WO2023163001A1

WO2023163001A1 - Composition, organic electroluminescent element and method for producing same, display device, and lighting device

Info

Publication number: WO2023163001A1
Application number: PCT/JP2023/006325
Authority: WO
Inventors: 延軍李; 大輔弘; 一毅岡部
Original assignee: 三菱ケミカル株式会社
Priority date: 2022-02-24
Filing date: 2023-02-21
Publication date: 2023-08-31
Also published as: TW202348685A

Abstract

The present invention relates to a composition that comprises: a polymer compound having a repeat unit given by formula (1), having possibly substituted fluorene in the main chain and/or in side chain position, and having a crosslinking group; and an electron-accepting compound given by formula (81) and having a crosslinking group. (In formula (1) and formula (81), Ar1, G, *, Ar2, m, n, R81 to R84, Ph1 to Ph4, and X+ each have the definitions provided in the Description.)

Description

COMPOSITION, ORGANIC ELECTROLUMINESCENT DEVICE AND MANUFACTURING METHOD THEREOF, DISPLAY DEVICE, AND LIGHTING DEVICE

The present invention relates to a composition, an organic electroluminescent element and its manufacturing method, a display device, and a lighting device.

In recent years, as thin-film electroluminescent elements, instead of those using inorganic materials, organic electroluminescent elements using organic thin films have been developed. An organic electroluminescent device (OLED) usually has 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. Emission colors are also being developed into red, green, and blue. In recent years, quantum dot light-emitting devices using "quantum dots", which are inorganic light-emitting substances, in the light-emitting layer of organic electroluminescence devices have also been developed.

Methods for forming the organic layer of the organic electroluminescence device include a vacuum deposition method and a wet film forming method (coating method). The vacuum vapor deposition method facilitates lamination, and thus has the advantage of improving charge injection from the anode and/or cathode and facilitating confinement of excitons in the light-emitting layer. On the other hand, the wet film-forming method does not require a vacuum process and can easily be applied to a large area. There is an advantage that a layer containing the material can be formed. Therefore, in recent years, research and development of organic electroluminescence elements by film formation by a coating method have been vigorously carried out.

Patent Document 1 discloses an organic electroluminescence device having a composition containing an arylamine polymer compound containing a cross-linking group and an electron-accepting compound. Patent Document 2, Patent Document 3, and Patent Document 4 disclose an organic electroluminescence device having a composition containing a fluorine-containing arylamine polymer compound and an electron-accepting compound.

WO2017/164268 WO2020/065920 Japanese Patent Application Laid-Open No. 2020-115554 WO2020/217520

In general, an arylamine organic electron donor and an organic electron acceptor are mixed in an appropriate ratio, and when the N atoms of the arylamine partially form an ionic complex with the organic electron acceptor, this ionic complex The formation of a lowers the hole injection barrier from the anode, so materials that form stable ionic complexes are attracting attention. Patent Literature 1 discloses that this technique was used to successfully reduce the hole injection barrier. However, in the arylamine polymer compound disclosed in Patent Document 1, the HOMO (Highest Occupied Molecular Orbital) of the molecule is shallow, and a charge injection barrier is formed in the hole transport layer using a hole transport material with a deep HOMO. Therefore, the driving voltage of the organic electroluminescence device is insufficiently reduced. In the materials and techniques disclosed in Patent Documents 2 to 4, an ion complex is formed from an organic electron donor of an arylamine polymer compound having fluorine and an organic electron acceptor. However, although the film of the charge injection layer containing this ion complex is formed, the reduction of the driving voltage of the organic electroluminescence device is insufficient. In addition, an organic electron acceptor that does not contain a cross-linking group is used as a photopolymerization initiator, and the diffusion of the organic electron acceptor to the light-emitting layer is not sufficiently prevented, and the luminous efficiency and driving life cannot be improved. Ta.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a composition for obtaining an organic electroluminescent device having a low driving voltage, a high luminous efficiency, and a long driving life. .

As a result of extensive studies, the present inventors have found that a hole injection layer and/or a hole transport layer containing a cross-linking reaction product of an arylamine polymer compound with a specific structure and an electron-accepting compound with a specific structure can be used. Therefore, the inventors have found that the above problems can be solved in an organic electroluminescence device (OLED) or a quantum dot light-emitting device containing quantum dots in the light-emitting layer of the organic electroluminescence device, and have completed the present invention.

That is, the gist of the present invention is as follows in aspects 1 to 19.

Aspect 1 of the present invention has a repeating unit represented by the following formula (1), has a fluorene which may have a substituent in at least one of the main chain and the side chain, and has a cross-linking group. A composition comprising a polymer compound and an electron-accepting compound having a cross-linking group represented by the following formula (81).

(In formula (1),
Ar ¹ is an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, or an optionally substituted divalent aromatic heterocyclic ring having 3 to 50 carbon atoms. or a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group ,
G represents a divalent group represented by any one of formulas (1-1) to (1-3),
"*" represents the bonding position with the adjacent structure,
Each substituent A is independently a fluorine atom, _CF3 , or _SF5 .
Ar ² is a hydrogen atom, a substituent A, an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heteroaromatic group having 3 to 50 carbon atoms. A plurality of groups selected from a cyclic group, an optionally substituted aromatic hydrocarbon group, and an optionally substituted aromatic heterocyclic group are linked directly or via a linking group. represents a monovalent group,
m is an integer from 1 to 4,
n is an integer of 1-6. )

(In formula (81),
5 R ⁸¹ , 5 R ⁸² , 5 R ⁸³ and 5 R ⁸⁴ are each independently, and R ⁸¹ to R ⁸⁴ are each independently hydrogen atom, deuterium atom, halogen atom, optionally substituted aromatic hydrocarbon group having 6 to 50 carbon atoms, aromatic heterocyclic group having 3 to 50 carbon atoms optionally having substituent(s), fluorine-substituted 1 to 1 carbon atoms 12 alkyl groups or bridging groups.
Ph ¹ , Ph ² , Ph ³ and Ph ⁴ are symbols indicating respective benzene rings.
X ⁺ represents a counter cation. )

Aspect 2 of the present invention is the composition according to Aspect 1, comprising the electron-accepting compound represented by the formula (81) having at least two cross-linking groups.

Aspect 3 of the present invention is Aspect 1, wherein the compound represented by the formula (1) and the compound represented by the formula (81) each independently have a cross-linking group selected from the following cross-linking group group T: or a composition according to 2.
<Crosslinking Group T>

(In the above formula,
Q represents a direct bond or a linking group.
"*" represents the binding position.
R ¹¹⁰ in formula (X4), formula (X5), formula (X6) and formula (X10) represents a hydrogen atom or an optionally substituted alkyl group.
In formulas (X1) to (X4), the benzene ring and naphthalene ring may have a substituent. Also, the substituents may be combined with each other to form a ring.
In formulas (X1) and (X2), the cyclobutene ring may have a substituent. )

Aspect 4 of the present invention is the composition according to any one of Aspects 1 to 3, wherein said G is represented by any of the following formulas.

(In the above formula, "*" represents the bonding position with the adjacent structure.)

Aspect 5 of the present invention is the composition according to any one of Aspects 1 to 3, wherein [-G-Ar ² ] is represented by any one of the following formulas.

In aspect 6 of the present invention, Ar ¹ has one partial structure selected from the following formulas (2-1) to (2-3), or the following formulas (2-1) to (2- 3) having a bonding structure in which two or more selected from the following formulas (2-1) to (2-3) are bonded to each other, and the bonding structure bonds two or more structures of at least one type selected from the following formulas (2-1) to (2-3) 6. The composition of any one of aspects 1-5, which may contain a structure comprising:

(In each of the above formulas (2-1) to (2-3), R ¹ and R ² each independently represent a hydrogen atom, a deuterium atom, a halogen atom, or an optionally substituted carbon number of 6 ~18 aromatic hydrocarbon groups, optionally substituted C3-C12 aromatic heterocyclic groups, C1-C12 alkyl groups, and "*" with the adjacent structure represents the binding position.)

Aspect 7 of the present invention is the composition according to any one of Aspects 1 to 6, wherein the polymer compound further has a repeating unit represented by the following formula (3).

(In the above formula (3), Ar ³ is an optionally substituted 2-fluorenyl group. Ar ⁴ is an optionally substituted divalent aromatic hydrocarbon group, A divalent aromatic heterocyclic group which may have a substituent, or a divalent aromatic hydrocarbon group which may have a substituent and a divalent which may have a substituent represents a divalent group in which at least two groups selected from the group consisting of aromatic heterocyclic groups are linked directly or via a linking group.)

Aspect 8 of the present invention is the composition according to any one of aspects 1 to 7, further comprising a solvent.

Aspect 9 of the present invention is a method for manufacturing an organic electroluminescence 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 the A method for producing an organic electroluminescence device, comprising a step of forming by a wet film-forming method using the composition of

A tenth aspect of the present invention is the method for producing an organic electroluminescent device according to Aspect 9, wherein the organic layer is an organic layer between the anode and the light-emitting layer.

Embodiment 11 of the present invention is an organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,
The organic layer has a repeating unit represented by the following formula (1), has fluorene which may have a substituent in at least one of the main chain and the side chain, and has a cross-linking group. An organic electroluminescence device containing a cross-linking reaction product of a compound and an electron-accepting compound having a cross-linking group represented by the following formula (81).

(In formula (1),
Ar ¹ is an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, or an optionally substituted divalent aromatic heterocyclic ring having 3 to 50 carbon atoms. or a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group ,
G represents a divalent group represented by any one of formulas (1-1) to (1-3),
"*" represents the binding site with the adjacent structure,
Each substituent A is independently a fluorine atom, _CF3 , or _SF5 .
Ar ² is a hydrogen atom, a substituent A, an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heteroaromatic group having 3 to 50 carbon atoms. A plurality of groups selected from a cyclic group, an optionally substituted aromatic hydrocarbon group, and an optionally substituted aromatic heterocyclic group are linked directly or via a linking group. represents a monovalent group,
m is an integer from 1 to 4,
n is an integer of 1-6. )

Aspect 12 of the present invention is the organic electroluminescence device according to Aspect 11, wherein the G is represented by any one of the following formulas.

Aspect 13 of the present invention is the organic electroluminescence device according to Aspect 11, wherein [-G-Ar ² ] is represented by any one of the following formulas.

In embodiment 14 of the present invention, Ar ¹ has one partial structure selected from the following formulas (2-1) to (2-3), or the following formulas (2-1) to (2- 3) having a bonding structure in which two or more selected from the following formulas (2-1) to (2-3) are bonded to each other, and the bonding structure bonds two or more structures of at least one type selected from the following formulas (2-1) to (2-3) 14. The organic electroluminescent device according to any one of aspects 11 to 13, which may contain a structure with

(In each of the above formulas (2-1) to (2-3), R ¹ and R ² are each independently a hydrogen atom, a deuterium atom, a halogen atom, or the number of carbon atoms which may have a substituent. an aromatic hydrocarbon group of 6 to 18, an aromatic heterocyclic group of 3 to 12 carbon atoms which may have a substituent, an alkyl group of 1 to 12 carbon atoms, and * is a bond with an adjacent structure position.)

Aspect 15 of the present invention is the organic electroluminescence device according to any one of Aspects 11 to 14, wherein the polymer compound further has a repeating unit represented by the following formula (3).

(In formula (3), Ar ³ is an optionally substituted 2-fluorenyl group. Ar ⁴ is an optionally substituted divalent aromatic hydrocarbon group, a substituted a divalent aromatic heterocyclic group optionally having a group, or a divalent aromatic hydrocarbon group optionally having a substituent and a divalent It represents a divalent group in which at least two groups selected from the group consisting of aromatic heterocyclic groups are linked directly or via a linking group.)

A sixteenth aspect of the present invention is an organic electroluminescent device manufactured by the method for manufacturing an organic electroluminescent device according to the ninth or tenth aspect.

Aspect 17 of the present invention is the organic electroluminescent device according to any one of Aspects 11 to 16, which contains quantum dots in the light-emitting layer.

Aspect 18 of the present invention is a display device comprising the organic electroluminescent element according to any one of Aspects 11 to 17.

A nineteenth aspect of the present invention is a lighting device comprising the organic electroluminescent element according to any one of aspects 11 to 17.

The composition of the present invention can provide an organic electroluminescent device with low driving voltage, high luminous efficiency, and long driving life.

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

In the following, embodiments of the composition, the organic electroluminescence device and its manufacturing method, the display device, and the lighting device, which are one embodiment of the present invention, will be described in detail. Although the following description is a first embodiment which is an example (representative example) of embodiments of the present invention, the present invention is not specified by these contents unless it exceeds the gist thereof.

In the present invention, "optionally having a substituent" means that it may have one or more substituents.

[definition]
Hereinafter, in describing in detail the structures of the fluorine-containing arylamine polymer compound, the electron-accepting compound having a cross-linking group, and the charge-transporting polymer compound used in the present invention, common partial structures are as follows unless otherwise specified. , with the following structure:

<Aromatic hydrocarbon group>
The aromatic hydrocarbon group refers to a monovalent, divalent, or trivalent or higher aromatic hydrocarbon ring structure depending on the bonding state in the structure of the compound to be described later.

In the structure of the aromatic hydrocarbon ring, the number of carbon atoms is usually not limited, but preferably 6 or more and 60 or less, and the upper limit of the carbon number is more preferably 48 or less, more preferably 48 or less. It has 30 or less carbon atoms. Specifically, six-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, and fluorene ring. A monocyclic or 2 to 5 condensed ring group, or a structure in which a plurality of groups selected from these are linked together may be mentioned. When a plurality of aromatic hydrocarbon rings are linked, a structure in which 2 to 10 rings are linked is usually mentioned, and a structure in which 2 to 5 rings are linked is preferable. When a plurality of aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.

Preferred aromatic hydrocarbon ring structures include a benzene ring, a biphenyl ring, i.e., a structure in which two benzene rings are linked, a terphenyl ring, i.e., a structure in which three benzene rings are linked, a quaterphenylene ring, i.e., a structure in which four benzene rings are linked, and a naphthalene ring. , is a fluorene ring.

<Aromatic heterocyclic group>
The aromatic heterocyclic group refers to a monovalent, divalent, or trivalent or higher aromatic heterocyclic structure depending on the bonding state in the structure of the compound to be described later.

In the structure of the aromatic heterocyclic ring, the number of carbon atoms is generally not limited, but preferably 3 or more and 60 or less, and more preferably 48 or less as the upper limit of the carbon number, more preferably 48 or less. It has 30 or less carbon atoms. 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, benzoisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring , a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, a 5- to 6-membered monocyclic ring or a 2- to 4-condensed divalent group or A group in which a plurality of these are linked is exemplified. When a plurality of aromatic heterocycles are linked, the same structure may be linked, or different structures may be linked. When a plurality of aromatic heterocycles are linked, a structure in which 2 to 10 are linked is usually mentioned, and a structure in which 2 to 5 are linked is preferable.

The aromatic heterocyclic ring structure is preferably a thiophene ring, a benzothiophene ring, a pyrimidine ring, a triazine ring, a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring.

<Substituent>
Unless otherwise specified, the substituent is an arbitrary group, preferably a group selected from the following substituent group Z and a bridging group. In addition, when it is described that the substituent that may be present is selected from Substituent Group Z, preferred substituents are also as described in Substituent Group Z below.

<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, A group consisting of haloalkyl groups, alkylthio groups, arylthio groups, silyl groups, siloxy groups, cyano groups, aromatic hydrocarbon groups and aromatic heterocyclic groups. These substituents may contain any structure of linear, branched and cyclic.

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

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

Among the above substituent groups Z, alkyl groups, alkoxy groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups are preferred.

Further, each substituent in the substituent group Z may further have a substituent. Examples of these substituents include the same as those in the above-mentioned substituent group Z or a bridging group. Preferably, it has no further substituents, or an alkyl group with up to 8 carbon atoms, an alkoxy group with up to 8 carbon atoms, or a phenyl group, more preferably an alkyl group with up to 6 carbon atoms, or an alkoxy group with up to 6 carbon atoms. or a phenyl group. From the viewpoint of charge transport properties, it is more preferable not to have additional substituents.

When the substituent that each substituent of the substituent group Z may further have is a crosslinkable group, the crosslinkable group is preferably a crosslinkable group selected from the following crosslinkable group T. A substituent that preferably further has a bridging group is an alkyl group or an aromatic hydrocarbon group.

<Crosslinking group>
Here, the cross-linking group means a group that reacts with other cross-linking groups located in the vicinity of the cross-linking group by irradiation with heat and/or active energy rays to form a new chemical bond. In this case, the reactive group may be the same group as the bridging group or a different group.

Examples of cross-linking groups include, but are not limited to, alkenyl group-containing groups, conjugated diene structure-containing groups, alkynyl group-containing groups, oxirane structure-containing groups, oxetane structure-containing groups, aziridine structure-containing groups, azide groups, anhydrous Examples thereof 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. As specific examples of preferred cross-linking groups, cross-linking groups represented by any one of the following formulas (X1) to (X18) in the following cross-linking group group T are preferable.

(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 generally an alkylene group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms.
The divalent aromatic hydrocarbon group usually has 6 or more carbon atoms and usually 36 or less carbon atoms, preferably 30 or less, more preferably 24 or less, and the aromatic hydrocarbon ring structure is benzene A ring is preferred, and the substituents which may be present can be selected from the substituent group Z described above.

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 still more preferably 8 or less.

The benzene ring and naphthalene ring of formulas (X1) to (X4) and the substituents that R ¹¹⁰ of formulas (X4) to (X6) and (X10) may have are preferably an alkyl group and an aromatic They are a hydrocarbon group, an alkyloxy group and an aralkyl group.

The alkyl group as a substituent has a linear, branched or cyclic structure, and preferably has 24 or less carbon atoms, more preferably 12 or less carbon atoms, still more preferably 8 or less carbon atoms, and preferably 1 or more carbon atoms.

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 aforementioned 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, still 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 aforementioned alkyl group as a substituent.

The substituent that the cyclobutene ring of formulas (X1) and (X2) may have is preferably an alkyl group.

R ¹¹⁰ in formula (X4) is preferably a hydrogen atom or an unsubstituted alkyl group. R ¹¹⁰ in formulas (X5), (X6) and (X10) is preferably an optionally substituted alkyl group, more preferably an unsubstituted alkyl group.

As the cross-linking group, a cross-linking group represented by any one of the formulas (X1) to (X3) is preferable because the cross-linking reaction proceeds only with heat, the polarity is small, and the effect on charge transport is small.

