WO2020262419A1

WO2020262419A1 - Charge-transporting varnish

Info

Publication number: WO2020262419A1
Application number: PCT/JP2020/024704
Authority: WO
Inventors: 将之東
Original assignee: 日産化学株式会社
Priority date: 2019-06-26
Filing date: 2020-06-24
Publication date: 2020-12-30
Also published as: JPWO2020262419A1; TW202115202A; CN114008147A; KR20220025814A; CN114008147B

Abstract

Provided is a charge-transporting varnish that includes a monodisperse charge-transporting organic compound (A), a dopant (B), and an organic solvent (C). The dopant (B) includes: an aryl sulfonic acid ester compound (B1); and halogenated tetracyanoquinodimethane (B2) or halogenated or cyanated benzoquinone (B3).

Description

Charge transport varnish

The present invention relates to a charge transporting varnish.

The method for forming an organic functional layer such as a hole injection layer used in an organic electroluminescence (EL) device is roughly classified into a dry process represented by a vapor deposition method and a wet process represented by a spin coating method. Comparing each of these processes, the wet process can efficiently produce a thin film having a large area and high flatness. Therefore, at present, the area of organic EL displays is being increased, and a hole injection layer that can be formed by a wet process is desired. In view of these circumstances, the applicant has applied a charge transporting material that can be applied to various wet processes and provides a thin film capable of realizing excellent EL device characteristics when applied to a hole injection layer of an organic EL device. In addition, we have been developing compounds with good solubility in organic solvents used for them (see, for example, Patent Documents 1 to 3).

In the manufacture of organic EL displays, when a hole injection layer or other organic functional layer is formed by a wet process, a partition wall (bank) is generally provided so as to surround the layer formation region, and a partition wall (bank) is provided in the opening of the partition wall. Organic functional ink is applied. At this time, the ink applied in the opening may crawl up on the side surface of the partition wall, and the thickness of the peripheral portion of the coating film in contact with the side surface of the partition wall may be thicker than that of the central portion of the coating film, so-called crawling phenomenon may occur. .. When such a crawling phenomenon occurs, the plurality of organic functional layers formed between the electrodes do not function in the order of stacking, causing a situation in which a leak current path is formed. As a result, the desired device characteristics cannot be realized. Further, the organic functional layer such as the crawling hole injection layer may cause uneven light emission of the obtained organic EL element. Patent Documents 4 and 5 propose means for suppressing the crawling phenomenon, but in response to the recent situation in which the development of organic EL displays using a wet process is further accelerated, the suppression of such a crawling phenomenon is suppressed. The demand for technology related to is increasing.

International Publication No. 2008/129947 International Publication No. 2015/050253 International Publication No. 2017/217457 JP-A-2009-104859 Japanese Unexamined Patent Publication No. 2011-103222

The present invention has been made in view of the above circumstances, and is a charge-transporting varnish that does not cause a creep-up phenomenon, and has excellent characteristics when a thin film obtained from the varnish is applied to a hole injection layer or the like. It is an object of the present invention to provide a charge transporting varnish capable of realizing an organic EL device.

As a result of diligent studies to achieve the above object, the present inventor has obtained (A) a monodisperse charge-transporting organic compound, (B) a dopant containing two predetermined compounds, and (C) an organic solvent. The present invention has been completed by finding that when the charge-transporting varnish containing the varnish is applied into the partition wall by a wet process, the creeping up of the varnish is extremely suppressed.

That is, the present invention provides the following charge transporting varnish.
1. 1. A charge-transporting varnish containing (A) a monodisperse charge-transporting organic compound, (B) a dopant, and (C) an organic solvent.
A charge-transporting varnish in which the dopant (B) comprises (B1) an aryl sulfonic acid ester compound and (B2) a halogenated tetracyanoquinodimethane or (B3) a halogenated or cyanated benzoquinone.
2. 2. The charge-transporting varnish of 1 in which the monodisperse charge-transporting organic compound is an arylamine derivative.
3. 3. 2. Transport varnish of 2 in which the arylamine derivative is a tertiary arylamine compound.
4. 3. A charge-transporting varnish of 3, wherein the tertiary arylamine compound has at least one nitrogen atom and all nitrogen atoms have a tertiary arylamine structure.
5. 4. The charge-transporting varnish of 4, wherein the tertiary arylamine compound has at least two nitrogen atoms and all nitrogen atoms have a tertiary arylamine structure.
6. A charge-transporting varnish according to any one of 1 to 5, wherein the aryl sulfonic acid ester compound is represented by the following formula (B1) or (B1').

[In the formula, A ¹ may have a substituent and is represented by an m-valent hydrocarbon group having 6 to 20 carbon atoms containing one or more aromatic rings or the following formula (B1a) or (B1b). Is an m-valent group derived from the compound to be

(In the formula, W ¹ and W ² may independently have -O-, -S-, -S (O)-or -S (O ₂ )-, or -N. -, -Si-, -P- or -P (O)-)
A ² is -O-, -S- or -NH-;
A ³ is, or an (n + 1) -valent aromatic group with 6 to 20 carbon atoms;
X ¹ is an alkylene group having 2 to 5 carbon atoms, and an —O—, —S— or carbonyl group may be interposed between the carbon atoms of the alkylene group, and one of the hydrogen atoms of the alkylene group. Part or all may be further substituted with an alkyl group having 1 to 20 carbon atoms;
X ² is a single bond, -O-, -S- or -NR-, and R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms;
X ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent;
m is an integer that satisfies 1 ≦ m ≦ 4.
n is an integer that satisfies 1 ≦ n ≦ 4. ]
7. The charge transporting varnish of 6 in which the aryl sulfonic acid ester compound is represented by any of the following formulas (B1-1) to (B1-3).

(In the formula, 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 may have a substituent. It is a monovalent hydrocarbon group having 2 to 20 carbon atoms;
A ¹¹ is an m-valent group derived from perfluorobiphenyl, A ¹² is an -O- or -S-, and A ¹³ is a (n + 1) -valent group derived from naphthalene or anthracene. Yes;
m and n are the same as described above. )

(In the formula, R ^s6 and R ^s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group, and R ^s8 is a linear or branched monovalent fat. Although it is a group hydrocarbon group, the total number of carbon atoms of R ^s6 , R ^s7 and R ^s8 is 6 or more;
A ¹⁴ is an m-valent hydrocarbon group containing one or more aromatic rings, which may have a substituent, A ¹⁵ is —O— or —S—, and A ¹⁶ is ( It is an n + 1) valent aromatic group;
m and n are the same as described above. )

(In the formula, R ^s9 to R ^s13 are independently hydrogen atom, nitro group, cyano group, halogen atom, alkyl group having 1 to 10 carbon atoms, alkyl halide group having 1 to 10 carbon atoms, or carbon number of carbon atoms. 2-10 halogenated alkenyl groups;
R ^s14 to R ^s17 are independently hydrogen atoms or linear or branched monovalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms;
R ^s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or −OR ^s19 , and R ^s19 has 2 to 20 carbon atoms which may have a substituent. Is a monovalent hydrocarbon group of
A ¹⁷ is -O-, -S- or -NH-;
A ¹⁸ is an (n + 1) -valent aromatic group;
n is the same as described above. )
8. (B2) A charge-transporting varnish according to any one of 1 to 7, wherein the halogenated tetracyanoquinodimethane is represented by the following formula (B2).

