WO2020122113A1

WO2020122113A1 - Charge-transporting varnish

Info

Publication number: WO2020122113A1
Application number: PCT/JP2019/048452
Authority: WO
Inventors: 倉田　陽介
Original assignee: 日産化学株式会社
Priority date: 2018-12-13
Filing date: 2019-12-11
Publication date: 2020-06-18
Also published as: JP7351314B2; TWI828821B; JPWO2020122113A1; TW202031807A

Abstract

A charge transporting varnish, which comprises a charge-transporting material, a high-molecular compound represented by formula (I) and an organic solvent, can provide a highly solvent-resistant thin film. By applying this thin film to a hole injection layer, etc., an organic EL element having excellent characteristics can be realized. (Ra1 to Ra8 independently represent a hydrogen atom, an alkyl group having 1-20 carbon atoms, an alkenyl group having 2-20 carbon atoms, an aryl group having 6-20 carbon atoms, etc., provided that Ra4 and Ra8 may be bonded to each other to form a single bond, etc.; Rb1 represents an aryl group having 6-20 carbon atoms or a heteroaryl group having 2-20 carbon atoms; Rb2 represents an alkyl group having 1-20 carbon atoms, an aryl group having 6-20 carbon atoms, a heteroaryl group having 2-20 carbon atoms or a hydrogen atom, provided that Rb1 and Rb2 may be bonded to each other to form a ring together with the carbon atom to which these groups are attached; and n represents an integer of 2 or greater.)

Description

Charge transport varnish

The present invention relates to a charge-transporting varnish.

Organic electroluminescence (hereinafter referred to as "organic EL") devices are expected to be put to practical use in the fields of displays and lighting, and various developments related to materials and device structures are aimed at low voltage drive, high brightness, long life, etc. Has been done.
A plurality of functional thin films are used in this organic EL element, and the hole injection layer, which is one of the functional thin films, transfers charge between the anode and the hole transport layer or the light emitting layer, and is a low layer of the organic EL element. It plays an important role in achieving voltage driving and high brightness.

The method of forming the hole injection layer is roughly classified into a dry process represented by vapor deposition and a wet process represented by spin coating. Comparing these processes, the wet process can efficiently manufacture a thin film having a large area and high flatness.
Therefore, particularly in the field of displays, the wet process is often used not only for forming the hole injection layer but also for forming the upper layers such as the hole transport layer and the light emitting layer (see Patent Document 1). The underlayer such as the hole injection layer is required to have resistance to the solvent used for coating the upper layer.

On the other hand, the coloring of the charge transporting thin film used for the organic EL element deteriorates the color purity and color reproducibility of the organic EL element. Is desired to have high transparency and high transparency (see Patent Document 2).
As described above, as the area of the organic EL display is being increased, the development of the organic EL display using the wet process is being vigorously carried out, and it is excellent in solvent resistance and transparent. There is always a demand for materials for wet processes that give a charge transporting thin film having good properties.

JP, 2008-78181, A International Publication No. 2013/042623

The present invention has been made in view of the above circumstances, and provides a thin film having good solvent resistance, and can realize an organic EL device having good characteristics when the thin film is applied to a hole injection layer or the like. The purpose is to provide a charge transporting varnish.

The present inventor has conducted extensive studies in order to achieve the above-mentioned object, and as a result, a charge-transporting varnish containing a charge-transporting substance and a predetermined polymer compound having an NH group in the molecule thereof has a thin film excellent in solvent resistance. The present invention has been completed by finding that an organic EL device having good characteristics can be obtained when this thin film is applied to a hole injection layer or the like.

That is, the present invention is
1. A charge-transporting varnish comprising a charge-transporting substance, a polymer compound represented by the following formula (I), and an organic solvent:

(In the formula, R ^a1 to R ^a8 each independently have a hydrogen atom, a halogen atom, a nitro group, a hydroxy group, or may have an ether bond, a ketone bond or an ester bond, and have 1 to 20 carbon atoms. It represents an alkyl group, an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ^a4 and R ^a8 are bonded to each other to form a single bond, a methylene group, —O—, or —NR. ^{a d1} -group (R ^d1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms),
R ^b1 represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group,
R ^b2 is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a heteroaryl having 2 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group. Represents a group or a hydrogen atom,
R ^b1 and R ^b2 may be bonded to each other to form a ring together with the carbon atom to which they are bonded,
n represents an integer of 2 or more. )
2. The polymer compound is a charge-transporting varnish represented by the following formula (II):

(In the formula, R ^a1 to R ^a3 , R ^a5 to R ^a7 , R ^b1 , R ^b2 and n have the same meanings as described above.)
3. The polymer compound is a charge-transporting varnish represented by the following formula (III):

(In the formula, R ^a1 to R ^a3 , R ^a5 to R ^a7 and n have the same meanings as described above. R ^c1 to R ^c8 each independently represent a hydrogen atom, a halogen atom, a nitro group, an amino group, Or represents a hydroxy group.)
4. 3. The charge-transporting varnish of 3, wherein R ^a1 to R ^a3 , R ^a5 to R ^a7 and R ^c1 to R ^c8 are hydrogen atoms,
5. The charge-transporting varnish according to any one of 1 to 4, wherein the charge-transporting substance is an aniline derivative,
6. A charge-transporting varnish according to any one of 1 to 5 containing a dopant substance,
7. 6. The charge-transporting varnish according to 6, wherein the dopant substance is an aryl sulfonate compound.
8. A charge-transporting thin film produced by using the charge-transporting varnish according to any one of 1 to 7,
9. 8, an electronic device comprising the charge transporting thin film,
10. 8. An organic electroluminescence device comprising the charge transporting thin film of 8,
11. The organic electroluminescent device according to 10, wherein the charge transporting thin film is a hole injecting layer or a hole transporting layer.

The charge-transporting varnish of the present invention contains a predetermined polymer compound having an NH group in the molecule, and by using this varnish, a charge-transporting thin film excellent in solvent resistance can be obtained. Depending on the type of the charge transporting substance to be used, a charge transporting thin film having excellent transparency and a high refractive index can be obtained.
This charge transporting thin film can be suitably used as a thin film for an electronic device such as an organic EL device, particularly as a thin film for an electronic device in which a thin film is laminated on the upper layer by a wet process.

Hereinafter, the present invention will be described in more detail.
The charge-transporting varnish of the present invention is characterized by containing a charge-transporting substance, a polymer compound represented by the formula (I), and an organic solvent. In addition, in this invention, charge transportability is synonymous with electroconductivity. The charge-transporting varnish may be one having a charge-transporting property by itself, or a solid film obtained therefrom having a charge-transporting property.

In formula (1), R ^a1 to R ^a8 each independently have a hydrogen atom, a halogen atom, a nitro group, a hydroxy group, or an ether bond, a ketone bond or an ester bond, and a carbon number of 1 to It represents an alkyl group having 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ^a4 and R ^a8 are bonded to each other to form a single bond, a methylene group, —O—, or A —NR ^d1 — group (R ^d1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms) may be formed. ..

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The alkyl group having 1 to 20 carbon atoms may be linear, branched or cyclic, and is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl. , N-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl groups and the like, straight-chain or branched-chain alkyl groups having 1 to 20 carbon atoms; cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl , Cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl groups, and other cyclic alkyl groups having 3 to 20 carbon atoms.

Specific examples of the alkenyl group having 2 to 20 carbon atoms include ethenyl, n-1-propenyl, n-2-propenyl, 1-methylethenyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl, n- Examples thereof include a 1-eicosenyl group.

Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4- Examples thereof include phenanthryl and 9-phenanthryl groups.

Among these, R ^a1 to R ^a8 are each a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, or R ^a1 to R a ^a3 and R ^a5 to R ^a7 are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, and R ^a4 and R ^a8 are mutually A bonded single bond is preferable, and a single bond in which R ^a1 to R ^a3 and R ^a5 to R ^a7 are hydrogen atoms and R ^a4 and R ^a8 are bonded to each other is more preferable.
Therefore, the polymer compound represented by formula (I) is preferably represented by formula (II), and more preferably represented by formula (II)-1.

(In the formula, R ^a1 to R ^a3 and R ^a5 to R ^a7 have the same meanings as described above.)

On the other hand, in the formulas (I), (II) and (II)-1, R ^b1 is an aryl having 6 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group. Represents a group or a heteroaryl group having 2 to 20 carbon atoms, and R ^b2 represents an alkyl group having 1 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group, and 6 to 6 carbon atoms. It represents an aryl group having 20 or a heteroaryl group having 2 to 20 carbon atoms, or a hydrogen atom, and R ^b1 and R ^b2 may be bonded to each other to form a ring together with the carbon atom to which they are bonded. ..