In the bridging group represented by formula (X1), the cyclobutene ring is opened by heat, and the ring-opened groups bond to each other to form a bridging structure, as shown in the following formula. In the following description, the linking group Q in formulas (X1) to (X4) and the like is omitted.

As shown in the following formula, the cyclobutene ring of the bridging group represented by formula (X2) is opened by heat, and the ring-opened groups bond to each other to form a bridging structure.

As shown in the following formula, the cyclobutene ring of the bridging group represented by formula (X3) is opened by heat, and the ring-opened groups bond to each other to form a bridging structure.

In the bridging group represented by any one of formulas (X1) to (X3), the cyclobutene ring is opened by heat, and the ring-opened group reacts with the double bond when a double bond exists nearby. to form a crosslinked structure.

An example in which the cross-linking group represented by formula (X1) and the cross-linking group represented by formula (X4) having a double bond site form a cross-linked structure is shown below.

The group containing a double bond capable of reacting with the cross-linking group represented by any one of formulas (X1) to (X3) includes, in addition to the cross-linking group represented by formula (X4), formula (X5), A cross-linking group represented by any one of formula (X6), formula (X12), formula (X15), formula (X16), formula (X17) and formula (X18) can be mentioned. When a group containing these double bonds is used as a cross-linking group in an electron-accepting compound, other components forming a hole-injecting layer and/or a hole-transporting layer, such as a hole-transporting compound, are added with the formula (X1 ) to (X3) is preferable because the possibility of forming a crosslinked structure increases.

As the cross-linking group, a radically polymerizable cross-linking group represented by any one of the formulas (X4), (X5), and (X6) is preferred because it has a low polarity and does not easily interfere with charge transport.

As the cross-linking group, the cross-linking group represented by the formula (X7) is preferable from the viewpoint of enhancing the electron-accepting property. When the cross-linking group represented by formula (X7) is used, the following cross-linking reaction proceeds.

A cross-linking group represented by either formula (X8) or formula (X9) is preferable in terms of high reactivity. When the cross-linking group represented by formula (X8) and the cross-linking group represented by formula (X9) are used, the following cross-linking reaction proceeds.

As the cross-linking group, a cationic polymerizable cross-linking group represented by any one of the formula (X10), the formula (X11), and the formula (X12) is preferable because of its high reactivity.

<Charge transport material>
A charge transport material used in the present invention is a material capable of transporting holes and/or electrons. Further, the charge transport material used in the present invention is preferably a material that transports holes and is oxidized by an electron-accepting compound to form a cation radical. In the present invention, the charge-transporting material is preferably a polymer compound, preferably a hole-transporting polymer compound, and preferably a polymer compound containing an arylamine structure as a repeating unit. In this case, the charge is usually holes, the charge transport is the transport of holes, the charge transport film is the hole transport film, and the charge injection layer is the hole injection layer.

[Composition of the present invention]
The composition of the present invention has a repeating unit represented by the following formula (1), has a fluorene which may have a substituent in at least one of the main chain and the side chain, and has a cross-linking group. A polymer compound (hereinafter sometimes referred to as "the fluorine-containing arylamine polymer compound of the present invention"), and an electron-accepting compound having a cross-linking group represented by the following formula (81) (hereinafter, " It is a composition containing the "electron-accepting compound of the present invention".

The composition of the present invention comprises a polymer compound having a repeating unit represented by the following formula (1) and having a cross-linking group, and an electron acceptor having at least two cross-linking groups represented by the following formula (81). It may be a composition containing a sexual compound.

(In formula (1),
Ar ¹ is an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, or an optionally substituted divalent aromatic heterocyclic ring having 3 to 50 carbon atoms. or a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group ,
G represents a divalent group represented by any one of formulas (1-1) to (1-3),
Each substituent A is independently a fluorine atom, _CF3 , or _SF5 .
Ar ² is a substituent A, an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heterocyclic group having 3 to 50 carbon atoms, or a monovalent group selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group linked directly or via a linking group. represents the group,
m is an integer from 1 to 4,
n is an integer of 1-6. )

<Polymer compound having a cross-linking group>
The polymer compound having a cross-linking group is preferably a polymer compound having a cross-linking group and having a repeating unit represented by the above formula (1) and containing an arylamine structure as a repeating unit. This polymer compound is included as a charge transport material in the composition of the present invention.

(Ar ¹ )
The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-60, more preferably 6-30, still more preferably 6-18. Specific examples of aromatic hydrocarbon groups include benzene ring, naphthalene ring, fluorene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzanthracene ring, or perylene ring. is usually 6 or more, usually 30 or less, preferably 18 or less, more preferably 14 or less divalent group of aromatic hydrocarbon ring structure, or a plurality of structures selected from these structures are chained or A divalent group having a branched and bonded structure can be mentioned. When a plurality of aromatic hydrocarbon rings are linked, a structure in which 2 to 8 rings are linked is usually mentioned, and a structure in which 2 to 5 rings are linked is preferable. When a plurality of aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.

The number of carbon atoms in the aromatic heterocyclic group is preferably 3-50, more preferably 3-30, still more preferably 3-18. Specific examples of the aromatic heterocyclic group include triazine ring, pyrimidine ring, pyridine ring, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, carbazole ring, etc., having usually 3 or more, usually 30 or less, preferably 18 carbon atoms. Hereinafter, more preferably, a divalent group having an aromatic heterocyclic structure of 12 or less, or a divalent group having a structure in which a plurality of structures selected from these structures are bonded in a chain or branched manner. be done.

Ar ¹ is an optionally substituted divalent aromatic hydrocarbon having 6 to 60 carbon atoms, or an optionally substituted divalent aromatic heterohydrocarbon having 3 to 50 carbon atoms. A divalent group in which one or more groups selected from cyclic groups are bonded directly or via a linking group is preferable, and the hole transport property is improved. An aromatic hydrocarbon group which may have a substituent is preferred, and the aromatic hydrocarbon group preferably has 1 to 4 benzene rings, 1 or 2 naphthalene rings, 1 or 2 fluorene A divalent group formed by chaining or branching a plurality of structures selected from a ring, one or two phenanthrene rings, and one tetraphenylene ring in any order, or 1,4-phenylene group, 1,3-phenylene group, 2,7-fluorenylene group, divalent spirobisfluorene group, more preferably 1 to 4 benzene rings, and 1 or 2 A divalent group formed by binding a plurality of structures selected from fluorene rings in a chain or branched manner in any order, particularly preferably one or two phenylene groups, 2,7-fluorenylene a divalent group in which one or two phenylene groups are bonded in this order in a chain, a phenylene group, a biphenylene group, a p-terphenylene group, or a 2,7-fluorenylene group. The fluorene structure may have substituents at the 9 and 9′ positions, and the substituents that may have are preferably groups selected from the substituent group Z described above.

These aromatic hydrocarbon structures may have substituents. Substituents which may be present are as described above, and specifically can be selected from the substituent group Z. Preferred substituents are the preferred substituents of the substituent group Z described above.

(Preferred range of Ar ¹ )
Ar ¹ preferably has at least one structure selected from the following formulas (2-1) to (2-7) from the viewpoint of the solubility and durability of the polymer compound.

In each of the above formulas (2-1) to (2-7), * represents a bond with an adjacent structure or a hydrogen atom, and at least one of the two * represents a bonding position with an adjacent structure, At least one of two arbitrary * selected from four * represents a binding position to an adjacent structure. In the following description, the definition of * is the same unless otherwise specified. R ¹ and R ² each independently represent a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or an optionally substituted It is preferably an aromatic heterocyclic group having 3 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms.

Ar ¹ has one partial structure selected from the above formulas (2-1) to (2-3), or two or more selected from the above formulas (2-1) to (2-3) are bonded to each other, and the bonding structure contains a structure in which two or more of at least one structure selected from the above formulas (2-1) to (2-3) are bonded good too.

That is, the bond structure may include, for example, a structure in which two or more structures of (2-1) above are bonded.

(R ¹ , R ² )
R ¹ and R ² each independently represent a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituent an aromatic heterocyclic group having 3 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms, preferably an alkyl group having 6 to 12 carbon atoms, an alkenyl group, an alkynyl group, an alkoxy group, and an aryl group. an oxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aralkyl group, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms; and R ¹ and R ² may combine together to form a ring. As the aromatic hydrocarbon ring structure, a phenyl group or a group in which a plurality of phenyl groups are linked is more preferable.

These groups may have substituents. The substituents that may be present are as described above, and specifically, they can be selected from the substituent group Z or the bridging group. Preferably, it is a preferable substituent of the substituent group Z, an aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a cross-linking group, or a cross-linking group.

The partial structure is more preferably a structure selected from formulas (2-1) to (2-7), more preferably a structure selected from formulas (2-1) to (2-5), Structures selected from formulas (2-1) to (2-4) are particularly preferred. It is most preferable to have partial structures represented by formulas (2-2) and (2-3) because of their excellent charge transport properties.

　Formula (2-1) is preferably a 1,3-phenylene group or a 1,4-phenylene group.

Formula (2-2) is preferably the following formula (2-2-2).

Formula (2-2) is more preferably formula (2-2-3) below.

Ar ¹ preferably has a partial structure represented by formula (2-1) and a partial structure represented by formula (2-2) from the viewpoint of compound solubility and durability.

As the partial structure having the partial structure represented by formula (2-1) and the partial structure represented by formula (2-2), the partial structure represented by formula (2-1) and the partial structure represented by formula (2-2 A partial structure represented by at least one selected from the following formulas (2-8) to (2-11), which is a structure containing a plurality of structures selected from the partial structures represented by ), is more preferable. .

As the partial structure having the partial structure represented by formula (2-1) and the partial structures represented by formulas (2-3) and (2-4), the partial structure represented by formula (2-1) and a structure including a plurality of structures selected from partial structures represented by formulas (2-3) and (2-4), selected from the following formulas (2-12) to (2-15) A partial structure represented by at least one is more preferable.

(G)
G represents a divalent group represented by any one of the above formulas (1-1) to (1-3), and each substituent A is independently a fluorine atom, CF ₃ , or SF ₅ be.
Among the above, the substituent A is preferably a fluorine atom or CF3 from the viewpoint of not reducing the charge transport ability. From the same point of view, m and n in formulas (1-1) to (1-3) are preferably integers of 1-2.

G is preferably a group represented by any of the following formulas.

( ^Ar2 )
Ar ² is a hydrogen atom, a substituent A, an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heteroaromatic group having 3 to 50 carbon atoms. A plurality of groups selected from a cyclic group, an optionally substituted aromatic hydrocarbon group, and an optionally substituted aromatic heterocyclic group are linked directly or via a linking group. represents a monovalent group.

In the polymer compound used in the present invention, when a plurality of Ar ² are present, the plurality of Ar ² may be the same or different.

Specific examples of monovalent aromatic hydrocarbon groups include benzene ring, azulene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring and acenaphthene. 6-membered monocyclic or 2-5 condensed monovalent groups such as ring, fluoranthene ring, and fluorene ring.

Specific examples of monovalent aromatic heterocyclic groups include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrrolo imidazole 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, 5- or 6-membered monocyclic ring or 2-4 condensed ring such as pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, phenanthridine ring, perimidine ring, quinazoline ring, quinazolinone ring, etc. valence groups.

The linking group includes, for example, an oxygen atom or a carbonyl group. Since the triplet level can be increased by constructing a non-conjugated structure with an aromatic ring, a structure in which phenylene rings are linked by an oxygen atom or a carbonyl group can also be used. A structure in which they are directly linked without a linking group is preferred. The same applies to the linking group in Ar ¹ .

Among these, from the viewpoint of excellent charge transportability and excellent durability, a monovalent aromatic hydrocarbon group is preferable, a monovalent group of a benzene ring or a fluorene ring is more preferable, and a phenyl group or a fluorenyl group is further preferable. A fluorenyl group is particularly preferred, and a 2-fluorenyl group is most preferred.

Ar ² is preferably a fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms from the viewpoint of solubility in a coating solvent, and a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms. Especially preferred. Furthermore, Ar ² is preferably a 9-alkyl-2-fluorenyl group in which a 2-fluorenyl group is substituted with an alkyl group at the 9-position, and particularly a 9,9-dialkyl-2-fluorenyl group in which an alkyl group is disubstituted. preferable. Ar ² is preferably a fluorenyl group substituted with an alkyl group, because the solubility in a solvent is improved.

A monovalent group in which a plurality of groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked directly or via a linking group As can be used a monovalent group in which a plurality of groups selected from the aromatic hydrocarbon group and the aromatic heterocyclic group are linked directly or via a linking group.

(-G- ^Ar2 )
[-G-Ar ² ] is preferably a group represented by any one of the following formulae.

(Concrete example)
Specific examples of the repeating unit represented by formula (1) used in the present invention are shown below, but the invention is not limited thereto.

<Fluorene which may have a substituent>
A polymer compound having a cross-linking group has fluorene which may have a substituent in at least one of the main chain and the side chain.
The above substituent is preferably a linear or branched alkyl group having 1 to 12 carbon atoms. The above substituents are preferably introduced into the 5-membered ring portion of fluorene. Examples of the polymer compound having fluorene in which the substituent is introduced into the 5-membered ring portion include polymer compound P-1 described later.

<Arylamine structure which is a preferred repeating unit to be combined with the repeating unit represented by formula (1) used in the present invention>
The repeating unit of the arylamine structure of the polymer compound having the preferable arylamine structure as a repeating unit, which is combined with the repeating unit represented by the above formula (1) used in the present invention, is represented by the following formula (50).

(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 linked, and Ar ⁵² represents a divalent aromatic At least one group selected from the group consisting of a hydrocarbon group, a divalent aromatic heterocyclic group, or the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is directly or a linking group represents a divalent group in which a plurality of groups are linked via
Ar ⁵¹ and Ar ⁵² may form a ring via a single bond or a linking group.
Ar ⁵¹ and Ar ⁵² may have a substituent. )

The substituent that Ar ⁵¹ and Ar ⁵² may have is preferably a substituent selected from the substituent group Z or a cross-linking group.

When Ar ⁵¹ and Ar ⁵² have a cross-linking group, the cross-linking group is preferably a cross-linking group selected from the above-described cross-linking group T.

The substituents that the aromatic hydrocarbon group and aromatic heterocyclic group of Ar ⁵¹ may have are not particularly limited as long as they do not significantly reduce the properties of the polymer compound used in the present invention. The substituent is preferably a group selected from the group Z of substituents described below, more preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, and still more preferably an alkyl group.

Ar ⁵¹ is preferably a fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms, particularly preferably a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms, from the viewpoint of solubility in a solvent. . 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 is substituted with an alkyl group is particularly preferred.

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

Ar ⁵¹ is also preferably a spirobifluorenyl group from the viewpoint of solubility in solvents.

Examples of the repeating unit represented by the formula (50) include repeating units represented by the following formula (3).

Further, as the polymer containing the 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), 52) or a repeating unit that is a group represented by the following formula (53).

(In formula (51),
* represents a bond to the nitrogen atom of the main chain of formula (50),
Ar ⁵³ and Ar ⁵⁴ are each independently a divalent aromatic hydrocarbon group optionally having a substituent, an aromatic heterocyclic group optionally having a substituent, or having a substituent represents a divalent group in which a plurality of optionally substituted aromatic heterocyclic groups or aromatic hydrocarbon groups are linked directly or via a linking group,
Ar ⁵⁵ is an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, an optionally substituted aromatic hydrocarbon group or an aromatic represents a monovalent group in which multiple heterocyclic groups are linked 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 substituent that may be present is preferably a group selected from the above-described substituent group Z or a cross-linking group.

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

These groups may have a substituent. The substituent that may be present is preferably a group selected from the above-described substituent group Z or a cross-linking group. Preferably Ar ⁵³ has no substituents.

In addition, when a plurality of these divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked, it is preferably a group in which a plurality of linked divalent aromatic hydrocarbon groups are bonded so as not to be conjugated. Specifically, it preferably contains a 1,3-phenylene group or a group having a substituent and having a twisted structure due to the steric effect of the substituent, more preferably a 1,3- It is a group in which a plurality of phenylene groups or unsubstituted 1,3-phenylene groups are linked.

( ^Ar54 )
Ar ⁵⁴ is preferably a group in which one or more divalent aromatic hydrocarbon groups, which may be the same or different, are linked, and the divalent aromatic group hydrocarbon group may have a substituent. When multiple groups are linked, the number of linked groups is preferably 2 to 10, more preferably 6 or less, and particularly preferably 3 or less from the viewpoint of film stability. Preferred aromatic hydrocarbon ring structures are benzene ring, naphthalene ring, anthracene ring and fluorene ring, and more preferred are benzene ring and fluorene ring. A group in which 1 to 4 phenylene rings are linked or a group in which a phenylene ring and a fluorene ring are linked are preferable as the group in which a plurality of rings are linked. A biphenylene group in which two phenylene rings are linked is particularly preferable from the viewpoint of expanding LUMO.

These groups may have substituents. The substituent that may be present is preferably a group selected from the above-described substituent group Z or a cross-linking group. Preferred substituents are phenyl, naphthyl and fluorenyl groups. Moreover, it is also preferable not to have a substituent.

( ^Ar55 )
Ar ⁵⁵ is an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, an optionally substituted aromatic hydrocarbon group or A monovalent group in which a plurality of aromatic heterocyclic groups are linked 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 linked.

These groups may have substituents. The substituent that may be present is preferably a group selected from the above-described substituent group Z or a cross-linking group.

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

Ar ⁵⁵ preferably has a structure represented by any one of Schemes 2A, 2B and 2C below.

In Schemes 2A to 2C above, "-*" represents the binding position to Ar ⁵⁴ , and when there are multiple "-*"s, one of them represents the binding position to Ar ⁵⁴ .
These structures may have a substituent. The substituent that these structures may have is preferably a group or a cross-linking group selected from the substituent group Z, and when a cross-linking group is included, the cross-linking group is selected from the cross-linking group T groups are preferred.

(R ³¹ and R ³² )
Preferably, R ³¹ and R ³² in Schemes 2A and 2B are each independently an optionally substituted linear, branched or cyclic alkyl group. Although the number of carbon atoms in the alkyl group is not particularly limited, 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 more preferably a methyl group or an ethyl group. .

R ³¹ and R ³² may be the same or different, but all R ³¹ and R ³² are are preferably the same groups.

(Ar ^d18 )
Each Ar ^d18 in Scheme 2B is independently an aromatic hydrocarbon group or an aromatic heterocyclic group. Ar ^d18 is preferably an aromatic hydrocarbon group, more preferably a phenyl group, from the viewpoint of stability. These groups may further have a substituent. The substituent that may be present is preferably a group selected from the above-described substituent group Z or a cross-linking group.

