JP6922232B2 - Polymers, compositions for organic electroluminescent devices, methods for manufacturing organic electroluminescent devices, methods for manufacturing organic EL display devices, and methods for manufacturing organic EL lighting. - Google Patents

Description

The present invention relates to a polymer, and more particularly, a polymer useful as a charge transporting material for an organic electroluminescent element, a composition for an organic electroluminescent element containing the polymer, and a layer formed by using the composition. The present invention relates to an organic electroluminescent element including the above, and an organic EL display device and organic EL lighting having the organic electroluminescent element.

Examples of the method for forming the organic layer in the organic electroluminescent device include a vacuum vapor deposition method and a wet film deposition method. Since the vacuum vapor deposition method is easy to stack, it has the advantages of improving charge injection from the anode and / or cathode and facilitating containment of excitons in the light emitting layer. On the other hand, the wet film forming method does not require a vacuum process, it is easy to increase the area, and by using a coating liquid in which a plurality of materials having various functions are mixed, a plurality of materials having various functions can be easily obtained. There are advantages such as being able to form a layer containing the above materials.

However, since the wet film deposition method is difficult to stack, the drive stability is inferior to that of the device by the vacuum vapor deposition method, and the current situation is that the drive stability has not reached the practical level except for a part.
Therefore, a charge-transporting polymer having a crosslinkable group is desired and is being developed for laminating by a wet film forming method. For example, Patent Documents 1 to 3 disclose an organic electroluminescent device containing a polymer having a specific repeating unit and laminated by a wet film forming method.

International Publication No. 2009/123269 Japanese Unexamined Patent Publication No. 2013-045986 International Publication No. 2013/191088

However, when the π-conjugated systems of the main chain structures of these polymers described in Patent Documents 1 to 3 aggregate and J-associate, new remarkably low singlet and triplet excited levels are generated. This may inactivate the singlet excited state and the triplet excited state, resulting in a decrease in the light emission efficiency of the fluorescent light emitting element and the phosphorescent light emitting element. The drive voltage of the organic electroluminescent device composed of such a polymer is high, the luminous efficiency is low, and the drive life is short.

Therefore, the present invention has high singlet-excited and triplet-excited levels, is excellent in electrochemical stability, can be laminated with three or more layers, is less likely to be decomposed by energization, and has a homogeneous film quality. It is an object of the present invention to provide a polymer capable of providing the above, and to provide an organic electroluminescent element material containing the polymer and a composition for an organic electroluminescent element.
Another object of the present invention is to provide an organic electroluminescent element having high luminous efficiency and high drive stability, and a display device and a lighting device having the same.

As a result of diligent studies, the present inventors have found that the above problems can be solved by using a polymer having a specific repeating unit, and have completed the present invention.
That is, the gist of the present invention is as follows [1] to [11].
[1] A polymer having a repeating unit represented by the following formula (1).

(In the formula, Ar ¹ , Ar ² , and Ar ³ each independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent ^{, and R 1 has a substituent.} Represents an alkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group, which may be used.)
[2] The polymer according to claim 1, which has a crosslinkable group.
[3] The polymer according to [1] or [2], wherein ^{Ar 3 is a 2-fluorenyl group which may have a substituent.}
[4] The polymer according to [2] or [3], wherein the crosslinkable group is a group containing a cyclobutene ring fused to an aromatic ring.
[5] The polymer according to any one of [1] to [4], which has a weight average molecular weight (Mw) of 5,000 or more and a dispersity (Mw / Mn) of 3.5 or less.
[6] A composition for an organic electroluminescent device, which contains the polymer according to any one of [1] to [5].
[7] An organic electroluminescent device having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, wherein the organic layer is the composition for an organic electroluminescent device according to [6]. An organic electroluminescent device comprising a layer formed by a wet film forming method using the above.
[8] The organic electroluminescent device according to [7], wherein the layer formed by the wet film forming method is at least one of a hole injection layer and a hole transport layer.
[9] A hole injection layer, a hole transport layer and a light emitting layer are included between the anode and the cathode, and the hole injection layer, the hole transport layer and the light emitting layer are all formed by a wet film forming method. The organic electroluminescent device according to [7] or [8].
[10] An organic EL display device comprising the organic electroluminescent device according to any one of [7] to [9].
[11] An organic EL illumination comprising the organic electroluminescent device according to any one of [7] to [9].

The polymer of the present invention can maintain high singlet and triplet excited levels, and the layer containing the polymer of the present invention can carry a current even at a relatively low voltage, and can generate an exciter. Since it is difficult to deactivate, according to the present invention, an organic electroluminescent element having high current efficiency, low drive voltage, and long drive life can be obtained.

It is the schematic of the cross section which shows the structural example of the organic electroluminescent element of this invention.

Hereinafter, embodiments of the present invention will be described in detail, but the description of the constituent elements described below is an example (representative example) of the embodiments of the present invention, and the present invention is described as long as the gist of the present invention is not exceeded. Not specified in the content of.
<Polymer of the present invention>
The polymer of the present invention is characterized by having a repeating unit represented by the following formula (1).

In the formula, Ar ¹ , Ar ² , and Ar ³ each independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent ^{, and R 1 has a substituent.} Represents an alkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group which may be present.

[Ar ¹ , Ar ² , Ar ³ and R ¹ ]
^{In Ar 1} , Ar ² , and Ar ³ in the repeating unit represented by the above formula (1), examples of the aromatic hydrocarbon group which may have a substituent include a benzene ring, a naphthalene ring, and an anthracene ring. , Phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysen ring, triphenylene ring, acenaphthene ring, fluorantene ring, fluorene ring, etc. Can be mentioned.

^{In Ar 1} , Ar ² , and Ar ³ in the repeating unit represented by the above formula (1), examples of the aromatic heterocyclic group which may have a substituent include a furan ring, a benzofuran ring, and a thiophene ring. , Benzentiphene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyroloymidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrol ring, thienothiophene ring, flopyrol ring, flofuran ring, Thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxalin ring, phenanthridin ring, benzo Examples thereof include monovalent groups of 5- or 6-membered monocyclic rings or 2-4 fused rings such as imidazole rings, perimidine rings, quinazoline rings, quinazolinone rings, and azulene rings.

Since Ar ¹ and Ar ² have a higher effect of inhibiting charge transportability and the spread of the π-conjugated system, aromatic hydrocarbon groups are preferable among the above, and among them, a benzene ring, a naphthalene ring, a phenanthrene ring, and a fluorene ring. Is more preferable, and a benzene ring is particularly preferable.
As the ^{substituents that Ar 1} and Ar ² may have, an aromatic hydrocarbon group is preferable from the viewpoint of excellent charge transportability. For example, a 6-membered monocyclic ring such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, a fluorene ring, or the like. Examples thereof include monovalent groups of 2-5 fused rings.

Further, ^{as the substituent that Ar 1} and Ar ² may have, an alkyl group is preferable from the viewpoint of excellent molecular solubility. For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group. , Dodecyl group, etc., which usually have 1 or more carbon atoms and usually 24 or less carbon atoms, and examples thereof include linear, branched, or cyclic alkyl groups. Of these, sec-butyl group, tert-butyl group, n-hexyl group and n-octyl group are particularly preferable.

Ar ³ is preferably an aromatic hydrocarbon group from the viewpoint of excellent charge transportability and durability, and among them, a monovalent group of a benzene ring and a fluorene ring, that is, a phenyl group and a fluorenyl group are more preferable, and fluorenyl. Groups are more preferred, and 2-fluorenyl groups are particularly preferred. From the viewpoint of excellent solubility, it is preferable to have a substituent at the 9-position of the 2-fluorenyl group, and the substituents include n-butyl group, i-butyl group, sec-butyl group, tert-butyl group and n. A linear, branched, or cyclic alkyl group having 4 or more and 12 or less carbon atoms, such as a-hexyl group, cyclohexyl group, n-octyl group, and dodecyl group, is preferable, and a direct group having 4 or more and 12 or less carbon atoms is preferable. The alkyl or n-hexyl group of the chain is more preferred, and the n-hexyl group is particularly preferred.

Examples of the aromatic hydrocarbon group and the aromatic heterocyclic group which may have a substituent ^{in R 1} in the repeating unit represented by the above formula (1) ^{include the above Ar 1} , Ar ² and. Examples of the alkyl group which is the same as Ar ³ and may have a substituent include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group and sec. A linear, branched, or cyclic group having a carbon number of 1 or more and usually 24 or less, such as a-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, and dodecyl group. Alkyl groups can be mentioned.

In R ^1, an alkyl group, the substituent that may be possessed by the aromatic hydrocarbon group or an aromatic heterocyclic group, as long as it does not significantly reduce the characteristics of the polymer is not particularly limited, for example, , The group selected from the following substituent group Z is mentioned, and an alkyl group, an alkoxy group, an aromatic hydrocarbon group, and an aromatic heterocyclic group are preferable.

[Substituent group Z]
For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, dodecyl group and the like. A linear, branched, or cyclic alkyl group usually having 1 or more carbon atoms, usually 24 or less, preferably 12 or less;
An alkenyl group having a carbon number of usually 2 or more, usually 24 or less, preferably 12 or less, such as a vinyl group;
For example, an alkynyl group having 2 or more carbon atoms, usually 24 or less, preferably 12 or less, such as an ethynyl group;
A haloalkyl group having a carbon number of usually 1 or more, usually 12 or less, preferably 6 or less, such as a trifluoromethyl group;
For example, an aromatic hydrocarbon group having 6 or more carbon atoms, usually 36 or less, preferably 24 or less, such as a phenyl group or a naphthyl group;
For example, an aromatic heterocyclic group having a carbon number of usually 3 or more, preferably 4 or more, and usually 36 or less, preferably 24 or less, such as a thienyl group or a pyridyl group.

Further, each of the above-mentioned substituents may further have a substituent, and examples of these substituents include the same ones as the above-mentioned Substituents (Substituent Group Z).
As shown in the formula (1), the polymer of the present invention inhibits the spread of the π-conjugated system by substituting metaphenylene instead of paraphenylene at the 3,6-position of carbazole, and the energy of the molecule. It is estimated that the gap becomes wider and the singlet and triplet excited levels can be maintained high. Further, since the polymer of the present invention has 9-phenylcarbazole in addition to the aromatic ring between the two arylamine nitrogen atoms, the effect of improving the charge injection property of carbazole effectively charges the light emitting layer. It is thought to be injected. Therefore, the layer containing the polymer of the present invention can pass a current even at a relatively low voltage, and it is difficult to deactivate excitons, so that the luminous efficiency of the obtained organic electroluminescent device is high.

Further, in the polymer of the present invention, HOMO spreads over the fluorene ring existing in the side chain and the two benzene rings on both sides thereof, so that HOMO is relatively distributed around the nitrogen atom which is vulnerable to electrons and excitons. Has excellent durability.
Further, the layer obtained by wet film formation using the composition for an organic electroluminescent device containing the polymer of the present invention is flat without cracks or the like. According to the organic electroluminescent device in the present invention, the brightness is high and the luminous efficiency is high.