Specific examples of the heteroaryl group having 2 to 20 carbon atoms include 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl. , 5-isoxazolyl and other oxygen-containing heteroaryl groups; 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl and other sulfur-containing heteroaryl groups; 2-imidazolyl, 4 -Imidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrazyl, 3-pyrazyl, 5-pyrazyl, 6-pyrazyl, 2-pyrimidyl, 4-pyrimidyl, 5-pyrimidyl, 6-pyrimidyl, 3-pyridazyl , 4-pyridazyl, 5-pyridazyl, 6-pyridazyl, 1,2,3-triazin-4-yl, 1,2,3-triazin-5-yl, 1,2,4-triazin-3-yl, 1 ,2,4-triazin-5-yl, 1,2,4-triazin-6-yl, 1,3,5-triazin-2-yl, 1,2,4,5-tetrazin-3-yl, 1 ,2,3,4-tetrazin-5-yl, 2-quinolinyl, 3-quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl, 7-quinolinyl, 8-quinolinyl, 1-isoquinolinyl, 3-isoquinolinyl, 4 -Isoquinolinyl, 5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl, 8-isoquinolinyl, 2-quinoxanyl, 5-quinoxanyl, 6-quinoxanyl, 2-quinazolinyl, 4-quinazolinyl, 5-quinazolinyl, 6-quinazolinyl, 7-quinazolinyl And nitrogen-containing heteroaryl groups such as 8-quinazolinyl, 3-cinnolinyl, 4-cinnolinyl, 5-cinnolinyl, 6-cinnolinyl, 7-cinnolinyl and 8-cinnolinyl groups.
In addition, examples of the halogen atom, the alkyl group having 1 to 20 carbon atoms, and the aryl group having 6 to 20 carbon atoms include those similar to the atoms and groups exemplified for R ^a1 to R ^a8 above.
Further, the ring structure formed by R ^b1 and R ^b2 being bonded to each other and the carbon atom to which they are bonded is such that the benzene ring therein is substituted with a halogen atom, a nitro group, an amino group or a hydroxy group. And optionally a 9H-fluorene-9,9-diyl group and the like.

Of these, R ^b1 and R ^b2 are each an aryl group having 6 to 20 carbon atoms, or R ^b1 and R ^b2 are bonded to each other to form together with the carbon atom to which they are bonded, benzene therein. A 9H-fluorene-9,9-diyl group whose ring may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group is preferable, and the above 9H-fluorene in which R ^b1 and R ^b2 are bonded to each other. A -9,9-diyl group is more preferred.
Therefore, the polymer compound represented by the formula (I) is more preferably the compound represented by the formula (III), and further preferably the compound represented by the formula (III)-1.

In the repeating unit of the polymer compound represented by each of the above formulas, the bonding position of the bond in the diphenylamino skeleton or the carbazole skeleton is not particularly limited, but both the left and right bonds have a diphenylamino skeleton or a carbazole skeleton. Para position is preferred with respect to NH.

Further, in the above formulas (I), (II), (II)-1, (III) and (III)-1, n represents an integer of 2 or more, preferably 2 to 1000, and preferably 5 to 500. More preferable.
In formulas (III) and (III)-1, R ^c1 to R ^c8 each independently represent a hydrogen atom, a halogen atom, a nitro group, an amino group, or a hydroxy group, but a hydrogen atom is preferable.

The weight average molecular weight Mw of the polymer compound represented by the formula (I) used in the present invention is preferably 600 to 1,000,000, more preferably 600 to 200,000. The weight average molecular weight in the present invention is a polystyrene conversion value by gel permeation chromatography.

Examples of the polymer compound represented by the formula (I) used in the present invention include, but are not limited to, those represented by the following formula.

(In the formula, n represents the same meaning as described above.)

The polymer compound represented by the formula (I) includes a monomer represented by the formula (Ia) and a monomer represented by the formula (Ib), (Ic) or (Id), It can be synthesized by polymerizing by a known method such as an addition condensation reaction (for example, the method described in WO 2010/147155).

(In the formula, R ^a1 to R ^a8 , R ^b1 and R ^b2 have the same meanings as described above.)

X ⁰ to X ⁴ each independently represent a hydrogen atom, a halogen atom or a pseudohalogen group.
Examples of the pseudohalogen group include (fluoro)alkylsulfonyloxy groups and aromatic sulfonyloxy groups. Examples of the halogen atom are the same as above.

R ^{b2 ′} is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a hetero group having 2 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group. And R ^b2″ represents a hydrogen atom. Examples of these halogen atom, alkyl group, aryl group and heteroaryl group include the same ones as described above.

The content ratio of the polymer compound in the charge-transporting varnish of the present invention is not particularly limited as long as it does not affect the charge-transporting property of the obtained thin film, but the solvent resistance and the charge of the obtained thin film are not limited. In consideration of the balance with transportability, the proportion of solids contained in the varnish is preferably 0.1 to 50% by mass, more preferably 1 to 30% by mass, still more preferably 5 to 25% by mass, 10 to 20 mass% is more preferable.
In addition, in this invention, solid content means a component other than a solvent.

The charge-transporting substance contained in the charge-transporting varnish of the present invention can be appropriately selected and used from various charge-transporting substances which are conventionally used in the field of organic EL.
Specific examples thereof include oligoaniline derivatives, N,N'-diarylbenzidine derivatives, aniline derivatives such as N,N,N',N'-tetraarylbenzidine derivatives; oligothiophene derivatives, thienothiophene derivatives, thienobenzothiophene derivatives. Derivatives such as thiophene derivatives; various hole transporting substances such as pyrrole derivatives such as oligopyrrole. Among them, aniline derivatives and thiophene derivatives are preferable, aniline derivatives are more preferable, and charge transport with good transparency and refractive index is preferable. In view of obtaining a thin film having a property, an aniline derivative represented by the following formula (1) or (2) described in WO 2015/050253 is more preferable.

The molecular weight of the charge-transporting substance is not particularly limited, but from the viewpoint of preparing a uniform varnish that gives a thin film having high flatness, 200 to 9000 is preferable, and from the viewpoint of obtaining a thin film having high solvent resistance. , 300 or more is more preferable, 400 or more is more preferable, and from the viewpoint of preparing a uniform varnish that gives a highly flat thin film with high reproducibility, 8000 or less is more preferable, 7,000 or less is still more preferable, and 6000 or less is More preferably, 5000 or less is the most suitable.
From the viewpoint of preventing the charge-transporting substance from separating when it is made into a thin film, it is preferable that the charge-transporting substance does not have a molecular weight distribution (dispersion degree is 1) (that is, a single molecular weight is preferable). ).

In formula (2), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 20 carbon atoms, which may be substituted with a halogen atom, Represents an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, and these halogen atoms and alkyl having 1 to 20 carbon atoms. The group, the alkenyl group having 2 to 20 carbon atoms, the aryl group having 6 to 20 carbon atoms, and the heteroaryl group having 2 to 20 carbon atoms are the same as those exemplified for the polymer compound represented by the above formula (I). The ones are listed.

Specific examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl- 2-propynyl, n-1-pentynyl, n-2-pentynyl, n-3-pentynyl, n-4-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n- Examples include butynyl, 1,1-dimethyl-n-propynyl, n-1-hexynyl, n-1-decynyl, n-1-pentadecynyl, n-1-eicosinyl groups and the like.

Ph ¹ in the above formulas (1) and (2) represents a group represented by the formula (P1).

Here, R ³ to R ⁶ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 20 carbon atoms, which may be substituted with a halogen atom, and a carbon number of 2 Represents an alkenyl group having 20 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, and specific examples thereof are the same as those described above. The ones are listed.
Among these, R ³ to R ⁶ are each a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 20 carbon atoms which may be substituted with a halogen atom, or a carbon number which may be substituted with a halogen atom. An aryl group having 6 to 20 and a heteroaryl group having 2 to 20 carbon atoms which may be substituted with a halogen atom are preferable, and a hydrogen atom, a fluorine atom, a cyano group, or 1 carbon atoms which may be substituted with a halogen atom. The alkyl group of 10 and a phenyl group which may be substituted with a halogen atom are more preferable, a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group are even more preferable, and a hydrogen atom is most preferable.

Specific examples of groups suitable as Ph ^{1 will be} shown below, but the present invention is not limited thereto.

Ar ¹ in the above formula (1) independently represents a group represented by any of the formulas (B1) to (B11), and particularly, in any one of the formulas (B1′) to (B11′). The groups represented are preferred.

Here, R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ may be each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, or a halogen atom, Diphenylamino group, alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms or heteroaryl group having 2 to 20 carbon atoms represents, R ²⁸ and R ²⁹ each independently may be substituted with Z ^1, represents a heteroaryl group an aryl group or a C 2-20 carbon atoms 6 ~ 20, R ⁵² is hydrogen Atom, an alkyl group having 1 to 20 carbon atoms, which may be substituted with Z ⁴ , an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms, or the number of carbon atoms which may be substituted with Z ^1. Represents an aryl group having 6 to 20 or a heteroaryl group having 2 to 20 carbon atoms, Z ¹ is a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 20 carbon atoms, which may be substituted with Z ^2. Group, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, Z ² has 6 to 6 carbon atoms which may be substituted with a halogen atom, a nitro group, a cyano group or Z ^3. 20 represents an aryl group or a heteroaryl group having 2 to 20 carbon atoms, Z ³ represents a halogen atom, a nitro group or a cyano group, and Z ⁴ is substituted with a halogen atom, a nitro group, a cyano group, or Z ⁵ . Represents an optionally substituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, and Z ⁵ may be substituted with a halogen atom, a nitro group, a cyano group, or Z ^3. Represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms. Of these halogen atoms, alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms and heteroaryl groups having 2 to 20 carbon atoms. Specific examples include those similar to the groups described above.

