporation rate, and water solubility conditions, may be used alone. However, if a solvent that satisfies all the conditions cannot be selected, two or more solvents may be mixed. It can also be used.

[2] Luminescent Material The charge transport material composition of the present invention, particularly the charge transport material composition used as a composition for an organic electroluminescence device, preferably contains a luminescent material.

The light emitting material refers to a component that mainly emits light in the charge transport material composition of the present invention, and corresponds to a dopant component in an organic electroluminescent device. That is, the amount of light emitted from the charge transport material composition (unit: cd / m ² ) is usually 10 to 100%, preferably 20 to 100%, more preferably 50 to 100%, and most preferably 80 to 100%. Is identified as light emission from a component material, it is defined as the light emission material.

Any known material can be applied as the light-emitting material, and a fluorescent light-emitting material or a phosphorescent light-emitting material can be used singly or as a mixture of a plurality of materials. From the viewpoint of internal quantum efficiency, a phosphorescent light-emitting material is preferable.
The maximum emission peak wavelength of this luminescent material is preferably in the range of 390 to 490 nm.

  For the purpose of improving the solubility in a solvent, it is also important to reduce the symmetry and rigidity of the light emitting material molecule or introduce a lipophilic substituent such as an alkyl group.

  Examples of fluorescent dyes that emit blue light include perylene, pyrene, anthracene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof. Examples of the green fluorescent dye include quinacridone derivatives and coumarin derivatives. Examples of yellow fluorescent dyes include rubrene and perimidone derivatives. Examples of red fluorescent dyes include DCM compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene and the like.

  Examples of the phosphorescent material include organometallic complexes containing a metal selected from Groups 7 to 11 of the periodic table.

Preferred examples of the metal in the phosphorescent organometallic complex containing a metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Preferred examples of these organometallic complexes include compounds represented by the following general formula (V) or formula (VI).
ML _(q−j) L ′ _j (V)
(In general formula (V), M represents a metal, q represents the valence of the metal, L and L ′ represent a bidentate ligand, and j represents 0, 1 or 2.)

（一般式（VI）中、Ｍ^ｄは金属を表し、Ｔは炭素または窒素を表す。Ｒ^９２〜Ｒ^９５は、それぞれ独立に置換基を表す。ただし、Ｔが窒素の場合は、Ｒ^９４およびＲ^９５は無い。）

(In the general formula (VI), M ^d represents a metal, T represents carbon or nitrogen. R ^{92 to} R ⁹⁵ each independently represents a substituent. However, when T is nitrogen, R ⁹⁴ and R ⁹⁵ is not.)

Hereinafter, the compound represented by the general formula (V) will be described first.
In the general formula (V), M represents an arbitrary metal, and specific examples of preferable ones include the metals described above as the metal selected from Groups 7 to 11 of the periodic table.
Moreover, the bidentate ligands L and L ′ in the general formula (V) each represent a ligand having the following partial structure.

As L ′, the followings are particularly preferable from the viewpoint of the stability of the complex.

  In the partial structures of L and L ′, the ring A1 represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and these may have a substituent. Ring A2 represents a nitrogen-containing aromatic heterocyclic group, and these may have a substituent.

  When the rings A1 and A2 have a substituent, preferred substituents include halogen atoms such as fluorine atoms; alkyl groups such as methyl groups and ethyl groups; alkenyl groups such as vinyl groups; methoxycarbonyl groups and ethoxycarbonyl groups. Alkoxycarbonyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups and benzyloxy groups; dialkylamino groups such as dimethylamino groups and diethylamino groups; diarylamino groups such as diphenylamino groups; carbazolyl groups; An acyl group such as an acetyl group; a haloalkyl group such as a trifluoromethyl group; a cyano group; an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, and a phenanthyl group.

  More preferable examples of the compound represented by the general formula (V) include compounds represented by the following general formulas (Va), (Vb), and (Vc).

（一般式（Ｖａ）中、Ｍ^ａはＭと同様の金属を表し、ｗは上記金属の価数を表す。また、環Ａ１は置換基を有していてもよい芳香族炭化水素基を表し、環Ａ２は置換基を有していてもよい含窒素芳香族複素環基を表す。）

(In general formula (Va), M ^a represents the same metal as M, w represents the valence of the metal, and ring A1 represents an aromatic hydrocarbon group which may have a substituent. Ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.

（一般式（Ｖｂ）中、Ｍ^ｂはＭと同様の金属を表し、ｗは上記金属の価数を表す。また、環Ａ１は置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表し、環Ａ２は置換基を有していてもよい含窒素芳香族複素環基を表す。）

(In the general formula (Vb), M ^b represents the same metal as M, w represents the valence of the metal. Further, the ring A1 is an aromatic optionally substituted hydrocarbon group or a substituted Represents an aromatic heterocyclic group which may have a group, and ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.)

（一般式（Ｖｃ）中、Ｍ^ｃはＭと同様の金属を表し、ｗは上記金属の価数を表す。また、ｊは０、１または２を表す。さらに、環Ａ１および環Ａ１’は、それぞれ独立に、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。また、環Ａ２および環Ａ２’は、それぞれ独立に、置換基を有していてもよい含窒素芳香族複素環基を表す。）

(In the general formula (Vc), M ^c represents the same metal as M, w represents the valence of the metal, and j represents 0, 1 or 2. Further, ring A1 and ring A1 ′ represent Each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, and ring A2 and ring A2 ′ are each independently Represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.

  In the above general formulas (Va), (Vb), and (Vc), the group of ring A1 and ring A1 ′ is preferably, for example, phenyl group, biphenyl group, naphthyl group, anthryl group, thienyl group, furyl group, benzo Examples include thienyl group, benzofuryl group, pyridyl group, quinolyl group, isoquinolyl group, carbazolyl group and the like.

  In addition, the group of ring A2 and ring A2 ′ is preferably a pyridyl group, pyrimidyl group, pyrazyl group, triazyl group, benzothiazole group, benzoxazole group, benzimidazole group, quinolyl group, isoquinolyl group, quinoxalyl group, A phenanthridyl group and the like can be mentioned.

  Furthermore, the substituents that the compounds represented by the general formulas (Va), (Vb), and (Vc) may have include halogen atoms such as fluorine atoms; alkyl groups such as methyl groups and ethyl groups; vinyls Alkenyl groups such as methoxy groups; alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups and benzyloxy groups; dialkyls such as dimethylamino groups and diethylamino groups An amino group; a diarylamino group such as a diphenylamino group; a carbazolyl group; an acyl group such as an acetyl group; a haloalkyl group such as a trifluoromethyl group; a cyano group;

  When the said substituent is an alkyl group, the carbon number is 1 or more and 6 or less normally. Furthermore, when the substituent is an alkenyl group, the carbon number is usually 2 or more and 6 or less. When the substituent is an alkoxycarbonyl group, the carbon number is usually 2 or more and 6 or less. Further, when the substituent is an alkoxy group, the carbon number is usually 1 or more and 6 or less. Moreover, when a substituent is an aryloxy group, the carbon number is 6 or more and 14 or less normally. Furthermore, when the substituent is a dialkylamino group, the carbon number is usually 2 or more and 24 or less. When the substituent is a diarylamino group, the carbon number is usually 12 or more and 28 or less. Furthermore, when the substituent is an acyl group, the carbon number is usually 1 or more and 14 or less. Moreover, when a substituent is a haloalkyl group, the carbon number is 1 or more and 12 or less normally.

  These substituents may be connected to each other to form a ring. As a specific example, a substituent of the ring A1 and a substituent of the ring A2 are bonded, or a substituent of the ring A1 ′ and a substituent of the ring A2 ′ are bonded. Two fused rings may be formed. Examples of such a condensed ring group include a 7,8-benzoquinoline group.

  Among them, as a substituent of ring A1, ring A1 ′, ring A2 and ring A2 ′, more preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, a cyano group, a halogen atom, a haloalkyl group, a diarylamino group, a carbazolyl group Is mentioned.

In general formula (Va), (Vb), preferably as ^{M a, M b, M c} in (Vc), ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum or gold.

