WO2012043774A1

WO2012043774A1 - Composition for organic electroluminescent element; organic electroluminescent element, charge transport layer, light-emitting layer, and film using said composition; method for forming light-emitting layer, and method for forming charge transport layer

Info

Publication number: WO2012043774A1
Application number: PCT/JP2011/072482
Authority: WO
Inventors: 林　直之; 佳奈山本
Original assignee: 富士フイルム株式会社
Priority date: 2010-09-30
Filing date: 2011-09-29
Publication date: 2012-04-05
Also published as: JP2013165089A; JP5645576B2

Abstract

A composition for an organic electroluminescent element in which an antioxidant agent capable of evaporating or decomposing by being heated is added to a liquid body containing an organic material and a solvent, wherein the antioxidant agent evaporates or decomposes by means of heat generated when forming the composition into a film during the process of producing an organic electroluminescent element. An organic electroluminescent element, charge transport layer, light-emitting layer, and film using the aforementioned composition, a method for forming a light-emitting layer, and a method for forming a charge transport layer.

Description

Composition for organic electroluminescent device, and film, light emitting layer, charge transport layer, organic electroluminescent device, method for forming light emitting layer, and method for forming charge transport layer using the composition

The present invention relates to a composition for an organic electroluminescent device, and a film, a light emitting layer, a charge transport layer, an organic electroluminescent device, a method for forming a light emitting layer, and a method for forming a charge transport layer using the composition.

Research has been actively conducted on devices using organic materials, such as organic electroluminescent elements (hereinafter also referred to as OLEDs and organic EL elements) and transistors using organic semiconductors. In particular, the organic electroluminescence device is expected to be developed as a lighting application as a solid light-emitting large-area full-color display device or an inexpensive large-area surface light source. In general, an organic electroluminescent element is composed of an organic layer including a light emitting layer and a pair of counter electrodes sandwiching the organic layer. When a voltage is applied to such an organic electroluminescence device, electrons are injected from the cathode and holes are injected from the anode into the organic layer. The electrons and holes recombine in the light emitting layer, and light is emitted by releasing energy as light when the energy level returns from the conduction band to the valence band.

An organic EL element can be produced by forming a light emitting layer and other organic layers by, for example, a dry method such as vapor deposition or a wet method such as coating. However, wet methods are attracting attention from the viewpoint of productivity. ing.
However, since a manufacturing process using a wet method such as coating is usually performed in an atmospheric environment, the liquid composition used in the wet method such as coating is manufactured or stored stably and formed into a film by the atmosphere (oxygen). However, problems such as a change in physical properties and a decrease in performance of an organic EL device produced using the composition due to the change in physical properties have arisen. For example, in the production of an organic EL element by coating, an organic EL element coating solution containing an organic material is coated and then heated and dried at 160 ° C. to oxidize the organic material. It has been confirmed that the oxygen concentration in the film increases.
In order to cope with such a problem, for example, Patent Document 1 adds an antioxidant to a liquid containing an organic functional material and a solvent, thereby suppressing a change in physical properties due to the atmosphere (oxygen), and a liquid composition. It discloses that the stability of things can be improved. Further, it is disclosed that an excellent device with high reliability can be provided by manufacturing various devices using such a liquid composition.
Further, in Patent Document 2, in an organic EL device containing a light emitting material and a hole transport material in the same or different organic layers, at least one of the organic layers containing the hole transport material contains an antioxidant and a light stabilizer. It is disclosed that an organic EL device having a long lifetime can be obtained by containing at least one of the agents and reducing attenuation of luminance and increase of driving voltage.

However, as the antioxidant used in the invention of Patent Document 1, specifically described phenolic antioxidants, sulfur-based antioxidants and phosphoric acid-based antioxidants, and in Examples of Patent Document 2 None of the phenolic antioxidants, hindered amine light stabilizers and benzophenone light stabilizers used are those that are not evaporated or decomposed by heating during film formation of the composition in the production of organic EL elements. The antioxidant and the light stabilizer remain in the film after film formation. These antioxidants and light stabilizers are insulators or compounds with extremely low mobility, and adversely affect carrier mobility, so that they remain in the film, thereby reducing the organic EL device performance such as external quantum efficiency. Is known and needs improvement.

Japanese Unexamined Patent Publication No. 2004-88094 Japanese Patent No. 3944274 Specification

Since the antioxidant and the light stabilizer specifically described or used in Patent Documents 1 and 2 are not evaporated or decomposed by heating at the time of film formation of the composition in the production of an organic EL device, these oxidation agents are used. When the inhibitor and the light stabilizer remain in the film after film formation, there is a problem that the performance of the organic EL element such as external quantum efficiency is lowered, and an improvement thereof has been demanded.

An object of the present invention is to solve the above problems and achieve the following object.
That is, the present invention uses an antioxidant that can be evaporated or decomposed by heating, and the antioxidant is evaporated or decomposed by heating at the time of film formation of the composition in the production of an organic electroluminescent device. In addition to the effect of improving the storage stability of the composition by using the antioxidant itself, durability, external quantum efficiency, etc., because the antioxidant does not substantially remain in the film after film formation It aims at providing the composition for organic electroluminescent elements which show | plays the effect of preventing the fall of organic EL element performance of this. Moreover, when the composition for organic electroluminescent elements of this invention is a coating liquid for light emitting layer formation, there exists an effect of preventing the fall of PL (photoluminescence) quantum yield in addition to said effect. It is an object to provide a composition for a light emitting device.
Another object of the present invention is to select and use an antioxidant (specifically, a liquid antioxidant) having a shape suitable as an antioxidant, so that a composition for an organic electroluminescent element (coating liquid) is used. And a composition for an organic electroluminescence device capable of preventing clogging due to precipitation of an antioxidant.
Still another object of the present invention is to provide a film, a light emitting layer, a charge transport layer, an organic electroluminescent device, a method for forming a light emitting layer, and a method for forming a charge transport layer using the above composition.

In view of the above situation, the present inventors have conducted extensive research and have used an antioxidant capable of evaporating or decomposing by heating, and heating when forming the composition in the production of an organic electroluminescent device. Thus, it has been found that the above-mentioned problems can be solved by the fact that the antioxidant is evaporated or decomposed and the antioxidant does not substantially remain in the film after film formation.

That is, the means for solving the above-mentioned problems are as follows.

[1] A composition for an organic electroluminescent device, wherein an antioxidant (A) that can be evaporated or decomposed by heating is added to a liquid containing an organic material (B) and a solvent (C), A composition for an organic electroluminescence device, wherein the antioxidant (A) evaporates or decomposes by heating when forming the film of the composition in the production of an organic electroluminescence device.
[2] The composition for organic electroluminescent elements as described in [1] above, wherein the antioxidant (A) is evaporated or decomposed by heating at 80 ° C. to 220 ° C.
[3] The composition for organic electroluminescent elements according to the above [1] or [2], wherein the antioxidant (A) is liquid at 25 ° C.
[4] The composition for organic electroluminescent elements according to any one of [1] to [3] above, wherein the antioxidant (A) is an alkylene glycol derivative, an amino alcohol derivative or oxalic acid.
[5] The composition for an organic electroluminescent element according to any one of [1] to [4], wherein the organic material (B) contains a light emitting material and a host material.
[6] The composition for an organic electroluminescent element according to the above [5], wherein the light emitting material is an iridium complex and the host material is a carbazole derivative.
[7] The composition for an organic electroluminescent element according to any one of [1] to [4], wherein the organic material (B) contains a charge transport material.
[8] The solvent (C) contains at least one selected from the group consisting of 2-butanone, butyl lactate, amyl lactate, isoamyl lactate and 2-n-butoxyethanol, [5] or [6] The composition for organic electroluminescent elements as described in 2.
[9] The composition for organic electroluminescent elements according to [7] above, containing cyclohexanone as the solvent (C).
[10] A film formed by applying the composition according to any one of [1] to [9] and heating the applied composition.
[11] A light emitting layer formed by applying the composition according to any one of [5], [6] and [8] and heating the applied composition.
[12] A charge transport layer formed by applying the composition according to [7] or [9] and heating the applied composition.
[13] An organic electroluminescence device having the light emitting layer according to [11].
[14] An organic electroluminescent device having the charge transport layer according to [12].
[15] A method for forming a light emitting layer, which comprises applying the composition according to any one of [5], [6] and [8], and heating the applied composition.
[16] A method for forming a charge transport layer, comprising applying the composition according to [7] or [9] above and heating the applied composition.

According to the present invention, an antioxidant that can be evaporated or decomposed by heating is used, and the antioxidant is evaporated or decomposed by heating at the time of film formation of the composition in the production of an organic electroluminescent element. In addition, since the antioxidant does not substantially remain in the film after film formation, the storage stability of the composition is improved by using the antioxidant itself (and the coating liquid for forming the light emitting layer). To provide a composition for an organic electroluminescent device that has the effect of preventing deterioration of organic EL device performance such as durability and external quantum efficiency in addition to the effect of preventing reduction of PL quantum yield. Can do.
In addition, according to the present invention, an organic electroluminescent element composition (coating liquid) can be obtained by selecting and using an antioxidant having a shape suitable as an antioxidant (specifically, a liquid antioxidant). Thus, it is possible to provide a composition for an organic electroluminescent device that can be easily mixed into the organic electroluminescent device and can be prevented from being clogged due to precipitation of an antioxidant.
Furthermore, according to the present invention, it is possible to provide a film, a light emitting layer, a charge transport layer, an organic electroluminescent element, a light emitting layer forming method and a charge transport layer forming method using the above composition.

It is the schematic which shows an example of the layer structure of the organic electroluminescent element which concerns on this invention.

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

In the present invention, the substituent group A and the substituent group B are defined as follows.
(Substituent group A)
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), alkenyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl , 3-pentynyl, etc.), aryl groups (preferably having 6 to 30 carbon atoms, more preferably carbon 6 to 20, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, anthracenyl, etc.), amino group (preferably 0 to 30 carbon atoms, more preferably 0 carbon atoms) To 20 and particularly preferably 0 to 10 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, ditolylamino, etc.), alkoxy groups (preferably having 1 to 30 carbon atoms). More preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), an aryloxy group (preferably 6 to 6 carbon atoms). 30, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, And aryloxy, 1-naphthyloxy, 2-naphthyloxy, etc.), heterocyclic oxy groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), an acyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 12 carbon atoms). , Benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms such as methoxycarbonyl, ethoxy Carbonyl, etc.), an aryloxycarbonyl group (preferably Has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonyl. ), An acyloxy group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetoxy, benzoyloxy, etc.), an acylamino group (preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, particularly preferably 2-10 carbon atoms, and examples thereof include acetylamino, benzoylamino and the like, and alkoxycarbonylamino groups (preferably having 2-2 carbon atoms). 30, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino, etc.), an aryloxycarbonylamino group (preferably having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, for example phenyloxycarbonyl And sulfonylamino groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino and benzenesulfonylamino). ), A sulfamoyl group (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenyl Sulfamoyl, etc.), carbamoyl groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, Phenylcarbamoyl etc.), alkylthio group ( Preferably, it has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, ethylthio, etc.), an arylthio group (preferably 6 to 30 carbon atoms). More preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, etc.), a heterocyclic thio group (preferably 1 to 30 carbon atoms, more preferably 1 to carbon atoms). 20, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio, etc.), a sulfonyl group (preferably having 1 carbon atom) To 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms such as mesyl and tosyl). A sulfinyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfinyl and benzenesulfinyl. ), A ureido group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid An amide group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenyl phosphoric acid amide), a hydroxy group , Mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group ( An aromatic heterocyclic group is also included, preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms. Is, for example, a nitrogen atom, oxygen atom, sulfur atom, phosphorus atom, silicon atom, selenium atom, tellurium atom, specifically pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl, pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, And isoxazolyl, isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl, piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl group, azepinyl group, silolyl group and the like. A silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyl and triphenylsilyl). A aryloxy group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, such as trimethylsilyloxy, triphenylsilyloxy, etc.), phosphoryl group (for example, A diphenylphosphoryl group, a dimethylphosphoryl group, etc.). These substituents may be further substituted, and examples of the further substituent include a group selected from the substituent group A described above. Moreover, the substituent substituted by the substituent may be further substituted, and examples of the further substituent include a group selected from the substituent group A described above. Moreover, the substituent substituted by the substituent substituted by the substituent may be further substituted, and examples of the further substituent include a group selected from the substituent group A described above.

(Substituent group B)
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), alkenyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl , 3-pentynyl, etc.), aryl groups (preferably having 6 to 30 carbon atoms, more preferably carbon 6 to 20, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, anthracenyl, etc.), cyano group, heterocyclic group (including aromatic heterocyclic group, Has 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, a silicon atom, a selenium atom, and a tellurium atom. Is pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl, pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl, piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolid Le, benzoimida Ryl, benzothiazolyl, carbazolyl group, azepinyl group, silylyl group, etc.) These substituents may be further substituted, and examples of further substituents include groups selected from the substituent group B. Can do. Moreover, the substituent substituted by the substituent may be further substituted, and examples of the further substituent include a group selected from the substituent group B described above. Moreover, the substituent substituted by the substituent substituted by the substituent may be further substituted, and examples of the further substituent include a group selected from the substituent group B described above.

The composition for organic electroluminescent elements of the present invention (hereinafter also simply referred to as “composition”) is an organic material obtained by adding an antioxidant that can be evaporated or decomposed by heating to a liquid containing an organic material and a solvent. In the composition for an electroluminescent element, the antioxidant is evaporated or decomposed by heating when the composition is formed in the production of the organic electroluminescent element.
The use of the composition of the present invention has the effect of improving the storage stability of the composition (and preventing the decrease in PL quantum yield in the case of a coating solution for forming a light emitting layer), as well as durability and external quantum. The reason why the effect of preventing the degradation of the organic EL element performance such as the efficiency can be obtained is not clear, but is estimated as follows.
The composition of the present invention contains an antioxidant, so that an organic material (specifically, a light emitting material and a host material described later) accompanying heating and drying when forming the film of the composition in the production of an organic electroluminescent element is used. Oxidation of the charge transport layer material, etc.). Further, when the composition of the present invention is a coating solution for forming a light emitting layer, it is possible to suppress decomposition of the light emitting material such as a phosphorescent light emitting material and the like accompanying heating, and prevent a decrease in PL quantum yield. be able to. In particular, this effect is remarkable when the phosphorescent material is an iridium complex having acetylacetonate (acac), which will be described later, as a ligand.
Further, the antioxidant according to the present invention is evaporated or decomposed by heating at the time of film formation of the composition in the production of an organic electroluminescence device, so that the antioxidant is substantially contained in the film after film formation. No longer remains. Antioxidants are insulators or compounds with extremely low mobility, and adversely affect carrier mobility, so that they remain in the film to reduce the organic EL device performance such as external quantum efficiency. It is presumed that the organic EL element performance such as external quantum efficiency can be prevented from deteriorating because it does not substantially remain in the film after film formation.

