WO2023189861A1

WO2023189861A1 - Composition, organic electroluminescent element, method for producing same, display device, and lighting device

Info

Publication number: WO2023189861A1
Application number: PCT/JP2023/011022
Authority: WO
Inventors: 司長谷川; 延軍李; 一毅岡部; 宏一朗飯田; 英貴五郎丸; 百合香加藤; 麻優子上田
Original assignee: 三菱ケミカル株式会社
Priority date: 2022-03-29
Filing date: 2023-03-20
Publication date: 2023-10-05
Also published as: TW202348783A

Abstract

The present invention addresses the problem of providing a composition that improves the luminous efficacy of an organic electroluminescent element. The present invention pertains to: a composition that contains an arylamine compound represented by a specific formula and an electron-accepting compound represented by a specific formula; and an organic electroluminescent element having, upon a substrate, an anode, a cathode, and an organic layer between the anode and the cathode, wherein the organic layer contains a cross-linking reaction product of an arylamine compound represented by a specific formula and an electron-accepting compound represented by a specific formula.

Description

Composition, organic electroluminescent device and manufacturing method thereof, display device, and lighting device

The present invention relates to a composition, an organic electroluminescent device, a method for manufacturing the same, a display device, and a lighting device.

In recent years, as thin film type electroluminescent elements, organic electroluminescent elements using organic thin films have been developed instead of those using inorganic materials. Organic electroluminescent devices (OLEDs) usually have a charge injection layer, a charge transport layer, an organic light emitting layer, an electron transport layer, etc. between an anode and a cathode, and materials suitable for each layer are being developed. Development is also progressing in the emission colors of red, green, and blue.

Examples of methods for forming an organic layer of an organic electroluminescent device include a vacuum evaporation method and a wet film formation method (coating method). The vacuum evaporation method has the advantage that since it is easy to stack layers, charge injection from the anode and/or cathode can be improved and excitons can be easily confined in the light emitting layer. On the other hand, the wet film formation method does not require a vacuum process and can easily be applied to a large area.By using a coating solution that is a mixture of multiple materials with various functions, it is possible to easily create multiple materials with various functions. It has advantages such as being able to form a layer containing the following materials. Therefore, in recent years, research and development of organic electroluminescent devices using coating methods has been actively conducted.

Patent Document 1 describes an organic electroluminescent device having a polymer containing a crosslinking group and an electron-accepting compound containing a crosslinking group as a charge injection material. Patent Document 2 describes an organic electroluminescent device having a composition containing a fluorene aryldiamine compound containing a crosslinking group and an electron-accepting compound. Patent Document 3 describes an organic electroluminescent device having a composition containing a carbazole arylamine compound containing a crosslinking group and an electron-accepting compound. Patent Document 4 discloses an organic electroluminescent device containing a compound having one or more polymerizable substituents and two or more carbazole groups in the molecule.

International Publication No. 2019/059331 International Publication No. 2019/231257 US Patent Application Publication No. 2021/0151685 Japanese Patent Application Publication No. 2008-244471

Generally, when an organic electron donor and an organic electron acceptor such as arylamines are mixed in an appropriate ratio and the N atoms of the arylamine partially form an ionic complex with the organic electron acceptor, this ionic complex is formed. Materials that form stable ion complexes are attracting attention because the formation of ions reduces the hole injection barrier from the anode. In the materials and techniques disclosed in Patent Documents 1 to 3, an ion complex is formed from an organic electron donor such as an arylamine polymer, an arylamine low-molecular compound, or an arylamine compound such as carbazole, and an organic electron acceptor. , the driving voltage of the organic electroluminescent device is insufficiently reduced. Further, Patent Document 4 discloses a biscarbazole compound containing an oxetane crosslinking group, but an organic electron acceptor that does not contain a crosslinking group is used as a photopolymerization initiator, and the organic electron acceptor is used up to the light emitting layer. The prevention of diffusion was insufficient, and the luminous efficiency and driving life could not be improved.

The present invention has been made in view of the above-mentioned conventional situation, and an object of the present invention is to provide a composition that improves the luminous efficiency of an organic electroluminescent device.

As a result of extensive studies, the present inventors found that by using a hole injection layer and/or a hole transport layer containing a crosslinking reaction product of an arylamine compound having a crosslinking group and an electron accepting compound having a crosslinking group, The inventors have discovered that the above problems can be solved, and have completed the present invention.
In addition, as a result of intensive studies, the present inventors discovered that the planarity of an arylamine compound having a crosslinking group and a polymer having a crosslinking group was broken by introducing a substituent into the aromatic ring of the main chain. We have discovered that the above problems can be solved by using a hole injection layer and/or a hole transport layer containing a crosslinking reaction product with a polymer having a twisted main chain, and have completed the present invention. Ta.

That is, the gist of the present invention is as follows.
[1]
A composition comprising an arylamine compound represented by any of the following formulas (3-1) to (3-4) and an electron-accepting compound represented by the following formula (81).

(In formulas (3-1) to (3-4),
Ar ² and Ar ³ are each independently one of formulas (4-1) to (4-3),
Each of the plurality of R ² is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a2 are each independently 0 or 1,
Each of the plurality of A ² 's independently represents a hydrogen atom or a crosslinking group. )

(In formulas (4-1) to (4-3),
* represents the bonding position,
Each of the plurality of R ¹ is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a1 are each independently 0 or 1,
Each of the plurality of A ¹ 's independently represents a hydrogen atom or a crosslinking group.
However, at least one of the group consisting of all ^A1 is the above-mentioned crosslinking group. )

(In formula (81), 5 R ⁸¹ , 5 R ⁸² , 5 R ⁸³ , and 5 R ⁸⁴ are each independent, and R ⁸¹ to R ⁸⁴ are each independently a hydrogen atom, a heavy Hydrogen atom, halogen atom, aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, fluorine substitution an alkyl group having 1 to 12 carbon atoms, or a crosslinking group.
Ph ¹ , Ph ² , Ph ³ , and Ph ⁴ are symbols indicating respective benzene rings.
X ⁺ represents a counter cation.
However, formula (81) has at least two crosslinking groups. )

[2]
The composition according to [1], further comprising a polymer having an arylamine structure represented by the following formula (50) as a repeating unit and a crosslinking group.

(In formula (50),
Ar ⁵¹ represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected;
Ar ⁵² is at least one selected from the group consisting of a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group. It represents a divalent group in which one group is connected to a plurality of groups directly or via a linking group.
Ar ⁵¹ and Ar ⁵² may form a ring via a single bond or a connecting group.
Ar ⁵¹ and Ar ⁵² may have a substituent. )

[3]
An arylamine compound represented by any of the formulas (3-1) to (3-4), an electron-accepting compound represented by the formula (81), and an arylamine represented by the formula (50) The composition according to [2], wherein the polymer having the structure as a repeating unit each independently has a crosslinking group selected from formulas (X1) to (X17) in the following crosslinking group group T.
<Bridging group group T>

(In formulas (X1) to (X17), Q represents a direct bond or a connecting group.
* represents the bonding position.
R ¹¹⁰ in formula (X3), formula (X4), formula (X5) and formula (X9) represents a hydrogen atom or an alkyl group which may have a substituent.
In formulas (X1) to (X3), the benzene ring and naphthalene ring may have a substituent.
Further, the substituents may be bonded to each other to form a ring.
In formula (X1) and formula (X2), the cyclobutene ring may have a substituent. )

[4]
The composition according to [3], wherein the crosslinking group is any one of the formulas (X1) to (X3).

[5]
The composition according to any one of [2] to [4], wherein the repeating unit represented by the formula (50) is a repeating unit represented by the following formula (54).

(In formula (54),
Ar ⁵¹ represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected;
X is -C(R ²⁰⁷ )(R ²⁰⁸ )-, -N(R ²⁰⁹ )- or -C(R ²¹¹ )(R ²¹² )-C(R ²¹³ )(R ²¹⁴ )-,
R ²⁰¹ , R ²⁰² , R ²²¹ and R ²²² are each independently an alkyl group which may have a substituent,
R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a hydrogen atom, an aralkyl group which may have a substituent, or a substituent is an aromatic hydrocarbon group which may be
a and b are each independently an integer of 0 to 4,
c is an integer from 0 to 3,
d is an integer from 0 to 4,
i and j are each independently an integer of 0 to 3. )

[6]
None of Ar ² , Ar ³ , Ar ⁵¹ , Ar ⁵² , R ¹ , R ² , R ²⁰¹ , R ²⁰² , R ²²¹ , R ²²² , R ²⁰⁷ to R ²⁰⁹ , R ²¹¹ to R ²¹⁴ has a substituent, The composition according to [5].
[7]
The composition according to any one of [1] to [6], further containing a solvent.
[8]
A method for producing an organic electroluminescent device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer being formed using the composition according to [7]. A method for manufacturing an organic electroluminescent device, including a step of forming it by a wet film forming method.
[9]
The method for manufacturing an organic electroluminescent device according to [8], wherein the organic layer is an organic layer between the anode and the light emitting layer.

[10]
An organic electroluminescent element having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer having the following formulas (3-1) to (3-4). An organic electroluminescent device containing a crosslinking reaction product of an arylamine compound represented by any of the above and an electron-accepting compound represented by the following formula (81).

[11]
An organic electroluminescent element having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer having the following formulas (3-1) to (3-4). An organic electroluminescent device comprising a crosslinking reaction product of an arylamine compound represented by any of the above and a polymer having an arylamine structure represented by the following formula (50) as a repeating unit and a crosslinking group. .

[12]
The organic electroluminescent device according to [11], wherein Ar ² , Ar ³ , Ar ⁵¹ , Ar ⁵² , R ¹ , and R ² have no substituent.
[13]
An organic electroluminescent device manufactured by the method for manufacturing an organic electroluminescent device according to [8] or [9].
[14]
A display device comprising the organic electroluminescent element according to any one of [10] to [13].
[15]
A lighting device comprising the organic electroluminescent element according to any one of [10] to [13].

According to the present invention, a composition that improves the luminous efficiency of an organic electroluminescent device is provided.

FIG. 1 is a schematic cross-sectional view showing a structural example of an organic electroluminescent device of the present invention.

Below, embodiments of a composition, an organic electroluminescent device, a method for manufacturing the same, a display device, and a lighting device, which are one embodiment of the present invention, will be described in detail. The following description is of a first embodiment that is an example (representative example) of the embodiments of the present invention, but the present invention is not limited to these contents unless the gist thereof is exceeded.
In the present invention, "may have a substituent" means that it may have one or more substituents.

[Definition]
In the following, when explaining in detail the structures of the arylamine compound, electron-accepting compound, and polymer (charge-transporting polymer compound) according to the present invention, common partial structures are as follows unless otherwise specified. Suppose there is.

<Aromatic hydrocarbon group>
The aromatic hydrocarbon group refers to a monovalent, divalent, or trivalent or more aromatic hydrocarbon ring structure, depending on the bonding state in the structure of the compound to be explained later.
In the structure of the aromatic hydrocarbon ring, the number of carbon atoms is usually not limited, but is preferably 6 or more and 60 or less, and the upper limit of the carbon number is more preferably 48 or less, more preferably The number of carbon atoms is 30 or less. Specifically, 6-membered rings such as benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring, etc. Examples include monocyclic or 2 to 5 condensed ring groups, or structures in which multiple groups selected from these are connected. When a plurality of aromatic hydrocarbon rings are connected, a structure in which 2 to 10 aromatic hydrocarbon rings are connected is usually used, and a structure in which 2 to 5 aromatic hydrocarbon rings are connected is preferable. When a plurality of aromatic hydrocarbon rings are connected, the same structure may be connected, or different structures may be connected.
Preferred aromatic hydrocarbon ring structures include a benzene ring, a biphenyl ring, that is, a structure in which two benzene rings are connected, a terphenyl ring, that is, a structure in which three benzene rings are connected, a quarterphenylene ring, that is, a structure in which four benzene rings are connected, and a naphthalene ring. , is a fluorene ring.

<Aromatic heterocyclic group>
The aromatic heterocyclic group refers to a monovalent, divalent, or trivalent or more aromatic heterocyclic structure depending on the bonding state in the structure of the compound to be explained below.
In the structure of an aromatic heterocycle, the number of carbon atoms is usually not limited, but is preferably 3 or more and 60 or less, and the upper limit of the carbon number is more preferably 48 or less, more preferably The number of carbon atoms is 30 or less. Specifically, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, Thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring , a 5- to 6-membered monocyclic or 2- to 4-fused divalent group such as a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, or Examples include groups in which a plurality of these are connected. When a plurality of aromatic heterocycles are connected, the same structure may be connected, or different structures may be connected. When a plurality of aromatic heterocycles are connected, a structure in which 2 to 10 aromatic heterocycles are connected is usually mentioned, and a structure in which 2 to 5 aromatic heterocycles are connected is preferable.
Preferred aromatic heterocyclic structures are a thiophene ring, a benzothiophene ring, a pyrimidine ring, a triazine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring.

<Substituent>
Hereinafter, in the description of the structure of the high molecular compound and low molecular compound in the present invention, unless otherwise specified, a substituent is any group, but preferably a group selected from the following substituent group Z and a crosslinking group. It is the basis. In addition, in the description of the structure of the high molecular compound and low molecular compound in the present invention, the substituent that may be included is selected from the substituent group Z, or the substituent that may be included is selected from the substituent group Z. When it is written that it is preferable that Also, Ar ² , Ar ³ , R ¹ , R ² , R ⁸¹ to R ⁸⁵ , R ¹¹⁰ , Ar ⁵¹ to Ar ⁵⁶ , Ar ^d18 , Ar ⁶³ to Ar ⁶⁵ , Ar ⁷¹ to Ar ⁷³ , R ²⁰¹ , R ²⁰² , In the description of the structure of R ²⁰⁷ to R ²⁰⁹ , R ²¹¹ to R ²¹⁴ , R ²²¹ , R ²²² , R ³⁰⁴ , R ³⁰⁵ , R ⁵¹⁷ to R ⁵¹⁹ , the substituent that may be present is selected from crosslinking groups, or , when it is written that the substituent that may be present is preferably selected from crosslinking groups, the preferable crosslinking groups are also as described in the crosslinking group below.
When the composition of the present invention described below contains a polymer having an arylamine structure represented by formula (54) described below as a repeating unit, Ar ² , Ar ³ , Ar ⁵¹ , Ar ⁵² , R ¹ , R ² , R ²⁰¹ , R ²⁰² , R ²²¹ , R ²²² , R ²⁰⁷ to R ²⁰⁹ , and R ²¹¹ to R ²¹⁴ preferably have no substituent. Further, in the organic electroluminescent device of the present invention described below, the organic layer contains an arylamine compound represented by any of formulas (3-1) to (3-4) described below, and an arylamine compound represented by formula (50) described below. When a crosslinking reaction product with a polymer having the arylamine structure expressed as a repeating unit and having a crosslinking group is included, Ar ² , Ar ³ , Ar ⁵¹ , Ar ⁵² , R ¹ , and R ² are all It is preferable that it has no substituent.

<Substituent group Z>
Substituent group Z includes an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, This is a group consisting of a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. These substituents may have any linear, branched, or cyclic structure.

More specifically, the substituent group Z includes the following structures.
Straight chain, branched, or cyclic alkyl having 1 or more carbon atoms, preferably 4 or more, 24 or less, preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less Base. Specific examples include 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, and dodecyl group. etc.
A linear, branched, or cyclic alkenyl group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less; specific examples include vinyl groups.
Straight-chain or branched alkynyl group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less; specific examples include ethynyl group.
An alkoxy group having 1 or more and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include methoxy and ethoxy groups.
An aryloxy group or a heteroaryloxy group having 4 or more carbon atoms, preferably 5 or more, and 36 or less, preferably 24 or less. Specific examples include phenoxy, naphthoxy, and pyridyloxy groups.
An alkoxycarbonyl group having 2 or more and 24 or less carbon atoms, preferably 12 or less. Specific examples include methoxycarbonyl group and ethoxycarbonyl group.
A dialkylamino group having 2 or more and 24 or less carbon atoms, preferably 12 or less. Specific examples include dimethylamino group and diethylamino group.
A diarylamino group having 10 or more carbon atoms, preferably 12 or more, and 36 or less, preferably 24 or less. Specific examples include diphenylamino group, ditolylamino group, N-carbazolyl group, and the like.
An arylalkylamino group having 7 or more carbon atoms and 36 or less carbon atoms, preferably 24 or less carbon atoms. A specific example is a phenylmethylamino group.
An acyl group having 2 or more carbon atoms and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include acetyl group and benzoyl group.
Halogen atoms such as fluorine atoms and chlorine atoms. Preferably it is a fluorine atom. ;
A haloalkyl group having 1 or more carbon atoms and 12 or less carbon atoms, preferably 6 or less carbon atoms. Specific examples include trifluoromethyl group and the like.
An alkylthio group having 1 or more carbon atoms, usually 24 or less, preferably 12 or less. Specific examples include methylthio group and ethylthio group.
An arylthio group having 4 or more carbon atoms, preferably 5 or more, and 36 or less, preferably 24 or less. Specific examples include phenylthio group, naphthylthio group, and pyridylthio group.
A silyl group whose carbon number is usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less. Specific examples include trimethylsilyl group and triphenylsilyl group.
A siloxy group having 2 or more carbon atoms, preferably 3 or more carbon atoms, and usually 36 or less, preferably 24 or less. Specific examples include trimethylsiloxy group, triphenylsiloxy group, and the like.
Cyano group.
An aromatic hydrocarbon group having 6 or more carbon atoms and 36 or less carbon atoms, preferably 24 or less carbon atoms. Specific examples include a phenyl group, a naphthyl group, a group in which a plurality of phenyl groups are linked, and the like.
An aromatic heterocyclic group having 3 or more carbon atoms, preferably 4 or more, and 36 or less, preferably 24 or less. Specific examples include thienyl group and pyridyl group.

The above substituent may have a linear, branched, or cyclic structure.
When the above substituents are adjacent, the adjacent substituents may bond to each other to form a ring. Preferred ring sizes are a 4-membered ring, a 5-membered ring, and a 6-membered ring, and specific examples include a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring.

Among the above substituent group Z, preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, more preferably an alkyl group or an aromatic hydrocarbon group, and most preferably an alkyl group or an aromatic hydrocarbon group. has no substituents.

Moreover, each substituent in the above substituent group Z may further have a substituent. Examples of these substituents include the same ones as in the above substituent group Z or a crosslinking group. Preferably, there is no further substituent, or an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms. or phenyl group. From the viewpoint of charge transport properties, it is more preferable to have no additional substituents.
When the substituent that each substituent in the substituent group Z may further include is a crosslinking group, the crosslinking group is preferably a crosslinking group selected from the crosslinking group T. A substituent which preferably further has a crosslinking group is an alkyl group or an aromatic hydrocarbon group.

<Bridging group>
A crosslinking group refers to a group that reacts with another crosslinking group located in the vicinity of the crosslinking group to form a new chemical bond when irradiated with heat and/or active energy rays. In this case, the reactive group may be the same group as the crosslinking group or a different group.

Examples of the crosslinking group include, but are not limited to, a group containing an alkenyl group, a group containing a conjugated diene structure, a group containing an alkynyl group, a group containing an oxirane structure, a group containing an oxetane structure, a group containing an aziridine structure, an azide group, and anhydride group. Examples include a group containing a maleic acid structure, a group containing an alkenyl group bonded to an aromatic ring, and a cyclobutene ring condensed to an aromatic ring. Specific examples of preferable crosslinking groups are preferably represented by any of the following formulas (X1) to (X17) in the group T of crosslinking groups below.

(Q)
When Q is a linking group, the linking group is not particularly limited, but is preferably an alkylene group, a divalent oxygen atom, or a divalent aromatic hydrocarbon group which may have a substituent.
The alkylene group is usually an alkylene group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms.
The divalent aromatic hydrocarbon group usually has 6 or more carbon atoms, and usually has 36 or less carbon atoms, preferably 30 or less, and more preferably 24 or less carbon atoms, and the aromatic hydrocarbon ring has a structure such as benzene. A ring is preferable, and the substituents that it may have can be selected from the above substituent group Z.

The alkyl group represented by R ¹¹⁰ has a linear, branched or cyclic structure, and has 1 or more carbon atoms, preferably 24 or less, more preferably 12 or less, and even more preferably 8 or less.

The benzene ring and naphthalene ring of formulas (X1) to (X3), and the substituent that R ¹¹⁰ of formula (X3), formula (X4), (X5), and (X9) may have preferably include: They are an alkyl group, an aromatic hydrocarbon group, an alkyloxy group, and an aralkyl group.
The alkyl group as a substituent has a linear, branched or cyclic structure, and the number of carbon atoms is preferably 24 or less, more preferably 12 or less, still more preferably 8 or less, and preferably 1 or more.
The number of carbon atoms in the aromatic hydrocarbon group as a substituent is preferably 24 or less, more preferably 18 or less, still more preferably 12 or less, and preferably 6 or more. The aromatic hydrocarbon group may further have the above alkyl group as a substituent.
The number of carbon atoms in the alkyloxy group as a substituent is preferably 24 or less, more preferably 12 or less, even more preferably 8 or less, and preferably 1 or more.
The number of carbon atoms in the aralkyl group as a substituent is preferably 30 or less, more preferably 24 or less, even more preferably 14 or less, and preferably 7 or more. The alkylene group contained in the aralkyl group preferably has a linear or branched structure. The aryl group contained in the aralkyl group may further have the above-mentioned alkyl group as a substituent.
Preferred substituents that the cyclobutene rings of formulas (X1) and (X2) may have are alkyl groups. The alkyl group as the substituent has a linear, branched or cyclic structure, and the number of carbon atoms is preferably 24 or less, more preferably 12 or less, still more preferably 8 or less, and preferably 1 or more.

As the crosslinking group, a crosslinking group represented by either formula (X1) or formula (X2) is preferable because the crosslinking reaction proceeds only with heat, has low polarity, and has little effect on charge transport.

In the crosslinking group represented by formula (X1), the cyclobutene ring is opened by heat, and the ring-opened groups bond together to form a crosslinked structure, as shown in the following formula. Note that in the following, the description of the linking group Q in formulas (X1) to (X3), etc. is omitted.

In the crosslinking group represented by formula (X2), the cyclobutene ring is opened by heat, and the ring-opened groups bond together to form a crosslinked structure, as shown in the following formula.

In the crosslinking group represented by either formula (X1) or formula (X2), the cyclobutene ring is opened by heat, and if a double bond exists in the vicinity of the ring-opened group, a double bond is formed. Reacts to form a crosslinked structure.
An example will be shown below in which a crosslinking group represented by formula (X1) forms a ring-opened group and a crosslinking group represented by formula (X3) having a double bond site forms a crosslinked structure.

In addition to the crosslinking group represented by formula (X3), the group containing a double bond capable of reacting with the crosslinking group represented by either formula (X1) or formula (X2) includes formula (X4) , (X5), (X11), (X14), (X15), (X16), and (X17). When a group containing these double bonds is used as a crosslinking group in an electron-accepting compound, the formula (X1 ) and formula (X2) are preferable because the possibility of forming a crosslinked structure increases.

As the crosslinking group, a radically polymerizable crosslinking group represented by any one of formulas (X3), (X4), and (X5) is preferable because it has low polarity and is unlikely to interfere with charge transport.

As the crosslinking group, a crosslinking group represented by formula (X6) is preferable in terms of improving electron-accepting properties. Note that when the crosslinking group represented by formula (X6) is used, the following crosslinking reaction proceeds.

A crosslinking group represented by either formula (X7) or (X8) is preferred in terms of high reactivity. Note that when the crosslinking group represented by formula (X7) and the crosslinking group represented by formula (X8) are used, the following crosslinking reaction proceeds.

As the crosslinking group, a cationically polymerizable crosslinking group represented by any one of formulas (X9), (X10), and (X11) is preferred in terms of high reactivity.