  Specific examples of the organometallic complex represented by the general formula (V), (Va), (Vb) or (Vc) are shown below, but are not limited to the following compounds (in the following, Ph is phenyl Represents a group).

Among the organometallic complexes represented by the general formulas (V), (Va), (Vb), and (Vc), in particular, as the ligand L and / or L ′, a 2-arylpyridine-based ligand, , 2-arylpyridine, a compound having an arbitrary substituent bonded thereto, and a compound having an arbitrary group condensed thereto are preferable.
In addition, compounds described in WO2005 / 019373 can also be used.

Next, the compound represented by the general formula (VI) will be described.
In the general formula (VI), M ^d represents a metal, and specific examples thereof include the metals described above as the metal selected from Groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum or gold is preferable, and divalent metals such as platinum and palladium are particularly preferable.

In the general formula (VI), R ⁹² and R ⁹³ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, or a carboxyl group. Represents an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group or an aromatic heterocyclic group.

Further, when T is carbon, R ⁹⁴ and R ⁹⁵ each independently represent a substituent represented by the same examples as R ⁹² and R ⁹³ . Further, as described above, when T is nitrogen, there is no R ⁹⁴ or R ⁹⁵ .

R ^{92 to} R ⁹⁵ may further have a substituent. In this case, the substituent which may further be present is not particularly limited, and any group can be used as the substituent.
Furthermore, R ^{92 to} R ⁹⁵ may be linked to each other to form a ring, and this ring may further have an arbitrary substituent.

  Specific examples (T-1, T-10 to T-15) of the organometallic complex represented by the general formula (VI) are shown below, but are not limited to the following exemplified compounds. In the following, Me represents a methyl group, and Et represents an ethyl group.

[3] Other components In the charge transport material composition of the present invention, particularly the charge transport material composition used as the composition for an organic electroluminescent device, in addition to the solvent and the light emitting material described above, if necessary, Various other solvents may be included. Examples of such other solvents include amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and dimethyl sulfoxide.
Moreover, various additives, such as a leveling agent and an antifoamer, may be included.

  In addition, when two or more layers are laminated by a wet film-forming method, in order to prevent these layers from being compatible with each other, a photo-curing resin or a thermosetting resin is used for the purpose of curing and insolubilizing after film formation. Can also be contained.

[4] Material concentration and blending ratio in charge transport material composition Charge transport material composition, particularly charge transport material in organic electroluminescent device composition, light emitting material and components which can be added as required (leveling agent, etc.) ) And the like are usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, still more preferably 0.5% by weight or more, and most preferably 1% by weight. %, Usually 80% by weight or less, preferably 50% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, and most preferably 20% by weight or less. If this concentration is below the lower limit, it is difficult to form a thick film when forming a thin film, and if it exceeds the upper limit, it may be difficult to form a thin film.

  In the charge transport material composition of the present invention, particularly the composition for an organic electroluminescence device, the light-emitting material / charge transport material weight mixing ratio is usually 0.1 / 99.9 or more, more preferably 0. 0.5 / 99.5 or more, more preferably 1/99 or more, most preferably 2/98 or more, usually 50/50 or less, more preferably 40/60 or less, still more preferably. Is 30/70 or less, most preferably 20/80 or less. If this ratio falls below the lower limit or exceeds the upper limit, the luminous efficiency may be significantly reduced.

[5] Method for Preparing Charge Transport Material Composition The charge transport material composition of the present invention, particularly the composition for an organic electroluminescent device, includes a charge transport material, a light emitting material, and a leveling agent or antifoam that can be added as necessary. It is prepared by dissolving a solute composed of various additives such as an agent in an appropriate solvent. In order to shorten the time required for the dissolution step and to keep the solute concentration in the composition uniform, the solute is usually dissolved while stirring the liquid. The dissolution step may be performed at room temperature, but when the dissolution rate is slow, it can be heated and dissolved. After completion of the dissolution step, a filtration step such as filtering may be performed as necessary.

[6] Properties and physical properties of the charge transport material composition (moisture concentration)
When an organic electroluminescent device is produced by forming a layer by a wet film forming method using the charge transport material composition (composition for an organic electroluminescent device) of the present invention, moisture is contained in the composition for organic electroluminescent device to be used. If present, moisture is mixed into the formed film and the uniformity of the film is impaired. Therefore, it is preferable that the water content in the charge transport material composition of the present invention, particularly the composition for organic electroluminescent elements, is as low as possible. . In general, since organic electroluminescent devices use many materials such as cathodes that deteriorate significantly due to moisture, when moisture is present in the charge transport material composition, moisture remains in the dried film. There is a possibility of deteriorating the characteristics of the element, which is not preferable.

  Specifically, the amount of water contained in the charge transport material composition of the present invention, particularly the organic electroluminescent device composition, is usually 1% by weight or less, preferably 0.1% by weight or less, more preferably 0.8%. 01% by weight or less.

  As a method for measuring the water concentration in the charge transport material composition, the method described in Japanese Industrial Standard “Method for Measuring Water of Chemical Products” (JIS K0068: 2001) is preferable. For example, the Karl Fischer reagent method (JIS K0211-1348). ) And the like.

(Uniformity)
The charge transport material composition of the present invention, particularly the composition for an organic electroluminescence device, is uniform at room temperature in order to improve stability in a wet film forming process, for example, ejection stability from a nozzle in an ink jet film forming method. It is preferably a liquid. The uniform liquid at normal temperature means that the composition is a liquid composed of a uniform phase and does not contain a particle component having a particle size of 0.1 μm or more in the composition.

(Physical properties)
Regarding the viscosity of the charge transport material composition of the present invention, particularly the composition for organic electroluminescence device, in the case of extremely low viscosity, for example, uneven coating surface due to excessive liquid film flow in the film forming process, Nozzle discharge failure or the like is likely to occur, and when the viscosity is extremely high, nozzle clogging or the like in the ink-jet film formation is likely to occur. For this reason, the viscosity at 25 ° C. of the composition of the present invention is usually 2 mPa · s or more, preferably 3 mPa · s or more, more preferably 5 mPa · s or more, and usually 1000 mPa · s or less, preferably 100 mPa · s or less. More preferably, it is 50 mPa · s or less.

  In addition, when the surface tension of the charge transport material composition of the present invention, particularly the composition for organic electroluminescent elements is high, the wettability of the film-forming liquid with respect to the substrate is lowered, the leveling property of the liquid film is poor, and when dried Therefore, the surface tension at 20 ° C. of the composition of the present invention is usually less than 50 mN / m, preferably less than 40 mN / m.

  Furthermore, when the vapor pressure of the charge transport material composition of the present invention, particularly the composition for organic electroluminescent elements, is high, problems such as changes in solute concentration due to evaporation of the solvent are likely to occur. For this reason, the vapor pressure at 25 ° C. of the composition of the present invention is usually 50 mmHg or less, preferably 10 mmHg or less, more preferably 1 mmHg or less.

[7] Method for Preserving Charge Transport Material Composition The charge transport material composition of the present invention is preferably filled in a container capable of preventing the transmission of ultraviolet rays, such as a brown glass bottle, and stored tightly. The storage temperature is usually −30 ° C. or higher, preferably 0 ° C. or higher, and usually 35 ° C. or lower, preferably 25 ° C. or lower.

[Organic electroluminescence device]
The organic electroluminescent device of the present invention has at least an anode, a cathode, and a light emitting layer sandwiched between the anode and the cathode on a substrate, and is wet-film-formed using the charge transport material composition of the present invention. It has a layer formed by the method or a layer containing the organic compound of the present invention. The layer formed by the wet film-forming method using the composition for charge transport material or the layer containing the organic compound may be any layer, but is particularly preferably a light emitting layer. Moreover, it is preferable that the layer formed by the wet film-forming method using this composition for charge transport materials, or the layer containing this organic compound is doped with the organometallic complex. As the organometallic complex, those exemplified as the light emitting material can be used.

  1 to 8 are schematic sectional views showing structural examples suitable for the organic electroluminescence device of the present invention. In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a light emitting layer, 5 represents an electron injection layer, and 6 represents a cathode.

