JPWO2014148415A1 - Charge transport varnish - Google Patents

Abstract

Charge transport material comprising an oligoaniline derivative represented by formula (1), charge transport material comprising an N, N′-diarylbenzidine derivative represented by formula (2), a charge transport property comprising a dopant and an organic solvent varnish. (Wherein R1 represents hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heteroaryl group, R2 to R7 represent hydrogen, halogen, nitro group, cyano group, amino group, aldehyde group, hydroxyl group, Thiol group, sulfonic acid group, carboxylic acid group, alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, -NHY1, -NY2Y3, -C (O) Y4, -OY5, -SY6, -SO3Y7,- C (O) OY8, -OC (O) Y9, -C (O) NHY10 or -C (O) NY11Y12 group. (Wherein R8 to R15 are hydrogen, alkyl group, alkenyl group or alkynyl group) Ar1 and Ar2 represent a group represented by the formula (3) or (4).

Description

  The present invention relates to a charge transporting varnish, and more specifically, a charge that can provide a thin film that is excellent in transparency and charge transportability and can realize high brightness when applied to an organic electroluminescence (hereinafter referred to as organic EL) device. It relates to transportable varnish.

  The present inventors have already reported that a charge transporting thin film obtained from an organic solvent-based charge transporting varnish using a charge transporting material comprising a low molecular weight oligoaniline compound exhibits excellent electroluminescence device characteristics. (See Patent Document 1). In the charge transporting varnish described in Patent Document 1, the low-molecular oligoaniline compound constituting the charge transporting material has the same repeating unit structure in the molecule, and is colored as the conjugated system is extended. When it is a thin film, it has the property of increasing absorption in the visible region.

  It is known that coloring of the charge transporting thin film decreases the color purity and color reproducibility of the organic EL element. Moreover, this coloring becomes a problem in various full-color technologies for organic EL displays such as a three-color light emission method, a white color method, and a color conversion method, and becomes a significant obstacle in stably producing organic EL elements. As described above, it is desired that the charge transporting thin film of the organic EL element has high transmittance in the visible region and high transparency.

  In view of this point, the present inventors use an oligoaniline compound partially containing a conjugated system composed of a repeating unit structure different from an aniline unit or an oligoaniline compound obtained by partially cutting a conjugated system in a molecule. However, it has already been found that a charge-transporting thin film excellent in transparency with suppressed coloring in the visible region can be obtained (see Patent Document 2), but more transparent for improving the light extraction efficiency and the like. A thin film having high properties has been desired, and the organic EL element provided with the thin film described in Patent Document 2 has room for improvement in terms of element characteristics and life performance.

JP 2002-151272 A International Publication No. 2008/032616 Japanese Patent Laid-Open No. 10-088123

  The present invention has been made in view of such circumstances, and has a high transparency and a high charge transport property, and is a charge transport thin film that can exhibit good device characteristics when applied to an organic EL device. It is an object to provide a charge transporting varnish that imparts.

  As a result of intensive studies in order to achieve the above object, the present inventors have determined that a charge transporting substance comprising a predetermined oligoaniline derivative, a charge transporting substance comprising a predetermined N, N′-diarylbenzidine derivative, and a dopant In addition to finding that a thin film having both high transparency and high charge transportability can be obtained from a charge transporting varnish containing, it has been found that excellent luminance characteristics can be realized when the thin film is applied to an organic EL device, The present invention has been completed. Note that Patent Document 3 discloses an organic EL element using N, N′-diphenylbenzidine as a hole transport material, but a thin film having excellent transparency can be obtained by using the compound. Not disclosed.

（式中、Ｒ¹は、それぞれ独立して、水素原子、Ｚ¹で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基、又はＺ²で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基を表し、
Ｒ²〜Ｒ⁷は、それぞれ独立して、水素原子、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基、カルボン酸基、Ｚ¹で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基、Ｚ²で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基、−ＮＨＹ¹、−ＮＹ²Ｙ³、−Ｃ(Ｏ)Ｙ⁴、−ＯＹ⁵、−ＳＹ⁶、−ＳＯ₃Ｙ⁷、−Ｃ(Ｏ)ＯＹ⁸、−ＯＣ(Ｏ)Ｙ⁹、−Ｃ(Ｏ)ＮＨＹ¹⁰又は−Ｃ(Ｏ)ＮＹ¹¹Ｙ¹²基を表し、
Ｙ¹〜Ｙ¹²は、それぞれ独立して、Ｚ¹で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基、又はＺ²で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基を表し、
Ｚ¹は、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基、カルボン酸基、又はＺ³で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基を表し、
Ｚ²は、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基、カルボン酸基、又はＺ³で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基を表し、
Ｚ³は、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基又はカルボン酸基を表し、
ｎは、２〜２０の整数を表す。）

［式中、Ｒ⁸〜Ｒ¹⁵は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基又は炭素数２〜２０のアルキニル基を表し、
Ａｒ¹及びＡｒ²は、それぞれ独立して、式（３）又は（４）で表される基を表す。

（式中、Ｒ¹⁶〜Ｒ²⁵は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基又は炭素数２〜２０のアルキニル基を表し、
Ｘ¹及びＸ²は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基、炭素数２〜２０のアルキニル基、ジフェニルアミノ基、１−ナフチルフェニルアミノ基、２−ナフチルフェニルアミノ基、ジ（１−ナフチル）アミノ基、ジ（２−ナフチル）アミノ基又は１−ナフチル−２−ナフチルアミノ基を表す。）］
２．１の電荷輸送性ワニスを用いて作製される電荷輸送性薄膜。
３．２の電荷輸送性薄膜を有する電子デバイス。
４．２の電荷輸送性薄膜を有する有機ＥＬ素子。
５．電荷輸送性薄膜が、正孔注入層又は正孔輸送層である４の有機ＥＬ素子。
６．１の電荷輸送性ワニスを基材上に塗布して焼成することを特徴とする電荷輸送性薄膜の製造方法。
７．２の電荷輸送性薄膜を用いることを特徴とする有機ＥＬ素子の製造方法。That is, the present invention provides the following charge transporting varnish.
1. It comprises a charge transporting substance comprising an oligoaniline derivative represented by the formula (1), a charge transporting substance comprising an N, N′-diarylbenzidine derivative represented by the formula (2), a dopant and an organic solvent. Charge transport varnish.

(In the formula, each R ¹ independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms. A group, or 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 ² ;
R ^{2 to} R ⁷ are each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or Z ^1. May be 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, an aryl group having 6 to 20 carbon atoms which may be substituted with Z ² , or 2 carbon atoms. ˜20 heteroaryl groups, —NHY ¹ , —NY ² Y ³ , —C (O) Y ⁴ , —OY ⁵ , —SY ⁶ , —SO ₃ Y ⁷ , —C (O) OY ⁸ , —OC ( O) represents ^{Y 9, -C (O) NHY} 10 or -C (O) NY ¹¹ Y ¹² group,
Y ^{1 to} Y ¹² are each independently 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 ¹ , or Z ² 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 ² ,
Z ¹ is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an aryl group having 6 to 20 carbon atoms that may be substituted with Z ^3. Or represents a C2-C20 heteroaryl group,
Z ² is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an alkyl group having 1 to 20 carbon atoms that may be substituted with Z ³ Represents an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms,
Z ³ represents a halogen atom, nitro group, cyano group, amino group, aldehyde group, hydroxyl group, thiol group, sulfonic acid group or carboxylic acid group,
n represents an integer of 2 to 20. )

[Wherein, R ^{8 to} R ¹⁵ each independently 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,
Ar ¹ and Ar ² each independently represent a group represented by the formula (3) or (4).