<Charge transport material>
The charge transport material according to the present invention is a material capable of transporting holes and/or electrons. Both the arylamine compound having a crosslinking group and the charge-transporting polymer compound according to the present invention, which will be described later, are charge-transporting materials. Further, the charge transport material according to the present invention preferably has hole transport properties, and is preferably a material that is oxidized by an electron-accepting compound to form a cation radical. In the present invention, the charge transporting polymer compound is preferably a hole transporting polymer compound, and preferably a polymer containing an arylamine structure as a repeating unit. In this case, charges are usually holes, transporting charges means transporting holes, the charge transport film is a hole transport film, and the charge injection layer is a hole injection layer.

[Composition of the present invention]
The composition of the present invention comprises an arylamine compound represented by any of the following formulas (3-1) to (3-4) (hereinafter sometimes referred to as "arylamine compound of the present invention"), and This is a composition containing an electron-accepting compound represented by the following formula (81) (hereinafter sometimes referred to as "electron-accepting compound of the present invention"). Further, other compositions of the present invention further include a polymer having an arylamine structure represented by the following formula (50) as a repeating unit and a crosslinking group, in addition to the composition of the present application. A composition containing.
Further, still another composition of the present invention includes an arylamine compound represented by any of the following formulas (3-1) to (3-4) and an arylamine structure represented by the following formula (50) repeating. This is a composition containing a polymer having a crosslinking group as a unit.
Here, the polymer represented by the following formula (50) is a polymer containing as a repeating unit an arylamine structure having a twisted structure that inhibits conjugation.
It is preferable that the composition of the present invention contains a polymer represented by the following formula (50) from the viewpoint of extending the service life.

(In formula (81), 5 R ⁸¹ , 5 R ⁸² , 5 R ⁸³ , and 5 R ⁸⁴ are each independent, and R ⁸¹ to R ⁸⁴ are each independently a hydrogen atom, a heavy Hydrogen atom, halogen atom, aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, fluorine substitution an alkyl group having 1 to 12 carbon atoms, or a crosslinking group.
Ph ¹ , Ph ² , Ph ³ , and Ph ⁴ are symbols indicating respective benzene rings.
X ⁺ is a counter cation and preferably has a structure represented by the following formula (83).
However, formula (81) has at least two crosslinking groups. )

(In formula (83), Ar ⁸¹ and Ar ⁸² are each independently an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent.)

(In formula (50),
Ar ⁵¹ represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected;
Ar ⁵² is at least one selected from the group consisting of a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group. It represents a divalent group in which one group is connected to a plurality of groups directly or via a linking group.
Ar ⁵¹ and Ar ⁵² may form a ring via a single bond or a connecting group.
Ar ⁵¹ and Ar ⁵² may have a substituent, and preferably do not have a substituent. )

In the composition of the present invention, an arylamine compound represented by any of the formulas (3-1) to (3-4), an electron-accepting compound represented by the formula (81), and the formula (50 ) It is preferable from the viewpoint of reactivity that the polymer having an arylamine structure as a repeating unit each independently have a crosslinking group selected from formulas (X1) to (X17) in the crosslinking group group T. From the viewpoint of charge transport properties, it is more preferable that the crosslinking group is one of formulas (X1) to (X3).

<Arylamine compound having a crosslinking group>
The arylamine compound according to the present invention is a compound represented by any one of (3-1) to (3-4), and is contained as a charge transport material in the composition for an organic electroluminescent device of the present invention. .

(R ¹ , R ² )
R ¹ and R ² are each independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.
The aromatic hydrocarbon group preferably has 6 to 50 carbon atoms, more preferably 6 to 30 carbon atoms, and still more preferably 6 to 18 carbon atoms. Specifically, the aromatic hydrocarbon group usually has 6 carbon atoms, such as a benzene ring, a naphthalene ring, an anthracene ring, a tetraphenylene ring, a phenanthrene ring, a chrysene ring, a pyrene ring, a benzanthracene ring, or a perylene ring. A monovalent group having an aromatic hydrocarbon structure having a number of usually 30 or less, preferably 18 or less, more preferably 14 or less, or a plurality of structures selected from these structures bonded in a chain or branched manner. Examples include monovalent groups having the following structure. When a plurality of aromatic hydrocarbon rings are connected, a structure in which 2 to 8 aromatic hydrocarbon rings are connected is usually used, and a structure in which 2 to 5 aromatic hydrocarbon rings are connected is preferable. When a plurality of aromatic hydrocarbon rings are connected, the same structure may be connected, or different structures may be connected.

R ¹ and R ² are preferably each independently,
phenyl group,
A divalent group in which multiple benzene rings are bonded in a multi-chain or branched manner,
A divalent group in which one or more benzene rings and at least one naphthalene ring are bonded in a chain or branched manner,
A divalent group in which one or more benzene rings and at least one phenanthrene ring are bonded in a chain or branched manner, or
A divalent group in which one or more benzene rings and at least one tetraphenylene ring are bonded in a chain or branched manner, and more preferably a divalent group in which a plurality of benzene rings are bonded in a chain or branched manner. It is a valent group, and in any case, the order of bonding does not matter.

As mentioned above, the number of bonded benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is usually 2 to 8, preferably 2 to 5. Among these, preferred are bivalent structures in which 1 to 4 benzene rings are connected, divalent structures in which 1 to 4 benzene rings and naphthalene rings are connected, and bivalent structures in which 1 to 4 benzene rings and phenanthrene rings are connected. It is a divalent structure, or a divalent structure in which 1 to 4 benzene rings and tetraphenylene rings are connected.

These aromatic hydrocarbon groups may have a substituent. The substituents that the aromatic hydrocarbon group may have are as described above. When a substituent is selected from substituent group Z, preferred substituents are those of said substituent group Z.

From the viewpoint of solubility and durability of the compound, R ¹ and R ² preferably have at least one partial structure selected from the following formulas (72-1) to (72-6).

In each of the above formulas (72-1) to (72-6), * represents a bond with an adjacent structure or a hydrogen atom, and at least one of the two * represents a bond position with an adjacent structure. In the following description, the definition of * is the same unless otherwise specified.

More preferably, R ¹ and R ² have at least one partial structure selected from formulas (72-1) to (72-4).
More preferably, R ¹ and R ² have at least one partial structure selected from formulas (72-1) to (72-3).
Particularly preferably, R ¹ and R ² have at least one partial structure selected from formulas (72-1) to (72-2).

Preferably, formula (72-2) is the following formula (72-2-2).

More preferred as formula (72-2) is the following formula (72-2-3).

In addition, from the viewpoint of solubility and durability of the compound, as partial structures that R ¹ and R ² preferably have, the partial structure represented by formula (72-1) and the moiety represented by formula (72-2) Examples include partial structures having a structure.

(substituent)
The substituent that R ¹ and R ² may have is preferably a substituent selected from the substituent group Z or a crosslinking group selected from the crosslinking group T. More preferably, the structure has no substituents.

(a1, a2)
a1 and a2 are each independently 0 or 1.

(A ¹ , A ² )
A ¹ and A ² are each independently a hydrogen atom or a crosslinking group.
When A ¹ and A ² are crosslinking groups, a crosslinking group selected from the group T of crosslinking groups is preferable. The number of crosslinking groups possessed by the compounds represented by formulas (3-1) to (3-4) is preferably 1 or more and 5 or less, more preferably 2 or more and 4 or less.

(Specific examples of arylamine compounds)
Preferred specific examples of the arylamine compound are shown below, but the present invention is not limited thereto.

<Reason why the compounds represented by formulas (3-1) to (3-4) are effective>
Since the compounds represented by formulas (3-1) to (3-4) have an arylamine structure at the meta or ortho position of the phenyl group or biphenyl group, they have an arylamine structure at the para position of the phenyl group or biphenyl group. It has a larger band gap and a higher excited triplet energy level than other compounds. Further, since the compounds represented by formulas (3-1) to (3-4) have two or more arylamine structures, they have excellent charge transport ability, particularly hole transport ability. In addition, since the compounds represented by formulas (3-1) to (3-4) have an arylamine structure at the meta or ortho position of the phenyl group or biphenyl group, the arylamine structure is present at the para position of the phenyl group or biphenyl group. It can suppress intermolecular interactions and has higher solubility than compounds with a structure, and can suppress crystal precipitation when made into a coating liquid. In addition, since the compound of the present invention can suppress intermolecular interactions and has high solubility, it has good compatibility with the electron-accepting compound of the present invention, and has a high compatibility with the electron-accepting ionic compound of the present invention. ionic compounds with cation radicals of arylamine compounds are likely to be formed. For the above reasons, it is considered that by using the arylamine compound of the present invention and the composition of the arylamine compound and electron-accepting compound of the present invention, an organic electroluminescent device exhibiting high luminous efficiency can be obtained.

[Electron accepting compound]
In order to improve the hole injection property from the anode to the hole injection layer or the hole transport layer, or to improve the charge transport property within the hole injection layer or the hole transport layer, the hole injection layer or hole Preferably, the charge transport material contained in the transport layer contains a cation radical moiety. In order to convert the charge transport material into cation radicals, an electron-accepting compound is used when forming a hole injection layer or a hole transport layer. As the parent skeleton of the electron-accepting compound, an ionic compound consisting of a tetraarylborate ion, which is an anion with an ionic valence of 1, and a counter cation, which will be described later, is preferred because it has high stability.

(Cation radicalization of charge transport material)
Cation radicalization of the charge transport material is carried out as follows.
When a compound having an amine structure is used as a charge transport material, and a tetraarylborate with diaryliodonium as a countercation is used as an electron-accepting compound, when forming a hole injection layer or a hole transport layer, the following formula The countercation can change from diaryliodonium to ammonium cation.

(For example, Ar, Ar ^1' to Ar ^4' each independently represent an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a substituent) It is a monovalent group in which a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and aromatic heterocyclic groups which may have a substituent are connected.)

Since the ammonium cation produced in the above reaction has a half-occupied orbital (SOMO) that can accept electrons, the tetraarylborate used as the ammonium ion counter cation is an electron-accepting compound.

In the present invention, a compound consisting of a cation and a tetraarylborate ion, which is an anion, of this charge transporting material is referred to as a charge transporting ionic compound. Details will be described later.

As described later, the hole injection layer and/or hole transport layer of the organic electroluminescent device of the present invention is preferably obtained by wet film formation of the composition for forming a charge transport film of the present invention. The composition for forming a charge transport film is preferably a composition obtained through a process of dissolving or dispersing an electron-accepting compound having a tetraarylborate ion structure described below and a charge transport material described below in an organic solvent. . In the charge transport layer of the organic electroluminescent device of the present invention, a charge transporting ionic compound having the tetraarylborate ion structure of the present invention described later as an anion and the cation of the charge transport material of the present invention as a counter cation is used. It is preferable to include.

(Crosslinking reaction product)
When the charge transport material according to the present invention has a crosslinking group, the crosslinking reaction product with the electron-accepting compound having a crosslinking group includes the following crosslinking reaction products.
・A compound in which electron-accepting compounds are crosslinked.
- A compound in which an electron-accepting compound and a charge-transporting material are crosslinked.
- A compound in which an electron-accepting compound and a tetraarylborate ion in the present invention are crosslinked.
- A compound in the present invention in which tetraarylborate ions are crosslinked with each other.
- A compound in which a tetraarylborate ion and a charge transport material are crosslinked in the present invention.

Here, "tetraarylborate ion in the present invention" refers to the case where it exists as an electron-accepting compound which is an ionic compound consisting of a tetraarylborate ion and a counter cation described below, and the tetraarylborate ion described below. and a cation of a charge transporting material.

The two crosslinking groups that undergo a crosslinking reaction may be the same crosslinking group or different crosslinking groups as long as the crosslinking reaction is possible.

[Electron accepting compound]
The electron-accepting compound which is an ionic compound consisting of a tetraarylborate ion and a counter cation is an electron-accepting ionic compound consisting of a counter anion which is a non-coordinating anion and a counter cation represented by the following formula (81). The following formula (81) has the formula (82) described below as an anion as a tetraarylborate ion. Note that the electron-accepting compound according to the present invention may be referred to as an electron-accepting ionic compound.

(In formula (81), 5 R ⁸¹ , 5 R ⁸² , 5 R ⁸³ , and 5 R ⁸⁴ are each independent, and R ⁸¹ to R ⁸⁴ are each independently a hydrogen atom, a heavy Hydrogen atom, halogen atom (I atom, Br atom, Cl atom, F atom), aromatic hydrocarbon group having 6 to 50 carbon atoms that may have a substituent, carbon that may have a substituent It is an aromatic heterocyclic group having 3 to 50 carbon atoms, a fluorine-substituted alkyl group having 1 to 12 carbon atoms, or a crosslinking group.
Ph ¹ , Ph ² , Ph ³ , and Ph ⁴ are symbols indicating respective benzene rings.
X ⁺ represents a counter cation. )

It is preferable that the electron-accepting compound represented by the formula (81) has a crosslinking group, and it is more preferable that the number of crosslinking groups is two or more. The crosslinking group is preferably included in the anion portion of the electron-accepting compound represented by the above formula (81), that is, in the below-described formula (82), which is a tetraarylborate ion.

[Tetraarylborate ion]
The parent skeleton of the electron-accepting compound described above is a boron atom substituted with four aromatic hydrocarbon rings that may have a substituent or an aromatic heterocycle that may have a substituent. An ionic compound consisting of a tetraarylborate ion, which is an anion with an ionic valence of 1, and a counter cation is preferred because it has high stability.

The tetraarylborate ion is an anion form of the above formula (81), which is represented by the following formula (82).

(In formula (82), R ⁸¹ to R ⁸⁴ are the same as R ⁸¹ to R ⁸⁴ in formula (81), respectively.
Ph ¹ to Ph ⁴ are the same as Ph ¹ to Ph ⁴ in formula (81), respectively, and are symbols indicating four benzene rings. )

The aromatic hydrocarbon group used for R ⁸¹ to R ⁸⁴ preferably has 6 to 50 carbon atoms. The aromatic hydrocarbon ring structure is preferably a monocyclic ring, 2 to 6 condensed rings, or a structure in which 2 to 8 rings are connected. Specifically, the aromatic hydrocarbon group includes 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, and a fluorene ring. Examples include a single monovalent group having a ring, a biphenyl structure, a terphenyl structure, or a quaterphenyl structure, and a monovalent group in which 2 to 8 of these are linked.

The aromatic heterocyclic group used for R ⁸¹ to R ⁸⁴ preferably has 3 to 50 carbon atoms. The aromatic heterocyclic structure is preferably a monocyclic ring, 2 to 6 condensed rings, or a structure in which 2 to 8 of these rings are connected. Specifically, the aromatic heterocyclic group includes a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, Pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, A single monovalent group of triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, phenanthridine ring, perimidine ring, quinazoline ring, quinazolinone ring, or azulene ring, and 2 to 8 of these linked together. Examples include monovalent groups. Further, the aromatic heterocyclic group referred to herein may include at least one of these individual structures, and the connected structure may include an aromatic hydrocarbon ring structure. When it contains an aromatic hydrocarbon ring structure, it may have a structure in which 2 to 8 aromatic heterocycles and aromatic hydrocarbon rings are connected in total. Here, as the aromatic hydrocarbon ring, an individual structure of the aromatic hydrocarbon rings used for R ⁸¹ to R ⁸⁴ above can be used.

Among them, monovalent groups such as a benzene ring, naphthalene ring, fluorene ring, pyridine ring, or carbazole ring, or a biphenyl group in which 2 to 5 of these groups are connected are used because of their excellent stability and heat resistance. group is more preferred. Particularly preferred are monovalent benzene ring groups or groups in which 2 to 5 benzene rings are connected, and specific examples include phenyl, biphenyl, and terphenyl groups.

An aromatic hydrocarbon group contained in a monovalent group in which a plurality of structures selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are connected. The number of aromatic heterocyclic groups is 2 or more, preferably 8 or less, more preferably 4 or less, and more preferably 3 or less. However, when the aromatic hydrocarbon group is a biphenyl group, a terphenyl group, or a quaterphenyl group, they are considered to have a structure in which two phenyl groups are connected, a structure in which three phenyl groups are connected, and a structure in which four phenyl groups are connected, respectively.

The substituent that R ⁸¹ to R ⁸⁴ may have is preferably a group selected from the substituent group Z or a crosslinking group.

R ⁸¹ to R ⁸⁴ are preferably a fluorine atom or a fluorine-substituted alkyl group from the viewpoint of increasing the stability of the anion and improving the effect of stabilizing the cation. Further, it is preferable to contain two or more fluorine atoms or fluorine-substituted alkyl groups, more preferably three or more, and most preferably four.

The fluorine-substituted alkyl group used for R ⁸¹ to R ⁸⁴ is preferably a linear or branched alkyl group having 1 to 12 carbon atoms and substituted with a fluorine atom, and more preferably a perfluoroalkyl group. Preferably, a straight chain or branched perfluoroalkyl group having 1 to 5 carbon atoms is more preferred, a straight chain or branched perfluoroalkyl group having 1 to 3 carbon atoms is particularly preferred, and a perfluoromethyl group is most preferred. The reason for this is that the charge injection layer containing a crosslinking reaction product of an electron-accepting compound having a crosslinking group and the coating film laminated thereon become stable. The fluorine-substituted alkyl group is preferably bonded to the para position of the boron atom.

The tetraarylborate ion further increases ^the stability ^of the anion and ^further _improves the effect of stabilizing the cation. At least one of (R ⁸² ) ₅ , *-Ph ³ -(R ⁸³ ) ₅ , *-Ph ⁴ -(R ⁸⁴ ) ₅ , (* represents a bond with boron B in formula (82)) It is preferable that it is a group represented by the following formula (84) having four fluorine atoms, and it is preferable that at least two groups are represented by the same formula (84) in terms of improving the stability of the anion. More preferably, it is most preferable that at least three groups are represented by the same formula (84), since the stability of the anion is further improved.

(In formula (84), * represents a bond with boron B of formula (82), F ₄ represents substitution with 4 fluorine atoms,
R ⁸⁵ represents an aromatic hydrocarbon group that may have a substituent or a crosslinking group. )

The aromatic hydrocarbon group that can be used for R ⁸⁵ preferably has 3 to 40 carbon atoms. The aromatic hydrocarbon ring structure is preferably a monocyclic ring, 2 to 6 condensed rings, or a structure in which 2 to 5 of these rings are connected. Specifically, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring, biphenyl structure, terphenyl structure. , a single monovalent group having a quaterphenyl structure, and a monovalent group in which 2 to 6 of these are linked. The crosslinking group that the aromatic hydrocarbon group may have is a crosslinking group selected from the group T of crosslinking groups.

The crosslinking group that can be used for R ⁸⁵ is preferably a crosslinking group selected from the group T of crosslinking groups.
The aromatic hydrocarbon group and the substituent which is not a crosslinking group that the aromatic hydrocarbon group may have are preferably groups selected from the substituent group Z, and among them, the aromatic hydrocarbon group is preferable from the viewpoint of stability. Preferably, an alkyl group is preferred from the viewpoint of solubility.

<Ionic compound containing tetraarylborate ion>
Tetraarylborate ions are used as electron-accepting ion compounds containing tetraarylborate ions.

(anti-cation)
The counter cation is preferably an iodonium cation, a sulfonium cation, a carbocation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptyltrienyl cation or a ferrocenium cation having a transition metal; Ammonium cations are more preferred, and iodonium cations are particularly preferred.

Preferably, the iodonium cation has a structure represented by the following formula (4), and a more preferable structure is also the same.

Specific examples of the iodonium cation include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, 4-tert-butoxyphenylphenyliodonium cation, 4-methoxyphenylphenyliodonium cation, and 4-isopropylphenyl-4-methyl. Preferred are phenyl iodonium cations and the like.

Specifically, the sulfonium cations include triphenylsulfonium cation, 4-hydroxyphenyldiphenylsulfonium cation, 4-cyclohexylphenyldiphenylsulfonium cation, 4-methanesulfonylphenyldiphenylsulfonium cation, (4-tert-butoxyphenyl)diphenylsulfonium cation, Bis(4-tert-butoxyphenyl)phenylsulfonium cation, 4-cyclohexylsulfonylphenyldiphenylsulfonium cation and the like are preferred.

Specifically, preferred carbocations include trisubstituted carbocations such as triphenylcarbocation, tri(methylphenyl)carbocation, and tri(dimethylphenyl)carbocation.

Specifically, the ammonium cation includes trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, tributylammonium cation, and tri(n-butyl)ammonium cation; N,N-diethylanilinium cation, N , N-2,4,6-pentamethylanilinium cations; and dialkylammonium cations such as di(isopropyl)ammonium cations and dicyclohexylammonium cations.

Specifically, the phosphonium cations include tetraarylphosphonium cations such as tetraphenylphosphonium cation, tetrakis(methylphenyl)phosphonium cation, and tetrakis(dimethylphenyl)phosphonium cation; tetraalkylphosphonium cations such as tetrabutylphosphonium cation and tetrapropylphosphonium cation. etc. are preferred.

Among these, iodonium cations, carbocations, and sulfonium cations are preferred from the viewpoint of film stability of the compound, and iodonium cations are more preferred.

(X ⁺ : iodonium cation)
The counter cation X ⁺ in the formula (81) is preferably an iodonium cation having the structure of the following formula (83).

In formula (83), Ar ⁸¹ and Ar ⁸² are each independently an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent.
The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, and most preferably a phenyl group. The substituents that may be included are groups selected from the above-mentioned substituent group Z, and among them, the most preferred is an alkyl group.
Preferred aromatic hydrocarbon groups include phenyl group, biphenyl group, terphenyl group, quaterphenyl group, naphthyl group, phenanthrenyl group, triphenylene group, naphthylphenyl group, etc., with phenyl group being the most preferred from the viewpoint of stability of the compound. preferable.

(molecular weight)
The molecular weight of the electron-accepting compound of the present invention is usually in the range of 900 or more, preferably 1,000 or more, more preferably 1,200 or more, and usually 10,000 or less, preferably 5,000 or less, and still more preferably 3,000 or less. If the molecular weight is too small, electron-accepting ability may be reduced due to insufficient delocalization of positive and negative charges, and if the molecular weight is too large, charge transport may be hindered.

(Concrete example)
Specific examples of the electron-accepting compound of the present invention represented by formula (81) are listed below, but the present invention is not limited thereto.

[Charge transporting polymer compound]
The composition of the present invention preferably contains a hole transporting polymer compound as the charge transporting polymer compound. The hole-transporting polymer compound is usually used to form a hole-injection layer or a hole-transporting layer, and is included in the charge-transporting film-forming composition described below. In this case, the composition of the present invention can be used to form a hole injection layer or a hole transport layer.

[Polymer containing arylamine structure as a repeating unit]
Preferably, the hole-transporting polymer compound is a polymer containing the following arylamine structure as a repeating unit and having a crosslinking group.
The repeating unit of the arylamine structure of the polymer having the arylamine structure as a repeating unit is represented by the following formula (50).

The substituent that Ar ⁵¹ and Ar ⁵² may have is preferably a substituent or a crosslinking group selected from the above substituent group Z.

When Ar ⁵¹ and Ar ⁵² have a crosslinking group, the crosslinking group is preferably a crosslinking group selected from the group T of crosslinking groups.

(terminal group)
As used herein, the term "terminal group" refers to a structure at the end of a polymer formed by an end-capping agent used at the end of polymerization of the polymer. In the composition of the present invention, the terminal group of the polymer containing the repeating unit represented by formula (50) is preferably a hydrocarbon group. From the viewpoint of charge transport properties, the hydrocarbon group is preferably a hydrocarbon group having 1 or more and 60 or less carbon atoms, more preferably a hydrocarbon group having 1 or more and 40 or less carbon atoms, and even more preferably a hydrocarbon group having 1 or more and 30 or less carbon atoms.

As the hydrocarbon group, for example,
Carbon atoms such as 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, etc. A straight chain, branched, or cyclic alkyl group whose number is usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less;
A linear, branched, or cyclic alkenyl group, such as a vinyl group, which usually has 2 or more and 24 or less carbon atoms, preferably 12 or less;
A linear or branched alkynyl group, such as an ethynyl group, which usually has 2 or more and 24 or less carbon atoms, preferably 12 or less;
An aromatic hydrocarbon group, such as a phenyl group or a naphthyl group, whose carbon number is usually 6 or more and 36 or less, preferably 24 or less;
Examples include crosslinking groups that are hydrocarbon groups in the crosslinking group group T; preferably crosslinking groups represented by the formulas (X1) to (X4).