(In the formula, R ^q1 to R ^q4 are independently hydrogen atoms or halogen atoms, but at least one is a halogen atom.)
9. (B3) A charge-transporting varnish according to any one of 1 to 8, wherein the halogenated or cyanated benzoquinone is represented by the following formula (B3).

(In the formula, R ^q5 to R ^q8 are independently hydrogen atoms, halogen atoms or cyano groups, but at least one is a halogen atom or cyano group.)
10. The content of the (B1) aryl sulfonic acid ester compound is 0.01 to 50 in molar ratio with respect to the (B2) halogenated tetracyanoquinodimethane or the (B3) halogenated or cyanated benzoquinone. A charge transporting varnish of any one of 1-9.
11. A charge-transporting varnish according to any one of 1 to 10, wherein the monodisperse charge-transporting organic compound has a molecular weight of 200 to 9,000.
12. The charge transporting varnish according to any one of 1 to 11, wherein the organic solvent contains a low-polarity organic solvent.
A charge-transporting thin film obtained from any of the charge-transporting varnishes of 13.1-12.
An organic EL device including a charge transporting thin film of 14.13.
15. 14 organic EL devices in which the charge transporting thin film is a hole injection layer or a hole transport layer.

By using the charge-transporting varnish of the present invention, it is possible to produce a charge-transporting thin film in which the varnish creeps up (so-called pile-up) is extremely suppressed even when it is applied into the partition wall by a wet process. Further, the charge-transporting thin film obtained from the charge-transporting varnish of the present invention is excellent in flatness and charge-transporting property. Therefore, the charge transporting varnish of the present invention can be suitably used for producing a thin film for an electronic device including an organic EL device, particularly a thin film for an organic EL display.

[Charge transport varnish]
The charge transport varnish of the present invention is a charge transport varnish containing (A) a monodisperse charge transport organic compound, (B) a dopant and (C) an organic solvent, and (B) the dopant is (B1). It contains an aryl sulfonic acid ester compound and (B2) halogenated tetracyanoquinodimethane or (B3) halogenated or cyanated benzoquinone.

[(A) Charge-transporting organic compound]
In the present invention, as the charge transporting organic compound, for example, those conventionally used in the field of organic EL can be used. Specific examples thereof include arylamine derivatives (aniline derivatives) such as oligoaniline derivatives, N, N'-diarylbenzidine derivatives, N, N, N', N'-tetraarylbenzidine derivatives, oligothiophene derivatives, and thienothiophene derivatives. , Thionophen derivatives such as thienobenzothiophene derivatives, and various charge-transporting organic compounds such as pyrrole derivatives such as oligopyrrole. Of these, arylamine derivatives and thiophene derivatives are preferable.

In the present invention, the charge-transporting organic compound needs to be monodisperse (that is, the molecular weight distribution is 1). When an oligomer or polymer having a molecular weight distribution is used, the effect of suppressing the creep-up phenomenon becomes insufficient. The molecular weight of the charge-transporting organic compound is usually about 200 to 9,000 from the viewpoint of preparing a uniform varnish that gives a thin film having high flatness, but 300 from the viewpoint of obtaining a thin film having more excellent charge-transporting property. The above is preferable, 400 or more is more preferable, and from the viewpoint of preparing a uniform varnish that gives a thin film having high flatness with better reproducibility, 8,000 or less is preferable, 7,000 or less is more preferable, and 6,000 or less is preferable. Even more preferably, 5,000 or less is even more preferable.

Examples of the charge-transporting organic compound include JP-A-2002-151272, International Publication No. 2004/105446, International Publication No. 2005/043962, International Publication No. 2008/032617, and International Publication No. 2008/032616. , International Publication No. 2013/0426223, International Publication No. 2014/141998, International Publication No. 2014/185208, International Publication No. 2015/050253, International Publication No. 2015/137391, International Publication No. 2015/137395, International Publication No. Examples thereof are those disclosed in Publication No. 2015/146912, International Publication No. 2015/146965, International Publication No. 2016/190326, International Publication No. 2016/136544, International Publication No. 2016/204079, and the like.

Further, as the charge transporting organic compound, a tertiary arylamine compound having at least one nitrogen atom and all nitrogen atoms having a tertiary arylamine structure is also preferable. That is, the tertiary arylamine compound has at least one nitrogen atom and has a structure in which three aromatic groups are bonded to all the nitrogen atoms. The tertiary arylamine compound preferably has two or more nitrogen atoms.

Preferable examples of the tertiary arylamine compound include a compound represented by the following formula (A1) or (A2).

In the formula (A2), R ¹ and R ² are independently substituted with a hydrogen atom, a halogen atom, a nitro group or a cyano group, or a halogen atom, respectively, an alkyl group having 1 to 20 carbon atoms, and carbon. It is 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.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

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, and isobutyl. Group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, etc. with 1 to 20 carbon atoms. Chain or 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 , Bicyclooctyl group, bicyclononyl group, bicyclodecyl group and other cyclic alkyl groups having 3 to 20 carbon atoms.

The alkenyl group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include a vinyl group, an n-1-propenyl group, an n-2-propenyl group and 1-methyl. Vinyl group, n-1-butenyl group, n-2-butenyl group, n-3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylvinyl group, 1-methyl Examples thereof include a -1-propenyl group, a 1-methyl-2-propenyl group, an n-1-pentenyl group, an n-1-decenyl group, an n-1-eicosenyl group and the like.

The alkynyl group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include an ethynyl group, an n-1-propynyl group, an n-2-propynyl group and an n-1. -Butynyl group, n-2-butynyl group, 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 group, Examples thereof include an n-1-decynyl group, an n-1-pentadecynyl group, and an n-1-eicosynyl group.

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

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 and 3-. Isooxazolyl group, 4-isoxazolyl group, 5-isooxazolyl group, 2-thiazolyl group, 4-thiazolyl group, 5-thiazolyl group, 3-isothiazolyl group, 4-isothiazolyl group, 5-isothiazolyl group, 2-imidazolyl group, 4- Examples thereof include an imidazolyl group, a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group.

Of these, R ¹ and R ² include an alkyl group having 1 to 20 carbon atoms which may be substituted with a hydrogen atom, a fluorine atom, a cyano group and a halogen atom, and a carbon number which may be substituted with a halogen atom. An aryl group of 6 to 20 or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with a halogen atom is preferable, and a heteroaryl group having 1 carbon atom which may be substituted with a hydrogen atom, a fluorine atom, a cyano group or a halogen atom is preferable. A phenyl group which may be substituted with an alkyl group of to 10 or a halogen atom is more preferable, a hydrogen atom or a fluorine atom is more preferable, and a hydrogen atom is the most suitable.

In the formulas (A1) and (A2), Ph ¹ is a group represented by the formula (P1).

In the formula (P1), the broken line is a bond. R ³ to R ⁶ are each independently substituted with a hydrogen atom, a halogen atom, a nitro group or a cyano group, or a halogen atom, an alkyl group having 1 to 20 carbon atoms, and an alkenyl having 2 to 20 carbon atoms. A group, 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. Specific examples of these include the same as those described in the description of R ¹ and R ² .