Here, “substantially does not remain in the film” means that the antioxidant does not substantially remain in the film due to evaporation or the antioxidant decomposes to have the original structure. It means that the antioxidant does not substantially remain in the film. Specifically, in the film after film formation, the antioxidant (which has the same structure as that contained in the composition) is based on the total solid content in the film after film formation, It is a state in which only 1000 ppm or less remains, preferably the remaining amount is 100 ppm or less, more preferably the remaining amount is 10 ppm or less, and most preferably 0 ppm (that is, no antioxidant remains in the film). .

The composition according to the present invention is preferably a composition for an organic electroluminescent device, more preferably a composition for forming a light emitting layer or a charge transport layer, and further preferably a light emitting layer, a hole injection layer or a hole transport. It is a composition for layer formation. Hereinafter, the structure of this composition is demonstrated.

[1] Antioxidant (A) that can be evaporated or decomposed by heating
The composition of the present invention contains an antioxidant that can be evaporated or decomposed by heating (hereinafter also referred to as “antioxidant (A)”). The antioxidant (A) evaporates or decomposes by heating when forming the composition of the present invention in the production of an organic electroluminescent device, and a known antioxidant satisfying this condition can be used. is there. Note that the heating temperature in forming the composition in the production of the organic electroluminescent device is generally within a temperature range that does not adversely affect the performance of the organic electroluminescent device, specifically 25 ° C. to 220 ° C. It is preferably 80 ° C. to 220 ° C., more preferably 150 ° C. to 220 ° C.

The antioxidant (A) evaporates or decomposes at the heating temperature when the composition is formed in the production of the organic electroluminescence device as described above. The antioxidant (A) is preferably evaporated or decomposed by heating at 80 ° C. to 220 ° C. under atmospheric pressure, more preferably 150 ° C. to 220 ° C., and further preferably 180 ° C. to 220 ° C.

As the antioxidant (A), it is preferable to use an antioxidant that is liquid at 25 ° C. (room temperature). By using a liquid antioxidant, mixing with the organic electroluminescent element composition (coating liquid) is facilitated, and clogging due to precipitation of the antioxidant can be prevented.
As the liquid antioxidant, the viscosity at 25 ° C. (room temperature) is preferably 0.5 to 30 mPa · s, more preferably 1 to 25 mPa · s from the viewpoint of liquid feeding property. More preferably, it is ˜20 mPa · s. The viscosity can be measured with a B-type rotational viscometer.

The antioxidant (A) is [1-1] an antioxidant that can be evaporated by heating (hereinafter also referred to as “antioxidant (A-1)”), or [1-2] heating. It is an antioxidant that can be decomposed by (hereinafter, also referred to as “antioxidant (A-2)”). Each will be described below. Commercially available antioxidants are described in the antioxidant handbook (published by Taiseisha).

[1-1] Antioxidant capable of being evaporated by heating (A-1)
The antioxidant (A-1) is liquid at 25 ° C. (room temperature). The preferred viscosity range of the antioxidant (A-1) is the same as the preferred viscosity range when the above-mentioned antioxidant (A) is in a liquid state. The antioxidant (A-1) is preferably evaporated by heating at 80 ° C. to 220 ° C. under atmospheric pressure, more preferably 150 ° C. to 220 ° C., and further preferably 180 ° C. to 220 ° C. .

Examples of the antioxidant (A-1) include alkylene glycol derivatives such as ethylene glycol derivatives and propylene glycol derivatives, amino alcohol derivatives and the like, preferably alkylene glycol derivatives, more preferably ethylene glycol derivatives.
The ethylene glycol derivative is a compound having a partial structure represented by — (CH ₂ ) ₂ O—, and is preferably represented by the following general formula (EG).

In the above general formula (EG),
R _EG and R _EG ′ each independently represents an alkyl group.
n _EG represents an integer of 1 or more.

The alkyl group represented by R _EG and R _EG ′ is a linear or branched alkyl group, and is preferably a linear chain. The alkyl group represented by R _EG and R _EG ′ preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and most preferably a methyl group.

n _EG is an integer of 1 or more. From the viewpoint of boiling point, n _EG is preferably an integer of 1 to 3.

Examples of the ethylene glycol derivative represented by the above general formula (EG) as the antioxidant (A-1) include 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, triethylene glycol dimethyl ether, diethylene glycol diester. Examples thereof include butyl ether, diethylene glycol butyl methyl ether, diethylene glycol ethyl methyl ether, and the like, preferably 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, diethylene glycol butyl methyl ether, and diethylene glycol ethyl methyl ether.

Examples of the propylene glycol derivative include propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and tripropylene glycol dimethyl ether. Preferred are propylene glycol dimethyl ether and dipropylene glycol dimethyl ether.

Examples of amino alcohol derivatives include triethanolamine, diethylethanolamine dibutylethanolamine, N-methyldiethanolamine, and the like, preferably triethanolamine and diethylethanolamine.

[1-2] Antioxidant capable of being decomposed by heating (A-2)
Antioxidant (A-2) is an antioxidant in which decomposition products generated by heating do not adversely affect the organic electroluminescence device. When the antioxidant is decomposed, it is volatilized as a low molecular weight compound. Therefore, the decomposition product of the antioxidant does not adversely affect the device. The antioxidant (A-2) may be liquid at 25 ° C. (room temperature) or solid. A preferable viscosity range when the antioxidant (A-2) is in a liquid state is the same as the preferable viscosity range when the above-mentioned antioxidant (A) is in a liquid state. The antioxidant (A-2) is preferably decomposed by heating at 80 ° C. to 220 ° C. under atmospheric pressure, more preferably 150 ° C. to 220 ° C., further preferably 180 ° C. to 220 ° C. .

An example of the antioxidant (A-2) is oxalic acid. Oxalic acid is a compound that acts with a weak reducing agent and can be decomposed at 189.5 ° C. Furthermore, although carbon monoxide, carbon dioxide, and low boiling point formic acid (boiling point 100.8 ° C.) are generated as decomposition products, they can be easily volatilized by heating. Moreover, there is no generation | occurrence | production of oxygen and water, and it is estimated that the influence on an organic electroluminescent element is small.

The antioxidant (A) is preferably the above-mentioned alkylene glycol derivative, amino alcohol derivative or oxalic acid.

When the antioxidant (A) is solid, the solubility parameter of the antioxidant (A) is preferably 7.0 to 13.0 in the composition of the present invention. According to this, since the antioxidant (A) has sufficient solubility in the solvent, it is compatible with the organic material and sufficiently dispersed, and phase separation does not occur even after film formation. And when an organic material contains a light emitting material, it can suppress that light emission nonuniformity arises because antioxidant (A) is fully disperse | distributed.

Here, when the organic material is a hole injection material or a hole transport material (a hole injection layer forming material or a hole transport layer forming material), the solubility parameter is 7.0 to 13.0. It is preferable to use the antioxidant (A) which is more preferably 8.5 to 13.0. On the other hand, when the organic material includes a light emitting material (light emitting layer forming material), it is preferable that the solubility parameter is 7.0 to 13.0, more preferably 7.5 to 10.5. It is desirable to use the agent (A).

When the antioxidant (A) is in a solid state, in the composition of the present invention, the solubility of the antioxidant (A) in the solvent described later is preferably 0.001% or more. According to this, since the antioxidant (A) has sufficient solubility in the solvent, it is compatible with the organic material and sufficiently dispersed, and phase separation does not occur even after film formation. And when an organic material contains a light emitting material, it can suppress that light emission nonuniformity arises because antioxidant (A) is fully disperse | distributed.

Here, when the organic material is a hole injection material or a hole transport material, it is desirable to use an antioxidant (A) having a solubility in a solvent of 0.001% or more, preferably 5% or more. Also, when the organic material includes a light emitting material, it is desirable to use an antioxidant (A) having a solubility in a solvent of 0.001% or more, preferably 5% or more.

In this invention, antioxidant (A) may be used independently and may be used in combination of 2 or more type.
The content of the antioxidant (A) in the composition is preferably 0.1 to 10% by mass based on the total solid content of the composition when the antioxidant (A) is in a solid state, More preferably, the content is 0.1 to 5% by mass, and still more preferably 0.2 to 3% by mass.
When the antioxidant (A) is a liquid, the concentration of the antioxidant (A) in the composition is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, and still more preferably 5%. ~ 20% by weight.
As the antioxidant (A) of the present invention, it is preferable to use a purified product. As the purification treatment, specifically, (1) column purification treatment of silica gel, alumina, cationic ion exchange resin, anionic ion exchange resin, etc., (2) anhydrous sodium sulfate, anhydrous calcium sulfate, magnesium sulfate, strontium sulfate, Dehydration treatment of barium sulfate, barium oxide, calcium oxide, magnesium oxide, molecular sieves, zeolite, etc. (3) Distillation treatment, (4) Bubbling treatment with inert gas (nitrogen, argon), etc. (5) Filtration, centrifugal sedimentation Arbitrary methods such as impurity removal treatment by (6) recrystallization and the like can be used. A purification method by column purification treatment, dehydration treatment, filtration, and recrystallization is more preferable.

[2] Organic material (B)
The composition of the present invention contains an organic material (hereinafter also referred to as “organic material (B)”). As an organic material (B), a well-known organic material can be used if it is an organic material which functions in an organic electroluminescent element.
As one embodiment of the present invention, the composition of the present invention preferably contains a light emitting material and a host material as the organic material (B). Thereby, the composition which can provide the element which has favorable storage stability and was excellent in PL quantum yield and external quantum efficiency is obtained. Note that, from the viewpoint of durability and efficiency of the EL element, it is more preferable that the light emitting material is an iridium (Ir) complex described later and the host material is a carbazole derivative described later.
As another embodiment of the present invention, the composition of the present invention preferably contains a charge transport material as the organic material (B). Thereby, a composition having good storage stability and capable of providing a device having excellent external quantum efficiency can be obtained.
Hereinafter, the light emitting material, the host material, and the charge transport material used as the organic material (B) will be described.

[2-1] Light-Emitting Material Examples of the light-emitting material used as the organic material (B) include a fluorescent light-emitting material and a phosphorescent light-emitting material. [0164], paragraph numbers [0088] to [0090] of JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

Examples of phosphorescent light-emitting materials that can be used in the present invention include US Pat. / 19373A2, JP-A No. 2001-247859, JP-A No. 2002-302671, JP-A No. 2002-117978, JP-A No. 2003-133074, JP-A No. 2002-1235076, JP-A No. 2003-123684, JP-A No. 2002-170684, EP No. 121157, JP-A No. 2002 -226495, JP 2002-234894, JP 2001-247859, JP 2001-298470, JP 2002-1736 4. JP 2002-203678, JP 2002-203679, JP 2004-357799, JP 2006-256999, JP 2007-19462, JP 2007-84635, JP 2007-96259, etc. Phosphorescent compounds and the like can be mentioned. Among them, more preferable light emitting materials include Ir complex, Pt complex, Cu complex, Re complex, W complex, Rh complex, Ru complex, Pd complex, Os complex, Eu complex, Tb complex, Examples thereof include phosphorescent metal complex compounds such as Gd complexes, Dy complexes, and Ce complexes. Particularly preferred is an Ir complex, a Pt complex, or a Re complex, among which an Ir complex or a Pt complex containing at least one coordination mode of a metal-carbon bond, a metal-nitrogen bond, a metal-oxygen bond, and a metal-sulfur bond. Or Re complexes are preferred. Furthermore, from the viewpoints of luminous efficiency, driving durability, chromaticity and the like, an Ir complex and a Pt complex are particularly preferable, and an Ir complex is most preferable.

As the phosphorescent material in the present invention, it is preferable to use an iridium complex represented by the following general formula (E-1) or a platinum complex represented by the following general formula (C-1).

The general formula (E-1) will be described.

In general formula (E-1), Z ¹ and Z ² each independently represent a carbon atom or a nitrogen atom.
A ₁ represents an atomic group that forms a 5- or 6-membered heterocycle with Z ¹ and a nitrogen atom.
B ₁ represents an atomic group that forms a 5- or 6-membered ring with Z ² and a carbon atom.
(XY) represents a monoanionic bidentate ligand.
n _E1 represents an integer of 1 to 3.

n _E1 represents an integer of 1 to 3, preferably 2 or 3.
Z ¹ and Z ² each independently represent a carbon atom or a nitrogen atom. Z ¹ and Z ² are preferably carbon atoms.

A ₁ represents an atomic group that forms a 5- or 6-membered heterocycle with Z ¹ and a nitrogen atom. The 5- or 6-membered heterocycle containing A ₁ , Z ¹ and a nitrogen atom includes a pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole Ring, thiadiazole ring and the like.
From the viewpoint of the stability of the complex, emission wavelength control, and emission quantum yield, the 5- or 6-membered heterocycle formed by A ₁ , Z ¹ and a nitrogen atom is preferably a pyridine ring, a pyrazine ring, an imidazole ring, or a pyrazole. A ring, more preferably a pyridine ring, an imidazole ring and a pyrazine ring, still more preferably a pyridine ring and an imidazole ring, and most preferably a pyridine ring.

The 5- or 6-membered heterocycle formed by the A ₁ , Z ¹ and the nitrogen atom may have a substituent, and as the substituent on the carbon atom, the substituent group A is on the nitrogen atom. The substituent group B can be applied as the substituent. Preferred substituents on carbon are alkyl groups, perfluoroalkyl groups, aryl groups, aromatic heterocyclic groups, dialkylamino groups, diarylamino groups, alkoxy groups, cyano groups, and fluorine atoms.

The substituent is appropriately selected for controlling the emission wavelength and potential, but in the case of shortening the wavelength, an electron donating group, a fluorine atom, and an aromatic ring group are preferable. For example, an alkyl group, a dialkylamino group, an alkoxy group, A fluorine atom, an aryl group, an aromatic heterocyclic group and the like are selected. In the case of increasing the wavelength, an electron withdrawing group is preferable, and for example, a cyano group, a perfluoroalkyl group, or the like is selected.

The substituent on nitrogen is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and an alkyl group or an aryl group is preferable from the viewpoint of the stability of the complex.
The substituents may be linked to form a condensed ring, and the formed ring includes a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, and a pyrazole. Ring, thiophene ring, furan ring and the like. These formed rings may have a substituent, and examples of the substituent include the substituent on the carbon atom and the substituent on the nitrogen atom.