Further, since the polymer of the present invention is excellent in electrochemical stability, the element including the layer formed by using the polymer is a flat panel display (for example, for an OA computer or a wall-mounted television) or an in-vehicle display element. , Light sources that take advantage of the characteristics of mobile phone displays and surface emitters (for example, light sources for copiers, backlight sources for liquid crystal displays and instruments), display boards, indicator lights, and their technical value Is a big one.

[Another repeating unit]
The polymer of the present invention may contain a repeating unit different from the repeating unit represented by the formula (1).
As another repeating unit, the repeating unit represented by the formula (2) is preferable in terms of charge transportability and durability.

In the formula (2), Ar ⁴ and Ar ⁵ each independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent. A plurality of the aromatic hydrocarbon groups and aromatic heterocyclic groups may be linked directly or via a linking group.
Specific examples of the aromatic hydrocarbon group and the aromatic hydrocarbon group in Ar ⁴ and Ar ^{5 include the same as those in the cases of Ar 1} , Ar ² , and Ar ³ , but in particular, the charge transport property. ^{In addition to durability, Ar 5} in the formula (2) is preferably a group represented by the following formula (3) in that it is excellent in hole injection from the anode side.

In equation (3), m represents an integer of 1-3.
Further, since the triplet excitation level can be maintained high and the excitation element confinement effect is high, the emission efficiency of the obtained organic electric field light emitting element is high. Therefore, Ar ⁵ in the equation (2) is expressed by the following equation (4). ) Is preferably an aromatic hydrocarbon group or an aromatic heterocyclic group linked via a linking group.

In equation (4), p represents an integer of 1-10. R ² and R ³ each independently represent an alkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, which may have a hydrogen atom or a substituent. When a ^{plurality of R 2} and R ³ exist, they may be the same or different.
Specific examples of the alkyl group, aromatic hydrocarbon group, aromatic heterocyclic group in R ^{2 and R 3} , and the ^{substituent that these groups may have include, for example, Ar 1} , Ar ² , and Ar ^{3 described above.} The same as in the case of.

[Content of repeating unit]
In the polymer of the present invention, the content of the repeating unit represented by the formula (1) is not particularly limited, but it is preferably contained in the polymer in an amount of 30 mol% or more, more preferably 50 mol% or more. , 70 mol% or more is particularly preferable.

[Crosslinkable group]
The polymer of the present invention preferably has a crosslinkable group. A crosslinkable group is a group that forms a new chemical bond by reacting with a group constituting another molecule located in the vicinity of the crosslinkable group by irradiation with heat and / or active energy rays. To say. In this case, the reacting group may be the same group as the crosslinkable group or a different group.

The crosslinkable group in the polymer of the present invention may be present in a repeating unit different from the repeating unit represented by the formula (1), and Ar ¹ , Ar ² , Ar ^{3 in the formula (1).} , R ¹ may be present as a substituent. In order to enhance the hole injection transport capacity and durability, it is preferable that the crosslinkable group is present in a repeating unit different from the repeating unit represented by the formula (1), and the side chains Ar ⁴ , R. It is more preferable to have a crosslinkable group at ^{3 because the crosslink reaction can easily proceed.}
By having a crosslinkable group, it is possible to make a large difference in solubility in an organic solvent before and after a reaction (poor solubility reaction) caused by irradiation with heat and / or active energy rays.

[Crosslinkable group T]
Specific examples of the crosslinkable group include the groups shown in the following crosslinkable group group T.

(In the formula, R ^{4 to} R ¹⁰ are aromatic hydrocarbon groups that may have a hydrogen atom, an alkyl group, an alkoxy group or a substituent, or an aromatic heterocyclic group that may have a substituent. show.)
The alkyl group of R ^{4 to} R ¹⁰ is usually preferably a linear or branched chain alkyl group having 6 or less carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, or n. -Butyl group, isobutyl group, etc. More preferably, it is a methyl group or an ethyl group. When the number of carbon atoms is 6 or less, the cross-linking reaction is not sterically inhibited, and the insolubilization of the film tends to occur easily.

The alkoxy group of R ^{4 to} R ¹⁰ is usually preferably a linear or branched chain alkoxy group having 6 or less carbon atoms, for example, a methoxy group, an ethoxy group, an n-propoxy group, a 2-propoxy group, or n. -Butoxy group, etc. More preferably, it is a methoxy group or an ethoxy group. When the number of carbon atoms is 6 or less, the cross-linking reaction is not sterically inhibited, and the insolubilization of the film tends to occur easily.

The ^{aromatic hydrocarbon group which may have a substituent of R 4 to} R ¹⁰ includes, for example, a single ring of 6-membered rings such as a benzene ring and a naphthalene ring having one free valence. Examples thereof include 2 to 5 fused rings. In particular, a benzene ring having one free valence is preferable.
Of these, groups that undergo a cycloaddition reaction, such as a benzocyclobutene ring and a cyclobutenenaphthalene ring having a monovalent free valence, are preferable in that they further improve the electrochemical stability of the device.

Among the crosslinkable groups, a group containing a cyclobutene ring fused to an aromatic ring having a monovalent free valence is preferable, and a cyclobutenenaphthalene ring is particularly preferable, because the structure after crosslinking is particularly stable. ..
In the polymer of the present invention, the crosslinkable group may be directly attached to an aromatic hydrocarbon group, an aromatic heterocyclic group and / or a linking group, or an aromatic hydrocarbon group and / or an aromatic group. It may be directly bonded to a group other than the heterocyclic group, or may be bonded to these groups via an arbitrary divalent group. The optional divalent group, -O- group, -C (= O) - group and (which may have a substituent) -CH ₂ -. 1 to a group selected from the group in any order A group formed by connecting 30 groups is preferable.

[Number of crosslinkable groups]
It is preferable that the crosslinkable group of the polymer of the present invention has a large number in that it is sufficiently insolubilized by crosslinking and that another layer can be easily formed on the crosslinkable group by a wet film forming method. On the other hand, it is preferable that the number of crosslinkable groups is small in that cracks are unlikely to occur in the formed layer, unreacted crosslinkable groups are unlikely to remain, and the organic electroluminescent device tends to have a long life.

In the polymer of the present invention, the number of crosslinkable groups present in one polymer chain is preferably 1 or more on average, more preferably 2 or more on average, and preferably 200 or less, more preferably 100 or less.
Further, the number of crosslinkable groups contained in the polymer of the present invention can be expressed by the number per 1000 molecular weight of the polymer.

When the number of crosslinkable groups contained in the polymer of the present invention is expressed as the number per 1000 molecular weight of the polymer, it is usually 3.0 or less, preferably 2.0 or less, more preferably 1 per 1000 molecular weight. It is 0.0 or less, and is usually 0.01 or more, preferably 0.05 or more.
When the number of crosslinkable groups is within the above range, cracks and the like are unlikely to occur, and a flat film can be easily obtained. Further, since the cross-linking density is appropriate, there are few unreacted cross-linking groups remaining in the layer after the cross-linking reaction, and it is unlikely to affect the life of the obtained device.

Further, since the poor solubility in the organic solvent after the crosslinking reaction is sufficient, it is easy to form a multilayer laminated structure by the wet film forming method.
Here, the number of crosslinkable groups per 1000 molecular weight of the polymer can be calculated from the molar ratio of the charged monomer at the time of synthesis and the structural formula, excluding the terminal groups thereof from the polymer. For example, in the case of the polymer 1 synthesized in Example 1 described later and represented by the following formula, the molecular weight of the repeating unit excluding the terminal group in the polymer 1 is 895.01 on average, and the crosslinkability The average number of groups is 0.118 per repeating unit. When this is calculated by simple proportionality, the number of crosslinkable groups per 1000 molecular weight is calculated to be 0.132.

[Molecular weight of polymer]
The weight average molecular weight (Mw) of the polymer of the present invention is usually 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, still more preferably 200,000 or less, and also. It is usually 2,500 or more, preferably 5,000 or more, more preferably 10,000 or more, still more preferably 30,000 or more.

When the weight average molecular weight of the polymer is not more than the above upper limit value, the solubility in a solvent is good, which is preferable in terms of film forming property. Further, when the weight average molecular weight of the polymer is at least the above lower limit value, the glass transition temperature, melting point and vaporization temperature of the polymer can be maintained high, which is preferable in terms of heat resistance.
The number average molecular weight (Mn) of the polymer of the present invention is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and usually 2,000 or more, preferably 2,000 or more. It is 4,000 or more, more preferably 8,000 or more, and even more preferably 20,000 or more.

Further, the dispersity (Mw / Mn) in the polymer of the present invention is usually 5.0 or less, preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. Since the smaller the value of the dispersion, the better, the lower limit is ideally 1. When the dispersity of the polymer is not more than the above upper limit value, purification is easy, and solubility in a solvent and charge transporting ability are good.

[Concrete example]
Specific examples of the polymer of the present invention are shown below, but the polymer of the present invention is not limited thereto. The numbers in the chemical formula represent the molar ratio of the repeating unit.
These polymers may be random copolymers, alternate copolymers, block copolymers, graft copolymers, or the like, and the order of arrangement of the monomers is not limited.

[Method for producing polymer]
The method for producing the polymer of the present invention is not particularly limited, and is arbitrary as long as the polymer of the present invention can be obtained. For example, it can be produced by a polymerization method by Suzuki reaction, a polymerization method by Grignard reaction, a polymerization method by Yamamoto reaction, a polymerization method by Ullmann reaction, a polymerization method by Buchwald-Hartwig reaction, or the like.

In the case of the polymerization method by the Ullmann reaction and the polymerization method by the Buchwald-Hartwig reaction, for example, a primary aminoaryl represented by the formula (1a) and an aryl dihalide represented by the formula (2a) (X is I, Br, Cl). , F, etc.), to synthesize the polymer of the present invention.

(In the formula, X represents a halogen atom, and Ar ¹ , Ar ² , Ar ³ , and R ¹ are synonymous with the above.)
In the above polymerization method, the reaction step with the halide is usually carried out in the presence of a base such as potassium carbonate, tert-butoxysodium or triethylamine. Further, if necessary, it can be carried out in the presence of a transition metal catalyst such as copper or a palladium complex. Further, the reaction step with the boron derivative can be carried out in the presence of a base such as a quaternary ammonium salt, potassium carbonate, tert-butoxysodium or triethylamine, and a transition metal catalyst such as copper or a palladium complex.

<Organic electroluminescent device material>
The polymer of the present invention can be particularly preferably used as an organic electroluminescent device material. That is, the polymer of the present invention is preferably an organic electroluminescent device material.
When the polymer of the present invention is used as an organic electroluminescent device material, it is preferably used as a material that forms at least one of a hole injection layer and a hole transport layer in an organic electroluminescent device, that is, a charge transport material.

When used as a charge transporting material, it may contain one kind of polymer of the present invention, or may contain two or more kinds in any combination and any ratio.
When at least one of the hole injection layer and the hole transport layer of the organic electroluminescent device is formed by using the polymer of the present invention, the inclusion of the polymer of the present invention in the hole injection layer and / or the hole transport layer. The amount is usually 1 to 100% by weight, preferably 5 to 100% by weight, and more preferably 10 to 100% by weight. The above range is preferable because the charge transportability of the hole injection layer and / or the hole transport layer is improved, the drive voltage is reduced, and the drive stability is improved.