These hydrocarbon groups may further have a substituent, and the optional substituent is preferably an alkyl group or an aromatic hydrocarbon group. When there are a plurality of substituents that may be further included, they may be bonded to each other to form a ring. When these hydrocarbon groups are groups other than crosslinking groups, the substituent may further have a crosslinking group selected from the group T of crosslinking groups.

The terminal group is preferably an alkyl group, an aromatic hydrocarbon group, or a crosslinking group that is a hydrocarbon group in the crosslinking group group T, more preferably an aromatic group, from the viewpoint of charge transport properties and durability. When it is a hydrocarbon group and the terminal group is not a crosslinking group, it is also preferable that it further has a crosslinking group selected from the group T of crosslinking groups.

( ^Ar52 )
Ar ⁵² is at least one selected from the group consisting of a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group. One group represents a divalent group in which a plurality of groups are connected directly or via a linking group, and the aromatic hydrocarbon group and the aromatic heterocyclic group may have a substituent.
The optional substituent is preferably a substituent or a crosslinking group selected from the above-mentioned substituent group Z. When Ar ⁵² has a crosslinking group, the crosslinking group is preferably a crosslinking group selected from the group T of crosslinking groups.

(Twisted structure)
As for the repeating unit represented by the above formula (50), including the partial structure represented by the following formula (63) in the main chain structure represented by Ar ⁵² results in a twisted structure of the main chain, resulting in a conjugated It inhibits and is preferable.

(In formula (63),
R ⁶⁰¹ is an alkyl group that may have a substituent,
Ar ⁶²¹ is a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent,
Ring Ar represents an aromatic hydrocarbon structure that may have a substituent, a divalent aromatic heterostructure that may have a substituent,
-* represents a bond with an adjacent atom. )
In addition, in Ar ⁵² of the repeating unit of the arylamine structure represented by the above formula (50), it does not matter whether it is on the left or right side in the above formula (63). That is, the following formula (63') is also synonymous with the above formula (63).

( ^Ar51 )
Ar ⁵¹ represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected; The aromatic heterocyclic group may have a substituent.
The optional substituent is preferably a substituent or a crosslinking group selected from the above substituent group Z, and when it has a crosslinking group, the crosslinking group is preferably a crosslinking group selected from the above crosslinking group T. .

(Preferred structure of Ar ⁵¹ having a bridging group)
When Ar ⁵¹ has a crosslinking group, Ar ⁵¹ preferably has a crosslinking group selected from the group T of crosslinking groups at the terminal of a monovalent group in which 2 to 5 benzene rings which may have substituents are connected. A structure having a group is preferred. More preferably, Ar ⁵¹ has a structure having a crosslinking group selected from the group T of crosslinking groups at the end of a monovalent group in which 2 to 5 unsubstituted benzene rings are connected.

<Preferred Ar ⁵¹ >
Ar ⁵¹ is preferably an aromatic hydrocarbon group from the viewpoint of excellent charge transport properties and durability, and among them, a benzene ring (phenyl group), a group in which 2 to 5 benzene rings are connected, or a fluorene ring. A valent group (fluorenyl group) is more preferred, a fluorenyl group is even more preferred, and a 2-fluorenyl group is particularly preferred. These may have substituents. As the substituent, a group selected from the above-mentioned substituent group Z or a crosslinking group is preferable. When it has a crosslinking group, the crosslinking group is preferably a crosslinking group selected from the group T of crosslinking groups.

There are no particular limitations on the substituents that the aromatic hydrocarbon group and aromatic heterocyclic group of Ar ⁵¹ may have, as long as they do not significantly reduce the properties of the present polymer. The substituent is preferably a group selected from substituent group Z described below, more preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, and even more preferably an alkyl group.

From the viewpoint of solubility in a solvent, Ar ⁵¹ is preferably a fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms, and particularly preferably a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms. . Furthermore, a 9-alkyl-2-fluorenyl group in which the 9-position of the 2-fluorenyl group is substituted with an alkyl group is preferred, and a 9,9'-dialkyl-2-fluorenyl group in which the 9-position of the 2-fluorenyl group is substituted with an alkyl group is particularly preferred.

When at least one of the 9-position and 9'-position is a fluorenyl group substituted with an alkyl group, the solubility in solvents and the durability of the fluorene ring tend to improve. Furthermore, since both the 9-position and the 9'-position are fluorenyl groups substituted with alkyl groups, the solubility in solvents and the durability of the fluorene ring tend to be further improved.

Further, Ar ⁵¹ is also preferably a spirobifluorenyl group from the viewpoint of solubility in a solvent.

Further, as a polymer containing a repeating unit represented by the formula (50), Ar ⁵¹ in the repeating unit represented by the formula (50) is a group represented by the following formula (51), a group represented by the following formula ( It is preferable to include a repeating unit which is a group represented by 52) or a group represented by the following formula (53).

(In formula (51),
* represents a bond with the nitrogen atom in the main chain of formula (50),
Ar ⁵³ and Ar ⁵⁴ are each independently an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a substituent-containing divalent aromatic hydrocarbon group; represents a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are connected directly or via a connecting group,
Ar ⁵⁵ is an aromatic hydrocarbon group that may have a substituent, an aromatic heterocyclic group that may have a substituent, an aromatic hydrocarbon group that may have a substituent, or an aromatic Represents a monovalent group in which a plurality of group heterocyclic groups are connected directly or via a linking group,
Ar ⁵⁶ represents a hydrogen atom or a substituent. )

Here, each aromatic hydrocarbon group and each aromatic heterocyclic group may have a substituent. The optional substituent is preferably a group selected from the substituent group Z or a crosslinking group, and when a crosslinking group is included, the crosslinking group is preferably a group selected from the crosslinking group T.

( ^Ar53 )
Ar ⁵³ is preferably a group in which 1 to 6 divalent aromatic hydrocarbon groups are connected, more preferably a group in which 2 to 4 divalent aromatic hydrocarbon groups are connected, and among them, a group in which 1 to 4 phenylene rings are connected. A group in which two phenylene rings are connected is more preferable, and a biphenylene group in which two phenylene rings are connected is particularly preferable.

These groups may have a substituent. The optional substituent is preferably a group selected from the substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups. Preferably, Ar ⁵³ is free of substituents and bridging groups.

Furthermore, when a plurality of these divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are connected, the group is preferably bonded so that the plurality of connected divalent aromatic hydrocarbon groups are not conjugated.
Specifically, it is preferable to include a 1,3-phenylene group or a group having a substituent and forming a twisted structure due to the steric effect of the substituent, and more preferably a 1,3-phenylene group having no substituent or crosslinking group. , 3-phenylene group, or a group in which a plurality of 1,3-phenylene groups having no substituent or crosslinking group are connected.

( ^Ar54 )
Ar ⁵⁴ is preferably a group in which one or more divalent aromatic hydrocarbon groups, which may be the same or different, are connected, from the viewpoint of excellent charge transport properties and durability; The group hydrocarbon group may have a substituent. When a plurality of groups are connected, the number of groups to be connected is preferably 2 to 10, more preferably 6 or less, and particularly preferably 3 or less from the viewpoint of membrane stability. Preferred aromatic hydrocarbon ring structures include benzene rings, naphthalene rings, anthracene rings, and fluorene rings, and more preferred are benzene rings and fluorene rings. As the group in which a plurality of phenylene rings are connected, a group in which 1 to 4 phenylene rings are connected, or a group in which a phenylene ring and a fluorene ring are connected is preferable. A biphenylene group in which two phenylene rings are connected is particularly preferred from the viewpoint of broadening the LUMO.

These groups may have a substituent. The optional substituent is preferably a group selected from the substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups. More preferred substituents are phenyl, naphthyl, and fluorenyl. Moreover, it is also preferable that it has no substituent.

( ^Ar55 )
Ar ⁵⁵ is an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or It is a monovalent group in which a plurality of aromatic heterocyclic groups are connected directly or via a linking group. Preferably, it is a monovalent aromatic hydrocarbon group or a group in which a plurality of monovalent aromatic hydrocarbon groups are connected.

These groups may have a substituent. The optional substituent is preferably a group selected from the substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups.

When a plurality of these groups are connected, it is preferably a divalent group in which 2 to 10 groups are connected, and a monovalent group in which 2 to 5 groups are connected. As the aromatic hydrocarbon group and aromatic heterocyclic group, the same aromatic hydrocarbon group and aromatic heterocyclic group as in Ar ⁵¹ above can be used.

It is preferable that Ar ⁵⁵ has a structure represented by any one of the following schemes 2A, 2B, and 2C.

In the above schemes 2A to 2C, "-*" represents the bonding position with Ar ⁵⁴ , and if there are multiple "-*", one represents the bonding position with Ar ⁵⁴ .
These structures may have substituents. As the substituent that these structures may have, a group selected from the above-mentioned substituent group Z or a crosslinking group is preferable. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups.

(R ³¹ and R ³² )
It is preferable that R ³¹ and R ³² in Schemes 2A and 2B are each independently a linear, branched or cyclic alkyl group which may have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more and 6 or less, more preferably 3 or less, and even more preferably a methyl group or an ethyl group. .

R ³¹ and R ³² may be the same or different, but since the charge can be uniformly distributed around the nitrogen atom and synthesis is easy, all R ³¹ and R ³² are preferably the same group.

(Ar ^d18 )
Each Ar ^d18 in Scheme 2B is independently an aromatic hydrocarbon group or an aromatic heterocyclic group. From the viewpoint of stability, Ar ^d18 is preferably an aromatic hydrocarbon group, and more preferably a phenyl group. These groups may further have a substituent or a crosslinking group. The optional substituent is preferably a group selected from the substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups.

From the viewpoint of distributing the LUMO of the molecule, Ar ⁵⁵ includes the above a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-18, and e- Structures selected from 1 to e-4 are preferred. Furthermore, from the viewpoint of promoting the broadening of the LUMO of the molecule by having an electron-withdrawing group, a-1 to a-4, b-1 to b-9, d-1 to d-12, d-17, Structures selected from d-18 and e-1 to e-4 are preferred. Furthermore, from the viewpoint of the effect of confining excitons formed in the light emitting layer, which has a high triplet level, a-1 to a-4, d-1 to d-12, d-17, d-18, and e- Structures selected from 1 to e-4 are preferred. Further, from the viewpoint of easy synthesis and excellent stability, d-1, d-10, d-17, d-18 and e-1 are more preferable, and d-1 has a benzene ring structure and d-6 has a fluorene ring structure. A ring structure or a d-17 carbazole structure is particularly preferred.

When Ar ⁵⁵ is a fluorene structure represented by d-6, a 2-fluorenyl group is preferred. Furthermore, the 9 and 9' positions may have a substituent, and the substituent that may be present is preferably a group selected from the above-mentioned substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups. Among the substituents, alkyl groups are preferred.

( ^Ar56 )
Ar ⁵⁶ represents a hydrogen atom or a substituent. When Ar ⁵⁶ is a substituent, it is preferably an aromatic hydrocarbon group, an aromatic heterocyclic group, or a bridging group, although it is not particularly limited. In the case of an aromatic hydrocarbon group and an aromatic heterocyclic group, it is further substituted. It may have a substituent selected from group Z or a crosslinking group. When Ar ⁵⁶ is a crosslinking group, it is preferably a crosslinking group selected from the group T of crosslinking groups.

When Ar ⁵⁶ is a substituent, it is preferable from the viewpoint of improving durability that it is bonded to the 3-position of the carbazole structure to which Ar ⁵⁶ is bonded in formula (51). Ar ⁵⁶ is preferably a hydrogen atom from the viewpoint of ease of synthesis and charge transport properties. From the viewpoint of improving durability and charge transportability, Ar ⁵⁶ is preferably an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent. , an aromatic hydrocarbon group which may have a substituent is more preferable.

Ar ⁵⁶ is preferably a hydrogen atom from the viewpoint of ease of synthesis and charge transport properties.

(Specific example of group represented by formula (51))
Specific examples of the group represented by formula (51) are listed below, but the group represented by formula (51) is not limited to these.

(In formula (52),
Ar ⁶¹ and Ar ⁶² each independently represent an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted divalent aromatic heterocyclic group, or a substituent A divalent group in which a plurality of aromatic hydrocarbon groups that may have or aromatic heterocyclic groups that may have substituents are connected directly or via a linking group,
Ar ⁶³ to Ar ⁶⁵ each independently represent a hydrogen atom or a substituent.
* represents the bonding position to the nitrogen atom of the main chain in formula (50). )

The substituents that each aromatic hydrocarbon group may have, the substituents that each aromatic heterocyclic group may have, and Ar ⁶³ to Ar ⁶⁵ when they are substituents are from the substituent group Z. Selected groups or bridging groups are preferred.
A crosslinking group that each aromatic hydrocarbon group may have, a crosslinking group that each aromatic heterocyclic group may have, and Ar ⁶³ to Ar ⁶⁵ in the case of a crosslinking group are from the crosslinking group T. The selected groups are preferred.

(Ar ⁶³ ~ Ar ⁶⁵ )
Ar ⁶³ to Ar ⁶⁵ are each independently the same as Ar ⁵⁶ above.
Ar ⁶³ to Ar ⁶⁵ are preferably hydrogen atoms.

( ^Ar62 )
Ar ⁶² is a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent aromatic heterocyclic group which may have a substituent. It is a divalent group in which a plurality of aromatic hydrocarbon groups or aromatic heterocyclic groups which may have substituents are connected directly or via a connecting group.
Preferably, it is a divalent aromatic hydrocarbon group which may have a substituent or a group in which a plurality of divalent aromatic hydrocarbon groups which may have a substituent are connected. Here, the substituent that the aromatic hydrocarbon group may have and the substituent that the aromatic heterocyclic group may have are preferably the same groups as the above-mentioned substituent group Z or a crosslinking group. The crosslinking group, which is preferably a crosslinking group, is preferably a group selected from the group T of crosslinking groups.

The specific structure of Ar ⁶² is similar to Ar ⁵⁴ .

A specific preferred group for Ar ⁶² is a divalent group such as a benzene ring, a naphthalene ring, an anthracene ring, a fluorene ring, or a group in which a plurality of these are connected, and more preferably a divalent group in which a benzene ring or a plurality of these are connected. A linked group, particularly preferably a 1,4-phenylene group in which a benzene ring is linked at a divalent position at the 1 and 4 positions, a 2,7-fluorenylene group linked at a divalent position at the 2 and 7 positions of a fluorene ring, Or a group in which a plurality of these are connected, most preferably a group containing "1,4-phenylene group-2,7-fluorenylene group-1,4-phenylene group-".

In these preferred structures of Ar ⁶² , it is preferable that the phenylene group has no substituent or crosslinking group other than at the linking position to avoid twisting of Ar ⁶² due to the steric effect of the substituent. Further, it is preferable that the fluorenylene group has a substituent at the 9,9' position from the viewpoint of improving solubility and durability of the fluorene structure. As the substituent, a substituent or a crosslinking group selected from the above-mentioned substituent group Z is preferable, and an alkyl group is particularly preferable. These substituents may be further substituted with a crosslinking group. The crosslinking group is preferably a crosslinking group selected from the group T of crosslinking groups. Preferred are substituents selected from substituent group Z.

( ^Ar61 )
Ar ⁶¹ is the same group as Ar ⁵³ above, and its preferred structure is also the same.

(Specific example of group represented by formula (52))
Specific examples of the group represented by formula (52) are listed below, but the group represented by formula (52) is not limited to these.

(In formula (53),
* represents a bond with the nitrogen atom in the main chain of formula (50),
Ar ⁷¹ represents a divalent aromatic hydrocarbon group,
Ar ⁷² and Ar ⁷³ each independently represent an aromatic hydrocarbon group, an aromatic heterocyclic group, or two or more groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group directly or through a linking group. represents a monovalent group in which multiple groups are connected, and these groups may have a substituent,
Ring HA is an aromatic heterocycle containing a nitrogen atom,
X ² and Y ² each independently represent a carbon atom or a nitrogen atom, and when at least one of X ² and Y ² is a carbon atom, the carbon atom may have a substituent. )

The above optional substituent is preferably a group selected from the substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups.

<Ar ⁷¹ >
Ar ⁷¹ is the same group as Ar ⁵³ above.

As Ar ⁷¹ , a group in which 2 to 6 benzene rings which may have a substituent are connected is particularly preferable, and a quaterphenylene group in which 4 benzene rings which may have a substituent are connected is particularly preferable. Most preferred.

Further, Ar ⁷¹ preferably contains at least one benzene ring connected at the 1 and 3 positions, which are non-conjugated sites, and more preferably contains two or more.

In the case where Ar ⁷¹ is a group in which a plurality of divalent aromatic hydrocarbon groups which may have substituents are connected, it is preferable that all of them are directly bonded and connected from the viewpoint of charge transportability or durability. .

Therefore, as Ar ⁷¹ , preferable structures connecting the nitrogen atom of the main chain of the polymer and the ring HA in the formula (53) are as listed in Scheme 2-1 and Scheme 2-2 below. be. "-*" represents a nitrogen atom in the main chain of the polymer or a bonding site with ring HA of the formula (53). Either of the two "-*" may be bonded to the nitrogen atom of the main chain of the polymer, or may be bonded to ring HA.

As the substituent that Ar ⁷¹ may have, any one of the above substituent group Z or a combination thereof can be used. The preferred range of the substituents that Ar ⁷¹ may have is the same as the substituents that Ar ⁵³ may have when it is an aromatic hydrocarbon group.

<X ² and Y ² >
X ² and Y ² each independently represent a C (carbon) atom or an N (nitrogen) atom. When at least one of X ² and Y ² is a C atom, it may have a substituent.

From the viewpoint of making it easier to localize LUMO around ring HA, it is preferable that both X ² and Y ² are N atoms.

As the substituent that may be present when at least one of X ² and Y ² is a C atom, any one of the substituent group Z or a combination thereof can be used. From the viewpoint of charge transport properties, it is more preferable that X ² and Y ² have no substituents.

<Ar ⁷² and Ar ⁷³ >
Ar ⁷² and Ar ⁷³ each independently represent an aromatic hydrocarbon group, an aromatic heterocyclic group, or two or more groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group directly or through a linking group. It is a monovalent group in which multiple groups are connected. These groups may have a substituent, and the substituent that they may have is preferably a group selected from the above-mentioned substituent group Z or a crosslinking group. When it has a crosslinking group, the crosslinking group is preferably a group selected from the group T of crosslinking groups.

From the viewpoint of distributing the LUMO of the molecule, Ar ⁷² and Ar ⁷³ are each independently a-1 to a-4, b-1 to b-9, and c-1 to c-4 shown in Schemes 2A to 2C above. , d-1 to d-16, and e-1 to e-4.
Furthermore, from the viewpoint of promoting the broadening of the LUMO of the molecule by having an electron-withdrawing group, a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to Structures selected from d-12 and e-1 to e-4 are preferred.
Furthermore, from the viewpoint of having a high triplet level and an effect of confining excitons formed in the light emitting layer, it is selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4. Structure is preferred.
In order to prevent molecular aggregation, structures selected from d-1 to d-12 and e-1 to e-4 are more preferred. From the viewpoint of easy synthesis and excellent stability, Ar ⁷² =Ar ⁷³ = d-1 or d-10 is preferred, and the benzene ring structure of d-1 is particularly preferred.
Moreover, these structures may have substituents.

(Specific example of group represented by formula (53))
Specific examples of the group represented by formula (53) are listed below, but the group represented by formula (53) is not limited to these.

(Repeating unit represented by preferred formula (50))
The repeating unit represented by the formula (50) is preferably a repeating unit represented by the following formula (54), a repeating unit represented by the following formula (55), or a repeating unit represented by the following formula (56). , a repeating unit represented by the following formula (57), and a repeating unit represented by the following formula (60). It is more preferable that the repeating unit represented by the formula (50) is a repeating unit represented by the following formula (54).

(R ²⁰¹ , R ²⁰² , R ²²¹ , R ²²² )
R ²⁰¹ , R ²⁰² , R ²²¹ and R ²²² in the repeating unit represented by the above formula (54) are each independently an alkyl group which may have a substituent. It is preferable that R ²⁰¹ , R ²⁰² , R ²²¹ and R ²²² have no substituent.

The alkyl group is a linear, branched or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more, preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. More preferably, the alkyl group is a methyl group or an ethyl group.

When there is a plurality of R ^201s , the plurality of R ^201s may be the same or different; when there is a plurality of R ^202s , the plurality of R ^202s may be the same or different. It is preferable that all R ²⁰¹ and R ²⁰² are the same group because the charge can be uniformly distributed around the nitrogen atom and synthesis is also easy.

When there are multiple R ^221s , the multiple R ^221s may be the same or different; when there are multiple R ^222s , the multiple R ^222s may be the same or different. For ease of synthesis, it is preferred that all R ²²¹ and R ²²² are the same group.

(R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ )
R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a hydrogen atom, an aralkyl group which may have a substituent, or a substituent This is an optionally aromatic hydrocarbon group. R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ preferably have no substituent.

The alkyl group is not particularly limited, but since it tends to improve the solubility of the polymer, the number of carbon atoms is preferably 1 or more, preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less. Further, the alkyl group may have a linear, branched or cyclic structure.

Specific examples of the alkyl group include 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.

The aralkyl group is not particularly limited, but since it tends to improve the solubility of the polymer, the number of carbon atoms is preferably 5 or more, preferably 60 or less, and more preferably 40 or less.

Specifically, the aralkyl group includes a 1,1-dimethyl-1-phenylmethyl group, a 1,1-di(n-butyl)-1-phenylmethyl group, and a 1,1-di(n-hexyl)- 1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group , 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1- Examples include n-heptyl group, 8-phenyl-1-n-octyl group, and 4-phenylcyclohexyl group.

The aromatic hydrocarbon group is not particularly limited, but since it tends to improve the solubility of the polymer, the number of carbon atoms is preferably 6 or more, preferably 60 or less, and more preferably 30 or less.

Specifically, the aromatic hydrocarbon group includes 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, and a fluorene ring. Examples include monovalent groups such as a 6-membered monocyclic ring or 2 to 5 condensed rings, or a group in which a plurality of these are connected.

From the viewpoint of improving charge transport properties and durability, R ²⁰⁷ and R ²⁰⁸ are preferably a methyl group or an aromatic hydrocarbon group, R ²⁰⁷ and R ²⁰⁸ are more preferably a methyl group, and R ²⁰⁹ is a phenyl group. It is more preferable.

The alkyl groups of R ²⁰¹ , R ²⁰² , R ²²¹ , and R ²²² , the alkyl groups, aralkyl groups, and aromatic hydrocarbon groups of R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ may have a substituent. Examples of the substituent include the groups or crosslinking groups listed as preferred groups for the alkyl group, aralkyl group, and aromatic hydrocarbon group of R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ above.
Examples of the crosslinking group include crosslinking groups selected from the group T of crosslinking groups.

The alkyl groups of R ²⁰¹ , R ²⁰² , R ²²¹ , and R ²²² , the alkyl groups, aralkyl groups, and aromatic hydrocarbon groups of R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ are considered substituents from the viewpoint of lowering the voltage. Most preferably, it does not have.

When a crosslinking group is bonded to the main chain structure of the repeating unit represented by formula (54), the crosslinking group is an alkyl group, an aralkyl group, or an aromatic hydrocarbon group, R ²⁰⁷ to R ²⁰⁹ , R ²¹¹ -R ²¹³ or R ²¹⁴ is preferable.

(a, b, c and d)
In the repeating unit represented by the above formula (54), a and b are each independently an integer of 0 to 4. a+b is preferably 1 or more, furthermore, a and b are each preferably 2 or less, and more preferably both a and b are 1. Here, when b is 1 or more, d is also 1 or more. Moreover, when c is 2 or more, a plurality of a's may be the same or different, and when d is 2 or more, a plurality of b's may be the same or different.