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 spread 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 through e-4 are preferred. Furthermore, from the viewpoint of the effect of confining the excitons formed in the light-emitting layer, which have a higher 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, d-1 benzene ring structure, d-6 fluorene 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 9,9'-position may have a substituent, and the substituent that may have is preferably a group or a cross-linking group selected from the substituent group Z, and when having a cross-linking group, as a cross-linking group is preferably a group selected from the above-mentioned cross-linking group T. Among these substituents, an alkyl group is preferable.

( ^Ar56 )
Ar ⁵⁶ represents a hydrogen atom or a substituent. When Ar ⁵⁶ is a substituent, it is not particularly limited, but is preferably an aromatic hydrocarbon group, an aromatic heterocyclic group or a bridging group. It may have a substituent selected from group Z or a cross-linking group selected from group T of cross-linking groups. When Ar ⁵⁶ is a cross-linking group, it is preferably a cross-linking group selected from the cross-linking group T.

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

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

(Specific examples of groups represented by formula (51))
Specific examples of the group represented by formula (51) are shown below, but the group represented by formula (51) is not limited thereto.

(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 or aromatic heterocyclic groups optionally having a substituent are linked directly or via a linking group,
Ar ⁶³ to Ar ⁶⁵ are each independently a hydrogen atom or a substituent.
* represents the bonding position to the nitrogen atom of the main chain in formula (50). )

(Ar ⁶³ -Ar ⁶⁵ )
Ar ⁶³ to Ar ⁶⁵ are each independently the same as Ar ⁵⁶ above.
Ar ⁶³ to Ar ⁶⁴ are preferably hydrogen atoms.

( ^Ar62 )
Ar ⁶² is an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted divalent aromatic heterocyclic group, or optionally substituted It is a divalent group in which a plurality of aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group. Preferably, it is an optionally substituted divalent aromatic hydrocarbon group or a group in which a plurality of optionally substituted divalent aromatic hydrocarbon groups are linked. Here, the substituents which the aromatic hydrocarbon group may have and the substituents which the aromatic heterocyclic group may have are preferably the same groups as those in the substituent group Z or the bridging groups. As the cross-linking group, a group selected from the cross-linking group T is preferable.

A specific structure of Ar ⁶² is similar to that of Ar ⁵⁴ .

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

In these preferred structures of Ar ⁶² , the phenylene group preferably has no substituents other than the linking position so that Ar ⁶² is not twisted due to the steric effect of the substituents. Further, the fluorenylene group preferably has substituents at the 9 and 9′ positions from the viewpoint of improving solubility and durability of the fluorene structure. The substituent is preferably a substituent or a cross-linking group selected from the substituent group Z, and more preferably an alkyl group. These substituents may be further substituted with a bridging group. As the cross-linking group, a cross-linking group selected from the cross-linking group T is preferable. A substituent selected from the substituent group Z is preferable.

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

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

(In formula (53),
* represents a bond to the nitrogen atom of the main chain of formula (50),
Ar ⁷¹ represents a divalent aromatic hydrocarbon group,
Ar ⁷² and Ar ⁷³ are each independently 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 via a linking group. represents a monovalent group in which a plurality of are linked, 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 substituent that may be present is preferably a group selected from the substituent group Z or a cross-linking group. When it has a cross-linking group, the cross-linking group is preferably a group selected from the above-mentioned cross-linking group T.

^<Ar71>
Ar ⁷¹ is the same group as Ar ⁵³ above.

Ar ⁷¹ is particularly preferably a group in which 2 to 6 optionally substituted benzene rings are linked, and a quaterphenylene group in which 4 optionally substituted benzene rings are linked. Most preferred.

In addition, Ar ⁷¹ preferably contains at least one, more preferably two or more, benzene rings linked at the 1 and 3 positions, which are non-conjugated sites.

When Ar ⁷¹ is a group in which a plurality of optionally substituted divalent aromatic hydrocarbon groups are linked, from the viewpoint of charge transport property or durability, it is preferable that all of them are directly linked and linked. .

Therefore, preferred structures for Ar ⁷¹ connecting the nitrogen atom of the main chain of the polymer and the ring HA in the formula (53) are as shown in Schemes 2-1 and 2-2 below. be. "-*" represents the nitrogen atom of the main chain of the polymer or the bonding site with the 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 the ring HA.

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

< ^X2 and ^Y2 >
^X2 and ^Y2 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.

Both X ² and Y ² are preferably N atoms from the viewpoint of facilitating the localization of LUMO around ring HA.

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 as the substituent which may be possessed. From the viewpoint of charge transport properties, X ² and Y ² more preferably have no substituents.

<Ar ⁷² and Ar ⁷³ >
Ar ⁷² and Ar ⁷³ are each independently 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 via a linking group. is a monovalent group in which a plurality of groups are linked by These groups may have a substituent, and the substituent which may have is preferably a group selected from the substituent group Z or a bridging group. When it has a cross-linking group, the cross-linking group is preferably a group selected from the cross-linking group T described above.

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, 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 spread 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-5, d-1 to Structures selected from d-12, and e-1 through e-4 are preferred.

further selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4 from the viewpoint of the effect of confining excitons formed in the light-emitting layer, which have a higher triplet level Structure is preferred.

Structures selected from d-1 to d-12 and e-1 to e-4 are more preferred to prevent aggregation of molecules. Ar ⁷² =Ar ⁷³ =d-1 or d-10 is preferable from the viewpoint of easy synthesis and excellent stability, and a benzene ring structure of d-1 is particularly preferable.
Further, these structures may have substituents.

(Specific examples of groups represented by formula (53))
Specific examples of the group represented by formula (53) are shown below, but the group represented by formula (53) is not limited thereto.

(preferred repeating unit represented by 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).

(In formula (54),
Ar ⁵¹ is the same as Ar ⁵¹ in the formula (50),
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 optionally substituted alkyl group,
R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aralkyl group, or a substituent. an aromatic hydrocarbon group which may have
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 from 0 to 3; )

( ^R201 , ^R202 , ^R221 , ^R222 )
R ²⁰¹ , R ²⁰² , R ²²¹ and R ²²² in the repeating unit represented by formula (54) are each independently an optionally substituted alkyl group.

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

When there is a plurality of R ²⁰¹ , the plurality of R ²⁰¹ may be the same or different, and when there is a plurality of R ²⁰² , the plurality of R ²⁰² may be the same or different. All R ²⁰¹ and R ²⁰² are preferably the same group because the charge can be uniformly distributed around the nitrogen atom and the synthesis is easy.

When there are multiple R ²²¹ , the multiple R ²²¹ may be the same or different, and when there is the multiple R ²²² , the multiple R ²²² may be the same or different. All R ²²¹ and R ²²² are preferably the same group for ease of synthesis.

(R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ )
R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aralkyl group, or a substituted is an aromatic hydrocarbon group which may be

Although the alkyl group is not particularly limited, 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, because it tends to improve the solubility of the polymer. Also, 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 and n-hexyl group. , n-octyl group, cyclohexyl group, dodecyl group and the like.

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

Specific examples of the aralkyl group include 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 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- n-heptyl group, 8-phenyl-1-n-octyl group, 4-phenylcyclohexyl group and the like.

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

Specific examples of the aromatic hydrocarbon group include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene. A 6-membered monocyclic or 2-5 condensed monovalent group such as a ring, or a group in which a plurality of these are linked, and the like can be mentioned.

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

The alkyl groups of R ²⁰¹ , R ²⁰² , R ²²¹ and R ²²² , the alkyl groups of R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ , the aralkyl groups and the aromatic hydrocarbon groups may have substituents. Examples of substituents include groups or bridging groups exemplified as preferable groups of the alkyl groups, aralkyl groups and aromatic hydrocarbon groups of R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ . Examples of the cross-linking group include cross-linking groups selected from the cross-linking group T described above.

The alkyl groups represented by R ²⁰¹ , R ²⁰² , R ²²¹ and R ²²² , the alkyl groups represented by R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ , the aralkyl groups and the aromatic hydrocarbon groups are substituents from the viewpoint of voltage reduction. It is most preferred not to have

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

(a, b, c, d, i and j)
In the repeating unit represented by the above formula (54), a and b are each independently an integer of 0-4. It is preferable that a+b is 1 or more, more preferably each of a and b is 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 of the main chain is twisted due to steric hindrance, and the solubility of the polymer in a solvent is excellent. tend to be superior to Therefore, when a + b is 1 or more, when another organic layer (for example, a light-emitting layer) is formed on this coating film by a wet film-forming method, a composition for forming another organic layer containing an organic solvent is used. elution of the polymer is suppressed.

In the repeating unit represented by the above formula (54), c is an integer of 0-3 and d is an integer of 0-4. Each of c and d is preferably 2 or less, more preferably c and d are equal, and it is particularly preferable that 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 ²⁰¹ and R ²⁰² are most preferably bonded at symmetrical positions.

Here, the binding of R ²⁰¹ and R ²⁰² at symmetrical positions means that the binding positions of R ²⁰¹ and R ²⁰² with respect to the fluorene ring, carbazole ring or 9,10-dihydrophenanthrene derivative structure in formula (54) is symmetrical. At this time, 180° rotation around the main chain is regarded as the same structure.

When present, R ²²¹ and R ²²² are each independently preferably present at the 1-, 3-, 6-, or 8-position relative to the carbon atom of the benzene ring to which X is bonded. Due to the presence of R ²²¹ and / or R ²²² at this position, the condensed ring to which R ²²¹ and / or R ²²² is bonded and the adjacent benzene ring on the main chain are twisted due to steric hindrance, resulting in a polymer is excellent in solubility in a solvent, and a coating film formed by a wet film-forming method and then heat-treated tends to be excellent in solubility in a solvent, which is preferable.

When a and b are 0, a twisted structure is preferred because it increases the energy level of the molecule. Therefore, i+j is preferably 1 or more, i and j are each preferably 2 or less, and both i and j are more preferably 1.

(X)
X in the above formula (54) is preferably -C(R ²⁰⁷ )(R ²⁰⁸ )- or -N(R ²⁰⁹ )- because of its high stability during charge transport, and -C(R ²⁰⁷ )(R ²⁰⁸ )— is more preferred.

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

In the formula above, R ²⁰¹ and R ²⁰² are the same, and R ²⁰¹ and R ²⁰² are bonded at symmetrical positions.

<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 structure is preferable.

(In formula (55),
Ar ⁵¹ is the same as Ar ⁵¹ in the formula (54),
R ³⁰³ and R ³⁰⁶ are each independently an optionally substituted alkyl group,
R ³⁰⁴ and R ³⁰⁵ are each independently an optionally substituted alkyl group,
an optionally substituted alkoxy group or an optionally substituted aralkyl group,
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; )

( ^R303 , ^R306 )
R ³⁰³ and R ³⁰⁶ in the repeating unit represented by formula (55) are each independently an optionally substituted alkyl group.

Examples of the alkyl group include the same as those for R ²⁰¹ and R ²⁰² in the formula (54), and the same substituents and preferred structures as those for R ²⁰¹ and R ²⁰² may be mentioned.

When there are a plurality of R ³⁰³ , the plurality of R ³⁰³ may be the same or different, and when there is a plurality of R ³⁰⁶ , the plurality of R ³⁰⁶ may be the same or different.

( ^R304 , ^R305 )
R ³⁰⁴ and R ³⁰⁵ in the repeating unit represented by the formula (55) are each independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or a substituted It is an aralkyl group which may have a group. An optionally substituted alkyl group is preferred.
R ³⁰⁴ and R ³⁰⁴ are preferably the same.

The alkyl group is a linear, branched or cyclic alkyl group. Although the number of carbon atoms in the alkyl group is not particularly limited, it is preferably 1 or more, preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less, because 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 and n-hexyl. group, n-octyl group, cyclohexyl group, dodecyl group and the like.

The alkoxy group is not particularly limited, and the alkyl group represented by R ¹⁰ of the alkoxy group (-OR ¹⁰ ) may have any structure of linear, branched or cyclic, 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, cyclohexyloxy group and the like.

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

Specific examples of the aralkyl group include 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 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 -n-heptyl group, 8-phenyl-1-n-octyl group, 4-phenylcyclohexyl group and the like.

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 R ²⁰⁷ to R ²⁰⁹ and R ²¹¹ to R ²¹⁴ Examples of the cross-linking group include cross-linking groups selected from the cross-linking group group T described above.

The alkyl group, alkoxy group and aralkyl group of R ³⁰⁴ and R ³⁰⁵ most preferably have no substituent from the viewpoint of voltage reduction.

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

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

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

m represents 1 or 2, and the organic electroluminescent device manufactured using the composition of the present invention can be driven at a low voltage, and the hole injection ability, transport ability, and durability tend to be improved. is preferably

(p and q)
p represents 0 or 1; q represents 0 or 1; When l is 2 or more, multiple p may be the same or different, and when n is 2 or more, multiple q may be the same or different. When l=n=1, p and q cannot be 0 at the same time. When p and q are not 0 at the same time, the solubility of the polymer is increased, and precipitation from the composition of the present invention containing the polymer tends to be suppressed. In addition, for the same reason as in a and b above, when p+q is 1 or more, the aromatic ring of the main chain is twisted due to steric hindrance, and the solubility of the polymer in a solvent is excellent. Heat-treated coatings tend to be excellent in solvent insolubility. Therefore, when p + q is 1 or more, when forming another organic layer (for example, a light-emitting layer) on this coating film by a wet film-forming method, a composition for forming another organic layer containing an organic solvent elution of the polymer is suppressed.

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

(In formula (56),
Ar ⁵¹ is the same as Ar ⁵¹ in the formula (54),
Ar ⁴¹ is an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted divalent aromatic heterocyclic group, or the aforementioned divalent aromatic hydrocarbon group and at least one group selected from the group consisting of the divalent aromatic heterocyclic groups is a divalent group in which a plurality of groups are linked directly or via a linking group,
R ⁴⁴¹ and R ⁴⁴² are each independently an optionally substituted alkyl group,
t is 1 or 2;
u is 0 or 1,
r and s are each independently an integer of 0-4. )

( ^R441 , ^R442 )
R ⁴⁴¹ and R ⁴⁴² in the repeating unit represented by formula (56) are each independently an optionally substituted 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, the number of carbon atoms is preferably 1 or more, preferably 10 or less, more preferably 8 or less, and 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 formula (56) above, 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 0-4. When t is 2 or more, multiple r may be the same or different, and when u is 2 or more, multiple s may be the same or different. r+s is preferably 1 or more, and r and s are each preferably 2 or less. When r+s is 1 or more, the drive life of the organic electroluminescence device is considered to be longer for the same reason as a and b in the formula (54).

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

( ^Ar41 )
Ar ⁴¹ is an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted divalent aromatic heterocyclic group, or the aforementioned divalent aromatic hydrocarbon group and a divalent group in which at least one group selected from the group consisting of the above divalent aromatic heterocyclic groups is linked directly or via a linking group.

The aromatic hydrocarbon group and aromatic hydrocarbon group for Ar ⁴¹ include the same groups as for 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 substituent group Z, and the substituent which may be further included in the above substituent group Z is preferably the same as

(In formula (57),
Ar ⁵¹ is the same as Ar ⁵¹ in the formula (54),
R ⁵¹⁷ to R ⁵¹⁹ each independently represent an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or a substituent represents an aromatic hydrocarbon group which may have or an aromatic heterocyclic group which may have a substituent,
f, g, and h each independently represent an integer of 0 to 4,
e represents an integer of 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 these groups may have The group is preferably a group or a cross-linking group selected from the same groups as in the substituent group Z, and the cross-linking group is preferably a cross-linking group selected from the cross-linking group T.

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

The alkoxy groups in R ⁵¹⁷ to R ⁵¹⁹ are preferably the alkoxy groups listed in the above substituent group Z, and the substituents which may be further included are preferably groups selected from the above substituent group Z.

(f, g, h)
f, g, and h each independently represent an integer of 0-4.
When e is 2 or more, multiple g's may be the same or different.
f+g+h is preferably 1 or more.
f + h is preferably 1 or more,
f + h is 1 or more, and f, g and h are more preferably 2 or less,
It is more preferable that 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 at symmetrical positions.
In addition, R ⁵¹⁷ and R ⁵¹⁹ are preferably the same,

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

Here, the binding positions of R ⁵¹⁷ and R ⁵¹⁹ that are symmetrical to each other refer to the following binding positions. However, for notation, 180° rotation about the main chain is regarded as the same structure.

Further, 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 formula (58), g=0 or 2 is preferred. When g=2, the binding positions are the 2nd and 5th positions. When g = 0, i.e., when there is no steric hindrance by R ⁵¹⁸ , and when g = 2 and the binding positions are 2-position and 5-position, i.e., when R ⁵¹⁸ with two steric hindrances binds to the diagonal of the benzene ring In the case of positions, R ⁵¹⁷ and R ⁵¹⁹ can be bonded at symmetrical positions.

Further, 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 formula (59), g=0 or 2 is preferred. When g=2, the binding positions are the 2nd and 5th positions. When g = 0, i.e., when there is no steric hindrance by R ⁵¹⁸ , ^and when g = 2 and the binding positions are 2-position and 5-position, i. In the case of angular positions, R ⁵¹⁷ and R ⁵¹⁹ can be combined 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 thereof include the following structures.

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

( ⁿ⁶⁰ )
ⁿ⁶⁰ represents an integer of 1-5, preferably an integer of 1-4, more preferably an integer of 1-3.

(terminal group)
As used herein, the terminal group refers to the structure of the terminal portion of the polymer compound formed by the end capping agent used at the end of polymerization of the polymer compound. In the composition of the present invention, the terminal group of the polymer compound containing the repeating unit represented by formula (1) is preferably a hydrocarbon group. From the viewpoint of charge transportability, the hydrocarbon group is preferably a hydrocarbon group having 1 to 60 carbon atoms, more preferably a hydrocarbon group having 1 to 40 carbon atoms, and a hydrocarbon group having 1 to 30 carbon atoms. is more preferred.