When the polymer of the present invention is not 100% by weight in the hole injecting layer and / or the hole transporting layer, the hole transporting as a component constituting the hole injecting layer and / or the hole transporting layer will be described later. Examples include sex compounds.
Further, since the organic electroluminescent device can be easily manufactured, the polymer of the present invention is preferably used for the organic layer formed by the wet film forming method.

<Composition for organic electroluminescent device>
The composition for an organic electroluminescent device of the present invention contains the polymer of the present invention. The composition for an organic electroluminescent device of the present invention may contain one type of the polymer of the present invention, or may contain two or more types in an arbitrary combination and an arbitrary ratio. good.

[Polymer content]
The content of the polymer of the present invention in the composition for an organic electroluminescent device of the present invention is usually 0.01 to 70% by weight, preferably 0.1 to 60% by weight, and more preferably 0.5 to 50% by weight. %.
When it is within the above range, defects are unlikely to occur in the formed organic layer and uneven film thickness is unlikely to occur, which is preferable.
The composition for an organic electroluminescent device of the present invention may contain a solvent or the like in addition to the polymer of the present invention.

[solvent]
The composition for an organic electroluminescent device of the present invention usually contains a solvent. The solvent is preferably one that dissolves the polymer of the present invention. Specifically, a solvent that dissolves the polymer of the present invention in an amount of usually 0.05% by weight or more, preferably 0.5% by weight or more, and more preferably 1% by weight or more at room temperature is preferable.

Specific examples of the solvent include aromatic solvents such as toluene, xylene, mesityrene and cyclohexylbenzene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene and o-dichlorobenzene; ethylene glycol dimethyl ether, ethylene glycol diethyl ether and propylene. Aliper ethers such as glycol-1-monomethyl ether acetate (PGMEA), 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, Ether-based solvents such as aromatic ethers such as 2,3-dimethylanisole and 2,4-dimethylanisole; aliphatic ester-based solvents such as ethyl acetate, n-butyl acetate, ethyl lactate and n-butyl lactate; phenyl acetate, Ester-based solvents such as phenyl propionate, methyl benzoate, ethyl benzoate, isopropyl benzoate, propyl benzoate, n-butyl benzoate and other aromatic esters; Examples thereof include organic solvents used in the composition for forming a hole transport layer and the composition for forming a hole transport layer.

As the solvent, one type may be used, or two or more types may be used in any combination and in any ratio.
Among them, as the solvent contained in the composition for an organic electroluminescent device of the present invention, a solvent having a surface tension at 20 ° C. of usually less than 40 dyn / cm, preferably 36 dyn / cm or less, more preferably 33 dyn / cm or less. Is preferable.

When a coating film is formed by a wet film forming method using the composition for an organic electroluminescent device of the present invention and the polymer of the present invention is crosslinked to form an organic layer, the affinity between the solvent and the substrate is high. preferable. This is because the uniformity of the film quality greatly affects the uniformity and stability of the light emission of the organic electroluminescent device. Therefore, the composition for an organic electroluminescent device used in the wet film forming method is required to have a low surface tension so that a more levelable and uniform coating film can be formed. Therefore, by using a solvent having a low surface tension as described above, a uniform layer containing the polymer of the present invention can be formed, and a uniform crosslinked layer can be formed, which is preferable.

Specific examples of the low surface tension solvent include the above-mentioned aromatic solvents such as toluene, xylene, mesityrene and cyclohexylbenzene, ester solvents such as ethyl benzoate, ether solvents such as anisole, trifluoromethoxyanisole and penta. Fluoromethoxybenzene, 3- (trifluoromethyl) anisole, ethyl (pentafluorobenzoate) and the like can be mentioned.

On the other hand, as the solvent contained in the composition for an organic electroluminescent device of the present invention, a solvent having a vapor pressure at 25 ° C. of usually 10 mmHg or less, preferably 5 mmHg or less, and usually 0.1 mmHg or more is preferable. .. By using such a solvent, a composition for an organic electroluminescent device suitable for the process of manufacturing an organic electroluminescent device by a wet film forming method and suitable for the properties of the polymer of the present invention can be prepared. ..

Specific examples of such a solvent include the above-mentioned aromatic solvents such as toluene, xylene and mesitylene, ether solvents and ester solvents.
By the way, moisture may cause deterioration of the performance of the organic electroluminescent element, and in particular, it may promote a decrease in brightness during continuous driving. Therefore, in order to reduce the water content remaining during the wet film formation as much as possible, among the above-mentioned solvents, those having a water solubility at 25 ° C. of 1% by weight or less are preferable, and those having a solubility of 0.1% by weight or less are preferable. Is more preferable.
The content of the solvent contained in the composition for an organic electroluminescent device of the present invention is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, and particularly preferably 80% by weight or more. .. When the content of the solvent is at least the above lower limit, the flatness and uniformity of the formed layer can be improved.

[Electron accepting compound]
When the composition for an organic electroluminescent device of the present invention is used for forming a hole injection layer, it preferably further contains an electron-accepting compound in terms of lowering the resistance.
As the electron-accepting compound, a compound having an oxidizing power and an ability to accept one electron from the polymer of the present invention is preferable. Specifically, a compound having an electron affinity of 4 eV or more is preferable, and a compound having an electron affinity of 5 eV or more is more preferable.
Examples of such an electron-accepting compound include a triarylboron compound, a metal halide, a Lewis acid, an organic acid, an onium salt, a salt of an arylamine and a metal halide, and a salt of an arylamine and a Lewis acid. Examples thereof include one kind or two or more kinds of compounds selected from the group consisting of two or more kinds.

Specifically, an onium salt substituted with an organic group such as 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium tetrafluoroborate (International Publication No. 2005/089024); chloride. High valence inorganic compounds such as iron (III) (Japanese Patent Laid-Open No. 11-251067), ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; tris (pentafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-313665) Aromatic boron compounds such as; fullerene derivatives, iodine and the like.

As such a compound, an element belonging to the 15th to 17th groups of the long-periodic periodic table (hereinafter, unless otherwise specified, the term "periodic table" refers to the long-periodic table). In addition, it is preferably an ionic compound having a structure in which at least one organic group is bonded by a carbon atom, and in particular, a compound represented by the following formula (5) is preferable.

(In the formula, R ¹¹ represents an organic group bonded to A ₁ ^{at a carbon atom, R 12} represents an arbitrary substituent. Even if R ¹¹ and R ¹² are bonded to each other to form a ring. good.)
The type of R ¹¹ is not particularly limited as long as it is an organic group having a carbon atom at the bonding portion with _{A 1, as long as it does not contradict the gist of the present invention.} The molecular weight of R ¹¹ is a value including a substituent and is usually in the range of 1000 or less, preferably 500 or less.

Preferred examples of R ¹¹ include an alkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, and an aromatic heterocyclic group from the viewpoint of delocalizing the positive charge. Of these, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferable because it delocalizes the positive charge and is thermally stable.
Examples of the alkyl group include linear, branched or cyclic alkyl groups having a carbon number of usually 1 or more, and usually 12 or less, preferably 6 or less. Specific examples include a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group and the like.

Examples of the alkenyl group include those having a carbon number of usually 2 or more, usually 12 or less, and preferably 6 or less. Specific examples include a vinyl group, an aryl group, a 1-butenyl group and the like.
Examples of the alkynyl group include those having a carbon number of usually 2 or more, usually 12 or less, and preferably 6 or less. Specific examples include an ethynyl group and a propargyl group.

The aromatic hydrocarbon group is a 5- or 6-membered monocyclic ring or a 2-5 condensed ring having one free valence, and a group capable of delocalizing a positive charge on the group. Can be mentioned. Specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, and a fluorene ring having one free valence. And so on.

The aromatic heterocyclic group is a 5- or 6-membered monocyclic ring or a 2-4 condensed ring having one free valence, and a group capable of delocalizing a positive charge on the group. Can be mentioned. Specific examples thereof include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, a triazole ring, an imidazole ring, an oxadiazole ring, an indol ring, and a carbazole ring, which have one free valence. , Pyrroylmidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, flopyrol ring, flofuran ring, thienofran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine Examples thereof include a ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a sinoline ring, a quinoxaline ring, a phenanthridin ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, and an azulene ring.

R ¹² is not particularly limited as long as it does not contradict the gist of the present invention. The molecular weight of R ¹² is a value including a substituent and is usually in the range of 1000 or less, preferably 500 or less.
Examples of R ¹² include an alkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group and an aryloxycarbonyl group. Examples thereof include an alkylcarbonyloxy group, an alkylthio group, an arylthio group, a sulfonyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfonyloxy group, a cyano group, a hydroxyl group, a thiol group and a silyl group.

Among them, _{an organic group having a carbon atom at the bonding portion with A 1} is preferable because of its high electron acceptability as ^{in R 11,} and examples thereof include an alkyl group, an alkenyl group, an alkynyl group, and an aromatic hydrocarbon group. Aromatic heterocyclic groups are preferred. In particular, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferable because it has high electron acceptability and is thermally stable.
Alkyl group R ^12, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, the aromatic heterocyclic group include the same as those described for R ¹¹ above.

Examples of the amino group include an alkylamino group, an arylamino group, an acylamino group and the like.
Examples of the alkylamino group include an alkylamino group having at least one alkyl group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less carbon atoms. Specific examples include a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group and the like.

Examples of the arylamino group include an arylamino group having one or more aromatic hydrocarbon groups or aromatic heterocyclic groups having usually 3 or more carbon atoms, preferably 4 or more, and usually 25 or less, preferably 15 or less carbon atoms. Be done. Specific examples include a phenylamino group, a diphenylamino group, a tolylamino group, a pyridylamino group, a thienylamino group and the like.
Examples of the acylamino group include an acylamino group having one or more acyl groups having usually 2 or more carbon atoms and usually 25 or less, preferably 15 or less carbon atoms. Specific examples include an acetylamino group and a benzoylamino group.

Examples of the alkoxy group include an alkoxy group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less carbon atoms. Specific examples include a methoxy group, an ethoxy group, a butoxy group and the like.
Examples of the aryloxy group include an aryloxy group having an aromatic hydrocarbon group or an aromatic heterocyclic group having a carbon number of usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples include a phenyloxy group, a naphthyloxy group, a pyridyloxy group, a thienyloxy group and the like.

Examples of the acyl group include an acyl group having usually 1 or more carbon atoms and usually 25 or less, preferably 15 or less carbon atoms. Specific examples include a formyl group, an acetyl group, a benzoyl group and the like.
Examples of the alkoxycarbonyl group include an alkoxycarbonyl group having usually 2 or more carbon atoms and usually 10 or less, preferably 7 or less carbon atoms. Specific examples include a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the aryloxycarbonyl group include those having an aromatic hydrocarbon group or an aromatic heterocyclic group having a carbon number of usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples include a phenoxycarbonyl group and a pyridyloxycarbonyl group.
Examples of the alkylcarbonyloxy group include an alkylcarbonyloxy group having usually 2 or more carbon atoms and usually 10 or less, preferably 7 or less carbon atoms. Specific examples include an acetoxy group and a trifluoroacetoxy group.