(Wherein R ^{16 to} R ²⁵ each independently 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,
X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a diphenylamino group, or 1-naphthylphenyl. It represents an amino group, 2-naphthylphenylamino group, di (1-naphthyl) amino group, di (2-naphthyl) amino group or 1-naphthyl-2-naphthylamino group. ]]
A charge transporting thin film produced using the charge transporting varnish of 2.1.
An electronic device having the charge transporting thin film of 3.2.
An organic EL device having the charge transporting thin film of 4.2.
5). 4. The organic EL device according to 4, wherein the charge transporting thin film is a hole injection layer or a hole transport layer.
A method for producing a charge-transporting thin film, comprising applying the charge-transporting varnish of 6.1 onto a substrate and baking.
A method for producing an organic EL device, comprising using the charge transporting thin film of 7.2.

  By using the charge transporting varnish of the present invention, a highly transparent charge transporting thin film with suppressed absorption in the visible region can be obtained. By using this thin film, it is possible to ensure the color reproducibility of the element without degrading the color purity of the electroluminescent light or the light transmitted through the color filter. This can greatly contribute to the improvement of efficiency, and it is possible to reduce the size of the organic EL element and reduce the driving voltage.

  Moreover, by using the charge transporting varnish of the present invention, a charge transporting thin film having high transparency and conductivity can be obtained, and by applying this thin film to a hole injection layer of an organic EL element in particular, An organic EL element having excellent luminance characteristics can be obtained.

  Furthermore, the thin film obtained from the charge transport varnish of the present invention can be used as an antistatic film, an anode buffer layer of an organic thin film solar cell, or the like.

[Charge transporting material consisting of oligoaniline derivative]
The charge transporting varnish of the present invention contains a charge transporting material composed of an oligoaniline derivative represented by the formula (1). Here, the charge transportability is synonymous with conductivity and is synonymous with hole transportability. The charge transporting substance itself may be charge transporting, or may be charge transporting when used with an electron accepting substance. The charge transporting varnish may itself have a charge transporting property, and the resulting solid film may have a charge transporting property.

R ^{1 s} are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, or Z ² 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 ² ;

  The alkyl group having 1 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, C1-C20 straight chain such as s-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group Or a branched alkyl group; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicycloheptyl group, bicyclo C3-C20 cyclic alkyl groups, such as an octyl group, a bicyclononyl group, a bicyclodecyl group, are mentioned.

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

  Specific examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl group, n-1-propynyl group, n-2-propynyl group, n-1-butynyl group, n-2-butynyl group, and n-3-butynyl. Group, 1-methyl-2-propynyl group, n-1-pentynyl group, n-2-pentynyl group, n-3-pentynyl group, n-4-pentynyl group, 1-methyl-n-butynyl group, 2- Methyl-n-butynyl group, 3-methyl-n-butynyl group, 1,1-dimethyl-n-propynyl group, n-1-hexynyl, n-1-decynyl group, n-1-pentadecynyl group, n-1 -Eicosinyl group etc. are mentioned.

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

  Specific examples of the heteroaryl group having 2 to 20 carbon atoms include 2-thienyl group, 3-thienyl group, 2-furanyl group, 3-furanyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 3-isoxazolyl group, 4-isoxazolyl group, 5-isoxazolyl group, 2-thiazolyl, 4-thiazolyl group, 5-thiazolyl group, 3-isothiazolyl group, 4-isothiazolyl group, 5-isothiazolyl group, 2-imidazolyl group, 4 -Imidazolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, etc. are mentioned.

Among these, R ¹ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms that may be substituted with Z ¹ , or an aryl group having 6 to 20 carbon atoms that may be substituted with Z ^2. Preferably, it is more preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or an aryl group having 6 to 14 carbon atoms which may be substituted with Z ² . The alkyl group having 1 to 4 carbon atoms which may be substituted with Z ¹ or the phenyl group which may be substituted with Z ² is more preferable, and a hydrogen atom is most preferable. A plurality of R ¹ may be the same or different.

R ^{2 to} R ⁷ are each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or Z ^1. May be 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, an aryl group having 6 to 20 carbon atoms which may be substituted with Z ² , or 2 carbon atoms. ˜20 heteroaryl groups, —NHY ¹ , —NY ² Y ³ , —C (O) Y ⁴ , —OY ⁵ , —SY ⁶ , —SO ₃ Y ⁷ , —C (O) OY ⁸ , —OC ( O) Y ⁹ , —C (O) NHY ¹⁰ or —C (O) NY ¹¹ Y ¹² group.

Y ^{1 to} Y ¹² are each independently 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 ¹ , or Z ² 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 ² ;

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group represented by R ^{2 to} R ⁷ and Y ^{1 to} Y ¹² are the same as those exemplified as R ¹ .

Of these, R ² to R ⁵ is a hydrogen atom, a halogen atom, Z ¹ is from 1 to 10 carbon atoms which may have alkyl group or Z ² which may be the number 6-14 carbon substituted with substituted with It is preferably an aryl group, more preferably a hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , and even more preferably a hydrogen atom or a halogen atom. It is optimal that all are hydrogen atoms.

R ⁶ and R ⁷ are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms that may be substituted with Z ¹ , or an aryl group having 6 to 14 carbon atoms that may be substituted with Z ^2. Or a diphenylamino group optionally substituted by Z ² (Y ² and Y ³ are a phenyl group optionally substituted by Z ² —NY ² Y ³ group), preferably a hydrogen atom, halogen It is more preferably an atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or a diphenylamino group which may be substituted with Z ² , and may be substituted with a hydrogen atom or Z ² A good diphenylamino group is even more preferable, and a hydrogen atom or a diphenylamino group is still more preferable. In particular, it is optimal that R ⁶ and R ⁷ are both hydrogen atoms or diphenylamino groups.

  In the formula (1), n represents an integer of 2 to 20, and is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less, from the viewpoint of enhancing the solubility of the oligoaniline derivative. From the viewpoint of enhancing the charge transport property of the thin film, it is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more.

The alkyl groups, alkenyl groups, and alkynyl groups of R ^{1 to} R ⁷ and Y ^{1 to} Y ¹² are halogen atoms, nitro groups, cyano groups, amino groups, aldehyde groups, hydroxyl groups, thiol groups, sulfonic acid groups, carboxylic acids. R ^{1 to} R ⁷ and Y ¹ which may be substituted with a group or Z ¹ which is 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 ^3. aryl and heteroaryl groups to Y ¹² is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or may be substituted with Z ³ alkyl group having 1 to 20 carbon atoms, may be substituted with Z ² is an alkenyl group or an alkynyl group having 2 to 20 carbon atoms having 2 to 20 carbon atoms, these radicals may be further halogen atoms, nitro Group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group or may be substituted with Z ³ is a carboxylic acid group (the halogen atom include the same as above.) .

In particular, in R ^{1 to} R ⁷ and Y ^{1 to} Y ¹² , Z ¹ is preferably a halogen atom or an aryl group having 6 to 20 carbon atoms which may be substituted with Z ³ , and is preferably a halogen atom or Z ^3. More preferably, it is a phenyl group which may be substituted with, and most preferably it is not present (that is, unsubstituted).
Z ² is a halogen atom or preferably substituted with Z ³ is an alkyl group which may having 1 to 20 carbon atoms, a halogen atom or Z ³ optionally substituted by an alkyl group having 1 to 4 carbon atoms More preferably, it is optimal that it is not present (ie, unsubstituted).
Z ³ is preferably a halogen atom, more preferably fluorine, and most preferably not present (that is, unsubstituted).

The carbon number of the alkyl group, alkenyl group and alkynyl group represented by R ^{1 to} R ⁷ and Y ^{1 to} Y ¹² is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less. is there. The carbon number of the aryl group and heteroaryl group is preferably 14 or less, more preferably 10 or less, and even more preferably 6 or less.