B ₁ represents a 5- or 6-membered ring containing Z ² and a carbon atom. Examples of the 5- or 6-membered ring formed by B ₁ , Z ² and a carbon atom include a benzene ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazine ring, an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, Examples include a triazole ring, an oxadiazole ring, a thiadiazole ring, a thiophene ring, and a furan ring.
From the viewpoint of the stability of the complex, emission wavelength control and emission quantum yield, the benzene ring, pyridine ring, pyrazine ring, imidazole ring, pyrazole is preferable as the 5- or 6-membered ring formed by B ₁ , Z ² and carbon atom. A ring and a thiophene ring, more preferably a benzene ring, a pyridine ring and a pyrazole ring, and still more preferably a benzene ring and a pyridine ring.

The 5- or 6-membered ring formed of B ₁ , Z ² and a carbon atom may have a substituent, and the substituent group A is a substituent on a nitrogen atom as the substituent on the carbon atom. As the above, the substituent group B can be applied. Preferred substituents on carbon are alkyl groups, perfluoroalkyl groups, aryl groups, aromatic heterocyclic groups, dialkylamino groups, diarylamino groups, alkoxy groups, cyano groups, and fluorine atoms.

The substituent is appropriately selected for controlling the emission wavelength and potential, but in the case of increasing the wavelength, an electron donating group and an aromatic ring group are preferable, for example, an alkyl group, a dialkylamino group, an alkoxy group, an aryl group, An aromatic heterocyclic group or the like is selected. In order to shorten the wavelength, an electron withdrawing group is preferable, and for example, a fluorine atom, a cyano group, a perfluoroalkyl group, and the like are selected.

The substituent on nitrogen is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and an alkyl group or an aryl group is preferable from the viewpoint of the stability of the complex. The substituents may be linked to form a condensed ring, and the formed ring includes a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, and a pyrazole. Ring, thiophene ring, furan ring and the like. These formed rings may have a substituent, and examples of the substituent include the substituent on the carbon atom and the substituent on the nitrogen atom.
In addition, a 5- or 6-membered heterocyclic substituent formed by A ₁ , Z ¹ and a nitrogen atom and a 5- or 6-membered substituent formed by B ₁ , Z ² and a carbon atom are linked. Then, the same condensed ring as described above may be formed.

Examples of the ligand represented by (XY) include various known ligands used in conventionally known metal complexes. For example, “Photochemistry and Photophysics of Coordination Compounds” Springer-Verlag H. Published by Yersin in 1987, “Organometallic Chemistry-Fundamentals and Applications-” The ligands described in Akio Yamamoto's book published by Akio Yamamoto in 1982, etc. (for example, halogen ligands (preferably chlorine ligands), Nitrogen heteroaryl ligands (for example, bipyridyl, phenanthroline, etc.), diketone ligands (for example, acetylacetone, etc.) can be mentioned.
The ligands represented by (XY) are preferably the following general formulas (l-1) to (1-14), but the present invention is not limited to these.

* Represents the coordination position to iridium in the general formula (E-1). Rx, Ry and Rz each independently represents a hydrogen atom or a substituent.

When Rx, Ry, and Rz represent a substituent, examples of the substituent include a substituent selected from the substituent group A. Preferably, Rx and Rz are each independently an alkyl group, a perfluoroalkyl group, a fluorine atom or an aryl group, more preferably an alkyl group having 1 to 4 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, A fluorine atom and an optionally substituted phenyl group are most preferred, and a methyl group, an ethyl group, a trifluoromethyl group, a fluorine atom and a phenyl group are most preferred. Ry is preferably a hydrogen atom, an alkyl group, a perfluoroalkyl group, a fluorine atom or an aryl group, more preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an optionally substituted phenyl group. And most preferably a hydrogen atom or a methyl group. Since these ligands are considered not to be sites where charge is transported in the device or electrons are concentrated by excitation, Rx, Ry, and Rz may be chemically stable substituents. Will not be affected. Since complex synthesis is easy, (I-1), (I-4) and (I-5) are preferred, and (I-1) is most preferred. Complexes having these ligands can be synthesized in the same manner as in known synthesis examples by using corresponding ligand precursors. For example, in the same manner as described in International Publication No. 2009-073245, page 46, it can be synthesized by the following method using commercially available difluoroacetylacetone.
The ligand represented by (XY) is preferably a diketone or a picolinic acid derivative, and is acetylacetonate (acac) shown below from the viewpoint of obtaining stability of the complex and high luminous efficiency. Most preferred.

* Represents the coordination position to iridium.

A preferred embodiment of the Ir complex represented by the general formula (E-1) is an Ir complex represented by the general formula (E-2).

In general formula (E-2), A ^E1 to A ^E8 each independently represent a nitrogen atom or C—R ^E.
R ^E represents a hydrogen atom or a substituent.
(XY) represents a monoanionic bidentate ligand.
n _E2 represents an integer of 1 to 3.

A ^E1 to A ^E8 each independently represents a nitrogen atom or C—R ^E. R ^E represents a hydrogen atom or a substituent, and R ^E may be connected to each other to form a ring. Examples of the ring formed include the same ring as the condensed ring described in the general formula (E-1). Examples of the substituent represented by R ^E, we are the same as those mentioned above substituent group A.
Preferred as A ^E1 ~ ^{A E4} is ^{C-R ^E,} if A E1 ^{~ A E4} is ^{C-R ^E,} preferably a hydrogen atom ^{R E} of ^{A E3,} alkyl group, aryl group, amino group, An alkoxy group, an aryloxy group, a fluorine atom, or a cyano group, more preferably a hydrogen atom, an alkyl group, an amino group, an alkoxy group, an aryloxy group, or a fluorine atom, and particularly preferably a hydrogen atom or a fluorine atom. And R ^E of A ^E1 , A ^E2 and A ^E4 is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably a hydrogen atom, An alkyl group, an amino group, an alkoxy group, an aryloxy group, or a fluorine atom, particularly preferably a hydrogen atom.

A ^E5 to A ^E8 are preferably C—R ^E , and when A ^E5 to A ^E8 are C—R ^E , R ^E is preferably a hydrogen atom, alkyl group, perfluoroalkyl group, aryl group, aromatic A heterocyclic group, a dialkylamino group, a diarylamino group, an alkyloxy group, a cyano group, or a fluorine atom, more preferably a hydrogen atom, an alkyl group, a perfluoroalkyl group, an aryl group, a dialkylamino group, a cyano group, Or a fluorine atom, and more preferably a hydrogen atom, an alkyl group, a trifluoromethyl group, or a fluorine atom. If possible, the substituents may be linked to form a condensed ring structure. When the emission wavelength is shifted to the short wavelength side, A ^E6 is preferably a nitrogen atom.
(X-Y), and _{n E2} of the general formula in (E1) (X-Y) , and has the same meaning as _{n E1} preferable ranges are also the same.

A more preferred form of the compound represented by the general formula (E-2) is a compound represented by the following general formula (E-3).

In general formula (E-3), R ^T1 , R ^T2 , R ^T3 , R ^T4 , R ^T5 , R ^T6 and R ^T7 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, —CN, a perfluoroalkyl group, a trifluorovinyl group, —CO ₂ R, —C (O) R, —NR ₂ , —NO ₂ , —OR, a halogen atom, an aryl group or a heteroaryl group, and further a substituent Z may be included. Each R independently represents a hydrogen atom, an alkyl group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
A represents CR ′ or a nitrogen atom, and R ′ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, —CN, a perfluoroalkyl group, a trifluorovinyl group, —CO ₂ R, —C (O ) R, —NR ₂ , —NO ₂ , —OR, a halogen atom, an aryl group or a heteroaryl group, which may further have a substituent Z. Each R independently represents a hydrogen atom, an alkyl group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
R ^T1 to R ^T7 and R ′ may be bonded to each other to form a condensed 4- to 7-membered ring, and the condensed 4- to 7-membered ring is cycloalkyl, aryl or heteroaryl. The condensed 4- to 7-membered ring may further have a substituent Z. Among these, a case where a ring is condensed with R ^T1 and R ^T7 , or R ^T5 and R ^T6 to form a benzene ring is preferable, and a case where a ring is condensed with R ^T5 and R ^T6 to form a benzene ring is particularly preferable.
The substituents Z are each independently a halogen atom, —R ″, —OR ″, —N (R ″) ₂ , —SR ″, —C (O) R ″, —C (O) OR ″, —C ( O) represents N (R ″) ₂ , —CN, —NO ₂ , —SO ₂ , —SOR ″, —SO ₂ R ″, or —SO ₃ R ″, and each R ″ independently represents a hydrogen atom, alkyl Represents a group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
(XY) represents a monoanionic bidentate ligand. n _E3 represents an integer of 1 to 3.

The alkyl group may have a substituent, may be saturated or unsaturated, and examples of the group that may be substituted include the above-described substituent Z. The alkyl group represented by R ^T1 to R ^T7 and R ′ is preferably an alkyl group having 1 to 8 carbon atoms in total, more preferably an alkyl group having 1 to 6 carbon atoms in total, such as methyl Group, ethyl group, i-propyl group, cyclohexyl group, t-butyl group and the like.
The cycloalkyl group may have a substituent, may be saturated or unsaturated, and examples of the group that may be substituted include the above-described substituent Z. The cycloalkyl group represented by R ^T1 to R ^T7 and R ′ is preferably a cycloalkyl group having 4 to 7 ring members, more preferably a cycloalkyl group having 5 to 6 carbon atoms in total, A cyclopentyl group, a cyclohexyl group, etc. are mentioned.
The alkenyl group represented by R ^T1 to R ^T7 and R ′ preferably has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 10 carbon atoms. For example, vinyl, allyl, Examples include 1-propenyl, 1-isopropenyl, 1-butenyl, 2-butenyl, 3-pentenyl and the like.
The alkynyl group represented by R ^T1 to R ^T7 and R ′ preferably has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 10 carbon atoms. For example, ethynyl, propargyl , 1-propynyl, 3-pentynyl and the like.

Examples of the perfluoroalkyl group represented by R ^T1 to R ^T7 and R ′ include those in which all the hydrogen atoms of the aforementioned alkyl group are replaced with fluorine atoms.

The aryl group represented by R ^T1 to R ^T7 and R ′ is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, a tolyl group, or a naphthyl group.

The heteroaryl group represented by R ^T1 to R ^T7 and R ′ is preferably a heteroaryl group having 5 to 8 carbon atoms, more preferably a 5- or 6-membered substituted or unsubstituted heteroaryl group. Groups such as pyridyl, pyrazinyl, pyridazinyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, cinnolinyl, phthalazinyl, quinoxalinyl, pyrrolyl, indolyl, furyl, benzofuryl , Thienyl group, benzothienyl group, pyrazolyl group, imidazolyl group, benzimidazolyl group, triazolyl group, oxazolyl group, benzoxazolyl group, thiazolyl group, benzothiazolyl group, isothiazolyl group, benzisothiazolyl group, thiadiazolyl group, isoxazolyl group , Lens benzisoxazolyl group, a pyrrolidinyl group, a piperidinyl group, a piperazinyl group, an imidazolidinyl group, a thiazolinyl group, a sulfolanyl group, a carbazolyl group, a dibenzofuryl group, dibenzothienyl group, such as 7 pyrido-indolyl group. Preferred examples include pyridyl group, pyrimidinyl group, imidazolyl group, and thienyl group, and more preferred are pyridyl group and pyrimidinyl group.

R ^T1 to R ^T7 and R ′ are preferably a hydrogen atom, an alkyl group, a cyano group, a trifluoromethyl group, a perfluoroalkyl group, a dialkylamino group, a fluoro group, an aryl group or a heteroaryl group, more preferably A hydrogen atom, an alkyl group, a cyano group, a trifluoromethyl group, a fluoro group, and an aryl group are preferable, and a hydrogen atom, an alkyl group, and an aryl group are more preferable. As the substituent Z, an alkyl group, an alkoxy group, a fluoro group, a cyano group, and a dialkylamino group are preferable, and a hydrogen atom is more preferable.

Any two of R ^T1 to R ^T7 and R ′ may be bonded to each other to form a condensed 4- to 7-membered ring, and the condensed 4- to 7-membered ring is cycloalkyl, aryl, or heteroaryl; The condensed 4- to 7-membered ring may further have a substituent Z. The definition and preferred range of cycloalkyl, aryl, and heteroaryl formed are the same as the cycloalkyl group, aryl group, and heteroaryl group defined by R ^T1 to R ^T7 and R ′.
Further, it is particularly preferable that A represents CR ′, and among R ^T1 to R ^T7 and R ′, 0 to 2 are alkyl groups or phenyl groups, and the rest are all hydrogen atoms, and R ^T1 to R ^T7 , And R ′ are particularly preferably a case where 0 to 2 are alkyl groups and the rest are all hydrogen atoms.

n _E3 is preferably 2 or 3. The type of ligand in the complex is preferably composed of 1 to 2 types, more preferably 1 type. When introducing a reactive group into the complex molecule, it is also preferred that the ligand consists of two types from the viewpoint of ease of synthesis.
(XY) has the same meaning as (XY) in formula (E-1), and the preferred range is also the same.

One preferred form of the compound represented by the general formula (E-3) is a compound represented by the following general formula (E-4).

R ^T1 to R ^T4 , A, (XY) and n _E4 in the general formula (E-4) are R ^T1 to R ^T4 , A, (XY) and n _{E3 in the} general formula (E-3). The preferred range is also the same. R ₁ ′ to R ₅ ′ are each independently a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, alkynyl group, cyano group, perfluoroalkyl group, trifluorovinyl group, —CO ₂ R, —C (O) R , —NR ₂ , —NO ₂ , —OR, a halogen atom, an aryl group or a heteroaryl group, and optionally having a substituent Z. Each R independently represents a hydrogen atom, an alkyl group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
Any _{one of} R ₁ ′ to R ₅ ′ may be bonded to each other to form a condensed 4- to 7-membered ring, and the condensed 4- to 7-membered ring is cycloalkyl, aryl, or heteroaryl; The condensed 4- to 7-membered ring may further have a substituent Z.
Z is independently a halogen atom, —R ″, —OR ″, —N (R ″) ₂ , —SR ″, —C (O) R ″, —C (O) OR ″, —C (O) _{_{_{N (R ") 2, -CN}}} , -NO 2, -SO 2, -SOR", - SO 2 R ", or _-SO 3 R" represents, R "are each independently a hydrogen atom, an alkyl group, A perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group is represented.
Further, preferred ranges for R ₁ ′ to R ₅ ′ are the same as R ^T1 to R ^T7 and R ′ in formula (E-3). Particularly preferably, A represents CR ′, and 0 to 2 of R ^T1 to R ^T4 , R ′, and R ₁ ′ to R ₅ ′ are alkyl groups or phenyl groups, and the rest are all hydrogen atoms. , R ^T1 to R ^T4 , R ′, and R ₁ ′ to R ₅ ′ are more preferably a case where 0 to 2 are alkyl groups and the rest are all hydrogen atoms.