Examples of the alkylthio group include an alkylthio group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less carbon atoms. Specific examples include a methylthio group and an ethylthio group.
Examples of the arylthio group include an arylthio group having a carbon number of usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 14 or less. Specific examples include a phenylthio group, a naphthylthio group, a pyridylthio group and the like.

Specific examples of the alkylsulfonyl group and the arylsulfonyl group include a mesylate group and a tosyl group.
Specific examples of the sulfonyloxy group include a mesyloxy group and a tosyloxy group.
Specific examples of the silyl group include a trimethylsilyl group and a triphenylsilyl group.

As described above, ^{the groups exemplified as R 11} and R ¹² may be further substituted with other substituents as long as it does not contradict the gist of the present invention. The type of the substituent is not particularly limited, and examples thereof include a halogen atom, a cyano group, a thiocyano group, a nitro group, and the like, in addition to the groups exemplified as ^{R 11} and R ^{12, respectively.} Above all, from the viewpoint of not interfering with the heat resistance and electron acceptability of the ionic compound (electron-accepting compound), an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an aromatic hydrocarbon group and an aromatic heterocycle Groups are preferred.

In the formula (5), A ₁ is preferably an element belonging to Group 17 of the periodic table, and from the viewpoint of electron acceptability and availability, it is before the 5th cycle of the periodic table (3rd to 5th cycles). ) Is preferable. That is, an iodine atom as A _1, a bromine atom, either of the chlorine atoms are preferred.
In particular, an electron-accepting, in view of stability of the compound, ionic compound is preferably A ₁ in the formula (5) is a bromine atom or an iodine atom, ion compound is most preferably an iodine atom.

In formula (5), Z ₁ n ₁ − represents a counter anion. The type of counter anion is not particularly limited, and may be a monatomic ion or a complex ion. However, as the size of the counter anion is larger, the negative charge is delocalized, and the positive charge is also delocalized accordingly, so that the electron accepting capacity is increased. Therefore, the complex ion is preferable to the monatomic ion.
n ₁ is any positive integer corresponding to the ionic value of the counter anion Z ₁ n _{1 −.} The value of n ₁ is not particularly limited, but is preferably 1 or 2, and most preferably 1.

Specific examples of Z ₁ n _1- include hydroxide ion, fluoride ion, chloride ion, bromide ion, iodide ion, cyanide ion, nitrate ion, nitrite ion, sulfate ion, sulfite ion, and perchlorine. Acid ion, perbromate ion, periodate ion, chlorate ion, chlorite ion, hypochlorite ion, phosphate ion, phosphite ion, hypophosphate ion, borate ion, isocyanate ion , Hydrogen sulfide ion, tetrafluoroborate ion, hexafluorophosphate ion, hexachloroantimonate ion; carboxylic acid ion such as acetate ion, trifluoroacetate ion, benzoate ion; methanesulfonic acid, trifluoromethanesulfonic acid ion, etc. Sulfonate ions; alkoxy ions such as methoxy ion and t-butoxy ion can be mentioned. Of these, tetrafluoroboronate ion and hexafluoroboronate ion are preferable.

Further, as the counter anion Z ₁ n ₁ −, the negative charge is delocalized in terms of the stability of the compound, the solubility in the solvent, and the large size, and the positive charge is also delocalized accordingly. Therefore, the complex ion represented by the following formula (6) is particularly preferable because the electron accepting capacity is increased.

(In the formula, E ₁ independently represents an element belonging to Group 13 of the long periodic table, and Ar ^{6 to} Ar ⁹ independently represent 1-3 aromatic hydrocarbon groups or 1-3. Represents an aromatic heterocyclic group.)
As E ₁ , a boron atom, an aluminum atom, and a gallium atom are preferable, and a boron atom is more preferable from the viewpoint of compound stability, easiness of synthesis and purification.
Aromatic hydrocarbon group Ar ⁶ to Ar ^9, the aromatic heterocyclic group, for example, the same as those exemplified above for R ^11, having one free valence, 5- or 6-membered ring A single ring or a 2-4 fused ring of the above can be mentioned. Among them, a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, and an isoquinoline ring having one free valence are preferable from the viewpoint of compound stability and heat resistance. ..

The ^{aromatic hydrocarbon groups and aromatic heterocyclic groups exemplified as Ar 6 to} Ar ⁹ may be further substituted with another substituent as long as it does not contradict the gist of the present invention. The type of the substituent is not particularly limited, and any substituent can be applied, but an electron-withdrawing group is preferable.
To exemplify a preferable electron-withdrawing group as a substituent that Ar ^{6 to} Ar ⁹ may have, a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom; a cyano group; a thiocyano group; a nitro group; a mesyl group. Alkylsulfonyl groups such as; arylsulfonyl groups such as tosyl groups; acyl groups having a carbon number of usually 1 or more, usually 12 or less, preferably 6 or less, such as formyl groups, acetyl groups, benzoyl groups; methoxycarbonyl groups, ethoxycarbonyls, etc. An alkoxycarbonyl group having a group or the like having a carbon number of usually 2 or more, usually 10 or less, preferably 7 or less; a phenoxycarbonyl group, a pyridyloxycarbonyl group or the like having a carbon number of usually 3 or more, preferably 4 or more, usually 25 or less. An aryloxycarbonyl group having an aromatic hydrocarbon group or an aromatic heterocyclic group of 15 or less, preferably an aminocarbonyl group; an aminosulfonyl group; a trifluoromethyl group, a pentafluoroethyl group, etc., which usually have 1 or more carbon atoms. Examples thereof include a haloalkyl group in which a linear, branched or cyclic alkyl group of 10 or less, preferably 6 or less is substituted with a halogen atom such as a fluorine atom or a chlorine atom.

Above all, ^{it is more preferable that at least one group of Ar 6 to} Ar ⁹ has one or two or more groups having a fluorine atom or a chlorine atom as a substituent. In particular, it is most likely that the hydrogen atoms of ^{Ar 6 to} Ar ⁹ are all perfluoroaryl groups substituted with fluorine atoms from the viewpoint of efficiently delocalizing negative charges and having appropriate sublimation properties. preferable. Specific examples of the perfluoroaryl group include a pentafluorophenyl group, a heptafluoro-2-naphthyl group, a tetrafluoro-4-pyridyl group and the like.

The molecular weight of the electron-accepting compound in the present invention is usually 100 to 5000, preferably 300 to 3000.
Within the above range, positive charges and negative charges are sufficiently delocalized, electron acceptability is good, and charge transport is not hindered, which is preferable.
Specific examples of the electron-accepting compound represented by the above formula (5) suitable for the present invention are shown in Table 1 below, but the present invention is not limited thereto.

The composition for an organic electroluminescent device of the present invention may contain one kind of the above-mentioned electron-accepting compound alone, or may contain two or more kinds in any combination and ratio.
When the composition for an organic electroluminescent element of the present invention contains an electron-accepting compound, the content of the electron-accepting compound in the composition for an organic electroluminescent element of the present invention is usually 0.0005% by weight or more, preferably 0. It is .001% by weight or more, usually 20% by weight or less, preferably 10% by weight or less. The ratio of the electron-accepting compound to the polymer of the present invention in the composition for an organic electroluminescent element is usually 0.5% by weight or more, preferably 1% by weight or more, and more preferably 3% by weight or more. It is usually 80% by weight or less, preferably 60% by weight or less, and more preferably 40% by weight or less.

When the content of the electron-accepting compound in the composition for an organic electroluminescent element is at least the above lower limit, the electron acceptor receives electrons from the polymer and the formed organic layer has low resistance, which is preferable. This is preferable because defects are less likely to occur in the formed organic layer and uneven film thickness is less likely to occur.

[Cation radical compound]
The composition for an organic electroluminescent device of the present invention may further contain a cationic radical compound.
As the cation radical compound, an ionic compound composed of a cation radical, which is a chemical species obtained by removing one electron from a hole transporting compound, and a counter anion is preferable. However, when the cation radical is derived from a hole-transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.
Further, the cation radical is preferably a chemical species obtained by removing one electron from the hole transporting compound described later. A chemical species obtained by removing one electron from a preferable compound as a hole transporting compound is preferable from the viewpoints of amorphousness, visible light transmittance, heat resistance, solubility and the like.

Here, the cationic radical compound can be produced by mixing the hole transporting compound described later and the electron accepting compound described above. That is, by mixing the hole transporting compound and the electron accepting compound, electron transfer occurs from the hole transporting compound to the electron accepting compound, and the hole transporting compound is composed of a cationic radical and a counter anion. A cationic ion compound is produced.

When the composition for an organic electroluminescent element of the present invention contains a cation radical compound, the content of the cation radical compound in the composition for an organic electroluminescent element of the present invention is usually 0.0005% by weight or more, preferably 0.001. By weight or more, usually 40% by weight or less, preferably 20% by weight or less. When the content of the cationic radical compound is not less than the lower limit, the resistance of the formed organic layer is lowered, which is preferable, and when it is not more than the upper limit, defects are less likely to occur in the formed organic layer and uneven film thickness is less likely to occur.
In addition to the above components, the composition for an organic electroluminescent device of the present invention contains components contained in the hole injection layer forming composition and the hole transport layer forming composition described later. It may be contained in.

<Organic electroluminescent device>
The organic electroluminescent device of the present invention is an organic electroluminescent device having an anode and a cathode and an organic layer between the anode and the cathode on a substrate, and the organic layer contains the polymer of the present invention. It is characterized by including a layer formed by a wet film forming method using the composition for an organic electroluminescent device of.
In the organic electroluminescent device of the present invention, the layer formed by the wet film forming method is preferably at least one of a hole injection layer and a hole transport layer, and in particular, this organic layer is a hole injection layer and a positive. It is preferable that the hole transport layer and the light emitting layer are provided, and all of the hole injection layer, the hole transport layer and the light emitting layer are formed by a wet film forming method.

In the present invention, the wet film forming method is a film forming method, that is, as a coating method, for example, a spin coating method, a dip coating method, a die coating method, a bar coating method, a blade coating method, a roll coating method, a spray coating method, and a capillary. A method of forming a film by adopting a wet film forming method such as a coating method, an inkjet method, a nozzle printing method, a screen printing method, a gravure printing method, or a flexographic printing method, and drying the coating film. Among these film forming methods, a spin coating method, a spray coating method, an inkjet method, a nozzle printing method and the like are preferable.

As an example of the structure of the organic electroluminescent device of the present invention, FIG. 1 shows a schematic view (cross section) of a structural example of the organic electroluminescent device 10. In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light emitting layer, 6 is a hole blocking layer, 7 is an electron transport layer, and 8 is an electron injection layer. 9 represents each cathode.
Hereinafter, an example of an embodiment such as a layer structure of the organic electroluminescent device of the present invention and a general method for forming the same will be described with reference to FIG.

[substrate]
The substrate 1 serves as a support for an organic electroluminescent element, and usually a quartz or glass plate, a metal plate, a metal foil, a plastic film, a sheet, or the like is used. Of these, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. The substrate is preferably made of a material having a high gas barrier property because the organic electroluminescent element is unlikely to be deteriorated by the outside air. Therefore, particularly when a material having a low gas barrier property such as a synthetic resin substrate is used, it is preferable to provide a dense silicon oxide film or the like on at least one surface of the substrate to improve the gas barrier property.