In particular, R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ are each a hydrogen atom, a fluorine atom, a cyano group, a diphenylamino group which may be substituted with a halogen atom, or a halogen atom. Preferred are an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms optionally substituted with a halogen atom, and a heteroaryl group having 2 to 20 carbon atoms optionally substituted with a halogen atom. , A hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, and a phenyl group which may be substituted with a halogen atom are more preferable, and a hydrogen atom, a fluorine atom, methyl More preferred are groups and trifluoromethyl groups, with hydrogen atoms being most preferred.
The R ²⁸ and R ^29, an aryl group Z ¹ ~ carbon atoms 6 optionally substituted with 14, a heteroaryl group Z ¹ ~ 2 carbon atoms which may be substituted with 14 preferably by Z ¹ aryl group optionally substituted 6 carbon atoms even if to 14, more preferably, a phenyl group which may be substituted with Z ^1, which may be substituted with Z ¹ 1-naphthyl group, substituted with Z ¹ Even more preferred is 2-naphthyl group.
As R ^52, a hydrogen atom, an aryl group which may 6 carbon atoms also be ~ 20 substituted with Z ^1, heteroaryl group are optionally 2-20 carbon atoms substituted with Z ^1, substituted by Z ⁴ preferably an alkyl group which may having 1 to 20 carbon atoms have a hydrogen atom, Z ¹ substituted by optionally also a good C 6-14 aryl group, Z ¹ ~ 2 carbon atoms which may be substituted with 14 heteroaryl group, more preferably an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ^4, a hydrogen atom, an aryl group of Z ¹ ~ carbon atoms 6 be replaced by 14, with Z ¹ A nitrogen-containing heteroaryl group having 2 to 14 carbon atoms which may be substituted, and an alkyl group having 1 to 10 carbon atoms which may be substituted by Z ⁴ are more preferable, and a hydrogen atom or Z ¹ may be substituted. A phenyl group, a ¹ -naphthyl group optionally substituted with Z ¹ , a 2-naphthyl group optionally substituted with Z ¹ , a 2-pyridyl group optionally substituted with Z ¹ , and Z ¹ A 3-pyridyl group which may be substituted, a 4-pyridyl group which may be substituted by Z ¹ and a methyl group which may be substituted by Z ⁴ are more preferable.

Ar ^4's each independently represent an aryl group having 6 to 20 carbon atoms which may be substituted with an arylamino group having 6 to 20 carbon atoms.
Specific examples of the aryl group having 6 to 20 carbon atoms include those similar to the groups described above.
Specific examples of the arylamino group having 6 to 20 carbon atoms include diphenylamino group, 1-naphthylphenylamino group, di(1-naphthyl)amino group, 1-naphthyl-2-naphthylamino group, di(2- Naphthyl)amino group and the like.
Among them, Ar ⁴ is phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group. Group, 4-phenanthryl group, 9-phenanthryl group, p-(diphenylamino)phenyl group, p-(1-naphthylphenylamino)phenyl group, p-(di(1-naphthyl)amino)phenyl group, p-( A 1-naphthyl-2-naphthylamino)phenyl group and a p-(di(2-naphthyl)amino)phenyl group are preferable, and a p-(diphenylamino)phenyl group is more preferable.

Specific examples of groups suitable as Ar ¹ are shown below, but the invention is not limited thereto.

(In the formula, R ⁵² has the same meaning as above.)

Ar ² in the above formula (1) each independently represents a group represented by any of the formulas (A1) to (A18).

(In the formula, DPA represents a diphenylamino group, and Ar ⁴ , Z ¹ , and Z ³ to Z ⁵ have the same meanings as described above.)

In formula (A16), R ¹⁵⁵ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z ⁴ . Alternatively, it represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with Z ¹ .
In formula (A17), R ¹⁵⁶ and R ¹⁵⁷ each independently represent an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with Z ¹ .
Of these halogen atoms, alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms and heteroaryl groups having 2 to 20 carbon atoms. Specific examples thereof include the same groups as those described above.

Particularly, as the R ^155, a hydrogen atom, an aryl group of Z ¹ is carbon atoms 6 also be ~ 20 substituted with a heteroaryl group which have 2-20 carbon atoms substituted with Z ^1, with Z ⁴ alkyl group substituted-1 carbon atoms which may be 20, more preferably a hydrogen atom, Z ¹ substituted by optionally 6 carbon atoms which may be ~ 14 aryl group, Z ¹ carbon atoms which may be substituted with 2 More preferably, it is a heteroaryl group having 14 to 14 carbon atoms, an alkyl group having 1 to 10 carbon atoms which may be substituted by Z ⁴ , a hydrogen atom, an aryl group having 6 to 14 carbon atoms which may be substituted by Z ¹ , and Z. even more preferably an alkyl group having a nitrogen-containing heteroaryl group, Z ⁴ carbon atoms which may be substituted with 1 to 10 also 1-2 carbon atoms 14 substituted with ^1, hydrogen atom is substituted with Z ¹ Optionally substituted phenyl group, ¹ -naphthyl group optionally substituted by Z ¹ , 2-naphthyl group optionally substituted by Z ¹ , 2-pyridyl group optionally substituted by Z ¹ , ^A 3-pyridyl group optionally substituted with ¹ , a 4-pyridyl group optionally substituted with Z ¹ , and a methyl group optionally substituted with Z ⁴ are more preferable.
As the R ¹⁵⁶ and R ^157, an aryl group Z ¹ ~ carbon atoms 6 optionally substituted with 14, a heteroaryl group Z ¹ ~ 2 carbon atoms which may be substituted with 14 Preferably, Z more preferably an aryl group which may having 6 to 14 carbon atoms optionally substituted with ^1, a phenyl group which may be substituted with Z ^1, which may be substituted with Z ¹ 1-naphthyl group, substituted with Z ¹ Even more preferred are 2-naphthyl groups which may be present.

Specific examples of groups suitable as Ar ² will be given below, but the present invention is not limited thereto.

(In the formula, R ¹⁵⁵ has the same meaning as above.)

In the formula (1), in view of the ease of synthesis of the resulting aniline derivative, Ar ¹ are all the same group, it is preferable that all of Ar ² are identical groups, Ar ¹ and Ar ² It is more preferable that all are the same groups. That is, the aniline derivative represented by the formula (1) is more preferably the aniline derivative represented by the formula (1-1).
In addition, the aniline represented by the formula (1) can be synthesized relatively easily using a relatively inexpensive bis(4-aminophenyl)amine as a raw material compound and has excellent solubility in an organic solvent. The derivative is preferably an aniline derivative represented by the formula (1-1).

In the formula (1-1), Ph ¹ and k have the same meanings as described above, and Ar ⁵ at the same time represents a group represented by any one of formulas (D1) to (D13). ) To (D13') are preferred, and in particular, since a charge-transporting thin film having high transparency and a high refractive index is obtained, the group represented by the formula (D11) is More preferably, the group represented by formula (D11′-1) is even more preferable.
Specific examples of Ar ⁵ include the same groups as those described above as specific examples of groups suitable as Ar ¹ .

(In the formula, R ²⁸ , R ²⁹ , R ⁵² , Ar ⁴ and DPA have the same meanings as described above.)

In addition, since it can be synthesized relatively easily using a relatively inexpensive bis(4-aminophenyl)amine as a raw material compound, and the solubility of the obtained aniline derivative in an organic solvent is excellent, The aniline derivative represented is preferably the aniline derivative represented by the formula (1-2).

Ar ⁶ at the same time represents a group represented by any one of the formulas (E1) to (E14). Also in this case, a charge-transporting thin film having high transparency and a high refractive index can be obtained. The group represented by (E14) is preferable.

(In the formula, R ⁵² has the same meaning as above.)

Ar ³ in the above formula (2) represents a group represented by any of the formulas (C1) to (C8), and particularly preferably a group represented by any of (C1′) to (C8′). .

K in the above formula (1) represents an integer of 1 to 10, but from the viewpoint of enhancing the solubility of the compound in an organic solvent, 1 to 5 is preferable, 1 to 3 is more preferable, and 1 or 2 is further Preferably, 1 is optimum.
1 in the above formula (2) represents 1 or 2.

In R ²⁸ , R ²⁹ , R ^52, and R ¹⁵⁵ to R ¹⁵⁷ , Z ¹ is a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ² , or Z. is an alkenyl group having 2 to 10 carbon atoms which may have, alkynyl group which 2 carbon atoms which may be ~ 10 substituted with Z ² preferably substituted by ^2, halogen atom, nitro group, cyano group, substituted with Z ² is 1 carbon atoms which may be 1-3 alkyl group, Z ² substituted by 2 carbon atoms which may be 1-3 alkenyl group, an alkynyl group having Z ² ~ 2 carbon atoms which may be substituted with 3 more preferably, a fluorine atom, an alkyl group of Z ² ~ 1 carbon atoms which may be substituted by 3, alkenyl groups of Z ² ~ 2 carbon atoms which may be substituted by 3, optionally substituted by Z ² A good alkynyl group having 2 to 3 carbon atoms is even more preferable.