Another preferred embodiment of the compound represented by the general formula (E-3) is a compound represented by the following general formula (E-5).

R ^T2 to R ^T6 , A, (XY) and n _E5 in the general formula (E-5) are R ^T2 to R ^T6 , A, (XY) and n _{E3 in the} general formula (E-3). The preferred range is also the same. R ₆ ′ to R ₈ ′ are each independently a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, alkynyl group, cyano group, perfluoroalkyl group, trifluorovinyl group, —CO ₂ R, —C (O) R , —NR ₂ , —NO ₂ , —OR, a halogen atom, an aryl group or a heteroaryl group, and optionally having a substituent Z. Each R independently represents a hydrogen atom, an alkyl group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
R ^T5 , R ^T6 , R ₆ ′ to R ₈ ′ may be combined with each other to form a condensed 4- to 7-membered ring, and the condensed 4- to 7-membered ring is cycloalkyl, aryl or It is a heteroaryl, and the condensed 4- to 7-membered ring may further have a substituent Z.
Z is independently a halogen atom, —R ″, —OR ″, —N (R ″) ₂ , —SR ″, —C (O) R ″, —C (O) OR ″, —C (O) _{_{_{N (R ") 2, -CN}}} , -NO 2, -SO 2, -SOR", - SO 2 R ", or _-SO 3 R" represents, R "are each independently a hydrogen atom, an alkyl group, A perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group is represented.
In addition, preferred ranges for R ₆ ′ to R ₈ ′ are the same as R ^T1 to R ^T7 and R ′ in formula (E-3). Particularly preferably, A represents CR ′, and among R ^T2 to R ^T6 , R ′, and R ₆ ′ to R ₈ ′, 0 to 2 are alkyl groups or phenyl groups, and the rest are all hydrogen atoms. , R ^T2 to R ^T6 , R ′, and R ₆ ′ to R ₈ ′ are more preferably a case where 0 to 2 are alkyl groups and the rest are all hydrogen atoms.

Another preferred embodiment of the compound represented by the general formula (E-1) is a case represented by the following general formula (E-6).

In general formula (E-6), R _1a to R _1k each independently represent a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, alkynyl group, cyano group, perfluoroalkyl group, trifluorovinyl group, —CO ₂ R, —C (O) R, —NR ₂ , —NO ₂ , —OR, a halogen atom, an aryl group, or a heteroaryl group, which may further have a substituent Z. Each R independently represents a hydrogen atom, an alkyl group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
Any two of R _1a to R _1k may be bonded to each other to form a condensed 4- to 7-membered ring, and the condensed 4- to 7-membered ring is cycloalkyl, aryl, or heteroaryl; The 7-membered ring may further have a substituent Z.
Z is independently a halogen atom, —R ″, —OR ″, —N (R ″) ₂ , —SR ″, —C (O) R ″, —C (O) OR ″, —C (O) _{_{_{N (R ") 2, -CN}}} , -NO 2, -SO 2, -SOR", - SO 2 R ", or _-SO 3 R" represents, R "are each independently a hydrogen atom, an alkyl group, A perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group is represented.
(XY) represents a monoanionic bidentate ligand.
n _E6 represents an integer of 1 to 3.

In the general formula (E-6), preferred ranges of R _1a to R _1k are the same as those in R ^T1 to R ^T7 and R ′ in the general formula (E-3). Further, it is particularly preferred that 0 to 2 of R _1a to R _1k are alkyl groups or phenyl groups and the rest are all hydrogen atoms, and 0 to 2 of R _1a to R _1k are alkyl groups and the rest are all hydrogen atoms. More preferably, it is an atom.
The case where R _1j and R _1k are linked to form a single bond is particularly preferable.
The preferred range of (XY) and n _E6 is the same as (XY) and n _E3 in general formula (E-3).

A more preferable form of the compound represented by the general formula (E-6) is a case represented by the following general formula (E-7).

In general formula (E-7), R _1a to R _1i are each independently a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, alkynyl group, cyano group, perfluoroalkyl group, trifluorovinyl group, —CO ₂ R, —C (O) R, —NR ₂ , —NO ₂ , —OR, a halogen atom, an aryl group, or a heteroaryl group, which may further have a substituent Z. Each R independently represents a hydrogen atom, an alkyl group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group.
Any one of R _1a to R _1i may be bonded to each other to form a condensed 4- to 7-membered ring, and the condensed 4- to 7-membered ring is a cycloalkyl group, an aryl group, or a heteroaryl group; The condensed 4- to 7-membered ring may further have a substituent Z.
Z is independently a halogen atom, —R ″, —OR ″, —N (R ″) ₂ , —SR ″, —C (O) R ″, —C (O) OR ″, —C (O) _{_{_{N (R ") 2, -CN}}} , -NO 2, -SO 2, -SOR", - SO 2 R ", or _-SO 3 R" represents, R "are each independently a hydrogen atom, an alkyl group, A perhaloalkyl group, an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group or a heteroaryl group is represented.
(XY) represents a monoanionic bidentate ligand.
n _E7 represents an integer of 1 to 3.

In the formula _(E-7), definition and preferable ranges of R 1a _{~ R 1i} are the same as _R 1a _{~ R 1i} in the formula (E-6). Further, it is particularly preferable that 0 to 2 of R _1a to R _1i are alkyl groups or aryl groups and the rest are all hydrogen atoms. The definitions and preferred ranges of (XY) and n _E7 are the same as (XY) and n _E3 in general formula (E-3).

Preferred specific examples of the compound represented by the general formula (E-1) are listed below, but are not limited thereto.

The compounds exemplified as the compound represented by the general formula (E-1) can be synthesized by the method described in JP2009-99783A, various methods described in US Pat. No. 7,279,232 and the like. After synthesis, it is preferable to purify by sublimation purification after purification by column chromatography, recrystallization or the like. By sublimation purification, not only can organic impurities be separated, but inorganic salts and residual solvents can be effectively removed.

In the present invention, the iridium complex as the organic material (B) may be used alone or in combination of two or more.
The content of the iridium complex as the organic material (B) in the composition is preferably 2 to 30% by mass, more preferably 5 to 20% by mass, and still more preferably 5%, based on the total solid content of the composition. To 15% by mass.

The platinum complex that can be used as the phosphorescent material is preferably a platinum complex represented by the following general formula (C-1).

(In the formula, Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. L ¹ , L ² and L ³ are each independently a single bond or a divalent linking group. Represents.)

The general formula (C-1) will be described. Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. At this time, the bond between Q ¹ , Q ² , Q ³ and Q ⁴ and Pt may be any of a covalent bond, an ionic bond, a coordinate bond, and the like. As an atom couple | bonded with Pt in Q < ¹ >, Q < ² >, Q < ³ > and Q < ⁴ >, a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, and a phosphorus atom are preferable, and in Q < ¹ >, Q < ² >, Q < ³ > and Q < ⁴ > Of the atoms bonded to Pt, at least one is preferably a carbon atom, more preferably two are carbon atoms, particularly preferably two are carbon atoms and two are nitrogen atoms.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt by a carbon atom may be an anionic ligand or a neutral ligand, and the anionic ligand is a vinyl ligand, Aromatic hydrocarbon ring ligand (eg benzene ligand, naphthalene ligand, anthracene ligand, phenanthrene ligand etc.), heterocyclic ligand (eg furan ligand, thiophene ligand, pyridine) Ligand, pyrazine ligand, pyrimidine ligand, pyridazine ligand, triazine ligand, thiazole ligand, oxazole ligand, pyrrole ligand, imidazole ligand, pyrazole ligand, triazole And a condensed ring containing them (for example, quinoline ligand, benzothiazole ligand, etc.). A carbene ligand is mentioned as a neutral ligand.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a nitrogen atom may be neutral ligands or anionic ligands, and as neutral ligands, nitrogen-containing aromatic hetero Ring ligand (pyridine ligand, pyrazine ligand, pyrimidine ligand, pyridazine ligand, triazine ligand, imidazole ligand, pyrazole ligand, triazole ligand, oxazole ligand, Examples include thiazole ligands and condensed rings containing them (for example, quinoline ligands, benzimidazole ligands), amine ligands, nitrile ligands, and imine ligands. Examples of anionic ligands include amino ligands, imino ligands, nitrogen-containing aromatic heterocyclic ligands (pyrrole ligands, imidazole ligands, triazole ligands, and condensed rings containing them) (For example, indole ligand, benzimidazole ligand, etc.)).
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with an oxygen atom may be neutral ligands or anionic ligands, and neutral ligands are ether ligands, Examples include ketone ligands, ester ligands, amide ligands, oxygen-containing heterocyclic ligands (furan ligands, oxazole ligands and condensed rings containing them (benzoxazole ligands, etc.)). It is done. Examples of the anionic ligand include an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, an acyloxy ligand, a silyloxy ligand, and the like.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a sulfur atom may be neutral ligands or anionic ligands, and neutral ligands include thioether ligands, Examples include thioketone ligands, thioester ligands, thioamide ligands, sulfur-containing heterocyclic ligands (thiophene ligands, thiazole ligands and condensed rings containing them (such as benzothiazole ligands)). It is done. Examples of the anionic ligand include an alkyl mercapto ligand, an aryl mercapto ligand, and a heteroaryl mercapto ligand.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a phosphorus atom may be neutral ligands or anionic ligands, and neutral ligands include phosphine ligands, Examples include phosphate ester ligands, phosphite ester ligands, and phosphorus-containing heterocyclic ligands (phosphinin ligands, etc.). Anionic ligands include phosphino ligands and phosphinyl ligands. And phosphoryl ligands.
The groups represented by Q ¹ , Q ² , Q ^3, and Q ⁴ may have a substituent, and those listed as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other (when Q ³ and Q ⁴ are connected, a Pt complex of a cyclic tetradentate ligand is formed).

The group represented by Q ¹ , Q ² , Q ³ and Q ⁴ is preferably an aromatic hydrocarbon ring ligand bonded to Pt with a carbon atom, and an aromatic heterocyclic ligand bonded to Pt with a carbon atom. A nitrogen-containing aromatic heterocyclic ligand bonded to Pt with a nitrogen atom, an acyloxy ligand, an alkyloxy ligand, an aryloxy ligand, a heteroaryloxy ligand, a silyloxy ligand, and more Preferably, an aromatic hydrocarbon ring ligand bonded to Pt by a carbon atom, an aromatic heterocyclic ligand bonded to Pt by a carbon atom, a nitrogen-containing aromatic heterocyclic ligand bonded to Pt by a nitrogen atom , An acyloxy ligand, an aryloxy ligand, more preferably an aromatic hydrocarbon ring ligand bonded to Pt with a carbon atom, an aromatic heterocyclic ligand bonded to Pt with a carbon atom, a nitrogen atom Containing Pt Containing aromatic heterocyclic ligand, an acyloxy ligand.

L ¹ , L ² and L ³ represent a single bond or a divalent linking group. Examples of the divalent linking group represented by L ¹ , L ² and L ³ include alkylene groups (methylene, ethylene, propylene, etc.), arylene groups (phenylene, naphthalenediyl), heteroarylene groups (pyridinediyl, thiophenediyl, etc.) ), Imino group (—NR _L —) (such as phenylimino group), oxy group (—O—), thio group (—S—), phosphinidene group (—PR _L —) (such as phenylphosphinidene group), silylene _{_{(-SiR L R L '-)}} ( dimethylsilylene group, a diphenylsilylene group), or the like combinations thereof. Here, R _L and R _L ′ each independently represents a hydrogen atom or a substituent, and preferably represents a hydrogen atom, an alkyl group, or an aryl group. These linking groups may further have a substituent.
From the viewpoint of the stability of the complex and the emission quantum yield, L ¹ , L ² and L ³ are preferably a single bond, an alkylene group, an arylene group, a heteroarylene group, an imino group, an oxy group, a thio group or a silylene group. More preferably a single bond, an alkylene group, an arylene group or an imino group, still more preferably a single bond, an alkylene group or an arylene group, still more preferably a single bond, a methylene group or a phenylene group, still more preferably. Single bond, disubstituted methylene group, more preferably single bond, dimethylmethylene group, diethylmethylene group, diisobutylmethylene group, dibenzylmethylene group, ethylmethylmethylene group, methylpropylmethylene group, isobutylmethylmethylene group, diphenyl Methylene group, methylphenylmethylene group, cyclohexanediyl group, A lopentanediyl group, a fluorenediyl group, and a fluoromethylmethylene group.
L ¹ is particularly preferably a dimethylmethylene group, a diphenylmethylene group, or a cyclohexanediyl group, and most preferably a dimethylmethylene group.
L ² and L ³ are most preferably a single bond.

Of the platinum complexes represented by the general formula (C-1), a platinum complex represented by the following general formula (C-2) is more preferable.

(In the formula, L ²¹ represents a single bond or a divalent linking group. A ²¹ and A ²² each independently represents a carbon atom or a nitrogen atom. Z ²¹ and Z ²² each independently represent a nitrogen-containing aromatic heterocyclic ring. Z ²³ and Z ²⁴ each independently represents a benzene ring or an aromatic heterocycle.

The general formula (C-2) will be described. L ²¹ has the same meaning as L ^{1 in} formula (C-1), and the preferred range is also the same.

A ²¹ and A ²² each independently represent a carbon atom or a nitrogen atom. Of A ^21, A ^22, Preferably, at least one is a carbon atom, it A ^21, A ²² are both carbon atoms are preferred from the standpoint of emission quantum yield stability aspects and complexes of the complex .

Z ²¹ and Z ²² each independently represent a nitrogen-containing aromatic heterocycle. Examples of the nitrogen-containing aromatic heterocycle represented by Z ²¹ and Z ²² include a pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, Examples include thiadiazole rings. From the viewpoint of the stability of the complex, emission wavelength control and emission quantum yield, the ring represented by Z ²¹ and Z ²² is preferably a pyridine ring, a pyrazine ring, an imidazole ring or a pyrazole ring, more preferably a pyridine ring. , An imidazole ring and a pyrazole ring, more preferably a pyridine ring and a pyrazole ring, and particularly preferably a pyridine ring.