When a+b is 1 or more, the aromatic ring in the main chain is twisted due to steric hindrance, and the polymer has excellent solubility in solvents, and a coating film formed by a wet film forming method and heat-treated is insoluble in solvents. They tend to be excellent at Therefore, when a+b is 1 or more, when forming another organic layer (e.g., a light-emitting layer) on this coating film by a wet film formation method, use a composition for forming another organic layer containing an organic solvent. The elution of the polymer is suppressed.

In the repeating unit represented by the above formula (54), c is an integer of 0 to 3, and d is an integer of 0 to 4. Each of c and d is preferably 2 or less, more preferably c and d are equal, and particularly preferably both c and d are 1 or both c and d are 2.

When both c and d in the repeating unit represented by the above formula (54) are 1, or both c and d are 2, and both a and b are 2 or 1, R Most preferably, ²⁰¹ and R ²⁰² are bonded to positions symmetrical to each other.

Here, the expression that R ²⁰¹ and R ²⁰² are bonded to positions symmetrical to each other means that the bonding positions of R ²⁰¹ and R ²⁰² are relative to the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure in formula (54). is symmetrical. At this time, 180 degree rotation around the main chain is considered to be the same structure.

When present, R ²²¹ and R ²²² are preferably present independently at the 1st, 3rd, 6th, or 8th position with respect to the carbon atom of the benzene ring to which X is bonded. The presence of R ²²¹ and/or R ²²² at this position causes the condensed ring to which R ²²¹ and/or R ²²² is bonded and the adjacent benzene ring on the main chain to be twisted due to steric hindrance, resulting in a polymer In addition to having excellent solubility in solvents, coating films formed by a wet film forming method and heat-treated tend to have excellent insolubility in solvents, and are therefore preferred.

(i, j)
In the repeating unit represented by the above formula (54), i and j are each independently an integer of 0 to 3. i and j are each independently preferably an integer of 0 to 2, more preferably 0 or 1. Preferably, i and j are the same integer. In order to twist the main chain of the polymer, i and j are preferably 1 or 2, and R ²²¹ and/or R ²²² are preferably bonded to the 1st and/or 3rd positions of the benzene ring. . From the viewpoint of ease of synthesis, it is preferable that i and j are 0. In addition, the bonding position of the benzene ring is the carbon atom next to the carbon atom to which X is bonded, and the carbon atom to which R ²²¹ or R ²²² can be bonded is the 1st position, and is bonded to the adjacent structure as the main chain. The carbon atom is at the 2nd position.

(X)
X in the above formula (54) is preferably -C(R ²⁰⁷ )(R ²⁰⁸ )- or -N(R ²⁰⁹ )-, and -C(R ²⁰⁷ )(R ²⁰⁸ )- is more preferable.

(Preferred repeating unit)
The repeating unit represented by the above formula (54) is particularly preferably a repeating unit represented by any of the following formulas (54-1) to (54-8).

In the above formula, R ²⁰¹ and R ²⁰² are the same, and R ²⁰¹ and R ²⁰² are bonded to positions symmetrical to each other.

<Preferred example of main chain of repeating unit represented by formula (54)>
Although the main chain structure excluding the nitrogen atom in the above formula (54) is not particularly limited, for example, the following structures are preferable.

(In formula (55),
Ar ⁵¹ is the same as Ar ⁵¹ in the above formula (54),
R ³⁰³ and R ³⁰⁶ are each independently an alkyl group that may have a substituent,
R ³⁰⁴ and R ³⁰⁵ are each independently an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or an aralkyl group that may have a substituent,
l is 0 or 1,
m is 1 or 2,
n is 0 or 1,
p is 0 or 1,
q is 0 or 1. )

(R ³⁰³ , R ³⁰⁶ )
R ³⁰³ and R ³⁰⁶ in the repeating unit represented by the above formula (55) are each independently an alkyl group which may have a substituent.

Examples of the alkyl group include those similar to R ²⁰¹ and R ²⁰² in the formula (54), and the substituents that may be included and preferred structures are also the same as R ²⁰¹ and R ²⁰² .

When there is a plurality of R ^303s , the plurality of R ^303s may be the same or different; when there is a plurality of R ^306s , the plurality of R ^306s may be the same or different.

(R ³⁰⁴ , R ³⁰⁵ )
R ³⁰⁴ and R ³⁰⁵ in the repeating unit represented by the above formula (55) are each independently an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or a substituted It is an aralkyl group which may have a group. Preferred is an alkyl group which may have a substituent.
Preferably, R ³⁰⁴ and R ³⁰⁴ are the same.

The alkyl group is a linear, branched or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but it is preferably 1 or more, more preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less, since it tends to improve the solubility of the polymer.

Specific examples of the alkyl group include 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. group, n-octyl group, cyclohexyl group, dodecyl group, etc.

The alkoxy group is not particularly limited, and the alkyl group represented by R ¹⁰ of the alkoxy group (-OR ¹⁰ ) may have a linear, branched, or cyclic structure, and improves the solubility of the polymer. Therefore, the number of carbon atoms is preferably 1 or more, preferably 24 or less, and more preferably 12 or less.

Specific examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, n-butoxy group, hexyloxy group, 1-methylpentyloxy group, and cyclohexyloxy group.

The aralkyl group is not particularly limited, but since it tends to improve the solubility of the polymer, it preferably has 5 or more carbon atoms, preferably 60 or less, and more preferably 40 or less.

Specifically, the aralkyl group includes a 1,1-dimethyl-1-phenylmethyl group, a 1,1-di(n-butyl)-1-phenylmethyl group, and a 1,1-di(n-hexyl) group. -1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1 Examples include -n-heptyl group, 8-phenyl-1-n-octyl group, and 4-phenylcyclohexyl group.

The substituents that the alkyl group, alkoxy group, and aralkyl group of R ³⁰⁴ and R ³⁰⁵ may have are the preferred groups of the alkyl group, aralkyl group, and aromatic hydrocarbon group of the above R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ . Examples include the groups listed above or crosslinking groups. Examples of the crosslinking group include crosslinking groups selected from the group T of crosslinking groups.

It is most preferable that the alkyl group, alkoxy group, and aralkyl group of R ³⁰⁴ and R ³⁰⁵ have no substituent from the viewpoint of lowering the voltage.

When a crosslinking group is bonded to the main chain structure of the repeating unit represented by formula (55), the crosslinking group is preferably bonded to R ³⁰⁴ and R ³⁰⁵ .

(l, m and n)
l represents 0 or 1, and n represents 0 or 1.

l and n are each independent, l+n is preferably 1 or more, more preferably 1 or 2, and even more preferably 2. When l+n is within the above range, the solubility of the polymer is increased and precipitation from the composition of the present invention containing the polymer tends to be suppressed.

m represents 1 or 2, and since the organic electroluminescent device manufactured using the composition of the present invention can be driven at low voltage and tends to improve hole injection ability, transport ability, and durability, 1 It is preferable that

(p and q)
p represents 0 or 1, and q represents 0 or 1. When l=n=1, p and q will never be 0 at the same time. Since p and q do not become 0 at the same time, the solubility of the polymer tends to be increased and precipitation from the composition of the present invention containing the polymer tends to be suppressed. In addition, for the same reasons as a and b above, when p+q is 1 or more, the aromatic ring in the main chain is twisted due to steric hindrance, and the polymer has excellent solubility in solvents and can be formed by wet film formation. Heat-treated coatings tend to be more insoluble in solvents. Therefore, when p+q is 1 or more, when another organic layer (e.g., a light-emitting layer) is formed on this coating film by a wet film formation method, it is difficult to use another organic layer-forming composition containing an organic solvent. The elution of the polymer is suppressed.

<Specific example of main chain of repeating unit represented by formula (55)>
The main chain structure excluding the nitrogen atom in formula (55) is not particularly limited, and examples include the following structures.

(In formula (56),
Ar ⁵¹ is the same as Ar ⁵¹ in the above formula (54),
Ar ⁴¹ is a divalent aromatic hydrocarbon group that may have a substituent, a divalent aromatic heterocyclic group that may have a substituent, or the divalent aromatic hydrocarbon group that may have a substituent. and a divalent group in which a plurality of at least one group selected from the group consisting of the divalent aromatic heterocyclic group are connected directly or via a linking group,
R ⁴⁴¹ and R ⁴⁴² are each independently an alkyl group that may have a substituent,
t is 1 or 2,
u is 0 or 1,
r and s are each independently an integer of 0 to 4. )

(R ⁴⁴¹ , R ⁴⁴² )
R ⁴⁴¹ and R ⁴⁴² in the repeating unit represented by the above formula (56) are each independently an alkyl group which may have a substituent.

The alkyl group is a linear, branched or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. More preferably, the alkyl group is a methyl group or a hexyl group.

When a plurality of R ⁴⁴¹ and R ⁴⁴² are present in the repeating unit represented by the above formula (56), the plurality of R ⁴⁴¹ and R ⁴⁴² may be the same or different.

(r, s, t and u)
In the repeating unit represented by formula (56), r and s are each independently an integer of 0 to 4. When t is 2, the plural r's may be the same or different. It is preferable that r+s is 1 or more, and furthermore, it is preferable that r and s are each 2 or less. When r+s is 1 or more, it is thought that the driving life of the organic electroluminescent device becomes even longer for the same reason as a and b in the above formula (54).

In the repeating unit represented by the above formula (56), t is 1 or 2, and u is 0 or 1. t is preferably 1, and u is preferably 1.

( ^Ar41 )
Ar ⁴¹ is a divalent aromatic hydrocarbon group that may have a substituent, a divalent aromatic heterocyclic group that may have a substituent, or the divalent aromatic hydrocarbon group that may have a substituent. and a divalent group in which a plurality of at least one group selected from the group consisting of the above-mentioned divalent aromatic heterocyclic groups are connected directly or via a connecting group.

Examples of the aromatic hydrocarbon group and the aromatic hydrocarbon group in Ar ⁴¹ include the same groups as Ar ⁵² in the formula (50). Further, the aromatic hydrocarbon group and the substituent which the aromatic hydrocarbon group may have are preferably groups selected from the above-mentioned substituent group Z, and the substituents which may further have are also preferably selected from the above-mentioned substituent group Z. It is preferable that it is similar to.

(In formula (57),
Ar ⁵¹ is the same as Ar ⁵¹ in the above formula (54),
R ⁵¹⁷ to R ⁵¹⁹ each independently represent an alkyl group that may have a substituent, an alkoxy group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. represents an aromatic hydrocarbon group that may have or an aromatic heterocyclic group that may have a substituent,
f, g, h each independently represent an integer from 0 to 4,
e represents an integer from 0 to 3,
However, when g is 1 or more, e is 1 or more. )

(R ⁵¹⁷ to R ⁵¹⁹ )
The aromatic hydrocarbon group and aromatic heterocyclic group in R ⁵¹⁷ to R ⁵¹⁹ are each independently the same groups as those listed for Ar ⁵¹ above, and the substituents that these groups may have The group is preferably the substituent group Z or a crosslinking group, and the crosslinking group is preferably a crosslinking group selected from the crosslinking group T.

The alkyl group and aralkyl group in R ⁵¹⁷ to R ⁵¹⁹ are preferably the same groups as those listed for R ²⁰⁷ above, and the substituents that may be further included are preferably the same groups as R ²⁰⁷ above.

The alkoxy group in R ⁵¹⁷ to R ⁵¹⁹ is preferably the alkoxy group listed in the above substituent group Z, and the optional substituent is preferably the above substituent group Z.

(f, g, h)
f, g, and h each independently represent an integer of 0 to 4.
When e is 2 or more, a plurality of g's may be the same or different.
It is preferable that f+g+h is 1 or more.
f+h is preferably 1 or more,
It is more preferable that f+h is 1 or more, and f, g and h are 2 or less,
More preferably, f+h is 1 or more, and f and h are 1 or less,
Most preferably, both f and h are 1.

When f and h are both 1, R ⁵¹⁷ and R ⁵¹⁹ are preferably bonded to positions symmetrical to each other.
Moreover, it is preferable that R ⁵¹⁷ and R ⁵¹⁹ are the same.

More preferably, g is 2.
When g is 2, the two R ^518s are most preferably attached to each other in the para position;
Most preferably when g is 2, the two R ^518s are the same.

Here, the expression that R ⁵¹⁷ and R ⁵¹⁹ are bonded to mutually symmetrical positions refers to the following bonding positions. However, for notation purposes, a 180 degree rotation around the main chain is considered to be the same structure.

In addition, when the polymer of this embodiment contains the repeating unit represented by formula (54) and the repeating unit represented by formula (57), the repeating unit represented by formula (54) and the repeating unit represented by formula (57) The ratio of (number of moles of repeating unit represented by formula (57))/(number of moles of repeating unit represented by formula (54)) to the repeating unit represented by formula (54) is preferably 0.1 or more, It is more preferably 0.3 or more, even more preferably 0.5 or more, even more preferably 0.9 or more, and particularly preferably 1.0 or more. Further, the ratio is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less.

Furthermore, the repeating unit represented by the formula (57) is preferably a repeating unit represented by the following formula (58).

In the case of the repeating unit represented by the above formula (58), it is preferable that g=0 or 2. When g=2, the bonding positions are the 2nd and 5th positions. When g = 0, that is, there is no steric hindrance due to R ⁵¹⁸ , and when g = 2 and the bonding positions are the 2nd and 5th positions, that is, the diagonal of the benzene ring to which two R ^518s are bonded with steric hindrance. In the case where R 517 and R 519 are bonded at symmetrical positions, R ⁵¹⁷ and R ⁵¹⁹ can be bonded at symmetrical positions.

Furthermore, the repeating unit represented by the formula (58) is more preferably a repeating unit represented by the following formula (59), where e=3.

In the case of the repeating unit represented by the above formula (59), it is preferable that g=0 or 2. When g=2, the bonding positions are the 2nd and 5th positions. When g = 0, that is, there is no steric hindrance due to R ⁵¹⁸ , and when g = 2 and the bonding positions are the 2nd and 5th positions, that is, a pair of benzene rings to which two R ^518s are bonded with steric hindrance. In the case of angular positions, R ⁵¹⁷ and R ⁵¹⁹ can be bonded at symmetrical positions.

<Specific example of main chain of repeating unit represented by formula (57)>
The main chain structure of the repeating unit represented by formula (57) is not particularly limited, and examples include the following structures.

It is preferable that the repeating units represented by the above formulas (50) to (59) do not have a crosslinking group. When the polymer does not have a crosslinking group, distortion of the polymer chain is less likely to occur during heating drying or baking after wet film formation, which is preferable. This is because a volume change may occur when the crosslinking group reacts, causing distortion of the polymer chain. Another reason is that distortion of the polymer chain occurs even if no volume change occurs.

(In formula (60),
Ar ⁵¹ is the same as Ar ⁵¹ in the above formula (50),
n ⁶⁰ represents an integer from 1 to 5. )

( ⁿ⁶⁰ )
n ⁶⁰ represents an integer of 1 to 5, preferably an integer of 1 to 4, and more preferably an integer of 1 to 3.

(Twisted structure that inhibits conjugation)
When the functional material used in the composition of the present invention is a polymer having a repeating unit represented by the formula (50), the repeating unit represented by the formula (50) is more preferably represented by the formula (54). A repeating unit represented by the formula (55), a repeating unit represented by the formula (56), or a repeating unit represented by the formula (57), particularly preferably a repeating unit represented by the formula (55). It is a repeating unit represented by (54). Further, the partial structure represented by the formula (63) is preferably a partial structure represented by the following formula (61) or the following formula (61'). Therefore, the repeating unit represented by the above formula (50) is more preferably a repeating unit represented by the above formula (54) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure. A repeating unit represented by the above formula (55) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure, a repeating unit represented by the following formula (61) or the following formula (61 ') as the main chain structure, or a repeating unit represented by the formula (56) below, or a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure. It is a repeating unit represented by the above formula (57) containing, and particularly preferably, a repeating unit represented by the above formula (54) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure. It is a repeating unit.

(In formula (61) and formula (61'),
R ⁶⁰¹ is R ²⁰¹ or R ²⁰² in formula (54), R ³⁰³ , R ³⁰⁴ , R ³⁰⁵ , or R ⁴⁰⁶ in formula (55), R ⁴⁴¹ or R ⁴⁴² in formula (56), R ⁵¹⁷ in formula (57) , R ⁵¹⁸ or R ⁵¹⁹ , and -* represents a bond with the adjacent atom.
When formula (61) is a partial structure of formula (54) or a partial structure of formula (56), Ring B may be part of a fused ring.
When formula (61') is a partial structure of formula (54) or a partial structure of formula (56), Ring B may be part of a fused ring.
In addition to R 601, the partial structures represented by formula (61) and formula (61') include R ²⁰¹ or R 202 in Ring A and Ring B when the partial structure is represented by formula (54), R ²⁰¹ or R ²⁰² , and the formula ( 55), R ³⁰³ , R ³⁰⁴ , R ³⁰⁵ , or R 306 , R ⁴⁴¹ or R 442 if the partial structure of formula (56), and R ⁴⁴¹ or R ⁴⁴² if the partial structure of formula (57) It may have R ⁵¹⁷ , R ⁵¹⁸ or R ⁵¹⁹ . )

(Formula (62))
The repeating unit represented by the formula (50) is particularly preferably a repeating unit represented by the formula (54) that includes a partial structure represented by the formula (61) or the formula (61') as the main chain structure. It is a polymer containing a repeating unit represented by the following formula (62).

(In formula (62),
^Ar51 , X, ^R201 , ^R202 , ^R221 , ^R222 , a, b, c, d are ^Ar51 , X, ^R201 , ^R202 , ^R221 , ^R222 , a in the formula (54) , b, c, d,
a ¹ , a ² , b ¹ , b ² , i ¹ , i ² , j ¹ , and j ² are each independently 0 or 1.
However, either of the following conditions (1) or (2) is satisfied.
(1) At least one of a ¹ , a ² and a is 1 or more,
At least one of b ¹ , b ² and b is 1 or more,
c is 1 or more, d is 1 or more,
When c is 1, at least one of a ¹ or a ² is 1,
When d is 1, at least one of b ¹ and b ² is 1.
(2) At least one of i ¹ , i ² , j ¹ and j ² is 1.
Ring A1 refers to a divalent benzene ring that may have R ²⁰¹ at a specific position,
Ring A2 is a divalent group in which c-1 benzene rings which may have R ²⁰¹ are connected; however, in the case of c=1, it refers to a monocyclic divalent benzene ring,
Ring A3 refers to a divalent fused ring in which the biphenyl structure is further bonded with X,
Ring A4 is a divalent group in which d-1 benzene rings which may have R ²⁰² are connected, however, in the case of d=1, it refers to a monocyclic divalent benzene ring,
Ring A5 refers to a divalent benzene ring that may have R ²⁰² at a specific position. )

Here, a being 1 or more in formula (54) is synonymous with at least one of a ¹ , a ² and a being 1 or more in formula (62), and in formula (54), a is 1 or more. The fact that b is 1 or more has the same meaning as that in formula (62), at least one of b ¹ , b ² and b is 1 or more. )

As shown below, formula (62) includes the above formula (61) or the above formula (61') as a partial structure.
When at least one of a ¹ , a ² and a is 1 or more,
When at least one of a ¹ or a ² is 1, when c is 2 or more, Ring A1 and Ring A2 are, and when c is 1, Ring A1 and Ring A3 are,
When a is 1, Ring A2 and Ring A1 or Ring A2 and Ring A3 contain the formula (61) or the formula (61') as a partial structure.
Similarly, it can be seen that when at least one of b ¹ , b ² and b is 1 or more, the formula (61) or the formula (61') is included as a partial structure.
Further, when at least one of i ¹ , i ² , j ¹ and j ² is 1,
When one or both of i ¹ and i ² is 1, the ring to which R ²²¹ of Ring A3 is bonded and the benzene ring of Ring A2 form formula (61') as a partial structure,
It can be seen that when one or both of j ¹ and j ² is 1, the ring to which R ²²² of Ring A3 is bonded and the benzene ring of Ring A4 form the formula (61) as a partial structure.
That is, it can be seen that Ring A3 and Ring A2 or Ring A3 and Ring A4 have a twisted structure.
Therefore, formula (62) includes a twisted structure in which the aromatic ring of the main chain is twisted, which is a twisted structure that inhibits conjugation and is preferable.

[Molecular weight of polymer]
The molecular weight of the polymer contained in the composition of the present invention will be described below.

The weight average molecular weight (Mw) of the polymer having the above-mentioned arylamine structure as a repeating unit is usually 1,000,000 or less, preferably 500,000 or less, more preferably 100,000 or less, and still more preferably 70,000. It is particularly preferably 50,000 or less. Further, the weight average molecular weight is usually 5,000 or more, preferably 10,000 or more, more preferably 12,000 or more, particularly preferably 15,000 or more.

When the weight average molecular weight of the polymer having the above-mentioned arylamine structure as a repeating unit is below the above-mentioned upper limit, solubility in a solvent is obtained and film-forming properties tend to be excellent. Furthermore, when the weight average molecular weight of the polymer is equal to or higher than the above lower limit, a decrease in the glass transition temperature, melting point, and vaporization temperature of the polymer may be suppressed, and heat resistance may be improved. In addition, the coating film after the crosslinking reaction may be sufficiently insoluble in organic solvents.

Further, the number average molecular weight (Mn) of the polymer having the above-mentioned arylamine structure as a repeating unit is usually 750,000 or less, preferably 250,000 or less, more preferably 100,000 or less, particularly preferably 50,000 or less. It is as follows. Further, the number average molecular weight is usually 2,000 or more, preferably 4,000 or more, more preferably 6,000 or more, and even more preferably 8,000 or more.

Further, the degree of dispersion (Mw/Mn) in the polymer having the above-mentioned arylamine structure as a repeating unit is preferably 3.5 or less, more preferably 2.5 or less, particularly preferably 2.0 or less. Note that the lower limit value is ideally 1, since the smaller the value of the degree of dispersion, the better. When the degree of dispersion of the polymer is less than or equal to the above upper limit, it is easy to purify and has good solubility in solvents and charge transport ability.

Usually, the weight average molecular weight and number average molecular weight of a polymer are determined by SEC (size exclusion chromatography) measurement. In SEC measurement, the elution time is shorter for higher molecular weight components, and the elution time is longer for lower molecular weight components. However, using a calibration curve calculated from the elution time of polystyrene (standard sample) of known molecular weight, the elution time of the sample can be adjusted to the molecular weight. By converting, the weight average molecular weight and number average molecular weight are calculated.

(Content of repeating unit represented by formula (50))
In the polymer, the content of the repeating unit represented by formula (50) is not particularly limited, but the repeating unit represented by formula (50) is usually 10 mol% or more in 100 mol% of the total repeating units of the polymer. The content is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more.

The repeating unit of the polymer may be composed only of the repeating unit represented by formula (50), but for the purpose of balancing various performances when used as an organic electroluminescent element, the repeating unit represented by formula (50) is It may have a repeating unit different from the repeating unit used. In that case, the content of the repeating unit represented by formula (50) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

<Repeating unit represented by formula (50-2)>
The polymer containing an arylamine structure as a repeating unit of the present invention may further contain a structure represented by the following formula (50-2) in the main chain.

(In the formula, R ⁸¹ and R ⁸³ each independently represent a hydrogen atom, an alkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group. If multiple R ⁸¹ and R ⁸³ exist, the same or may be different. ^p80 represents an integer from 1 to 5.)

When R ⁸¹ and R ⁸³ are an alkyl group, the alkyl group is a linear, branched or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more, preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. More preferably, the alkyl group is a methyl group or an ethyl group.

When R ⁸¹ and R ⁸³ are an aromatic hydrocarbon group or an aromatic heterocyclic group, the structures described in the "Definition" section above are preferred.

R ⁸¹ and R ⁸³ may have a substituent. The substituent is preferably a substituent or a crosslinking group selected from the above-mentioned substituent group Z. When it is a crosslinking group, a crosslinking group selected from the above-mentioned crosslinking group group T is preferable.

From the viewpoint of polymer durability and charge transportability, ^p80 is preferably 3 or less, more preferably 2 or less, and most preferably 1.