In R ²⁸ , R ²⁹ , R ⁵² and R ¹⁵⁵ to R ¹⁵⁷ , Z ⁴ is preferably a halogen atom, a nitro group, a cyano group or an aryl group having 6 to 14 carbon atoms which may be substituted with Z ^5. atom, a nitro group, a cyano group, more preferably an aryl group which may having 6 to 10 carbon atoms optionally substituted with Z ^5, a fluorine atom, an aryl group which may 6 carbon atoms also be ~ 10 substituted by Z ⁵ It is even more preferable, and a phenyl group optionally substituted with a fluorine atom or Z ⁵ is even more preferable.

In R ^28, R ^29, R ⁵² and R ¹⁵⁵ ~ R ^157, Z ² is a halogen atom, a nitro group, a cyano group, an aryl group of Z ³ may be substituted having from 6 to 14 carbon atoms preferably, a halogen atom , A nitro group, a cyano group, and an aryl group having 6 to 10 carbon atoms which may be substituted with Z ³ are more preferable, and a fluorine atom and an aryl group having 6 to 10 carbon atoms which may be substituted with Z ³ are more preferable. More preferred is a phenyl group which may be substituted with a fluorine atom or Z ³ , and further preferred.

In R ^28, R ^29, R ⁵² and R ¹⁵⁵ ~ R ^157, Z ⁵ is a halogen atom, a nitro group, a cyano group, an alkyl group which 1 carbon atoms which may be ~ 10 substituted by Z ^3, with Z ³ An alkenyl group having 2 to 10 carbon atoms which may be substituted, and an alkynyl group having 2 to 10 carbon atoms which may be substituted by Z ³ are preferable, and are substituted with a halogen atom, a nitro group, a cyano group or Z ^3. an alkyl group having 1 to 3 carbon atoms may be, more preferably an alkynyl group Z ³ in the optionally substituted alkenyl group having a carbon number of 2 to 3 also, Z ³ ~ 2 carbon atoms which may be substituted with 3 , a fluorine atom, an alkyl group of Z ³ ~ carbon atoms 1 be replaced by 3, an optionally substituted alkenyl group having 2 to 3 carbon atoms in Z ^3, which may be substituted with Z ³ carbon Alkynyl groups of the number 2-3 are even more preferred.

In R ²⁸ , R ²⁹ , R ⁵² and R ¹⁵⁵ to R ¹⁵⁷ , Z ³ is preferably a halogen atom, more preferably a fluorine atom.

On the other hand, in R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ , Z ¹ is a halogen atom, a nitro group, a cyano group or an alkyl group having 1 to 3 carbon atoms which may be substituted with Z ^2. group, an alkenyl group of Z ² ~ 2 carbon atoms which may be substituted with 1-3, an alkynyl group having 2 to 3 carbon atoms are preferable optionally substituted by Z ^2, a halogen atom, optionally substituted by Z ² More preferably, it is an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group optionally substituted with a fluorine atom or Z ² .

In R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ , Z ⁴ is a halogen atom, a nitro group, a cyano group or an aryl group having 6 to 10 carbon atoms which may be substituted with Z ^5. Of these, a halogen atom and an aryl group having 6 to 10 carbon atoms which may be substituted with Z ⁵ are more preferable, and a phenyl group which may be substituted with a fluorine atom and Z ⁵ are even more preferable.

In R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ , Z ² is a halogen atom, a nitro group, a cyano group or an aryl group having 6 to 10 carbon atoms which may be substituted with Z ^3. Of these, a halogen atom and an aryl group having 6 to 10 carbon atoms which may be substituted with Z ³ are more preferable, and a phenyl group which may be substituted with a fluorine atom and Z ³ are even more preferable.

In R ⁷ to R ²⁷ , R ³⁰ to R ^51, and R ⁵³ to R ¹⁵⁴ , Z ⁵ is a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 3 carbon atoms which may be substituted with Z ³ . Z ^{3-substituted} 2 carbon atoms which may be 1-3 alkenyl group is preferably an alkynyl group which may having 2 or 3 carbon atoms optionally substituted by Z ^3, halogen atom, optionally substituted by Z ³ An alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group optionally substituted with a fluorine atom or Z ³ is even more preferable.

In R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ , Z ³ is preferably a halogen atom, more preferably a fluorine atom.

Specific examples of the groups suitable as R ⁵² and R ¹⁵⁵ include the following groups, but are not limited thereto. Among these, the formula (N1) is preferable.

The alkyl group, alkenyl group and alkynyl group preferably have 10 or less carbon atoms, more preferably 6 or less carbon atoms, and even more preferably 4 or less carbon atoms.
The carbon number of the aryl group and the heteroaryl group is preferably 14 or less, more preferably 10 or less, still more preferably 6 or less.

The aniline derivative represented by the formula (1), the formula (1-1), the formula (1-2) and the formula (2) should be produced by the method described in the above-mentioned WO 2015/050253. You can

The charge-transporting varnish of the present invention may contain a dopant substance for the purpose of improving its charge-transporting ability or the like depending on the use of the resulting thin film.
The dopant substance is not particularly limited as long as it is soluble in at least one solvent used for the varnish, and either an inorganic dopant substance or an organic dopant substance can be used.
The inorganic and organic dopant substances may be used alone or in combination of two or more.
Furthermore, the dopant substance exhibits its function as a dopant substance for the first time when, for example, a part of the molecule is removed by an external stimulus such as heating during firing in the process of obtaining a charge transporting thin film that is a solid film from varnish. Alternatively, it may be an improved substance, for example, an aryl sulfonic acid ester compound in which a sulfonic acid group is protected by a group capable of leaving easily.

Particularly, in the present invention, heteropolyacid is preferable as the inorganic dopant substance.
The heteropoly acid has a structure in which a hetero atom is located at the center of the molecule, which is represented by a Keggin type chemical structure represented by the formula (H1) or a Dawson type chemical structure represented by the formula (H2). It is a polyacid formed by condensation of isopoly acid, which is an oxygen acid such as vanadium (V), molybdenum (Mo), and tungsten (W), and an oxygen acid of a different element. Examples of such oxyacids of different elements include oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

Specific examples of the heteropolyacid include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, and phosphorus tungstomolybdic acid, which may be used alone or in combination of two or more kinds. Good. In addition, these heteropolyacids are available as commercial products, or can be synthesized by a known method.
In particular, when one kind of heteropolyacid is used, the one kind of heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, and phosphotungstic acid is most suitable. When two or more heteropolyacids are used, one of the two or more heteropolyacids is preferably phosphotungstic acid or phosphomolybdic acid, more preferably phosphotungstic acid.
Incidentally, the heteropolyacid, in the quantitative analysis such as elemental analysis, those having a large number of elements from the structure represented by the general formula, or those having a small number, those obtained as commercial products, or known synthesis As long as it is appropriately synthesized according to the method, it can be used in the present invention.
That is, for example, generally, phosphotungstic acid is represented by the chemical formula H ₃ (PW ₁₂ O ₄₀ ).nH ₂ O, and phosphomolybdic acid is represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ ).nH ₂ O. , In quantitative analysis, those with a large or small number of P (phosphorus), O (oxygen) or W (tungsten) or Mo (molybdenum) in this formula, or those obtained as commercial products Alternatively, it can be used in the present invention as long as it is appropriately synthesized according to a known synthesis method. In this case, the mass of the heteropolyacid defined in the present invention does not mean the mass of pure phosphotungstic acid in the synthetic product or the commercial product (phosphotungstic acid content), but a commercially available form and a known synthesis. In the form that can be isolated by the method, it means the total mass in the state of containing water of hydration and other impurities.

The amount of the heteropolyacid used can be about 0.001 to 50.0 with respect to the charge transporting substance 1 in terms of mass ratio, preferably about 0.01 to 20.0, more preferably about 0.02. It is about 1 to 10.0.

On the other hand, as the organic dopant substance, a tetracyanoquinodimethane derivative or a benzoquinone derivative can be used.
Specific examples of the tetracyanoquinodimethane derivative include 7,7,8,8-tetracyanoquinodimethane (TCNQ) and halotetracyanoquinodimethane represented by the formula (H3).
Specific examples of the benzoquinone derivative include tetrafluoro-1,4-benzoquinone (F4BQ), tetrachloro-1,4-benzoquinone (chloranil), tetrabromo-1,4-benzoquinone and 2,3-dichloro-5. 6-dicyano-1,4-benzoquinone (DDQ) and the like can be mentioned.

In the formula, R ⁵⁰⁰ to R ⁵⁰³ each independently represent a hydrogen atom or a halogen atom, at least one of which is preferably a halogen atom, at least two of which are halogen atoms, and at least three of which are halogen atoms. It is more preferable that all are halogen atoms.
Examples of the halogen atom include the same ones as described above, but a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable.