[1] Substrate The substrate 1 serves as a support for the organic electroluminescent element, and quartz or glass plates, metal plates, metal foils, plastic films, sheets, and the like are used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may be deteriorated by the outside air that has passed through the substrate, which is not preferable. For this reason, a method of securing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also one of preferable methods.

[2] Anode An anode 2 is provided on the substrate 1. The anode 2 plays a role of hole injection into a layer on the light emitting layer side (such as the hole injection layer 3 or the light emitting layer 4).

  This anode 2 is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum, a metal oxide such as an oxide of indium and / or tin, a metal halide such as copper iodide, carbon black, or A conductive polymer such as poly (3-methylthiophene), polypyrrole, or polyaniline is used.

  In general, the anode 2 is often formed by sputtering, vacuum deposition, or the like. In addition, when forming an anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, or conductive polymer fine powder, an appropriate binder resin solution is used. The anode 2 can also be formed by dispersing and coating the substrate 1. Further, in the case of a conductive polymer, a thin film can be directly formed on the substrate 1 by electrolytic polymerization, or the anode 2 can be formed by applying a conductive polymer on the substrate 1 (Appl. Phys. Lett. 60, 2711, 1992).

The anode 2 usually has a single-layer structure, but it can also have a laminated structure made of a plurality of materials if desired.

  The thickness of the anode 2 varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably about 500 nm or less. When it may be opaque, the thickness of the anode 2 is arbitrary, and the anode 2 may be the same as the substrate 1. Furthermore, it is also possible to laminate different conductive materials on the anode 2 described above.

  The surface of the anode is treated with ultraviolet (UV) / ozone, oxygen plasma, or argon plasma for the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve hole injection. Is preferred.

[3] Hole Injection Layer Since the hole injection layer 3 is a layer that transports holes from the anode 2 to the light emitting layer 4, the hole injection layer 3 preferably contains a hole transporting compound.

  In the hole injection layer 3, a cation radical obtained by removing one electron from an electrically neutral compound accepts one electron from a nearby electrically neutral compound, whereby holes move. When the cation radical compound is not included in the hole injection layer 3 when the element is not energized, the cation radical of the hole transport compound is generated when the hole transport compound gives electrons to the anode 2 during energization, Holes are transported by transferring electrons between the cation radical and an electrically neutral hole transporting compound.

  When the hole injection layer 3 contains a cation radical compound, cation radicals necessary for hole transport are present at a concentration higher than that generated by oxidation by the anode 2, and the hole transport performance is improved. It is preferable that the hole injection layer 3 contains a cation radical compound. When an electrically neutral hole transporting compound is present in the vicinity of the cation radical compound, electrons are transferred smoothly, so that the hole injection layer 3 contains a cation radical compound and a hole transporting compound. Is more preferable.

  Here, the cation radical compound is a cation radical that is a chemical species obtained by removing one electron from a hole transporting compound, and an ionic compound composed of a counter anion, and already has holes (free carriers) that are easy to move. Yes.

  Further, by mixing an electron-accepting compound with the hole-transporting compound, one-electron transfer from the hole-transporting compound to the electron-accepting compound occurs, and the above-described cation radical compound is generated. For this reason, it is preferable that the hole injection layer 3 contains a hole transporting compound and an electron accepting compound.

  Summarizing the above preferred materials, the hole injection layer 3 preferably contains a hole transporting compound, and more preferably contains a hole transporting compound and an electron accepting compound. The hole injection layer 3 preferably contains a cation radical compound, and more preferably contains a cation radical compound and a hole transporting compound.

  Furthermore, the hole injection layer 3 may contain a binder resin that does not easily trap charges and a coating property improving agent as necessary.

  However, as the hole injection layer 3, a film is formed on the anode 2 by a wet film-forming method using only an electron-accepting compound or an electron-accepting compound and a hole-transporting compound. It is also possible to laminate the composition by coating or vapor deposition. In this case, a part or all of the charge transport material composition interacts with the electron-accepting compound, whereby the hole transport layer 10 having excellent hole injectability is formed as shown in FIGS.

(Hole transporting compound)
As the hole transporting compound, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferable.

  Examples of the hole transporting compound include aromatic amine compounds, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, and the like. Of these, aromatic amine compounds are preferred from the viewpoints of amorphousness and visible light transmittance.

  Of the aromatic amine compounds, aromatic tertiary amine compounds are particularly preferable. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine.

  The type of the aromatic tertiary amine compound is not particularly limited, but a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less (a polymerization organic compound in which repeating units are linked) is more preferable from the viewpoint of the surface smoothing effect.

  Preferable examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following general formula (VII).

（一般式（VII）中、Ａｒ^２１，Ａｒ^２２は各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表す。Ａｒ^２３〜Ａｒ^２５は、各々独立して、置換基を有していてもよい２価の芳香族炭化水素基、または置換基を有していてもよい２価の芳香族複素環基を表す。Ｙは、下記の連結基群の中から選ばれる連結基を表す。また、Ａｒ^２１〜Ａｒ^２５のうち、同一のＮ原子に結合する二つの基は互いに結合して環を形成してもよい。）

(In the general formula (VII), Ar ²¹ and Ar ²² each independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar ^{23 to} Ar ²⁵ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent aromatic heterocyclic group which may have a substituent. Y represents a linking group selected from the following group of linking groups, and among Ar ^{21 to} Ar ²⁵ , two groups bonded to the same N atom are bonded to each other to form a ring. May be.)

（上記各式中、Ａｒ^３１〜Ａｒ^４１は、各々独立して、置換基を有していてもよい芳香族炭化水素環、または置換基を有していてもよい芳香族複素環由来の１価または２価の基を表す。Ｒ^１０１およびＲ^１０２は、各々独立して、水素原子または任意の置換基を表す。）

(In the above formulas, Ar ^{31 to} Ar ⁴¹ are each independently 1 derived from an aromatic hydrocarbon ring which may have a substituent, or an aromatic heterocyclic ring which may have a substituent. And R ¹⁰¹ and R ¹⁰² each independently represents a hydrogen atom or an arbitrary substituent.

As Ar ^{21 to} Ar ²⁵ and Ar ^{31 to} Ar ⁴¹ , any monovalent or divalent group derived from any aromatic hydrocarbon ring or aromatic heterocyclic ring is applicable. These may be the same or different from each other. Moreover, you may have arbitrary substituents.

  Examples of the aromatic hydrocarbon ring include a 5- or 6-membered monocyclic ring or a 2-5 condensed ring. Specific examples include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring and the like.

  The aromatic heterocycle includes a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. Specific examples include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, Thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring , Synoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring and the like.

Moreover, as Ar < ²³ > -Ar < ²⁵ >, Ar < ³¹ > -Ar < ³⁵ >, Ar < ³⁷ > -Ar < ⁴⁰ >, the bivalent origin derived from the 1 type or 2 types or more of aromatic hydrocarbon ring and / or aromatic heterocycle which were illustrated above is shown. Two or more groups may be linked and used.

The group derived from the aromatic hydrocarbon ring and / or aromatic heterocycle of Ar ^{21 to} Ar ⁴¹ may further have a substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less. The type of the substituent is not particularly limited, and examples thereof include one or more selected from the following substituent group D.