The nitrogen-containing aromatic heterocycle represented by Z ²¹ and Z ²² may have a substituent, and the substituent group A is a substituent on a carbon atom, and the substituent on a nitrogen atom is The substituent group B can be applied. The substituent on the carbon atom is preferably an alkyl group, a perfluoroalkyl group, an aryl group, an aromatic heterocyclic group, a dialkylamino group, a diarylamino group, an alkoxy group, a cyano group, or a fluorine atom. The substituent is appropriately selected for controlling the emission wavelength and potential, but in the case of shortening the wavelength, an electron donating group, a fluorine atom, and an aromatic ring group are preferable. For example, an alkyl group, a dialkylamino group, an alkoxy group, A fluorine atom, an aryl group, an aromatic heterocyclic group and the like are selected. Further, when the wavelength is increased, an electron withdrawing group is preferable, and for example, a cyano group, a perfluoroalkyl group, and the like are selected. The substituent on the nitrogen atom is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and an alkyl group or an aryl group is preferable from the viewpoint of the stability of the complex. The substituents may be linked to form a condensed ring, and the formed ring includes a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, and a pyrazole. Ring, thiophene ring, furan ring and the like.

Z ²³ and Z ²⁴ each independently represent a benzene ring or an aromatic heterocycle. Examples of the nitrogen-containing aromatic heterocycle represented by Z ²³ and Z ²⁴ include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadi Examples include an azole ring, a thiadiazole ring, a thiophene ring, and a furan ring. From the viewpoint of stability of the complex, emission wavelength control and emission quantum yield, the ring represented by Z ²³ and Z ²⁴ is preferably a benzene ring, a pyridine ring, a pyrazine ring, an imidazole ring, a pyrazole ring, or a thiophene ring, More preferred are a benzene ring, a pyridine ring and a pyrazole ring, and still more preferred are a benzene ring and a pyridine ring.

The benzene ring and nitrogen-containing aromatic heterocycle represented by Z ²³ and Z ²⁴ may have a substituent. As the substituent on the carbon atom, the substituent group A is substituted on the nitrogen atom. The substituent group B can be applied as the group. Preferred substituents on carbon are alkyl groups, perfluoroalkyl groups, aryl groups, aromatic heterocyclic groups, dialkylamino groups, diarylamino groups, alkoxy groups, cyano groups, and fluorine atoms. The substituent is appropriately selected for controlling the emission wavelength and potential, but in the case of increasing the wavelength, an electron donating group and an aromatic ring group are preferable, for example, an alkyl group, a dialkylamino group, an alkoxy group, an aryl group, An aromatic heterocyclic group or the like is selected. For shortening the wavelength, an electron withdrawing group is preferable, and for example, a fluorine atom, a cyano group, a perfluoroalkyl group, and the like are selected. The substituent on the nitrogen atom is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and an alkyl group or an aryl group is preferable from the viewpoint of the stability of the complex. The substituents may be linked to form a condensed ring, and the formed ring includes a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, and a pyrazole. Ring, thiophene ring, furan ring and the like.

Of the platinum complexes represented by the general formula (C-2), one of the more preferred embodiments is a platinum complex represented by the following general formula (C-4).

(In the general formula (C-4), A ⁴⁰¹ to A ⁴¹⁴ each independently represents C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ⁴¹ represents a single bond or a divalent linking group. To express.)

The general formula (C-4) will be described.
A ⁴⁰¹ to A ⁴¹⁴ each independently represents C—R or a nitrogen atom. R represents a hydrogen atom or a substituent.
As the substituent represented by R, those exemplified as the substituent group A can be applied.
A ⁴⁰¹ to A ⁴⁰⁶ are preferably C—R, and Rs may be connected to each other to form a ring. When A ⁴⁰¹ to A ⁴⁰⁶ are C—R, R in A ⁴⁰² and A ⁴⁰⁵ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom, or a cyano group. More preferably a hydrogen atom, an amino group, an alkoxy group, an aryloxy group or a fluorine atom, and particularly preferably a hydrogen atom or a fluorine atom. R in A ⁴⁰¹ , A ⁴⁰³ , A ⁴⁰⁴ and A ⁴⁰⁶ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably a hydrogen atom or an amino group. Group, an alkoxy group, an aryloxy group and a fluorine atom, and particularly preferably a hydrogen atom.
L ⁴¹ has the same meaning as L ^{1 in} formula (C-1), and the preferred range is also the same.

As A ⁴⁰⁷ to A ⁴¹⁴ , in each of A ⁴⁰⁷ to A ⁴¹⁰ and A ⁴¹¹ to A ⁴¹⁴ , the number of N (nitrogen atoms) is preferably 0 to 2, and more preferably 0 to 1. When shifting the emission wavelength to the short wavelength side, either A ⁴⁰⁸ or A ⁴¹² is preferably a nitrogen atom, and both A ⁴⁰⁸ and A ⁴¹² are more preferably nitrogen atoms.
When A ⁴⁰⁷ to A ⁴¹⁴ represent C—R, R in A ⁴⁰⁸ and A ⁴¹² is preferably a hydrogen atom, an alkyl group, a perfluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom, A cyano group, more preferably a hydrogen atom, a perfluoroalkyl group, an alkyl group, an aryl group, a fluorine atom or a cyano group, and particularly preferably a hydrogen atom, a phenyl group, a perfluoroalkyl group or a cyano group. R in A ⁴⁰⁷ , A ⁴⁰⁹ , A ⁴¹¹ and A ⁴¹³ is preferably a hydrogen atom, an alkyl group, a perfluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably Of these, a hydrogen atom, a perfluoroalkyl group, a fluorine atom, and a cyano group are preferable, and a hydrogen atom, a phenyl group, and a fluorine atom are particularly preferable. R in A ⁴¹⁰ and A ⁴¹⁴ is preferably a hydrogen atom or a fluorine atom, and more preferably a hydrogen atom. When any of A ⁴⁰⁷ to A ⁴⁰⁹ and A ⁴¹¹ to A ⁴¹³ represents CR, Rs may be connected to each other to form a ring.

Of the platinum complexes represented by the general formula (C-2), one of the more preferred embodiments is a platinum complex represented by the following general formula (C-5).

(In the general formula (C-5), A ⁵⁰¹ to A ⁵¹² each independently represents C—R or a nitrogen atom, R represents a hydrogen atom or a substituent, and L ⁵¹ represents a single bond or a divalent linkage. Represents a group.)

The general formula (C-5) will be described. A ⁵⁰¹ to A ⁵⁰⁶ and L ⁵¹ have the same ^{meanings as} A ⁴⁰¹ to A ⁴⁰⁶ and L ⁴¹ in formula (C-4), and preferred ranges are also the same.

A ⁵⁰⁷ , A ⁵⁰⁸ and A ⁵⁰⁹ and A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² and each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ⁵⁰⁷ , A ⁵⁰⁸ and A ⁵⁰⁹ and A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² are ^CR , R is preferably a hydrogen atom, an alkyl group, a perfluoroalkyl group, an aryl group, an aromatic heterocyclic group, Dialkylamino group, diarylamino group, alkyloxy group, cyano group, fluorine atom, more preferably hydrogen atom, alkyl group, perfluoroalkyl group, aryl group, dialkylamino group, cyano group, fluorine atom, more preferably , Hydrogen atom, alkyl group, trifluoromethyl group, fluorine atom. Further, when possible, substituents may be linked to form a condensed ring structure. At least one of A ⁵⁰⁷ , A ⁵⁰⁸ and A ⁵⁰⁹ and A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² is preferably a nitrogen atom, and particularly preferably A ⁵¹⁰ or A ⁵⁰⁷ is a nitrogen atom.

Among the platinum complexes represented by the general formula (C-1), another more preferable embodiment is a platinum complex represented by the following general formula (C-6).

(In the formula, L ⁶¹ represents a single bond or a divalent linking group. A ⁶¹ independently represents a carbon atom or a nitrogen atom. Z ⁶¹ and Z ⁶² each independently represent a nitrogen-containing aromatic heterocyclic ring. Z ⁶³ independently represents a benzene ring or an aromatic heterocycle, and Y is an anionic acyclic ligand bonded to Pt.)

The general formula (C-6) will be described. L ⁶¹ has the same meaning as L ^{1 in} formula (C-1), and the preferred range is also the same.

A ⁶¹ represents a carbon atom or a nitrogen atom. In view of the stability of the complex and the light emission quantum yield of the complex, A ⁶¹ is preferably a carbon atom.

Z ⁶¹ and Z ⁶² are synonymous with Z ²¹ and Z ²² in the general formula (C-2), respectively, and preferred ranges thereof are also the same. Z ⁶³ has the same meaning as Z ²³ in formula (C-2), and the preferred range is also the same.

Y is an anionic acyclic ligand that binds to Pt. An acyclic ligand is one in which atoms bonded to Pt do not form a ring in the form of a ligand. As an atom couple | bonded with Pt in Y, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, a nitrogen atom and an oxygen atom are more preferable, and an oxygen atom is the most preferable.
A vinyl ligand is mentioned as Y couple | bonded with Pt by a carbon atom. Examples of Y bonded to Pt with a nitrogen atom include an amino ligand and an imino ligand. Examples of Y bonded to Pt with an oxygen atom include an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, an acyloxy ligand, a silyloxy ligand, a carboxyl ligand, a phosphate ligand, Examples thereof include sulfonic acid ligands. Examples of Y bonded to Pt with a sulfur atom include alkyl mercapto ligands, aryl mercapto ligands, heteroaryl mercapto ligands, and thiocarboxylic acid ligands.
The ligand represented by Y may have a substituent, and those listed as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other.

The ligand represented by Y is preferably a ligand bonded to Pt with an oxygen atom, more preferably an acyloxy ligand, an alkyloxy ligand, an aryloxy ligand, a heteroaryloxy ligand. , A silyloxy ligand, and more preferably an acyloxy ligand.

Of the platinum complexes represented by the general formula (C-6), one of more preferred embodiments is a platinum complex represented by the following general formula (C-7).

(Wherein A ⁷⁰¹ to A ⁷¹⁰ each independently represents C—R or a nitrogen atom, R represents a hydrogen atom or a substituent, L ⁷¹ represents a single bond or a divalent linking group, Y represents An anionic acyclic ligand that binds to Pt.)

The general formula (C-7) will be described. L ⁷¹ has the same meaning as L ^{61 in} formula (C-6), and the preferred range is also the same. A ⁷⁰¹ to A ⁷¹⁰ have the same ^{meanings as} A ⁴⁰¹ to A ⁴¹⁰ in formula (C-4), and preferred ranges are also the same. Y has the same meaning as Y in formula (C-6), and the preferred range is also the same.

Specific examples of the platinum complex represented by the general formula (C-1) include [0143] to [0152], [0157] to [0158], and [0162] to [0168] of JP-A-2005-310733. The compounds described in JP-A-2006-256999, [0065] to [0083], the compounds described in JP-A-2006-93542, [0065] to [0090], JP-A-2007-73891 Nos. [0063] to [0071] in Japanese Patent Publication No. JP-A-2007-324309, Nos. [0079] to [0083] in Japanese Unexamined Patent Publication No. 2007-324309, No. [0065] to [0090] in Japanese Unexamined Patent Publication No. 2006-93542 Compounds described in JP-A-2007-96255, compounds described in [0055] to [0071], JP-A-2006-313796 [0043] include - [0046], platinum complexes exemplified other following can be mentioned.

Examples of the platinum complex compound represented by the general formula (C-1) include Journal of Organic Chemistry 53,786, (1988), G.S. R. Newkome et al. ), Page 789, method described in left column 53 to right column 7, line 790, method described in left column 18 to 38, method 790, method described in right column 19 to 30 and The combination, Chemische Berichte 113, 2749 (1980), H.C. Lexy et al.), Page 2752, lines 26 to 35, and the like.
For example, a ligand or a dissociated product thereof and a metal compound are mixed with a solvent (for example, a halogen solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfone solvent, In the presence of a sulfoxide solvent, water, etc., or in the absence of a solvent, in the presence of a base (inorganic and organic bases such as sodium methoxide, t-butoxypotassium, triethylamine, potassium carbonate, etc.) Or in the absence of a base, at room temperature or below, or by heating (in addition to normal heating, a method of heating with a microwave is also effective).

In this invention, the platinum complex as an organic material (B) may be used independently, and may be used in combination of 2 or more type.
The content of the platinum complex as the organic material (B) in the composition is preferably 2 to 50% by mass, more preferably 5 to 40% by mass, and still more preferably 10%, based on the total solid content of the composition. ~ 40% by weight.

[2-2] Host material A host material is a compound that causes energy transfer from its excited state to a light-emitting material, and as a result, causes the light-emitting material to emit light. Specific examples include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives. , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide oxide Derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, heterocycles such as naphthalene and perylene Carboxylic anhydride, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, metal complexes having benzoxazole, benzothiazole, etc. as ligands, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers , Conductive polymers such as thiophene oligomers and polythiophenes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, and the like. A host compound may be used individually by 1 type, or may use 2 or more types together.
Among these, from the viewpoint of durability, the host material is preferably a carbazole derivative or an imidazole derivative, and more preferably a carbazole derivative.

[Carbazole derivative]
The carbazole derivative is preferably a carbazole derivative represented by the following general formula (V).

(In the general formula (V), R ⁵¹ to R ⁵⁸ are a hydrogen atom, a deuterium atom, or a substituent, and R ⁵¹ to R ⁵⁸ may form a condensed ring between adjacent substituents. Represents a linking group, and n ⁵¹ represents an integer of 2 to 6.)

The substituents represented by R ⁵¹ to R ⁵⁸ are not particularly limited, and examples thereof include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, amino groups, alkoxy groups, aryloxy groups, and heterocyclic oxy groups. , Acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, heterocyclic thio group Sulfonyl group, sulfinyl group, ureido group, phosphoric acid amide group, hydroxy group, mercapto group, halogen atom, cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, hetero Group, a silyl group, such as silyloxy group. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

R ⁵¹ to R ⁵⁸ are preferably a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, a heteroaryl group, a halogen group, a cyano group, or a silyl group, and more preferably a hydrogen atom, a deuterium atom, an alkyl group, a hetero group An aryl group, a halogen group, a cyano group, and a silyl group, particularly preferably a hydrogen atom, a deuterium atom, an alkyl group, a heteroaryl group, and a silyl group. R ⁵¹ to R ⁵⁸ may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The alkyl group for R ⁵¹ to R ⁵⁸ is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-octyl, cyclopropyl, cyclopentyl, cyclohexyl, 1-adamantyl, trifluoromethyl, More preferred are methyl, isopropyl, tert-butyl, n-octyl, cyclopentyl, cyclohexyl, 1-adamantyl and trifluoromethyl, and particularly preferred are tert-butyl, cyclohexyl, 1-adamantyl and trifluoromethyl. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The heteroaryl group of R ⁵¹ to R ⁵⁸ is preferably imidazolyl, pyrazolyl, pyridyl, quinolyl, isoquinolinyl, pyrrolyl, indolyl, furyl, thienyl, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl, more preferably imidazolyl. , Pyrazolyl, quinolyl, indolyl, furyl, thienyl, benzimidazolyl, carbazolyl and azepinyl, particularly preferably indolyl, furyl, thienyl, benzimidazolyl, carbazolyl and azepinyl. These substituents may be further substituted with other substituents, may form a condensed ring structure, or these substituents may be bonded to each other to form a ring.