In particular, R ³ to R ⁶ include an alkyl group having 1 to 20 carbon atoms which may be substituted with a hydrogen atom, a fluorine atom, a cyano group and a halogen atom, and 6 to 6 carbon atoms which may be substituted with a halogen atom. A heteroaryl group having 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with a halogen atom is preferable, and a heteroaryl group having 1 to 10 carbon atoms which may be substituted with a hydrogen atom, a fluorine atom, a cyano group or a halogen atom is preferable. The alkyl group or the phenyl group which may be substituted with the halogen atom is more preferable, the hydrogen atom or the fluorine atom is more preferable, and the hydrogen atom is the most suitable.

Suitable groups for Ph ¹ include, but are not limited to, 1,4-phenylene groups.

In the formula (A1), Ar ¹ is a group independently represented by any of the following formulas (Ar1-1) to (Ar1-11), and in particular, the following formulas (Ar1-1') to (Ar1-1') to ( A group represented by any one of Ar1-11') is preferable.

In the formulas (Ar1-1) to (Ar1-11) and the formulas (Ar1-1') to (Ar1-11'), the broken line is a bond. R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ may be independently substituted with a hydrogen atom, a halogen atom, a nitro group or a cyano group, or a halogen atom, a diphenylamino group, respectively. It is 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, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms. R ²⁸ and R ²⁹ are aryl groups having 6 to 20 carbon atoms or heteroaryl groups having 2 to 20 carbon atoms, which may be independently substituted with Z ¹ . R ⁵² 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 ¹ .

Z ¹ is 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 a halogen atom, a nitro group or a cyano group, or Z ^2. Is. Z ² 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 a halogen atom, a nitro group or a cyano group, or Z ³ . Z ³ is a halogen atom, a nitro group or a cyano group.

In particular, R ⁷ to R ²⁷ , R ³⁰ to R ⁵¹ and R ⁵³ to R ¹⁵⁴ are substituted with a diphenylamino group or a halogen atom which may be substituted with a hydrogen atom, a fluorine atom, a cyano group or a halogen atom. An alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms which may be substituted with a halogen atom, or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with a halogen atom may be used. Preferably, an alkyl group having 1 to 10 carbon atoms which may be substituted with a hydrogen atom, a fluorine atom, a cyano group or a halogen atom, or a phenyl group which may be substituted with a halogen atom is more preferable, and a hydrogen atom or a fluorine atom is preferable. Is even more preferred, and a hydrogen atom is optimal.

As R ²⁸ and R ²⁹ , an aryl group having 6 to 14 carbon atoms which may be substituted with a halogen atom or a heteroaryl group having 2 to 14 carbon atoms which may be substituted with a halogen atom is preferable, and a halogen atom. A phenyl group optionally substituted with, or a naphthyl group optionally substituted with a halogen atom is more preferred, a phenyl group optionally substituted with a halogen atom is even more preferred, and a phenyl group is even more preferred.

As R ^52, a hydrogen atom is preferably an aryl group of Z ¹ is carbon atoms 6 also be ~ 20 substituted by a hydrogen atom, an optionally substituted phenyl group Z ^1, or substituted with Z ¹ A good naphthyl group is more preferred, a phenyl group which may be substituted with Z ¹ is even more preferred, and a phenyl group is even more preferred.

In the formulas (Ar1-10), (Ar1-11), (Ar1-10') and (Ar1-11'), Ar ⁴ is independently composed of an aryl group having 6 to 20 carbon atoms. It is an aryl group having 6 to 20 carbon atoms which may be substituted with a certain diallylamino group. Specific examples of the aryl group having 6 to 20 carbon atoms include those similar to those described in R ¹ and R ² above. Specific examples of the diarylamino group include a diphenylamino group, a 1-naphthylphenylamino group, a di (1-naphthyl) amino group, a 1-naphthyl-2-naphthylamino group, a di (2-naphthyl) amino group and the like. Can be mentioned.

Ar ⁴ includes phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthril group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4- Phenantryl group, 9-phenanthryl group, p- (diphenylamino) phenyl group, p- (1-naphthylphenylamino) phenyl group, p- (di (1-naphthyl) amino) phenyl group, p- (1-naphthyl-) 2-Phenylamino) phenyl group, p- [di (2-naphthyl) amino] phenyl group and the like are preferable, and p- (diphenylamino) phenyl group is more preferable.

In the formula (A1), Ar ² is a group independently represented by any of the formulas (Ar2-1) to (Ar2-18), and in particular, the formulas (Ar2-1'-1) to (Ar2-1'-1) to ( The group represented by any one of Ar2-18'-2) is preferable. In the following formula, Ar ⁴ is the same as described above, DPA is a diphenylamino group, and the broken line is a bond.

In formulas (Ar2-16), (Ar2-16'-1) and (Ar2-16'-2), R ¹⁵⁵ is a hydrogen atom, an aryl group having 6 to 14 carbon atoms which may be substituted with Z ^1. , Or a heteroaryl group having 2 to 14 carbon atoms which may be substituted with Z ¹ . Examples of the aryl group and the heteroaryl group include those similar to those described in the description of R ¹ and R ² . Among these, R ^155, a hydrogen atom, Z ¹ optionally substituted by a phenyl group, Z ¹ in optionally substituted 1-naphthyl group, which may have been or 2-naphthyl substituted with Z ¹ group, may be substituted with Z ¹ in optionally substituted 2-pyridyl group, optionally substituted 3-pyridyl group by a phenyl group which may be substituted with Z ^1, or Z ¹ 4 A pyridyl group is preferred, a phenyl group which may be substituted with Z ¹ is even more preferred, and a phenyl group or a (2,3,5,6-tetrafluoro-4- (trifluoromethyl) phenyl) group is even more preferred. ..

In formulas (Ar2-17), (Ar2-17'-1) and (Ar2-17'-2), R ¹⁵⁶ and R ¹⁵⁷ may be substituted with a phenyl group which may be substituted with Z ^1. A good aryl group having 6 to 14 carbon atoms and a heteroaryl group having 2 to 14 carbon atoms which may be substituted with a phenyl group which may be substituted with Z ¹ . Examples of the aryl group and the heteroaryl group include those similar to those described in the description of R ¹ and R ² . Of these, R ¹⁵⁶ and R ^157, an aryl group optionally having 6 to 14 carbon atoms is preferably substituted by a phenyl group which may be substituted with Z ^1, which may be substituted with Z ¹ A phenyl group optionally substituted with a phenyl group, a ¹ -naphthyl group optionally substituted with a Z ¹ or a 2-naphthyl group optionally substituted with a Z ¹ or a 2-naphthyl group optionally substituted with Z ¹ More preferred.

In the formula (A2), Ar ³ is a group represented by any of the formulas (Ar3-1) to (Ar3-8), and in particular, in the formulas (Ar3-1') to (Ar3-8'). The group represented by either is preferable. In the following formula, DPA is the same as described above, and the broken line is the bond.

In the formula (A1), p is an integer of 1 to 10, but from the viewpoint of increasing 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 even more preferable. 1 is optimal. In formula (A2), q is 1 or 2.

The aniline derivative represented by the formula (A1) and the aniline derivative represented by the formula (A2) can be produced, for example, according to the method described in International Publication No. 2015/050253.

Other suitable examples of the tertiary arylamine compound include, for example, a compound represented by the following formula (A3).

In formula (A3), r is an integer of 2-4. Ar ¹¹ is an r-valent aromatic group having 6 to 20 carbon atoms which may be substituted. The aromatic group is a group obtained by removing r hydrogen atoms from the aromatic ring of an aromatic compound having 6 to 20 carbon atoms. As the aromatic group, a group derived from a compound represented by any of the following formulas (A3-1) to (A3-8) is particularly preferable.