By including the structure represented by formula (50-2), the conjugation of the main chain of the polymer is cut, increasing the S1 energy level and T1 energy level of the polymer, and creating a composition containing this polymer. When used in the hole transport layer of an organic electroluminescent device, excitons in the light emitting layer are difficult to deactivate, and it is thought that the luminous efficiency is increased, which is preferable.

(Preferred repeating unit structure of polymer)
Here, in the repeating unit represented by each formula, the specific structure will be referred to as a "repeat unit structure." A specific structure is a structure obtained by assigning specific structures or numerical values to all the symbols in the general formula. That is, a polymer having an arylamine structure as a repeating unit has a repeating unit structure included in the above formula (54), a repeating unit structure included in the above formula (55), a repeating unit structure included in the above formula (56), Among the repeating unit structures contained in the above formula (57) and the repeating unit structure contained in the above formula (60), it may contain only one repeating unit structure, or it may contain two or more plural repeating unit structures. good. When two or more repeating unit structures are included, these two or more repeating units may be repeating unit structures included in the same general formula, or may be repeating unit structures included in different general formulas. There may be. From the viewpoint of charge transportability and durability, a polymer having an arylamine structure as a repeating unit is a polymer containing one or two specific repeating unit structures represented by each of these formulas and containing no other repeating unit structures. More preferably, it is a combination.

[Concrete example]
Specific examples of the above-mentioned polymers are shown below, but the above-mentioned polymers are not limited to these. Note that the numbers in the chemical formula represent the molar ratio of repeating units.
These polymers may be random copolymers, alternating copolymers, block copolymers, graft copolymers, or the like, and are not limited to the arrangement order of the monomers.

<Production method of polymer>
The method for producing the polymer contained in the composition of the present invention is not particularly limited and is arbitrary. Examples include a polymerization method using a Suzuki reaction, a polymerization method using a Grignard reaction, a polymerization method using a Yamamoto reaction, a polymerization method using an Ullmann reaction, a polymerization method using a Buchwald-Hartwig reaction, and the like. Moreover, it can be manufactured by a manufacturing method similar to the manufacturing method of the polymer described in International Publication No. 2019/177175, International Publication No. 2020/171190, and International Publication No. 2021/125011.

In the case of the polymerization method using the Ullmann reaction and the polymerization method using the Buchwald-Hartwig reaction, for example, a dihalogenated aryl represented by the following formula (2a) (Z represents a halogen atom such as I, Br, Cl, F, etc.) and the following By reacting with the primary aminoaryl represented by formula (2b), a polymer containing the repeating unit represented by formula (54) is synthesized.

(In the above reaction formula, Ar ⁵¹ , R ²⁰¹ , R ²⁰² , X, and a to d have the same meanings as in the above formula (54).)

In addition, in the case of the polymerization method using the Ullmann reaction and the polymerization method using the Buchwald-Hartwig reaction, for example, a dihalogenated aryl represented by the formula (3a) (Z represents a halogen atom such as I, Br, Cl, F, etc.) By reacting with the primary aminoaryl represented by formula (3b), a polymer containing the repeating unit represented by formula (55) is synthesized.

(In the above reaction formula, Ar ⁵¹ , R ³⁰³ to R ³⁰⁶ , n, m, l, p, and q have the same definitions as in the above formula (55).)

In the above polymerization method, the reaction for forming an N-aryl bond is usually carried out in the presence of a base such as potassium carbonate, sodium tert-butoxy, or triethylamine.
Further, it can also be carried out in the presence of a transition metal catalyst such as copper or palladium complex.

<Content of arylamine compound of the present invention>
From the viewpoint of reducing the injection barrier to the charge transport layer in the composition ratio of the solid components of the composition of the present invention, the content of the arylamine compound of the present invention is preferably 10% by weight or more, more preferably 25% by weight or more, More preferably 30% by weight or more. On the other hand, from the viewpoint of maintaining charge transport properties in the charge transport layer, the content of the arylamine compound of the present invention in the composition of the present invention is 99% by weight or less in terms of the composition ratio of the solid components of the composition. It is preferably 90% by weight or less, and even more preferably 80% by weight or less.

<Composition ratio/content of arylamine compound and electron-accepting compound in the composition>
In the composition of the present invention, the content of the arylamine compound of the present invention is preferably 99% by weight or less, and 97% by weight or less based on the total amount of the arylamine compound of the present invention and the electron-accepting compound of the present invention. % or less, more preferably 95% by weight or less. Further, it is preferably 50% by weight or more, more preferably 70% by weight or more, and even more preferably 80% by weight or more. Within these ranges, the film formed using the composition of the present invention is sufficiently crosslinked and insolubilized, and it is possible to directly wet-coat the film formed using the composition of the present invention. And, when a film formed using the composition of the present invention is used as a charge injection film, the injection barrier is reduced in the charge transport layer, resulting in excellent charge transport properties and improved stability during charge transport. It is believed that the durability of an element including a film formed using the composition of the present invention is improved.

<Content of charge transporting polymer compound>
In order to improve the charge transport properties of the film formed from the arylamine compound of the present invention and the electron-accepting compound of the present invention, these compounds are preferably used in combination with a charge transport polymer compound. In this case, the content of the charge-transporting polymer compound in the composition of the present invention may be 10% by weight or more in terms of the composition ratio of the solid components of the composition of the present invention, from the viewpoint of charge-transporting properties. The content is preferably 20% by weight or more, and more preferably 20% by weight or more. On the other hand, from the viewpoint of reducing the charge injection barrier between the charge injection layer and the charge transport layer adjacent to the charge injection layer, the content is preferably 95% by weight or less, more preferably 90% by weight or less, and 85% by weight or less. More preferably, it is less than % by weight.

[Composition]
The composition of the present invention may further contain a solvent, a polymerization initiator, an additive, and the like.

<Solvent>
Preferably, the composition of the present invention further contains a solvent. In particular, when forming a charge transport film by a wet film forming method using the composition of the present invention, a solvent is used to combine the arylamine compound of the present invention and the electron-accepting compound of the present invention, as well as the charge transport property. Preferably, the polymer compound is dissolved.

The solvent contained in the composition of the present invention may be any type of solvent as long as it is capable of dissolving both the arylamine compound of the present invention, the electron-accepting compound of the present invention, and the charge transporting polymer compound. is not particularly limited. Here, the solvent that dissolves the arylamine compound of the present invention and the electron-accepting compound of the present invention preferably contains the arylamine compound of the present invention at 0.005% by weight or more, more preferably at least 0.5% by weight, More preferably, it is a solvent that dissolves 1% by weight or more. Further, it is a solvent that dissolves the electron-accepting compound preferably at least 0.001% by weight, more preferably at least 0.1% by weight, even more preferably at least 0.2% by weight. Further, the solvent preferably dissolves the charge transporting polymer compound in an amount of 0.005% by weight or more, more preferably 0.5% by weight or more, and still more preferably 1% by weight or more.

Preferred solvents include, for example, aromatic hydrocarbon solvents, ether solvents, and ester solvents.
Specifically, examples of the aromatic hydrocarbon solvent include toluene, xylene, mesitylene, tetralin, and cyclohexylbenzene.
Examples of ether solvents 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. , phenethol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and other aromatic ethers.
Examples of ester solvents include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and benzoic acid. Examples include aromatic esters such as n-butyl.
Any one of these may be used alone, or two or more may be used in any combination and ratio.

Examples of solvents that can be used in addition to the above-mentioned ether solvents and ester solvents include amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide, dimethyl sulfoxide, and the like. Any one of these may be used alone, or two or more may be used in any combination and ratio. Furthermore, one or more of these solvents may be used in combination with one or more of the above-mentioned ether solvents and ester solvents. In particular, aromatic hydrocarbon solvents such as benzene, toluene, and xylene have a low ability to dissolve electron-accepting compounds and free carriers (cation radicals), so they cannot be used in combination with ether solvents and ester solvents. preferable.

When a solvent is used, the concentration of the solvent in the composition of the present invention is preferably 10% by weight or more, more preferably 30% by weight or more, and even more preferably 50% by weight or more. Further, the concentration of the solvent in the composition is preferably 99.999% by weight or less, more preferably 99.99% by weight or less, still more preferably 99.9% by weight or less. In addition, when using a mixture of two or more types of solvents, the total of these solvents should satisfy this range.

Note that when the composition of the present invention is used in an organic electroluminescent device, each layer is required to be uniform because the organic electroluminescent device is formed by laminating layers made of a large number of organic compounds. . When forming layers using a wet film formation method, if water is present in the solution (composition) for thin film formation, water will be mixed into the coating film and the uniformity of the film will be impaired. Therefore, the water content in the solution should be kept as low as possible. Less is better. Further, since organic electroluminescent devices generally use many materials such as cathodes that are significantly degraded by moisture, the presence of moisture is undesirable from the viewpoint of device deterioration.

Specifically, the amount of water contained in the composition of the present invention is preferably suppressed to 1% by weight or less, particularly 0.1% by weight or less, and more preferably 0.05% by weight or less.
Examples of methods for reducing the amount of water in the composition include nitrogen gas blanketing, use of a desiccant, dehydration of the solvent in advance, and use of a solvent with low water solubility. Among these, from the viewpoint of preventing the solution coating film from absorbing moisture in the atmosphere and whitening during the coating process, it is preferable to use a solvent with low water solubility.
When used for film formation by a wet film formation method, the composition of the present invention is preferably used in a solvent in which the solubility of water is low, specifically, the solubility of water at 25° C. is 1% by weight or less, preferably 0.1% by weight. % or less, preferably at a concentration of 10% by weight or more, especially 30% by weight or more, especially 50% by weight or more, based on the entire composition.

<Composition for charge transport film>
When the electron-accepting compound having a crosslinking group is the electron-accepting ionic compound described above, the electron-accepting ionic compound and the cross-linking group represented by any of the formulas (3-1) to (3-4) above. (hereinafter appropriately referred to as "composition for charge transport film (A)"), or a cation radical of an arylamine compound having a crosslinking group described below and the electron-accepting ion. It is preferable to use the composition as a composition containing a charge transporting ionic compound comprising a counter anion which is a part of the compound (hereinafter referred to as "composition for charge transport film (B)"). Here, for convenience, the composition for a charge transport film (A) and the composition for a charge transport film (B) will be explained separately. It also includes a composition containing an arylamine compound having a group and a charge-transporting ionic compound consisting of a cation radical of the arylamine compound having a crosslinking group described below and a counter anion that is part of the electron-accepting ionic compound.

Note that the charge transport film compositions (A) and (B) are compositions (compositions for charge transport materials) that can be widely used for charge transport materials. However, since this is usually formed into a film and used as a hole injection layer and/or a hole transport layer, that is, as a "charge transport film" that transports holes, which are charges, in this specification, the term "charge transport film" is particularly used. ``composition for use''.

<Composition for charge transport film (A)>
The charge transport film composition (A) includes the arylamine compound having the crosslinking group, the electron-accepting compound having the crosslinking group, and a solvent. The arylamine compound having a crosslinking group may be used singly or in combination of two or more. Furthermore, the hole transporting polymer compound may be contained.

<Preparation method of charge transport film composition (A)>
The charge transport film composition (A) is prepared by mixing at least the electron-accepting compound of the present invention and the arylamine compound of the present invention. At this time, the charge transport film composition (A) preferably contains a solvent, and the electron-accepting compound of the present invention and the arylamine compound of the present invention are preferably dissolved in the solvent and mixed.

The content of the electron-accepting compound of the present invention in the charge transport film composition (A) is usually 0.1% by weight or more, preferably 1% by weight or more, based on the arylamine compound of the present invention. , usually 100% by weight or less, preferably 40% by weight or less. If the content of the electron-accepting compound is at least the above-mentioned lower limit, free carriers (cation radicals of the arylamine compound of the present invention) can be sufficiently generated, and preferably, when the content is at least the above-mentioned upper limit, sufficient charge transport ability can be ensured. It's good to be able to do it. When two or more types of electron-accepting compounds are used together, the total content thereof should be within the above range. The same applies to charge transporting compounds.

<Composition for charge transport film (B)>
As described above, the charge transporting film composition (B) is a composition containing a charge transporting ionic compound consisting of a cation radical of the arylamine compound of the present invention and a counter anion of the electron accepting ionic compound. It is.
The cation radical of the arylamine compound of the present invention, which is a cation of the charge transporting ionic compound, is a chemical species obtained by removing one electron from the electrically neutral compound shown in the arylamine compound of the present invention.
The cation radical of the arylamine compound of the present invention is an aromatic arylamine compound having a structure represented by the following formulas (300-1) to (300-4).

In the above formulas (300-1) to (300-4), Ar ² , Ar ³ , R ² , A ² and a ² are respectively Ar ² and Ar in the above formulas (3-1) to (3-4). ³ , R ² , A ² , and a ² .

Formulas (300-1) to (300-4) are preferably aromatic arylamine compounds having structures represented by the following formulas (310-1) to (310-4), respectively. This is preferable because it has a redox potential and a stable charge-transporting ionic compound can be obtained.

In the above formulas (310-1) to (310-4), Ar ² , Ar ³ , R ² , A ² and a ² are respectively Ar ² and Ar in the above formulas (3-1) to (3-4). ³ , R ² , A ² , and a ² . Ar ⁴ is a residue obtained by removing the phenylene group from Ar ² in the above formulas (300-1) to (300-4) when Ar ² has a structure capable of bonding to the arylamine structure via phenylene.

<Charge transporting ionic compound>
The charge-transporting ionic compound is a compound in which the cation radical of the arylamine compound of the present invention and a counter anion that is part of the electron-accepting ionic compound are ionically bonded.
The charge-transporting ionic compound can be obtained by mixing an electron-accepting ionic compound and the arylamine compound of the present invention, and is easily dissolved in various solvents. Specifically, it can be obtained by the method described in <Preparation method of charge transport film composition (B)> below.
The molecular weight of the charge-transporting ionic compound is usually 1,000 or more, preferably 1,100 or more, more preferably 1,200 or more, and usually 9,000 or less, preferably 5,000 or less, even more preferably is in the range of 4000 or less.

<Preparation method of charge transport film composition (B)>
The charge-transporting ionic compound (B) is preferably prepared by dissolving and mixing an electron-accepting ionic compound and the arylamine compound of the present invention in a solvent. In this solution, the arylamine compound of the present invention is oxidized by the electron-accepting ionic compound to form a cation radical, and an ionic compound of the counter anion of the electron-accepting ionic compound and the cation radical of the arylamine compound of the present invention is formed. A charge transporting ionic compound is produced.

At this time, by mixing the arylamine compound of the present invention and an electron-accepting ionic compound in a solution, the arylamine compound of the present invention has electron-accepting properties near the nitrogen atom of the arylamine, which is a site that is easily oxidized. The probability that the ionic compound exists increases, and the amine structure of the arylamine compound of the present invention is oxidized by the electron-accepting ionic compound to become a cation radical, and the counter anion of the electron-accepting ionic compound and the arylamine of the present invention This is because an ionic compound with the cation radical of the compound is likely to be formed. At this time, it is preferable to heat the solution from the viewpoint of promoting the reaction.

It is also preferable to prepare the mixture by heating a mixture of an electron-accepting ionic compound and the arylamine compound of the present invention. This mixture is preferably a film formed by coating and drying a solution in which a mixture of an electron-accepting ion compound and the arylamine compound of the present invention is dissolved in a solvent. By heating the mixture, the electron-accepting ionic compound and the arylamine compound of the present invention diffuse into each other in the mixture, and the arylamine compound of the present invention is near the nitrogen atom of the amine structure, which is a site that is easily oxidized. This is because the probability that an electron-accepting compound exists increases, and an ionic compound of the counter anion of the electron-accepting ionic compound and the cation radical of the arylamine compound of the present invention is likely to be generated. The heating temperature at this time is preferably a temperature at which the crosslinking groups of the composition do not undergo a crosslinking reaction, but even if the temperature is such that the crosslinking groups undergo a crosslinking reaction, the crosslinking reaction also occurs while diffusing, so there is no problem with the electron-accepting ionic compound. It is formed.

The charge transport film composition (B) may contain one type of charge transporting ionic compound described above, or may contain two or more types. It is preferable to contain one or two types of charge-transporting ionic compounds, and it is more preferable to contain only one type of charge-transporting ionic compound. This is because there is little variation in the ionization potential of the charge-transporting ionic compound and the hole-transporting property is excellent.
A composition containing one or two charge-transporting ionic compounds refers to a composition prepared using only two or three electron-accepting ionic compounds and the arylamine compound of the present invention in total. A composition prepared using at least one electron-accepting ionic compound and at least one arylamine compound of the present invention.

It is also preferable that the charge transporting film composition (B) contains a charge transporting compound in addition to the charge transporting ionic compound. As the charge-transporting compound, a polymer containing the above-mentioned arylamine structure as a repeating unit, which is the above-mentioned hole-transporting polymer compound, is particularly preferable. When preparing the charge transport film composition (B), the content of the arylamine compound of the present invention as a charging amount is preferably 10% by weight or more, more preferably 20% by weight based on the charge transporting ionic compound. It is at least 30% by weight, more preferably at least 30% by weight, and is preferably at most 10,000% by weight, even more preferably at most 1,000% by weight.

The charge transport film formed from the charge transport film composition (B) has high hole injection/transport ability due to the movement of positive charges from the charge transport ionic compound to the nearby neutral charge transport compound. Therefore, it is preferable that the charge transporting ionic compound and the neutral arylamine compound of the present invention have a mass ratio of about 1:100 to 100:1, and a mass ratio of about 1:20 to 20:1. More preferably, it is a ratio.

<Relationship between charge transport film compositions (A) and (B)>
The charge transport film formed from the charge transport film composition (A) has excellent heat resistance and high hole injection/transport ability. The reason why such excellent characteristics can be obtained will be explained below.
The charge transport film composition (A) contains the above-described electron-accepting compound and charge-transporting compound. The cation in the electron-accepting ionic compound has a hypervalent central atom and its positive charge is widely delocalized, so it has high electron-accepting properties. As a result, electron transfer occurs from the charge-transporting compound to the cation of the electron-accepting ionic compound, and a charge-transporting ionic compound consisting of the cation radical of the charge-transporting compound and the counter anion is generated. Since the cation radicals of this charge transporting compound serve as charge carriers, the electrical conductivity of the charge transporting film can be increased. That is, when the charge transporting film composition (A) is prepared, it is considered that a charge transporting ionic compound, which is at least partially composed of the cation radical of the charge transporting compound and the counter anion of the electron accepting ionic compound, is generated.
For example, when electron transfer occurs from the charge transporting compound represented by formula (7) below to the electron accepting compound represented by formula (6), the charge transporting compound represented by formula (9) A charge transporting ionic compound consisting of a cation radical and a counter anion is generated.

[Preparation of composition]
The composition of the present invention is prepared by mixing a functional material containing the arylamine compound of the present invention, the electron-accepting compound of the present invention, preferably the above-mentioned electron-accepting compound, and a solvent, and dissolving or dissolving the mixture by heating for a certain period of time. It can be prepared by dispersing it. In order to uniformly dissolve or disperse the functional material in the solvent, the heating temperature is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, for example 100 to 115°C. Further, the heating time is preferably 30 minutes or more, more preferably 45 minutes or more, and even more preferably 60 minutes or more, for example 60 to 180 minutes.

The heated composition is filtered using a membrane filter, depth filter, etc. to remove coarse particles before use. Considering that the composition is applied by ejection from a nozzle of an inkjet head, the pore diameter of the filter is preferably 0.5 μm or less, more preferably 0.2 μm or less, and even more preferably 0.1 μm or less.

[Film forming method using composition]
When forming a film using the composition of the present invention, the composition of the present invention is preferably a solution containing a solvent, and the composition of the present invention is preferably formed into a wet film.
The wet film forming method refers to a method in which a composition containing a solvent is applied onto a substrate, and the solvent is dried and removed to form a film. The coating method is not particularly limited, but includes, 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, a capillary coating method, an inkjet method, a screen printing method, Examples include gravure printing method and flexographic printing method.

As a method for removing the solvent by drying, heating drying is usually performed. Examples of heating means used in the heating step include a clean oven, a hot plate, and infrared heating.
As the infrared heating, a halogen heater, a ceramic coated halogen heater, a ceramic heater, etc. can be used.
Heating with infrared rays applies thermal energy directly to the substrate or film, so it can dry in a shorter time than heating using an oven or hot plate. Therefore, the influence of gases (moisture and oxygen) in the heating atmosphere and the influence of minute dust can be minimized, which improves productivity, which is preferable.

The heating temperature is usually 80°C or higher, preferably 100°C or higher, and more preferably 150°C or higher. Further, the heating temperature is usually 300°C or lower, preferably 280°C or lower, and more preferably 260°C or lower.
The heating time is usually 10 seconds or more, preferably 60 seconds or more, more preferably 90 seconds or more, and usually 120 minutes or less, preferably 60 minutes or less, more preferably 30 minutes or less.
Moreover, it is also preferable to perform vacuum drying before heat drying.
The thickness of the organic layer formed using the composition of the present invention by a wet film forming method is usually 5 nm or more, preferably 10 nm or more, and more preferably 20 nm or more. Further, the film thickness is usually 1000 nm or less, preferably 500 nm or less, and more preferably 300 nm or less.

[Organic electroluminescent device]
The organic electroluminescent device of the present invention is an organic electroluminescent device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, wherein the organic layer is formed using the composition of the present invention. can be formed. Moreover, the organic electroluminescent device of the present invention may be manufactured by the method for manufacturing an organic electroluminescent device described below.
A film using the composition of the present invention and a film formed using the composition of the present invention can be suitably used as a charge transport layer. This charge transport layer is particularly preferably used as a charge transport film of an organic electroluminescent device.

In one embodiment, the organic electroluminescent device of the present invention is an organic electroluminescent device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer having the above formula ( Contains a crosslinking reaction product of an arylamine compound represented by any one of 3-1) to (3-4) and an electron-accepting compound represented by the above formula (81).

In another aspect, the organic electroluminescent device of the present invention is an organic electroluminescent device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, wherein the organic layer is as described above. An arylamine compound represented by any one of formulas (3-1) to (3-4) and an arylamine structure represented by the above formula (50) as repeating units, and a crosslinking group. Contains a crosslinking reaction product with a polymer.

As an example of the structure of the organic electroluminescent device of the present invention, FIG. 1 shows a schematic diagram (cross section) of a structural example of an organic electroluminescent device 8. In FIG. 1, 1 represents a substrate, 2 an anode, 3 a hole injection layer, 4 a hole transport layer, 5 a light emitting layer, 6 an electron transport layer, and 7 a cathode.

[substrate]
The substrate 1 serves as a support for the organic electroluminescent element, and typically includes a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like. Among these, glass plates and plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. The substrate is preferably made of a material with high gas barrier properties, since deterioration of the organic electroluminescent element by outside air is unlikely to occur. For this reason, especially when using a material with low gas barrier properties such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve the gas barrier properties.

[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 made of metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as indium and/or tin oxides; metal halides 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 evaporation method. In addition, 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., it is necessary to add a suitable binder resin solution to the anode. It can also be formed by dispersing it and coating it on the substrate. In the case of conductive polymers, it is also possible to form a thin film directly on the substrate by electrolytic polymerization, or to form an anode by coating 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 of the anode.

The thickness of the anode 2 may be determined depending on the required transparency, material, etc. When particularly high transparency is required, the thickness is preferably such that the visible light transmittance is 60% or more, and the thickness is more preferably such that the visible light transmittance is 80% or more. 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, if transparency is not required, the thickness of the anode 2 may be set arbitrarily depending on the required strength, etc. In this case, the anode 2 may have the same thickness as the substrate.

When forming another layer on the surface of the anode 2, impurities on the anode 2 are removed and its ionization potential is It is preferable to adjust the hole injection property to improve the hole injection property.

[Hole injection layer]
A layer that has the 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 the function of transporting holes from the anode 2 side to the light emitting layer 5 side, 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 because it enhances the function of transporting holes from the anode 2 to the light emitting layer 5 side. When forming the hole injection layer 3, the hole injection layer 3 is usually formed on the anode 2.

The hole injection layer 3 formed using the composition of the present invention contains a crosslinking reaction product of the arylamine compound of the present invention and the electron-accepting compound of the present invention.