Examples of the hydrocarbon group include
carbon, 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 A linear, branched or cyclic alkyl group whose number is usually 1 or more, preferably 4 or more, usually 24 or less, preferably 12 or less;
A linear, branched, or cyclic alkenyl group having usually 2 or more and 24 or less, preferably 12 or less carbon atoms, such as a vinyl group;
A linear or branched alkynyl group having usually 2 or more and 24 or less, preferably 12 or less carbon atoms, such as an ethynyl group;
an aromatic hydrocarbon group having usually 6 or more and 36 or less carbon atoms, preferably 24 or less, such as a phenyl group or a naphthyl group;
The cross-linking group which is a hydrocarbon group in the cross-linking group T; preferably the cross-linking groups represented by the above formulas (X1) to (X4);

These hydrocarbon groups may further have a substituent, and the substituent that may further have is preferably an alkyl group or an aromatic hydrocarbon group. Further, when there are a plurality of substituents which may be possessed, they may be combined with each other to form a ring. When these hydrocarbon groups are groups other than cross-linking groups, the substituent may further have a cross-linking group selected from the above-described cross-linking group T.

From the viewpoint of charge transportability and durability, the terminal group is preferably an alkyl group, an aromatic hydrocarbon group, or a cross-linking group that is a hydrocarbon group in the cross-linking group group T, more preferably an aromatic When it is a hydrocarbon group and the terminal group is not a cross-linking group, it is also preferable to further have a cross-linking group selected from the above-mentioned cross-linking group group T.

[Molecular Weight of Polymer Compound]
The molecular weights of the polymer compounds contained in the composition of the present invention are described below.

The weight-average molecular weight (Mw) of the fluorine-containing arylamine polymer compound is usually 1,000,000 or less, preferably 500,000 or less, more preferably 100,000 or less, and still more preferably 70,000 or less. Particularly preferably, it is 50,000 or less. Moreover, the weight average molecular weight is usually 5,000 or more, preferably 10,000 or more, more preferably 12,000 or more, and particularly preferably 15,000 or more.

When the weight-average molecular weight of the fluorine-containing arylamine polymer compound is equal to or less than the above upper limit, solubility in a solvent is obtained, and film-forming properties tend to be excellent. Further, when the weight average molecular weight of the polymer compound is at least the above lower limit, the decrease in the glass transition temperature, melting point and vaporization temperature of the polymer compound may be suppressed and the heat resistance may be improved. In addition, in some cases, the coating film after the cross-linking reaction is sufficiently insoluble in organic solvents.

The number average molecular weight (Mn) of the fluorine-containing arylamine polymer compound is generally 750,000 or less, preferably 250,000 or less, more preferably 100,000 or less, and particularly preferably 50,000 or less. be. Moreover, the number average molecular weight is usually 2,000 or more, preferably 4,000 or more, more preferably 6,000 or more, and still more preferably 8,000 or more.

Further, the polydispersity (Mw/Mn) of the fluorine-containing arylamine polymer compound is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. Note that the lower limit value is ideally 1 because the smaller the value of the degree of dispersion, the better. When the degree of dispersion of the polymer compound is equal to or less than the above upper limit, purification is easy, and solubility in a solvent and charge transportability are good.

　Usually, the weight average molecular weight and number average molecular weight of a polymer compound are determined by SEC (size exclusion chromatography) measurement. In SEC measurement, the higher the molecular weight, the shorter the elution time, and the lower the molecular weight, the longer the elution time. By conversion, the weight average molecular weight and number average molecular weight are calculated.

(Content of repeating unit represented by formula (1))
In the polymer compound, the content of the repeating unit represented by formula (1) is not particularly limited, but the repeating unit represented by formula (1) is usually 10 mol per 100 mol% of all repeating units in the polymer compound. % or more, preferably 30 mol % or more, more preferably 40 mol % or more, even more preferably 50 mol % or more.

In the polymer compound, the repeating unit may be composed only of repeating units represented by formula (1). It may have a repeating unit other than the repeating unit shown. In that case, the content of the repeating unit represented by formula (1) in the polymer is usually 99 mol % or less, preferably 95 mol % or less.

[Concrete example]
Specific examples of the polymer compound are shown below, but the polymer compound is not limited to these. The numbers in the chemical formulas represent the molar ratio of repeating units.

These polymer compounds may be random copolymers, alternating copolymers, block copolymers, graft copolymers, or the like, and the sequence of the monomers is not limited.

<Method for producing polymer>
The method for producing the polymer compound contained in the composition of the present invention is not particularly limited and is arbitrary. Examples thereof include a polymerization method by Suzuki reaction, a polymerization method by Grignard reaction, a polymerization method by Yamamoto reaction, a polymerization method by Ullmann reaction, a polymerization method by Buchwald-Hartwig reaction, and the like. Moreover, it can be manufactured by the manufacturing method similar to the manufacturing method of the polymer as described in WO2019/177175, WO2020/171190, and WO2021/125011.

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

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

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

(In the above reaction scheme, 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 polymerization method described above, 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. It can also be carried out in the presence of a transition metal catalyst such as copper or a palladium complex.

<Content of fluorine-containing arylamine polymer compound of the present invention>
From the viewpoint of reducing the injection barrier in the charge transport layer in the composition ratio of the solid components of the composition of the present invention, the content of the fluorine-containing arylamine polymer compound of the present invention is preferably 10% by mass or more, and preferably 25% by mass. The above is more preferable, and 30% by mass or more is even more preferable. On the other hand, from the viewpoint of maintaining the charge transport property in the charge transport layer, the content of the fluorine-containing arylamine polymer compound of the present invention in the composition of the present invention is 99% in terms of the composition ratio of the solid components of the composition. It is preferably 90% by mass or less, more preferably 80% by mass or less.

[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 in the hole injection layer or the hole transport layer, a hole injection layer or a hole The charge transport material contained in the transport layer preferably contains cation radical sites. An electron-accepting compound is used when forming a hole-injecting layer or a hole-transporting layer in order to convert the charge-transporting material into cation radicals. As the base skeleton of the electron-accepting compound, an ionic compound composed of a tetraarylborate ion, which is an anion having an ion valence of 1, and a counter cation, which will be described later, is preferable because of its high stability.

(Cation radicalization of charge transport material)
Cation radicalization of the charge transport material is carried out as follows.
When the fluorine-containing arylamine polymer compound of the present invention is used as the charge-transporting material, a hole-injecting layer or a hole-transporting layer can be formed by using a tetraarylborate having a diaryliodonium as a counter cation as an electron-accepting compound. Upon formation, the counter cation can change from a diaryliodonium to an arylamine cation, as in the formula below.

(For example, Ar, Ar ^1′ to Ar ^4′ each independently represent an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a substituent It is a monovalent group in which a plurality of structures selected from an optionally substituted aromatic hydrocarbon ring group and an optionally substituted aromatic heterocyclic group are linked.)

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

In the present invention, a compound composed of tetraarylborate ions, which are cations and anions of the charge-transporting material, is referred to as a charge-transporting ionic compound. Details will be described later.

As will be described later, the hole injection layer and/or the hole transport layer of the organic electroluminescent device of the present invention is preferably obtained by wet film formation of the composition of the present invention. It is preferably a composition obtained through a step of dissolving or dispersing an electron-accepting compound having a tetraarylborate ion structure and a charge-transporting material described later 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. preferably included.

(Crosslinking reaction product)
The composition of the present invention contains a polymer compound having a cross-linking group and an electron-accepting compound having a cross-linking group. Therefore, the organic layer formed by the wet film-forming method using the composition of the present invention contains a cross-linked reaction product of a polymer compound having a cross-linking group and an electron-accepting compound having a cross-linking group. Furthermore, as will be described later, the electron-accepting compound of the present invention is preferably an ionic compound consisting of a tetraarylborate ion and a counter cation, and the tetraarylborate ion preferably has a cross-linking group. Therefore, the organic layer can contain a cross-linking reactant containing the following cross-linked structure.
・Crosslinked structure between polymer compound and electron-accepting compound ・Crosslinked structure between crosslinkable groups of polymer compound ・Crosslinked structure between electron-accepting compounds ・Crosslinked structure between electron-accepting compound and tetraarylborate ion ・Tetraarylborate Compounds in which acid ions are crosslinked ・Crosslinked structure of polymer compounds and tetraarylborate ions

The tetraarylborate ion is an anion structural site that constitutes the electron-accepting compound. In the crosslinked structure, the tetraarylborate ion is a tetraarylborate ion ionically bonded to the cation radical of the polymer compound. Details will be described later.

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

The two cross-linking groups that undergo a cross-linking reaction may be the same cross-linking group or different cross-linking groups as long as they are cross-linkable.

[Electron-accepting compound]
The electron-accepting compound, which is an ionic compound composed of a tetraarylborate ion and a counter cation, is an electron-accepting ionic compound composed of a counter anion, which is a non-coordinating anion represented by the following formula (81), and a counter cation, , has a bridging group. The non-coordinating anion represented by formula (81) below preferably has formula (83), which will be described later, as a tetraarylborate ion. Incidentally, the electron-accepting compound used in the present invention may be called an electron-accepting ion compound.

The electron-accepting compound represented by formula (81) has a cross-linking group, and the number of cross-linking groups is preferably two or more. The bridging group is preferably provided in the anion portion of the electron-accepting compound represented by the formula (81), that is, the compound represented by the below-described formula (82), which is a tetraarylborate ion.

[Tetraarylborate ion]
As the backbone of the above-described electron-accepting compound, the boron atom is substituted with four aromatic hydrocarbon rings optionally having substituents or aromatic heterocycles optionally having substituents , an ionic compound composed of a tetraarylborate ion, which is an anion with an ionic valence of 1, and a counter cation is preferable because of its high stability.

A tetraarylborate ion is an anion of the above formula (81) 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).
Ph ¹ to Ph ⁴ are the same as Ph ¹ to Ph ⁴ in formula (81), 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. As the aromatic hydrocarbon ring structure, a single ring, 2 to 6 condensed rings, and a structure in which 2 to 8 of these are linked are preferable. Specific examples of aromatic hydrocarbon groups include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene Single monovalent groups having a ring, biphenyl structure, terphenyl structure, or quaterphenyl structure, and monovalent groups in which 2 to 8 of these are linked are included.

The aromatic heterocyclic group used for R ⁸¹ to R ⁸⁴ preferably has 3 to 50 carbon atoms. As the aromatic heterocyclic ring structure, a single ring, 2 to 6 condensed rings, and a structure in which 2 to 8 of these are linked are preferable. Specific examples of aromatic heterocyclic groups include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, 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 A monovalent group is mentioned. Furthermore, the aromatic heterocyclic group referred to herein may contain at least one of these independent structures, and the connecting structure may contain an aromatic hydrocarbon ring structure. When it contains an aromatic hydrocarbon ring structure, it may have a structure in which 2 to 8 of the above aromatic heterocycles and aromatic hydrocarbon rings are combined. Here, as the aromatic hydrocarbon ring, a single structure of the aromatic hydrocarbon ring used for R ⁸¹ to R ⁸⁴ can be used.

Among them, since they are excellent in stability and heat resistance, monovalent groups such as benzene, naphthalene, fluorene, pyridine or carbazole rings, or biphenyl groups in which 2 to 5 of these groups are linked. groups are more preferred. A monovalent group of a benzene ring or a group in which 2 to 5 benzene rings are linked is particularly preferred, and specific examples thereof include a phenyl group, a biphenyl group and a terphenyl group.

An aromatic hydrocarbon group contained in a monovalent group in which a plurality of structures selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked and 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, it is regarded as a structure in which two, three, or four phenyl groups are linked, respectively.

As the substituent that R ⁸¹ to R ⁸⁴ may have, a group selected from the substituent group Z or the bridging group group T is preferable.

R ⁸¹ to R ⁸⁴ are each independently 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. Moreover, it preferably contains 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 is substituted with a fluorine atom, more preferably a perfluoroalkyl group. A linear or branched perfluoroalkyl group having 1 to 5 carbon atoms is more preferable, a linear or branched perfluoroalkyl group having 1 to 3 carbon atoms is particularly preferable, and a perfluoromethyl group is most preferable. The reason for this is that the charge injection layer containing the cross-linking reaction product of the electron-accepting compound having a cross-linking group and the coating film laminated thereon are stabilized. The fluorine-substituted alkyl group is preferably attached 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 preferably a group represented by the following formula (84) having four fluorine atoms, and in terms of improving the stability of the anion, it is preferable that at least two of them are groups represented by the same formula (84). More preferably, at least three of them are the same group represented by the following formula (84) from the viewpoint of further improving the stability of the anion.

(In formula (84), * represents a bond with boron B in formula (82), _F4 represents that four fluorine atoms are substituted,
^R85 represents an optionally substituted aromatic hydrocarbon group or a bridging group. )

The aromatic hydrocarbon group that can be used for R ⁸⁵ preferably has 3 to 40 carbon atoms. As the aromatic hydrocarbon ring structure, a single ring, 2 to 6 condensed rings, and a structure in which 2 to 5 of these are linked are preferable. 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 , or a single monovalent group having a quaterphenyl structure, and a monovalent group in which 2 to 6 of these are linked. The cross-linking group which the aromatic hydrocarbon group may have is preferably a cross-linking group selected from the above-described cross-linking group T.

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

<Ionic compound containing tetraarylborate ion>
A tetraarylborate ion is used as an electron-accepting ion compound containing a tetraarylborate ion.

(counter 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.

The structure represented by the following formula (83) is preferable as the iodonium cation, and the more preferable structure is the same.

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

Specific examples of 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, trisubstituted carbocations such as triphenyl carbocation, tri(methylphenyl) carbocation, and tri(dimethylphenyl) carbocation are preferred as carbocations.

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

Specific examples of phosphonium cations include tetraarylphosphonium cations such as tetraphenylphosphonium cations, tetrakis(methylphenyl)phosphonium cations and tetrakis(dimethylphenyl)phosphonium cations; tetraalkylphosphonium cations such as tetrabutylphosphonium cations and tetrapropylphosphonium cations. etc. are preferred.

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

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

In formula (83), Ar ⁸¹ and Ar ⁸² are each independently an optionally substituted aromatic hydrocarbon group having 6 to 12 carbon atoms.

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 substituent which may be present is a group selected from the above-described substituent group Z, most preferably an alkyl group.

Preferable aromatic hydrocarbon groups include phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthrenyl, triphenylene, and naphthylphenyl groups. preferable.

(molecular weight)
The molecular weight of the electron-accepting compound of the present invention is usually 900 or more, preferably 1000 or more, more preferably 1200 or more, and usually 10000 or less, preferably 5000 or less, more preferably 3000 or less. If the molecular weight is too small, the delocalization of the positive and negative charges is insufficient, which may reduce the electron-accepting ability. If the molecular weight is too large, the charge transport may be hindered.

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

<Composition ratio/content of fluorine-containing arylamine polymer compound and electron-accepting compound in composition>
In the composition of the present invention, the content of the polymer compound of the present invention is 99% by mass or less with respect to the total amount of the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound of the present invention. is preferred, 97% by mass or less is more preferred, and 95% by mass or less is even more preferred. Moreover, it is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. Within these ranges, the film formed using the composition of the present invention is sufficiently crosslinked to be insolubilized, and the film formed using the composition of the present invention can be directly wet-coated to form a film. In addition, when the film formed using the composition of the present invention is used as a charge injection film, the injection barrier in the charge transport layer is reduced, the charge transport property is excellent, and the stability during charge transport is improved. It is believed that the durability of the device containing the film formed using the composition of the present invention is improved.

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

<Solvent>
The composition of the present invention preferably contains the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound of the present invention. Furthermore, it is preferable that a solvent is included. In particular, when the composition of the present invention is used to form a charge transport film by a wet film-forming method, a solvent is used to combine the fluorine-containing arylamine polymer compound of the present invention with the electron-accepting compound of the present invention. It is preferably in a dissolved state.

The type of solvent contained in the composition of the present invention is not particularly limited as long as it can dissolve both the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound of the present invention. . Here, the fluorine-containing arylamine polymer compound of the present invention and the solvent for dissolving the electron-accepting compound of the present invention preferably contain 0.005% by mass or more of the fluorine-containing arylamine polymer compound of the present invention. More preferably 0.5% by mass or more, more preferably 1% by mass or more is a solvent that dissolves. The solvent preferably dissolves the electron-accepting compound in an amount of 0.001% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.2% by mass or more.

Preferred solvents include, for example, aromatic hydrocarbon solvents, ether solvents and ester solvents.

Specifically, aromatic hydrocarbon solvents include toluene, xylene, mesitylene, tetralin, and cyclohexylbenzene.

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

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, benzoic acid; 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 ether solvents and ester solvents described above include amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethyl sulfoxide. Any one of these may be used alone, or two or more thereof may be used in any combination and ratio. Also, one or more of these solvents may be used in combination with one or more of the ether solvents and ester solvents described above. In particular, aromatic hydrocarbon solvents such as benzene, toluene, and xylene have low ability to dissolve electron-accepting compounds and free carriers (cation radicals), so they can be used by mixing with ether solvents and ester solvents. preferable.

When a solvent is used, the solvent concentration relative to the composition of the present invention is preferably 10% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more. The concentration of the solvent in the composition is preferably 99.999% by mass or less, more preferably 99.99% by mass or less, and still more preferably 99.9% by mass or less. When two or more solvents are mixed and used, the total of these solvents should satisfy this range.

When the composition of the present invention is used in an organic electroluminescent element, each layer is required to be a uniform layer because the organic electroluminescent element is formed by laminating a large number of layers composed of organic compounds. . When a layer is formed by a wet film-forming method, if water is present in the solution (composition) for thin film formation, the water will be mixed in the coating film and the uniformity of the film will be impaired. Less is better. In addition, the presence of moisture is not preferable from the viewpoint of deterioration of the element, because organic electroluminescence elements generally use many materials, such as cathodes, that are significantly deteriorated by moisture.

Specifically, the amount of water contained in the composition of the present invention is preferably 1% by mass or less, more preferably 0.1% by mass or less, and more preferably 0.05% by mass or less.

Examples of methods for reducing the amount of water in the composition include sealing with nitrogen gas, using a desiccant, dehydrating the solvent in advance, and using a solvent with low water solubility. Among them, it is preferable to use a solvent with low water solubility from the viewpoint of preventing the solution coating film from whitening due to absorption of moisture in the atmosphere during the coating process.

When used for film formation by a wet film-forming method, the composition of the present invention is a solvent having a low water solubility, specifically, a water solubility at 25° C. of 1% by mass or less, preferably 0.1% by mass. % or less, preferably 10% by mass or more, more preferably 30% by mass or more, particularly preferably 50% by mass or more, based on the total composition.