Wherein (A3-3) and ^{(A3-4), L 1 ~ L} 3 are each independently a single ^{^{bond, - (CR 201 R 202)}} s -, - C (O) -, - O -, - S -, - S (O) -, - S (O 2) - or -NR ²⁰³ - a. s is an integer from 1 to 6. Wherein (A3-5) ~ (A3-8), L 4 ~ L 13 each independently represent a single ^{^{bond, -CR 201 R 202 -, -}} C (O) -, - O -, - S-, -S (O) -, - S (O 2) - or -NR ²⁰³ - a. R ²⁰¹ and R ²⁰² are independently hydrogen atoms or monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R ²⁰¹ and R ²⁰² are bonded to each other to form a ring together with the carbon atom to which they are bonded. You may be doing it. In − (CR ²⁰¹ R ²⁰² ) _s −, when s is 2 or more, each R ²⁰¹ and R ²⁰² may be the same or different from each other. R ²⁰³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms.

Further, the aromatic group may have a part or all of its hydrogen atom further substituted with a substituent. Examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a hydroxy group, an amino group, a silanol group, a thiol group, a carboxy group, a sulfonic acid ester group, a phosphoric acid group and a phosphoric acid. Examples thereof include an ester group, an ester group, a thioester group, an amide group, a monovalent hydrocarbon group, an organooxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group and a sulfo group. A cyano group or a monovalent hydrocarbon group having 1 to 20 carbon atoms is preferable.

As Ar ¹¹ , 1,4-phenylene group, fluorene-2,7-diyl group, 9,9-dimethylfluorene-2,7-diyl group and the like which may be substituted are preferable, and even if they are substituted. Good, 1,4-phenylene group or biphenyl-4,4'-diyl group is more preferable.

In the formula (A3), Ar ¹² and Ar ¹³ are monovalent aromatic groups having 6 to 20 carbon atoms which may be independently substituted with Z ¹¹ , and Ar ¹² and Ar ¹³ are bonded to each other. Then, they may form a ring together with the nitrogen atom to which they are bonded. Further, each of Ar ¹² and Ar ¹³ may be the same as or different from each other. Z ¹¹ is a monovalent aliphatic hydrocarbon group or monovalent aromatic group having 1 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group or a cyano group, or a halogen atom, or a polymerizable group. ..

Examples of the monovalent aromatic group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, and a 3-phenanthryl group. Examples thereof include an aryl group such as a group, a 4-phenylyl group, a 9-phenanthryl group, a 2-biphenylyl group, a 3-biphenylyl group and a 4-biphenylyl group.

The monovalent aliphatic hydrocarbon may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. sec-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group , N-Dodecyl group and other alkyl groups with 1 to 20 carbon atoms; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1-butenyl group, 2-butenyl Examples thereof include an alkenyl group having 2 to 20 carbon atoms such as a group, a 3-butenyl group and a hexenyl group.

Examples of the polymerizable group include, but are not limited to, those represented by the following formulas.

In the formula, the broken line is the bond. ^Ra is a hydrogen atom or a methyl group. R ^b and R ^d are independently hydrogen atoms or alkyl groups having 1 to 6 carbon atoms, but methyl groups and ethyl groups are preferable. R ^c , R ^e, and R ^f are alkylene groups having 1 to 8 carbon atoms, which may independently contain a single bond or an oxygen atom, a sulfur atom, or a nitrogen atom. R ^g , R ^h and R ⁱ are independently hydrogen atoms or alkyl groups having 1 to 10 carbon atoms such as methyl group, ethyl group and n-propyl.

Y ^a and Y ^b are independently single bonds or divalent aromatic groups having 6 to 20 carbon atoms. The divalent aromatic group includes a 1,3-phenylene group, a 1,4-phenylene group, a 1,5-naphthylene group, a 1,6-naphthylene group, a 1,7-naphthylene group, and a 2,6-naphthylene group. Examples thereof include a 4,4'-biphenylylene group. Of these, a 1,3-phenylene group or a 1,4-phenylene group is preferable.

Ar ^a is a monovalent aromatic group having 6 to 20 carbon atoms which may have a substituent. Examples of the monovalent aromatic group include those similar to those described above.

As Z ¹¹ , a methyl group, an ethyl group, a polymerizable group represented by the following formula and the like are preferable.

(In the formula, the broken line is the bond.)

Examples of Ar ¹² and Ar ¹³ include phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2-ethylphenyl group, 3-ethylphenyl group, 4-ethylphenyl group and 2-vinyl. A phenyl group, a 3-vinylphenyl group, a 4-vinylphenyl group, a 1-naphthyl group, a 2-naphthyl group and the like are preferable.

The compound represented by the formula (A3) can be synthesized by a known method, or a commercially available product can also be used.

Other suitable examples of the tertiary arylamine compound include those represented by the following formula (A4), for example.

In the formula (A4), Ar ²¹ to Ar ²³ are independently divalent aromatic groups having 6 to 20 carbon atoms. As the divalent aromatic group, a divalent group derived from the compound represented by the above-mentioned formula (A3-1), (A3-3) or (A3-4) is preferable.

Of these, as Ar ²¹ to Ar ²³ , a 1,4-phenylene group, a biphenyl-4,4'-diyl group, a terphenyl-4,4''-diyl group and the like are preferable, and a 1,4-phenylene group. Alternatively, a biphenyl-4,4'-diyl group is more preferable.

In the formula (A4), Ar ²⁴ to Ar ²⁹ are monovalent aromatic groups having 6 to 20 carbon atoms which may be independently substituted with Z ²¹ . Examples of the monovalent aromatic group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, and a 3-phenanthryl group. Examples thereof include an aryl group such as a group, a 4-phenylyl group, a 9-phenanthryl group, a 2-biphenylyl group, a 3-biphenylyl group and a 4-biphenylyl group.

Z ²¹ is a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may be substituted with a halogen atom, a nitro group or a cyano group, or a halogen atom, a nitro group or a cyano group, −N (Ar ³⁰ ) ( Ar ³¹ ), or a polymerizable group. The monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group and n. -Butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n- Alkyl group having 1 to 20 carbon atoms such as decyl group, n-undecyl group, n-dodecyl group; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1 Examples thereof include an alkenyl group having 2 to 20 carbon atoms such as a butenyl group, a 2-butenyl group, a 3-butenyl group and a hexenyl group. Examples of the polymerizable group include those similar to those described above.

Ar ³⁰ and Ar ³¹ are each independently an aryl group having 6 to 20 carbon atoms which may be substituted with Z ²² , and they may be bonded to each other to form a ring with the nitrogen atom to which they are bonded. Good. Z ²² is a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom, a nitro group or a cyano group, or a halogen atom, a nitro group or a cyano group.

Examples of the aryl group having 6 to 20 carbon atoms and the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms are the same as those described above.

As Ar ³⁰ and Ar ³¹ , phenyl group, 1-naphthyl group, 2-naphthyl group, 1-biphenylyl group are preferable, and phenyl group, 1-biphenylyl group and the like are more preferable.

In particular, as -N (Ar ³⁰ ) (Ar ³¹ ), a diphenylamino group, a phenyl (4-biphenylyl) amino group, a bis (4-biphenylyl) amino group, an N-carbazolyl group and the like are preferable.

As Z ²¹ , an alkyl group having 1 to 10 carbon atoms, −N (Ar ³⁰ ) (Ar ³¹ ) and the like are preferable.