The method for forming the hole injection layer 3 is not particularly limited, and examples thereof include a vacuum evaporation method, a wet film formation method, and the like.
In the case of layer formation by a wet film formation method, the composition of the present invention is prepared, coated on the anode 2 by a wet film formation method such as a spin coating method or a dip coating method, and dried to form a hole injection layer 3. to form.

Particularly preferably, a composition comprising the arylamine compound of the present invention and the electron-accepting compound of the present invention is used, and the arylamine compound of the present invention and the electron-accepting compound of the present invention are particularly preferably used. The method is to use a film formed using a composition containing a chemical compound.
The thickness of the hole injection layer 3 formed in this way is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

The hole injection layer may be formed by a vacuum evaporation method or a wet film formation method. In terms of excellent film-forming properties, it is preferable to form the film by a wet film-forming method.
Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents.

Examples of ether solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), and 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and anisole. , phenethol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and other aromatic ethers.

Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, methylnaphthalene, etc. It will be done.

Examples of the amide solvent include N,N-dimethylformamide and N,N-dimethylacetamide.

In addition to these, dimethyl sulfoxide and the like can also be used.

Formation of the hole injection layer 3 by a wet film forming method is usually performed by preparing a composition for forming the hole injection layer, and then applying it on a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2). This is done by coating and drying.

After forming the hole injection layer 3, the coating film is usually dried by heating, vacuum drying, or the like.

[Hole transport layer]
The hole transport layer 4 is a layer that has the function of transporting holes from the anode 2 side to the light emitting layer 5 side. Although the hole transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, it is preferable to form this layer in terms of strengthening the function of transporting holes from the anode 2 to the light emitting layer 5. . When forming the hole transport layer 4, the hole transport layer 4 is usually formed between the anode 2 and the light emitting layer 5. Further, if the hole injection layer 3 described above is present, it is formed between the hole injection layer 3 and the light emitting layer 5.

The film thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and on the other hand, usually 300 nm or less, preferably 100 nm or less.

The material forming the hole transport layer 4 is preferably a material that has high hole transport properties and can efficiently transport injected holes. For this purpose, it is preferable that the ionization potential is low, the transparency to visible light is high, the hole mobility is high, the stability is excellent, and impurities that become traps are hardly generated during production or use. In addition, in many cases, the hole transport layer 4 is in contact with the light-emitting layer 5, so it does not quench the light emitted from the light-emitting layer 5 or form an exciplex with the light-emitting layer 5, thereby reducing efficiency. It is preferable.

The material for the hole transport layer 4 may be any material that has been conventionally used as a constituent material of the hole transport layer, for example, the hole transport material used for the hole injection layer 3 described above. Examples of the compounds include those listed above. In addition, arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, fused polycyclic aromatic Examples include group derivatives, metal complexes, and the like.

Further, for example, polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ether sulfone derivatives containing tetraphenylbenzidine, polyarylene vinylene derivatives, polysiloxane derivatives, polythiophene derivatives, poly(p-phenylene vinylene) derivatives, and the like. These may be alternating copolymers, random polymers, block polymers or graft copolymers. It may also be a polymer whose main chain is branched and has three or more terminal parts, or a so-called dendrimer.

Among these, polyarylamine derivatives and polyarylene derivatives are preferred.
As the polyarylamine derivative, a polymer containing a repeating unit represented by the following formula (I) is preferable. In particular, a polymer consisting of repeating units represented by the following formula (I) is preferred, and in this case, Ar ^a ′ or Ar ^b ′ may be different in each repeating unit.

(In formula (I), Ar ^a ' and Ar ^b ' are each independently an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent) )

Examples of polyarylene derivatives include polymers having an arylene group in its repeating unit, such as an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent. .

As the polyarylene derivative, a polymer having a repeating unit consisting of the following formula (II-1) and/or the following formula (II-2) is preferable.

(In formula (II-1), R ^a , R ^b , R ^c and R ^d are each independently an alkyl group, an alkoxy group, a phenylalkyl group, a phenylalkoxy group, a phenyl group, a phenoxy group, an alkylphenyl group, It represents an alkoxyphenyl group, an alkylcarbonyl group, an alkoxycarbonyl group, or a carboxy group. x11 and x12 each independently represent an integer of 0 to 3. When x11 or x12 is 2 or more, the plurality contained in one molecule R ^a or R ^b may be the same or different, and adjacent R ^a or R ^b may form a ring.)

(In formula (II-2), R ^e and R ^f are each independently synonymous with R ^a , R ^b , R ^c or R ^d in the above formula (II-1). x13 and x14 are each independently represents an integer from 0 to 3. When x13 or x14 is 2 or more, multiple R ^e and R ^f contained in one molecule may be the same or different, and adjacent R ^e or R ^f may form a ring with each other. L represents an atom or atomic group constituting a 5-membered ring or a 6-membered ring.)

Specific examples of L include an oxygen atom, a boron atom that may have a substituent, a nitrogen atom that may have a substituent, a silicon atom that may have a substituent, and a boron atom that may have a substituent. A phosphorus atom which may have a substituent, a sulfur atom which may have a substituent, a carbon atom which may have a substituent, or a group formed by bonding these.

In addition, the polyarylene derivative may have a repeating unit represented by the following formula (III-3) in addition to the repeating unit represented by the above formula (II-1) and/or the above formula (II-2). is preferred.

(In formula (III-3), Ar ^c to Ar ⁱ each independently represent an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent. x15 and x16 each independently represent 0 or 1.)

Specific examples of the above formulas (III-1) to (III-3) and polyarylene derivatives include those described in Japanese Patent Application Publication No. 2008-98619.

When forming the hole transport layer 4 by a wet film formation method, a composition for forming a hole transport layer is prepared in the same manner as in the formation of the hole injection layer 3 described above, and then heated and dried after wet film formation. .

The composition for forming a hole transport layer contains a solvent in addition to the hole transport compound described above. The solvent used is the same as that used for the hole injection layer forming composition. Further, the film forming conditions, heating drying conditions, etc. are the same as those for forming the hole injection layer 3.

When forming the hole transport layer by vacuum evaporation, the film forming conditions are the same as those for forming the hole injection layer 3 described above.

In addition to the above-mentioned hole-transporting compound, the hole-transporting layer 4 may contain various light-emitting materials, electron-transporting compounds, binder resins, coatability improvers, and the like.

Additionally, the hole transport layer 4 may be a layer formed by crosslinking a crosslinkable compound. The crosslinkable compound is a compound having a crosslinkable group, and forms a network polymer compound by crosslinking.

Examples of crosslinking groups include groups derived from cyclic ethers such as oxetane and epoxy; groups derived from unsaturated double bonds such as vinyl, trifluorovinyl, styryl, acrylic, methacryloyl, and cinnamoyl; Examples include groups derived from cyclobutene.

The crosslinkable compound may be a monomer, oligomer, or polymer. The crosslinkable compound may contain only one type, or may contain two or more types 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 those listed above, and examples of cross-linking compounds include compounds in which a cross-linking group is bonded to the main chain or side chain of these hole-transporting compounds. It will be done. In particular, the crosslinkable group is preferably bonded to the main chain via a linking group such as an alkylene group. In addition, particularly as the hole-transporting compound, a polymer containing a repeating unit having a crosslinkable group is preferable, and the crosslinkable group is present in the formula (I) or formulas (II-1) to (III-3). is preferably a polymer having repeating units bonded directly or via a linking group.

In order to form the hole transport layer 4 by crosslinking a crosslinkable compound, a composition for forming a hole transport layer is usually prepared by dissolving or dispersing the crosslinkable compound in a solvent, and the film is formed by wet film formation. to crosslink.

The film thickness of the hole transport layer 4 formed in this way is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 150 nm or less.

[Light-emitting layer]
The light-emitting layer 5 is a layer that is excited by recombining holes injected from the anode 2 and electrons injected from the cathode 7 when an electric field is applied between a pair of electrodes, and has the function of emitting light. .
The light emitting layer 5 is a layer formed between the anode 2 and the cathode 7, and if there is a hole injection layer on the anode, the light emitting layer is formed between the hole injection layer and the cathode, and the light emitting layer is a layer formed between the anode 2 and the cathode. If there is a hole transport layer on top of the hole transport layer, it is formed between the hole transport layer and the cathode.
As described above, the organic electroluminescent device of the present invention preferably contains a light-emitting layer forming material suitable for the light-emitting layer.

The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention, but a thicker layer is preferable because defects are less likely to occur in the layer, and a thinner layer is preferable because it is easier to lower the driving voltage. . For this reason, it is preferably 3 nm or more, more preferably 5 nm or more, and on the other hand, it is usually preferably 200 nm or less, and even more preferably 100 nm or less.

The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material), and preferably contains one or more host materials.

[Suitable luminescent layer forming material]
The light emitting layer of the present invention includes a light emitting material and a charge transporting material. The luminescent material may be a phosphorescent material or a fluorescent material. Charge Transport Film Preferably, the red emissive material and the green emissive material are phosphorescent emissive materials, and the blue emissive material is a fluorescent emissive material.

<Phosphorescent material>
A phosphorescent material refers to a material that emits light from an excited triplet state. For example, a typical example is a metal complex compound containing Ir, Pt, Eu, etc., and the structure of the material preferably includes a metal complex.

Among metal complexes, phosphorescent organometallic complexes that emit light via the triplet state are known from the long period periodic table (hereinafter, unless otherwise specified, when we refer to the periodic table, we refer to the long period periodic table). ) Examples include Werner type complexes or organometallic complexes containing a metal selected from Groups 7 to 11 as a central metal. Examples of such phosphorescent materials include phosphorescent materials described in International Publication No. 2014/024889, International Publication No. 2015/087961, International Publication No. 2016/194784, and Japanese Patent Application Publication No. 2014-074000. can be mentioned. Preferably, a compound represented by the following formula (201) or a compound represented by the following formula (205) is preferable, and a compound represented by the following formula (201) is more preferable.

In formula (201), ring A1 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent.
Ring A2 represents an aromatic heterocyclic structure which may have a substituent.
R ¹⁰¹ and R ¹⁰² are each independently a structure represented by formula (202), and "*" represents the bonding position with ring A1 or ring A2. R ¹⁰¹ and R ¹⁰² may be the same or different, and when a plurality of R ¹⁰¹ and R ¹⁰² exist, they may be the same or different.

Ar ²⁰¹ and Ar ²⁰³ each independently represent an aromatic hydrocarbon ring structure that may have a substituent or an aromatic heterocyclic structure that may have a substituent.
Ar ²⁰² is an aromatic hydrocarbon ring structure that may have a substituent, an aromatic heterocyclic structure that may have a substituent, or an aliphatic hydrocarbon structure that may have a substituent. represents.
Substituents bonded to ring A1, substituents bonded to ring A2, or substituents bonded to ring A1 and substituents bonded to ring A2 may bond to each other to form a ring.

B ²⁰¹ -L ²⁰⁰ -B ²⁰² represents an anionic bidentate ligand. B ²⁰¹ and B ²⁰² each independently represent a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms constituting a ring. L ²⁰⁰ represents a single bond or an atomic group that constitutes a bidentate ligand together with B ²⁰¹ and B ²⁰² . When a plurality of B ²⁰¹ -L ²⁰⁰ -B ²⁰² exist, they may be the same or different.

Note that in equations (201) and (202),
i1 and i2 each independently represent an integer between 0 and 12,
i3 represents an integer of 0 or more with an upper limit of the number that can be replaced with Ar ²⁰² ,
i4 represents an integer of 0 or more with an upper limit of the number that can be replaced with Ar ²⁰¹ ,
k1 and k2 each independently represent an integer of 0 or more with an upper limit of the number that can be substituted in ring A1 and ring A2,
z represents an integer from 1 to 3.

(substituent)
Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

<Substituent group S>
・Alkyl group, preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably an alkyl group having 1 to 6 carbon atoms .
-Alkoxy group, preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, still more preferably an alkoxy group having 1 to 6 carbon atoms.
-Aryloxy group, preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, even more preferably an aryloxy group having 6 to 12 carbon atoms, particularly preferably an aryloxy group having 6 to 12 carbon atoms Aryloxy group.
- Heteroaryloxy group, preferably a heteroaryloxy group having 3 to 20 carbon atoms, more preferably a heteroaryloxy group having 3 to 12 carbon atoms.
- An alkylamino group, preferably an alkylamino group having 1 to 20 carbon atoms, more preferably an alkylamino group having 1 to 12 carbon atoms.
- An arylamino group, preferably an arylamino group having 6 to 36 carbon atoms, more preferably an arylamino group having 6 to 24 carbon atoms.
-Aralkyl group, preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, even more preferably an aralkyl group having 7 to 12 carbon atoms.
- Heteroaralkyl group, preferably a heteroaralkyl group having 7 to 40 carbon atoms, more preferably a heteroaralkyl group having 7 to 18 carbon atoms.
・Alkenyl group, preferably an alkenyl group having 2 to 20 carbon atoms, more preferably an alkenyl group having 2 to 12 carbon atoms, still more preferably an alkenyl group having 2 to 8 carbon atoms, particularly preferably an alkenyl group having 2 to 6 carbon atoms .
- An alkynyl group, preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 12 carbon atoms.
-Aryl group, preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, still more preferably an aryl group having 6 to 18 carbon atoms, particularly preferably an aryl group having 6 to 14 carbon atoms .
・Heteroaryl group, preferably a heteroaryl group having 3 to 30 carbon atoms, more preferably a heteroaryl group having 3 to 24 carbon atoms, still more preferably a heteroaryl group having 3 to 18 carbon atoms, particularly preferably a heteroaryl group having 3 to 30 carbon atoms 14 heteroaryl groups.
- An alkylsilyl group, preferably an alkylsilyl group in which the alkyl group has 1 to 20 carbon atoms, more preferably an alkylsilyl group in which the alkyl group has 1 to 12 carbon atoms.
- An arylsilyl group, preferably an arylsilyl group in which the aryl group has 6 to 20 carbon atoms, more preferably an arylsilyl group in which the aryl group has 6 to 14 carbon atoms.
- An alkylcarbonyl group, preferably an alkylcarbonyl group having 2 to 20 carbon atoms.
-Arylcarbonyl group, preferably an arylcarbonyl group having 7 to 20 carbon atoms.

In the above groups, one or more hydrogen atoms may be replaced with a fluorine atom, or one or more hydrogen atoms may be replaced with a deuterium atom.
Unless otherwise specified, aryl is an aromatic hydrocarbon ring and heteroaryl is an aromatic heterocycle.
- Hydrogen atom, deuterium atom, fluorine atom, cyano group, or -SF ₅ .

Among the substituent group S, preferred are alkyl groups, alkoxy groups, aryloxy groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkylsilyl groups, arylsilyl groups, and groups thereof. is a group in which one or more hydrogen atoms of is replaced with a fluorine atom, a fluorine atom, a cyano group, or _-SF5 ,
More preferred are alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, and heteroaryl groups, and groups in which one or more hydrogen atoms of these groups are replaced with fluorine atoms, fluorine atoms, cyano group, or _-SF5 ,
More preferred are alkyl groups, alkoxy groups, aryloxy groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkylsilyl groups, and arylsilyl groups,
Particularly preferred are alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, and heteroaryl groups,
Most preferred are alkyl groups, arylamino groups, aralkyl groups, aryl groups, and heteroaryl groups.

These substituent group S may further have a substituent selected from substituent group S as a substituent. Preferable groups, more preferable groups, still more preferable groups, particularly preferable groups, and most preferable groups of the substituents that may be present are the same as the preferable groups in substituent group S.

(Ring A1)
Ring A1 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent.

The aromatic hydrocarbon ring is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring are preferred.

The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. More preferred are a furan ring, a benzofuran ring, a thiophene ring, and a benzothiophene ring.
Ring A1 is more preferably a benzene ring, a naphthalene ring, or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

(Ring A2)
Ring A2 represents an aromatic heterocyclic structure which may have a substituent.
The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specifically, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring, benzoxazole ring, benzimidazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, Examples include naphthyridine ring and phenanthridine ring, preferably pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring, and more preferably is a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, or a quinazoline ring, most preferably a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, a quinoxaline ring, or a quinazoline ring. .

(Combination of ring A1 and ring A2)
Preferred combinations of ring A1 and ring A2, expressed as (ring A1-ring A2), are (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring- (quinazoline ring), (benzene ring-benzothiazole ring), (benzene ring-imidazole ring), (benzene ring-pyrrole ring), (benzene ring-diazole ring), and (benzene ring-thiophene ring).

(Substituents on ring A1 and ring A2)
The substituents that ring A1 and ring A2 may have can be arbitrarily selected, but are preferably one or more substituents selected from the above substituent group S.

(Ar ²⁰¹ , Ar ²⁰² , Ar ²⁰³ )
Ar ²⁰¹ and Ar ²⁰³ each independently represent an aromatic hydrocarbon ring structure that may have a substituent or an aromatic heterocyclic structure that may have a substituent.
Ar ²⁰² is an aromatic hydrocarbon ring structure that may have a substituent, an aromatic heterocyclic structure that may have a substituent, or an aliphatic hydrocarbon structure that may have a substituent. represents.

When any of Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ is an aromatic hydrocarbon ring structure which may have a substituent, the aromatic hydrocarbon ring structure is preferably an aromatic hydrocarbon ring structure having 6 to 30 carbon atoms. It is a group hydrocarbon ring. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring are preferred, a benzene ring, a naphthalene ring, and a fluorene ring are more preferred, and a benzene ring is most preferred.

When either Ar ²⁰¹ or Ar ²⁰² is a benzene ring which may have a substituent, it is preferable that at least one benzene ring is bonded to an adjacent structure at the ortho or meta position, and at least one More preferably, two benzene rings are bonded to adjacent structures at meta positions.

When any of Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ is a fluorene ring that may have a substituent, the 9- and 9'-positions of the fluorene ring have a substituent or are bonded to adjacent structures. It is preferable that

When any of Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ is an aromatic heterocyclic structure which may have a substituent, the aromatic heterocyclic structure preferably contains a nitrogen atom, an oxygen atom, or An aromatic heterocycle having 3 to 30 carbon atoms and containing any sulfur atom, specifically a pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring , a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, a phenanthridine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring, preferably a pyridine ring or a pyrimidine ring. , triazine ring, carbazole ring, dibenzofuran ring, and dibenzothiophene ring.

When any of Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ is a carbazole ring which may have a substituent, the N-position of the carbazole ring may have a substituent or be bonded to an adjacent structure. preferable.

When Ar ²⁰² is an aliphatic hydrocarbon structure that may have a substituent, it is an aliphatic hydrocarbon structure having a linear, branched, or cyclic structure, and preferably has 1 to 24 carbon atoms. More preferably, the number of carbon atoms is 1 or more and 12 or less, and more preferably 1 or more and 8 or less.

(i1, i2, i3, i4, k1, k2)
i1 and i2 each independently represent an integer of 0 to 12, preferably 1 to 12, more preferably 1 to 8, and even more preferably 1 to 6. By being within this range, it is expected that solubility and charge transport properties will be improved.
i3 preferably represents an integer of 0 to 5, more preferably 0 to 2, more preferably 0 or 1.
i4 preferably represents an integer of 0 to 2, more preferably 0 or 1.
k1 and k2 each independently preferably represent an integer of 0 to 3, more preferably 1 to 3, more preferably 1 or 2, particularly preferably 1.

(Preferred substituents for Ar ²⁰¹ , Ar ²⁰² , Ar ²⁰³ )
The substituents that Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ may have can be arbitrarily selected, but are preferably one or more substituents selected from the above substituent group S, and preferred groups are also the above substituents. As shown in group S, more preferred are unsubstituted (hydrogen atoms), alkyl groups, and aryl groups, particularly preferred are unsubstituted (hydrogen atoms), alkyl groups, and most preferred are unsubstituted (hydrogen atoms). ) or a tert-butyl group, where the tert-butyl group is substituted by Ar ²⁰³ when Ar ²⁰³ is present, Ar ²⁰² when Ar ²⁰³ is absent, and Ar ²⁰¹ when Ar ²⁰² and Ar ²⁰³ are absent. It is preferable that you do so.

(Preferred embodiment of the compound represented by formula (201))
The compound represented by formula (201) is preferably a compound that satisfies any one or more of the following (I) to (IV).

(I) Phenylene linked formula The structure represented by formula (202) is a structure having a group in which benzene rings are linked, that is, a benzene ring structure, i1 is 1 to 6, and at least one benzene ring is in the ortho or meta position. It is preferable that the structure is bonded to an adjacent structure at the position.
Such a structure is expected to improve solubility and charge transport properties.

(II) (phenylene)-aralkyl (alkyl)
A structure having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or an aralkyl group is bonded to ring A1 or ring A2, that is, Ar ²⁰¹ is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, and i1 is 1 ~6, Ar ²⁰² is an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, Ar ²⁰³ is a benzene ring structure, and i3 is 0 or 1, preferably Ar ²⁰¹ is the aromatic hydrocarbon structure It has a hydrogen structure, more preferably a structure in which 1 to 5 benzene rings are connected, and more preferably one benzene ring.
Such a structure is expected to improve solubility and charge transport properties.

(III) Dendron A structure in which a dendron is bonded to ring A1 or ring A2, for example, Ar ²⁰¹ and Ar ²⁰² are benzene ring structures, Ar ²⁰³ is a biphenyl or terphenyl structure, i1 and i2 are 1 to 6, i3 is 2, j is 2.
Such a structure is expected to improve solubility and charge transport properties.

(IV) B ²⁰¹ -L ²⁰⁰ -B ²⁰²
The structure represented by B ²⁰¹ -L ²⁰⁰ -B ²⁰² is preferably a structure represented by the following formula (203) or the following formula (204).

In formula (203), R ²¹¹ , R ²¹² , and R ²¹³ each independently represent a substituent.
In formula (204), ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom, which may have a substituent. Ring B3 is preferably a pyridine ring.

(Preferred phosphorescent material)
The phosphorescent material represented by the above formula (201) is not particularly limited, but the following are preferred.

Also preferred is a phosphorescent material represented by the following formula (205).

[In formula (205), M ² represents a metal, and T represents a carbon atom or a nitrogen atom. R ⁹² to R ⁹⁵ each independently represent a substituent. However, when T is a nitrogen atom, R ⁹⁴ and R ⁹⁵ are absent. ]

In formula (205), specific examples of M ² include metals selected from Groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold is preferred, and divalent metals such as platinum and palladium are particularly preferred.

In addition, in formula (205), R ⁹² and R ⁹³ are each independently a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, It represents an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group.

Further, when T is a carbon atom, R ⁹⁴ and R ⁹⁵ each independently represent a substituent represented by the same examples as R ⁹² and R ⁹³ . Further, when T is a nitrogen atom, R ⁹⁴ or R ⁹⁵ directly bonded to T does not exist. Furthermore, R ⁹² to R ⁹⁵ may further have a substituent. As the substituent, the above-mentioned substituents can be used. Furthermore, any two or more groups among R ⁹² to R ⁹⁵ may be linked to each other to form a ring.

(molecular weight)
The molecular weight of the phosphorescent material is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less. Further, the molecular weight of the phosphorescent material is preferably 800 or more, more preferably 1000 or more, still more preferably 1200 or more. It is considered that by having a molecular weight in this range, the phosphorescent materials do not aggregate with each other and are uniformly mixed with the charge transporting material, thereby making it possible to obtain a luminescent layer with high luminous efficiency.

The molecular weight of the phosphorescent material is high in Tg, melting point, decomposition temperature, etc., the phosphorescent material and the formed light emitting layer have excellent heat resistance, and the film quality due to gas generation, recrystallization, molecular migration, etc. A larger value is preferable in that it is less likely to cause a decrease in the concentration of impurities or an increase in impurity concentration due to thermal decomposition of the material. On the other hand, the molecular weight of the phosphorescent material is preferably small in terms of ease of purification of the organic compound.

<Charge transport material>
The charge transport material used in the light emitting layer is a material having a skeleton with excellent charge transport properties, and may be selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes. preferable.