[Substituent group D]
An alkyl group having usually 1 or more, usually 10 or less, preferably 8 or less, such as a methyl group or an ethyl group; an alkenyl group having usually 2 or more, usually 11 or less, preferably 5 or less, such as a vinyl group An alkynyl group having usually 2 or more, usually 11 or less, preferably 5 or less, such as an ethynyl group; an alkoxy having a carbon number of usually 1 or more, usually 10 or less, preferably 6 or less, such as a methoxy group or an ethoxy group; A group; an aryloxy group such as a phenoxy group, a naphthoxy group, a pyridyloxy group, etc., usually 4 or more, preferably 5 or more, usually 25 or less, preferably 14 or less; a carbon such as a methoxycarbonyl group or an ethoxycarbonyl group An alkoxycarbonyl group having a number of usually 2 or more, usually 11 or less, preferably 7 or less; a dimethylamino group, a diethylamino group or the like, and usually having 2 or more carbon atoms Usually 20 or less, preferably 12 or less dialkylamino group; diphenylamino group, ditolylamino group, N-carbazolyl group, etc., and usually diarylamino having 10 or more carbon atoms, preferably 12 or more, usually 30 or less, preferably 22 or less Group: an arylalkylamino group having 6 or more carbon atoms, preferably 7 or more, usually 25 or less, preferably 17 or less, such as a phenylmethylamino group; an acetyl group, a benzoyl group or the like, and usually having 2 or more carbon atoms, Usually an acyl group of 10 or less, preferably 7 or less; a halogen atom such as a fluorine atom or a chlorine atom; a haloalkyl group having a carbon number of usually 1 or more, usually 8 or less, preferably 4 or less, such as a trifluoromethyl group; An alkylthio group having 1 to 10 carbon atoms, preferably 6 or less, preferably 6 or less; An arylthio group having usually 4 or more, preferably 5 or more, usually 25 or less, preferably 14 or less, such as a ruthio group, a naphthylthio group, or a pyridylthio group; Or more, preferably 3 or more, usually 33 or less, preferably 26 or less silyl group; trimethylsiloxy group, triphenylsiloxy group, etc., the carbon number is usually 2 or more, preferably 3 or more, usually 33 or less, preferably 26 or less. A siloxy group; a cyano group; an aromatic hydrocarbon ring group having usually 6 or more, usually 30 or less, preferably 18 or less, such as a phenyl group or a naphthyl group; a carbon number such as a thienyl group or a pyridyl group. An aromatic heterocyclic group of 3 or more, preferably 4 or more, usually 28 or less, preferably 17 or less.

Ar ²¹ and Ar ²² are preferably monovalent groups derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, or a pyridine ring from the viewpoint of the solubility, heat resistance, and hole injection / transport properties of the polymer compound. More preferred are a phenyl group and a naphthyl group.

Ar ^{23 to} Ar ²⁵ are preferably divalent groups derived from a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring from the viewpoint of heat resistance and hole injection / transport properties including redox potential. More preferably a group, a biphenylene group, or a naphthylene group.

As R ¹⁰¹ and R ¹⁰² , a hydrogen atom or an arbitrary substituent is applicable. These may be the same or different from each other. The type of the substituent is not particularly limited, and examples of applicable substituents include alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, silyl groups, siloxy groups, aromatic hydrocarbon groups, aromatic heterocyclic rings. Group and halogen atom. Specific examples thereof include the groups exemplified in the above substituent group D.

  Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the general formula (VII) include those described in WO 2005/089024, and suitable examples thereof are also the same. Although the compound (PB-1) represented by a formula is mentioned, it is not limited to them at all.

  Preferable examples of the other aromatic tertiary amine polymer compounds include polymer compounds containing a repeating unit represented by the following general formula (VIII) and / or general formula (IX).

（一般式（VIII）、（IX）中、Ａｒ^４５，Ａｒ^４７およびＡｒ^４８は各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表す。Ａｒ^４４およびＡｒ^４６は各々独立して、置換基を有していてもよい２価の芳香族炭化水素基、または置換基を有していてもよい２価の芳香族複素環基を表す。また、Ａｒ^４５〜Ａｒ^４８のうち、同一のＮ原子に結合する２つの基は互いに結合して環を形成してもよい。Ｒ^１１１〜Ｒ^１１３は各々独立して、水素原子または任意の置換基を表す。）

(In the general formulas (VIII) and (IX), Ar ⁴⁵ , Ar ⁴⁷ and Ar ⁴⁸ may each independently have an aromatic hydrocarbon group which may have a substituent, or a substituent. And each of Ar ⁴⁴ and Ar ⁴⁶ independently represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent which may have a substituent. In addition, two groups bonded to the same N atom among Ar ^{45 to} Ar ⁴⁸ may be bonded to each other to form a ring, and R ^{111 to} R ¹¹³ are each independently And represents a hydrogen atom or an arbitrary substituent.)

Specific examples of Ar ⁴⁵ , Ar ⁴⁷ , Ar ⁴⁸ and Ar ⁴⁴ , Ar ⁴⁶ , preferred examples, examples of substituents that may be included and examples of preferred substituents are Ar ²¹ , Ar ^22, and Ar ²³ ˜ Same as Ar ²⁵ . R ^{111 to} R ¹¹³ are preferably a hydrogen atom or a substituent described in [Substituent group D], more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, an aromatic hydrocarbon group, It is an aromatic hydrocarbon group.

  Specific examples of the aromatic tertiary amine polymer compound containing the repeating unit represented by the general formula (VIII) and / or (IX) include those described in WO 2005/089024, and preferred examples thereof are also the same. However, it is not limited to them.

  Moreover, when forming a positive hole injection layer with a wet film forming method, the positive hole transport compound which is easy to melt | dissolve in a various solvent is preferable. As the aromatic tertiary amine compound, for example, a binaphthyl compound (Japanese Patent Laid-Open No. 2004-014187) and an asymmetric 1,4-phenylenediamine compound (Japanese Patent Laid-Open No. 2004-026732) are preferable.

  In addition, compounds that are easily soluble in various solvents may be appropriately selected from aromatic amine compounds that have been conventionally used as a hole injection / transport thin film purification material in organic electroluminescent devices. Examples of the aromatic amine compound applicable to the hole-transporting compound of the hole-injecting layer include conventionally known compounds that have been utilized as a hole-injecting / transporting layer-forming material in organic electroluminescence devices. It is done. For example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (JP 59-194393 A); 4,4′- An aromatic amine compound containing two or more tertiary amines represented by bis [N- (1-naphthyl) -N-phenylamino] biphenyl and having two or more condensed aromatic rings substituted with nitrogen atoms No. 5-23481); an aromatic triamine compound having a starburst structure as a derivative of triphenylbenzene (US Pat. No. 4,923,774); N, N′-diphenyl-N, N′-bis (3- Aromatic diamine compounds such as methylphenyl) biphenyl-4,4′-diamine (US Pat. No. 4,764,625); α, α, α ′, α′-tetramethyl-α, α′- (4-di (p-tolyl) aminophenyl) -p-xylene (Japanese Patent Laid-Open No. 3-269084); sterically asymmetric triphenylamine derivative as a whole molecule (Japanese Patent Laid-Open No. 4-129271); pyrenyl A compound in which a plurality of aromatic diamino groups are substituted on the group (Japanese Patent Laid-Open No. 4-175395); an aromatic diamine compound in which a tertiary aromatic amine unit is linked with an ethylene group (Japanese Patent Laid-Open No. 4-264189); a styryl structure An aromatic diamine having a thiophene group (JP-A-4-290851); a compound in which an aromatic tertiary amine unit is linked by a thiophene group (JP-A-4-304466); a starburst type aromatic triamine compound (JP-A-4-30481) 308688); benzylphenyl compound (Japanese Patent Laid-Open No. 4-364153); Compounds in which thiones are linked (JP-A-5-25473); triamine compounds (JP-A-5-239455); bisdipyridylaminobiphenyl (JP-A-5-320634); N, N, N-triphenylamine Derivatives (JP-A-6-1972); Aromatic diamines having a phenoxazine structure (JP-A-7-138562); Diaminophenylphenanthridine derivatives (JP-A-7-252474); 2-311591); silazane compounds (US Pat. No. 4,950,950); silanamine derivatives (JP-A-6-49079); phosphamine derivatives (JP-A-6-25659); quinacridone compounds, etc. Can be mentioned. These aromatic amine compounds may be used in combination of two or more as required.

  Preferred specific examples of the phthalocyanine derivative or porphyrin derivative applicable to the hole transporting compound of the hole injection layer include porphyrin, 5,10,15,20-tetraphenyl-21H, 23H-porphyrin, 5,10 , 15,20-tetraphenyl-21H, 23H-porphyrin cobalt (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin copper (II), 5,10,15,20-tetraphenyl- 21H, 23H-porphyrin zinc (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin vanadium (IV) oxide, 5,10,15,20-tetra (4-pyridyl) -21H, 23H -Porphyrin, 29H, 31H-phthalocyanine copper (II), phthalocyanine zinc (II), Russia Nin titanium, phthalocyanine oxide magnesium, phthalocyanine lead, phthalocyanine copper (II), 4,4 ', 4 ", 4' '' - tetraaza-29H, 31H-phthalocyanine, and the like.