Examples of Ar ²⁴ to Ar ²⁹ include phenyl group, 4-biphenylyl group, 4-diphenylaminophenyl group, 4-phenyl (4-biphenylyl) aminophenyl group, bis (4-biphenylyl) aminophenyl group, and 4'-diphenylamino. -4-biphenylyl group, 4-phenyl (4-biphenylyl) amino-4-biphenylyl group, 4'-bis (4-biphenylyl) amino-4-biphenylyl group, N-carbazolylphenyl group, 4'-N- Carbazolyl-4-biphenylyl groups and the like are preferred.

The compound represented by the formula (A4) can be synthesized by a known method, or a commercially available product can also be used.

Other suitable examples of the tertiary arylamine compound include those represented by the following formula (A5), for example.

In formula (A5), Ar ⁴¹ and Ar ⁴² are independently phenyl groups, 1-naphthyl groups or 2-naphthyl groups, respectively. R ³⁰¹ and R ³⁰² are independently hydrogen atoms, diarylaminophenyl groups in which each aryl group is an aryl group having 6 to 20 carbon atoms, a chlorine atom, a bromine atom, and an iodine atom. Examples of the aryl group include those similar to those described in the description of R ¹ and R ^{2 in} the formula (A2). L ²¹ is a divalent linking group containing a propane-2,2-diyl group or a 1,1,1,1,3,3,3-hexafluoropropane-2,2-diyl group. x is an integer from 1 to 10.

The compound represented by the formula (A5) can be synthesized by a known method, or a commercially available product can also be used.

The tertiary arylamine compound is not limited to the above-mentioned compound as long as it has at least one nitrogen atom and all nitrogen atoms have a tertiary arylamine structure. Other tertiary arylamine compounds that can be used in the present invention include, for example, the arylamine compound described in International Publication No. 2005/094133, and the triarylamine partial structure and polymerizable property described in Japanese Patent No. 5287455. Examples thereof include a polymerizable compound having a group, a triarylamine compound described in Japanese Patent No. 5602191, a compound described in paragraph [0054] of Japanese Patent No. 6177771, and the like.

Preferred examples of the tertiary arylamine compound include, but are not limited to, those shown below.

[(B) Dopant]
The charge-transporting varnish of the present invention contains (B1) aryl sulfonic acid ester compound and (B2) halogenated tetracyanoquinodimethane or (B3) halogenated or cyanated benzoquinone as the dopant of the component (B).

[(B1) Aryl sulfonic acid ester compound]
The aryl sulfonic acid ester compound is not particularly limited as long as it has a sulfonic acid ester group bonded to the aromatic ring. In a preferred embodiment of the present invention, the molecular weight of the aryl sulfonic acid ester compound is preferably 100 or more, more preferably 200 or more, preferably 5,000 or less, more preferably 4,000 or less, still more preferably. It is 3,000 or less, more preferably 2,000 or less. In a preferred embodiment of the present invention, the number of sulfonic acid ester groups contained in the aryl sulfonic acid ester compound is preferably 2 or more, more preferably 3 or more, preferably 6 or less, and more preferably 5 or less. In a preferred embodiment of the invention, the aryl sulfonic acid ester compound preferably comprises a fluorine-substituted aromatic ring.

As the aryl sulfonic acid ester compound, those represented by the following formula (B1) or (B1') are preferable.

In the formulas (B1) and (B1'), A ¹ may have a substituent and is an m-valent hydrocarbon group having 6 to 20 carbon atoms including one or more aromatic rings, or the following formula ( Obtained by removing the m-valent group derived from the compound represented by B1a) or (B1b) (that is, m hydrogen atoms on the aromatic ring of the compound represented by the following formula (B1a) or (B1b). The group to be used).

(In the formula, W ¹ and W ² may independently have -O-, -S-, -S (O)-or -S (O ₂ )-, or -N. -, -Si-, -P- or -P (O)-)

The m-valent hydrocarbon group having 6 to 20 carbon atoms containing one or more aromatic rings is obtained by removing m hydrogen atoms from the hydrocarbon having 6 to 20 carbon atoms containing one or more aromatic rings. It is a group. Examples of the hydrocarbon containing one or more aromatic rings include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene and the like. Of these, as the m-valent hydrocarbon group, a group derived from benzene, biphenyl, or the like is preferable.

A part or all of the hydrogen atom of the hydrocarbon group may be further substituted with a substituent. Examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a hydroxy group, an amino group, a silanol group, a thiol group, a carboxy group, a sulfonic acid ester group, a phosphoric acid group and a phosphoric acid. It may be substituted with an ester group, an ester group, a thioester group, an amide group, a monovalent hydrocarbon group, an organooxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group, a sulfo group and the like.

Here, the monovalent hydrocarbon group may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl. Carbons such as groups, sec-butyl groups, tert-butyl groups, n-pentyl groups, cyclopentyl groups, n-hexyl groups, cyclohexyl groups, n-heptyl groups, n-octyl groups, n-nonyl groups and n-decyl groups. Alkyl groups of numbers 1-10; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, hexenyl An alkenyl group having 2 to 10 carbon atoms such as a group; an aryl group having 6 to 20 carbon atoms such as a phenyl group, a xsilyl group, a trill group, a 1-naphthyl group and a 2-naphthyl group; a carbon such as a benzyl group and a phenylethyl group. The number 7 to 20 aralkyl groups and the like can be mentioned.

Examples of the organooxy group include an alkoxy group, an alkenyloxy group, and an aryloxy group. Examples of the alkyl group, alkenyl group and aryl group contained therein include those similar to those described above.

Examples of the organoamino group include methylamino group, ethylamino group, propylamino group, butylamino group, pentylamino group, hexylamino group, cyclohexylamino group, heptylamino group, octylamino group, nonylamino group, decylamino group and dodecyl. Alkylamino group having 1 to 12 carbon atoms such as amino group; dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, dipentylamino group, dihexylamino group, dicyclohexylamino group, diheptylamino group, dioctylamino group , Dialkylamino group in which each alkyl group such as dinonylamino group and didecylamino group is an alkyl group having 1 to 12 carbon atoms; morpholino group and the like can be mentioned.

Examples of the organosilyl group include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a tripentylsilyl group, a trihexylsilyl group, a pentyldimethylsilyl group, a hexyldimethylsilyl group, an octyldimethylsilyl group and a decyldimethyl group. Examples thereof include a trialkylsilyl group in which each alkyl group such as a silyl group is an alkyl group having 1 to 10 carbon atoms.

Examples of the organothio group include alkylthio groups having 1 to 12 carbon atoms such as methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, heptylthio group, octylthio group, nonylthio group, decylthio group and dodecylthio group. Be done.

Examples of the acyl group include acyl groups having 1 to 10 carbon atoms such as formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group and benzoyl group.

The carbon number of the monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group and acyl group is preferably 1 to 8.

Among each of these substituents, a fluorine atom, a sulfonic acid group, an alkyl group, an organooxy group, and an organosilyl group are more preferable.

In formula (B1), A ² is -O-, -S- or -NH-. Of these, —O— is preferable because it is easy to synthesize.