Examples of skeletons with excellent charge transport properties include aromatic structures, aromatic amine structures, arylamine structures, dibenzofuran structures, naphthalene structures, phenanthrene structures, phthalocyanine structures, porphyrin structures, thiophene structures, benzylphenyl structures, and fluorene structures. structure, quinacridone structure, triphenylene structure, carbazole structure, pyrene structure, anthracene structure, phenanthroline structure, quinoline structure, pyridine structure, pyrimidine structure, triazine structure, oxadiazole structure, or imidazole structure.

As the electron-transporting material, compounds having a pyridine structure, a pyrimidine structure, or a triazine structure are more preferable from the viewpoint of being a material with excellent electron-transporting properties and a relatively stable structure. is even more preferable.

The hole-transporting material is a compound having a structure with excellent hole-transporting properties, and among the central skeletons with excellent charge-transporting properties, a carbazole structure, a dibenzofuran structure, an arylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure is used. The structure is preferable as a structure having excellent hole transport properties, and a carbazole structure, a dibenzofuran structure, or an arylamine structure is more preferable.

The charge transport material used in the light emitting layer preferably has a fused ring structure of 3 or more rings, and is a compound having two or more fused ring structures of 3 or more rings or a compound having at least one fused ring of 5 or more rings. is even more preferable. These compounds increase the rigidity of molecules, making it easier to obtain the effect of suppressing the degree of molecular motion in response to heat. Further, the fused rings of 3 or more rings and the fused rings of 5 or more rings preferably have an aromatic hydrocarbon ring or an aromatic heterocycle from the viewpoint of charge transportability and material durability.

Specifically, the fused ring structure of three or more rings includes an anthracene structure, a phenanthrene structure, a pyrene structure, a chrysene structure, a naphthacene structure, a triphenylene structure, a fluorene structure, a benzofluorene structure, an indenofluorene structure, an indrofluorene structure, Examples include a carbazole structure, an indenocarbazole structure, an indolocarbazole structure, a dibenzofuran structure, and a dibenzothiophene structure. From the viewpoint of charge transport properties and solubility, at least one selected from the group consisting of a phenanthrene structure, a fluorene structure, an indenofluorene structure, a carbazole structure, an indenocarbazole structure, an indolocarbazole structure, a dibenzofuran structure, and a dibenzothiophene structure. Preferably, a carbazole structure or an indolocarbazole structure is more preferable from the viewpoint of durability against charges.

In the present invention, from the viewpoint of charge durability of the organic electroluminescent device, it is preferable that at least one of the charge transport materials in the light emitting layer is a material having a pyrimidine skeleton or a triazine skeleton.

The charge transport material of the light emitting layer is preferably a polymeric material from the viewpoint of excellent flexibility. A light-emitting layer formed using a material with excellent flexibility is preferable as a light-emitting layer of an organic electroluminescent device formed on a flexible substrate. When the charge transporting material contained in the light-emitting layer is a polymeric material, the molecular weight is preferably 5,000 or more and 1,000,000 or less, more preferably 10,000 or more and 500,000 or less, and even more preferably 10,000 or more and 500,000 or less. 000 or more and 100,000 or less.

In addition, the charge transport material for the light emitting layer should be selected from the viewpoints of ease of synthesis and purification, ease of designing electron transport performance and hole transport performance, and ease of adjusting viscosity when dissolved in a solvent. Preferably, it is a low molecule. When the charge transport material contained in the light emitting layer is a low molecular weight material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less. ,000 or less, preferably 300 or more, more preferably 350 or more, still more preferably 400 or more.

<Fluorescent material>
The fluorescent material is not particularly limited, but a compound represented by the following formula (211) is preferred.

In the above formula (211), Ar ²⁴¹ represents an aromatic hydrocarbon condensed ring structure which may have a substituent, Ar ²⁴² and Ar ²⁴³ each independently an alkyl group which may have a substituent, Represents an aromatic hydrocarbon group, an aromatic heterogroup, or a group in which these are bonded. n41 is an integer from 1 to 4.

Ar ²⁴¹ preferably represents an aromatic hydrocarbon condensed ring structure having 10 to 30 carbon atoms, and specific ring structures include naphthalene, acenaphthene, fluorene, anthracene, phenathrene, fluoranthene, pyrene, tetracene, chrysene, perylene, etc. Can be mentioned.
Ar ²⁴¹ is more preferably an aromatic hydrocarbon condensed ring structure having 12 to 20 carbon atoms, and specific ring structures include acenaphthene, fluorene, anthracene, phenathrene, fluoranthene, pyrene, tetracene, chrysene, and perylene. .
Ar ²⁴¹ is more preferably an aromatic hydrocarbon condensed ring structure having 16 to 18 carbon atoms, and specific examples of the ring structure include fluoranthene, pyrene, and chrysene.

n41 is 1 to 4, preferably 1 to 3, more preferably 1 to 2, and most preferably 2.

The alkyl group for Ar ²⁴² and Ar ²⁴³ is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms.
The aromatic hydrocarbon group for Ar ²⁴² and Ar ²⁴³ is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms, and most preferably a phenyl group. , is a naphthyl group.
The aromatic heterogroup of Ar ²⁴² and Ar ²⁴³ is preferably an aromatic heterogroup having 3 to 30 carbon atoms, more preferably an aromatic hydrocarbon group having 5 to 24 carbon atoms, specifically a carbazolyl group, A dibenzofuranyl group and a dibenzothiophenyl group are preferred, and a dibenzofuranyl group is more preferred.

The substituent that Ar ²⁴¹ , Ar ²⁴² , and Ar ²⁴³ may have is preferably a group selected from the substituent group S, more preferably a hydrocarbon group included in the substituent group S, and even more preferably is a hydrocarbon group among the groups preferable as the substituent group S.

The charge transport material used together with the fluorescent material is not particularly limited, but is preferably one represented by the following formula (212).

In the above formula (212), R ²⁵¹ and R ²⁵² are each independently a structure represented by formula (213), and R ²⁵³ represents a substituent, and when there is a plurality of R ²⁵³ , they may be the same or different. and n43 is an integer from 0 to 8.

In the above formula (213), * represents a bond with the anthracene ring of formula (212), and Ar ²⁵⁴ and Ar ²⁵⁵ each independently represent an aromatic hydrocarbon structure that may have a substituent, or a substituted Represents a heteroaromatic ring structure which may have a group, Ar ²⁵⁴ and Ar ²⁵⁵ each may be the same or different when there is a plurality of them, n44 is an integer of 1 to 5, and n45 is 0 to 5. It is an integer of 5.

Ar ²⁵⁴ is preferably a monocyclic or fused ring aromatic hydrocarbon structure having 6 to 30 carbon atoms, which may have a substituent, and more preferably has a substituent. , a monocyclic or fused ring aromatic hydrocarbon structure having 6 to 12 carbon atoms.

Ar ²⁵⁵ is preferably a monocyclic or fused ring aromatic hydrocarbon structure having 6 to 30 carbon atoms, which may have a substituent, or an aromatic hydrocarbon structure having 6 to 30 carbon atoms, which may have a substituent. It is an aromatic heterocyclic structure that is a condensed ring of. Ar ²⁵⁵ is more preferably a monocyclic or fused ring aromatic hydrocarbon structure having 6 to 12 carbon atoms, which may have a substituent, or an aromatic hydrocarbon structure having 12 carbon atoms, which may have a substituent. It is an aromatic heterocyclic structure that is a fused ring.

n44 is preferably an integer of 1 to 3, more preferably 1 or 2.
n45 is preferably an integer of 0 to 3, more preferably 0 to 2.

The substituent that R ²⁵³ , Ar ²⁵⁴ and Ar ²⁵⁵ may have is preferably a group selected from the above-mentioned substituent group S. More preferably, it is a hydrocarbon group included in the substituent group S, and still more preferably a hydrocarbon group among the groups preferable as the substituent group S.

The molecular weight of the fluorescent material and the charge transport material is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less. Moreover, it is preferably 300 or more, more preferably 350 or more, and still more preferably 400 or more.

[Hole blocking layer]
A hole blocking layer may be provided between the light emitting layer 5 and the electron injection layer described below. The hole blocking layer is a layer stacked on the light emitting layer 5 so as to be in contact with the interface of the light emitting layer 5 on the cathode 7 side.

This hole blocking layer has the role of blocking holes moving from the anode 2 from reaching the cathode 7 and the role of efficiently transporting electrons injected from the cathode 7 toward the light emitting layer 5. have The physical properties required of the material constituting the hole blocking layer include high electron mobility and low hole mobility, large energy gap (difference between HOMO and LUMO), and excited triplet level (T ₁ ). One example is the high level of

Examples of materials for the hole blocking layer that satisfy these conditions include bis(2-methyl-8-quinolinolato)(phenolato)aluminum, bis(2-methyl-8-quinolinolato)(triphenylsilanolate)aluminum, etc. mixed ligand complexes, metal complexes such as bis(2-methyl-8-quinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolilato)aluminum dinuclear metal complexes, distyrylbiphenyl derivatives, etc. Styryl compounds (Japanese Unexamined Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole ( Japanese Patent Application Publication No. 7-41759), phenanthroline derivatives such as bathocuproine (Japanese Patent Application Publication No. 10-79297), and the like. Furthermore, a compound having at least one pyridine ring substituted at the 2, 4, and 6 positions described in International Publication No. 2005/022962 is also preferable as a material for the hole blocking layer.

There are no restrictions on the method of forming the hole blocking layer. Therefore, it can be formed by a wet film formation method, a vapor deposition method, or other methods.

The thickness of the hole blocking layer is arbitrary as long as it does not significantly impair the effects of the present invention, but it 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 6 is provided between the light emitting layer 5 and the cathode 7 for the purpose of further improving the current efficiency of the device.

The electron transport layer 6 is formed of a compound that can efficiently transport electrons injected from the cathode 7 toward the light emitting layer 5 between the electrodes to which an electric field is applied. The electron-transporting compound used in the electron-transporting layer 6 must be a compound that has high electron injection efficiency from the cathode 7, has high electron mobility, and can efficiently transport the injected electrons. is necessary.

Specifically, examples of the electron transporting compound used in the electron transporting layer include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Unexamined Patent Publication No. 59-194393), 10-hydroxybenzo[h] Quinoline metal complexes, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (U.S. Patent No. 5645948), quinoxaline compounds (Japanese Unexamined Patent Publication No. 6-207169), phenanthroline derivatives (Japanese Unexamined Patent Publication No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyano Examples include anthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

The film thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

The electron transport layer 6 is formed by laminating it on the hole blocking layer using a wet film forming method or a vacuum evaporation method in the same manner as described above. Usually, a vacuum evaporation method is used.
In the present invention, as described above, an electron transport layer can be formed on a light emitting layer containing a suitable light emitting layer forming material by a wet film forming method.

[Electron injection layer]
The electron injection layer may be provided to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5.

In order to efficiently inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like. The film thickness is usually preferably 0.1 nm or more and 5 nm or less.

Furthermore, organic electron transport materials such as nitrogen-containing heterocyclic compounds such as bathophenanthroline and metal complexes such as aluminum complexes of 8-hydroxyquinoline are doped with alkali metals such as sodium, potassium, cesium, lithium, and rubidium ( (described in Japanese Unexamined Patent Application No. 10-270171, Japanese Unexamined Patent Publication No. 2002-100478, Japanese Unexamined Patent Application No. 2002-100482, etc.) also improves electron injection and transport properties and achieves excellent film quality. This is preferable because it makes it possible to

The thickness of the electron injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer is formed by laminating it on the light emitting layer 5 or the hole blocking layer or electron transport layer 6 thereon by a wet film formation method or a vacuum evaporation method.
The details in the case of the wet film forming method are the same as in the case of the above-mentioned light emitting layer.

In some cases, the hole-blocking layer, electron-transporting layer, and electron-injecting layer are made into a single layer by co-doping an electron-transporting material and a lithium complex.

[cathode]
The cathode 7 plays a role of injecting electrons into a layer (such as an electron injection layer or a light emitting layer) on the side of the light emitting layer 5 .

As the material for the cathode 7, it is possible to use the material used for the anode 2, but in order to efficiently inject electrons, it is preferable to use a metal with a low work function, such as tin, magnesium, etc. , indium, calcium, aluminum, silver, or alloys thereof. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy, and the like.

In terms of the stability of the organic electroluminescent device, it is preferable to protect the cathode made of a metal with a low work function by laminating a metal layer with a high work function and stable against the atmosphere on the cathode. Examples of the metal to be laminated include metals such as aluminum, silver, copper, nickel, chromium, gold, and platinum.

The film thickness of the cathode is usually the same as that of the anode.

[Other layers]
The organic electroluminescent device of the present invention may further have other layers as long as the effects of the present invention are not significantly impaired. That is, any other layer mentioned above may be provided between the anode and the cathode.

[Other element configurations]
The organic electroluminescent device of the present invention has a structure opposite to that described above, that is, for example, on a substrate, a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light emitting layer, a hole transport layer, a hole It is also possible to stack the injection layer and the anode in this order.

When applying the organic electroluminescent device of the present invention to an organic electroluminescent device, it may be used as a single organic electroluminescent device or in a configuration in which a plurality of organic electroluminescent devices are arranged in an array. A structure in which anodes and cathodes are arranged in an XY matrix may also be used.

[Method for manufacturing organic electroluminescent device]
The method for producing an organic electroluminescent device of the present invention is a method for producing an organic electroluminescent device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer being separated from a solvent. The method may include a step of forming a film by a wet film forming method using the composition of the present invention containing the composition of the present invention.

In the method for manufacturing an organic electroluminescent device of the present invention, the organic layer is preferably an organic layer between the anode and the light emitting layer.

[Display device]
The display device (organic electroluminescent device display device) of the present invention includes the organic electroluminescent device of the present invention. There are no particular limitations on the type or structure of the display device of the present invention, and it can be assembled using the organic electroluminescent device of the present invention according to a conventional method.

For example, the organic EL display device of the present invention can be manufactured by the method described in "Organic EL Display" (Ohmsha, published August 20, 2004, written by Shizushi Tokito, Chihaya Adachi, and Hideyuki Murata). can be formed.

[Lighting device]
The lighting device (organic electroluminescent device lighting device) of the present invention includes the organic electroluminescent device of the present invention. There are no particular limitations on the type or structure of the illumination device of the present invention, and it can be assembled using the organic electroluminescent device of the present invention according to a conventional method.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following examples, and the present invention can be implemented with arbitrary changes without departing from the gist thereof.

In addition, in this specification, Ac means an acetyl group, Ph means a phenyl group, dba means dibenzylideneacetone, and Amphos means [4-(N,N-dimethylamino)phenyl]di-tert -butylphosphine, ^tBu means tert-butyl group, and dppf means 1,1'-bis(diphenylphosphino)ferrocene.

<Synthesis of compound 1>
(Synthesis of intermediate 1-2)

4-bromoaniline (14.5 g, 84.29 mmol), intermediate 1-1 (8.3 g, 19.22 mmol), potassium phosphate (2M aqueous solution, 104 mL), and toluene (210 mL), ethanol (104 mL). The mixture was placed in a flask, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 60°C. Bis(triphenylphosphine)palladium(II) dichloride (0.25 g, 0.36 mmol) was added and stirred at 63° 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. The crude product was purified by column chromatography to obtain Intermediate 1-2 (2.9 g, yield 72%).

(Synthesis of intermediate 1-3)

Intermediate 1-2 (2.9 g, 13.86 mmol), 2-bromo-9,9'-spirobifluorene (5.21 g, 13.18 mmol) and sodium tert-butoxy (3.6 g, 35.59 mmol) and toluene (60 mL), the system was sufficiently purged with nitrogen, and heated to 60°C (solution A1-1). To a 10 mL toluene solution of tris(dibenzylideneacetone)dipalladium chloroform complex (0.34 g, 0.33 mmol) was added 1,1'-bis(diphenylphosphino)ferrocene (dppf) (0.73 g, 1.32 mmol). and heated to 60°C (solution B1-1).
Solution B1-1 was added to solution A1-1 in a nitrogen stream, and the mixture was heated under reflux for 2.5 hours. After cooling to room temperature, toluene (200 mL) and water (100 mL) were added to the reaction solution, stirred, and then separated. The aqueous layer was extracted with toluene (100 mL x 2), the organic layers were combined, and the mixture was extracted with magnesium sulfate. After drying, it was concentrated. Further purification by silica gel column chromatography gave Intermediate 1-3 (3.6 g, yield 52%) as a pale yellow oil.

(Synthesis of compound 1)

Intermediate 1-3 (3.6 g, 6.87 mmol), 1,3-dibromobenzene (0.77 g, 3.27 mmol) and sodium tert-butoxy (1.9 g, 19.62 mmol), toluene (55 mL) After charging, the system was sufficiently purged with nitrogen and heated to 60°C (solution A1-2). To a solution of tris(dibenzylideneacetone)dipalladium chloroform complex (0.136 g, 0.131 mmol) in 10 mL of toluene was added [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.1 g, 0.131 mmol). 28g, 1.06mmol) was added thereto and heated to 60°C (Solution B1-2).
Solution B1-2 was added to solution A1-2 in a nitrogen stream, and the mixture was heated under reflux for 3 hours. After cooling to room temperature, toluene (200 mL) and water (100 mL) were added to the reaction solution, stirred, and then separated. The aqueous layer was extracted with toluene (100 mL x 2), the organic layers were combined, and the mixture was extracted with magnesium sulfate. After drying, it was concentrated. Further purification by silica gel column chromatography gave Compound 1 (1.9 g, yield 52%) as a colorless solid.

<Synthesis of compound 2>
(Synthesis of intermediate 2-1)

3-bromoaniline (5.90 g, 34.30 mmol), intermediate 1-1 (7.39 g, 17.11 mmol), potassium phosphate (2M aqueous solution, 42 mL), and toluene (176 mL), ethanol (88 mL). The mixture was placed in a flask, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 60°C. Tetrakis(triphenylphosphine)palladium(0) (0.7946 g, 0.69 mmol) was added and stirred at 100° C. for 3 hours. Water was added to the reaction solution, and extraction was performed with toluene. The organic layer was dried over anhydrous sodium sulfate. The crude product was purified by column chromatography to obtain Intermediate 2-1 (6.8 g, yield 95%).

(Synthesis of intermediate 2-2)

Intermediate 2-1 (2.97 g, 14.19 mmol), 2-bromo-9,9'-spirobifluorene (5.18 g, 13.10 mmol) and tert-butoxy sodium (3.57 g, 37.15 mmol) and toluene (47 mL), the system was sufficiently purged with nitrogen, and heated to 60°C (solution A2-1). To a 10 mL solution of tris(dibenzylideneacetone) dipalladium chloroform complex (0.1855 g, 0.1792 mmol) in toluene was added 1,1'-bis(diphenylphosphino)ferrocene (0.3880 g, 0.6998 mmol), and 60 The mixture was heated to ℃ (solution B2-1).
Solution B2-1 was added to solution A2-1 in a nitrogen stream, and the mixture was heated under reflux for 2 hours. After cooling to room temperature, methylene chloride was added to the reaction solution, stirred, filtered under suction, and concentrated. Further purification by silica gel column chromatography gave Intermediate 2-2 (4.99 g, yield 73%) as a pale yellow oil.

(Synthesis of compound 2)

Intermediate 2-2 (4.9930 g, 9.5344 mmol), 1,3-dibromobenzene (1.06 g, 4.4932 mmol) and tert-butoxy sodium (2.2529 g, 23.4433 mmol), toluene (90 mL) After charging, the system was sufficiently purged with nitrogen and heated to 60°C (solution A2-2). To a solution of tris(dibenzylideneacetone)dipalladium chloroform complex (0.0836 g, 0.0913 mmol) in 10 mL of toluene was added [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.0 mL). 1874 g, 0.7061 mmol) was added and heated to 60° C. (Solution B2-2).
Solution B2-2 was added to solution A2-2 in a nitrogen stream, and the mixture was heated under reflux for 3 hours. After cooling to room temperature, methylene chloride (100 mL) was added to the reaction solution, stirred, filtered under suction, and concentrated. Further purification by silica gel column chromatography gave Compound 2 (1.95 g, yield 39%) as a colorless solid.

<Synthesis of compound 3>
(Synthesis of intermediate 3-3)

Intermediate 3-1 (0.50 g, 0.77 mmol), Intermediate 3-2 (1.23 g, 3.83 mmol) with nitrogen bubbling toluene (20 mL), ethanol (10 mL), tripotassium phosphate aqueous solution (2.0 mol/L, 10 mL) were added in order and heated to 50°C. Then, Pd(PPh ₃ ) ₄ (44 mg, 0.038 mmol) was added and stirred at 90° C. for 6 hours. After cooling to room temperature, a saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 3-3 (0.62 g, 73% yield).

(Synthesis of compound 3)

Intermediate 3-3 (0.62 g, 0.56 mmol), bromobenzene (0.18 g, 1.12 mmol), and sodium tert-butoxy (0.15 g, 1.51 mmol) were bubbled with toluene (20 mL). (Solution A3-1). Amphos (0.12 g, 0.45 mmol) was added to a solution of tris(dibenzylideneacetone)dipalladium (Pd ₂ (dba) ₃ ) (51 mg, 0.056 mmol) in toluene (5 ml) and heated to 50°C ( Solution B3-1). Solution B3-1 was added to solution A3-1 in a nitrogen stream, and the mixture was heated under reflux for 7.5 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Compound 3 (0.21 g, 32% yield).

<Synthesis of compound 4>
(Synthesis of intermediate 4-3)

Intermediate 4-1 (6.68 g, 24.5 mmol), Intermediate 4-2 (6.00 g, 24.5 mmol), and sodium tert-butoxy (6.35 g, 66.0 mmol) in toluene with nitrogen bubbling. (90 mL) was added (solution A4-1). dppf (1.36 g, 2.45 mmol) was added to a toluene (30 ml) solution of Pd ₂ (dba) ₃ CHCl ₃ (0.63 g, 0.61 mmol) and stirred at room temperature for 15 minutes (solution B4-1). . Solution B4-1 was added to solution A4-1 in a nitrogen stream, and the mixture was heated under reflux for 6 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 4-3 (8.62 g, 81% yield).

(Synthesis of compound 4)

Intermediate 4-3 (2.83 g, 6.46 mmol), 3,3'-dibromobiphenyl (0.96 g, 3.08 mmol), and sodium tert-butoxy (1.60 g, 16.6 mmol) were subjected to nitrogen bubbling. Toluene (50 mL) was added (solution A4-2). Amphos (0.65 g, 2.46 mmol) was added to a solution of Pd ₂ (dba) ₃ (0.28 g, 0.31 mmol) in toluene (15 ml) and heated to 50° C. (solution B4-2). Solution B4-2 was added to solution A4-2 in a nitrogen stream, and the mixture was heated under reflux for 6 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Compound 4 (0.70 g, 22% yield).

<Synthesis of compound 5>
(Synthesis of compound 5)

Nitrogen bubbling into Intermediate 4-3 (4.38 g, 10.0 mmol), 1,3,5-tribromobenzene (1.00 g, 3.18 mmol), and sodium tert-butoxy (2.47 g, 25.7 mmol) Toluene (50 mL) was added (solution A5-1). Amphos (0.67 g, 2.54 mmol) was added to a toluene (20 ml) solution of Pd ₂ (dba) ₃ (0.29 g, 0.32 mmol) and heated to 50° C. (solution B5-1). Solution B5-1 was added to solution A5-1 in a nitrogen stream, and the mixture was heated under reflux for 6 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Compound 5 (yield: 0.50 g, yield: 11%).

<Synthesis of comparative compound 1>
(Synthesis of intermediate C1-2)

Intermediate C1-1 (2.88 g, 13.6 mmol), 2-bromo-9,9'-spirobi[9H-fluorene] (5.13 g, 12.9 mmol), tert-butoxysodium (3.35 g, 34 Toluene (30 mL) with nitrogen bubbling was added to the solution (solution C1-1). To a solution of Pd ₂ (dba) ₃ CHCl ₃ (0.33 g, 0.32 mmol) in toluene (15 ml) was added dppf (0.72 g, 1.29 mmol), and the mixture was stirred at room temperature for 10 minutes (solution D1-1). . Solution D1-1 was added to solution C1-1 in a nitrogen stream, and the mixture was heated under reflux for 4 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate C1-2 (yield: 5.99 g, yield: 88%).