[Charge transporting substance comprising N, N′-diarylbenzidine derivative]
The charge transporting varnish of the present invention includes a charge transporting material composed of an N, N′-diarylbenzidine derivative represented by the formula (2).

R ^{8 to} R ¹⁵ each independently represent 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. Examples of these alkyl group, alkenyl group and alkynyl group include the same groups as those exemplified as R ¹ .

Among these, R ^{8 to} R ¹⁵ are preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, a hydrogen atom or a carbon atom. The alkyl group is more preferably a 1 to 6 alkyl group, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and most preferably all hydrogen atoms.

In Formula (1), Ar ¹ and Ar ² each independently represent a group represented by Formula (3) or (4).

In the formulas (3) and (4), R ^{16 to} R ²⁵ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl having 2 to 20 carbon atoms. Represents a group. Among these, R ^{16 to} R ²⁵ are preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, a hydrogen atom or a carbon atom. The alkyl group is more preferably a 1 to 6 alkyl group, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and most preferably all hydrogen atoms.

X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a diphenylamino group, or 1-naphthylphenyl. It represents an amino group, 2-naphthylphenylamino group, di (1-naphthyl) amino group, di (2-naphthyl) amino group or 1-naphthyl-2-naphthylamino group. Among these, X ¹ and X ² are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a diphenylamino group, a 1-naphthylphenylamino group, a 2-naphthylphenylamino group, a di (1-naphthyl) amino group, A di (2-naphthyl) amino group or a 1-naphthyl-2-naphthylamino group is preferable, and a hydrogen atom, diphenylamino group, 1-naphthylphenylamino group, 2-naphthylphenylamino group, di (1-naphthyl) is preferable. ) An amino group, a di (2-naphthyl) amino group or a 1-naphthyl-2-naphthylamino group is more preferable, a hydrogen atom or a diphenylamino group is still more preferable, and all are hydrogen atoms. Is optimal.

In addition, the carbon number of the alkyl group, alkenyl group, and alkynyl group represented by R ^{8 to} R ²⁵ , X ^1, and X ² is preferably 10 or less, more preferably 6 or less, and even more preferably 4 It is as follows.

  The molecular weight of the oligoaniline derivative and N, N′-diarylbenzidine derivative used in the present invention is usually 200 to 5,000, but preferably from 3,000 or less, more preferably from the viewpoint of enhancing the solubility of these derivatives. 2,000 or less.

  In the present invention, as the oligoaniline derivative, a commercially available product may be used, or one synthesized by a known method may be used. The synthesis method is not particularly limited. For example, Bulletin of Chemical Society of Japan (1994, Vol. 67, pp. 1749-1752), Synthetic Metals (Synthetic Metals). Metals) (1997, 84, pp. 119-120), International Publication No. 2008/032617, International Publication No. 2008-032616, International Publication No. 2008-129947, and the like.

  On the other hand, the N, N′-diarylbenzidine derivative may be a commercially available product, and a known method (for example, the method described in Thin Solid Films, 520 (24), pp. 7157-7163 (2012)) or Although what was synthesize | combined by the method may be used, before preparing a charge transportable varnish in any case, it is preferable to use what was refine | purified by recrystallization, a vapor deposition method, etc. By using the purified one, the characteristics of the organic EL device provided with the thin film obtained from the varnish can be further enhanced.

  When purifying by recrystallization, for example, 1,4-dioxane, tetrahydrofuran or the like can be used as the solvent.

  The N, N′-diarylbenzidine derivative represented by the formula (2) is obtained, for example, by reacting a biphenyl compound represented by the formula (5) with an aromatic amine compound represented by the formula (6). be able to.

（式中、Ｒ⁸〜Ｒ¹⁵は上記と同じ。Ａｒ³は上記Ａｒ¹及びＡｒ²と同じ。Ｙは、塩素原子、臭素原子、ヨウ素原子等のハロゲン原子を表す。）

(In the formula, R ^{8 to} R ¹⁵ are the same as above. Ar ³ is the same as Ar ¹ and Ar ² above. Y represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom.)

  Examples of the biphenyl compound represented by the formula (5) include 4,4′-dichlorobiphenyl, 4,4′-dibromobiphenyl, 4,4′-diiodobiphenyl, 4-chloro-4′-bromobiphenyl, 4- Examples include chloro-4′-iodobiphenyl and 4-bromo-4′-iodobiphenyl.

  Examples of the aromatic amine compound represented by the formula (6) include aniline, 1-naphthylamine, 4- (diphenylamino) aniline, 4-diphenylamino-1-naphthylamine and the like.

  The charging ratio of the biphenyl compound represented by the formula (5) and the aromatic amine compound represented by the formula (6) should be about 1.8 to 4.0 mol of the aromatic amine compound with respect to 1 mol of the biphenyl compound. However, about 2.0 to 3.0 mol is preferable.

Examples of the catalyst used in the above reaction include copper catalysts such as copper chloride, copper bromide, copper iodide, Pd (PPh ₃ ) ₄ (tetrakis (triphenylphosphine) palladium), Pd (PPh ₃ ) ₂ Cl _2. (Bis (triphenylphosphine) dichloropalladium), Pd (dba) ₂ (bis (benzylideneacetone) palladium), Pd ₂ (dba) ₃ (tris (benzylideneacetone) dipalladium), Pd (Pt-Bu ₃ ) ₂ Palladium catalyst such as (bis (tri (t-butylphosphine) palladium)). These catalysts may be used alone or in combination of two or more. These catalysts may also be used with an appropriate ligand.

  Although the usage-amount of a catalyst can be about 0.001-0.5 mol with respect to 1 mol of biphenyl compounds, about 0.01-0.2 mol is suitable.

  The above reaction may be performed in a solvent. When using a solvent, any solvent may be used as long as it does not adversely affect the reaction. Specific examples of the solvent include aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), halogenated aliphatic hydrocarbons (chloroform, dichloromethane, dichloroethane, carbon tetrachloride, etc.) , Aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.), halogenated aromatic hydrocarbons (chlorobenzene, bromobenzene, o-dichlorobenzene, m-di) Chlorobenzene, p-dichlorobenzene, etc.), ethers (diethyl ether, diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.), ketones (acetone, Methyl ethyl ketone, methyl isobutyl ketone Di-n-butyl ketone, cyclohexanone, etc.), amides (N, N-dimethylformamide, N, N-dimethylacetamide, etc.), lactams and lactones (N-methylpyrrolidone, γ-butyrolactone, etc.), ureas (N, N-dimethylimidazolidinone, tetramethylurea, etc.), sulfoxides (dimethylsulfoxide, sulfolane, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.) and the like. These solvents may be used alone or in combination of two or more.

The reaction temperature may be appropriately set within the range from the melting point to the boiling point of the solvent to be used, but is preferably about 0 to 200 ° C and more preferably 20 to 150 ° C.
After completion of the reaction, the desired N, N′-diarylbenzidine derivative can be obtained by post-treatment according to a conventional method.

Examples of oligoaniline derivatives that can be suitably used in the present invention include, but are not limited to, the following.

Examples of N, N′-diarylbenzidine derivatives that can be suitably used in the present invention include, but are not limited to, the following.

[Dopant]
The charge transporting varnish of the present invention contains a dopant. The dopant is not particularly limited as long as it is soluble in at least one solvent used for the varnish, and any of an inorganic dopant and an organic dopant can be used.