  Further, preferred specific examples of the oligothiophene derivative applicable as the hole transporting compound of the hole injection layer include α-terthiophene and its derivatives, α-sexithiophene and its derivatives, and oligothiophene containing a naphthalene ring. Derivatives (JP-A-6-256341) and the like.

  Further, preferred specific examples of the polythiophene derivative applicable as the hole transporting compound in the present invention include poly (3,4-ethylenedioxythiophene) (PEDOT), poly (3-hexylthiophene) and the like.

  The molecular weight of these hole transporting compounds is usually 9000 or less, preferably 5000 or less, and usually 200 or more, preferably 400 or more, except in the case of a polymer compound (a polymerizable compound in which repeating units are continuous). Range. If the molecular weight of the hole transporting compound is too high, synthesis and purification are difficult, which is not preferable. On the other hand, if the molecular weight is too low, the heat resistance may be lowered, which is also not preferable.

  The hole transporting compound used as the material for the hole injection layer may contain any one of these compounds alone, or may contain two or more. When two or more hole transporting compounds are contained, the combination thereof is arbitrary, but one or more aromatic tertiary amine polymer compounds and one or two other hole transporting compounds are used. It is preferable to use the above together.

(Electron-accepting compound)
The electron-accepting compound is preferably a compound having an oxidizing power and the ability to accept one electron from the above-described hole transporting compound, specifically, a compound having an electron affinity of 4 eV or more is preferable, and 5 eV or more. The compound which is the compound of these is further more preferable.

  Examples include onium salts substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, iron (III) chloride (JP-A-11-251067), ammonium peroxodisulfate and the like. Examples thereof include valent inorganic compounds, cyano compounds such as tetracyanoethylene, aromatic boron compounds such as tris (pentafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-31365), fullerene derivatives, iodine and the like.

  Of the above compounds, onium salts substituted with organic groups and high valent inorganic compounds are preferred because of their strong oxidizing power, and organic groups are substituted because they are soluble in various solvents and applicable to wet coating. Preferred are onium salts, cyano compounds, and aromatic boron compounds.

  Specific examples of the onium salt substituted with an organic group, cyano compound, and aromatic boron compound suitable as an electron-accepting compound include those described in WO 2005/089024, and the preferred examples thereof are also the same. Although the compound (A-2) represented by Structural Formula is mentioned, it is not limited to them at all.

(Cation radical compound)
The cation radical compound is an ionic compound composed of a cation radical which is a chemical species obtained by removing one electron from a hole transporting compound and a counter anion. However, when the cation radical is derived from a hole transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

  The cation radical is preferably a chemical species obtained by removing one electron from the aforementioned compound in the hole transporting compound, and is preferably a chemical species obtained by removing one electron from a compound more preferable as the hole transporting compound. From the viewpoints of visible light transmittance, heat resistance, solubility, and the like.

  The cation radical compound can be generated by mixing the hole transporting compound and the electron accepting compound. That is, by mixing the hole transporting compound and the electron accepting compound, electron transfer occurs from the hole transporting compound to the electron accepting compound, and the cation radical and the counter anion of the hole transporting compound are included. A cation ion compound is formed.

  Cationic radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, 12, 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, 94, 7716) It is also generated by oxidative polymerization (dehydrogenation polymerization), that is, by oxidizing a monomer chemically or electrochemically with peroxodisulfate in an acidic solution. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomer is oxidized to be polymerized, and the cation radical is formed by removing one electron from the repeating unit of the polymer with an anion derived from an acidic solution as a counter anion. Produces.

  The hole injection layer 3 is formed on the anode 2 by a wet film forming method or a vacuum deposition method.

  ITO (indium tin oxide), which is generally used as the anode 2, has a surface roughness of about 10 nm (Ra) and, in addition, often has protrusions locally, resulting in short-circuit defects. There was a problem that it was easy to produce. When the hole injection layer 3 formed on the anode 2 is formed by the wet film forming method, the generation of device defects due to the unevenness of the surface of the anode as compared with the case of forming by the vacuum deposition method. Has the advantage of reducing.

  In the case of layer formation by the wet film-forming method, a predetermined amount of one or more of the aforementioned materials (hole transporting compound, electron accepting compound, cation radical compound) does not become a charge trap if necessary. Add binder resin and coatability improver, dissolve in solvent, prepare coating solution, by wet film forming method such as spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, inkjet method etc. It is applied on the anode and dried to form the hole injection layer 3.

  As the solvent used for the layer formation by the wet film forming method, any solvent can be used as long as it can dissolve the above-mentioned materials (hole transporting compound, electron accepting compound, cation radical compound). Is not particularly limited, but generates a deactivated substance or deactivated substance that may deactivate each material (hole transporting compound, electron accepting compound, cation radical compound) used in the hole injection layer The thing which does not contain is preferable.

  Preferred solvents that satisfy these conditions include, for example, ether solvents and ester solvents. Specifically, examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1, 3 -Aromatic ethers such as dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole and the like. Examples of the ester solvent include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and benzoic acid. Examples include aromatic esters such as n-butyl. Any one of these may be used alone, or two or more thereof may be used in any combination and ratio.

  Examples of solvents that can be used in addition to the ether solvents and ester solvents described above include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and amides such as N, N-dimethylformamide and N, N-dimethylacetamide. System solvents, dimethyl sulfoxide and the like. Any one of these may be used alone, or two or more thereof may be used in any combination and ratio. Moreover, you may use 1 type (s) or 2 or more types among these solvents in combination with 1 type (s) or 2 or more types among the above-mentioned ether solvent and ester solvent. In particular, aromatic hydrocarbon solvents such as benzene, toluene, and xylene have a low ability to dissolve electron accepting compounds and cation radical compounds, and therefore are preferably mixed with ether solvents and ester solvents.

  The concentration of the solvent in the coating solution is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, and usually 99.999% by weight or less, preferably 99.99% by weight or less. Preferably it is the range of 99.9 weight% or less. When two or more kinds of solvents are mixed and used, the total of these solvents is set to satisfy this range.

In the case of forming a layer by vacuum deposition, one or more of the aforementioned materials (hole transporting compound, electron accepting compound, cation radical compound) are put in a crucible installed in a vacuum vessel ( When two or more materials are used, put them in each crucible), and after evacuating the inside of the vacuum vessel to about 10 ⁻⁴ Pa with an appropriate vacuum pump, heat the crucible (if using two or more materials, each Heat the crucible) and evaporate by controlling the amount of evaporation (if more than one material is used, evaporate by controlling the amount of evaporation independently) and place it positively on the anode of the substrate placed facing the crucible A hole injection layer is formed. In addition, when using 2 or more types of materials, they can also be put into a crucible, can be heated and evaporated, and can be used for hole injection layer formation.

The film thickness of the hole injection layer 3 that may be formed in this manner is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.
The hole injection layer 3 may be omitted as shown in FIG.

[4] Light-Emitting Layer A normal light-emitting layer 4 is provided on the hole injection layer 3. The light emitting layer 4 is a layer containing a light emitting material, and between the electrodes to which an electric field is applied, holes injected from the anode 2 through the hole injection layer 3 and electrons injected from the cathode 6 through the electron transport layer 5 It is a layer that is excited by recombination and becomes a main light emitting source. The light-emitting layer 4 preferably contains a light-emitting material (dopant) and one or more host materials, and the light-emitting layer 4 more preferably contains the charge transport material of the present invention as a host material, and is formed by a vacuum deposition method. However, it is particularly preferable that the layer be prepared by a wet film forming method using the charge transport material composition of the present invention.

  Here, the wet film forming method is a method of forming a film by applying the charge transporting material composition of the present invention containing the above solvent by spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, or ink jet method. Is.

  In addition, the light emitting layer 4 may contain other materials and components as long as the performance of the present invention is not impaired.

  In general, in the organic electroluminescence device, when the same material is used, the thinner the film thickness between the electrodes is, the larger the effective electric field is. For this reason, the driving voltage of the organic electroluminescence device decreases when the total film thickness between the electrodes is thin, but if it is too thin, a short circuit occurs due to the protrusion caused by the electrode such as ITO. Necessary.