(Synthesis of comparative compound 1)

Intermediate C1-2 (3.37 g, 6.41 mmol), 1-bromo-3-iodobenzene (0.86 g, 3.05 mmol), and sodium tert-butoxy (1.58 g, 16.5 mmol) were bubbled with nitrogen. Toluene (50 mL) was added (solution C1-2). Amphos (0.66 g, 2.48 mmol) was added to a solution of Pd ₂ (dba) ₃ (0.28 g, 0.31 mmol) in toluene (15 ml) and heated to 50° C. (solution C1-2). Solution D1-2 was added to solution C1-2 in a nitrogen stream, and the mixture was heated under reflux for 2 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Comparative Compound 1 (1.2 g, 35% yield).

<Synthesis of comparative compound 2>
(Synthesis of intermediate C2-2)

Intermediate C2-1 (0.76 g, 1.17 mmol), phenylboronic acid (0.86 g, 7.02 mmol) in toluene (20 mL) with nitrogen bubbling, ethanol (10 mL), tripotassium phosphate aqueous solution (2 0 mol/L, 10 mL) were added in this order and heated to 50°C. Then, Pd(PPh ₃ ) ₄ (81 mg, 0.070 mmol) was added and stirred at 90° C. for 6 hours. After cooling to room temperature, a saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate C2-2 (0.68 g, 91% yield).

(Synthesis of comparative compound 2)

Intermediate C2-2 (0.62 g, 0.96 mmol), 4-bromobiphenyl (0.34 g, 1.45 mmol), and tert-butoxysodium (0.25 g, 2.59 mmol) were mixed with toluene through nitrogen bubbling ( 20 mL) was added (solution C2-1). Amphos (20.4 mg, 0.076 mmol) was added to a solution of Pd ₂ (dba) ₃ (8.8 mg, 0.0096 mmol) in toluene (10 ml) and heated to 50° C. (solution D2-1). Solution D2-1 was added to solution C2-1 in a nitrogen stream, and the mixture was heated under reflux for 3.5 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Comparative Compound 2 (yield: 0.63 g, yield: 83%).

<Synthesis of comparative compound 3>
(Synthesis of intermediate C3-2)

Intermediate C3-1 (5.08 g, 12.7 mmol), 4-vinylphenylboronic acid (1.87 g, 12.7 mmol) with nitrogen bubbled toluene (40 mL), ethanol (20 mL), tripotassium phosphate Aqueous solutions (2.0 mol/L, 20 mL) were sequentially added and heated to 50°C. Then, Pd(PPh ₃ ) ₄ (0.146 g, 0.127 mmol) was added and stirred at 90° C. for 4 hours. After cooling to room temperature, a saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate C3-2 (0.88 g, 16% yield).

(Synthesis of comparative compound 3)

Intermediate C3-2 (0.79 g, 1.87 mmol), N,N'-diphenylbenzidine (0.29 g, 0.848 mmol), and sodium tert-butoxy (0.44 g, 4.58 mmol) were subjected to nitrogen bubbling. Toluene (30 mL) was added (solution C3-1). Amphos (0.18 g, 0.68 mmol) was added to a solution of Pd ₂ (dba) ₃ (77.7 mg, 0.085 mmol) in toluene (10 ml) and heated to 50° C. (solution D3-1). Solution D3-1 was added to solution C3-1 in a nitrogen stream, and the mixture was heated under reflux for 4 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Comparative Compound 3 (0.58 g, 67% yield).

<Evaluation of solvent resistance>
Formation of a film for evaluating solvent resistance using the obtained compound and evaluation of solvent resistance of the obtained film were carried out as follows.
First, a solution was prepared in which Compound A was dissolved in ethyl benzoate at a concentration of 2.0% by mass and Compound B at a concentration of 0.4% by mass.
This solution was dropped onto an ITO substrate in the atmosphere for spin coating, and dried on a hot plate at 100° C. for 1 minute. Next, ultraviolet irradiation was performed using a spot light source LC8 manufactured by Hamamatsu Photonics. Ultraviolet irradiation was performed at an intensity of 46 mW/cm ² for 90 seconds. This substrate was dried on a hot plate at 230° C. to form a film for evaluating solvent resistance with a thickness of 30 nm.

Next, the substrate on which the film for evaluating solvent resistance was formed was set in a spin coater, and 150 μL of the test solvent was dropped onto the substrate, and after the dropping, it was allowed to stand for 90 seconds to perform a solvent resistance test. Phenylcyclohexane was used as the test solvent.
Thereafter, the substrate was rotated at 1500 rpm for 30 seconds and then at 4000 rpm for 30 seconds to spin out the dropped solvent. This substrate was dried on a hot plate at 145° C. for 15 minutes. Solvent resistance was estimated from the change in film thickness before and after the solvent resistance test.

The solvent resistance of the compound after film formation was evaluated based on the following criteria.
○○: No decrease in film thickness was observed.
○: 80% or more of the film remained.
×: The film melted and disappeared.

Table 1 summarizes the combinations of Compound A and Compound B and the time (bake time) for drying on a 230° C. hot plate after UV irradiation. Table 1 also summarizes the membranes prepared and the results of their solvent resistance tests.

<Production of organic electroluminescent device>
[Example 1]
An organic electroluminescent device was produced by the following method.
An indium tin oxide (ITO) transparent conductive film deposited to a thickness of 50 nm on a glass substrate (manufactured by Geomatec, sputtering film) was formed into 2 mm wide stripes using normal photolithography technology and hydrochloric acid etching. The anode was formed by patterning. The substrate on which ITO was patterned was washed in the following order: ultrasonic cleaning with an aqueous surfactant solution, washing with ultrapure water, ultrasonic washing with ultrapure water, and washing with ultrapure water, and then dried with compressed air. Finally, ultraviolet ozone cleaning was performed.

As a composition for forming a hole injection layer, 2.0% by weight of compound 3 having a structure included in formula (3-4) and an electron-accepting compound (A-1) having a structure included in formula (81) were added. ) was dissolved in ethyl benzoate at a concentration of 0.4% by weight to prepare the composition of the present invention.
This composition was spin-coated on the substrate in the air, and dried on a hot plate at 100° C. for 1 minute. Next, ultraviolet irradiation was performed using a spot light source LC8 manufactured by Hamamatsu Photonics. Ultraviolet irradiation was performed at an intensity of 46 mW/cm ² for 90 seconds. This substrate was dried on a hot plate in the air at 230° C. for 30 minutes to form a uniform thin film with a thickness of 30 nm, which was used as a hole injection layer.

Next, a charge transporting polymer compound having the following structural formula (HT-1) was dissolved in cyclohexylbenzene to prepare a 3.0% by weight solution.
This solution was spin-coated on the substrate on which the hole injection layer was coated in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 50 nm. and formed a hole transport layer.

Subsequently, as materials for the light emitting layer, 1.25% by weight of a compound (H-1) having the following structure, 1.25% by weight of (H-2), 2.5% by weight of (H-3), ( D-1) was dissolved in cyclohexylbenzene at a concentration of 1.5% by weight to prepare a composition for forming a light-emitting layer.

This solution was spin-coated on the substrate on which the hole transport layer was coated in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 70 nm. A light-emitting layer was formed.
The substrate on which the film up to the light-emitting layer was formed was placed in a vacuum evaporation apparatus, and the inside of the apparatus was evacuated to a pressure of 2×10 ⁻⁴ Pa or less.

Next, the following structural formula (ET-1) and 8-hydroxyquinolinolatrithium were co-deposited on the light emitting layer using a vacuum evaporation method at a film thickness ratio of 2:3, and an electron transport layer with a film thickness of 30 nm was formed. was formed.

Next, a striped shadow mask with a width of 2 mm was brought into close contact with the substrate as a mask for cathode evaporation, perpendicular to the ITO stripes of the anode, and the aluminum was heated with a molybdenum boat to form an aluminum layer with a thickness of 80 nm. was formed to form a cathode. In the manner described above, an organic electroluminescent device having a light emitting area of 2 mm x 2 mm in size was obtained.

[Example 2]
The composition for forming a hole injection layer of the present invention contains 2.0% by weight of compound 3 contained in formula (3-4) and an electron-accepting compound (A-2) having a structure contained in formula (81). ) was dissolved in ethyl benzoate at a concentration of 0.4% by weight to prepare a composition, and an organic electroluminescent device was produced in the same manner as in Example 1, except that a hole injection layer was formed using this composition. did.

[Example 3]
The composition for forming a hole injection layer of the present invention contains 2.0% by weight of compound 2 contained in formula (3-1) and 0% by weight of electron-accepting compound (A-1) contained in formula (81). An organic electroluminescent device was produced in the same manner as in Example 1, except that a composition was prepared by dissolving it in ethyl benzoate at a concentration of .4% by weight, and a hole injection layer was formed using this composition.

[Comparative example 1]
As a composition for forming a hole injection layer for comparison, benzoin was used at a concentration of 2.0% by weight of Comparative Compound 3 and 0.4% by weight of the electron-accepting compound (A-1) contained in formula (81). An organic electroluminescent device was produced in the same manner as in Example 1, except that a composition was prepared by dissolving it in ethyl acid, and a hole injection layer was formed using this composition.

[Evaluation of element]
The current efficiency (cd/A) of the organic electroluminescent devices obtained in Examples 1 to 3 and Comparative Example 1 when emitting light at 1,000 cd/m ² was measured. Table 2 shows the results when Comparative Example 1 was set as 1.
From the results in Table 2, it was found that the organic electroluminescent device using the composition of the present invention had improved luminous efficiency.

[Example 4]
As a composition for forming a hole injection layer of the present invention, 1.0% by weight of Compound 1 having a structure included in formula (3-1), hole transporting property having a repeating structure of the following formula (P-1) A composition was prepared by dissolving the polymer compound at a concentration of 1.0% by weight and the electron-accepting compound (A-1) included in formula (81) at a concentration of 0.4% by weight in ethyl benzoate.

This composition was spin-coated on the above substrate in the atmosphere, and dried on a hot plate in the atmosphere at 230°C for 30 minutes to form a uniform thin film with a thickness of 30 nm, which was used as a hole injection layer. An organic electroluminescent device was produced in the same manner as in Example 1.

[Example 5]
The composition for forming a hole injection layer of the present invention contains 1.0% by weight of compound 2 contained in formula (3-1), 1.0% by weight of (P-1), and 1.0% by weight of compound 2 contained in formula (81). Example 4 was repeated, except that the electron-accepting compound (A-1) was dissolved in ethyl benzoate at a concentration of 0.4% by weight to prepare a composition, and the hole injection layer was formed using this composition. An organic electroluminescent device was produced in the same manner.

[Comparative example 2]
As a comparative hole injection layer forming composition, 1.0% by weight of compound 2 contained in formula (3-1), 1.0% by weight of polymer compound (P-1), and electron-accepting The organic compound was prepared in the same manner as in Example 4, except that the compound (CA-1) was dissolved in ethyl benzoate at a concentration of 0.4% by weight to prepare a composition, and the hole injection layer was formed using this composition. An electroluminescent device was fabricated.

[Evaluation of element]
The current efficiency (cd/A) of the organic electroluminescent devices obtained in Examples 4 and 5 and Comparative Example 2 was measured when the organic electroluminescent devices were made to emit light at 1,000 cd/m ² . Table 3 shows the results when Comparative Example 2 was set as 1.
From the results in Table 3, it was found that the organic electroluminescent device using the composition of the present invention had improved luminous efficiency.

In the organic electroluminescent devices obtained in Example 3 and Example 5, the time (LT95) for the luminance to decrease to 95% of the initial luminance when the device is continuously energized at a current density of 15 mA/cm ² was determined. It was measured. The results of these measurements are shown in Table 4. In Table 4, the values of Example 5 are relative values with the value of Example 3 being 1.
From the results in Table 4, it was found that the organic electroluminescent device in which the polymer was added to the composition of the present invention had improved luminous efficiency and driving life.

[Example 6]
An organic electroluminescent device was produced by the following method.
An indium tin oxide (ITO) transparent conductive film deposited to a thickness of 50 nm on a glass substrate (manufactured by Geomatec, sputtering film) was formed into 2 mm wide stripes using normal photolithography technology and hydrochloric acid etching. The anode was formed by patterning. The substrate on which ITO was patterned was washed in the following order: ultrasonic cleaning with an aqueous surfactant solution, washing with ultrapure water, ultrasonic washing with ultrapure water, and washing with ultrapure water, and then dried with compressed air. Finally, ultraviolet ozone cleaning was performed.

As a composition for forming a hole injection layer, 2.0% by weight of compound 4 having the structure included in formula (3-3) and 0% of the electron-accepting compound (A-1) included in formula (81) were used. The composition of the present invention was prepared by dissolving it in ethyl benzoate at a concentration of .4% by weight.
This composition was spin-coated on the substrate in the air, and dried on a hot plate at 100° C. for 1 minute. Next, ultraviolet irradiation was performed using a spot light source LC8 manufactured by Hamamatsu Photonics. Ultraviolet irradiation was performed at an intensity of 46 mW/cm ² for 90 seconds. This substrate was dried on a hot plate in the air at 230° C. for 30 minutes to form a uniform thin film with a thickness of 30 nm, which was used as a hole injection layer.

Next, a charge transporting polymer compound having the following structural formula (HT-1) was dissolved in cyclohexylbenzene to prepare a 3.0% by weight solution.
This solution was spin-coated on the substrate on which the hole injection layer was coated in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 40 nm. and formed a hole transport layer.

Subsequently, as materials for the light-emitting layer, a compound (H-4) having the following structure was dissolved in cyclohexylbenzene at a concentration of 4.0% by weight and (D-2) at a concentration of 0.4% by weight to form a composition for forming a light-emitting layer. I prepared something.

This solution was spin-coated on the substrate on which the hole transport layer was coated in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm. A light-emitting layer was formed.
After forming the light-emitting layer, an organic electroluminescent device was produced in the same manner as in Example 1.

[Example 7]
The composition for forming a hole injection layer of the present invention contains 2.0% by weight of compound 5 contained in formula (3-2) and 0% by weight of electron-accepting compound (A-2) contained in formula (81). An organic electroluminescent device was produced in the same manner as in Example 6, except that a composition was prepared by dissolving it in ethyl benzoate at a concentration of .4% by weight, and a hole injection layer was formed using this composition.

[Comparative example 3]
As a comparative hole injection layer forming composition, compound 4 contained in formula (3-3) was used at a concentration of 2.0% by weight and electron accepting compound (CA-1) at a concentration of 0.4% by weight. An organic electroluminescent device was produced in the same manner as in Example 6, except that a composition was prepared by dissolving it in ethyl benzoate, and a hole injection layer was formed using this composition.

[Comparative example 4]
A composition for forming a hole injection layer for comparison was prepared by dissolving Comparative Compound 3 at a concentration of 2.0% by weight and electron accepting compound (CA-1) at a concentration of 0.4% by weight in ethyl benzoate. An organic electroluminescent device was produced in the same manner as in Example 6, except that the material was prepared and used to form a hole injection layer.

[Example 8]
As the composition for forming a hole injection layer of the present invention, a hole transporting polymer compound containing 1.0% by weight of compound 4 contained in formula (3-3) and having a repeating structure of the following formula (P-2) is used. A composition was prepared by dissolving the electron-accepting compound (A-1) contained in formula (81) in ethyl benzoate at a concentration of 1.0% by weight and 0.4% by weight.

This composition was spin-coated on the above substrate in the atmosphere, and dried on a hot plate in the atmosphere at 230°C for 30 minutes to form a uniform thin film with a thickness of 30 nm, which was used as a hole injection layer. An organic electroluminescent device was produced in the same manner as in Example 6.

[Example 9]
The composition for forming a hole injection layer of the present invention contains 1.0% by weight of compound 5 contained in formula (3-2), 1.0% by weight of polymer compound (P-2), and 1.0% by weight of compound 5 contained in formula (3-2), and ) was dissolved in ethyl benzoate at a concentration of 0.4% by weight to prepare a composition, and the composition was used to form a hole injection layer. An organic electroluminescent device was produced in the same manner as in Example 8.

[Comparative example 5]
As a comparative hole injection layer forming composition, 1.0% by weight of comparative compound 3, 1.0% by weight of polymer compound (P-2), and an electron-accepting compound contained in formula (81). (A-1) was dissolved in ethyl benzoate at a concentration of 0.4% by weight to prepare a composition, and the organic electric field was A light emitting device was produced.

[Evaluation of element]
The current efficiency (cd/A) when the organic electroluminescent devices obtained in Examples 6 to 9 and Comparative Examples 3 to 5 were emitted at 1,000 cd/m ² was measured. Table 5 shows the results when Comparative Example 4 was set as 1.
From the results in Table 5, it was found that the organic electroluminescent device using the composition of the present invention had improved luminous efficiency.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various changes can be made without departing from the spirit and scope of the present invention.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can come up with various changes or modifications within the scope of the claims, and these naturally fall within the technical scope of the present invention. Understood. Further, each of the constituent elements in the above embodiments may be arbitrarily combined without departing from the spirit of the invention.

Note that this application is based on a Japanese patent application (Japanese Patent Application No. 2022-054580) filed on March 29, 2022, and the contents thereof are incorporated as a reference in this application.

The composition of the present invention can be used to improve the luminous efficiency of organic electroluminescent devices.

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

Claims

A composition comprising an arylamine compound represented by any of the following formulas (3-1) to (3-4) and an electron-accepting compound represented by the following formula (81).

(In formulas (3-1) to (3-4),
Ar 2 and Ar 3 are each independently one of formulas (4-1) to (4-3),
Each of the plurality of R 2 is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a2 are each independently 0 or 1,
Each of the plurality of A 2 's independently represents a hydrogen atom or a crosslinking group. )

(In formulas (4-1) to (4-3),
* represents the bonding position,
Each of the plurality of R 1 is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a1 are each independently 0 or 1,
Each of the plurality of A 1 's independently represents a hydrogen atom or a crosslinking group.
However, at least one of the group consisting of all A1 is the above-mentioned crosslinking group. )

(In formula (81), 5 R 81 , 5 R 82 , 5 R 83 , and 5 R 84 are each independent, and R 81 to R 84 are each independently a hydrogen atom, a heavy Hydrogen atom, halogen atom, aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, fluorine substitution an alkyl group having 1 to 12 carbon atoms, or a crosslinking group.
Ph 1 , Ph 2 , Ph 3 , and Ph 4 are symbols indicating respective benzene rings.
X + represents a counter cation.
However, formula (81) has at least two crosslinking groups. )
The composition according to claim 1, further comprising a polymer having an arylamine structure represented by the following formula (50) as a repeating unit and a crosslinking group.

(In formula (50),
Ar 51 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected;
Ar 52 is at least one selected from the group consisting of a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group. It represents a divalent group in which one group is connected to a plurality of groups directly or via a linking group.
Ar 51 and Ar 52 may form a ring via a single bond or a connecting group.
Ar 51 and Ar 52 may have a substituent. )
An arylamine compound represented by any of the formulas (3-1) to (3-4), an electron-accepting compound represented by the formula (81), and an arylamine represented by the formula (50) The composition according to claim 2, wherein the polymer having the structure as a repeating unit each independently has a crosslinking group selected from formulas (X1) to (X17) in the following crosslinking group group T.
<Bridging group group T>

(In formulas (X1) to (X17), Q represents a direct bond or a connecting group.
* represents the bonding position.
R 110 in formula (X3), formula (X4), formula (X5) and formula (X9) represents a hydrogen atom or an alkyl group which may have a substituent.
In formulas (X1) to (X3), the benzene ring and naphthalene ring may have a substituent.
Further, the substituents may be bonded to each other to form a ring.
In formula (X1) and formula (X2), the cyclobutene ring may have a substituent. )
The composition according to claim 3, wherein the crosslinking group is one of the formulas (X1) to (X3).
The composition according to any one of claims 2 to 4, wherein the repeating unit represented by the formula (50) is a repeating unit represented by the following formula (54).

(In formula (54),
Ar 51 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected;
X is -C(R 207 )(R 208 )-, -N(R 209 )- or -C(R 211 )(R 212 )-C(R 213 )(R 214 )-,
R 201 , R 202 , R 221 and R 222 are each independently an alkyl group which may have a substituent,
R 207 to R 209 and R 211 to R 214 each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a hydrogen atom, an aralkyl group that may have a substituent, or is an aromatic hydrocarbon group which may be
a and b are each independently an integer of 0 to 4,
c is an integer from 0 to 3,
d is an integer from 0 to 4,
i and j are each independently an integer of 0 to 3. )
None of Ar 2 , Ar 3 , Ar 51 , Ar 52 , R 1 , R 2 , R 201 , R 202 , R 221 , R 222 , R 207 to R 209 , R 211 to R 214 has a substituent, The composition according to claim 5.
The composition according to any one of claims 1 to 6, further comprising a solvent.
A method for producing an organic electroluminescent device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer being formed using the composition according to claim 7. A method for manufacturing an organic electroluminescent device, including a step of forming it by a wet film forming method.
The method for manufacturing an organic electroluminescent device according to claim 8, wherein the organic layer is an organic layer between the anode and the light emitting layer.
An organic electroluminescent element having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer having the following formulas (3-1) to (3-4). An organic electroluminescent device containing a crosslinking reaction product of an arylamine compound represented by any of the above and an electron-accepting compound represented by the following formula (81).

(In formulas (3-1) to (3-4),
Ar 2 and Ar 3 are each independently one of formulas (4-1) to (4-3),
Each of the plurality of R 2 is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a2 are each independently 0 or 1,
Each of the plurality of A 2 's independently represents a hydrogen atom or a crosslinking group. )

(In formulas (4-1) to (4-3),
* represents the bonding position,
Each of the plurality of R 1 is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a1 are each independently 0 or 1,
Each of the plurality of A 1 's independently represents a hydrogen atom or a crosslinking group.
However, at least one of the group consisting of all A1 is the above-mentioned crosslinking group. )

(In formula (81), 5 R 81 , 5 R 82 , 5 R 83 , and 5 R 84 are each independent, and R 81 to R 84 are each independently a hydrogen atom, a heavy Hydrogen atom, halogen atom, aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, fluorine substitution an alkyl group having 1 to 12 carbon atoms, or a crosslinking group.
Ph 1 , Ph 2 , Ph 3 , and Ph 4 are symbols indicating respective benzene rings.
X + represents a counter cation.
However, formula (81) has at least two crosslinking groups. )
An organic electroluminescent element having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer having the following formulas (3-1) to (3-4). An organic electroluminescent device comprising a crosslinking reaction product of an arylamine compound represented by any of the above and a polymer having an arylamine structure represented by the following formula (50) as a repeating unit and a crosslinking group. .

(In formulas (3-1) to (3-4),
Ar 2 and Ar 3 are each independently one of formulas (4-1) to (4-3),
Each of the plurality of R 2 is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a2 are each independently 0 or 1,
Each of the plurality of A 2 's independently represents a hydrogen atom or a crosslinking group. )

(In formulas (4-1) to (4-3),
* represents the bonding position,
Each of the plurality of R 1 is independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent,
The plurality of a1 are each independently 0 or 1,
Each of the plurality of A 1 's independently represents a hydrogen atom or a crosslinking group.
However, at least one of the group consisting of all A1 is the above-mentioned crosslinking group. )

(In formula (50),
Ar 51 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group in which a plurality of groups selected from an aromatic hydrocarbon group and an aromatic heterocyclic group are connected;
Ar 52 is at least one selected from the group consisting of a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group. It represents a divalent group in which one group is connected to a plurality of groups directly or via a linking group.
Ar 51 and Ar 52 may form a ring via a single bond or a connecting group.
Ar 51 and Ar 52 may have a substituent. )
The organic electroluminescent device according to claim 11, wherein none of Ar2 , Ar3 , Ar51 , Ar52 , R1 , and R2 has a substituent.
An organic electroluminescent device manufactured by the method for manufacturing an organic electroluminescent device according to claim 8 or 9.
A display device comprising the organic electroluminescent element according to any one of claims 10 to 13.
A lighting device comprising the organic electroluminescent element according to any one of claims 10 to 13.