As inorganic dopants, inorganic acids such as hydrogen chloride, sulfuric acid, nitric acid, phosphoric acid; aluminum chloride (III) (AlCl ₃ ), titanium tetrachloride (IV) (TiCl ₄ ), boron tribromide (BBr ₃ ) Boron trifluoride ether complex (BF ₃ · OEt ₂ ), iron (III) chloride (FeCl ₃ ), copper (II) chloride (CuCl ₂ ), antimony pentachloride (V) (SbCl ₅ ), antimony pentafluoride Metal halides such as (V) (SbF ₅ ), arsenic pentafluoride (V) (AsF ₅ ), phosphorus pentafluoride (PF ₅ ), tris (4-bromophenyl) aluminum hexachloroantimonate (TBPAH); Cl ₂ , halogens such as Br ₂ , I ₂ , ICl, ICl ₃ , IBr and IF ₄ ; and heteropolyacids such as phosphomolybdic acid and phosphotungstic acid.

  Examples of organic dopants include benzenesulfonic acid, tosylic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, dihexylbenzenesulfonic 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, dinonyl Phthalenesulfonic acid, 2,7-dinonyl-4-naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, 2,7-dinonyl-4,5-naphthalenedisulfonic acid, 1 described in International Publication No. 2005/000832 , 4-Benzodioxane disulfonic acid compounds, aryl sulfonic acid compounds described in WO 2006/025342, aryl sulfonic acid compounds described in WO 2009/096352, aryl sulfones such as polystyrene sulfonic acid Compound; Non-aryl sulfone compound such as 10-camphorsulfonic acid; 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) ) And the like. These inorganic and organic dopants may be used alone or in combination of two or more.

  Of these, aryl sulfonic acid compounds are preferred, and aryl sulfonic acid compounds represented by formula (7) are more preferred.

（式中、Ｍは酸素原子を表し、Ａはナフタレン環又はアントラセン環を表し、Ｂは２〜４価のパーフルオロビフェニル基を表し、ｐはＡに結合するスルホン酸基数を表し、１≦ｐ≦４を満たす整数であり、ｑはＢとＭとの結合数を表し、２〜４を満たす整数である。）

(In the formula, M represents an oxygen atom, A represents a naphthalene ring or an anthracene ring, B represents a divalent to tetravalent perfluorobiphenyl group, p represents the number of sulfonic acid groups bonded to A, and 1 ≦ p. ≦ 4 is an integer satisfying ≦ 4, q represents the number of bonds between B and M, and is an integer satisfying 2 to 4.)

Although the following are mentioned as a dopant which can be used suitably by this invention, It is not limited to this.

In the present invention, the N, N′-diarylbenzidine derivative represented by the formula (2) is 0.01% with respect to the oligoaniline derivative 1 represented by the formula (1) in a mass ratio (mol ratio). The charge transporting thin film that gives high luminance when used in an organic EL device is preferably set to about 0.1 to 30, more preferably about 0.8 to 20. It can be obtained with good reproducibility. That is, the charge transporting varnish of the present invention has a substance amount of N, N′-diarylbenzidine derivative represented by formula (2) with respect to the substance amount (M _H1 ) of the oligoaniline derivative represented by formula (1) ( The ratio of M _H2 ) satisfies 0.01 ≦ M _H2 / M _H1 ≦ 100, preferably 0.1 ≦ M _H2 / M _H1 ≦ 30, more preferably 0.8 ≦ M _H2 / M _H1 ≦ 20.

In the present invention, a dopant, preferably an aryl sulfonic acid compound, more preferably an aryl sulfonic acid compound represented by formula (7), and still more preferably an aryl sulfonic acid compound represented by formula (8), In terms of substance amount ratio (mol ratio), it refers to a charge transporting substance (an oligoaniline derivative represented by the formula (1) and an N, N′-diarylbenzidine derivative represented by the formula (2). ) Although it can be about 0.01 to 100 with respect to 1, it is preferably about 0.1 to 10, more preferably about 0.3 to 5 so that it is high when used for an organic EL device. A charge transporting thin film that provides brightness can be obtained with good reproducibility. That is, in the charge transporting varnish of the present invention, the ratio of the dopant material amount (M _D ) to the charge transport material amount (M _H ) is 0.01 ≦ M _D / M _H ≦ 100, preferably 0. 0.1 ≦ M _D / M _H ≦ 10, more preferably 0.3 ≦ M _D / M _H ≦ 5.

  In addition to the oligoaniline derivative and N, N′-diarylbenzidine derivative described above, other known charge transport materials can be used for the charge transport varnish of the present invention.

[Organic solvent]
As the organic solvent used in preparing the charge transporting varnish of the present invention, a highly soluble solvent capable of dissolving the charge transporting substance and the dopant satisfactorily can be used. Examples of such highly soluble solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, diethylene glycol monomethyl ether, and the like. . These solvents can be used alone or in combination of two or more, and the amount used can be 5 to 100% by mass with respect to the total solvent used in the varnish. The charge transporting substance and the dopant are preferably either completely dissolved or uniformly dispersed in the solvent, and more preferably completely dissolved.

  The charge transporting varnish of the present invention has a viscosity of 10 to 200 mPa · s, particularly 35 to 150 mPa · s at 25 ° C., and a boiling point of 50 to 300 ° C., particularly 150 to 250 ° C. at normal pressure (atmospheric pressure). These high-viscosity organic solvents may be included. This makes it easy to adjust the viscosity of the varnish. As a result, it is possible to prepare a varnish according to the coating method to be used, which gives a highly flat thin film 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, 2, Examples include, but are not limited to, 3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol, and the like. 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 of the present invention is preferably in the range where no solid precipitates, and the addition ratio is preferably 5 to 80% by mass as long as no solid precipitates.

  Furthermore, 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., 1 to 90% by mass, preferably 1 with respect to the entire solvent used for the varnish. It can also be mixed at a ratio of ˜50 mass%.

  Examples of other solvents include 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, propylene glycol monomethyl ether acetate, diethylene glycol monoacetate. Examples include, but are not limited to, ethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, n-hexyl acetate and the like. These solvents can be used alone or in combination of two or more.

  The viscosity of the varnish of the present invention is appropriately set according to the thickness of the thin film to be produced, the solid content concentration, and the like, but is usually 1 to 50 mPa · s at 25 ° C.

  Further, the solid content concentration of the charge transporting varnish in the present invention 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 usually 0.1 to 10 In consideration of improving the coatability of the varnish, it is preferably 0.5 to 5.0% by mass, more preferably 1.0 to 3.0% by mass.

[Charge transport thin film]
A charge transporting thin film can be formed on a base material by applying the charge transporting varnish of the present invention on the base material and baking 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, an ink jet method, and a spray method. It is preferable to adjust the viscosity and the surface tension.

  Further, when the varnish of the present invention is used, the firing atmosphere is not particularly limited, and a thin film having a uniform film formation surface and a high charge transport property not only in the air atmosphere but also in an inert gas such as nitrogen or in a vacuum. It is possible to obtain.

  The firing temperature is appropriately set within a range of about 100 to 260 ° C. in consideration of the use of the obtained thin film, the degree of charge transportability imparted to the obtained thin film, and the like. When used as a hole injection layer of an EL element, about 140 to 250 ° C is preferable, and about 145 to 240 ° C is more preferable. In firing, two or more steps of temperature change may be applied for the purpose of expressing higher uniform film forming property or allowing the reaction to proceed on the substrate. Heating may be performed using an appropriate device such as a hot plate or an oven.

  The thickness of the charge transporting thin film is not particularly limited, but is preferably 5 to 200 nm when used as a hole injection layer in an organic EL device. 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 during coating.

[Organic EL device]
Examples of materials and methods for producing an OLED element using the charge transporting varnish of the present invention include, but are not limited to, the following.

  The electrode substrate to be used is preferably cleaned in advance by cleaning with a liquid such as a detergent, alcohol, or pure water. For example, the anode substrate is subjected to surface treatment such as UV ozone treatment or oxygen-plasma treatment immediately before use. It is preferable. However, when the anode material contains an organic material as a main component, the surface treatment may not be performed.

  The example of the manufacturing method of the OLED element which has a positive hole injection layer which consists of a thin film obtained from the charge transportable varnish of this invention is as follows.