The silyl group of R ⁵¹ to R ⁵⁸ is preferably trimethylsilyl, triethylsilyl, triisopropylsilyl, methyldiphenylsilyl, dimethyl-tert-butylsilyl, dimethylphenylsilyl, diphenyl-tert-butylsilyl, triphenylsilyl, more preferably trimethylsilyl. , Triisopropylsilyl, dimethyl-tert-butylsilyl, diphenyl-tert-butylsilyl, and triphenylsilyl, particularly preferably trimethylsilyl, dimethyl-tert-butylsilyl, and triphenylsilyl. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

n ⁵¹ is preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2.

The linking group represented by A is preferably alkylene, arylene, heteroarylene, or silylene, more preferably arylene or heteroarylene, and particularly preferably arylene. These linking groups include, for example, ^These may be further substituted with the substituents represented by R ⁵¹ to R ⁵⁸ described above.

Arylene is preferably phenylene, naphthylene, biphenylene or terphenylene, more preferably phenylene or biphenylene, and particularly preferably phenylene.

Preferable phenylene is 1,2,3,4,5,6-hexasubstituted phenylene, 1,2,4,5-tetrasubstituted phenylene, 1,3,5-trisubstituted phenylene, 1,2-disubstituted phenylene 1,3-disubstituted phenylene, 1,4-disubstituted phenylene, more preferably 1,2-disubstituted phenylene, 1,3-disubstituted phenylene, 1,4-disubstituted phenylene, Preferred are 1,3-disubstituted phenylene and 1,4-disubstituted phenylene.

The heteroarylene is preferably disubstituted pyridylene or disubstituted N-phenylcarbazolylene, more preferably 2,6-disubstituted pyridylene, 3,5-disubstituted pyridylene, or 3,6-disubstituted N-phenyl. Carbazolylene, particularly preferably 3,6-disubstituted N-phenylcarbazolylene.
Examples of the compound having a carbazole group include the following compounds.

The carbazole derivative is preferably a carbazole derivative having an asymmetric structure represented by the following general formula (Acz).

In the general formula (ACz), R _As represents a tert-butyl group, a tert-amyl group, or a trimethylsilyl group.

In this invention, a host material may be used independently and may be used in combination of 2 or more type.
The content of the host material in the composition is preferably 50 to 95% by mass, more preferably 60 to 95% by mass, and still more preferably 70 to 95% by mass, based on the total solid content of the composition.

[2-3] Charge transport material Examples of the charge transport material include a hole injection material, a hole transport material, an electron injection material, an electron transport material, an exciton block material, a hole block material, and an electron block material.

Examples of the charge transport material include polyarylamine, polyfluorene, polythiophene, polyphenylene vinylene, polyvinyl carbazole, etc. Among these, from the viewpoint of device durability, polyarylamine, polyfluorene, polyvinyl carbazole are preferable, and polyarylamine Polyfluorene is more preferable.
Specific examples of the polyarylamine include PTPDES represented by the following structural formula (n is the number of repetitions of the structure in parentheses, and is an integer), PTPDES-2, PTTPDBA, PTPAES (Chemipro Kasei brand name) Etc.

As the charge transporting material, an arylamine derivative having at least one polymerizable group (hereinafter also referred to as “arylamine derivative (B)”) is preferable. As the arylamine derivative (B), a known compound can be used as long as it is an amine compound having an aryl group as a substituent and further having at least one polymerizable group. The polymerizable group possessed by the arylamine derivative (B) is not particularly limited, and examples thereof include a radical polymerizable group or a cationic polymerizable group. More specifically, cationically polymerizable groups such as epoxy group, oxetanyl group, oxazolyl group, vinyloxy group, alkenyl group, alkynyl group, acrylic ester (acryloyl group), methacrylic ester (methacryloyl group), acrylamide, methacryl Radical polymerizable groups such as amide, vinyl ether and vinyl ester are preferred. Of these, a radical polymerizable group is preferable and an alkenyl group or an alkynyl group is more preferable from the viewpoint that synthesis is easy and the polymerization reaction proceeds favorably.

In addition, as an alkenyl group, the group which has a double bond in the arbitrary positions of an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, and a silicon atom containing group is mentioned, for example. Of these, C 2-12 is preferable, and C 2-6 is more preferable. For example, a vinyl group, an allyl group, etc. are mentioned, and a vinyl group is preferable from the viewpoint of ease of polymerization control and mechanical strength.
Examples of the alkynyl group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, and a group having a triple bond at an arbitrary position of a silicon atom-containing group. Of these, C 2-12 is preferable, and C 2-6 is more preferable. From the viewpoint of ease of polymerization controllability, an ethynyl group is preferred.
Among these, from the viewpoint of reactivity, the polymerizable group of the arylamine derivative (B) is preferably either a vinyl group or an allyl group, and most preferably a vinyl group.
The arylamine derivative (B) preferably has at least two polymerizable groups from the viewpoint of film hardness and solvent resistance.

The arylamine derivative (B) is preferably a compound represented by the following general formula (1) or general formula (2) from the viewpoint of device durability.

(In the formula, R ₁ and R ₁ ′ each independently represent a polymerizable group. R ₂ and R ₂ ′ each independently represent a hydrogen atom or a substituent.)

(In the formula, R and R ′ each independently represents a polymerizable group.)

Specific examples and preferred ranges of the polymerizable group represented by R ₁ and R ₁ ′ in the general formula (1) and the polymerizable group represented by R and R ′ in the general formula (2) are as follows. The arylamine derivative (B) is the same as described for the polymerizable group.
The polymerizable group represented by R and R ′ is preferably substituted at the 3-position or 5-position of the benzene ring from the viewpoint of external quantum efficiency.
R ₂ and R ₂ ′ each independently represent a hydrogen atom or a substituent. Examples of the substituent represented by R ₂ and R ₂ ′ include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, a silicon atom-containing group having 1 to 12 carbon atoms, preferably carbon. It is an alkyl group of the number 1-5.
R ₂ and R ₂ ′ are preferably hydrogen atoms from the viewpoint of high mobility.

Next, specific examples of the arylamine derivative having a radical polymerizable group will be shown, but the present invention is not limited thereto.

In addition, it is preferable from the viewpoint of efficiency and durability that the composition according to the present invention is applied on a hole injection layer containing an iridium (Ir) complex to form a charge transport layer. The iridium (Ir) complex preferably has a polymerizable group from the viewpoint of efficiency. Examples of the polymerizable group include alkoxysilanes other than those described for the arylamine derivative (B). Specific examples of the Ir complex contained in the hole injection layer include the following Ir complexes, but the present invention is not limited to these.

The formation of the charge transport layer according to the present invention on a hole injection layer containing an Ir complex contributes to improvement in light emission efficiency and device durability.

In the present invention, the charge transport materials may be used alone or in combination of two or more.
The content of the charge transport material in the composition is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, and still more preferably 98 to 100% by mass, based on the total solid content of the composition.

[3] Solvent (C)
Examples of the solvent (hereinafter also referred to as “solvent (C)”) that can be used in preparing the composition by dissolving the above-described components include, for example, aromatic hydrocarbon solvents, alcohol solvents, and ketone solvents. Known organic solvents such as solvents, aliphatic hydrocarbon solvents, amide solvents, ester solvents and the like can be mentioned.

Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, cumeneethylbenzene, methylpropylbenzene, methylisopropylbenzene, and the like, and toluene, xylene, cumene, and trimethylbenzene are more preferable. .

Examples of alcohol solvents include methanol, ethanol, 2-n-butoxyethanol, butanol, benzyl alcohol, and cyclohexanol. 2-n-butoxyethanol, butanol, benzyl alcohol, and cyclohexanol are more preferable as ketone solvents. 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, 2-butanone, diisobutylketone, cyclohexanone, methylcyclohexanone, phenylacetone, methylisobutylketone , Acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, NMP (N-methylpyrrolidone) and the like, and 2-butanone, cyclohexanone, methyl isobutyl ketone, propylene carbonate, and NMP (N-methylpyrrolidone) are preferable.
Examples of the aliphatic hydrocarbon solvent include pentane, hexane, octane, decane and the like, and octane and decane are preferable.
Examples of amide solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 1,3-dimethyl-2-imidazolidinone and the like. N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferred.
Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl. Ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, amyl lactate And isoamyl lactate, and the like, and butyl lactate, amyl lactate, and isoamyl lactate are preferable.
In the present invention, the above solvents may be used alone or in combination of two or more.

When the composition of the present invention contains a light emitting material and a host material as the organic material (B), the solvent (C) is selected from the group consisting of the above-mentioned alcohol solvents, ketone solvents and ester solvents. It preferably contains at least one, and more preferably contains at least one selected from the group consisting of 2-butanone, butyl lactate, amyl lactate, isoamyl lactate and 2-n-butoxyethanol. By using these solvents (C) together with the antioxidant (A), even when a solvent that is originally not excellent in storage stability (for example, butyl lactate, isoamyl lactate, etc.) is used, Storage stability is improved.
In addition, when the composition of the present invention contains a charge transport material as the organic material (B), from the viewpoint of preventing deterioration of the organic EL device performance such as external quantum efficiency, the solvent (C) may be the above-mentioned ketone-based material. It preferably contains a solvent, more preferably contains cyclohexanone and NMP (N-methylpyrrolidone), and more preferably contains cyclohexanone. The effect of preventing a decrease in external quantum efficiency is effective at the time of drying when a high boiling point solvent such as cyclohexanone (bp = 155 ° C.), NMP (N-methylpyrrolidone) (bp = 202 ° C.) is used.
The solvent (C) of the present invention is preferably a purified product. As the purification treatment, specifically, (1) column purification treatment of silica gel, alumina, cationic ion exchange resin, anionic ion exchange resin, etc., (2) anhydrous sodium sulfate, anhydrous calcium sulfate, magnesium sulfate, strontium sulfate, Dehydration treatment of barium sulfate, barium oxide, calcium oxide, magnesium oxide, molecular sieves, zeolite, etc. (3) Distillation treatment, (4) Bubbling treatment with inert gas (nitrogen, argon), (5) Filtration, centrifugal sedimentation Arbitrary methods, such as the removal process of the impurity by etc., can be used. A purification method by column purification treatment, dehydration treatment, and filtration is more preferable.

[4] Formation of film The present invention also relates to a film formed by applying the composition of the present invention and heating the applied composition.
When the composition of the present invention contains a light emitting material and a host material as the organic material (B), the present invention is a light emitting layer formed by applying the composition and heating the applied composition. Also related. The present invention further relates to a method for forming a light emitting layer, which comprises applying the composition of the present invention and heating the applied composition.
When the composition of the present invention contains a charge transport material as the organic material (B), the present invention is a charge transport layer formed by applying the composition and heating the applied composition. Also related. The present invention further relates to a method for forming a charge transport layer, which comprises applying the composition of the present invention and heating the applied composition.

The light emitting layer is preferably used in a thickness of 10 to 200 nm, more preferably in a thickness of 20 to 80 nm. Such a film thickness can be obtained by setting the solid content concentration in the composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The charge transport layer is preferably used in a thickness of 5 to 50 nm, more preferably in a thickness of 5 to 40 nm. Such a film thickness can be obtained by setting the solid content concentration in the composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The charge transport layer is preferably a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an exciton block layer, a hole block layer, or an electron block layer, more preferably a hole injection layer. , A hole transport layer.
The total solid content in the composition of the present invention is generally 1 to 20% by mass, more preferably 1 to 10% by mass, and further preferably 2 to 10% by mass.
The viscosity of the composition of the present invention is generally 1 to 30 mPa · s, more preferably 1.5 to 20 mPa · s, and still more preferably 1.5 to 15 mPa · s.

The composition of the present invention is used by dissolving the above components in a predetermined organic solvent, filtering the solution, and then applying the solution on a predetermined support or layer as follows. The pore size of the filter used for filter filtration is 2.0 μm or less, more preferably 0.5 μm or less, and still more preferably 0.3 μm or less made of polytetrafluoroethylene, polyethylene, or nylon.

The coating method of the composition of the present invention is not particularly limited, and can be formed by any conventionally known coating method. Examples thereof include an ink jet method, a spray coating method, a spin coating method, a bar coating method, a transfer method, and a printing method.
The heating temperature after coating is generally 80 ° C to 220 ° C, more preferably 100 ° C to 200 ° C, still more preferably 100 ° C to 180 ° C. The heating time is generally 1 minute to 60 minutes, preferably 2 minutes to 30 minutes, more preferably 5 minutes to 30 minutes. Furthermore, a vacuum drying method may be used to promote drying of the high boiling point solvent.
The application and drying are preferably performed at a low oxygen concentration and a low dew point temperature. As oxygen concentration, 1000 ppm or less is preferable, More preferably, it is 100 ppm or less, More preferably, it is 10 ppm or less. The dew point temperature is preferably −40 ° C. or lower, more preferably −60 ° C. or lower, and further preferably −80 ° C. or lower. In addition, about application | coating and drying, it is preferable to carry out in the glove box which maintained the above-mentioned oxygen concentration and dew point temperature.

[5] Organic electroluminescent device The organic electroluminescent device of the present invention will be described in detail.
The organic electroluminescent element in the present invention has a light emitting layer or a charge transport layer formed from the composition of the present invention.
More specifically, the organic electroluminescent device according to the present invention is an organic electroluminescent device having a pair of electrodes including an anode and a cathode on a substrate, and at least one organic layer between the electrodes, It has the light emitting layer or charge transport layer formed from the composition of this invention as one organic layer.

The organic electroluminescent element of the present invention may further have an organic layer in addition to the light emitting layer or the charge transport layer.
In view of the properties of the light-emitting element, at least one of the anode and the cathode is preferably transparent or translucent.
FIG. 1 shows an example of the configuration of an organic electroluminescent device according to the present invention.
In the organic electroluminescent element 10 according to the present invention shown in FIG. 1, a light emitting layer 6 is sandwiched between an anode 3 and a cathode 9 on a support substrate 2. Specifically, a hole injection layer 4, a hole transport layer 5, a light emitting layer 6, a hole block layer 7, and an electron transport layer 8 are laminated in this order between the anode 3 and the cathode 9.

<Structure of organic layer>
There is no restriction | limiting in particular as a layer structure of the said organic layer, Although it can select suitably according to the use and objective of an organic electroluminescent element, It is formed on the said transparent electrode or the below-mentioned back electrode. preferable. In this case, the organic layer is formed on the front surface or one surface of the transparent electrode or the back electrode described later.
There is no restriction | limiting in particular about the shape of a organic layer, a magnitude | size, thickness, etc., According to the objective, it can select suitably.