In formula (B1), A ³ is a (n + 1) -valent aromatic group having 6 to 20 carbon atoms. The aromatic group is a group obtained by removing (n + 1) hydrogen atoms on an aromatic ring from an aromatic compound having 6 to 20 carbon atoms. In the present invention, the aromatic compound means an aromatic hydrocarbon and an aromatic heterocyclic compound. Examples of the aromatic compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene and the like. Among these, the aromatic group represented by A ³ is a group derived from naphthalene or anthracene. Is preferable.

In formulas (B1) and (B1'), X ¹ is an alkylene group having 2 to 5 carbon atoms, and the alkylene group is formed between the carbon atoms (carbon-carbon bond) of −O—, −. An S- or a carbonyl group may be interposed, and a part or all of the hydrogen atom may be further substituted with an alkyl group having 1 to 20 carbon atoms. As X ¹ , an ethylene group, a trimethylene group, a methyleneoxymethylene group, a methylenethiomethylene group and the like are preferable, and a part or all of the hydrogen atoms of these groups are further substituted with an alkyl group having 1 to 20 carbon atoms. You may. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group and n-hexyl group. , Cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, bicyclohexyl group and the like.

In formulas (B1) and (B1'), X ² is a single bond, -O-, -S- or -NR-. R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. As the monovalent hydrocarbon group, an alkyl group such as a methyl group, an ethyl group or an n-propyl group is preferable. As X ² , a single bond, —O— or —S— is preferable, and a single bond or —O— is more preferable.

Wherein (B1) and (B1 '), X ³ is a monovalent hydrocarbon group substituted by 1 carbon atoms which may be 1-20. The monovalent hydrocarbon group may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and sec. -Butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, Alkyl groups having 1 to 20 carbon atoms such as n-dodecyl group and bicyclohexyl group; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1-butenyl group, Alkenyl groups having 2 to 20 carbon atoms such as 2-butenyl group, 3-butenyl group, hexenyl group; phenyl group, xsilyl group, trill group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group Group, 9-anthril group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group and the like Examples thereof include an aryl group of 6 to 20; an aralkyl group having 7 to 20 carbon atoms such as a benzyl group, a phenylethyl group and a phenylcyclohexyl group. Further, a part or all of the hydrogen atoms of the monovalent hydrocarbon group may be further substituted with a substituent. Examples of the substituent include those similar to those described in the description of A ¹ . As X ³ , an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms is preferable.

In the formulas (B1) and (B1'), m is an integer satisfying 1 ≦ m ≦ 4, but 2 is preferable. n is an integer satisfying 1 ≦ n ≦ 4, but 2 is preferable.

Since the aryl sulfonic acid ester compounds represented by the formulas (B1) and (B1') are highly soluble in a wide range of solvents including low protic solvents, the physical properties of the solution are prepared using a wide variety of solvents. It is possible to do so and the coating characteristics are high. Therefore, it is preferable to apply in the state of a sulfonic acid ester and generate sulfonic acid when the coating film is dried or fired. The temperature at which sulfonic acid is generated from the sulfonic acid ester is preferably 40 to 260 ° C. because it is stable at room temperature and preferably equal to or lower than the firing temperature. Further, considering the high stability in the varnish and the ease of desorption during firing, 80 to 230 ° C. is preferable, and 120 to 180 ° C. is more preferable.

As the aryl sulfonic acid ester compound represented by the formula (B1), those represented by any of the following formulas (B1-1) to (B1-3) are preferable.

In formula (B1-1), A ¹¹ is an m-valent group derived from perfluorobiphenyl (that is, a group obtained by removing m fluorine atoms from perfluorobiphenyl). A ¹² is —O— or —S—, but —O— is preferred. A ¹³ is a (n + 1) -valent group derived from naphthalene or anthracene (that is, a group obtained by removing (n + 1) hydrogen atoms from naphthalene or anthracene), but a group derived from naphthalene is preferable. ..

In the formula (B1-1), R ^s1 to R ^s4 are independently hydrogen atoms or linear or branched alkyl groups having 1 to 6 carbon atoms, and R ^s5 may be substituted. It is a good monovalent hydrocarbon group having 2 to 20 carbon atoms.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a tert-butyl group. , N-Hexyl group and the like. Of these, 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 group, n-propyl group, isopropyl group, n-butyl group and isobutyl. Examples include an alkyl group such as a group, a sec-butyl group and a tert-butyl group; and an aryl group such as a phenyl group, a naphthyl group and a phenanthryl group.

Of R ^s1 to R ^s4 , it is preferable that R ^s1 or R ^s3 is a linear alkyl group having 1 to 3 carbon atoms and the rest are hydrogen atoms. Further, it is preferable that R ^s1 is a linear alkyl group having 1 to 3 carbon atoms and R ^s2 to R ^s4 are hydrogen atoms. As the linear alkyl group having 1 to 3 carbon atoms, a methyl group is preferable. Further, as R ^s5 , a linear alkyl group or a phenyl group having 2 to 4 carbon atoms is preferable.

In the formula (B1-1), 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 (B1-2), A ¹⁴ is an m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings which may be substituted. The hydrocarbon group is a group obtained by removing m hydrogen atoms from a hydrocarbon having one or more aromatic rings and having 6 to 20 carbon atoms. Examples of the hydrocarbon include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, phenanthrene and the like.

In addition, a part or all of the hydrogen atom of the hydrocarbon group may be further substituted with a substituent, and such substituents include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and a nitro. 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, as A ¹⁴ , a group derived from benzene, biphenyl, or the like is preferable.

In formula (B1-2), A ¹⁵ is —O— or —S—, but —O— is preferred.

In the formula (B1-2), A ¹⁶ is a (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. The aromatic hydrocarbon group is a group obtained by removing (n + 1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene and the like. Of these, as A ¹⁶ , a group derived from naphthalene or anthracene is preferable, and a group derived from naphthalene is more preferable.

In formula (B1-2), R ^s6 and R ^s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group. R ^s8 is a linear or branched monovalent aliphatic hydrocarbon group. However, the total number of carbon atoms 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, and more preferably 10 or less.

Specific examples of the linear or branched monovalent aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and tert-. Alkyl group having 1 to 20 carbon atoms such as butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, decyl group; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1- Examples thereof include an alkenyl group having 2 to 20 carbon atoms such as a methyl-2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group and a hexenyl group.

A hydrogen atom is preferable as R ^s6 , and an alkyl group having 1 to 6 carbon atoms is preferable as R ^s7 and R ^s8 . In this case, R ^s7 and R ^s8 may be the same or different.

In the formula (B1-2), 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 the formula (B1-3), R ^s9 to R ^s13 are independently hydrogen atom, nitro group, cyano group, halogen atom, alkyl group having 1 to 10 carbon atoms, and alkyl halide group having 1 to 10 carbon atoms, respectively. , Or 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 group, ethyl group, n-propyl group, isopropyl group, n-butyl group and isobutyl. Group, sec-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group and the like. Be done.

The alkyl halide group having 1 to 10 carbon atoms is not particularly limited as long as it is a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms are substituted with halogen atoms. The alkyl halide group may be linear, branched or cyclic, and specific examples thereof include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, 1,1,2,2, 2-Pentafluoroethyl group, 3,3,3-trifluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, 1,1,2,2,3,3,3-heptafluoropropyl Group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 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 a part or all of the hydrogen atoms of the alkenyl group having 2 to 10 carbon atoms are substituted with halogen atoms. Specific examples thereof include a perfluorovinyl group, a perfluoro-1-propenyl group, a perfluoro-2-propenyl group, a perfluoro-1-butenyl group, a perfluoro-2-butenyl group, and a perfluoro-3-butenyl group. And so on.