  In the present invention, in addition to the light emitting layer 4, when the organic layer such as the hole injection layer 3 and the electron transport layer 5 described later is provided, the light emitting layer 4 and other organic materials such as the hole injection layer 3 and the electron transport layer 5 are used. The total film thickness combined with the layer is usually 30 nm or more, preferably 50 nm or more, more preferably 100 nm or more, usually 1000 nm or less, preferably 500 nm or less, more preferably 300 nm or less. In addition, when the conductivity of the hole injection layer 3 other than the light emitting layer 4 and the electron injection layer 5 described later is high, the amount of charge injected into the light emitting layer 4 increases. It is also possible to reduce the drive voltage while increasing the thickness to reduce the thickness of the light emitting layer 4 and maintaining the total thickness to some extent.

  Therefore, the thickness of the light emitting layer 4 is usually 10 nm or more, preferably 20 nm or more, and usually 300 nm or less, preferably 200 nm or less. When the element of the present invention has only the light emitting layer 4 between the anode and the cathode, the thickness of the light emitting layer 4 is usually 30 nm or more, preferably 50 nm or more, usually 500 nm or less, preferably 300 nm or less. is there.

[5] Electron Injection Layer The electron injection layer 5 plays a role of efficiently injecting electrons injected from the cathode 6 into the light emitting layer 4. In order to perform electron injection efficiently, the material for forming the electron injection layer 5 is preferably a metal having a low work function, and alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium are used.
The film thickness of the electron injection layer 5 is preferably 0.1 to 5 nm.

Alternatively, an ultrathin insulating film (0.1 to 5 nm) such as LiF, MgF ₂ , Li ₂ O, or CsCO ₃ may be inserted at the interface between the cathode 6 and the light emitting layer 4 or the electron transport layer 8 described later. (Appl. Phys. Lett., 70, 152, 1997; JP-A-10-74586; IEEE Trans. Electron. Devices, 44, 1245, 1997) SID 04 Digest, page 154).

  Further, organic electron transport materials represented by metal complexes such as nitrogen-containing heterocyclic compounds such as bathophenanthroline and aluminum complexes of 8-hydroxyquinoline described later are doped with alkali metals such as sodium, potassium, cesium, lithium and rubidium. (Described in JP-A-10-270171, JP-A 2002-1000047, JP-A 2002-1000048, and the like) makes it possible to improve electron injection / transport properties and achieve excellent film quality. Therefore, it is preferable. The film thickness in this case is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer 5 is formed by laminating on the light emitting layer 4 by a wet film forming method or a vacuum deposition method in the same manner as the light emitting layer 4. In the case of the vacuum evaporation method, the evaporation source is put into a crucible or metal boat installed in a vacuum vessel, and the inside of the vacuum vessel is evacuated to about 10 ⁻⁴ Pa with an appropriate vacuum pump, and then the crucible or metal boat is Heat and evaporate to form an electron injection layer on the substrate placed facing the crucible or metal boat.

The alkali metal is deposited using an alkali metal dispenser in which nichrome is filled with an alkali metal chromate and a reducing agent. By heating the dispenser in a vacuum container, the alkali metal chromate is reduced and the alkali metal is evaporated. In the case of co-evaporating the organic electron transport material and the alkali metal, the organic electron transport material is put in a crucible installed in a vacuum vessel, and the inside of the vacuum vessel is evacuated to about 10 ⁻⁴ Pa with a suitable vacuum pump. Each crucible and dispenser are heated simultaneously to evaporate to form an electron injection layer on the substrate placed facing the crucible and dispenser.

At this time, co-evaporation is uniformly performed in the film thickness direction of the electron injection layer 5, but there may be a concentration distribution in the film thickness direction.
The electron injection layer 5 may be omitted as shown in FIGS.

[6] Cathode The cathode 6 plays a role of injecting electrons into a layer on the light emitting layer side (such as the electron injection layer 5 or the light emitting layer 4). The material used for the cathode 6 can be the material used for the anode 2, but a metal having a low work function is preferable for efficient electron injection, such as tin, magnesium, indium, calcium, A suitable metal such as aluminum or silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

  The film thickness of the cathode 6 is usually the same as that of the anode 2. For the purpose of protecting the cathode made of a low work function metal, further laminating a metal layer having a high work function and stable to the atmosphere on the cathode increases the stability of the device. For this purpose, metals such as aluminum, silver, copper, nickel, chromium, gold, platinum are used.

[7] Other Constituent Layers While the description has been given centering on the element having the layer constitution shown in FIG. 1, the performance between the anode 2 and the cathode 6 and the light emitting layer 4 in the organic electroluminescent element of the present invention is described. In addition to the layers described above, any layer may be included, and any layer other than the light emitting layer 4 may be omitted.

  Examples of the layer that may be included include the electron transport layer 7. The electron transport layer 7 is provided between the light emitting layer 4 and the electron injection layer 5 as shown in FIG. 2 for the purpose of further improving the light emission efficiency of the device.

  The electron transport layer 7 is formed of a compound capable of efficiently transporting electrons injected from the cathode 6 between electrodes to which an electric field is applied in the direction of the light emitting layer 4. As an electron transport compound used for the electron transport layer 7, the electron injection efficiency from the cathode 6 or the electron injection layer 5 is high, and the injected electrons can be efficiently transported with high electron mobility. It must be a compound.

  Materials satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives, Styryl biphenyl derivative, silole derivative, 3- or 5-hydroxyflavone metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compound No. 207169), phenanthroline derivatives (Japanese Patent Laid-Open No. 5-331459), 2-t-butyl-9,10-N, N′-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide, n-type sulfide Examples include zinc and n-type zinc selenide.

  The lower limit of the thickness of the electron transport layer 7 is usually 1 nm, preferably about 5 nm, and the upper limit is usually about 300 nm, preferably about 100 nm.

  The electron transport layer 7 is formed by laminating on the light emitting layer 4 by a wet film forming method or a vacuum deposition method in the same manner as the hole injection layer 3. Usually, a vacuum deposition method is used.

  Moreover, it is preferable in this invention to have the positive hole transport layer 10, and the compound illustrated as a positive hole transportable compound of the said positive hole injection layer can also be used. Alternatively, a polymer material such as polyarylene ether sulfone containing polyvinyl carbazole, polyvinyl triphenylamine, or tetraphenylbenzidine may be used. The hole transport layer 10 is formed by laminating these materials on the hole injection layer by a wet film formation method or a vacuum deposition method. The film thickness of the hole transport layer 10 thus formed is usually 10 nm or more, preferably 30 nm. However, it is usually 300 nm or less, preferably 100 nm or less.

  In particular, when a phosphorescent material or a blue light emitting material is used as the light emitting substance, it is also effective to provide the hole blocking layer 8 as shown in FIG. The hole blocking layer 8 has a function of confining holes and electrons in the light emitting layer 4 and improving luminous efficiency. That is, the hole blocking layer 8 is generated by blocking the holes moving from the light emitting layer 4 from reaching the electron transport layer 7, thereby increasing the recombination probability with electrons in the light emitting layer 4. There is a role of confining excitons in the light emitting layer 4 and a role of efficiently transporting electrons injected from the electron transport layer 8 toward the light emitting layer 4.

  The hole blocking layer 8 prevents the holes moving from the anode 2 from reaching the cathode 6 and can efficiently transport the electrons injected from the cathode 6 toward the light emitting layer 4. The compound is laminated on the light emitting layer 4 so as to be in contact with the interface of the light emitting layer 4 on the cathode 6 side.

  The physical properties required for the material constituting the hole blocking layer 8 include high electron mobility, low hole mobility, a large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). Is high.

  Examples of the hole blocking layer material satisfying such conditions include mixed arrangements of bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanolato) aluminum, and the like. Ligand complexes, metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives ( JP-A-11-242996), triazole derivatives such as 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (JP-A-7-41759) And phenanthroline derivatives such as bathocuproine (Japanese Patent Laid-Open No. 10-79297).

  Furthermore, a compound having at least one pyridine ring substituted at the 2,4,6-positions described in WO2005 / 022962 is also preferable as the hole blocking material.