  By the above method, the charge transporting varnish of the present invention is applied onto the anode substrate and baked to produce a hole injection layer on the electrode. This is introduced into a vacuum deposition apparatus, and a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode metal are sequentially deposited to form an OLED element. In order to control the light emitting region, a carrier block layer may be provided between arbitrary layers.

  Examples of the anode material include transparent electrodes typified by indium tin oxide (ITO) and indium zinc oxide (IZO), and those subjected to planarization treatment are preferable. Polythiophene derivatives and polyaniline derivatives having high charge transporting properties can also be used.

  As a material for forming the hole transport layer, (triphenylamine) dimer derivative (TPD), N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (α-NPD), [(tri Phenylamine) dimer] triarylamines such as spiro-dimer (Spiro-TAD), 4,4 ′, 4 ″ -tris [3-methylphenyl (phenyl) amino] triphenylamine (m-MTDATA), 4, Starburst amines such as 4 ′, 4 ″ -tris [1-naphthyl (phenyl) amino] triphenylamine (1-TNATA), 5,5 ″ -bis- {4- [bis (4-methylphenyl) ) Amino] phenyl} -2,2 ′: 5 ′, 2 ″ -terthiophene (BMA-3T) and other oligothiophenes.

As a material for forming the light emitting layer, tris (8-quinolinolato) aluminum (III) (Alq ₃ ), bis (8-quinolinolato) zinc (II) (Znq ₂ ), bis (2-methyl-8-quinolinolato) ( p-phenylphenolate) aluminum (III) (BAlq) and 4,4′-bis (2,2-diphenylvinyl) biphenyl (DPVBi), and the like. The light emitting layer may be formed by co-evaporation.

As an electron transport material, Alq ₃ , BAlq, DPVBi, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (PBD), triazole derivative (TAZ) , Bathocuproine (BCP), silole derivatives and the like.

As the luminescent dopant, quinacridone, rubrene, coumarin 540, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), tris (2-phenylpyridine) iridium ( III) (Ir (ppy) ₃ ), (1,10-phenanthroline) -tris (4,4,4-trifluoro-1- (2-thienyl) -butane-1,3-dionate) europium (III) ( Eu (TTA) ₃ phen) and the like.

  Examples of the material for forming the carrier block layer include PBD, TAZ, and BCP.

Materials for forming the electron injection layer include lithium oxide (Li ₂ O), magnesium oxide (MgO), alumina (Al ₂ O ₃ ), lithium fluoride (LiF), sodium fluoride (NaF), magnesium fluoride ( MgF ₂ ), strontium fluoride (SrF ₂ ), Liq, Li (acac), lithium acetate, lithium benzoate and the like.

  Examples of the cathode material include aluminum, magnesium-silver alloy, aluminum-lithium alloy, lithium, sodium, potassium, cesium and the like.

  Although the manufacturing method of the PLED element using the charge transportable varnish of this invention is not specifically limited, The following methods are mentioned.

  In the preparation of the OLED element, instead of performing the vacuum deposition operation of the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the hole transport polymer layer and the light emitting polymer layer are sequentially formed. A PLED element having a charge transporting thin film formed by the charge transporting varnish of the invention can be produced. Specifically, the charge transporting varnish of the present invention is applied on the anode substrate to prepare a hole injection layer by the above method, and a hole transporting polymer layer and a light emitting polymer layer are sequentially formed thereon. Then, a cathode electrode is vapor-deposited to obtain a PLED element.

  As the cathode and anode material to be used, the same materials as those used in the production of the OLED element can be used, and the same cleaning treatment and surface treatment can be performed.

  As a method for forming the hole transporting polymer layer and the light emitting polymer layer, a hole transporting polymer material or a light emitting polymer material, or a material in which a dopant is added to these materials are added and dissolved, The method of forming into a film by disperse | distributing uniformly and apply | coating on a positive hole injection layer or a positive hole transportable polymer layer, and baking each is mentioned.

  As the hole transporting polymer material, 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 polish Rusesquioxane, poly [(9,9-didioctylfluoreni -2,7-diyl) -co- (4,4 ′-(N- (p-butylphenyl)) diphenylamine)] and the like.

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

  Examples of the solvent include toluene, xylene, chloroform and the like. Examples of the dissolution or uniform dispersion method include methods such as stirring, heating and stirring, and ultrasonic dispersion.

  The application method is not particularly limited, and examples thereof include an inkjet method, a spray method, a dipping method, a spin coating method, a transfer printing method, a roll coating method, and a brush coating method. The application is preferably performed under an inert gas such as nitrogen or argon.

  As a method of baking, the method of heating with an oven or a hotplate in inert gas or in a vacuum is mentioned.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. In addition, the used apparatus is as follows.
(1) ¹ H-NMR measurement: High resolution nuclear magnetic resonance apparatus manufactured by Varian (2) Substrate cleaning: Substrate cleaning apparatus manufactured by Choshu Sangyo Co., Ltd.
(3) Varnish application: Mikasa Co., Ltd. spin coater MS-A100
(4) Film thickness measurement: Fine shape measuring machine Surfcorder ET-4000 manufactured by Kosaka Laboratory Ltd.
(5) Transmittance measurement: visible ultraviolet absorption spectrum measuring device UV-3100PC manufactured by Shimadzu Corporation
(6) Production of EL element: Multi-function vapor deposition system C-E2L1G1-N manufactured by Choshu Industry Co., Ltd.
(7) Measurement of luminance of EL element, etc .: (Yes) Tech World I-V-L measurement system

[1] Synthesis of Compound [Synthesis Example 1] Synthesis of aniline derivative A (formula (f))

To a mixed suspension of 4,4′-diaminodiphenylamine 10.00 g (50.19 mmol), 4-bromotriphenylamine 34.17 g (105.40 mmol) and xylene 100 g, tetrakis (triphenylphosphine) palladium 0.5799 g (0.5018 mmol) and 10.13 g (105.40 mmol) of t-butoxy sodium were added, and the mixture was stirred at 130 ° C. for 14 hours under nitrogen.
Thereafter, the reaction mixture was filtered, and saturated brine was added to the filtrate for separation, and then the solid obtained by distilling off the solvent from the organic layer was recrystallized using 1,4-dioxane. An aniline derivative A was obtained (yield: 22.37 g, yield: 65%).

[Synthesis Example 2] Synthesis of arylsulfonic acid C (formula (8))

Under a nitrogen atmosphere, 11.0 g (31.59 mmol) of sodium 1-naphthol-3,6-disulfonate, which had been thoroughly dried, was charged with 4.797 g (14.36 mol) of perfluorobiphenyl and 4.167 g (30.30 mol) of potassium carbonate. 15 mol) and N, N-dimethylformamide (100 mL) were sequentially added, and the reaction system was purged with nitrogen, followed by stirring at an internal temperature of 100 ° C. for 6 hours.
After allowing to cool to room temperature, 500 mL of N, N-dimethylformamide was further added and stirred at room temperature for 90 minutes in order to redissolve the arylsulfonic acid C precipitated after the reaction. After completion of stirring, the solution was filtered to remove potassium carbonate residue and concentrated under reduced pressure. Furthermore, in order to remove the remaining impurities, 100 mL of methanol was added to the residue, and the mixture was stirred at room temperature for 30 minutes. After completion of the stirring, the suspension solution was filtered and the residue was collected by filtration. 300 mL of ultrapure water was added to the filtrate to dissolve it, and ion exchange was performed by column chromatography using a cation exchange resin Dowex 650C (manufactured by Dow Chemical Co., H type, approximately 200 mL, distillate solvent: ultrapure water). .
The fraction having a pH of 1 or less was concentrated to dryness under reduced pressure, and the residue was dried under reduced pressure to obtain arylsulfonic acid C (yield: 11 g, yield: 85%).