Of these, as R ^s9 , a nitro group, a cyano group, an alkyl halide group having 1 to 10 carbon atoms, an alkenyl halide group having 2 to 10 carbon atoms and the like are preferable, and a nitro group, a cyano group and 1 to 10 carbon atoms are preferable. The alkyl halide group of 4 and the alkenyl halide group having 2 to 4 carbon atoms are more preferable, and the nitro group, the cyano group, the trifluoromethyl group, the perfluoropropenyl group and the like are even more preferable. Further, as R ^s10 to R ^s13 , a halogen atom is preferable, and a fluorine atom is more preferable.

In formula (B1-3), A ¹⁷ is -O-, -S- or -NH-, but -O- is preferable.

In the formula (B1-3), A ¹⁸ is an (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms. The aromatic hydrocarbon group is a group obtained by removing (n + 1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, pyrene and the like. Of these, as A ¹⁸ , a group derived from naphthalene or anthracene is preferable, and a group derived from naphthalene is more preferable.

In the formula (B1-3), R ^s14 to R ^s17 are independently hydrogen atoms or linear or branched monovalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms. The monovalent aliphatic hydrocarbon group may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. , Se-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl Alkyl group having 1 to 20 carbon atoms such as group, n-dodecyl group; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1-butenyl group, 2- Examples thereof include an alkenyl group having 2 to 20 carbon atoms such as a butenyl group, a 3-butenyl group and a hexenyl group. Of these, an alkyl group having 1 to 20 carbon atoms is preferable, an alkyl group having 1 to 10 carbon atoms is more preferable, and an alkyl group having 1 to 8 carbon atoms is even more preferable.

In formula (B1-3), R ^s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or −OR ^s19 . R ^s19 is a monovalent hydrocarbon group having 2 to 20 carbon atoms which may be substituted.

^Examples of the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by R ^s18 include those similar to those described in the description of R ^s14 to R ^s17 . 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. Is even more preferable.

The monovalent hydrocarbon group having 2 to 20 carbon atoms represented by R ^s19 includes an aryl group such as a phenyl group, a naphthyl group and a phenanthryl group in addition to the above-mentioned monovalent aliphatic hydrocarbon groups other than the methyl group. And so on. Of these, as R ^s19 , a linear alkyl group or a phenyl group having 2 to 4 carbon atoms is preferable. Examples of the substituent that the 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.

In the formula (B1-3), n is an integer satisfying 1 ≦ n ≦ 4, but 2 is preferable.

As the aryl sulfonic acid ester compound represented by the formula (B1-3), those represented by the following formula (B1-3-1) or (B1-3-2) are particularly preferable.

In formulas (B1-3-1) and (B1--3-2), A ¹⁷ , A ¹⁸ , R ^s9 to R ^s17 , R ^s19 and n are the same as described above. R ^s20 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, and specific examples thereof include those described in the description of R ^s18 .

In the aryl sulfonic acid ester compound represented by the formula (B1-3-1), among R ^s14 to R ^s17 , R ^s14 or R ^s16 is a linear alkyl group having 1 to 3 carbon atoms, and the rest is hydrogen. It is preferably an atom. Further, it is preferable that R ^s14 is a linear alkyl group having 1 to 3 carbon atoms and R ^s15 to R ^s17 are hydrogen atoms. As the linear alkyl group having 1 to 3 carbon atoms, a methyl group is preferable. Further, as R ^s19 , a linear alkyl group or a phenyl group having 2 to 4 carbon atoms is preferable.

In the aryl sulfonic acid ester compound represented by the formula (B1-3-2), the total number of carbon atoms of R ^s14 , R ^s16 and R ^s20 is preferably 6 or more. The upper limit of the total number of carbon atoms of R ^s14 , R ^s16 and R ^s20 is preferably 20 or less, and more preferably 10 or less. In this case, R ^s14 is preferably a hydrogen atom, and R ^s16 and R ^s20 are preferably an alkyl group having 1 to 6 carbon atoms. Further, R ^s16 and R ^s20 may be the same as or different from each other.

The aryl sulfonic acid ester compound represented by the formula (B1) may be used alone or in combination of two or more.

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

The aryl sulfonic acid ester compound represented by the formula (B1) is obtained by reacting the sulfonate compound represented by the formula (B1A) with a halogenating agent, for example, as shown in the following scheme A, to form the following formula (B1). The sulfonyl halide compound represented by B1B) is synthesized (hereinafter, also referred to as step 1), and the sulfonyl halide compound is reacted with the compound represented by the formula (B1C) (hereinafter, also referred to as step 2). Can be synthesized with.

(In the formula, A ¹ to A ³ , X ¹ to X ³ , m and n are the same as described above. M ⁺ is a monovalent cation such as sodium ion, potassium ion, pyridinium ion, quaternary ammonium ion and the like. .Hal is a halogen atom such as a chlorine atom and a bromine atom.)

The sulfonate compound represented by the formula (B1A) can be synthesized according to a known method.

Examples of the halogenating agent used in step 1 include halogenating agents such as thionyl chloride, oxalyl chloride, phosphorus oxychloride, and phosphorus (V) chloride, but thionyl chloride is preferable. The amount of the halogenating agent used is not limited as long as it is 1 times or more the molar amount of the sulfonate compound, but it is preferably used in an amount of 2 to 10 times the mass ratio of the sulfonate compound.

The reaction solvent used in step 1 is preferably a solvent that does not react with the halogenating agent, and examples thereof include chloroform, dichloroethane, carbon tetrachloride, hexane, and heptane. Further, the reaction can be carried out without a solvent, and in this case, it is preferable to use a halogenating agent in an amount equal to or more than a uniform solution at the end of the reaction. Further, in order to promote the reaction, a catalyst such as N, N-dimethylformamide may be used. The reaction temperature can be about 0 to 150 ° C., but is preferably 20 to 100 ° C. and below the boiling point of the halogenating agent used. After completion of the reaction, the crude product obtained by concentration under reduced pressure or the like is generally used in the next step.

Examples of the compound represented by the formula (B1C) include glycols such as propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, ethylene glycol monobutyl ether, and ethylene glycol monohexyl ether. Ethers; alcohols such as 2-ethyl-1-hexanol, 2-butyl-1-octanol, 1-octanol, 3-nonanol and the like can be mentioned.

In step 2, a base may be used in combination. Examples of the base that can be used include sodium hydride, pyridine, triethylamine, diisopropylethylamine and the like, but sodium hydride, pyridine and triethylamine are preferable. The amount of the base used is preferably 1 times the molar amount to the amount of the solvent with respect to the sulfonyl halide compound.

As the reaction solvent used in step 2, various organic solvents can be used, but tetrahydrofuran, dichloroethane, chloroform and pyridine are preferable. The reaction temperature is not particularly limited, but 0 to 80 ° C. is preferable. After completion of the reaction, a pure aryl sulfonic acid ester compound can be obtained by post-treatment and purification using conventional methods such as concentration under reduced pressure, liquid separation extraction, washing with water, reprecipitation, recrystallization, and chromatography. It is also possible to obtain a high-purity sulfonic acid compound by subjecting the obtained pure aryl sulfonic acid ester compound to heat treatment or the like.