  The film thickness of the hole blocking layer 8 is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

  The hole blocking layer 8 can also be formed by the same method as the hole injection layer 3, but a vacuum deposition method is usually used.

  The electron transport layer 7 and the hole blocking layer 8 may be appropriately provided as necessary. 1) Only the electron transport layer, 2) Only the hole blocking layer, 3) Lamination of the hole blocking layer / electron transport layer, 4) There are usages such as not using. Further, as shown in FIG. 7, the electron injection layer 5 may be omitted and the hole blocking layer 8 and the electron transport layer 7 may be laminated, or only the electron transport layer 7 may be used as shown in FIG.

  For the same purpose as the hole blocking layer 8, it is also effective to provide an electron blocking layer 9 between the hole injection layer 3 and the light emitting layer 4 as shown in FIG. The electron blocking layer 9 increases the probability of recombination with holes in the light emitting layer 4 by blocking the electrons moving from the light emitting layer 4 from reaching the hole injection layer 3, thereby generating excitons generated. Has a role of confining the light in the light emitting layer 4 and a role of efficiently transporting holes injected from the hole injection layer 3 in the direction of the light emitting layer 4.

  The characteristics required for the electron blocking layer 9 include high hole transportability, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1). Further, when the light emitting layer 4 is formed by a wet film forming method, it is preferable that the electron blocking layer 9 is also formed by a wet film forming method because the device manufacturing becomes easy.

  For this reason, it is preferable that the electron blocking layer 9 also has wet film forming compatibility. As a material used for such an electron blocking layer 9, a copolymer of dioctylfluorene and triphenylamine typified by F8-TFB is used. (Described in WO 2004/084260).

  The structure opposite to that shown in FIG. 1, that is, the cathode 6, the electron injection layer 5, the light emitting layer 4, the hole injection layer 3, and the anode 2 can be laminated on the substrate 1 in this order. It is also possible to provide the organic electroluminescent element of the present invention between two substrates, at least one of which is highly transparent. Similarly, it is also possible to laminate in a structure opposite to the above-described respective layer configurations shown in FIGS.

Furthermore, a structure in which a plurality of layers shown in FIG. 1 are stacked (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interfacial layer (between the light emitting units) (when the anode is ITO and the cathode is Al, the two layers), for example, V ₂ O ₅ is used as the charge generation layer (CGL). This is more preferable from the viewpoint of luminous efficiency and driving voltage.

  The present invention can be applied to any of an organic electroluminescent element having a single element, an element having a structure arranged in an array, and a structure having an anode and a cathode arranged in an XY matrix.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

(Example 1)

In a nitrogen stream, 2,8-diiododibenzo [b, d] furan (2.52 g), benzanilide (3.60 g), copper iodide (0.68 g), tripotassium phosphate (5.09 g), and N, N′-dimethylethylenediamine (0.8 ml) was added to room temperature while stirring anhydrous 1,4-dioxane (45 ml), and the mixture was stirred for 23 hours while heating under reflux. After adding ethyl acetate (120 ml) to this, activated clay was added and stirred. This was filtered, and the filtrate was concentrated and purified by silica gel column chromatography, suspension washing with a hexane / ethanol mixed solvent, and distillation under high vacuum to obtain the desired product (IA) (2.26 g). It was.
It was confirmed by DEI-MS m / z = 558 (M ⁺ ) that it was the target product.
This had a glass transition temperature of 93 ° C., a crystallization temperature of 158 ° C., a melting point of 200 ° C., and a vaporization temperature of 426 ° C. The triplet excitation energy level was 418 nm.

(Example 2)

  In a nitrogen stream, palladium acetate (0.40 g), tri-t-butylphosphine (1.51 g), and dehydrated toluene (80 ml) were added, and the mixture was stirred at 50 ° C. for 30 minutes. M-Phenylbromocarbazole (9.66 g), aniline (3.49 g) and sodium t-butoxy (17.2 g) were added to this system, and the mixture was stirred at 100 ° C. for 7 hours. After extraction and washing with dichloromethane and Brine, the organic layer was dried over sodium sulfate, and then dichloromethane was distilled off under reduced pressure. Purification by column chromatography gave the target amine compound (II-a) as a white powder (3.01 g).

In a nitrogen stream, the amine compound (II-a) (2.66 g) and 30 ml of dehydrated ether were added, and the mixture was cooled to −70 ° C. in a dry ice bath. To this, a 1.58 mol / l hexane solution (5.53 ml) of n-butyllithium was slowly added, stirred for 30 minutes, then slowly warmed to room temperature, and further stirred for 1 hour. After cooling again with a dry ice bath, a solution of isophthalic acid chloride (0.72 g) saturated with ether was slowly added. After stirring for 30 minutes, the mixture was diluted with dichloromethane, poured into ice, and neutralized with concentrated hydrochloric acid to pH 7. Extraction with dichloromethane, drying with sodium sulfate, and evaporation under reduced pressure gave a brown oil. This was purified by column chromatography to obtain the target compound (II-A) (2.7 g).
It was confirmed by DEI-MS m / z = 780 (M ⁺ ) that it was the target product.
This had a glass transition temperature of 86 ° C. and a vaporization temperature of 488 ° C. The triplet excitation energy level was 411 nm.
Further, the solubility (saturated solubility) in toluene was 10.5% by weight, and the solubility in ethanol was <0.1% by weight.

(Example 3)

  In a nitrogen stream, 9-phenylcarbazole (3.16 g), potassium iodide (3.02 g), and acetic acid (40 ml) were added and heated to 120 ° C. to make a homogeneous solution. After cooling to 65 ° C., potassium periodate (3.89 g) was added and stirred for 4 hours. Water was added to precipitate a white powder, which was filtered off and recrystallized from acetone to obtain the target compound (Ib) (5 g).

In a nitrogen stream, compound (Ib) (1.1 g), benzanilide (1.1 g), copper iodide (0.21 g), N, N′-dimethylethylenediamine (0.19 g), potassium triphosphate ( 1.4 g) and dimethoxyethane (30 ml) were added, and the mixture was heated and stirred for 24 hours. Extraction washing was carried out with dichloromethane and Brine, and the organic layer was dried over sodium sulfate and then distilled off under reduced pressure to obtain a brown oil. This was purified by column chromatography to obtain the target compound (IB) (0.8 g).
It was confirmed by DEI-MS m / z = 635 (M ⁺ ) that it was the target product.
This had a glass transition temperature of 113 ° C. and a vaporization temperature of 458 ° C. The triplet excitation energy level was 427 nm.
Moreover, the solubility with respect to toluene was 12 weight%, and the solubility with respect to ethanol was 1.5 weight%.

Example 4

  In a nitrogen stream, benzanilide (2.95 g), 1,3-diiodobenzene (9.90 g), copper iodide (0.28 g), N, N′-dimethylethylenediamine (0.26 g), potassium triphosphate (6.34 g) and dioxane (60 ml) were added, and the mixture was heated to reflux for 6 hours. Insoluble matter was removed by filtration, and dioxane was distilled off under reduced pressure to obtain a brown oil. This was purified by column chromatography to obtain the target compound (II-b1) (1.8 g).

  The target compound (II-b2) was obtained by reacting isophthalic acid chloride with aniline.

  In a nitrogen stream, compound (II-b1) (1.73 g), compound (II-b2) (0.62 g), copper iodide (0.12 g), N, N′-dimethylethylenediamine (0.03 g), Potassium triphosphate (1.66 g) and dioxane (40 ml) were added, and the mixture was heated to reflux for 40 hours. Insoluble matters were removed by filtration, extraction and washing were performed with chloroform and Brine, and the organic layer was dried over sodium sulfate. After distillation under reduced pressure, the obtained brown oil was purified by column chromatography to obtain the target compound (II-B) (0.4 g).

By DEI-MS m / z = 860 (M ^<+> ), it confirmed that it was the target object.
This had a glass transition temperature of 82 ° C. and a vaporization temperature of 468 ° C.
Moreover, the solubility with respect to toluene was 11.0 weight%, and the solubility with respect to ethanol was 1.3 weight%.