<Composition for charge transport film>
When the electron-accepting compound having a cross-linking group is the electron-accepting ionic compound, a composition containing the electron-accepting ionic compound and the fluorine-containing arylamine polymer compound of formula (1) (hereinafter referred to as , appropriately referred to as "charge-transporting film composition (A)"), or a cation radical of an arylamine polymer compound containing fluorine having a cross-linking group described later and a counter anion which is a part of the electron-accepting ion compound. is preferably used as a composition containing a charge-transporting ionic compound consisting of Here, for the sake of convenience, the charge transport film composition (A) and the charge transport film composition (B) will be described separately. A charge-transporting property comprising a cation radical of an arylamine polymer compound containing fluorine having a group and a cation radical of the arylamine polymer compound containing fluorine having a crosslinking group described later and a counter anion which is a part of the electron-accepting ion compound. Also included are compositions comprising ionic compounds.

The charge transport film compositions (A) and (B) are compositions (compositions for charge transport materials) that can be widely used as charge transport materials. However, since it 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 will be referred to as the "composition for

<Composition for charge transport film (A)>
The charge-transporting film composition (A) comprises the fluorine-containing arylamine polymer compound having a cross-linking group, the electron-accepting compound having a cross-linking group, and a solvent. The fluorine-containing arylamine polymer compound may be contained singly or in combination of two or more kinds.

<Method for preparing composition (A) for charge transport film>
The charge-transporting film composition (A) is prepared by mixing at least the fluorine-containing arylamine polymer compound of the present invention with the electron-accepting compound having a cross-linking group. At this time, the charge-transporting film composition (A) contains a solvent, and the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound having a cross-linking group are dissolved in the solvent and mixed. is preferred.

The content of the electron-accepting compound having a crosslinkable group of the present invention in the composition (A) for a charge transport film is usually 0.1% by mass or more in terms of the fluorine-containing arylamine polymer compound of the present invention. , preferably 1% by mass or more, and usually 100% by mass or less, preferably 40% by mass or less. If the content of the electron-accepting compound is at least the above lower limit, free carriers (cation radicals of the fluorine-containing arylamine polymer compound of the present invention) can be sufficiently generated, and if it is at most the above upper limit, it is sufficient. It is preferable because the charge transport ability can be ensured. When two or more electron-accepting compounds are used in combination, the total content of these should be within the above range. The same applies to charge-transporting compounds.

<Composition for charge transport film (B)>
The charge-transporting film composition (B) contains, as described above, a charge-transporting ionic compound comprising a cation radical of the fluorine-containing arylamine polymer compound of the present invention and a counter anion of the electron-accepting ionic compound. It is a composition that

The cation radical of the fluorine-containing arylamine polymer compound of the present invention, which is the cation of the charge-transporting ionic compound, is obtained from the electrically neutral compound shown in the fluorine-containing arylamine polymer compound of the present invention. It is a chemical species with one electron removed.

The cation radical of the fluorine-containing arylamine polymer compound of the present invention is a fluorine-containing arylamine polymer compound having a structure represented by the following formula (110).

[In the above formula (110),
Ar ^1a , Ar ^2a and G ^1a are respectively the same as Ar ¹ , Ar ² and G in the formula (1). ]

Formula (110) is particularly a fluorine-containing arylamine polymer compound having a structure represented by the following formula (110-1). It is preferable because it is

[In the above formula (110-1),
Ar ^1b is an aromatic hydrocarbon group, and the number of carbon atoms in the aromatic hydrocarbon group is preferably 6-30, more preferably 6-24, still more preferably 6-18. Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, a fluorene ring, a tetraphenylene ring, and the like, having usually 6 or more and usually 30 or less, preferably 18 or less, more preferably 14 or less carbon atoms. A bivalent group having a certain aromatic hydrocarbon ring structure, or a bivalent group having a structure in which a plurality of structures selected from these structures are bonded in a chain or branched manner is exemplified. When a plurality of aromatic hydrocarbon rings are linked, a structure in which 2 to 7 rings are linked is usually mentioned, and a structure in which 2 to 5 rings are linked is preferable. When a plurality of aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.
Ar ^2a and G ^1a are the same as Ar ² and G in formula (1) above, respectively. ]

Ar ^1b is preferably an aromatic hydrocarbon group having a substituent, and specific examples thereof, preferred groups, examples of optionally substituted substituents and examples of preferred substituents are selected from the substituent group Z is preferred. Particularly preferred is an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent.

Ar ^1b is preferably a phenylene group, a biphenylene group, or a phenylfluorene group, more preferably a phenylene group or a biphenylene group, from the viewpoints of charge transport and that the partial structure represented by formula (110-1) tends to become a cation radical. and a phenylene group is particularly preferred.

<Charge-transporting ionic compound>
The charge-transporting ionic compound is a compound in which the cation radical of the fluorine-containing arylamine polymer compound of the present invention is ionically bonded to a counter anion that is a part of the electron-accepting ionic compound.

A charge-transporting ionic compound can be obtained by mixing an arylamine polymer compound containing fluorine and an electron-accepting ionic compound, and is easily dissolved in various solvents. Specifically, it can be obtained by the method described in <Method for preparing composition (B) for charge transport film> described below.

The weight average molecular weight (Mw) of the charge-transporting ionic compound is usually 1,000,000 or less, preferably 500,000 or less, more preferably 100,000 or less, still more preferably 70,000 or less, particularly preferably 50,000 or less. 000 or less. Moreover, the weight average molecular weight is usually 5,000 or more, preferably 10,000 or more, more preferably 12,000 or more, and particularly preferably 15,000 or more.

<Method for preparing composition (B) for charge transport film>
The charge-transporting ionic compound (B) is preferably prepared by dissolving and mixing the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting ionic compound in a solvent. In this solution, the fluorine-containing arylamine polymer compound of the present invention is oxidized by the electron-accepting ion compound to form a cation radical, and the counter anion of the electron-accepting ion compound and the fluorine-containing arylamine of the present invention are converted into cation radicals. A charge-transporting ionic compound, which is an ionic compound with the cation radical of the polymer compound, is produced.

This is for the following reasons. That is, at this time, by mixing the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting ion compound in a solution, the easily oxidizable site of the fluorine-containing arylamine polymer compound of the present invention The probability that the electron-accepting ion compound exists in the vicinity of the arylamine nitrogen atom is increased. Then, the electron-accepting ionic compound oxidizes the arylamine nitrogen atom of the fluorine-containing polymer compound of the present invention to form a cation radical, forming a counter anion of the electron-accepting ion compound and the fluorine-containing polymer of the present invention. An ionic compound is likely to form with the cation radical of the compound. At this time, it is preferable to heat the solution from the viewpoint of promoting the reaction.

It is also preferable to prepare by heating a mixture of the electron-accepting ionic compound and the fluorine-containing polymer compound of the present invention. This mixture is preferably a film formed by coating and drying a solution obtained by dissolving a mixture of an electron-accepting ionic compound and the fluorine-containing polymer compound of the present invention in a solvent.

This is for the following reasons. That is, by heating the mixture, the electron-accepting ion compound and the fluorine-containing polymer compound of the present invention mutually diffuse in the mixture, and at the easily oxidizable sites of the fluorine-containing polymer compound of the present invention. The probability that an electron-accepting compound exists in the vicinity of the nitrogen atom of a certain arylamine increases. Then, an ionic compound of the counter anion of the electron-accepting ionic compound and the cation radical of the fluorine-containing polymer compound of the present invention is likely to be generated. The heating temperature at this time is preferably a temperature at which the cross-linking groups of the composition do not undergo a cross-linking reaction. It is formed.

The charge-transporting 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 one type alone. This is because the ionization potential of the charge-transporting ionic compound has little variation and the hole-transporting property is excellent.

A composition containing one type of charge-transporting ionic compound alone or two types is defined as a composition prepared by using only two or three types in total of the electron-accepting ionic compound and the fluorine-containing polymer compound of the present invention. The composition is prepared using at least one electron-accepting ion compound and at least one fluorine-containing polymer compound of the present invention.

The charge-transporting film formed from the charge-transporting-film composition (B) exhibits a high hole injection/transport capability due to positive charge transfer from the charge-transporting ionic compound to a nearby neutral charge-transporting compound. Demonstrate. For this reason, the mass ratio of the charge-transporting ionic compound and the neutral fluorine-containing polymer compound of the present invention is preferably about 1:100 to 100:1, more preferably about 1:20 to 20:1. is more preferable.

<Relationship between composition for charge transport film (A) and (B)>
The charge transport film formed from the charge transport film composition (A) has excellent heat resistance and high hole injection/transport capability. The reason why such excellent properties are obtained will be explained below.

The charge-transporting film composition (A) contains the electron-accepting compound and the charge-transporting compound described above. The cation in the electron-accepting ionic compound has a hypervalent central atom and its positive charge is widely delocalized, so it has a high electron-accepting property. 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 composed of the cation radical of the charge-transporting compound and the counter anion is generated. Since the cation radicals of the charge-transporting compound serve as charge carriers, the electrical conductivity of the charge-transporting film can be increased. That is, it is considered that when the charge transport film composition (A) is prepared, a charge transporting ionic compound at least partially composed of the cation radical of the charge transporting compound and the counter anion of the electron accepting ion compound is produced.

For example, when electron transfer occurs from the charge-transporting compound represented by the following formula (7) to the electron-accepting compound represented by the formula (6), the charge-transporting compound represented by the formula (9) A charge-transporting ionic compound consisting of a cation radical and a counter-anion is produced.

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

The composition after heating can be filtered using a membrane filter, depth filter, etc. to remove coarse particles before use. Considering that the composition is applied by ejecting from the nozzle of an inkjet head, the pore size 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.

[Method of forming a film using the 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 used for wet film formation.

The wet film formation method is a method in which a composition containing a solvent is applied onto a substrate and the solvent is removed by drying to form a film. The coating method is not particularly limited, but for example, spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet, screen printing, A gravure printing method, a flexographic printing method, and the like can be mentioned.

Heat drying is usually used to remove the solvent by drying. Examples of heating means used in the heating step include clean ovens, hot plates, and infrared heating. As infrared heating, a halogen heater, a ceramic-coated halogen heater, a ceramic heater, or the like can be used.

Since infrared heating gives heat energy directly to the substrate or film, drying can be done in a short time compared to heating using an oven or hot plate. Therefore, the influence of gases (moisture and oxygen) in the heating atmosphere and the influence of fine dust can be minimized, and productivity is improved, which is preferable.

The heating temperature is usually 80°C or higher, preferably 100°C or higher, more preferably 150°C or higher. Also, the heating temperature is usually 300° C. or lower, preferably 280° C. or lower, 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.
It is also preferable to perform vacuum drying before heat drying.

The film thickness of the organic layer formed by forming 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. Also, the film thickness is usually 1000 nm or less, preferably 500 nm or less, more preferably 300 nm or less.

[Organic electroluminescent device]
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 electroluminescence device.

The organic electroluminescent device is, for example, an organic electroluminescent device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, and the organic layer is formed using the composition of the present invention. It is preferably formed by a wet film-forming method. The organic layer is preferably an organic layer between the anode and the light-emitting layer. A device using "quantum dots", which are inorganic light-emitting substances, in the light-emitting layer of the organic electroluminescent device is also called a quantum dot light-emitting device.

Further, the organic layer has a repeating unit represented by the formula (1), has a fluorene which may have a substituent in at least one of the main chain and the side chain, and has a cross-linking group. It preferably contains a crosslinked reaction product of a polymer compound and an electron-accepting compound having a crosslinkable group represented by the above formula (81).

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

[substrate]
The substrate 1 serves as a support for the organic electroluminescence element, and is usually made of a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like. Among these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate and polysulfone are preferred. The substrate is preferably made of a material having a high gas barrier property because deterioration of the organic electroluminescence element due to outside air is unlikely to occur. Therefore, especially when using a material having 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 the function of injecting holes into the layer on the light-emitting layer 5 side.

Anode 2 is typically made of metals such as aluminum, gold, silver, nickel, palladium, platinum; metal oxides such as indium and/or tin oxide; metal halides such as copper iodide; carbon black and poly(3 -methylthiophene), polypyrrole, and polyaniline.

The formation of the anode 2 is usually carried out by dry methods such as sputtering and vacuum deposition. In addition, when the anode is formed 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., an appropriate binder resin solution may be used. It can also be formed by dispersing and coating on a substrate. In the case of a conductive polymer, a thin film can be formed directly on a substrate by electrolytic polymerization, or an anode can be formed by coating a conductive polymer on a substrate (Appl. Phys. Lett., 60 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 according to the required transparency and material. When particularly high transparency is required, the thickness is preferably such that the visible light transmittance is 60% or more, and more preferably the thickness is 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, when transparency is not required, the thickness of the anode 2 may be arbitrarily set according to the required strength, etc. In this case, the thickness of the anode 2 may be the same as that of the substrate.

When another layer is formed on the surface of the anode 2, the impurity on the anode 2 is removed and its ionization potential is changed by treating with ultraviolet rays/ozone, oxygen plasma, argon plasma, etc. before the film formation. is preferably adjusted to improve the hole injection property.

[Hole injection layer]
A layer that functions to transport 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 that function to transport holes from the anode 2 side to the light emitting layer 5 side, the layer closer to the anode side may be called the hole injection layer 3 . The hole injection layer 3 is preferably formed in order to enhance 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 crosslinked reaction product of the fluorine-containing arylamine polymer 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 deposition method and a wet film formation method. In the case of layer formation by a wet film-forming method, the composition of the present invention is prepared, applied onto the anode 2 by a wet film-forming method such as a spin coating method or a dip coating method, and dried to form a hole injection layer 3. form.

It is particularly preferable to use a composition containing the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound of the present invention, and to use the fluorine-containing arylamine of the present invention. It is to use a film formed using a composition containing a polymer compound and the electron-accepting compound of the present invention.
The film thickness of the hole injection layer 3 thus formed is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

A method for forming the hole injection layer may be a vacuum deposition method or a wet film formation method. From the viewpoint of excellent film-forming properties, it is preferable to form the film by a wet film-forming method.
Examples of the solvent include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, amide-based solvents, and the like.

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

Examples of ester-based solvents 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, and methylnaphthalene. be done.

Examples of amide-based solvents 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 carried out by preparing a composition for forming a 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). It is carried out by coating and forming a film on the surface and drying it.

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

[Hole transport layer]
The hole transport layer 4 is a layer that functions to transport holes from the anode 2 side to the light emitting layer 5 side. The hole transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, but it is preferable to form this layer in terms of enhancing 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, when 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 is usually 300 nm or less, preferably 100 nm or less.

A material that forms the hole transport layer 4 is preferably a material that has a high hole transport property and can efficiently transport the injected holes. Furthermore, it is preferable that the injection barrier from the hole injection layer to the hole transport layer is low. Therefore, it is preferable that the ionization potential is appropriate, the transparency to visible light is high, the hole mobility is large, the stability is excellent, and impurities that become traps are less likely to occur during manufacture and use. In many cases, since the hole transport layer 4 is in contact with the light emitting layer 5, it does not quench the light emitted from the light emitting layer 5 or form an exciplex with the light emitting layer 5 to reduce the efficiency. is preferred.

As the material for such a hole transport layer 4, any material can be used as long as it is a material conventionally used as a constituent material for a hole transport layer. Examples of compounds include those exemplified. Also, 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, condensed polycyclic aromatic group derivatives, metal complexes, and the like.

Also, for example, polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ether sulfone derivatives containing tetraphenylbenzidine, polyarylene vinylene derivatives, polysiloxane derivatives, polythiophenes. derivatives, poly(p-phenylene vinylene) derivatives and the like. These may be alternating copolymers, random polymers, block polymers or graft copolymers. Also, a polymer having a branched main chain and three or more terminal portions, or a so-called dendrimer may be used.

Among them, polyarylamine derivatives and polyarylene derivatives are preferred.
As the polyarylamine derivative, a polymer containing a repeating unit represented by the following formula (I) is preferred. In particular, a polymer composed of repeating units represented by the following formula (I) is preferable, 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 optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group represents.)

Examples of polyarylene derivatives include polymer compounds having an arylene group such as an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group as a repeating unit. be done.

As the polyarylene derivative, a polymer compound having a repeating unit represented by 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, 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, a plurality of groups contained in one molecule may be the same or different, and adjacent Ra ^or ^Rb 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 formula (II-1) above. x13 and x14 are each independently represents an integer of 0 to 3. When x13 or x14 is 2 or more, a plurality of 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 together, and L represents an atom or a group of atoms constituting a 5- or 6-membered ring.)

Specific examples of L include an oxygen atom, an optionally substituted boron atom, an optionally substituted nitrogen atom, an optionally substituted silicon atom, and an optionally substituted an optionally substituted phosphorus atom, an optionally substituted sulfur atom, an optionally substituted carbon atom, or a group formed by combining these atoms.

Further, the polyarylene derivative has 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 optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group; x15 and x16 each independently represent 0 or 1.)

Specific examples of the above formulas (III-1) to (III-3) and specific examples of the polyarylene derivative include those described in JP-A-2008-98619.

When the hole transport layer 4 is formed 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, and after wet film formation, heat drying is performed. .

The hole-transporting layer-forming composition contains a solvent in addition to the hole-transporting compound described above. The solvent to be used is the same as that used for the composition for forming the hole injection layer. Further, the film formation conditions, heat drying conditions, etc. are the same as in the case of forming the hole injection layer 3 .

In the case of forming the hole transport layer by vacuum evaporation, the film forming conditions and the like are the same as in the case of forming the hole injection layer 3 described above.

The hole-transporting layer 4 may contain various light-emitting materials, electron-transporting compounds, binder resins, coatability improvers, etc., in addition to the above hole-transporting compounds.

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

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

The crosslinkable compound may be a monomer, oligomer, or polymer. The crosslinkable compound may have only one type, or may have two or more types in any combination and ratio.

A hole-transporting compound having a crosslinkable group is preferably used as the crosslinkable compound. Examples of the hole-transporting compound include those exemplified above, and examples of the cross-linking compound include those in which a cross-linking group is bonded to the main chain or side chain of these hole-transporting compounds. be done. In particular, the crosslinkable group is preferably bonded to the main chain via a linking group such as an alkylene group. In particular, the hole-transporting compound is preferably a polymer containing a repeating unit having a crosslinkable group. is preferably a polymer compound having repeating units linked directly or via a linking group.

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

The film thickness of the hole transport layer 4 thus formed 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 functions to emit light by being excited by recombination of holes injected from the anode 2 and electrons injected from the cathode 7 when an electric field is applied between a pair of electrodes. . The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 7, and the light-emitting layer is formed between the hole-injection layer and the cathode, if there is a hole-injection layer on the anode, and the anode If there is a hole-transport layer on top, it is formed between the hole-transport layer and the cathode.
As described above, the organic electroluminescent element in the present invention preferably contains a light-emitting layer-forming material suitable for the light-emitting layer.