Specific examples of such halotetracyanoquinodimethane include 2-fluoro-7,7,8,8-tetracyanoquinodimethane and 2-chloro-7,7,8,8-tetracyanoquinodimethane. 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane, 2,5-dichloro-7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetra Examples include chloro-7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and the like.

The amount of the tetracyanoquinodimethane derivative and the benzoquinone derivative used is preferably 0.0001 to 100 equivalents, more preferably 0.01 to 50 equivalents, still more preferably 1 to 20 equivalents, relative to the charge transporting substance. is there.

The organic dopant substance is an electrically neutral onium comprising a monovalent or divalent anion represented by the following formula (a1) and a counter cation represented by the formulas (c1) to (c5). It is also possible to use borate salts.

(In the formula, each Ar independently represents an aryl group having 6 to 20 carbon atoms which may have a substituent or a heteroaryl group having 2 to 20 carbon atoms which may have a substituent; Represents an alkylene group having 1 to 20 carbon atoms, —NH—, an oxygen atom, a sulfur atom or —CN ⁺ —.)

In formula (a1), the alkylene group having 1 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include methylene, methylmethylene, dimethylmethylene, ethylene, trimethylene and propylene. , Tetramethylene, pentamethylene, hexamethylene groups and the like. In addition, as the aryl group and the heteroaryl group, the same ones as described above can be mentioned.

Suitable examples of the anion of the above formula (a1) include those represented by the formula (a2), but the anion is not limited thereto.

The amount of the onium borate salt used can be about 0.1 to 10 with respect to the charge transporting substance in terms of the substance amount (molar ratio).
The onium borate salt can be synthesized with reference to a known method described in, for example, JP-A-2005-314682.

Further, as the organic dopant substance, an aryl sulfonic acid compound or an aryl sulfonic acid ester compound can also be preferably used.

Specific examples of the arylsulfonic acid compound include benzenesulfonic acid, tosylic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, dihexylbenzene. Sulfonic acid, 2,5-dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7-dibutyl-2-naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3-dodecyl-2-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 4 -Hexyl-1-naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 7-hexyl-1-naphthalenesulfonic acid, 6-hexyl-2-naphthalenesulfonic acid, Dinonylnaphthalene sulfonic acid, 2,7-dinonyl-4-naphthalene sulfonic acid, dinonyl naphthalene disulfonic acid, 2,7-dinonyl-4,5-naphthalene disulfonic acid, 1,4 described in WO 2005/000832. -A benzodioxane disulfonic acid compound, an aryl sulfonic acid compound described in WO 2006/025342, an aryl sulfonic acid compound described in WO 2009/096352, and the like.

Examples of preferable aryl sulfonic acid compounds include aryl sulfonic acid compounds represented by formula (H4) or (H5).

A ¹ represents O or S, and O is preferable.
A ² represents a naphthalene ring or an anthracene ring, but a naphthalene ring is preferable.
A ³ represents a divalent to tetravalent perfluorobiphenyl group, p represents the number of bonds between A ¹ and A ^3, and is an integer satisfying 2≦p≦4, but A ³ is perfluorobiphenyldiyl It is preferably a group, preferably a perfluorobiphenyl-4,4′-diyl group, and p is 2.
q represents the number of sulfonic acid groups bonded to A ² , and is an integer satisfying 1≦q≦4, and 2 is optimal.

A ⁴ to A ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, or a halogenated group having 2 to 20 carbon atoms. It represents an alkenyl group, and at least three of A ⁴ to A ⁸ are halogen atoms.

Examples of the halogenated alkyl group having 1 to 20 carbon atoms include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl , 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4 , 4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, 1,1,2,2,3,3,4,4,4-nonafluorobutyl group, etc. Be done.

Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include perfluorovinyl, perfluoropropenyl (allyl) and perfluorobutenyl groups.
Other examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms include the same ones as described above, but the halogen atom is preferably a fluorine atom.

Among these, A ⁴ to A ⁸ are hydrogen atom, halogen atom, cyano group, alkyl group having 1 to 10 carbon atoms, halogenated alkyl group having 1 to 10 carbon atoms, or alkenyl halide having 2 to 10 carbon atoms. It is preferable that at least three of A ⁴ to A ⁸ are a fluorine atom, and are a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, and an alkyl group having 1 to 5 carbon atoms. More preferably, it is a fluorinated alkyl group or a fluorinated alkenyl group having 2 to 5 carbon atoms, and at least three of A ⁴ to A ⁸ are fluorine atoms, and a hydrogen atom, a fluorine atom, a cyano group, It is even more preferable that it is a perfluoroalkyl group having 1 to 5 carbon atoms or a perfluoroalkenyl group having 1 to 5 carbon atoms, and A ⁴ , A ⁵ and A ⁸ are fluorine atoms.
In addition, the perfluoroalkyl group is a group in which all the hydrogen atoms of the alkyl group are substituted with fluorine atoms, and the perfluoroalkenyl group is a group in which all the hydrogen atoms of the alkenyl group are substituted with fluorine atoms.

R represents the number of sulfonic acid groups bonded to the naphthalene ring, and is an integer satisfying 1≦r≦4, but 2 to 4 is preferable, and 2 is optimal.

The molecular weight of the aryl sulfonic acid compound used as the dopant substance is not particularly limited, but considering the solubility in an organic solvent when used together with the aniline derivative used in the present invention, preferably 2000 or less, more preferably It is 1500 or less.

Specific examples of suitable arylsulfonic acid compounds will be given below, but the invention is not limited thereto.

The amount of the arylsulfonic acid compound used is, in terms of a substance amount (molar ratio), preferably about 0.01 to 20.0, and more preferably about 0.4 to 5.0 with respect to the charge transporting substance 1. ..
As the aryl sulfonic acid compound, a commercially available product may be used, but it can also be synthesized by a known method described in WO 2006/025342, WO 2009/096352 and the like.

On the other hand, as the aryl sulfonic acid ester compound, the aryl sulfonic acid ester compound disclosed in International Publication No. 2017/217455, the aryl sulfonic acid ester compound disclosed in International Publication No. 2017/217457, and Japanese Patent Application No. 2017-243631 are disclosed. Examples thereof include the aryl sulfonate compound described above, and specifically, compounds represented by any of the following formulas (H6) to (H8) are preferable.

(In the formula, m is an integer satisfying 1≦m≦4, but 2 is preferable. n is an integer satisfying 1≦n≦4, but 2 is preferable.)

In formula (H6), A ¹¹ is an m-valent group derived from perfluorobiphenyl.
A ¹² is —O— or —S—, but —O— is preferable.
A ¹³ is a (n+1)-valent group derived from naphthalene or anthracene, but a group derived from naphthalene is preferable.
R ^s1 to R ^s4 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ^s5 is optionally substituted 2 to 20 carbon atoms. Is a monovalent hydrocarbon group.

Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and n-hexyl groups. An alkyl group having 1 to 3 carbon atoms is preferable.
The monovalent hydrocarbon group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include ethyl, n-propyl, isopropyl, n-butyl, isobutyl and t-butyl. And alkyl groups such as groups; aryl groups such as phenyl, naphthyl and phenanthryl groups.

In particular, among R ^s1 to R ^s4 , R ^s1 or R ^s3 is a straight chain alkyl group having 1 to 3 carbon atoms and the rest is a hydrogen atom, or R ^s1 is a straight chain alkyl group having 1 to 3 carbon atoms. And it is preferable that R ^s2 to R ^s4 are hydrogen atoms. In this case, the linear alkyl group having 1 to 3 carbon atoms is preferably a methyl group.
Further, R ^s5 is preferably a linear alkyl group having 2 to 4 carbon atoms or a phenyl group.

In formula (H7), A ¹⁴ is an optionally substituted m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, and the hydrocarbon group is one or more. It is a group obtained by removing m hydrogen atoms from a hydrocarbon compound having 6 to 20 carbon atoms and containing an aromatic ring.
Examples of such a hydrocarbon compound include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, phenanthrene and the like.
The hydrocarbon group may have a part or all of its hydrogen atoms further substituted with a substituent, and as such a substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a nitro atom. Group, cyano group, hydroxy group, amino group, silanol group, thiol group, carboxy group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, ester group, thioester group, amide group, monovalent hydrocarbon group, organo Examples thereof include an oxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group and a sulfo group.
Of these, A ¹⁴ is preferably a group derived from benzene, biphenyl or the like.

A ¹⁵ is —O— or —S—, but —O— is preferred.
A ¹⁶ is a (n+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is (n+1) from the aromatic ring of the aromatic hydrocarbon compound having 6 to 20 carbon atoms. It is a group obtained by removing individual hydrogen atoms.
Examples of such an aromatic carbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene.
Among them, A ¹⁶ is preferably a group derived from naphthalene or anthracene, more preferably a group derived from naphthalene.