[anode]
The anode 2 has a function of injecting holes into the layer on the light emitting layer 5 side.
The anode 2 is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum; a metal oxide such as an oxide of indium and / or tin; a metal halide such as copper iodide; carbon black and poly (3). -Methylthiophene), polypyrrole, polyaniline and other conductive polymers.

The anode 2 is usually formed by a dry method such as a sputtering method or a vacuum vapor deposition method. When forming an anode using metal fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc., use an appropriate binder resin solution. It can also be formed by dispersing and applying it on a substrate. Further, in the case of a conductive polymer, a thin film can be formed directly on the substrate by electrolytic polymerization, or an anode can be formed by applying the conductive polymer on the substrate (Appl. Phys. Lett., 60). Vol. 2711, 1992).

The anode 2 usually has a single-layer structure, but may have a laminated structure as appropriate. When the anode 2 has a laminated structure, different conductive materials may be laminated on the first-layer anode.
The thickness of the anode 2 may be determined according to the required transparency, material, and the like. When particularly high transparency is required, a thickness having a visible light transmittance of 60% or more is preferable, and a thickness having a visible light transmittance of 80% or more is more preferable. The thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, when transparency is not required, the thickness of the anode 2 may be arbitrarily set according to the required strength and the like. In this case, the anode 2 may have the same thickness as the substrate.
When another layer is formed on the surface of the anode 2, impurities on the anode 2 are removed by treating with ultraviolet rays / ozone, oxygen plasma, argon plasma, etc. before the film formation, and the ionization potential thereof is formed. It is preferable to improve the hole injection property.

[Hole injection layer]
The layer having a function of transporting holes from the anode 2 side to the light emitting layer 5 side is usually called a hole injection transport layer or a hole transport layer. When there are two or more layers having a function of transporting holes from the anode 2 side to the light emitting layer 5, the layer closer to the anode side may be referred to as the hole injection layer 3. The hole injection layer 3 is preferably formed in terms of enhancing the function of transporting holes from the anode 2 to the light emitting layer 5. When forming the hole injection layer 3, the hole injection layer 3 is usually formed on the anode 2.

The film thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.
The hole injection layer may be formed by either a vacuum vapor deposition method or a wet film deposition method. In terms of excellent film forming property, it is preferably formed by a wet film forming method.
The hole injection layer 3 preferably contains a hole transporting compound, and more preferably contains a hole transporting compound and an electron accepting compound. Further, it is preferable to contain a cationic radical compound in the hole injection layer, and it is particularly preferable to contain a cationic radical compound and a hole transporting compound.
A general method for forming the hole injection layer will be described below. In the organic electroluminescent device of the present invention, the hole injection layer is a wet film forming method using the composition for the organic electroluminescent device of the present invention. Is preferably formed by.

[Hole transporting compound]
The composition for forming a hole injection layer usually contains a hole transporting compound that becomes the hole injection layer 3. Further, in the case of the wet film forming method, a solvent is usually further contained. It is preferable that the composition for forming a hole injection layer has high hole transportability and can efficiently transport the injected holes. Therefore, it is preferable that the hole mobility is high and impurities that serve as traps are unlikely to be generated during production or use. Further, it is preferable that the stability is excellent, the ionization potential is small, and the transparency to visible light is high. In particular, when the hole injection layer is in contact with the light emitting layer, those that do not quench the light emitted from the light emitting layer or those that form an exciplex with the light emitting layer and do not reduce the luminous efficiency are preferable.

As the hole transporting compound, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferable from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of hole-transporting compounds include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which a tertiary amine is linked with a fluorene group, and hydrazone. Examples thereof include system compounds, silazane compounds, and quinacridone compounds.

Among the above-mentioned exemplified compounds, aromatic amine compounds are preferable, and aromatic tertiary amine compounds are particularly preferable, from the viewpoint of amorphousness and visible light transmission. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and also includes a compound having a group derived from the aromatic tertiary amine.
The type of the aromatic tertiary amine compound is not particularly limited, but a polymer compound having a weight average molecular weight of 1000 or more and 1000,000 or less (polymerized compound in which repeating units are continuous) is easy to obtain uniform light emission due to the surface smoothing effect. ) Is preferably used. Preferred examples of the aromatic tertiary amine polymer compound include, in addition to the polymer of the present invention, a polymer compound having a repeating unit represented by the following formula (7).

(In the above formula (7), Ar ^b1 and Ar ^b2 are each independently an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Represents Ar ^b3 ~ A
r ^b5 independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Z ^b represents a linking group selected from the following linking group group. Further, of Ar ^{b1 to} Ar ^b5 , two groups bonded to the same N atom may be bonded to each other to form a ring. )

(In each of the above formulas, Ar ^{b6 to} Ar ^b16 are each independently an aromatic hydrocarbon which may have a substituent or a monovalent derived from an aromatic heterocycle which may have a substituent. Or represents a divalent group. R ^b1 and R ^b2 each independently represent a hydrogen atom or an arbitrary substituent.)
As Ar ^{b1 to} Ar ^b16 , a monovalent or divalent group derived from any aromatic hydrocarbon or aromatic heterocycle can be applied. Each of these groups may be the same or different from each other. Further, these groups may further have an arbitrary substituent.

Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the general formula (7) include the compounds described in Pamphlet No. 2005/089024.
Since the hole injecting layer 3 can improve the conductivity of the hole injecting layer by oxidizing the hole transporting compound, the hole injecting layer 3 contains the above-mentioned electron accepting compound and the above-mentioned cationic radical compound. Is preferable.

Cationic radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, Vol. 12, p. 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, Vol. 94, p. 7716) It is also produced by oxidative polymerization (dehydrogenation polymerization).
The oxidative polymerization referred to here is to chemically or electrochemically oxidize a monomer in an acidic solution using peroxodisulfate or the like. In the case of this oxidative polymerization (dehydropolymerization), a cation radical obtained by removing one electron from a repeating unit of a polymer, which is polymerized by oxidizing a monomer and has an anion derived from an acidic solution as a counter anion, is generated. Generate.

[Formation of hole injection layer by wet film formation method]
When the hole injection layer 3 is formed by the wet film formation method, the material to be the hole injection layer is usually mixed with a soluble solvent (solvent for the hole injection layer) to form a composition for film formation (holes). A composition for forming an injection layer) is prepared, and this composition for forming a hole injection layer is applied onto a layer (usually an anode) corresponding to the lower layer of the hole injection layer to form a film, and then dried. Form.

The film thickness of the hole injection layer is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.
The content of the electron-accepting compound in the hole injection layer with respect to the hole-transporting compound is usually 0.1 mol% or more, preferably 1 mol% or more. However, it is usually 100 mol% or less, preferably 40 mol% or less.

[Other constituent materials]
As the material of the hole injection layer, other components may be further contained in addition to the above-mentioned hole transporting compound and electron accepting compound as long as the effects of the present invention are not significantly impaired. Examples of other components include various light-emitting materials, electron-transporting compounds, binder resins, and coatability improvers. As the other components, only one type may be used, or two or more types may be used in any combination and ratio.

[solvent]
It is preferable that at least one of the solvents of the composition for forming the hole injection layer used in the wet film forming method is a compound capable of dissolving the constituent material of the hole injection layer described above. The boiling point of this solvent is usually 110 ° C. or higher, preferably 140 ° C. or higher, particularly 200 ° C. or higher, usually 400 ° C. or lower, and particularly preferably 300 ° C. or lower. If the boiling point of the solvent is too low, the drying rate may be too fast and the film quality may deteriorate. Further, if the boiling point of the solvent is too high, it is necessary to raise the temperature of the drying step, which may adversely affect other layers and substrates.

Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, amide solvents and the like.
Examples of the ether-based solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and anisole. , Fenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, aromatic ethers such as 2,4-dimethylanisole, and the like.

Examples of the ester-based solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.
Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-iropropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, methylnaphthalene and the like. Can be mentioned.

Examples of the amide-based solvent include N, N-dimethylformamide, N, N-dimethylacetamide, and the like.
In addition, dimethyl sulfoxide, etc. can also be used.
Only one of these solvents may be used, or two or more of these solvents may be used in any combination and ratio.

[Film film method]
After preparing the composition for forming a hole injection layer, this composition is applied onto a layer (usually an anode) corresponding to the lower layer of the hole injection layer by wet film formation, and dried to form a hole injection layer. To form.
The temperature in the film forming step is preferably 10 ° C. or higher, preferably 50 ° C. or lower, in order to prevent the film from being damaged due to the formation of crystals in the composition.

The relative humidity in the film forming step is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.01 ppm or more and usually 80% or less.
After coating, the film of the composition for forming a hole injection layer is usually dried by heating or the like. As a method of drying, a heating step is usually performed. Examples of heating means used in the heating step include clean ovens, hot plates, infrared rays, halogen heaters, microwave irradiation and the like. Above all, a clean oven and a hot plate are preferable in order to evenly apply heat to the entire film.

The heating temperature in the heating step is preferably a temperature equal to or higher than the boiling point of the solvent used in the composition for forming a hole injection layer, as long as the effects of the present invention are not significantly impaired. Further, in the case of a mixed solvent containing two or more kinds of solvents used in the composition for forming a hole injection layer, it is preferable that at least one kind is heated at a temperature equal to or higher than the boiling point of the solvent. Considering the boiling point elevation of the solvent, in the heating step, it is preferable to heat at 120 ° C. or higher, preferably 410 ° C. or lower.

In the heating step, the heating temperature is preferably equal to or higher than the boiling point of the solvent of the composition for forming a hole injection layer. The heating time is not limited as long as the coating film is not sufficiently crosslinked, but is preferably 10 seconds or more, usually 180 minutes or less. If the heating time is too long, the components of other layers tend to diffuse, and if it is too short, the hole injection layer tends to become inhomogeneous. Heating may be performed in two steps.

<Formation of hole injection layer by vacuum deposition method>
When forming a hole injection layer by vacuum deposition, one or more of the constituent materials of the hole injection layer (the above-mentioned hole transporting compound, electron accepting compound, etc.) are installed in a vacuum vessel. Put it in a crucible (if you use two or more materials, put it in each crucible), ^{exhaust the inside of the vacuum vessel to about 10-4} Pa with an appropriate vacuum pump, and then heat the crucible (two or more kinds). When using materials, heat each crucible), control the amount of evaporation to evaporate (when using two or more materials, control the amount of evaporation independently to evaporate), and place them facing the crucible. A hole injection layer is formed on the anode of the crucible substrate. When two or more kinds of materials are used, a mixture thereof can be put in a crucible and heated and evaporated to form a hole injection layer.

The degree of vacuum during vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 × 10 ^-6 Torr (0.13 × 10 ^-4 Pa) or more, and usually 9.0 × 10 ^-6 Torr. It is (12.0 × 10 ^-4 Pa) or less. The vapor deposition rate is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 Å / sec or more and usually 5.0 Å / sec or less. The film formation temperature at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 ° C. or higher, preferably 50 ° C. or lower.
The film thickness of the hole injection layer is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[Hole transport layer]
The hole transport layer can be formed on the hole injection layer when there is a hole injection layer, and on the anode when there is no hole injection layer. Further, the organic electroluminescent device of the present invention may have a configuration in which the hole transport layer is omitted.
As the material for forming the hole transport layer, it is preferable that the material has a high hole transport capacity and can efficiently transport the injected holes. Therefore, it is preferable that the ionization potential is small, the transparency is high with respect to visible light, the hole mobility is large, the stability is excellent, and impurities that become traps are less likely to be generated during production or use. Further, in many cases, since it is in contact with the light emitting layer, it is preferable not to quench the light emitted from the light emitting layer or form an exciplex with the light emitting layer to reduce the efficiency.