[2] Preparation of charge transporting varnish [Example 1-1]
0.029 g (0.042 mmol) of the aniline derivative A produced in Synthesis Example 1, 0.189 g (0.563 mmol) of N, N′-diphenylbenzidine (Tokyo Chemical Industry Co., Ltd.) and the aryl sulfonic acid produced in Synthesis Example 2 A mixture of 0.282 g (0.313 mmol) of C was dissolved in 17.5 g of 1,3-dimethyl-2-imidazolidinone under a nitrogen atmosphere. Thereto, 3.5 g of cyclohexanol and 3.5 g of propylene glycol were added and further stirred. The obtained solution was filtered using a PTFE filter having a pore size of 0.2 μm to obtain a charge transporting varnish. N, N′-diphenylbenzidine was recrystallized using 1,4-dioxane and dried well under reduced pressure before use in the preparation of varnish.

[Examples 1-2 to 1-7]
The amounts of aniline derivative A, N, N′-diphenylbenzidine and arylsulfonic acid C used were 0.056 g (0.082 mmol), 0.166 g (0.493 mmol) and 0.278 g (0.308 mmol) (implemented). Example 1-2); 0.083 g (0.121 mmol), 0.143 g (0.425 mmol) and 0.274 g (0.303 mmol) (Example 1-3); 0.109 g (0.159 mmol), 0 121 g (0.359 mmol) and 0.270 g (0.299 mmol) (Example 1-4); 0.054 g (0.078 mmol), 0.092 g (0.274 mmol) and 0.354 g (0.392 mmol) (Example 1-5); 0.071 g (0.104 mmol), 0.078 g (0.233 mmol) and And 0.351 g (0.388 mmol) (Example 1-6); and 0.088 g (0.128 mmol), 0.065 g (0.192 mmol) and 0.347 g (0.385 mmol) (Example 1-7) The charge transporting varnish was prepared in the same manner as in Example 1-1 except that.

[Comparative Example 1-1]
Of N, N′-diarylbenzidine derivative B represented by the formula (9) produced according to the method described in WO2008 / 032616 and 0.111 g (0.345 mmol) of arylsulfonic acid C The mixture was dissolved in 17.5 g of 1,3-dimethyl-2-imidazolidinone under a nitrogen atmosphere. Thereto, 3.5 g of cyclohexanol and 3.5 g of propylene glycol were added and further stirred. The obtained solution was filtered using a PTFE filter having a pore size of 0.2 μm to obtain a charge transporting varnish.

[Comparative Example 1-2]
A mixture of 0.031 g (0.045 mmol) of the aniline derivative A, 0.166 g (0.303 mmol) of the N, N′-diarylbenzidine derivative B and 0.304 g (0.336 mmol) of arylsulfonic acid C was added under a nitrogen atmosphere. -Dissolved in 17.5 g of dimethyl-2-imidazolidinone. Thereto, 3.5 g of cyclohexanol and 3.5 g of propylene glycol were added and further stirred. The obtained solution was filtered using a PTFE filter having a pore size of 0.2 μm to obtain a charge transporting varnish.

[Comparative Example 1-3]
An attempt was made to prepare a varnish using 0.742 g of N, N′-diphenylbenzidine, 17.5 g of 1,3-dimethyl-2-imidazolidinone, 3.5 g of cyclohexanol and 3.5 g of propylene glycol. It was not possible to obtain a uniform varnish that was suspended and could be used to form a charge transporting thin film for an organic EL device.

[3] Preparation of charge transporting thin film and transparency evaluation of thin film [Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-2]
The varnishes obtained in Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-2 were each applied to a quartz substrate using a spin coater, then dried in the atmosphere at 50 ° C. for 5 minutes, and further 230 Baking at 15 ° C. for 15 minutes formed a uniform thin film with a thickness of 30 nm on the quartz substrate. The quartz substrate was used after removing impurities on the surface using a plasma cleaning apparatus (150 W, 30 seconds).

  The transmittance of the prepared thin film was measured. The transmittance was scanned at a wavelength of 400 to 800 nm which is a visible light region. Table 1 shows the transmittance at 400, 500, 600, 700, and 800 nm, and the average transmittance at 400 to 800 nm.

  As shown in Table 1, the thin films prepared using the charge transporting varnishes of Examples 1-1 to 1-7 are varnishes (comparative examples) containing an oligoaniline compound whose conjugate system has been cut as a charge transporting material. The transmittance in the visible region was higher than that of the thin film prepared using 1-1 to 1-2).

[4] Manufacture and characteristic evaluation of organic EL device [Example 3-1]
The varnish obtained in Example 1-1 was applied to an ITO substrate using a spin coater, then dried at 50 ° C. for 5 minutes, and further baked at 230 ° C. for 15 minutes in an air atmosphere to be 30 nm on the ITO substrate. A uniform thin film was formed. As the ITO substrate, a glass substrate of 25 mm × 25 mm × 0.7 t in which indium tin oxide (ITO) is patterned on the surface with a film thickness of 150 nm is used, and an O ₂ plasma cleaning apparatus (150 W, 30 seconds) before use. To remove impurities on the surface.
Next, N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (α-) was applied to the ITO substrate on which the thin film was formed using a vapor deposition apparatus (vacuum degree: 1.0 × 10 ⁻⁵ Pa). NPD), tris (8-quinolinolato) aluminum (III) (Alq ₃ ), lithium fluoride, and aluminum thin films were sequentially laminated to obtain an organic EL device. At this time, the deposition rate is 0.2 nm / second for α-NPD, Alq ₃ and aluminum, and 0.02 nm / second for lithium fluoride, and the film thicknesses are 30 nm, 40 nm, and 0.2 nm, respectively. It was 5 nm and 120 nm.
In addition, in order to prevent the characteristic deterioration by the influence of oxygen in the air, water, etc., after sealing the organic EL element with the sealing substrate, the characteristic was evaluated. Sealing was performed according to the following procedure.
In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of −85 ° C. or less, the organic EL element was placed between the sealing substrates, and the sealing substrate was bonded with an adhesive (XNR5516Z-B1 manufactured by Nagase ChemteX Corporation). . Under the present circumstances, the water catching agent (Dynic Co., Ltd. product HD-071010W-40) was stored in the sealing substrate with the organic EL element. The bonded sealing substrate was irradiated with UV light (wavelength: 365 nm, irradiation amount: 6,000 mJ / cm ² ), and then annealed at 80 ° C. for 1 hour to cure the adhesive.

[Examples 3-2 to 3-7 and Comparative examples 3-1 to 3-2]
Instead of the varnish obtained in Example 1-1, Example 3-, except that the varnish obtained in Examples 1-2 to 1-7 and Comparative Examples 1-1 to 1-2 was used. The organic EL element was produced by the same method as 1.

[Comparative Example 3-3]
Instead of forming a thin film using varnish, it consists of N, N'-diphenylbenzidine on an ITO substrate by a vapor deposition method (deposition rate 0.2 nm / sec) using N, N'-diphenylbenzidine as a vapor deposition source. An organic EL element was produced in the same manner as in Example 3-1, except that a 30 nm uniform thin film was formed.

  The current density and luminance at a driving voltage of 5 V of the produced organic EL element were measured. The results are shown in Table 2.

  As shown in Table 2, the organic EL device of the example showed higher luminance than the device of the comparative example.