R ^s6 and R ^s7 each independently represent a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group, and R ^s8 represents a linear or branched monovalent aliphatic group. It is a hydrocarbon group. However, the total carbon number of R ^s6 , R ^s7 and R ^s8 is 6 or more. The upper limit of the total number of carbon atoms of R ^s6 , R ^s7, and R ^s8 is not particularly limited, but is preferably 20 or less, more preferably 10 or less.
Specific examples of the linear or branched monovalent aliphatic hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-hexyl, n-octyl, Alkyl groups having 1 to 20 carbon atoms such as 2-ethylhexyl and decyl groups; vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, Examples thereof include an alkenyl group having 2 to 20 carbon atoms such as a hexenyl group.
Of these, R ^s6 is preferably a hydrogen atom, and R ^s7 and R ^s8 are each independently preferably an alkyl group having 1 to 6 carbon atoms.

In formula (H8), R ^s9 to R ^s13 each independently represent a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, Alternatively, it is a halogenated alkenyl group having 2 to 10 carbon atoms.
The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, Examples thereof include t-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl and n-decyl groups.

The halogenated alkyl group having 1 to 10 carbon atoms is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of the above alkyl group having 1 to 10 carbon atoms are replaced with halogen atoms. Specific examples include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3 ,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2 , 2,3,3,4,4,4-heptafluorobutyl, 1,1,2,2,3,3,4,4,4-nonafluorobutyl group and the like.

The halogenated alkenyl group having 2 to 10 carbon atoms is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of the alkenyl group having 2 to 10 carbon atoms are replaced with halogen atoms. Specific examples include perfluorovinyl, perfluoro-1-propenyl, perfluoro-2-propenyl, perfluoro-1-butenyl, perfluoro-2-butenyl, perfluoro-3-butenyl groups and the like.

Among these, R ^s9 is preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 10 carbon atoms, a halogenated alkenyl group having 2 to 10 carbon atoms, and a nitro group, a cyano group, or 1 to 4 carbon atoms. The halogenated alkyl group and the alkenyl group having 2 to 4 carbon atoms are more preferable, and the nitro group, the cyano group, the trifluoromethyl group, and the perfluoropropenyl group are even more preferable.
As R ^s10 to R ^s13 , a halogen atom is preferable, and a fluorine atom is more preferable.

A ¹⁷ is —O—, —S— or —NH—, but —O— is preferred.
A ¹⁸ is a (n+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is (n+1) from the aromatic ring of the aromatic hydrocarbon compound having 6 to 20 carbon atoms. It is a group obtained by removing individual hydrogen atoms.
Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene.
Among these, A ¹⁸ is preferably a group derived from naphthalene or anthracene, and more preferably a group derived from naphthalene.

R ^s14 to R ^s17 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms.
Specific examples of the monovalent aliphatic hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n. -Alkyl group having 1 to 20 carbon atoms such as heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl group; vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl Examples thereof include alkenyl groups having 2 to 20 carbon atoms such as 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and hexenyl groups, and the like. Alkyl groups having 1 to 20 carbon atoms are preferable, and those having 1 to 20 carbon atoms are preferable. An alkyl group having 10 carbon atoms is more preferable, and an alkyl group having 1 to 8 carbon atoms is still more preferable.

R ^s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or OR ^s19 . R ^s19 is an ^optionally substituted monovalent hydrocarbon group having 2 to 20 carbon atoms.
^Examples of the linear or branched C 1 to C 20 monovalent aliphatic hydrocarbon group for R ^s18 include the same ones as described above.
When R ^s18 is a monovalent aliphatic hydrocarbon group, R ^s18 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Even more preferable.
^Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms of R ^s19 include the monovalent aliphatic hydrocarbon groups described above other than the methyl group, and aryl groups such as phenyl, naphthyl, and phenanthryl groups.
Among these, R ^s19 is preferably a linear alkyl group having 2 to 4 carbon atoms or a phenyl group.
Examples of the substituent that the above monovalent hydrocarbon group may have include a fluorine atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group and a cyano group.

Specific examples of suitable aryl sulfonic acid ester compounds include, but are not limited to, those shown below.

The amount of the arylsulfonic acid ester compound used is preferably about 0.01 to 20 and more preferably about 0.05 to 10 with respect to the charge transporting substance 1 in terms of a substance amount (molar ratio).

In the present invention, considering production of a charge transporting thin film having excellent transparency and a high refractive index, it is preferable to use an aryl sulfonic acid compound or an aryl sulfonic acid ester compound as a dopant substance, which is soluble in a solvent. In consideration of obtaining a thin film having a smaller extinction coefficient, it is more preferable to use the arylsulfonic acid ester compound.

Further, when the obtained thin film is used as a hole injecting layer of an organic EL device, the above charge transporting varnish is an organic silane compound for the purpose of improving the injection property into the hole transporting layer and improving the life characteristics of the device. May be included. The content thereof is usually about 1 to 30 mass% with respect to the total mass of the charge transporting material and the dopant material.

As the organic solvent used when preparing the charge-transporting varnish, a highly soluble solvent that can satisfactorily dissolve the charge-transporting substance and the dopant substance used as necessary can be used.
Examples of such a highly soluble solvent include cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, N-methylpyrrolidone and 1,3-dimethyl-2-imidazo. Examples thereof include organic solvents such as ridinone and diethylene glycol monomethyl ether, but are not limited thereto. These solvents may be used alone or in combination of two or more, and the amount thereof used may be 5 to 100% by mass based on the whole solvent used for the varnish.
It is preferable that both the charge transporting substance and the dopant substance are completely dissolved in the above solvent.

In addition, the varnish contains a high-viscosity organic solvent having a viscosity of 10 to 200 mPa·s at 25° C., particularly 35 to 150 mPa·s, and a boiling point of 50 to 300° C., particularly 150 to 250° C. under normal pressure (atmospheric pressure). By including at least one kind, it becomes easy to adjust the viscosity of the varnish, and as a result, it becomes possible to adjust the varnish according to the coating method used, which gives a thin film having high flatness with good reproducibility.
Examples of the high-viscosity organic solvent include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, Examples thereof include, but are not limited to, 2,3-butanediol, 1,4-butanediol, propylene glycol and hexylene glycol. These solvents may be used alone or in combination of two or more.
The addition ratio of the high-viscosity organic solvent to the entire solvent used in the varnish is preferably within a range in which solid does not precipitate, and the addition ratio is preferably 5 to 80% by mass as long as solid does not precipitate.

Further, for the purpose of improving the wettability with respect to the substrate, adjusting the surface tension of the solvent, adjusting the polarity, adjusting the boiling point, etc., another solvent is used in an amount of 1 to 90% by mass, preferably 1 to 90% by mass, based on the total amount of the solvent used in the varnish. It is also possible to mix them in a proportion of 1 to 50% by mass.
Examples of such a solvent include propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol. Examples thereof include, but are not limited to, monoethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, and n-hexyl acetate. These solvents may be used alone or in combination of two or more.

Further, when the aniline derivative represented by the above formula (1) or (2) is used as the charge transporting substance, the case where the aniline derivative has a substituent on the nitrogen atom at the 9-position of carbazole, for example, When it does not have an NH structure in the molecule, preferably when it has substituents on all nitrogen atoms, it becomes easy to prepare a varnish using only the low polar solvent shown below.
Specific examples of the low polar solvent include chlorine-based solvents such as chloroform and chlorobenzene; aromatic hydrocarbon solvents such as toluene, xylene, tetralin, cyclohexylbenzene and decylbenzene; 1-octanol, 1-nonanol, 1-decanol and the like. Aliphatic alcoholic solvents such as tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, etc. Solvents: methyl benzoate, ethyl benzoate, butyl benzoate, isoamyl benzoate, dimethyl phthalate, bis(2-ethylhexyl phthalate), dibutyl maleate, diisopropyl malonate, dibutyl oxalate, hexyl acetate, diethylene glycol monoethyl ether Examples thereof include ester solvents such as acetate and diethylene glycol monobutyl ether acetate. These may be used alone or in combination of two or more kinds.

The viscosity of the charge-transporting varnish is appropriately determined depending on the thickness of the thin film to be produced and the solid content concentration, but is usually 1 to 50 mPa·s at 25°C.
The solid content concentration of the charge transporting varnish is appropriately set in consideration of the viscosity and surface tension of the varnish, the thickness of the thin film to be produced, etc., but is usually 0.1 to 10.0 mass. %, and from the viewpoint of improving the coating property of the varnish, it is preferably about 0.5 to 5.0% by mass, more preferably about 1.0 to 3.0% by mass.

The method for preparing the charge-transporting varnish is not particularly limited, but for example, solid components such as the polymer compound of formula (I) and the charge-transporting substance are dissolved in a highly soluble solvent, A method of adding a viscous organic solvent, a method of mixing a high-solubility solvent and a high-viscosity organic solvent, and dissolving the polymer compound of formula (I) or a charge-transporting substance therein, charge transport that can use a low-polarity solvent In the case of a volatile substance or a polymer compound, a method of dissolving a solid content in a low polar solvent may be used.

In particular, when a charge-transporting varnish is prepared, from the viewpoint of obtaining a thin film having higher flatness with good reproducibility, after dissolving the charge-transporting substance, the polymer compound, the dopant substance, etc. in an organic solvent, the sub-micrometer order It is desirable to filter using a filter or the like.