The film 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 film is preferable because defects are less likely to occur in the film, and a thinner film is preferable because a low driving voltage can be easily achieved. . Therefore, 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, 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 material for forming light-emitting layer]
The light-emitting layer in the present invention contains a light-emitting material and a charge transport material. The luminescent material may be a phosphorescent luminescent material or a fluorescent luminescent material. Charge Transport Film Preferably, the red-emitting material and the green-emitting material are phosphorescent materials, and the blue-emitting material is a fluorescent material.

<Phosphorescent material>
A phosphorescent material is a material that emits light from an excited triplet state. For example, metal complex compounds containing Ir, Pt, Eu, etc. are typical examples, and materials containing metal complexes are preferable as the structure of the material.

Among metal complexes, the long-period periodic table (unless otherwise specified, the long-period periodic table ) include Werner-type complexes or organometallic complex compounds containing a metal selected from Groups 7 to 11 as a central metal. Examples of such phosphorescent materials include those described in International Publication No. 2014/024889, International Publication No. 2015-087961, International Publication No. 2016/194784, and JP-A-2014-074000. 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 optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic ring structure.
Ring A2 represents an aromatic heterocyclic structure which may have a substituent.
R ¹⁰¹ and R ¹⁰² each independently represent 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 multiple R ¹⁰¹ and R ¹⁰² are present, they may be the same or different.

Ar ²⁰¹ and Ar ²⁰³ each independently represent an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic ring structure.
Ar ²⁰² is an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic ring structure, or an optionally substituted aliphatic hydrocarbon structure represents
The substituents bonded to ring A1, the substituents bonded to ring A2, or the substituents bonded to ring A1 and the substituents bonded to ring A2 may be bonded 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 forming a bidentate ligand together with B ²⁰¹ and B ²⁰² . When there are multiple groups of B ²⁰¹ -L ²⁰⁰ -B ²⁰² , they may be the same or different.

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

(substituent)
Unless otherwise specified, a group selected from the following Substituent Group S is preferable as the substituent in the material for forming the light-emitting layer.

<Substituent group S>
- an alkyl group, preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably an alkyl group having 1 to 6 carbon atoms .
- An alkoxy group, preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and still more preferably an alkoxy group having 1 to 6 carbon atoms.
- an aryloxy group, preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, still more preferably an aryloxy group having 6 to 12 carbon atoms, particularly preferably an aryloxy group having 6 carbon atoms; aryloxy group.
- A 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.
• an aralkyl group, preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, and still more preferably an aralkyl group having 7 to 12 carbon atoms;
- a heteroaralkyl group, preferably a heteroaralkyl group having 7 to 40 carbon atoms, more preferably a heteroaralkyl group having 7 to 18 carbon atoms,
- an 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;
- An 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 .
- a 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 3 to 3 carbon atoms 14 heteroaryl groups.
An alkylsilyl group, preferably an alkylsilyl group having 1 to 20 carbon atoms, more preferably an alkylsilyl group having 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;
- an 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 fluorine atoms, or one or more hydrogen atoms may be replaced with deuterium atoms.
Unless otherwise specified, aryl is an aromatic hydrocarbon ring and heteroaryl is a heteroaromatic ring.
- A hydrogen atom, a deuterium atom, a fluorine atom, a cyano group, or -SF ₅ .

Of the substituent group S, preferably an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkylsilyl group, an arylsilyl group, and groups thereof 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, heteroaryl groups, and groups in which one or more hydrogen atoms of these groups are replaced with fluorine atoms, fluorine atoms, cyano a group, or —SF ₅ ,
more preferably an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkylsilyl group, an arylsilyl group,
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 groups S may further have a substituent selected from the substituent group S as a substituent. Preferred groups, more preferred groups, further preferred groups, particularly preferred groups, and most preferred groups of the substituents which may be present are the same as the preferred groups in the substituent group S.

(Ring A1)
Ring A1 represents an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic ring structure.

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

As the aromatic heterocyclic ring, an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom is preferable. Further preferred are furan ring, benzofuran ring, thiophene ring and 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, most preferably a benzene ring.

(Ring A2)
Ring A2 represents an aromatic heterocyclic structure which may have a substituent.
The aromatic heterocyclic ring is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms containing 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, 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, more preferably is pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, most preferably pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, quinoxaline ring, quinazoline ring .

(Combination of Ring A1 and Ring A2)
Preferred combinations of ring A1 and ring A2 are represented by (ring A1-ring A2), (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).

(Ring A1, substituent of ring A2)
The substituents that the ring A1 and the ring A2 may have may be optionally selected, but one or more substituents selected from the substituent group S are preferable.

( ^Ar201 , ^Ar202 , ^Ar203 )
Ar ²⁰¹ and Ar ²⁰³ each independently represent an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic ring structure.
Ar ²⁰² is an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic ring structure, or an optionally substituted aliphatic hydrocarbon structure represents

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

When either Ar ²⁰¹ or Ar ²⁰² is an optionally substituted benzene ring, at least one benzene ring is preferably bonded to the adjacent structure at the ortho- or meta-position. More preferably, one benzene ring is attached to the adjacent structure at the meta position.

When any of Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ is a fluorene ring optionally having a substituent, the 9- and 9′-positions of the fluorene ring have a substituent or are bonded to the adjacent structure. preferably.

When any one 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 heterocyclic ring having 3 to 30 carbon atoms containing any of a sulfur atom, specifically, a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, and a benzothiazole ring. , benzoxazole ring, benzimidazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, naphthyridine ring, phenanthridine ring, carbazole ring, dibenzofuran ring, and dibenzothiophene ring, preferably pyridine ring and 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 optionally having 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 optionally substituted aliphatic hydrocarbon structure, it is an aliphatic hydrocarbon structure having a linear, branched or cyclic structure, preferably having 1 to 24 carbon atoms. more preferably 1 or more and 12 or less carbon atoms, more preferably 1 or more and 8 or less carbon atoms.

(i1, i2, i3, i4, k1, k2)
i1 and i2 each independently represent an integer of 0-12, preferably 1-12, more preferably 1-8, more preferably 1-6. Within this range, an improvement in solubility and an improvement in charge transport properties can be expected.
i3 preferably represents an integer of 0-5, more preferably 0-2, more preferably 0 or 1.
i4 preferably represents an integer of 0 to 2, more preferably 0 or 1.
Each of k1 and k2 independently represents an integer of preferably 0 to 3, more preferably 1 to 3, more preferably 1 or 2, and particularly preferably 1.

(Preferred substituents of Ar ²⁰¹ , Ar ²⁰² and 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. Group S, but more preferably unsubstituted (hydrogen atom), alkyl group or aryl group, particularly preferably unsubstituted (hydrogen atom) or alkyl group, most preferably unsubstituted (hydrogen atom ) or a tertiary butyl group, where the tertiary butyl group is substituted for Ar ²⁰³ if Ar ²⁰³ is present, Ar ²⁰² if Ar ²⁰³ is absent, or Ar ²⁰¹ if Ar ²⁰² and Ar ²⁰³ are absent. preferably.

(Preferred Embodiment of Compound Represented by Formula (201))
The compound represented by the formula (201) is preferably a compound satisfying any one or more of the following (I) to (IV).

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

(II) (phenylene)-aralkyl (alkyl)
A structure having an aromatic hydrocarbon group or 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, 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, i3 is 0 or 1, preferably Ar ²⁰¹ is the aromatic hydrocarbon structure It is a hydrogen structure, more preferably a structure in which 1 to 5 benzene rings are linked, more preferably one benzene ring.
Such a structure is expected to improve the solubility and the charge transport property.

(III) Dendron A structure in which a dendron is bound 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 the solubility and the charge transport property.

(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)
Although the phosphorescent material represented by the formula (201) is not particularly limited, the following are preferred.

A phosphorescent material represented by the following formula (205) is also preferable.

[In formula (205), ^M2 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, there are no ^R94 and ^R95 . ]

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

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

Furthermore, when T is a carbon atom, ^R94 and ^R95 each independently represent a substituent represented by the same examples as ^R92 and ^R93 . Also, when T is a nitrogen atom, there is no ^R94 or ^R95 directly bonded to said T. In addition, R ⁹² to R ⁹⁵ may further have a substituent. The substituents may be the substituents described above. Furthermore, any two or more groups selected from R ⁹² to R ⁹⁵ may be linked together 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, and particularly preferably 3,000 or less. Also, the molecular weight of the phosphorescent material is preferably 800 or more, more preferably 1000 or more, and even more preferably 1200 or more. It is believed that within this molecular weight range, the phosphorescent light-emitting material is not agglomerated and uniformly mixed with the charge-transporting material, making it possible to obtain a light-emitting layer with high light-emitting efficiency.

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

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

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

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

A hole-transporting material is a compound having a structure having excellent hole-transporting properties. A pyrene structure is preferable as a structure having excellent hole transport properties, and a carbazole structure, a dibenzofuran structure, or a triarylamine structure is more preferable.

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

Specific examples of condensed ring structures having three or more rings include anthracene structure, phenanthrene structure, pyrene structure, chrysene structure, naphthacene structure, triphenylene structure, fluorene structure, benzofluorene structure, indenofluorene structure, indolofluorene structure, Carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, dibenzothiophene structure and the like. 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, from the viewpoints of charge transportability and solubility. A carbazole structure or an indolocarbazole structure is more preferred from the viewpoint of durability against electric charges.

In the present invention, at least one of the charge-transporting materials in the light-emitting layer is preferably a material having a pyrimidine skeleton or a triazine skeleton, from the viewpoint of the durability of the organic electroluminescent device against charges.

The charge-transporting 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 having 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 still more preferably 10,000 or less. 000 or more and 100,000 or less.

From the viewpoints of ease of synthesis and purification, ease of designing electron-transporting performance and hole-transporting performance, and ease of viscosity adjustment when dissolved in a solvent, the charge-transporting material for the light-emitting layer is A low molecular weight is preferred. When the charge-transporting 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, preferably 300 or more, more preferably 350 or more, and still more preferably 400 or more.

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

In the above formula (211), Ar ²⁴¹ represents an optionally substituted aromatic hydrocarbon condensed ring structure, Ar ²⁴² and Ar ²⁴³ are each independently an optionally substituted alkyl group, represents an aromatic hydrocarbon group, a heteroaromatic group, or a group in which these are bonded. n41 is an integer of 1-4.

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 and the like. 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 ring structures include fluoranthene, pyrene and chrysene.

n41 is 1-4, preferably 1-3, more preferably 1-2, 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, most preferably a phenyl group. , is a naphthyl group.

The heteroaromatic group for Ar ²⁴² and Ar ²⁴³ is preferably a heteroaromatic group 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 still more preferably is a hydrocarbon group among preferred groups for the group S of substituents.

The charge-transporting material used together with the fluorescent light-emitting material is not particularly limited, but is preferably represented by the following formula (212).

In formula (212) above, R ²⁵¹ and R ²⁵² each independently represent a structure represented by formula (213), R ²⁵³ represents a substituent, and when there are multiple 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 to the anthracene ring of formula (212), Ar ²⁵⁴ and Ar ²⁵⁵ are each independently an aromatic hydrocarbon structure optionally having a substituent, or a substituted represents a heteroaromatic ring structure which may have a group, Ar ²⁵⁴ and Ar ²⁵⁵ may be the same or different when there are a plurality of each, n44 is an integer of 1 to 5, n45 is 0 to An integer of 5.

Ar ²⁵⁴ is preferably an optionally substituted monocyclic or condensed ring aromatic hydrocarbon structure having 6 to 30 carbon atoms, more preferably optionally substituted , is a monocyclic or condensed ring aromatic hydrocarbon structure having 6 to 12 carbon atoms.

Ar ²⁵⁵ is preferably an optionally substituted monocyclic or condensed ring aromatic hydrocarbon structure having 6 to 30 carbon atoms, or an optionally substituted carbon number of 6 to 30 is an aromatic heterocyclic ring structure that is a condensed ring of Ar ²⁵⁵ is more preferably an optionally substituted monocyclic or condensed ring aromatic hydrocarbon structure having 6 to 12 carbon atoms, or an optionally substituted C 12 It is an aromatic heterocyclic ring structure that is a condensed ring.

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

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

The molecular weights of the fluorescence-emitting material and charge-transporting material are preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less. Also, it is preferably 300 or more, more preferably 350 or more, and still more preferably 400 or more.
<Quantum dots>
The light-emitting layer preferably contains quantum dots as light-emitting substances. Quantum dots are luminescent semiconductor nanoparticles, typically ranging in diameter from 1 to 20 nm.

The quantum dots are preferably composed of II-VI group compounds, III-V group compounds, IV-VI group compounds, IV group elements, IV group compounds, or combinations thereof.

II-VI group compounds include CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HeSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HeZnSe, HeZnTe, MgZnSe, MgZnS, HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHg SeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe.

III-V compounds include GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, ALPSB, INGAP, Innp, Innas, Innsb, Inpasb, INPSB, GAALNAS, GAALNAS, GAALNSB, GAALPAS, GAALPSB, GAINNP, GAINNAS, GAINNSB, GAINNSB, GAINSB. Pas, GAINPSB, Inalnp, Inalnasb, Inalpasb, and Inalpsb are listed.

SNS, Sns, Snse, Snte, PBS, PBS, PBSE, PBSE, SnSes, Snset, SnSETE, SNSETE, PBSETE, PBSETE, SNPBSETE, SNPBSE, SNPBTE, SNPBSSE, SNPBSSE, SNPBSSE, SNPBSSE. , SnpbSete and Snpbste are listed.

Group IV elements include Si and Ge, and Group IV compounds include SiC and SiGe.

A quantum dot may have a homogeneous single structure or a core/shell dual structure. It may also have a triple or quadruple or more structure such as core/shell/shell. The materials that make up the core and shell consist of different compounds. In this case, the energy bandgap of the shell compound is preferably larger than the energy bandgap of the core compound. Specifically, structures such as ZnTeSe/ZnSe/ZnS, CdSe/ZnS, and InP/ZnS are preferred.

[Composition for forming a light-emitting layer containing quantum dots]
The method for forming the light-emitting layer containing quantum dots may be either a vacuum deposition method or a wet film formation method, but the wet film formation method is preferred. In the case of the wet film-forming method, the light-emitting layer is formed by coating and drying a composition for forming a light-emitting layer containing an organic solvent.
The composition for forming a light-emitting layer containing quantum dots contains quantum dots and an organic solvent.

(Organic solvent)
The organic solvent contained in the composition for forming a light-emitting layer containing quantum dots is a volatile liquid component used for forming a layer containing quantum dots by wet film formation.

The organic solvent is not particularly limited as long as it is an organic solvent in which the solute quantum dots are well dissolved.

Preferred organic solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin and methylnaphthalene; Halogenated aromatic hydrocarbons such as chlorobenzene and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3 - aromatic ethers such as dimethylanisole, 2,4-dimethylanisole and diphenyl ether; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate and n-butyl benzoate; Alicyclic ketones such as cyclohexanone, cyclooctanone and fenchone; Alicyclic alcohols such as cyclohexanol and cyclooctanol; Aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; Aliphatic alcohols such as butanol and hexanol; aliphatic ethers such as glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA);

Among these, alkanes, aromatic hydrocarbons, and aromatic esters are preferable from the viewpoint of viscosity and boiling point.

One type of these organic solvents may be used alone, or two or more types may be used in any combination and ratio.

The boiling point of the organic solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower. If the boiling point of the organic solvent is below this range, the film formation stability may decrease due to evaporation of the solvent from the composition for forming the light-emitting layer during wet film formation. If the boiling point of the organic solvent exceeds this range, there is a possibility that the film formation stability will decrease due to the solvent remaining after film formation during wet film formation.

(Content)
The content of quantum dots in the composition for forming a light-emitting layer containing quantum dots is usually 0.001% by mass or more, preferably 0.01% by mass or more, usually 30.0% by mass or less, preferably 20.0% by mass. % or less. By setting the content in this range, holes and electrons are efficiently injected from adjacent layers (for example, a hole-transporting layer and a hole-blocking layer) to the light-emitting layer, thereby reducing the driving voltage. can be done. In addition, 1 type of quantum dots may be contained in the composition for light emitting layer formation, and 2 or more types may be combined and contained.

The content of the organic solvent contained in the light-emitting layer-forming composition containing quantum dots is usually 10% by mass or more, preferably 50% by mass or more, particularly preferably 80% by mass or more, and usually 99.95% by mass or less. , preferably 99.9% by mass or less, particularly preferably 99.8% by mass or less. If the content of the organic solvent is at least the above lower limit, the composition will have an appropriate viscosity and coatability will be improved.

(other ingredients)
The composition for forming a light-emitting layer containing quantum dots may contain other compounds in addition to the above compounds, if necessary. Other compounds preferably include dibutylhydroxytoluene, which is known as an antioxidant, phenols such as dibutylphenol, and known charge-transporting compounds.

(Film formation method)
The method for forming the light-emitting layer containing quantum dots is preferably a wet film-forming method. The wet film-forming method is a method of applying a composition to form a liquid film, drying it to remove the organic solvent, and forming a light-emitting layer film. Examples of coating methods include spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet, nozzle printing, screen printing, and gravure. A wet film-forming method such as a printing method or a flexographic printing method is employed, and the coating film is dried to form a film. Among these coating methods, the spin coating method, the spray coating method, the inkjet method, the nozzle printing method, and the like are preferable. When manufacturing a quantum dot display device equipped with a quantum dot light-emitting element, an inkjet method or a nozzle printing method is preferable, and an inkjet method is particularly preferable.

Although the drying method is not particularly limited, natural drying, reduced pressure drying, heat drying, or reduced pressure drying while heating can be used as appropriate. Heat drying may be carried out in order to further remove residual organic solvent after natural drying or vacuum drying.

In the vacuum drying, it is preferable to reduce the pressure below the vapor pressure of the organic solvent contained in the composition for forming a light-emitting layer containing quantum dots.

When heating, the heating method is not particularly limited, but heating with a hot plate, heating in an oven, infrared heating, etc. can be used. The heating temperature is usually 80° C. or higher, preferably 100° C. or higher, more preferably 110° C. or higher, and preferably 200° C. or lower, more preferably 150° C. or lower.

The heating time is usually 1 minute or more, preferably 2 minutes or more, usually 60 minutes or less, preferably 30 minutes or less, and more preferably 20 minutes or less.