(Example 5)
An organic electroluminescent element having the structure shown in FIG. 7 was produced by the following method.
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate 1 having a thickness of 150 nm (sputtered film; sheet resistance 15 Ω) is patterned into a 2 mm wide stripe using normal photolithography and hydrochloric acid etching. Thus, an anode 2 was formed. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

The hole injection layer 3 was formed by a wet coating method as follows. As a material for the hole injection layer 3, a polymer compound having an aromatic amino group represented by the structural formula shown below (P-1 (weight average molecular weight: 29400, number average molecular weight: 12600)) and an electron having the structural formula shown below. Using the accepting compound (A-1), spin coating was performed under the following conditions.

<Spin coating conditions>
Solvent Ethyl benzoate Coating solution concentration P-1 2.0% by weight
A-1 0.4% by weight
Spinner speed 1500rpm
Spinner rotation time 30 seconds Drying conditions 230 ° C x 15 minutes

  A uniform thin film having a thickness of 30 nm was formed by the above spin coating.

Then, it formed by the vacuum evaporation method using the triphenylamine derivative (H-1) shown below as the positive hole transport layer 10. FIG. At this time, the temperature of the crucible of the triphenylamine derivative was set to 261 to 293 ° C., and the film was laminated with a film thickness of 40 nm at a deposition rate of 0.08 to 0.1 nm / second. The degree of vacuum at the time of vapor deposition was 1.4 to 1.3 × 10 ⁻⁴ Pa.

Subsequently, the light emitting layer 4 was deposited on the hole transport layer 10. The following compound (E-1) is used as a material for the light-emitting layer 4 together with an iridium complex (D-1) having the structural formula shown below, and the compound (E-1) is crucible at a temperature of 256 to 261 ° C. The iridium complex (D-1) was laminated to a thickness of 31.8 nm at a crucible temperature of 249 to 251 ° C. and a deposition rate of 0.006 nm / second. The degree of vacuum during vapor deposition was 1.3 to 1.2 × 10 ⁻⁴ Pa.

Next, a pyridine derivative (HB-1) shown below as the hole blocking layer 8 was laminated at a crucible temperature of 270 to 306 ° C. to a film thickness of 5 nm at a deposition rate of 0.08 nm / second. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa.

Next, an aluminum 8-hydroxyquinoline complex (ET-1) shown below was deposited as an electron transport layer 7 on the hole blocking layer 8 in the same manner. At this time, the crucible temperature of the aluminum 8-hydroxyquinoline complex (ET-1) is controlled in the range of 231 to 243 ° C., and the degree of vacuum during the deposition is 1.0 to 0.96 × 10 ⁻⁴ Pa, the deposition rate. Was 0.08 to 0.1 nm / second and the film thickness was 30 nm.

  The substrate temperature during vacuum deposition of the hole transport layer 4, the light emitting layer 5, the hole blocking layer 6 and the electron transport layer 7 was kept at room temperature.

Here, the element that has been deposited up to the electron transport layer 7 is once taken out from the vacuum deposition apparatus into the atmosphere, and a 2 mm wide striped shadow mask is used as a cathode deposition mask. The device was placed in close contact with each other so as to be orthogonal to each other, placed in another vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus was 2.3 × 10 ⁻⁴ Pa or less in the same manner as the organic layer.

As the cathode 9, first, lithium fluoride (LiF) is deposited using a molybdenum boat at a deposition rate of 0.008 to 0.02 nm / second, a degree of vacuum of 2.5 × 10 ⁻⁴ Pa, and a thickness of 0.5 nm. Then, a film was formed on the electron transport layer 7. Next, aluminum is similarly heated by a molybdenum boat to form an aluminum layer having a film thickness of 80 nm at a deposition rate of 0.1 to 0.12 nm / second and a degree of vacuum of 2.5 × 10 ⁻⁴ Pa. Completed. The substrate temperature at the time of vapor deposition of the above two-layered cathode 9 was kept at room temperature.

As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained. The light emission characteristics of this element are as follows.
Luminance / current: 29.3 [cd / A] @ 100 cd / m ²
Voltage: 4.8 [V] @ 100 cd / m ²
Luminous efficiency: 19.2 [1 m / w] @ 100 cd / m ²

  The maximum wavelength of the emission spectrum of the device was 512.8 nm, which was identified as that from the iridium complex (D-1). The chromaticity was CIE (x, y) = (0.303, 0.622).

(Example 6)
An organic electroluminescent element was produced in the same manner as in Example 1 except that the compound (E-2) shown below was used instead of the compound (E-1) as the material of the light emitting layer 4.

The light emission characteristics of this element are as follows.
Luminance / current: 19.9 [cd / A] @ 100 cd / m ²
Voltage: 6.6 [V] @ 100 cd / m ²
Luminous efficiency: 9.6 [1 m / w] @ 100 cd / m ²

  The maximum wavelength of the emission spectrum of the device was 512.8 nm, which was identified as that from the iridium complex (D-1). The chromaticity was CIE (x, y) = (0.296, 0.618).

(Example 7)
An organic electroluminescent element was produced in the same manner as in Example 1 except that the compound (E-3) shown below was used instead of the compound (E-1) as the material of the light emitting layer 5.

The light emission characteristics of this element are as follows.
Luminance / current: 22.7 [cd / A] @ 100 cd / m ²
Voltage: 6.2 [V] @ 100 cd / m ²
Luminous efficiency: 11.6 [1 m / w] @ 100 cd / m ²

  The maximum wavelength of the emission spectrum of the device was 511.5 nm, which was identified as from the iridium complex (D-1). The chromaticity was CIE (x, y) = (0.306, 0.615).

It is typical sectional drawing which showed an example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Light emitting layer 5 Electron injection layer 6 Cathode 7 Electron transport layer 8 Hole blocking layer 9 Electron blocking layer 10 Hole transport layer

Claims (10)

An organic compound represented by the following formula (I).

(In formula (I), Ar ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ^{1 to} R ⁶ are Each independently represents a hydrogen atom or an arbitrary substituent, Q ¹ represents a direct bond, an ether group, an alkylene group which may have a substituent, an amino group which may have a substituent, or a substituent; Represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and n represents an integer of 2 to 6.) The organic compound according to claim 1, wherein the formula (I) is represented by the following formula (I-1).

(In Formula (I-1), Ar ^1a and Ar ^1b have the same meaning as Ar ¹ in Formula (I). R ^{11 to} R ¹⁶ and R ^{21 to} R ²⁶ represent R ^{1 to} R in Formula (I). ⁶ synonymous .Q ¹ has the same meaning as in the formula (I).) In the above formula (I), Q ¹ is a linking group that does not conjugate n partial structures represented by the following formula (i) constituting the compound represented by the above formula (I). The organic compound according to 1 or 2.

An organic compound represented by the following formula (II).

(In formula (II), Ar ² represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ^{31 to} R ³³ are Each independently represents a hydrogen atom or an arbitrary substituent, m represents an integer of 1 to 6. When m is 1, the compound represented by formula (II) has an N = N bond. (In addition, in formula (II), the benzene ring to which the carbonyl group is bonded may have a substituent other than the carbonyl group.) The organic compound according to claim 4, wherein the formula (II) is represented by the following formula (II-1).

(In the formula (II-1), Ar ^2b and Ar ^2a is .R ⁴¹ to R ⁴⁶ are synonymous with Ar ² in the formula (II) has the same meaning as R ³¹ to R ³³ in formula (II). In addition, in the formula (II), the benzene ring to which two carbonyl groups are bonded may have a substituent other than the carbonyl group.)   A charge transport material comprising the organic compound according to any one of claims 1 to 5.   A composition for a charge transport material, comprising the organic compound according to any one of claims 1 to 5.   Furthermore, the composition for charge transport materials of Claim 7 containing a solvent.   An organic electroluminescent device having an anode, a cathode, and a light emitting layer sandwiched between the anode and the cathode on a substrate, using the composition for a charge transport material according to claim 7 or 8, by a wet film forming method. An organic electroluminescent device comprising a formed layer.   6. An organic electroluminescent device comprising an anode, a cathode, and a light emitting layer sandwiched between the anode and the cathode on a substrate, comprising an organic compound-containing layer according to any one of claims 1 to 5. Organic electroluminescent element characterized.

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