The charge-transporting varnish described above can be easily used to produce a charge-transporting thin film by using the varnish, and thus can be suitably used when producing an electronic element, particularly an organic EL element.
In this case, the charge-transporting thin film can be formed by applying the above-mentioned charge-transporting varnish on a base material and firing it.
The method for applying the varnish is not particularly limited, and examples thereof include a dipping method, a spin coating method, a transfer printing method, a roll coating method, a brush coating method, an inkjet method, a spray method, a slit coating method, and the like. It is preferable to adjust the viscosity and surface tension of the varnish accordingly.

Further, the firing atmosphere of the charge-transporting varnish after coating is not particularly limited, and a thin film having a uniform film-forming surface and a high charge-transporting property can be formed not only in the air atmosphere but also in an inert gas such as nitrogen or vacuum. Although it can be obtained, depending on the type of the dopant substance used, firing the varnish in the atmosphere may provide a thin film having charge transportability with good reproducibility.

Although the firing temperature is appropriately set within the range of about 100 to 260° C. in consideration of the use of the obtained thin film, the degree of charge transporting property imparted to the obtained thin film, the type of solvent and the boiling point, etc. When the obtained thin film is used as a hole injection layer of an organic EL device, it is preferably about 140 to 250° C., more preferably about 145 to 240° C., but represented by the above formula (1) or formula (2). When the aniline derivative is used as the charge transporting substance, a thin film having a good charge transporting property can be obtained even by firing at a low temperature of 200° C. or lower.
It should be noted that the temperature may be changed in two or more steps for the purpose of exhibiting a higher uniform film-forming property or advancing the reaction on the base material during the baking. It suffices to use an appropriate device such as an oven.

The thickness of the charge transporting thin film is not particularly limited, but when used as a hole injecting layer, a hole transporting layer or a hole injecting and transporting layer of an organic EL device, the thickness thereof is usually 3 to 300 nm, preferably 5 nm. ~200 nm. As a method of changing the film thickness, there are methods such as changing the solid content concentration in the varnish and changing the amount of the solution on the substrate at the time of coating.

When the above charge transporting thin film is applied to an organic EL element, the above charge transporting thin film can be provided between a pair of electrodes forming the organic EL element.
Typical configurations of the organic EL element include the following (a) to (f), but the invention is not limited thereto. In the following structure, if necessary, an electron blocking layer or the like may be provided between the light emitting layer and the anode, and a hole blocking layer or the like may be provided between the light emitting layer and the cathode. Further, the hole injecting layer, the hole transporting layer or the hole injecting and transporting layer may also have a function as an electron blocking layer, and the electron injecting layer, the electron transporting layer or the electron injecting and transporting layer may be holes (holes). You may also have the function as a block layer. Further, it is possible to provide an optional functional layer between each layer as required.
(A) Anode/hole injecting layer/hole transporting layer/light emitting layer/electron transporting layer/electron injecting layer/cathode (b) anode/hole injecting layer/hole transporting layer/light emitting layer/electron injecting/transporting layer/ Cathode (c) Anode/hole injecting/transporting layer/light emitting layer/electron transporting layer/electron injecting layer/cathode (d) anode/hole injecting/transporting layer/light emitting layer/electron injecting/transporting layer/cathode (e) anode/positive Hole injection layer/hole transport layer/light emitting layer/cathode (f) Anode/hole injection transport layer/light emitting layer/cathode

The "hole injection layer", "hole transport layer" and "hole injection transport layer" are layers formed between a light emitting layer and an anode, and transport holes from the anode to the light emitting layer. In the case where only one layer of the hole-transporting material is provided between the light-emitting layer and the anode, which has a function, it is a “hole-injecting and transporting layer”, and between the light-emitting layer and the anode, When two or more layers of the hole transporting material are provided, the layer close to the anode is the “hole injecting layer” and the other layers are the “hole transporting layer”. In particular, as the hole injecting (transporting) layer, a thin film that is excellent not only in the hole accepting property from the anode but also in the hole injecting property to the hole transporting (light emitting) layer is used.
"Electron injection layer", "electron transport layer" and "electron injection transport layer" are layers formed between a light emitting layer and a cathode and having a function of transporting electrons from the cathode to the light emitting layer. When only one layer of the electron transporting material is provided between the light emitting layer and the cathode, it is an “electron injecting and transporting layer”, and a layer of the electron transporting material is provided between the light emitting layer and the cathode. When two or more layers are provided, the layer close to the cathode is the “electron injection layer” and the other layers are the “electron transport layer”.
The “light emitting layer” is an organic layer having a light emitting function and includes a host material and a dopant material when a doping system is adopted. At this time, the host material mainly has a function of promoting recombination of electrons and holes and confining excitons in the light-emitting layer, and the dopant material efficiently emits excitons obtained by the recombination. Have a function. In the case of a phosphorescent device, the host material has a function of mainly confining excitons generated by the dopant in the light emitting layer.

A charge-transporting thin film prepared from the charge-transporting varnish of the present invention has a function of being provided between an anode and a light-emitting layer such as a hole injection layer, a hole transport layer, and a hole injection transport layer in an organic EL device. Although it can be used as a film, it is usually suitable for a hole injection layer in which an upper layer is formed by coating because it has excellent solvent resistance as described above.

Examples of the materials and manufacturing method used for manufacturing an EL device using the charge transporting varnish of the present invention include, but are not limited to, the following materials.
An example of a method for manufacturing an OLED element having a hole injection layer made of a thin film obtained from the above charge transporting varnish is as follows. In addition, it is preferable that the electrode is previously subjected to cleaning with alcohol, pure water, or the like, or surface treatment such as UV ozone treatment or oxygen-plasma treatment, to the extent that the electrode is not adversely affected.
A hole injection layer is formed on the anode substrate by the above method using the charge transporting varnish. This is introduced into a vacuum vapor deposition apparatus, and a hole transport layer, a light emitting layer, an electron transport layer/hole block layer, an electron injection layer, and a cathode metal are sequentially deposited. Alternatively, instead of forming the hole transport layer and the light emitting layer by vapor deposition in the method, a hole transport layer forming composition containing the hole transporting polymer and a light emitting layer forming composition containing the light emitting polymer are provided. Are used to form these layers by a wet process. If necessary, an electron blocking layer may be provided between the light emitting layer and the hole transport layer.

Examples of the anode material include a transparent electrode typified by indium tin oxide (ITO) and indium zinc oxide (IZO), a metal typified by aluminum, a metal anode composed of an alloy thereof, or the like. Those subjected to a flattening treatment are preferable. A polythiophene derivative or a polyaniline derivative having a high charge transporting property can also be used.
Note that examples of the other metal forming the metal anode include, but are not limited to, gold, silver, copper, indium, and alloys thereof.

As a material for forming the hole transport layer, (triphenylamine) dimer derivative, [(triphenylamine) dimer] spiro dimer, N,N'-bis(naphthalen-1-yl)-N,N'-bis (Phenyl)-benzidine (α-NPD), 4,4′,4″-Tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), 4,4′,4″-Tris[1 -Triarylamines such as naphthyl(phenyl)amino]triphenylamine (1-TNATA), 5,5"-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2': Examples include oligothiophenes such as 5′,2″-terthiophene (BMA-3T).

As a material for forming the light emitting layer, a metal complex such as an aluminum complex of 8-hydroxyquinoline, a metal complex of 10-hydroxybenzo[h]quinoline, a bisstyrylbenzene derivative, a bisstyrylarylene derivative, (2-hydroxyphenyl)benzo. Low-molecular light emitting materials such as metal complexes of thiazole and silole derivatives; poly(p-phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly(3-alkyl) Examples thereof include, but are not limited to, a system in which a light emitting material and an electron transfer material are mixed with a polymer compound such as thiophene) and polyvinylcarbazole.
When the light emitting layer is formed by vapor deposition, the light emitting layer may be co-deposited with a light emitting dopant, and the light emitting dopant may be a metal complex such as tris(2-phenylpyridine)iridium (III) (Ir(ppy) ₃ ). Examples thereof include, but are not limited to, naphthacene derivatives such as rubrene, quinacridone derivatives, condensed polycyclic aromatic rings such as perylene, and the like.

Examples of the material for forming the electron transport layer/hole blocking layer include, but are not limited to, oxydiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

Materials for forming the electron injection layer include metal oxides such as lithium oxide (Li ₂ O), magnesium oxide (MgO), and alumina (Al ₂ O ₃ ), lithium fluoride (LiF), sodium fluoride (NaF). But not limited thereto.
Examples of cathode materials include, but are not limited to, aluminum, magnesium-silver alloys, aluminum-lithium alloys, and the like.
Examples of the material forming the electron blocking layer include, but are not limited to, tris(phenylpyrazole)iridium and the like.

Examples of the hole transporting polymer include poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(N,N′-bis{p-butylphenyl}-1,4-diaminophenylene )], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N′-bis{p-butylphenyl}-1,1′-biphenylene-4,4-diamine )], poly[(9,9-bis{1′-penten-5′-yl}fluorenyl-2,7-diyl)-co-(N,N′-bis{p-butylphenyl}-1,4 -Diaminophenylene)], poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-endcapped with polysilcisquinoxane, poly[(9,9- Didioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(p-butylphenyl))diphenylamine)] and the like.