[Hole blocking layer]
A hole-blocking layer may be provided between the light-emitting layer 5 and an electron-injecting layer, which will be described later. The hole-blocking layer is a layer laminated on the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 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. Physical properties required for the material constituting the hole blocking layer include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and an excited triplet level (T ₁ ). is high.

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, and the like. mixed ligand complexes, bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolato) aluminum binuclear metal complexes such as metal complexes, distyrylbiphenyl derivatives and the like Styryl compounds (JP-A-11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole ( JP-A-7-41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), and the like. Furthermore, the compound having at least one pyridine ring substituted at the 2,4,6 positions described in WO 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 forming 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. .

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

Specific examples of the electron-transporting compound used in the electron-transporting layer include, for example, a metal complex such as an aluminum complex of 8-hydroxyquinoline (Japanese Patent Laid-Open 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 (US Patent No. 5645948), quinoxaline compounds (Japanese Patent Laid-Open No. 6-207169), phenanthroline derivatives (Japanese Patent Laid-Open No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyano Anthraquinonediimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

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

The electron transport layer 6 is formed on the hole blocking layer by a wet film forming method or a vacuum vapor deposition method in the same manner as described above. A vacuum deposition method is usually used.
In the present invention, as described above, the electron-transporting layer can be formed on the light-emitting layer containing a suitable material for forming the light-emitting layer 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 perform electron injection efficiently, it is preferable that the material forming the electron injection layer be a metal with a low work function. Examples thereof include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like. The film thickness is preferably 0.1 nm or more and 5 nm or less.

Furthermore, an organic electron-transporting material typified by a nitrogen-containing heterocyclic compound such as bathophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium or rubidium ( JP-A-10-270171, JP-A-2002-100478, JP-A-2002-100482, etc.) also improves electron injection and transport properties and achieves excellent film quality. It is preferable because it enables

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 the light emitting layer 5 or the hole blocking layer or the electron transport layer 6 thereon by a wet film forming method or a vacuum deposition method.
The details of the wet film formation method are the same as those of the light-emitting layer described above.

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

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

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

From the viewpoint 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 stacking a metal layer that has a high work function and is stable against the atmosphere on the cathode. Metals to be laminated include, for example, 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 electroluminescence device of the present invention may further have other layers as long as they do not significantly impair the effects of the present invention. That is, it may have any of the other layers described above between the anode and cathode.

[Other device configurations]
The organic electroluminescence device of the present invention has a structure opposite to that described above. It is also possible to laminate the injection layer and the anode in this order.

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

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

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

[Lighting device]
The lighting device (organic electroluminescent element lighting device) of the present invention comprises the organic electroluminescent element of the present invention. There are no particular restrictions on the type and structure of the lighting device of the present invention, and the device can be assembled using the organic electroluminescence device of the present invention in a conventional manner.

<Quantum dot display device>
The quantum dot display device (quantum dot light emitting device display device) of the present invention comprises the quantum dot light emitting device of the present invention. The type and structure of the quantum dot display device of the present invention are not particularly limited, and the quantum dot light emitting device of the present invention can be assembled according to a conventional method.

For example, referring to the method described in "Organic EL Display" (Ohmsha, August 20, 2004, Shizuo Tokito, Chihaya Adachi, Hideyuki Murata), the organic light-emitting layer is The quantum dot display device of the present invention can be formed by replacing with a light-emitting layer containing dots.

<Quantum dot illumination device>
The quantum dot lighting device (quantum dot light emitting element lighting device) of the present invention comprises the quantum dot light emitting device of the present invention. There are no particular restrictions on the type and structure of the quantum dot lighting device of the present invention, and it can be assembled using the quantum dot light emitting device of the present invention in accordance with conventional methods.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and the present invention can be arbitrarily modified without departing from the scope of the invention.

<Synthesis of intermediates>
[Synthesis of compound 1]

270 mL of toluene, 135 mL of ethanol, 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-dihexylfluorene (20. 0 g, 34.1 mmol), 50.72 g (136.5 mmol) of 5-bromo-2-iodotoluene, and 102 mL of an aqueous potassium phosphate solution (2 M, that is, 2 mol/liter concentration). replaced. Heated under a stream of nitrogen and stirred for 30 minutes. After that, 0.48 g (0.68 mmol) of bis(triphenylphosphine) palladium (II) dichloride was added and reacted at 65°C for 6 hours. Water was added to the reaction solution, extracted with toluene, and treated with MgSO ₄ and activated clay. After the toluene solution was heated under reflux, the insoluble matter was filtered and recrystallized to obtain compound 1 as a colorless solid (yield: 16.5 g, yield: 72.1%).

[Synthesis of compound 3]

Then 3-bromo-3′-iodo-1,1-biphenyl (29.4 g, 81.9 mmol), commercially available compound 2 (20.0 g, 81.9 mmol), potassium phosphate (2 M aqueous solution, 103 g, 205 mmol) ), toluene (200 mL), and ethanol (100 mL) were charged into a flask, the system was sufficiently purged with nitrogen, and heated to 60°C. Tetrakis(triphenylphosphine)palladium(0) (2.37 g, 2.05 mmol) was added and stirred at 85° C. for 6 hours. Water was added to the reaction solution, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was purified by column chromatography (developer: hexane/methylene chloride=950/50) to obtain compound 3 (23.1 g, yield 81%).

[Synthesis of Compound 4]

Compound 3 (23.1 g, 66.1 mmol), commercially available 3-aminophenylboronic acid (9.8 g, 63.0 mmol), potassium phosphate (2 M aqueous solution, 79 g, 158 mmol), and toluene (160 mL), ethanol ( 80 mL) was placed in a flask, the system was sufficiently purged with nitrogen, and heated to 60°C. Tetrakis(triphenylphosphine)palladium(0) (1.85 g, 1.6 mmol) was added and stirred at 85° C. for 4 hours. Water was added to the reaction solution, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was purified by column chromatography (developer: hexane/ethyl acetate=8/2) to obtain compound 4 (22.2 g, yield 92.9%).

[Synthesis of compound 5]
Compound 5 was synthesized by the method described in WO2020/171190.

<Synthesis of polymer compound>
[Synthesis of polymer compound P-1]
A polymer compound P-1 was synthesized according to the following reaction formula.

Compound 1 (2.0 g, 2.97 mmol), Compound 4 (1.1179 g, 3.09 mmol), 2,4-difluoroaniline (0.3686 g, 2.85 mmol), sodium tert-butoxy (2.2 g, 22.89 mmol) and toluene (40 g, 46 mL) were charged, the system was sufficiently purged with nitrogen, and heated to 60° C. (solution A1).

[4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0 .126 g, 0.47 mmol) was added and warmed to 60° C. (solution B1).

Solution B1 was added to solution A1 in a nitrogen stream, and the mixture was heated under reflux for 1.0 hour. After confirming that compound 1 had disappeared, 4,4'-dibromobiphenyl (0.668 g, 2.14 mmol) was added. After heating under reflux for 2 hours, bromobenzene (1.3 g, 8.2 mmol) was added and the reaction was carried out under heating under reflux for 2 hours. The reaction solution was allowed to cool and added dropwise to an ethanol/water (210 mL/30 mL) solution to obtain an end-capped crude polymer.

This end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The polymer collected by filtration was purified by column chromatography to obtain the target polymer compound P-1 (1.6 g). The molecular weight and the like of the obtained polymer compound P-1 were as follows.

Weight average molecular weight (Mw) = 16360
Number average molecular weight (Mn) = 11680
Dispersity (Mw/Mn) = 1.40

[Synthesis of polymer compound P-2]
A polymer compound P-2 was synthesized according to the following reaction formula.

Compound 1 (2.0 g, 2.97 mmol), Compound 4 (1.1179 g, 3.09 mmol), 3,5-difluoroaniline (0.3686 g, 2.85 mmol), sodium tert-butoxy (2.2 g, 22.89 mmol) and toluene (40 g, 46 mL) were charged, the system was sufficiently purged with nitrogen, and heated to 60° C. (solution A2).

[4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0 .126 g, 0.47 mmol) was added and warmed to 60° C. (solution B2).

Solution B2 was added to solution A2 in a nitrogen stream, and the mixture was heated under reflux for 1.0 hour. After confirming that compound 1 had disappeared, 4,4'-dibromobiphenyl (0.668 g, 2.14 mmol) was added. After heating under reflux for 2 hours, bromobenzene (1.3 g, 8.2 mmol) was added and the reaction was carried out under heating under reflux for 2 hours. The reaction solution was allowed to cool and added dropwise to an ethanol/water (210 mL/30 mL) solution to obtain an end-capped crude polymer.

This end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The polymer collected by filtration was purified by column chromatography to obtain the target polymer compound P-2 (1.5 g). The molecular weight and the like of the obtained polymer compound P-2 were as follows.

Weight average molecular weight (Mw) = 13610
Number average molecular weight (Mn) = 10230
Dispersity (Mw/Mn) = 1.33

[Synthesis of polymer compound P-3]
A polymer compound P-3 was synthesized according to the following reaction formula.

4,4′-dibromobiphenyl (2.56 g, 8.21 mmol), compound 4 (1.9465 g, 5.38 mmol), 3,5-difluoroaniline (0.96 g, 7.44 mmol), sodium tert-butoxy (4.75 g, 49.43 mmol) and toluene (40 g, 46 mL) were charged, the system was sufficiently purged with nitrogen, and heated to 60° C. (solution A3).

[4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.272 g) was added to a toluene 20 mL solution of tris(dibenzylideneacetone) dipalladium complex (0.1174 g, 0.13 mmol). , 1.02 mmol) and warmed to 60° C. (solution B3).

Solution B3 was added to solution A3 in a nitrogen stream, and the mixture was heated under reflux for 2.0 hours. After confirming that 4,4′-dibromobiphenyl had disappeared, compound 1 (1.811 g, 2.69 mmol) was added. After heating under reflux for 2 hours, bromobenzene (3.0 g, 19.11 mmol) was added, and the reaction was carried out under heating under reflux for 2 hours. The reaction solution was allowed to cool and added dropwise to an ethanol/water (255 mL/60 mL) solution to obtain an end-capped crude polymer.

This end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The filtered polymer was purified by column chromatography to obtain the target polymer compound P-3 (2.1 g). The molecular weight and the like of the obtained polymer compound P-3 were as follows.

Weight average molecular weight (Mw) = 11250
Number average molecular weight (Mn) = 8272
Dispersity (Mw/Mn) = 1.36

[Synthesis of polymer compound P-4]
A polymer compound P-4 was synthesized according to the following reaction formula.

4,4′-dibromobiphenyl (3.0 g, 9.62 mmol), compound 4 (1.5294 g, 4.23 mmol), 3,5-difluoroaniline (1.5642 g, 12.12 mmol), 2-amino- 9,9′-Dihexylfluorene (1.0083 g, 2.88 mmol), tert-butoxysodium (7.12 g, 74.09 mmol) and toluene (45 g, 52 mL) were charged, and the inside of the system was sufficiently replaced with nitrogen, Warmed to 60° C. (solution A4).

[4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.408 g) was added to a solution of tris(dibenzylideneacetone) dipalladium complex (0.1761 g, 0.192 mmol) in 30 mL of toluene. , 1.54 mmol) and warmed to 60° C. (solution B4).

Solution B4 was added to solution A4 in a nitrogen stream, and the mixture was heated under reflux for 1.0 hour. After confirming that 4,4'-dibromobiphenyl had disappeared, 4,4'-dibromobiphenyl (2.415 g, 7.74 mmol) was added. After heating under reflux for 2 hours, bromobenzene (2.94 g, 18.7 mmol) was added and the reaction was carried out under heating under reflux for 2 hours. The reaction solution was allowed to cool and added dropwise to an ethanol/water (315 mL/50 mL) solution to obtain an end-capped crude polymer.

This end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The polymer collected by filtration was purified by column chromatography to obtain the target polymer compound P-4 (2.1 g). The molecular weight and the like of the obtained polymer compound P-4 were as follows.

Weight average molecular weight (Mw) = 13500
Number average molecular weight (Mn) = 9854
Dispersity (Mw/Mn) = 1.37

[Synthesis of polymer compound Pa]
Polymer compound Pa was synthesized according to the following reaction scheme.

4,4′-dibromo-p-terphenyl (3.0 g, 7.73 mmol), 2-amino-9,9-dihexylfluorene (2.205 g, 6.31 mmol), compound 5 (0.565 g, 1 .42 mmol), 3,5-difluoroaniline (0.998 g, 7.73 mmol), tert-butoxysodium (5.73 g, 59.63 mmol) and toluene (83 ml) were charged, and the system was sufficiently replaced with nitrogen. and heated to 60° C. (solution A5).

[4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0 .328 g, 1.24 mmol) was added and warmed to 60° C. (solution B5).

Solution B5 was added to solution A5 in a nitrogen stream, and the mixture was heated under reflux for 1.0 hour. After confirming that compound 5 had disappeared, 2,7-bis(4-bromophenyl)9,9-dihexylfluorene (3.54 g, 5.49 mmol) was added. After heating under reflux for 2 hours, bromobenzene (3.52 g, 22.42 mmol) was added, and the reaction was heated under reflux for 2 hours. The reaction mixture was allowed to cool and added dropwise to an ethanol/water (275 ml/50 ml) solution to obtain an end-capped crude polymer.

This end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The filtered polymer was purified by column chromatography to obtain the target polymer compound Pa (2.0 g). The molecular weight and the like of the obtained polymer compound Pa were as follows.
Weight average molecular weight (Mw) = 18320
Number average molecular weight (Mn) = 14774
Dispersity (Mw/Mn) = 1.24

[Synthesis of polymer compound P-5]

A polymer compound P-5 was synthesized in the same manner as the polymer compound P-1.

[Production of organic electroluminescent device]
[Example 1]
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate to a thickness of 50 nm (manufactured by Geomatec, a sputter-deposited product) was subjected to a 2 mm-wide stripe using ordinary photolithography and etching with hydrochloric acid. was patterned to form an anode. The substrate on which the ITO pattern is formed in this manner is washed with ultrasonic waves using an aqueous solution of surfactant, washed with ultrapure water, ultrasonically washed with ultrapure water, and washed with ultrapure water in this order, and then dried with compressed air. , and finally performed ultraviolet ozone cleaning.

As a composition for forming a hole injection layer, 3.1% by mass of a hole-transporting polymer compound having a structure of the following formula (P-1) and 0.6% by mass of an electron-accepting compound (HI-1) below. was dissolved in ethyl benzoate to prepare a composition.

This composition was spin-coated on the 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 40 nm, which was used as a hole injection layer.

Next, 100 parts by mass of a charge-transporting polymer compound having the following structural formula (HT-1) was dissolved in 1,3,5-trimethylbenzene to prepare a 2.0% by mass 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. was formed to form a hole transport layer.

Next, a host compound having the following structural formula (BH-1) and a dopant compound having the following structural formula (BD-1) were dissolved in cyclohexylbenzene in parts by weight of 100:10 to give 4.4% by weight. was prepared.

A uniform thin film of 40 nm was formed by spin coating in a nitrogen glove box on the substrate on which the film up to the hole transport layer had been applied and formed as a light-emitting layer. It was dried on a hot plate in a nitrogen glove box at 120° C. for 20 minutes to form a light-emitting layer.

The substrate on which up to the light-emitting layer was formed was placed in a vacuum deposition apparatus, and the inside of the apparatus was evacuated to 2×10 ⁻⁴ Pa or less.

Next, a compound represented by the following structural formula (ET-1) and 8-hydroxyquinolinolatritium are co-deposited on the light-emitting layer at a film thickness ratio of 2:3 by a vacuum vapor deposition method to obtain a film thickness. A 30 nm electron transport layer was formed.

Subsequently, a striped shadow mask with a width of 2 mm was adhered to the substrate so as to be orthogonal to the ITO stripes of the anode as a mask for cathode evaporation, and aluminum was heated by a molybdenum boat by vacuum evaporation to obtain a film thickness of 80 nm. was formed to form a cathode. As described above, an organic electroluminescence device having a light-emitting area of 2 mm×2 mm was obtained.

In a space filled with nitrogen, a moisture and oxygen adsorbent is attached to the inside of a glass substrate having a hollow structure, and the surface of the glass substrate having the organic electroluminescent element and the moisture and oxygen adsorbent of the hollow glass are provided. The surfaces were made to face each other, and an ultraviolet curable resin was applied so as to surround the outer periphery of the organic electroluminescence element portion, and the surfaces were bonded to each other. Further, a structure was formed in which the ultraviolet curable resin portion was irradiated with ultraviolet rays to isolate the organic electroluminescence element portion from the external space. As a result, the surface of the organic electroluminescent device can be isolated from moisture and oxygen without any structure directly touching it, and the performance of the organic electroluminescent device can be evaluated by excluding the influence of moisture and oxygen. be able to.

[Example 2]
As the composition for forming a hole injection layer, 3.1% by mass of the hole-transporting polymer compound having the structure of the formula (P-2) and 0.6% by mass of the electron-accepting compound (HI-1) alone. An organic electroluminescence device was produced in the same manner as in Example 1, except that a composition dissolved in ethyl benzoate was prepared and used.

[Example 3]
As a composition for forming a hole injection layer, 3.1% by mass of a hole-transporting polymer compound having the structure of formula (P-4) and 0.6% by mass of an electron-accepting compound (HI-1) are mixed. An organic electroluminescence device was produced in the same manner as in Example 1, except that a composition dissolved in ethyl benzoate was prepared and used.

[Comparative Example 1]
As a composition for forming a hole injection layer, 3.1% by mass of a hole-transporting polymer compound having a structure of the above formula P-5 and 0.6% by mass of an electron-accepting compound (HI-1) are combined with benzoin. An organic electroluminescence device was produced in the same manner as in Example 1, except that a composition dissolved in ethyl acetate was prepared and used.

[Evaluation of fluorescent element]
When the organic electroluminescent devices obtained in Examples 1 to 3 and Comparative Example 1 were caused to emit light, blue light emission with a peak wavelength of 468 nm was obtained. Driving voltage (V) and current efficiency (cd/A) were measured when the organic electroluminescence device was caused to emit light at 1,000 cd/m ² . In addition, the luminance reduction lifetime (luminance reduction of 95%) was measured when the organic electroluminescence device was continuously energized at a current density of 15 mA/cm ² .

When the driving voltage (V) of the organic electroluminescent device of Comparative Example 1 was set to 0.00 V, the difference in the driving voltages of the organic electroluminescent devices of the other examples and of Comparative Example 1 (hereinafter referred to as "relative voltage" ) are listed in Table 1.