（式中、Ｒ¹は、それぞれ独立して、水素原子、Ｚ¹で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基、又はＺ²で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基を表し、
Ｒ²〜Ｒ⁷は、それぞれ独立して、水素原子、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基、カルボン酸基、Ｚ¹で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基、Ｚ²で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基、−ＮＨＹ¹、−ＮＹ²Ｙ³、−Ｃ(Ｏ)Ｙ⁴、−ＯＹ⁵、−ＳＹ⁶、−ＳＯ₃Ｙ⁷、−Ｃ(Ｏ)ＯＹ⁸、−ＯＣ(Ｏ)Ｙ⁹、−Ｃ(Ｏ)ＮＨＹ¹⁰又は−Ｃ(Ｏ)ＮＹ¹¹Ｙ¹²基を表し、
Ｙ¹〜Ｙ¹²は、それぞれ独立して、Ｚ¹で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基、又はＺ²で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基を表し、
Ｚ¹は、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基、カルボン酸基、又はＺ³で置換されていてもよい炭素数６〜２０のアリール基若しくは炭素数２〜２０のヘテロアリール基を表し、
Ｚ²は、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基、カルボン酸基、又はＺ³で置換されていてもよい炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基若しくは炭素数２〜２０のアルキニル基を表し、
Ｚ³は、ハロゲン原子、ニトロ基、シアノ基、アミノ基、アルデヒド基、水酸基、チオール基、スルホン酸基又はカルボン酸基を表し、
ｎは、２〜２０の整数を表す。）

［式中、Ｒ⁸〜Ｒ¹⁵は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基又は炭素数２〜２０のアルキニル基を表し、
Ａｒ¹及びＡｒ²は、それぞれ独立して、式（３）又は（４）で表される基を表す。

（式中、Ｒ¹⁶〜Ｒ²⁵は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基又は炭素数２〜２０のアルキニル基を表し、
Ｘ¹及びＸ²は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数２〜２０のアルケニル基、炭素数２〜２０のアルキニル基、ジフェニルアミノ基、１−ナフチルフェニルアミノ基、２−ナフチルフェニルアミノ基、ジ（１−ナフチル）アミノ基、ジ（２−ナフチル）アミノ基又は１−ナフチル−２−ナフチルアミノ基を表す。）］
２．Ｒ ¹ が、それぞれ独立して、水素原子、Ｚ ¹ で置換されていてもよい炭素数１〜２０のアルキル基又はＺ ² で置換されていてもよい炭素数６〜２０のアリール基であり、
Ｒ ² 〜Ｒ ⁵ が、それぞれ独立して、水素原子、ハロゲン原子、Ｚ ¹ で置換されていてもよい炭素数１〜１０のアルキル基又はＺ ² で置換されていてもよい炭素数６〜１４のアリール基であり、
Ｒ ⁶ 及びＲ ⁷ が、それぞれ独立して、水素原子、ハロゲン原子、Ｚ ¹ で置換されていてもよい炭素数１〜１０のアルキル基、Ｚ ² で置換されていてもよい炭素数６〜１４のアリール基又はＺ ² で置換されていてもよいジフェニルアミノ基であり、
Ｒ ⁸ 〜Ｒ ²⁵ が、それぞれ独立して、水素原子又は炭素数１〜２０のアルキル基であり、
Ｘ ¹ 及びＸ ² が、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、ジフェニルアミノ基、１−ナフチルフェニルアミノ基、２−ナフチルフェニルアミノ基、ジ（１−ナフチル）アミノ基、ジ（２−ナフチル）アミノ基又は１−ナフチル−２−ナフチルアミノ基である１の電荷輸送性ワニス。
３．Ｒ ¹ が、それぞれ独立して、水素原子、Ｚ ¹ で置換されていてもよい炭素数１〜１０のアルキル基又はＺ ² で置換されていてもよい炭素数６〜１４のアリール基であり、
Ｒ ² 〜Ｒ ⁵ が、それぞれ独立して、水素原子、ハロゲン原子又はＺ ¹ で置換されていてもよい炭素数１〜１０のアルキル基であり、
Ｒ ⁶ 及びＲ ⁷ が、それぞれ独立して、水素原子、ハロゲン原子、Ｚ ¹ で置換されていてもよい炭素数１〜１０のアルキル基又はＺ ² で置換されていてもよいジフェニルアミノ基であり、
Ｒ ⁸ 〜Ｒ ²⁵ が、それぞれ独立して、水素原子又は炭素数１〜１０のアルキル基であり、
Ｘ ¹ 及びＸ ² が、それぞれ独立して、水素原子、ジフェニルアミノ基、１−ナフチルフェニルアミノ基、２−ナフチルフェニルアミノ基、ジ（１−ナフチル）アミノ基、ジ（２−ナフチル）アミノ基又は１−ナフチル−２−ナフチルアミノ基である２の電荷輸送性ワニス。
４．Ｒ ¹ が、それぞれ独立して、水素原子、Ｚ ¹ で置換されていてもよい炭素数１〜４のアルキル基又はＺ ² で置換されていてもよいフェニル基であり、
Ｒ ⁶ 及びＲ ⁷ が、それぞれ独立して、水素原子又はＺ ² で置換されていてもよいジフェニルアミノ基であり、
Ｒ ⁸ 〜Ｒ ²⁵ が、それぞれ独立して、水素原子又は炭素数１〜６のアルキル基であり、
Ｘ ¹ 及びＸ ² が、それぞれ独立して、水素原子又はジフェニルアミノ基である３の電荷輸送性ワニス。
５．Ｒ ¹ が、水素原子であり、
Ｒ ² 〜Ｒ ⁵ が、それぞれ独立して、水素原子又はハロゲン原子であり、
Ｒ ⁶ 及びＲ ⁷ が、それぞれ独立して、水素原子又はジフェニルアミノ基であり、
Ｒ ⁸ 〜Ｒ ²⁵ が、それぞれ独立して、水素原子又は炭素数１〜４のアルキル基である４の電荷輸送性ワニス。
６．Ｒ ¹ 〜Ｒ ⁵ 及びＲ ⁸ 〜Ｒ ²⁵ が、全て水素原子であり、Ｒ ⁶ 及びＲ ⁷ が、ともに水素原子又はジフェニルアミノ基である５の電荷輸送性ワニス。
７．Ｘ ¹ 及びＸ ² が、全て水素原子である４〜６のいずれかの電荷輸送性ワニス。
８．前記オリゴアニリン誘導体が、式（ａ）〜（ｉ）のいずれかで表され、前記Ｎ，Ｎ'−ジアリールベンジジン誘導体が、式（ｊ）〜（ｍ）のいずれかで表される１の電荷輸送性ワニス。

９．１〜８のいずれかの電荷輸送性ワニスを用いて作製される電荷輸送性薄膜。
１０．９の電荷輸送性薄膜を有する電子デバイス。
１１．９の電荷輸送性薄膜を有する有機ＥＬ素子。
１２．前記電荷輸送性薄膜が、正孔注入層又は正孔輸送層である１１の有機ＥＬ素子。
１３．１〜８のいずれかの電荷輸送性ワニスを基材上に塗布して焼成することを特徴とする電荷輸送性薄膜の製造方法。
１４．９の電荷輸送性薄膜を用いることを特徴とする有機ＥＬ素子の製造方法。 That is, the present invention provides the following charge transporting varnish.
1. It comprises a charge transporting substance comprising an oligoaniline derivative represented by the formula (1), a charge transporting substance comprising an N, N′-diarylbenzidine derivative represented by the formula (2), a dopant and an organic solvent. Charge transport varnish.