Examples of the light emitting polymer include poly(9,9-dialkylfluorene) (PDAF) and other polyfluorene derivatives, poly(2-methoxy-5-(2'-ethylhexoxy)-1,4-phenylenevinylene) (MEH- Examples thereof include polyphenylene vinylene derivatives such as PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

Hereinafter, the present invention will be described more specifically with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. The apparatus used is as follows.
(1) MALDI-TOF-MS: manufactured by Bruker, autoflex III smartbeam
(2) ¹ H-NMR: JNM-ECP300 FT NMR SYSTEM manufactured by JEOL Ltd.
(3) Substrate cleaning: Choshu Sangyo Co., Ltd. substrate cleaning equipment (depressurized plasma method)
(4) Application of varnish: Spin coater MS-A100 manufactured by Mikasa Co., Ltd.
(5) Film thickness measurement: manufactured by Kosaka Laboratory Co., Ltd. Fine shape measuring instrument Surfcoder ET-4000
(6) Fabrication of element: Choshu Sangyo Co., Ltd. Multifunctional evaporation system C-E2L1G1-N
(7) Measurement of current density of device: Multichannel IVL measuring device manufactured by E-HTC Co., Ltd. (8) Measurement of refractive index (n): Multi incident angle spectroscopic ellipsometer VASE manufactured by JA Woollam Japan
(9) Measurement of extinction coefficient (k): Multi incident angle spectroscopic ellipsometer VASE manufactured by JA Woollam Japan

[1] Production of charge transporting substance [Synthesis example 1] Synthesis of aniline derivative A The aniline derivative A was synthesized by the method described in WO 2015/050253 according to the following scheme.
¹ H-NMR (300 MHz, THF-d8) δ [ppm]: 8.08 (d, J=7.7 Hz, 2H), 7.99 (d, J=7.7 Hz, 8H), 7.60- 7.64 (m, 19H), 7.42-7.47 (m, 6H), 7.28-7.36 (m, 19H), 7.09-7.21 (m, 6H), 7. 00 (m, 8H).
MALDI-TOF-MS m/Z found: 1404.68 ([M] ⁺ calcd: 1404.56).

[2] Preparation of charge-transporting varnish 0.178 g of the aniline derivative A obtained in Synthesis Example 1 and an aryl sulfonic acid ester B0.3 of the following formula synthesized according to the method described in WO 2017/217455. To a mixture of 157 g (dopant substance/charge transporting substance=1.0 molar ratio), 3.98 g of triethylene glycol butyl methyl ether, 2.39 g of diisopropyl malonate and 1.59 g of dimethyl phthalate were added and stirred at room temperature. Polymer solution C (Mw2800, dispersity Mw/Mn=1.77) 0 represented by the following formula synthesized by the method of Synthesis Example 4 of WO 2010/147155 in a solution obtained by dissolving After adding 0.084 g (ratio of solid content to 20% by mass), the mixture was filtered with a syringe filter having a pore size of 0.2 μm to obtain a charge-transporting varnish.

[Examples 1-2 to 1-4]
The addition amount of the polymer compound C was 0.037 g (ratio to solid content: 10% by mass), 0.144 g (ratio to solid content: 30% by mass), 0.223 g (ratio to solid content: 40% by mass). ), and a charge-transporting varnish was obtained in the same manner as in Example 1-1, except that the weight of the solvent was adjusted so that the solid content in the varnish was 5% by mass.

[Comparative Example 1-1]
A charge-transporting varnish was obtained in the same manner as in Example 1-1, except that the polymer compound C was not added and the weight of the solvent was adjusted so that the solid content in the varnish was 5% by mass. ..

[3] Production of Thin Film and Evaluation of Physical Properties of Film (1) Optical Properties [Examples 2-1 to 2-4 and Comparative Example 2-1]
The varnishes obtained in Examples 1-1 to 1-4 and Comparative Example 1-1 were applied to a quartz substrate using a spin coater, respectively, and then dried at 120° C. for 1 minute under atmospheric baking. Next, the dried quartz substrate was baked at 200° C. for 15 minutes in the air atmosphere to form a uniform thin film of 50 nm on the quartz substrate.
Using the obtained quartz substrate with a thin film, the refractive index n and the extinction coefficient k at a wavelength of 550 nm were measured. The results are shown in Table 1.

As shown in Table 1, the thin film obtained from the charge-transporting varnish of the present invention has a high refractive index and is obtained from the charge-transporting varnish of Comparative Example 2-1 containing no polymer compound C. It can be seen that the extinction coefficient is lower than that of the thin film.

(2) Solvent resistance [Example 3-1 and Comparative example 3-1]
The varnishes prepared in Example 1-1 and Comparative Example 1-1 were applied on an ITO substrate using a spin coater (500 rpm, 5 seconds→2000 rpm, 20 seconds), respectively, and then dried at 120° C. for 1 minute, and further, The film was baked at 200° C. for 15 minutes to prepare a charge transporting thin film. As the ITO substrate, a 25 mm×25 mm×0.7 t glass substrate in which indium tin oxide (ITO) was patterned on the surface with a film thickness of 50 nm was used, and an O ₂ plasma cleaning device (150 W, 30 W before use) The impurities on the surface were removed by (for 2 seconds).

450 ml of toluene was dropped on each of the charge-transporting thin films prepared above, and then the mixture was allowed to stand for 5 minutes. Then, the solvent was removed by rotating the substrate under conditions of 2000 rpm and 20 seconds, and further dried at 150° C. for 5 minutes to completely remove the solvent.
The residual film rate was calculated from the film thickness before and after coating with toluene. The results are shown in Table 2.

As shown in Table 2, since the charge-transporting thin film produced in Example 3-1 was produced from the varnish containing the polymer compound C, the film loss after applying toluene was small and the solvent resistance was high. It turns out to be excellent. In the thin film produced in Comparative Example 3-1, film roughness of about 5 nm occurred after dropping toluene, but in the thin film of Example 3-1, the film roughness did not occur.

[4] Preparation of Single Layer Element and Evaluation of Characteristics [Example 4-1]
A charge transporting thin film was prepared in the same manner as in Example 3-1. An aluminum thin film was formed on this using a vapor deposition device (vacuum degree 4.0×10 ⁻⁵ Pa) to obtain a single layer element. The vapor deposition was performed under the conditions of a vapor deposition rate of 0.2 nm/sec. The thickness of the aluminum thin film was 80 nm.

[Comparative Example 4-1]
A single-layer element was produced in the same manner as in Example 4-1, except that the charge transporting thin film produced by the same method as in Comparative example 3-1 was used.

The current density at a driving voltage of 5 V was measured for each of the single-layer devices produced above. The results are shown in Table 3.

As shown in Table 3, it can be seen that the thin film prepared from the charge-transporting varnish of the present invention exhibits good charge-transporting property.

Claims

A charge-transporting varnish comprising a charge-transporting substance, a polymer compound represented by the following formula (I), and an organic solvent.

(In the formula, R a1 to R a8 each independently have a hydrogen atom, a halogen atom, a nitro group, a hydroxy group, or may have an ether bond, a ketone bond or an ester bond, and have 1 to 20 carbon atoms. It represents an alkyl group, an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R a4 and R a8 are bonded to each other to form a single bond, a methylene group, —O—, or —NR. a d1 -group (R d1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms),
R b1 represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group,
R b2 is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a heteroaryl having 2 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group, an amino group or a hydroxy group. Represents a group or a hydrogen atom,
R b1 and R b2 may be bonded to each other to form a ring together with the carbon atom to which they are bonded,
n represents an integer of 2 or more. )
The charge transporting varnish according to claim 1, wherein the polymer compound is represented by the following formula (II).

(In the formula, R a1 to R a3 , R a5 to R a7 , R b1 , R b2 and n have the same meanings as described above.)
The charge-transporting varnish according to claim 2, wherein the polymer compound is represented by the following formula (III).

(In the formula, R a1 to R a3 , R a5 to R a7 and n have the same meanings as described above. R c1 to R c8 each independently represent a hydrogen atom, a halogen atom, a nitro group, an amino group, Or represents a hydroxy group.)
The charge-transporting varnish according to claim 3, wherein R a1 to R a3 , R a5 to R a7 and R c1 to R c8 are hydrogen atoms.
The charge-transporting varnish according to any one of claims 1 to 4, wherein the charge-transporting substance is an aniline derivative.
The charge-transporting varnish according to any one of claims 1 to 5, which contains a dopant substance.
The charge-transporting varnish according to claim 6, wherein the dopant substance is an aryl sulfonate compound.
A charge-transporting thin film produced using the charge-transporting varnish according to any one of claims 1 to 7.
An electronic device comprising the charge transporting thin film according to claim 8.
An organic electroluminescent device comprising the charge transporting thin film according to claim 8.
The organic electroluminescent element according to claim 10, wherein the charge transporting thin film is a hole injection layer or a hole transport layer.