Specific examples of the layer configuration include the following, but the present invention is not limited to these configurations.
Anode / hole transport layer / light-emitting layer / electron transport layer / cathode Anode / hole transport layer / light-emitting layer / block layer / electron transport layer / cathode Anode / hole transport layer / light-emitting layer / block layer / electron Transport layer / electron injection layer / cathode ・ Anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode ・ Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection Layer / Cathode ・ Anode / Hole injection layer / Hole transport layer / Light emitting layer / Block layer / Electron transport layer / Cathode ・ Anode / Hole injection layer / Hole transport layer / Light emitting layer / Block layer / Electron transport layer / Electron injection layer / cathode ・ Anode / hole injection layer / hole transport layer / exciton block layer / light emitting layer / electron transport layer / electron injection layer / cathode For device configuration of organic electroluminescent device, substrate, cathode and anode For example, it is described in detail in Japanese Patent Laid-Open No. 2008-270736, and matters described in the gazette It can be applied to the present invention.

<Board>
The substrate used in the present invention is preferably a substrate that does not scatter or attenuate light emitted from the organic layer. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.

<Anode>
The anode usually only needs to have a function as an electrode for supplying holes to the organic layer, and there is no particular limitation on the shape, structure, size, etc., depending on the use and purpose of the light-emitting element, It can select suitably from well-known electrode materials. As described above, the anode is usually provided as a transparent anode.

<Cathode>
The cathode usually has a function as an electrode for injecting electrons into the organic layer, and there is no particular limitation on the shape, structure, size, etc., and it is known depending on the use and purpose of the light-emitting element. The electrode material can be selected as appropriate.

Regarding the substrate, anode, and cathode, the matters described in paragraph numbers [0070] to [0089] of JP-A-2008-270736 can be applied to the present invention.

<Organic layer>
The organic layer in the present invention will be described.

[Formation of organic layer]
In the organic electroluminescent device of the present invention, each organic layer is formed by a solution coating process such as a dry film forming method such as an evaporation method or a sputtering method, a transfer method, a printing method, a spin coating method, a bar coating method, an ink jet method, or a spray method. Any of these can be suitably formed.

In addition to the light emitting layer or the charge transport layer formed from the composition of the present invention, any one of the organic layers is particularly preferably formed by a wet method. The other layers can be formed by appropriately selecting a dry method or a wet method. When the wet method is used, the organic layer can be easily increased in area, and a light-emitting element having high luminance and excellent light emission efficiency can be obtained efficiently at low cost, which is preferable. Vapor deposition, sputtering, etc. can be used as dry methods, and dipping, spin coating, dip coating, casting, die coating, roll coating, bar coating, gravure coating, and spray coating as wet methods. An ink jet method or the like can be used. These film forming methods can be appropriately selected according to the material of the organic layer. When the film is formed by a wet method, it may be dried after the film is formed. Drying is performed by selecting conditions such as temperature and pressure so that the coating layer is not damaged.

The coating solution used in the wet film-forming method (coating process) usually comprises an organic layer material and a solvent for dissolving or dispersing it. A solvent is not specifically limited, What is necessary is just to select according to the material used for an organic layer. Specific examples of solvents include halogen solvents (chloroform, carbon tetrachloride, dichloromethane, 1,2-dichloroethane, chlorobenzene, etc.), ketone solvents (acetone, diethyl ketone, n-propyl methyl ketone, 2-butanone, cyclohexanone, etc.) ), Aromatic solvents (benzene, toluene, xylene, etc.), ester solvents (ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, diethyl carbonate, etc.), ether Examples thereof include system solvents (tetrahydrofuran, dioxane, etc.), amide solvents (dimethylformamide, dimethylacetamide, etc.), dimethyl sulfoxide, alcohol solvents (methanol, propanol, butanol, etc.), water and the like.
The solid content with respect to the solvent in the coating solution is not particularly limited, and the viscosity of the coating solution can be arbitrarily selected according to the film forming method.

[Light emitting layer]
In the organic electroluminescent element of the present invention, the light emitting layer contains the above-described light emitting material, but may further contain a phosphorescent compound as another light emitting material. The phosphorescent compound is not particularly limited as long as it is a compound that can emit light from triplet excitons. As the phosphorescent compound, an orthometalated complex or a porphyrin complex is preferably used, and an orthometalated complex is more preferably used. Of the porphyrin complexes, a porphyrin platinum complex is preferred. The phosphorescent compounds may be used alone or in combination of two or more.

The ortho-metalated complex referred to in the present invention refers to Akio Yamamoto's “Organic Metal Chemistry Fundamentals and Applications”, pages 150 and 232, Hankabo (1982), H.C. Yersin's “Photochemistry and Photophysics of Coordination Compounds”, pages 71 to 77 and pages 135 to 146, Springer-Verlag (1987), etc. The ligand forming the orthometalated complex is not particularly limited, but a 2-phenylpyridine derivative, a 7,8-benzoquinoline derivative, a 2- (2-thienyl) pyridine derivative, a 2- (1-naphthyl) pyridine derivative or A 2-phenylquinoline derivative is preferred. These derivatives may have a substituent. Moreover, you may have another ligand other than these essential ligands for ortho metalation complex formation. As the central metal forming the orthometalated complex, any transition metal can be used. In the present invention, rhodium, platinum, gold, iridium, ruthenium, palladium and the like can be preferably used. Of these, iridium is particularly preferable. An organic layer containing such an orthometalated complex is excellent in light emission luminance and light emission efficiency. Specific examples of ortho-metalated complexes are also described in paragraphs 0152 to 0180 of Japanese Patent Application No. 2000-254171.

The orthometalated complex used in the present invention is Inorg. Chem. 30, 1685, 1991, Inorg. Chem. 27, 3464, 1988, Inorg. Chem. 33, 545, 1994, Inorg. Chim. Acta, 181, 245, 1991; Organomet. Chem. , 335, 293, 1987; Am. Chem. Soc. , 107, 1431, 1985 and the like.

The contents of the light-emitting material and the phosphorescent compound in the light-emitting layer are not particularly limited, but are, for example, 0.1 to 70% by mass, and preferably 1 to 20% by mass. If the content of the light emitting material and the phosphorescent compound is less than 0.1% by mass or exceeds 70% by mass, the effect may not be sufficiently exhibited.

In the present invention, the light emitting layer contains the above-mentioned host material, but may further contain a host compound as necessary.

The host compound is a compound that causes energy transfer from the excited state to the phosphorescent compound, and as a result, causes the phosphorescent compound to emit light. Specific examples include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives. , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide oxide Derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, heterocycles such as naphthalene and perylene Carboxylic anhydride, phthalocyanine derivative, metal complex of 8-quinolinol derivative, metal phthalocyanine, metal complex having benzoxazole or benzothiazole as a ligand, polysilane compound, poly (N-vinylcarbazole) derivative, aniline copolymer , Conductive polymers such as thiophene oligomers and polythiophenes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, and the like. A host compound may be used individually by 1 type, or may use 2 or more types together.

The thickness of the light emitting layer is preferably 10 to 200 nm, more preferably 20 to 80 nm. When the thickness exceeds 200 nm, the driving voltage may increase. When the thickness is less than 10 nm, the light emitting element may be short-circuited.

(Hole injection layer, hole transport layer)
The organic electroluminescent element of the present invention preferably has at least one of a hole injection layer and a hole transport layer. The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. The hole injection layer and the hole transport layer are preferably formed from the composition of the present invention each containing a hole injection material and a hole transport material as the organic material (B).
The hole injection layer and the hole transport layer are described in detail, for example, in JP-A-2008-270736 and JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

(Electron injection layer, electron transport layer)
The organic electroluminescent element of the present invention may have an electron injection layer and an electron transport layer. The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injection material and the electron transport material used for these layers may be a low molecular compound or a high molecular compound.
The electron injection layer and the electron transport layer are described in detail, for example, in JP-A-2008-270736 and JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

(Hole blocking layer)
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. In the present invention, a hole blocking layer can be provided as an organic layer adjacent to the light emitting layer on the cathode side.
Examples of organic compounds constituting the hole blocking layer include aluminum (III) bis (2-methyl-8-quinolinolato) 4-phenylphenolate (Aluminum (III) bis (2-methyl-8-quinolinato) 4- aluminum complexes such as phenylphenolate (abbreviated as BAlq), triazole derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10-) phenanthroline derivatives such as phenanthroline (abbreviated as BCP), triphenylene derivatives, carbazole derivatives, and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm.
The hole blocking layer may have a single layer structure made of one or more of the materials described above, or may have a multilayer structure made of a plurality of layers having the same composition or different compositions.

(Electronic block layer)
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side. In the present invention, an electron blocking layer can be provided as an organic layer adjacent to the light emitting layer on the anode side.
As an example of the organic compound constituting the electron blocking layer, for example, those mentioned as the hole transport material described above can be applied.
The thickness of the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm.
The electron blocking layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

(Description of exciton block layer)
The exciton blocking layer is a layer formed at one or both of the interface between the light emitting layer and the hole transport layer, or the interface between the light emitting layer and the electron transport layer, and the excitons generated in the light emitting layer are holes. It is a layer that diffuses into the transport layer and the electron transport layer and prevents deactivation without emitting light. The exciton blocking layer is preferably made of a carbazole derivative.

[Other organic layers]
The organic electroluminescence device of the present invention has a protective layer described in JP-A-7-85974, 7-192866, 8-22891, 10-275682, 10-106746, etc. Also good. The protective layer is formed on the uppermost surface of the light emitting element. Here, when the base material, the transparent electrode, the organic layer, and the back electrode are laminated in this order, the top surface refers to the outer surface of the back electrode, and the base material, the back electrode, the organic layer, and the transparent electrode are laminated in this order. In some cases, it refers to the outer surface of the transparent electrode. The shape, size, thickness and the like of the protective layer are not particularly limited. The material for forming the protective layer is not particularly limited as long as it has a function of suppressing intrusion or permeation of a light-emitting element such as moisture or oxygen into the element. Silicon, germanium oxide, germanium dioxide or the like can be used.

The method for forming the protective layer is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular sensing epitaxy, cluster ion beam, ion plating, plasma polymerization, plasma CVD, laser CVD Thermal CVD method, coating method, etc. can be applied.

[Sealing]
The organic electroluminescent element is preferably provided with a sealing layer for preventing moisture and oxygen from entering. As a material for forming the sealing layer, a copolymer of tetrafluoroethylene and at least one comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, polyethylene, polypropylene, polymethyl methacrylate, polyimide, Polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, chlorotrifluoroethylene or a copolymer of dichlorodifluoroethylene and another comonomer, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0. 1% or less moisture-proof material, metal (In, Sn, Pb, Au, Cu, Ag, Al, Tl, Ni, etc.), metal oxide (MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, _{_{_{CaO, BaO, Fe 2 O 3}}} , Y 2 O 3, TiO 2 , etc.), metal fluorides (M _{_{F 2, LiF, AlF 3,}} CaF 2 , etc.), liquid fluorinated carbon (perfluoroalkane, perfluoro amines, perfluoroether, etc.), the liquid fluorinated carbon as dispersed adsorbent moisture or oxygen, etc. Can be used.

The organic electroluminescence device of the present invention emits light by applying a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. Obtainable.

The driving method of the organic electroluminescence device of the present invention is described in JP-A-2-148687, JP-A-6-301355, JP-A-5-290080, JP-A-7-134558, JP-A-8-234585, and JP-A-8-2441047. The driving methods described in each publication, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429, 6023308, and the like can be applied.

Hereinafter, the present invention will be described more specifically with reference to examples. The materials, reagents, substance amounts and ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

[Addition of antioxidant to light-emitting layer coating solution]
<Measurement of PL quantum yield>
A quartz glass substrate having a thickness of 1.1 mm and a 25 mm square was alkali washed and rinsed, and then ultrasonically washed in 2-propanol, followed by UV-ozone treatment for 30 minutes. A single light emitting layer film was formed on this glass by the method described in Example 1-1 using the light emitting layer coating solutions prepared in Examples 1-1 and 2-1 and Comparative Example 1-1 below.
Using an absolute PL quantum yield measuring apparatus C9920-02 (manufactured by Hamamatsu Photonics Co., Ltd.), the PL quantum yield of the formed light emitting layer single film was measured. As a reference, quartz glass on which no film was formed was used.

Example 1-1
A mixed solvent A was prepared by dissolving 20 parts by mass of an antioxidant: 1,2-dimethoxyethane (boiling point 85 ° C.) in 80 parts by mass of 2-butanone for electronic industry. A light-emitting layer coating solution A was prepared by dissolving 98 parts by mass of a mixed solvent A, 1.8 parts by mass of a carbazole host having the following structural formula H-1 and 0.2 parts by mass of an Ir complex having the following structural formula E-1. .
Luminescence prepared by adding molecular sieve (trade name: Molecular sieve 3A 1/16, manufactured by Wako Pure Chemical Industries, Ltd.) to the light-emitting layer coating liquid A, and filtering using a syringe filter having a pore size of 0.22 μm in a glove box. The layer coating solution is spin-coated in a glove box (dew point -60 ° C., oxygen concentration 10 ppm), dried at 120 ° C. for 30 minutes and annealed at 160 ° C. for 10 minutes. Formed on a substrate.

Example 2-1
Antioxidant described in Example 1-1: Luminescent layer coating solution B was prepared by changing 1,2-dimethoxyethane to bis (2-methoxyethyl) ether (boiling point 162 ° C.), and the annealing temperature was 165 A light emitting layer single film was formed in the same manner as in Example 1-1 except that the temperature was changed to ° C.

(Comparative Example 1-1)
A light emitting layer single film was formed in the same manner as in Example 1-1 except that the light emitting layer coating solution C was prepared without adding the antioxidant described in Example 1-1.

<Production of organic electroluminescence device>
After depositing ITO (Indium Tin Oxide) as a positive electrode on a 0.7 mm thick, 25 mm square glass substrate to a thickness of 150 nm, etching and cleaning were performed. The substrate on which the ITO film was formed was placed in a cleaning container, subjected to ultrasonic cleaning in 2-propanol, and then subjected to UV-ozone treatment for 30 minutes. The following layers were formed on this glass substrate.
Note that spin coating, drying, and annealing were performed in a glove box (dew point -60 ° C., oxygen concentration 10 ppm).
Next, on the anode (ITO), PTPDES represented by the above structural formula (manufactured by Chemipro Kasei Co., Ltd., weight average molecular weight = 13000. N represents the number of repetitions of the structure in parentheses and is an integer.) 2 parts by mass Is spin-coated with a hole injection layer coating solution dissolved or dispersed in 98 parts by mass of cyclohexanone for electronics industry (manufactured by Kanto Chemical), dried at 120 ° C. for 10 minutes, and annealed at 160 ° C. for 60 minutes. A hole injection layer having a thickness of 40 nm was formed.