(In the formula, each R ¹ independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms. A group, or 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 ² ;
R ^{2 to} R ⁷ are each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or Z ^1. May be 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, an aryl group having 6 to 20 carbon atoms which may be substituted with Z ² , or 2 carbon atoms. ˜20 heteroaryl groups, —NHY ¹ , —NY ² Y ³ , —C (O) Y ⁴ , —OY ⁵ , —SY ⁶ , —SO ₃ Y ⁷ , —C (O) OY ⁸ , —OC ( O) represents ^{Y 9, -C (O) NHY} 10 or -C (O) NY ¹¹ Y ¹² group,
Y ^{1 to} Y ¹² are each independently 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 ¹ , or Z ² 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 ² ,
Z ¹ is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an aryl group having 6 to 20 carbon atoms that may be substituted with Z ^3. Or represents a C2-C20 heteroaryl group,
Z ² is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an alkyl group having 1 to 20 carbon atoms that may be substituted with Z ³ Represents an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms,
Z ³ represents a halogen atom, nitro group, cyano group, amino group, aldehyde group, hydroxyl group, thiol group, sulfonic acid group or carboxylic acid group,
n represents an integer of 2 to 20. )

[Wherein, R ^{8 to} R ¹⁵ each independently 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,
Ar ¹ and Ar ² each independently represent a group represented by the formula (3) or (4).

(Wherein R ^{16 to} R ²⁵ each independently 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,
X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a diphenylamino group, or 1-naphthylphenyl. It represents an amino group, 2-naphthylphenylamino group, di (1-naphthyl) amino group, di (2-naphthyl) amino group or 1-naphthyl-2-naphthylamino group. ]]
2. Each R ¹ is independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , or an aryl group having 6 to 20 carbon atoms which may be substituted with Z ² ;
R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms that may be substituted with Z ¹ , or 6 to 14 carbon atoms that may be substituted with Z ^2. An aryl group of
R ⁶ and R ⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms that may be substituted with Z ¹ , or 6 to 14 carbon atoms that may be substituted with Z ^2. An aryl group or a diphenylamino group optionally substituted with Z ² ,
R ^{8 to} R ²⁵ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms,
X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a diphenylamino group, a 1-naphthylphenylamino group, a 2-naphthylphenylamino group, or a di (1-naphthyl) amino group. 1, a charge transporting varnish which is a di (2-naphthyl) amino group or a 1-naphthyl-2-naphthylamino group.
3. Each R ¹ is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or an aryl group having 6 to 14 carbon atoms which may be substituted with Z ² ;
R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ ;
R ⁶ and R ⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms that may be substituted with Z ¹ , or a diphenylamino group that may be substituted with Z ² . ,
R ^{8 to} R ²⁵ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
X ¹ and X ² are each independently a hydrogen atom, diphenylamino group, 1-naphthylphenylamino group, 2-naphthylphenylamino group, di (1-naphthyl) amino group, di (2-naphthyl) amino group Or 2 charge transportable varnish which is 1-naphthyl-2-naphthylamino group.
4). Each R ¹ is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms that may be substituted with Z ¹ , or a phenyl group that may be substituted with Z ² ;
R ⁶ and R ⁷ are each independently a hydrogen atom or a diphenylamino group optionally substituted with Z ² ;
R ^{8 to} R ²⁵ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
3. The charge transporting varnish of 3, wherein X ¹ and X ² are each independently a hydrogen atom or a diphenylamino group.
5. R ¹ is a hydrogen atom,
R ^{2 to} R ⁵ are each independently a hydrogen atom or a halogen atom,
R ⁶ and R ⁷ are each independently a hydrogen atom or a diphenylamino group,
R ⁸ to R ²⁵ are each independently, fourth charge-transporting varnish is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
6). 5. The charge transporting varnish of ^5, wherein R ^{1 to} R ⁵ and R ^{8 to} R ²⁵ are all hydrogen atoms, and R ⁶ and R ⁷ are both hydrogen atoms or diphenylamino groups.
7). The charge transporting varnish according to any one of 4 to 6, wherein X ¹ and X ² are all hydrogen atoms.
8). The charge of 1 wherein the oligoaniline derivative is represented by any one of formulas (a) to (i) and the N, N′-diarylbenzidine derivative is represented by any one of formulas (j) to (m) Transportable varnish.

9 . A charge transporting thin film produced using the charge transporting varnish of any one of 1 to 8 .
10 . An electronic device having nine charge transporting thin films.
11 . 9. An organic EL device having 9 charge transporting thin films.
12 . 11. The organic EL element according to 11 , wherein the charge transporting thin film is a hole injection layer or a hole transport layer.
13 . A method for producing a charge-transporting thin film, comprising applying the charge-transporting varnish of any one of 1 to 8 onto a substrate and baking.
14 . 9. A method for producing an organic EL device, comprising using the charge transporting thin film of No. 9 .

In the present invention, as the oligoaniline derivative, a commercially available product may be used, or one synthesized by a known method may be used. The synthesis method is not particularly limited. For example, Bulletin of Chemical Society of Japan (1994, Vol. 67, pp. 1749-1752), Synthetic Metals (Synthetic Metals). Metals) (1997 year, Vol. 84, pp.119-120), International Publication No. WO 2008/032617, International Publication No. 2008 / 032,616, include a method described in International Publication No. 2008 / 129,947 Patent, and the like.

Examples of oligoaniline derivatives that can be suitably used in the present invention include, but are not limited to, the following.

The high-viscosity organic solvent, cyclohexanol, ethylene glycol, ethylene glycol di grayed glycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, Examples 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 hole transporting polymer material, poly [(9,9-dihexyl-2,7-diyl)-co-(N, N'-bis {p-butylphenyl} -1,4-diamino Phenylene)], 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 polysilsesquioxane, poly [(9, 9-Didioctylfluorenyl-2,7-diyl) -co- ( 4,4 ′-(N- (p-butylphenyl)) diphenylamine)] and the like.

Claims (7)

It comprises a charge transporting substance comprising an oligoaniline derivative represented by the formula (1), a charge transporting substance comprising an N, N′-diarylbenzidine derivative represented by the formula (2), a dopant and an organic solvent. Charge transport varnish.

(In the formula, each R ¹ independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms. A group, or 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 ² ;
R ^{2 to} R ⁷ are each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or Z ^1. May be 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, an aryl group having 6 to 20 carbon atoms which may be substituted with Z ² , or 2 carbon atoms. ˜20 heteroaryl groups, —NHY ¹ , —NY ² Y ³ , —C (O) Y ⁴ , —OY ⁵ , —SY ⁶ , —SO ₃ Y ⁷ , —C (O) OY ⁸ , —OC ( O) represents ^{Y 9, -C (O) NHY} 10 or -C (O) NY ¹¹ Y ¹² group,
Y ^{1 to} Y ¹² are each independently 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 ¹ , or Z ² 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 ² ,
Z ¹ is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an aryl group having 6 to 20 carbon atoms that may be substituted with Z ^3. Or represents a C2-C20 heteroaryl group,
Z ² is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an alkyl group having 1 to 20 carbon atoms that may be substituted with Z ³ Represents an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms,
Z ³ represents a halogen atom, nitro group, cyano group, amino group, aldehyde group, hydroxyl group, thiol group, sulfonic acid group or carboxylic acid group,
n represents an integer of 2 to 20. )

[Wherein, R ^{8 to} R ¹⁵ each independently 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,
Ar ¹ and Ar ² each independently represent a group represented by the formula (3) or (4).

(Wherein R ^{16 to} R ²⁵ each independently 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,
X ¹ and X ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a diphenylamino group, or 1-naphthylphenyl. It represents an amino group, 2-naphthylphenylamino group, di (1-naphthyl) amino group, di (2-naphthyl) amino group or 1-naphthyl-2-naphthylamino group. ]]   A charge transporting thin film produced using the charge transporting varnish according to claim 1.   An electronic device comprising the charge transporting thin film according to claim 2.   An organic electroluminescence device comprising the charge transporting thin film according to claim 2.   The organic electroluminescence device according to claim 4, wherein the charge transporting thin film is a hole injection layer or a hole transport layer.   A method for producing a charge-transporting thin film, comprising applying the charge-transporting varnish according to claim 1 onto a substrate and baking.   A method for producing an organic electroluminescent element, comprising using the charge transporting thin film according to claim 2.