When the current luminous efficiency (cd/A) of the organic electroluminescence device of Comparative Example 1 is 1.00, the ratio of the current luminous efficiencies of the organic electroluminescence devices of other examples and comparative examples, that is, “comparative example Table 1 shows the current luminescence efficiency of each organic electroluminescence device other than No. 1/current luminescence efficiency of the organic electroluminescence device of Comparative Example 1 (hereinafter referred to as "relative current luminescence efficiency").

In addition, the time (hr) for the brightness of the device to decrease to 95% of the initial brightness was measured when a current density of 15 mA/cm ² was continuously applied to these organic electroluminescence devices. Let this value be LT95. When the LT95 of the organic electroluminescent device of Comparative Example 1 is set to 1.00, the ratio of LT95 of the organic electroluminescent devices of other examples and comparative examples, that is, “of each organic electroluminescent device other than Comparative Example 1 LT95/LT95 of the organic electroluminescence device of Comparative Example 1 (hereinafter referred to as “relative life”) was determined and shown in Table 1.

From the results in Table 1, the voltage of the blue fluorescent organic electroluminescent device formed using the composition of the present invention containing the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound having a cross-linking group is low. It was found that the current luminous efficiency and life were good.

[Example 4]
An electroluminescence device was produced in the same manner as in Example 1, except that the structure of the light emitting layer in Example 1 was changed to the light emitting layer 5 as described below.

In forming the light-emitting layer 5, 25 parts by mass of the compound (GH-1) represented by the following structural formula, 25 parts by mass of the compound (GH-2) represented by the following structural formula, and the following structural formula 50 parts by mass of the compound (GH-3) represented by and 30 parts by mass of the compound (GD-1) represented by the following structural formula were weighed and dissolved in cyclohexylbenzene to obtain a 7.02% by mass solution. prepared.

This solution was spin-coated in a nitrogen glove box onto the substrate on which the hole transport layer had been applied 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 5 was formed.

[Example 5]
An organic electroluminescence device was produced in the same manner as in Example 4 except that the compound represented by the above formula (P-1) was changed to the compound represented by the above formula (P-2).

[Example 6]
An organic electroluminescence device was produced in the same manner as in Example 4, except that the compound represented by the above formula (P-1) was changed to the compound represented by the above formula (P-4).

[Comparative Example 2]
An organic electroluminescence device was produced in the same manner as in Example 4, except that the compound represented by the above formula (P-1) was changed to the compound represented by the above formula (P-5).

[Evaluation of phosphorescent element]
When the organic electroluminescence devices obtained in Examples 4 to 6 and Comparative Example 2 were caused to emit light, green phosphorescence emission with a peak wavelength of 524 nm was obtained. Driving voltage (V) and current efficiency (cd/A) were measured when the organic electroluminescence device was caused to emit light at 1,000 cd/m ² . In addition, the luminance reduction lifetime (luminance reduction of 95%) was measured when the organic electroluminescence device was continuously energized at a current density of 15 mA/cm ² .

When the driving voltage (V) of the organic electroluminescent device of Comparative Example 2 was set to 0.00 V, the difference in the driving voltages of the organic electroluminescent devices of the other examples and of Comparative Example 2 (hereinafter referred to as "relative voltage" ) are listed in Table 2.

When the current luminous efficiency (cd/A) of the organic electroluminescent device of Comparative Example 2 is 1.00, the ratio of the current luminous efficiency of the organic electroluminescent devices of other examples and comparative examples, i.e., "comparative example Table 2 shows the current luminescence efficiency of each organic electroluminescence device other than Example 2/current luminescence efficiency of the organic electroluminescence device of Comparative Example 2 (hereinafter referred to as "relative current luminescence efficiency").

In addition, the time (hr) for the brightness of the device to decrease to 95% of the initial brightness was measured when a current density of 15 mA/cm ² was continuously applied to these organic electroluminescence devices. Let this value be LT95. When the LT95 of the organic electroluminescent device of Comparative Example 2 is set to 1.00, the ratio of LT95 of the organic electroluminescent devices of other examples and comparative examples, that is, “of each organic electroluminescent device other than Comparative Example 2 LT95/LT95 of the organic electroluminescence device of Comparative Example 1 (hereinafter referred to as “relative life”) was obtained and shown in Table 2.

From the results in Table 2, the green phosphorescent organic electroluminescent device formed using the composition of the present invention containing the fluorine-containing arylamine polymer compound of the present invention and the electron-accepting compound having a cross-linking group exhibited a low voltage. It was found that the current luminous efficiency and life were good.

[Example 7]
As an electron-accepting compound contained in the composition for forming a hole injection layer, a compound represented by the following formula (HI-2) instead of the compound represented by the above formula (HI-1) is used for hole injection. A layer-forming composition was prepared, and an organic electroluminescence device was produced in the same manner as in Example 4, except that this composition was used.

[Comparative Example 3]
As an electron-accepting compound contained in the composition for forming a hole injection layer, a compound represented by the following formula (HI-3) instead of the compound represented by the above formula (HI-2) is used for hole injection. A layer-forming composition was prepared, and an organic electroluminescence device was produced in the same manner as in Example 7, except that this composition was used.

[Example 8]
Using the compound represented by the above formula (P-2) instead of the compound represented by the above formula (P-1) as the hole-transporting polymer compound contained in the composition for forming a hole injection layer A composition for forming a hole injection layer was prepared, and an organic electroluminescence device was produced in the same manner as in Example 7, except that this composition was used.

[Comparative Example 4]
Hole injection using the compound represented by the above formula (HI-3) instead of the compound represented by the above formula (HI-2) as the electron-accepting compound contained in the composition for forming a hole injection layer A layer-forming composition was prepared, and an organic electroluminescence device was produced in the same manner as in Example 8, except that this composition was used.

[Example 9]
Using the compound represented by the above formula (P-4) instead of the compound represented by the above formula (P-1) as the hole-transporting polymer compound contained in the composition for forming a hole injection layer A composition for forming a hole injection layer was prepared, and an organic electroluminescence device was produced in the same manner as in Example 7, except that this composition was used.

[Comparative Example 5]
Hole injection using the compound represented by the above formula (HI-3) instead of the compound represented by the above formula (HI-2) as the electron-accepting compound contained in the composition for forming a hole injection layer A layer-forming composition was prepared, and an organic electroluminescence device was produced in the same manner as in Example 9, except that this composition was used.

[Example 10]
As a hole-transporting polymer compound contained in the composition for forming a hole injection layer, a compound represented by the following formula (Pa) is used instead of the compound represented by the above formula (P-1). A composition for forming a hole injection layer was prepared, and an organic electroluminescence device was produced in the same manner as in Example 4, except that this composition was used.

[Evaluation of element]
The organic electroluminescence devices obtained in Examples 7, 8, 9, 10, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Comparative Example 5 were caused to emit light at 1,000 cd/m ² . The actual current efficiency (cd/A) was measured. Further, the time (hr) for the brightness of the device to decrease to 95% of the initial brightness was measured when the organic electroluminescence device was continuously energized at a current density of 15 mA/cm ² . Let this value be LT95.
When the current luminous efficiency (cd/A) of the organic electroluminescent device of Comparative Example 4 is 1.00, the ratio of the current luminous efficiencies of the organic electroluminescent devices of Examples and Comparative Examples, that is, “Example or Table 3 shows the current luminous efficiency of the organic electroluminescent device of Comparative Example/current luminous efficiency of the organic electroluminescent device of Comparative Example 4 (hereinafter referred to as "relative current luminous efficiency").
When the LT95 of the organic electroluminescent device of Comparative Example 4 is set to 1.00, the ratio of the LT95 of the organic electroluminescent devices of Examples and Comparative Examples, that is, the LT95 of the organic electroluminescent devices of Examples and Comparative Examples, respectively / LT95 of the organic electroluminescence device of the comparative example (hereinafter referred to as "relative life") was determined and shown in Table 3.

From the results in Table 3, it was found that the phosphorescent organic electroluminescent device using the fluorine-free polymer compound and the electron-accepting compound not containing the cross-linking group has the fluorine-containing arylamine polymer compound of the present invention and the cross-linking group. It was found that the phosphorescent organic electroluminescent device formed using the composition of the present invention containing an electron-accepting compound exhibits good current luminescence efficiency and lifetime.

<Method for measuring ionization potential>
Ionization potential (IP) measurements are performed by photoelectron yield spectroscopy (PYS). The measurement is preferably performed using PCR-101 manufactured by Optel, but is not limited as long as equivalent measurement can be performed.
Specifically, a sample coating liquid is prepared by dissolving the host material in a suitable solvent. The solvent is not limited, and those exemplified as the solvent used for the composition for forming the light-emitting layer can be used, but the solvent used when actually forming the light-emitting layer is preferable.

Although the concentration of the sample coating liquid is not particularly limited, it may be a concentration at which a film thickness of 50 nm is formed after film formation and drying.
A film is formed on a quartz substrate from the prepared sample coating liquid. The film formation is preferably performed in the same manner as the method described in the film formation process of the light-emitting layer.

After the film is formed, it is dried to obtain a sample for measurement with a film thickness of 50 nm. Drying is also preferably carried out in the same manner as described in the step of drying the light-emitting layer.
This measurement sample is set on a substrate holder in the measurement chamber of the measurement device (Optel PCR-101), and the door of the measurement chamber is closed. The measuring chamber is evacuated to below 10 ⁻¹ Pa by a turbomolecular pump. A voltage of −50 V is applied to the sample, the excitation light from the deuterium lamp is made monochromatic and is incident on the sample, and the photoelectrons emitted from the sample due to the excitation are detected by a microammeter. The ionization potential is determined from a plot of monochromatic excitation light energy versus photoelectron detection.

As for the energy gap (Eg), the prepared sample is used to measure the absorption curve of the thin film with an ultraviolet-visible spectrophotometer as described in <Method for Measuring Ionization Potential>. A tangent line is drawn at the short-wavelength side rise of the thin film, and the obtained wavelength (λ) nm at the crossing point is substituted into the following equation to obtain the target value. The value thus obtained is Eg (eV).
Eg=1240/λ
For example, if the λ value obtained by drawing the tangent line is 450 nm, the Eg value at this time is Eg=1240/450=2.76 (eV)
I will say.
Ea (electron affinity) is Ip minus Eg.
The absolute value of the HOMO energy level corresponds to the ionization potential, and the absolute value of the LUMO energy level corresponds to the electron affinity. , P-2, P-3, P-4, Pa and P-5 are shown in Table 4.

From the results in Table 4, the HOMO of the fluorine-containing arylamine polymer compound of the present invention is deeper than that of the fluorine-free polymer P-5. A high current luminous efficiency and lifetime can be expected.

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

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2022-027242) filed on February 24, 2022, the contents of which are incorporated herein by reference.

REFERENCE SIGNS LIST 1 substrate 2 anode 3 hole injection layer 4 hole transport layer 5 light emitting layer 6 electron transport layer 7 cathode 8 organic electroluminescence device

Claims

A polymer compound having a repeating unit represented by the following formula (1), having a fluorene which may have a substituent in at least one of the main chain and the side chain, and having a cross-linking group; and A composition comprising an electron-accepting compound having a cross-linking group represented by (81).

(In formula (1),
Ar 1 is an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, or an optionally substituted divalent aromatic heterocyclic ring having 3 to 50 carbon atoms. or a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group ,
G represents a divalent group represented by any one of formulas (1-1) to (1-3),
"*" represents the bonding position with the adjacent structure,
Each substituent A is independently a fluorine atom, CF3 , or SF5 .
Ar 2 is a hydrogen atom, a substituent A, an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heteroaromatic group having 3 to 50 carbon atoms. A plurality of groups selected from a cyclic group, an optionally substituted aromatic hydrocarbon group, and an optionally substituted aromatic heterocyclic group are linked directly or via a linking group. represents a monovalent group,
m is an integer from 1 to 4,
n is an integer of 1-6. )

(In formula (81),
5 R 81 , 5 R 82 , 5 R 83 and 5 R 84 are each independently, and R 81 to R 84 are each independently hydrogen atom, deuterium atom, halogen atom, optionally substituted aromatic hydrocarbon group having 6 to 50 carbon atoms, aromatic heterocyclic group having 3 to 50 carbon atoms optionally having substituent(s), fluorine-substituted 1 to 1 carbon atoms 12 alkyl groups or bridging groups.
Ph 1 , Ph 2 , Ph 3 and Ph 4 are symbols indicating respective benzene rings.
X + represents a counter cation. )
The composition according to claim 1, comprising an electron-accepting compound represented by the formula (81) having at least two cross-linking groups.
The composition according to claim 1 or 2, wherein the compound represented by the formula (1) and the compound represented by the formula (81) each independently have a cross-linking group selected from the following cross-linking group group T thing.
<Crosslinking Group T>

(In the above formula,
Q represents a direct bond or a linking group.
"*" represents the binding position.
R 110 in formula (X4), formula (X5), formula (X6) and formula (X10) represents a hydrogen atom or an optionally substituted alkyl group.
In formulas (X1) to (X4), the benzene ring and naphthalene ring may have a substituent. Also, the substituents may be combined with each other to form a ring.
In formulas (X1) and (X2), the cyclobutene ring may have a substituent. )
The composition according to any one of claims 1 to 3, wherein G is represented by any of the following formulas.

(In the above formula, "*" represents the bonding position with the adjacent structure.)
The composition according to any one of claims 1 to 3, wherein [-G-Ar 2 ] is represented by any one of the following formulae.

(In the above formula, "*" represents the bonding position with the adjacent structure.)
Ar 1 has one partial structure selected from the following formulas (2-1) to (2-3), or 2 selected from the following formulas (2-1) to (2-3) or more bonded to each other, and the bonded structure contains a structure in which two or more of at least one structure selected from the following formulas (2-1) to (2-3) are bonded. Good, the composition according to any one of claims 1-5.

(In each of the above formulas (2-1) to (2-3), R 1 and R 2 each independently represent a hydrogen atom, a deuterium atom, a halogen atom, or an optionally substituted carbon number of 6 ~18 aromatic hydrocarbon groups, optionally substituted C3-C12 aromatic heterocyclic groups, C1-C12 alkyl groups, and "*" with the adjacent structure represents the binding position.)
The composition according to any one of claims 1 to 6, wherein the polymer compound further has a repeating unit represented by the following formula (3).

(In the above formula (3), Ar 3 is an optionally substituted 2-fluorenyl group. Ar 4 is an optionally substituted divalent aromatic hydrocarbon group, A divalent aromatic heterocyclic group which may have a substituent, or a divalent aromatic hydrocarbon group which may have a substituent and a divalent which may have a substituent represents a divalent group in which at least two groups selected from the group consisting of aromatic heterocyclic groups are linked directly or via a linking group.)
The composition according to any one of claims 1 to 7, further comprising a solvent.
A method for producing an organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, comprising:
A method for producing an organic electroluminescence device, comprising the step of forming the organic layer by a wet film-forming method using the composition according to claim 8 .
The method for manufacturing an organic electroluminescence device according to claim 9, wherein the organic layer is an organic layer between the anode and the light-emitting layer.
An organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,
The organic layer has a repeating unit represented by the following formula (1), has fluorene which may have a substituent in at least one of the main chain and the side chain, and has a cross-linking group. An organic electroluminescence device containing a cross-linking reaction product of a compound and an electron-accepting compound having a cross-linking group represented by the following formula (81).

(In formula (1),
Ar 1 is an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, or an optionally substituted divalent aromatic heterocyclic ring having 3 to 50 carbon atoms. or a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group ,
G represents a divalent group represented by any one of formulas (1-1) to (1-3),
"*" represents the binding site with the adjacent structure,
Each substituent A is independently a fluorine atom, CF3 , or SF5 .
Ar 2 is a hydrogen atom, a substituent A, an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heteroaromatic group having 3 to 50 carbon atoms. A plurality of groups selected from a cyclic group, an optionally substituted aromatic hydrocarbon group, and an optionally substituted aromatic heterocyclic group are linked directly or via a linking group. represents a monovalent group,
m is an integer from 1 to 4,
n is an integer of 1-6. )

(In formula (81),
5 R 81 , 5 R 82 , 5 R 83 and 5 R 84 are each independently, and R 81 to R 84 are each independently hydrogen atom, deuterium atom, halogen atom, optionally substituted aromatic hydrocarbon group having 6 to 50 carbon atoms, aromatic heterocyclic group having 3 to 50 carbon atoms optionally having substituent(s), fluorine-substituted 1 to 1 carbon atoms 12 alkyl groups or bridging groups.
Ph 1 , Ph 2 , Ph 3 and Ph 4 are symbols indicating respective benzene rings.
X + represents a counter cation. )
12. The organic electroluminescence device according to claim 11, wherein said G is represented by any one of the following formulae.

(In the above formula, "*" represents the bonding position with the adjacent structure.)
12. The organic electroluminescence device according to claim 11, wherein [-G-Ar 2 ] is represented by any one of the following formulae.

(In the above formula, "*" represents the bonding position with the adjacent structure.)
Ar 1 has one partial structure selected from the following formulas (2-1) to (2-3), or 2 selected from the following formulas (2-1) to (2-3) or more bonded to each other, and the bonded structure contains a structure in which two or more of at least one structure selected from the following formulas (2-1) to (2-3) are bonded. The organic electroluminescence device according to any one of claims 11 to 13.

(In each of the above formulas (2-1) to (2-3), R 1 and R 2 are each independently a hydrogen atom, a deuterium atom, a halogen atom, or the number of carbon atoms which may have a substituent. an aromatic hydrocarbon group of 6 to 18, an aromatic heterocyclic group of 3 to 12 carbon atoms which may have a substituent, an alkyl group of 1 to 12 carbon atoms, and * is a bond with an adjacent structure position.)
The organic electroluminescence device according to any one of claims 11 to 14, wherein the polymer compound further has a repeating unit represented by the following formula (3).

(In formula (3), Ar 3 is an optionally substituted 2-fluorenyl group. Ar 4 is an optionally substituted divalent aromatic hydrocarbon group, a substituted a divalent aromatic heterocyclic group optionally having a group, or a divalent aromatic hydrocarbon group optionally having a substituent and a divalent It represents a divalent group in which at least two groups selected from the group consisting of aromatic heterocyclic groups are linked directly or via a linking group.)
An organic electroluminescent device manufactured by the method for manufacturing an organic electroluminescent device according to claim 9 or 10.
The organic electroluminescence device according to any one of claims 11 to 16, which contains quantum dots in the light-emitting layer.
A display device comprising the organic electroluminescence device according to any one of claims 11 to 17.
A lighting device comprising the organic electroluminescence device according to any one of claims 11 to 17.