From the above points, the hole transporting compound is particularly preferably the arylamine polymer of the present invention. When a compound other than the arylamine polymer of the present invention is used as the hole transporting compound, a material conventionally used as a constituent material of the hole transporting layer can be used. Examples of conventionally used materials include those exemplified as the hole transporting compound used in the hole injection layer described above. Further, two or more fused aromatic rings containing two or more tertiary amines represented by 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl are replaced with nitrogen atoms. Aromatic amine compounds having a starburst structure (J. Lumin. , 72-74, pp. 985, 1997), Aromatic amine compounds consisting of triphenylamine tetramers (Chem. Commun., pp. 2175, 1996), 2,2', 7,7'-tetrakis. -(Diphenylamino) -9,9'-Spirobifluorene and other spiro compounds (Synt)
h. Metals, Vol. 91, p. 209, 1997), carbazole derivatives such as 4,4'-N, N'-dicarbazole biphenyl and the like. In addition, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Laid-Open No. 7-53953), polyarylene ether sulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, p. 33, 1996) and the like can be used. Can be mentioned.

When the hole transport layer is formed by wet film formation, the composition for forming the hole transport layer is prepared in the same manner as in the formation of the hole injection layer, applied, and then heat-dried.
The composition for forming a hole transport layer contains a solvent in addition to the above-mentioned hole transport compound. The solvent used is the same as that used in the composition for forming the hole injection layer. Further, the coating conditions, the heating and drying conditions, and the like are the same as in the case of forming the hole injection layer.

Also when the hole transport layer is formed by vacuum deposition, the film forming conditions and the like are the same as in the case of forming the hole injection layer.
In addition to the hole transporting compound, the hole transporting layer may contain various light emitting materials, an electron transporting compound, a binder resin, a coating property improving agent, and the like.
The hole transport layer may also be a layer formed by cross-linking a cross-linking compound. The crosslinkable compound is a compound having a crosslinkable group, and forms a network polymer compound by crosslinking.

Examples of this crosslinkable group include cyclic ether groups such as oxetane groups and epoxy groups; groups containing unsaturated double bonds such as vinyl groups, trifluorovinyl groups, styryl groups, acrylic groups, methacryloyl groups and cinnamoyl groups. Examples include groups derived from the benzocyclobutene ring.
The crosslinkable compound may be a monomer, an oligomer, or a polymer. The crosslinkable compound may have only one kind, or may have two or more kinds in any combination and ratio.

As the crosslinkable compound, it is preferable to use a hole transporting compound having a crosslinkable group. Examples of hole-transporting compounds include nitrogen-containing aromatic compound derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives, phthalocyanine derivatives, and porphyrin derivatives; triphenylamine derivatives. Cyrol derivatives; oligothiophene derivatives, condensed polycyclic aromatic derivatives, metal complexes and the like. Among them, nitrogen-containing aromatic derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives and carbazole derivatives; triphenylamine derivatives, silol derivatives, condensed polycyclic aromatic derivatives, metal complexes and the like. Preferred, especially triphenylamine derivatives are more preferred.

In order to crosslink a crosslinkable compound to form a hole transport layer, usually, a composition for forming a hole transport layer in which the crosslinkable compound is dissolved or dispersed in a solvent is prepared, and the composition is applied by wet film formation to crosslink. Let me.
The composition for forming a hole transport layer may contain an additive that promotes the cross-linking reaction in addition to the cross-linking compound. Examples of additives that promote the cross-linking reaction include polymerization initiators and polymerization accelerators such as alkylphenone compounds, acylphosphine oxide compounds, metallocene compounds, oxime ester compounds, azo compounds, and onium salts; condensed polycyclic hydrocarbons, Photosensitizers such as porphyrin compounds and diarylketone compounds; and the like.

Further, a coating property improving agent such as a leveling agent and an antifoaming agent; an electron-accepting compound; a binder resin; and the like may be contained.
The composition for forming a hole transport layer contains a crosslinkable compound of usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, usually 50% by weight or less, preferably 20% by weight. It is contained in an amount of 10% by weight or less, more preferably 10% by weight or less.

A composition for forming a hole transport layer containing a crosslinkable compound at such a concentration is formed on a lower layer (usually a hole injection layer), and then the crosslinkable compound is formed by heating and / or irradiation with active energy such as light. Crosslink to a network polymer compound.
The conditions such as temperature and humidity at the time of coating and the heating conditions after coating are the same as the methods described in the above-mentioned <organic electroluminescent device> and [film formation method]. The same applies to the preferred embodiment.
The film thickness of the hole transport layer is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[Light emitting layer]
The light emitting layer has a hole transport layer on the hole transport layer when there is a hole transport layer, and a hole transport layer on the hole injection layer when there is no hole transport layer and there is a hole injection layer. If there is no hole injection layer, it is formed on the anode.
The light emitting layer may be a layer independent of the hole injection layer and the hole transport layer described above, and the hole blocking layer and the electron transport layer described later, but the holes do not form an independent light emitting layer. Other organic layers such as a transport layer and an electron transport layer may play the role of a light emitting layer.
The light emitting layer is formed between the electrodes to which an electric field is applied, with holes injected directly from the anode or through a hole injection layer or a hole transport layer, and directly from the cathode, or a cathode buffer layer or an electron transport layer. It is a layer that is excited by recombination with electrons injected through a hole blocking layer or the like and becomes a main light emitting source.

The light emitting layer can be formed by any method as long as the effect of the present invention is not significantly impaired, and is formed on the anode by, for example, a wet film forming method or a vacuum vapor deposition method. However, when manufacturing a light emitting device having a large area, the wet film forming method is preferable. The wet film deposition method and the vacuum vapor deposition method can be performed by using the same method as the hole injection layer.
The light emitting layer contains at least a material having a light emitting property (light emitting material), and preferably a material having a hole transporting property (hole transporting material) or a material having an electron transporting property (electrons). Transport material) and. Further, the light emitting layer may contain other components as long as the gist of the present invention is not deviated. As these materials, it is preferable to use low molecular weight materials from the viewpoint of forming a light emitting layer by a wet film forming method as described later.

Any known material can be applied as the light emitting material. For example, it may be a fluorescent material or a phosphorescent material, but from the viewpoint of internal quantum efficiency, it is preferably a phosphorescent material.
For the purpose of improving the solubility in a solvent, it is also important to reduce the molecular symmetry and rigidity of the light emitting material, or to introduce a lipophilic substituent such as an alkyl group.

Hereinafter, examples of fluorescent dyes among light emitting materials will be given, but the fluorescent dyes are not limited to the following examples.
Examples of the fluorescent light emitting material (blue fluorescent dye) that gives blue light emission include naphthalene, chrysene, perylene, pyrene, anthracene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof.

The gives the green light-emitting fluorescent dye (green fluorescent dye), for example, quinacridone derivatives, coumarin _derivatives, aluminum complexes such as _{Al (C 9 H 6 NO)} 3 and the like.
Examples of the fluorescent light emitting material (yellow fluorescent dye) that gives yellow light emission include rubrene, a perimidone derivative, and the like.
Examples of the fluorescent light emitting material (red fluorescent dye) that gives red light emission include DCM (4- (dicyanomethyrene) -2-methyl-6- (p-dimethylaminostylyl) -4H-pyran) -based compounds, benzopyran derivatives, rhodamine derivatives, and the like. Examples thereof include benzothioxanthene derivatives and azabenzothioxanthene.

Specific examples of the phosphorescent material include tris (2-phenylpyridine) iridium, tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, bis (2-phenylpyridine) platinum, and tris (2-phenylpyridine). Examples thereof include osmium (phenylpyridine), tris (2-phenylpyridine) renium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, and octaphenyl palladium porphyrin.

Polymer-based luminescent materials include poly (9,9-dioctylfluorene-2,7-diyl) and poly [(9,9-dioctylfluorene-2,7-diyl) -co- (4,4'-). (N
-(4-sec-Butylphenyl)) diphenylamine)], poly [(9,9-dioctylfluorene-2,7-diyl) -co- (1,4-benzo-2 {2,1'-3}-)- Examples thereof include polyfluorene-based materials such as triazole)] and polyphenylene vinylene-based materials such as poly [2-methoxy-5- (2-hepylhexyloxy) -1,4-phenylene vinylene].

Further, the arylamine polymer of the present invention can also be used as a light emitting material.
The molecular weight of the compound used as the luminescent material is arbitrary as long as the effects of the present invention are not significantly impaired, but is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more. The range is preferably 200 or more, more preferably 300 or more, still more preferably 400 or more. If the molecular weight of the luminescent material is too small, the heat resistance will be significantly reduced, gas will be generated, the film quality will be deteriorated when the film is formed, or the morphology of the organic electroluminescent device will change due to migration. It may come. On the other hand, if the molecular weight of the luminescent material is too large, it tends to be difficult to purify the organic compound, or it tends to take time to dissolve it in a solvent.

As the above-mentioned luminescent material, only one of them may be used, or two or more of them may be used in any combination and ratio.
The proportion of the light emitting material in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.05% by weight or more, preferably 35% by weight or less. If the amount of light emitting material is too small, uneven light emission may occur, and if the amount of light emitting material is too large, the current efficiency may decrease. When two or more kinds of light emitting materials are used in combination, the total content of these materials should be included in the above range.

Examples of low-molecular-weight hole-transporting materials include various compounds exemplified as the hole-transporting materials for the hole-transporting layer described above, as well as 4,4'-bis [N- (1-naphthyl) -N-. Aromatic diamine containing two or more tertiary amines represented by [phenylamino] biphenyl and having two or more fused aromatic rings replaced with nitrogen atoms (Japanese Patent Laid-Open No. 5-234681), 4, 4', 4 ”-Aromatic amine compounds having a starburst structure such as tris (1-naphthylphenylamino) triphenylamine (Journal of Luminescence, 1997, Vol.72-74, pp.985), quaternary amount of triphenylamine Aromatic amine compound consisting of body (Chemical Communications, 1996)
Year, pp.2175), 2,2', 7,7'-tetrakis- (diphenylamino) -9,9'-spirobifluorene and other spiro compounds (Synthetic Metals, 1997, Vol.91, pp.209) )
And so on.

Examples of low molecular weight electron transporting materials include 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND) and 2,5-bis (6'-(2',). 2 "-bipyridyl)) -1,1-dimethyl-3,4-diphenylsilol (PyPySPyPy), bathocuproine (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) , Bathocuproine), 2- (4-biphenylyl) -5- (p-talshalbutylphenyl) -1,3,4-oxadiazole (tBu-PBD) and 4,4'-bis (9-carbazole) -Biphenyl (CBP), 9,10-di- (2-naphthyl) anthracene (ADN) and the like.