Example 1-2
On the formed hole injection layer, a light emitting layer made of the light emitting layer coating solution A was formed in the same manner as in Example 1-1.

(Example 2-2)
On the formed hole injection layer, a light emitting layer made of the light emitting layer coating solution B was formed in the same manner as in Example 2-1.

(Comparative Example 1-2)
On the formed hole injection layer, a light emitting layer made of the light emitting layer coating liquid C was formed in the same manner as in Comparative Example 1-1.

(Electron transport layer / electron injection layer / cathode / sealing)
Next, BAlq (Bis- (2-methyl-8-quinolinolato) -4- (phenyl-phenolate) -aluminum- (III)) was deposited on the light-emitting layer by a vacuum deposition method, thereby forming an electron having a thickness of 40 nm. A transport layer was formed.

Next, lithium fluoride (LiF) was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm.
Next, metal aluminum was vapor-deposited on the electron injection layer to form a cathode having a thickness of 70 nm.
The produced laminate was put in a glove box substituted with argon gas, and sealed using a stainless steel sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.).

(Evaluation of device performance)
<Measurement of external quantum efficiency>
Using a source measure unit 2400 manufactured by Toyo Technica Co., Ltd., a direct current voltage was applied to each element to emit light. The emission spectrum and luminance were measured using a spectrum analyzer SR-3 manufactured by Topcon Corporation, and the external quantum efficiency at a current of 10 mA / cm ² was calculated by the luminance conversion method based on these numerical values.
Results of PL quantum yield measured in Examples 1-1, 2-1 and Comparative Example 1-1, and external quantum measured for devices prepared in Examples 1-2, 2-2 and Comparative Example 1-2 The efficiency results are shown in Examples 1 and 2 and Comparative Example 1 in Table 1 below.

As is clear from the results in Table 1, the light emitting layer coating solution to which the antioxidant according to the present invention was added was used for Comparative Example 1 in which the light emitting layer coating solution to which the antioxidant according to the present invention was not added was used. Examples 1 and 2 were excellent in both PL quantum yield and external quantum efficiency.

(Storage stability of luminescent layer coating solution)
(Example 3)
A mixed solvent D in which 48 parts by mass of butyl lactate, 32 parts by mass of 2-n-butoxyethanol, and 20 parts by mass of an antioxidant: bis (2-methoxyethyl) ether were prepared. A light-emitting layer coating solution D was prepared by dissolving 98 parts by mass of the mixed solvent D, 1.8 parts by mass of the carbazole host having the above structural formula H-1 and 0.2 parts by mass of the Ir complex having the following structural formula E-2. .

(Comparative Example 2)
A light emitting layer coating solution E was prepared in the same manner as in Example 3 except that a mixed solvent E was prepared by mixing 60 parts by mass of butyl lactate and 40 parts by mass of 2-n-butoxyethanol without adding an antioxidant. did.

<Storage stability test>
After preparing each coating solution, molecular sieve (trade name: Molecular Sieve 3A 1/16, manufactured by Wako Pure Chemical Industries, Ltd.) is added and prepared by filtering using a syringe filter with a pore size of 0.22 μm in a glove box. The light emitting layer coating solution was spin coated in a glove box, dried at 120 ° C. for 30 minutes and annealed at 200 ° C. for 10 minutes to form a light emitting layer single film having a thickness of 50 nm on a glass substrate.
The coating liquids D and E were stored for 3 months in a glove box having an oxygen concentration of 10 ppm or less and a dew point of -60 ° C. or less using a light-shielded bottle. Filter again using a syringe filter with a pore size of 0.22 μm in the glove box, spin coat in the glove box, dry at 120 ° C. for 30 minutes and anneal at 200 ° C. for 10 minutes to emit light with a thickness of 50 nm A single layer film was formed on a glass substrate.
Examples 1-1, 2-1 and Comparative Examples for the light-emitting layer single film formed after the preparation of the light-emitting layer coating liquid and the light-emitting layer single film formed by the light-emitting layer coating liquid stored for 3 months after the preparation The PL quantum yield was measured in the same manner as in 1-1. The results are shown in Table 2 as “residual rate” as the ratio of “3 months” to “initial” after preparation, “3 months” after storage for 3 months, and “initial” values. It was.

As is clear from the results in Table 2, the light emitting layer coating solution added with the antioxidant according to the present invention was used for Comparative Example 2 using the light emitting layer coating solution without adding the antioxidant according to the present invention. Example 3 was excellent in storage stability.

(IJ discharge test)
Dimatics material printer: DMP-2831 (manufactured by FUJIFILM Corporation) was filled with the light emitting layer coating liquid D, and an IJ discharge test was conducted.
As a result, it was confirmed that droplets could be discharged from the nozzle without maintenance (purge process).

[Addition of antioxidant to hole injection layer coating solution]
Example 4
<Production of organic electroluminescence device>
After depositing ITO (Indium Tin Oxide) as a positive electrode on a 0.7 mm thick, 25 mm square glass substrate to a thickness of 150 nm, etching and cleaning were performed. The substrate on which the ITO film was formed was placed in a cleaning container, subjected to ultrasonic cleaning in 2-propanol, and then subjected to UV-ozone treatment for 30 minutes. The following layers were formed on this glass substrate.
Note that spin coating, drying, and annealing were performed in a glove box (dew point -60 ° C., oxygen concentration 10 ppm).
Next, on the anode (ITO), PTPDES represented by the above structural formula (manufactured by Chemipro Kasei Co., Ltd., weight average molecular weight = 13000. N represents the number of repetitions of the structure in parentheses and is an integer.) 2 parts by mass Was spin-coated with a hole injection layer coating solution dissolved in or dispersed in 80 parts by mass of cyclohexanone for electronics industry (manufactured by Kanto Chemical Co., Ltd.) and 18 parts by mass of bis (2-methoxyethyl) ether, and then at 120 ° C. for 10 minutes. A hole injection layer having a thickness of 40 nm was formed by drying and annealing at 165 ° C. for 60 minutes.
Next, as the light emitting layer, the host compound H-1 and an Ir complex of the following structural formula E-3 were formed at a mass ratio of 95: 5 and a thickness of 30 nm by vacuum deposition.

(Electron transport layer / electron injection layer / cathode / sealing)
Next, BAlq (Bis- (2-methyl-8-quinolinolato) -4- (phenyl-phenolate) -aluminum- (III)) having the above structure is deposited on the light emitting layer by a vacuum deposition method. A 40 nm electron transport layer was formed.

(Comparative Example 3)
An organic electroluminescent device was produced in the same manner as in Example 4 except that bis (2-methoxyethyl) ether was not added.

(Evaluation of element durability)
<Measurement of external quantum efficiency>
For the devices fabricated in Example 4 and Comparative Example 3, the external quantum efficiency was measured in the same manner as in Examples 1-2, 2-2 and Comparative Example 1-2.
<Driving durability>
The current density was adjusted so that the luminance was 500 cd / m ² , and the time until the luminance was reduced by half was measured.
The above results are shown in Table 3.

As is apparent from the results in Table 3, the hole injection layer coating with the addition of the antioxidant according to the present invention was performed on the comparative example 3 using the hole injection layer coating solution without the addition of the antioxidant according to the present invention. Example 4 using the liquid was excellent in both external quantum efficiency and durability.

[Addition of antioxidant to light-emitting layer coating solution]
<Measurement of PL quantum yield>
A quartz glass substrate having a thickness of 1.1 mm and a 25 mm square was alkali washed and rinsed, and then ultrasonically washed in 2-propanol, followed by UV-ozone treatment for 30 minutes. A light emitting layer single film was formed on this glass by the method described below using the light emitting layer coating solutions prepared in Examples 5-1 and 6-1 and Comparative Example 4-1.
Using an absolute PL quantum yield measuring apparatus C9920-02 (manufactured by Hamamatsu Photonics Co., Ltd.), the PL quantum yield of the formed light emitting layer single film was measured. As a reference, quartz glass on which no film was formed was used.

Example 5-1
A mixed solvent F in which 10 parts by mass of an antioxidant: propylene glycol dimethyl ether (boiling point 97 ° C.) was dissolved in 90 parts by mass of 2-butanone for electronic industry was prepared. A light emitting layer coating solution F was prepared by dissolving 98 parts by mass of a mixed solvent F, 1.8 parts by mass of a carbazole host having the following structural formula H-2, and 0.2 parts by mass of an Ir complex having the following structural formula E-4. .
Thereafter, a light emitting layer single film was formed in the same manner as in Example 1-1.

Example 6-1
A mixed solvent G was prepared by dissolving 5 parts by mass of an antioxidant: triethanolamine (boiling point 208 ° C.) in 95 parts by mass of 2-butanone for electronics industry. A light emitting layer coating solution G was prepared by dissolving 98 parts by mass of the mixed solvent G, 1.8 parts by mass of the carbazole host having the structural formula H-2, and 0.2 parts by mass of the Ir complex having the structural formula E-4. .
Luminescence prepared by adding molecular sieve (trade name: Molecular sieve 3A 1/16, manufactured by Wako Pure Chemical Industries, Ltd.) to the light-emitting layer coating solution G and filtering with a syringe filter having a pore size of 0.22 μm in a glove box. The layer coating solution is spin-coated in a glove box (dew point -60 ° C., oxygen concentration 10 ppm), dried at 120 ° C. for 30 minutes and vacuum dried at 160 ° C. for 20 minutes. Formed on a substrate.

(Comparative Example 4-1)
A light emitting layer single film was formed in the same manner as in Example 5-1, except that the light emitting layer coating solution H was prepared without adding the antioxidant described in Example 5-1.

<Production of organic electroluminescence device>
(Example 5-2)
An organic electroluminescent element was produced in the same manner as in Example 1-2, except that a light emitting layer composed of the light emitting layer coating solution F was formed in the same manner as in Example 5-1.

(Example 6-2)
An organic electroluminescent element was produced in the same manner as in Example 1-2, except that a light emitting layer composed of the light emitting layer coating solution G was formed in the same manner as in Example 6-1.

(Comparative Example 4-2)
An organic electroluminescent element was produced in the same manner as in Example 1-2, except that a light emitting layer composed of the light emitting layer coating solution H was formed as in Comparative Example 4-1.

(Evaluation of device performance)
<Measurement of external quantum efficiency>
Using a source measure unit 2400 manufactured by Toyo Technica Co., Ltd., a direct current voltage was applied to each element to emit light. The emission spectrum and luminance were measured using a spectrum analyzer SR-3 manufactured by Topcon Corporation, and the external quantum efficiency at a current of 10 mA / cm ² was calculated by the luminance conversion method based on these numerical values.
Results of PL quantum yield measured in Examples 5-1 and 6-1 and Comparative Example 4-1, and external quantum measured for devices prepared in Examples 5-2 and 6-2 and Comparative Example 4-2 The efficiency results are shown in Examples 5 and 6 and Comparative Example 4 in Table 4 below.

As is clear from the results in Table 4, the light emitting layer coating solution added with the antioxidant according to the present invention was used for Comparative Example 4 using the light emitting layer coating solution not added with the antioxidant according to the present invention. Examples 5 and 6 were excellent in both PL quantum yield and external quantum efficiency.

(Storage stability of luminescent layer coating solution)
(Example 7)
A mixed solvent I in which 95 parts by mass of 2-butanone for electronic industry and an antioxidant: oxalic acid (decomposition temperature 189.5 ° C.) were dissolved was prepared. A light emitting layer coating solution I was prepared by dissolving 98 parts by mass of the mixed solvent I, 1.82 parts by mass of the following structural formula host H-3, and 0.18 parts by mass of an Ir complex having the following structural formula E-5.

(Comparative Example 5)
A light emitting layer coating solution J was prepared in the same manner as in Example 7 except that the antioxidant described in Example 7 was not added.

<Storage stability test>
Evaluation was performed in the same manner as in Example 3 and Comparative Example 2 except that the annealing treatment at 200 ° C. for 10 minutes was changed to the annealing treatment at 210 ° C. for 20 minutes. The results are shown in Table 5.

As is clear from the results in Table 5, the light emitting layer coating solution added with the antioxidant according to the present invention was used for Comparative Example 5 using the light emitting layer coating solution not added with the antioxidant according to the present invention. Example 7 was excellent in storage stability.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (Japanese Patent Application No. 2010-223261) filed on Sep. 30, 2010, the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 2 ... Substrate 3 ... Anode 4 ... Hole injection layer 5 ... Hole transport layer 6 ... Light emitting layer 7 ... Hole block layer 8 ... Electron transport layer 9 ...・ Cathode 10: Organic electroluminescent device

Claims

An organic electroluminescent composition comprising an organic material (B) and a solvent (C), a liquid containing an antioxidant (A) that can be evaporated or decomposed by heating. A composition for an organic electroluminescence device, wherein the antioxidant (A) evaporates or decomposes by heating at the time of film formation of the composition in the production of the device.
The composition for organic electroluminescent elements according to claim 1, wherein the antioxidant (A) is evaporated or decomposed by heating at 80 ° C to 220 ° C.
The composition for organic electroluminescent elements according to claim 1 or 2, wherein the antioxidant (A) is liquid at 25 ° C.
The composition for an organic electroluminescent element according to any one of claims 1 to 3, wherein the antioxidant (A) is an alkylene glycol derivative, an amino alcohol derivative or oxalic acid.
The composition for an organic electroluminescent element according to any one of claims 1 to 4, comprising a light emitting material and a host material as the organic material (B).
The composition for an organic electroluminescent element according to claim 5, wherein the light emitting material is an iridium complex, and the host material is a carbazole derivative.
The composition for organic electroluminescent elements according to any one of claims 1 to 4, comprising a charge transport material as the organic material (B).
The organic electroluminescence according to claim 5 or 6, containing at least one selected from the group consisting of 2-butanone, butyl lactate, amyl lactate, isoamyl lactate and 2-n-butoxyethanol as the solvent (C). Device composition.
The composition for organic electroluminescent elements according to claim 7, comprising cyclohexanone as the solvent (C).
A film formed by applying the composition according to any one of claims 1 to 9 and heating the applied composition.
A light emitting layer formed by applying the composition according to any one of claims 5, 6 and 8, and heating the applied composition.
A charge transport layer formed by applying the composition according to claim 7 or 9 and heating the applied composition.
The organic electroluminescent element which has a light emitting layer of Claim 11.
An organic electroluminescent device having the charge transport layer according to claim 12.
A method for forming a light emitting layer, comprising applying the composition according to any one of claims 5, 6, and 8, and heating the applied composition.
A method for forming a charge transport layer, comprising applying the composition according to claim 7 or 9 and heating the applied composition.