These hole transporting materials and electron transporting materials are preferably used as host materials in the light emitting layer. Specific examples of the host material include those described in JP-A-2007-067383, JP-A-2007-88433, and JP-A-2007-11093, and the same applies to preferred examples thereof.
Examples of the method for forming the light emitting layer include a wet film deposition method and a vacuum vapor deposition method. Furthermore, the wet film formation method is preferable from the viewpoint that the effect of cross-linking the hole transport layer by the organic compound of the present invention can be enjoyed. When forming a light emitting layer by a wet film forming method, the above-mentioned material is dissolved in an appropriate solvent to prepare a coating solution, which is coated and formed on the hole transport layer after formation, and dried. It is formed by removing the solvent. The method for forming the hole transport layer is the same as the method for forming the hole transport layer.
The film thickness of the light emitting layer is usually in the range of 3 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[Hole blocking layer]
A hole blocking layer 6 may be provided between the light emitting layer 5 and the electron injection layer 8 described later. The hole blocking layer 6 is a layer laminated on the light emitting layer 5 so as to be in contact with the interface of the light emitting layer 5 on the cathode 9 side.
The hole blocking layer 6 has a role of blocking holes moving from the anode 2 from reaching the cathode 9 and a role of efficiently transporting electrons injected from the cathode 9 toward the light emitting layer 5. Has.
The physical properties required for the material constituting the hole blocking layer 6 are high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and an excited triplet level (T1). Is high. Examples of the material of the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanorat) aluminum and the like. Mixed ligand complexes, bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolilato) aluminum dinuclear metal complexes and other metal complexes, distyrylbiphenyl derivatives and the like Triazole derivatives such as styryl compounds (Japanese Patent Laid-Open No. 11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (Japanese Patent Laid-Open No. 7) 4-1759), phenanthroline derivatives such as bathocuproine (Japanese Patent Laid-Open No. 10-79297), and the like can be mentioned. Further, a compound having at least one pyridine ring in which the 2, 4 and 6 positions are substituted as described in International Publication No. 2005-022962 is also preferable as a material for the hole blocking layer 6.

As the material of the hole blocking layer 6, only one kind may be used, or two or more kinds may be used in any combination and ratio.
There is no limitation on the method of forming the hole blocking layer 6. Therefore, it can be formed by a wet film forming method, a thin film deposition method, or another method.
The film thickness of the hole blocking layer 6 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[Electron transport layer]
The electron transport layer is provided between the light emitting layer and the electron injection layer for the purpose of further improving the current efficiency of the device.
The electron transport layer is formed of a compound capable of efficiently transporting electrons injected from the cathode between electrodes to which an electric field is applied in the direction of the light emitting layer. The electron-transporting compound used in the electron-transporting layer is a compound having high electron-injection efficiency from the cathode or the electron-injecting layer and having high electron mobility and capable of efficiently transporting the injected electrons. It is necessary.

Examples of the material satisfying such conditions include a metal complex such as an aluminum complex of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), a metal complex of 10-hydroxybenzo [h] quinoline, an oxadiazole derivative, and a di. Styrylbiphenyl derivative, silol derivative, 3- or 5-hydroxyflavon metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxalin compound (Japanese Patent Laid-Open No. 5,645,948) 6-207169), phenanthroline derivative (Japanese Patent Laid-Open No. 5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinonediimine, n-type hydride amorphous silicon carbide, n Examples thereof include type zinc sulfide and type n-type zinc selenium.
The lower limit of the film thickness of the electron transport layer is usually about 1 nm, preferably about 5 nm, and the upper limit is usually about 300 nm, preferably about 100 nm.
The electron transport layer is formed by laminating on the hole blocking layer by a wet film deposition method or a vacuum vapor deposition method in the same manner as described above. Usually, the vacuum deposition method is used.

[Electron injection layer]
The electron injection layer plays a role of efficiently injecting electrons injected from the cathode into the electron transport layer or the light emitting layer.
In order to efficiently perform electron injection, the material forming the electron injection layer is preferably a metal having a low work function. As an example, alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like are used. The film thickness is usually preferably 0.1 nm or more and 5 nm or less.

Further, an organic electron transport material typified by a nitrogen-containing heterocyclic compound such as basophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline, which will be described later, is doped with an alkali metal such as sodium, potassium, cesium, lithium and rubidium. (Described in JP-A No. 10-270171, JP-A-2002-100478, JP-A-2002-1000482, etc.), it is possible to improve electron injection and transportability and achieve both excellent film quality. Therefore, it is preferable. In this case, the film thickness is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer is formed by laminating on the light emitting layer or the hole blocking layer above it by a wet film forming method or a vacuum vapor deposition method.
The details of the wet film formation method are the same as those of the hole injection layer and the light emitting layer.
On the other hand, in the case of the vacuum vapor deposition method, the vapor deposition source is placed in a crucible or metal boat installed in the vacuum vessel, and the inside of the vacuum vessel is ^{exhausted to about 10 -4} Pa with an appropriate vacuum pump, and then the crucible or metal is used. The boat is heated and evaporated to form an electron injection layer on a light emitting layer, a hole blocking layer or an electron transporting layer on a substrate placed facing a crucible or a metal boat.

The vapor deposition of the alkali metal as the electron injection layer is performed using an alkali metal dispenser filled with alkali metal chromate and a reducing agent. By heating this dispenser in a vacuum vessel, the alkali metal chromate is reduced and the alkali metal is evaporated. When co-depositing an organic electron transport material and an alkali metal, put the organic electron transport material in a crucible installed in a vacuum vessel and exhaust the ^{inside of the vacuum vessel to about 10 -4 Pa with an appropriate vacuum pump.} , Each crucible and dispenser is simultaneously heated and evaporated to form an electron injection layer on a substrate placed facing the crucible and dispenser.
At this time, co-deposited uniformly in the film thickness direction of the electron injection layer, but there may be a concentration distribution in the film thickness direction.

[cathode]
The cathode plays a role of injecting electrons into a layer on the light emitting layer side (electron injection layer, light emitting layer, etc.). As the material of the cathode, the material used for the above-mentioned anode can be used, but in order to efficiently inject electrons, a metal having a low work function is preferable, and tin, magnesium, indium, calcium, aluminum, etc. Suitable metals such as silver or alloys thereof are used. Specific examples include low work function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.
The film thickness of the cathode is usually the same as that of the anode.
For the purpose of protecting the cathode made of a low work function metal, it is preferable to further laminate a metal layer having a high work function and stable to the atmosphere on the cathode because the stability of the device is increased. Metals such as aluminum, silver, copper, nickel, chromium, gold and platinum are used for this purpose.

[others]
Although the layered organic electroluminescent device shown in FIG. 1 has been described above as an example, the organic electroluminescent device of the present invention may have another structure as long as the gist of the organic electroluminescent device is not deviated. For example, an arbitrary layer may be provided between the anode and the cathode in addition to the layer described above, or any layer may be omitted as long as the performance is not impaired.

In the present invention, by using the arylamine polymer of the present invention for the hole transport layer, the hole injection layer, the hole transport layer and the light emitting layer can all be laminated and formed by a wet film forming method. This makes it possible to manufacture a large-area display.
The structure opposite to that of FIG. 1, that is, the cathode, the electron injection layer, the light emitting layer, the hole injection layer, and the anode can be laminated in this order on the substrate, and at least one of them is transparent as described above. It is also possible to provide the organic electroluminescent device of the present invention between two high-cathode substrates.

Further, it is also possible to have a structure in which a plurality of layers shown in FIG. 1 are stacked (a structure in which a plurality of light emitting units are stacked). In that case, instead of the interface layer between the stages (between the light emitting units) (two layers when the anode is ITO and the cathode is Al), for example, V ₂ O ₅ or the like is used as the charge generation layer (CGL). The barrier between them is reduced, which is more preferable from the viewpoint of current efficiency and drive voltage.
The present invention can be applied to any of a single element, an element having an array-arranged structure, and a structure in which an anode and a cathode are arranged in an XY matrix.

<Organic EL display device>
The organic EL display device of the present invention uses the above-mentioned organic electroluminescent device of the present invention. The model and structure of the organic EL display device of the present invention are not particularly limited, and can be assembled according to a conventional method using the organic electroluminescent device of the present invention.
For example, the organic EL display device of the present invention can be used by the method described in "Organic EL Display" (Ohmsha, published on August 20, 2004, by Shizushi Tokito, Chihaya Adachi, Hideyuki Murata). Can be formed.

<Organic EL lighting>
The organic EL illumination of the present invention uses the above-mentioned organic electroluminescent device of the present invention. The type and structure of the organic EL illumination of the present invention are not particularly limited, and can be assembled according to a conventional method using the organic electroluminescent device of the present invention.

(Synthesis of monomer)

3,6-Diiodo-9-phenylcarbazole (21.4 g, 43.22 mmol), 3-bromophenylboronic acid (17.53 g, 87.31 mmol), potassium phosphate (36.7 g, 172.88 mmol), and Toluene (200 ml), ethanol (100 ml), and water (86 ml) were placed in a flask, and the inside of the system was sufficiently replaced with nitrogen and heated to 65 ° C. Bis (triphenylphosphine) palladium (II) dichloride (0.31 g, 0.437 mmol) was added, and the mixture was stirred at 70 ° C. for 5 hours. Water was added to the reaction solution, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified from activated clay. The crude product was purified by column chromatography (developing solution: hexane / methylene chloride = 9/1) to obtain Compound 1 (14.3 g, yield 59.0%).

Then, under a nitrogen stream, 250 ml of dimethylsulfonoxide, compound 1 (14.1 g, 25.48 mmol), bis (pinacolato) diboron (16.2 g, 63.71 mmol), potassium acetate (15.0 g,) in a 500 ml flask. 152.88 mmol) was added, and the mixture was stirred at 60 ° C. for 30 minutes. Then 1,1'-bis (diphenylphosphino) ferrocene-
Palladium (II) dichloride-dichloromethane [PdCl ₂ (dppf) CH ₂ Cl ₂ ] (
2.1 g (2.55 mmol) was added, and the reaction was carried out at 85 ° C. for 6 hours. The reaction mixture was filtered under reduced pressure, the filtrate was extracted with toluene, dried over anhydrous magnesium sulfate, and roughly purified with activated clay. Further, the crude product was purified by column chromatography (developing solution: hexane / methylene chloride = 4/1) to obtain Compound 2 (10.2 g, yield 61.8%).

Compound 2 (10.15 g, 15.68 mmol), 1-bromo-4-iodobenzene (9.3 g, 32.92 mmol), potassium phosphate (17.5 g, 82.3 mmol), and toluene (160 ml) were then followed. , Ethanol (80 ml) and water (42 ml) were placed in a flask, and the inside of the system was sufficiently replaced with nitrogen and heated to 65 ° C. Tetrakis (triphenylphosphine) palladium (0.51 g, 0.441 mmol) was added, and the mixture was stirred at 80 ° C. for 8 hours. Water was added to the reaction solution, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified from activated clay. The crude product was purified by column chromatography (developing solution: hexane / methylene chloride = 4/1) to obtain Compound 3 (9.5 g, yield 85.9%).

(Synthesis of Polymer 1)

Compound 3 (3.00 g, 4.25 mmol), Compound 4 (2.97 g, 8.50 mmol), and tert-butoxysodium (3.15 g, 32.78 mmol), toluene (
43 ml) was charged, the inside of the system was sufficiently replaced with nitrogen, and the mixture was heated to 60 ° C. (solution A). [4- (N, N-dimethylamino) phenyl] di-tert-butylphosphine (4- (N, N-dimethylamino) phenyl] in a 5 ml solution of tris (dibenzylideneacetone) dipalladium complex (0.08 g, 0.09 mmol).
Amphos) (0.18 g, 0.70 mmol) was added and heated to 60 ° C. (Solution B). Solution B was added to solution A in a nitrogen stream, and the mixture was heated under reflux for 1.0 hour. After confirming that compounds 3 and 4 had disappeared, compound 3 (1.86 g, 2.64 mmol) was added. After heating under reflux for 1 hour, compound 5 (0.651 g, 0.90 mmol) was added. After heating under reflux for 1 hour, compound 3 (0.27 g, 0.38 mmol) was added. After heating under reflux for 1 hour, 4-bromobiphenyl (0.99 g, 4.25 mmol) was added, and the mixture was heated under reflux for 2 hours. The reaction mixture was allowed to cool, 50 ml of toluene was added, and the mixture was added dropwise to an ethanol / water (500 ml / 90 ml) solution to obtain an end-capped crude polymer.

The end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The polymer collected by filtration was purified by column chromatography to obtain the target polymer 1 (2.4 g). The molecular weight and the like of the obtained polymer 1 were as follows.
Weight average molecular weight (Mw) = 38700
Number average molecular weight (Mn) = 30700
Dispersity (Mw / Mn) = 1.26

<Solubility test>
The synthesized polymer 1 was subjected to a solubility test in toluene at room temperature (25 ° C.). As a result, the solubility of the polymer 1 in toluene at room temperature (25 ° C.) was 5% by weight or more.

(Example 1)
An organic electroluminescent device having the structure shown in FIG. 1 was produced as described below.
A transparent conductive film of indium tin oxide (ITO) deposited on a glass substrate 1 to a thickness of 70 nm (manufactured by Sanyo Vacuum Co., Ltd., sputter-deposited product) is subjected to ordinary photolithography technology and hydrochloric acid etching. The anode 2 was formed by patterning into stripes having a width of 2 mm to obtain an ITO substrate.

The patterned ITO substrate is washed in the order of ultrasonic cleaning with an aqueous surfactant solution, water washing with ultrapure water, ultrasonic cleaning with ultrapure water, and water washing with ultrapure water, dried with compressed air, and finally ultraviolet rays. Ozone cleaning was performed.
A hole injection layer containing the polymer compound represented by the following structural formula (P-1), 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate represented by the structural formula (A1), and ethyl benzoate. The coating liquid for formation was prepared with the following composition. This coating liquid was filtered using a PTFE (polytetrafluoroethylene) membrane filter having a pore size of 0.2 μm to prepare a coating composition. This coating composition was spin-coated on the ITO substrate. Spin coating was performed in the air at a temperature of 23 ° C. and a relative humidity of 60%, and the hole injection layer 3 having a film thickness of 30 nm was formed by cross-linking by heating. The film formation conditions are shown below.

<Coating liquid for forming hole injection layer>
Solvent Ethyl benzoate
Coating liquid concentration P-1: 2.0% by weight
A1: 0.4% by weight
<Condition conditions for hole injection layer>
Spinner speed 2250 rpm
Spinner rotation time 30 seconds
Spin coating atmosphere in the atmosphere
Heating conditions In the air 230 ° C. for 1 hour Subsequently, a composition for a hole transport layer was prepared as a composition for an organic electroluminescent device containing the polymer 1 shown above with the following composition, and spun under the following film thickness conditions. The hole transport layer 4 having a film thickness of 20 nm was formed by applying by coating and cross-linking by heating. The film formation conditions are shown below.

<Composition for organic electroluminescent device>
Solvent cyclohexylbenzene
Solid content concentration 1.5% by weight
<Conditions for forming a hole transport layer>
Spinner speed 1250 rpm
Spinner rotation time 120 seconds
Spin coating atmosphere in nitrogen
Heating conditions 230 ° C. for 1 hour in nitrogen Next, in forming the light emitting layer 5, the following organic compounds (GH-1, GH-2, GH-3 and GD-1) were used to form the following composition. A composition for a light emitting layer was prepared, applied by spin coating under the following film forming conditions, and dried by heating to form a light emitting layer 5 having a film thickness of 40 nm on the hole transport layer 4.

<Composition for light emitting layer>
Solvent cyclohexylbenzene
Coating liquid concentration (GH-1): 0.675% by weight
(GH-2): 0.675% by weight
(GH-3): 1.65% by weight
(GD-1): 0.9% by weight
<Conditions for film formation of light emitting layer>
Spinner speed 1850 rpm
Spinner rotation time 120 seconds
Spin coating atmosphere in nitrogen
Heating conditions 120 ° C., 20 minutes Here, the substrate on which the light emitting layer 5 is formed is transferred into a vacuum deposition apparatus, and is ^{exhausted until the degree of vacuum in the apparatus becomes 1.3 × 10 -4} Pa or less. GH-2 having a film thickness of 5 nm was laminated on the light emitting layer 5 by a vacuum deposition method to form a hole blocking layer 6.

Subsequently, an organic compound (ET-1) having the structure shown below was heated and vapor-deposited on the hole blocking layer 6 to form an electron transport layer 7. The degree of vacuum during vapor deposition ^{was controlled in the range of 1.3 × 10 -4} Pa, the vapor deposition rate was controlled in the range of 1.6 to 1.8 Å / sec, and the film thickness was set to 5 nm.

Here, the substrate on which the electron transport layer 7 has been vapor-deposited is taken out once, installed in another vapor deposition apparatus, and a 2 mm wide striped shadow mask is used as a mask for cathode vapor deposition, which is orthogonal to the ITO stripe of the anode 2. It was brought into close contact with the substrate as described above, and exhausted until the ^{degree of vacuum in the apparatus became 2.3 × 10 -4 Pa or less.}
Next, as the electron injection layer 8, lithium fluoride (LiF) was first formed on the electron transport layer 7 using a molybdenum boat at a vapor deposition rate of 0.1 Å / sec and a film thickness of 0.5 nm. The degree of vacuum at the time of vapor deposition was 2.6 × 10 ^-4 Pa.

Next, aluminum was similarly heated as the cathode 9 by a molybdenum boat, and the vapor deposition rate was controlled in the range of 1.0 to 4.9 Å / sec to form an aluminum layer having a film thickness of 80 nm. The degree of vacuum at the time of vapor deposition was 2.6 × 10 ^-4 Pa. The substrate temperature during the vapor deposition of the above two layers was maintained at room temperature.
Subsequently, in order to prevent the organic electroluminescent device from deteriorating due to moisture in the atmosphere during storage, the sealing treatment was carried out by the method described below.

In the nitrogen glove box, a photocurable resin 30Y-437 (manufactured by ThreeBond Co., Ltd.) is applied to the outer periphery of a glass plate with a size of 23 mm x 23 mm with a width of about 1 mm, and a moisture getter sheet (manufactured by Dynic Co., Ltd.) is applied to the center. ) Was installed. On this, the substrate for which the cathode formation was completed was bonded so that the vapor-deposited surface faced the desiccant sheet. Then, only the region coated with the photocurable resin was irradiated with ultraviolet light to cure the resin.
As described above, an organic electroluminescent device having a light emitting area portion having a size of 2 mm × 2 mm was produced.

(Comparative Example 1)
The organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 1 except that the comparative polymer 1 shown in H1 below was used instead of the polymer 1.

<Evaluation of current-voltage characteristics of organic electroluminescent devices>
The current-voltage characteristics of the organic electroluminescent device obtained in Example 1 and Comparative Example 1 were evaluated.
Table 3 shows the results of evaluating the drive voltage, current efficiency, and drive life.

Regarding the drive voltage, the drive voltage (V) when the organic electroluminescent elements of Example 1 and Comparative Example 1 were ^{made to emit light at 1000 cd / m 2} was measured, and the value obtained by subtracting the drive voltage of Comparative Example 1 is shown in Table 3. It was shown to.
Regarding the current efficiency, the current efficiency (cd / A) when the organic electroluminescent devices of Example 1 and Comparative Example 1 were ^{made to emit light at 1000 cd / m 2} was measured, and the current efficiency of Comparative Example 1 was set to 1.0. Table 3 shows the ratio (relative value) to the current efficiency of Comparative Example 1.

Regarding the drive life, the organic electroluminescent elements of Example 1 and Comparative Example 1 ^{were driven at 15 mA / cm 2} , and the time (h) when the brightness became 95% of the initial value was measured as the drive life, and the comparative example. The drive life of 1 is 1.0, and the ratio (relative value) to the drive life of Comparative Example 1 is shown in Table 3.
As shown in Table 3, it can be seen that the organic electroluminescent device formed by using the polymer of the present invention has a low drive voltage, high current efficiency, and a long drive life.

The present invention relates to various fields in which an organic electroluminescent element is used, for example, a flat panel display (for example, for an OA computer or a wall-mounted television), or a light source that takes advantage of its characteristics as a surface emitter (for example, a light source for a copying machine). , Liquid crystal display, backlight source of instruments), display board, indicator light, etc., can be suitably used.

1 Substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Hole blocking layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 10 Organic electroluminescent device

Claims (11)

A polymer having a repeating unit represented by the following formula (1).

(In the formula, Ar ¹ , Ar ² , and Ar ³ each independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent ^{, and R 1 has a substituent.} Represents an alkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group, which may be used.) The polymer according to claim 1, which has a crosslinkable group. The polymer according to claim 1 or 2, wherein Ar ³ is a 2-fluorenyl group which may have a substituent. The polymer according to claim 2 or 3, wherein the crosslinkable group is a group containing a cyclobutene ring fused to an aromatic ring. The polymer according to any one of claims 1 to 4, wherein the weight average molecular weight (Mw) is 5,000 or more and the dispersity (Mw / Mn) is 3.5 or less. A composition for an organic electroluminescent device, which contains the polymer according to any one of claims 1 to 5. The method for manufacturing an organic electroluminescent device having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, wherein at least one of the organic layers is the organic electroluminescent device according to claim 6. A method for producing an organic electroluminescent device , which comprises forming a composition for a light emitting element by a wet film forming method. The method for manufacturing an organic electroluminescent device according to claim 7, wherein the layer formed by the wet film forming method is at least one of a hole injection layer and a hole transport layer. The organic electroluminescent device includes a hole injection layer, a hole transport layer, and a light emitting layer between an anode and a cathode, and the hole injection layer, the hole transport layer, and the light emitting layer are all formed by a wet film forming method. The method for manufacturing an organic electroluminescent device according to claim 7 or 8. A method for manufacturing an organic EL display device , which comprises the method for manufacturing an organic electroluminescent device according to any one of claims 7 to 9. A method for manufacturing an organic EL lighting , which comprises the method for manufacturing an organic electroluminescent device according to any one of claims 7 to 9.

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