Further, the aryl sulfonic acid ester compound represented by the formula (B1) can also be synthesized from the sulfonic acid compound represented by the formula (B1D) as shown in the following scheme B. In the scheme B below, the halogenating agent used in the first and second stage reactions, the compound represented by the formula (B1C), the reaction solvent and other components are the same as in steps 1 and 2 in the scheme A. Can be used.

(In the formula, A ¹ to A ³ , X ¹ to X ³ , Hal, m and n are the same as above.)

The sulfonic acid compound represented by the formula (B1D) can be synthesized according to a known method.

The aryl sulfonic acid ester compound represented by the formula (B1') can be synthesized according to a conventionally known method, for example, the method described in Japanese Patent No. 5136795.

[(B2) Halogenated Tetracyanoquinodimethane]
As the halogenated tetracyanoquinodimethane, those represented by the following formula (B2) are preferable.

In the formula ( ^B2-1 ), R ^q1 to R ^q4 are independently hydrogen atoms or halogen atoms, but at least one is a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable. ^Further , at least two of R ^q1 to R ^q4 are preferably halogen atoms, at least three are more preferably halogen atoms, and most preferably all are halogen atoms.

Examples of the tetracyanoquinodimethane derivative include 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 2-fluoro-7,7,8,8-tetracyanoquinodimethane, 2,5-difluoro. -7,7,8,8-Tetracyanoquinodimethane, Tetrafluoro-7,7,8,8-Tetracyanoquinodimethane (F4TCNQ), Tetrachloro-7,7,8,8-Tetracyanoquinodimethane Methane, 2-fluoro-7,7,8,8-tetracyanoquinodimethane, 2-chloro-7,7,8,8-tetracyanoquinodimethane, 2,5-difluoro-7,7,8, Examples thereof include 8-tetracyanoquinodimethane, 2,5-dichloro-7,7,8,8-tetracyanoquinodimethane. Of these, F4TCNQ is preferable.

[(B3) Halogenated or cyanated benzoquinone]
As the halogenated or cyanated benzoquinone, those represented by the formula (B3) are preferable.

In the formula (B2-2), R ^q5 to R ^q8 are independently hydrogen atoms, halogen atoms or cyano groups, but at least one is a halogen atom or cyano group. Examples of the halogen atom include the same as those described above, and a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable. Further, it is preferable that at least two of R ^q5 to R ^q8 are halogen atoms or cyano groups, more preferably at least three are halogen atoms or cyano groups, and even more preferably all of them are halogen atoms or cyano groups. preferable.

Specifically, as halogenated or cyanated benzoquinone, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), tetrachloro-1,4-benzoquinone (chloranil), trifluoro-1, Examples thereof include 4-benzoquinone, tetrafluoro-1,4-benzoquinone, tetrabromo-1,4-benzoquinone, tetracyano-1,4-benzoquinone and the like. Of these, 2,3-dichloro-5,6-dicyano-p-benzoquinone, trifluorobenzoquinone, tetrafluorobenzoquinone, and tetracyanobenzoquinone are preferable, and DDQ, chloranil, tetrafluoro-1,4-benzoquinone, and tetracyano-1 are preferable. , 4-Benzoquinone is more preferred, and DDQ is even more preferred.

In the dopant of the component (B), the content of the (B1) aryl sulfonic acid ester compound is usually 0 in molar ratio with respect to (B2) tetracyanoquinodimethane halogenated or (B3) halogenated or benzoquinone cyanated. The amount is about .01 to 50, preferably about 0.1 to 20, and more preferably about 1.0 to 10. The total content of the dopant of the component (B) is such that the ratio (D / H) of the content of the dopant to the charge-transporting organic compound is usually about 0.01 to 50 in terms of molar ratio. It is preferably an amount of about 0.1 to 10, and more preferably an amount of about 1.0 to 5.0.

In addition, (B2) halogenated tetracyanoquinodimethane can be used alone or in combination of two or more, and (B3) halogenated or cyanated benzoquinone can be used alone or in combination of two or more. be able to. Further, (B2) halogenated tetracyanoquinodimethane and (B3) halogenated or cyanated benzoquinone can be used in combination.

[(C) Organic solvent]
The organic solvent (C) is not particularly limited as long as it can dissolve or disperse each of the above-mentioned components and each of the optional components described below, but a low-polarity solvent may be used because of its excellent process compatibility. preferable. In the present invention, a low-polarity solvent is defined as a solvent having a relative permittivity of less than 7 at a frequency of 100 kHz, and a high-polarity solvent is defined as a solvent having a relative permittivity of 7 or more at a frequency of 100 kHz.

Examples of the low polar solvent include chlorine-based solvents such as chloroform and chlorobenzene; aromatic hydrocarbon-based solvents such as toluene, xylene, tetraline, cyclohexylbenzene and decylbenzene; 1-octanol, 1-nonanol, 1-decanol and the like. Alibo alcohol solvents; ethers 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, bis (2-ethylhexyl) phthalate, dimethyl phthalate, diisopropyl malate, dibutyl maleate, dibutyl oxalate, hexyl acetate, propylene glycol monomethyl ether Examples thereof include ester solvents such as acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate.

Examples of the highly polar solvent include amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylisobutylamide, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone. System solvent: Ketone solvent such as ethyl methyl ketone, isophorone, cyclohexanone; Cyano solvent such as acetonitrile and 3-methoxypropionitrile; Ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, Polyhydric alcohol solvents such as 2,3-butanediol; diethylene glycol monomethyl ether, diethylene glycol monophenyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, benzyl alcohol, 2-phenoxyethanol, 2-benzyl Monohydric alcohol solvents other than aliphatic alcohols such as oxyethanol, 3-phenoxybenzyl alcohol and tetrahydrofurfuryl alcohol; sulfoxide solvents such as dimethyl sulfoxide and the like can be mentioned.

(C) The amount of the organic solvent used is such that the solid content concentration in the varnish of the present invention is usually 0.1 to 20% by mass from the viewpoint of ensuring a sufficient film thickness while suppressing the precipitation of the charge-transporting organic compound. The amount is preferably 0.5 to 10% by mass. The solid content means a component other than the solvent among the components contained in the varnish. The solvent may be used alone or in combination of two or more.

[Other ingredients]
The charge-transporting varnish of the present invention may further contain an organic silane compound for the purpose of adjusting the film physical characteristics of the obtained charge-transporting thin film. Examples of the organic silane compound include a dialkoxysilane compound, a trialkoxysilane compound, and a tetraalkoxysilane compound. In particular, as the organic silane compound, a dialkoxysilane compound or a trialkoxysilane compound is preferable, and a trialkoxysilane compound is more preferable. The organic silane compound may be used alone or in combination of two or more.

When the varnish of the present invention contains an organic silane compound, the content thereof is usually about 0.1 to 50% by mass in the solid content, but the flatness of the obtained thin film is improved and the decrease in charge transportability is suppressed. In consideration of such a balance, it is preferably about 0.5 to 40% by mass, more preferably about 0.8 to 30% by mass, and even more preferably about 1 to 20% by mass.

The charge-transporting varnish of the present invention may contain an amine compound from the viewpoint of dissolving a charge-transporting organic compound or a dopant in a solvent to obtain a highly uniform varnish, and the content thereof is usually 0 in the solid content. It is about 1 to 50% by mass.

The method for preparing the charge-transporting varnish is not particularly limited, and examples thereof include a method of adding a charge-transporting organic compound and a dopant and, if necessary, other components to the organic solvent in any order or at the same time. When there are a plurality of organic solvents, each component may be dissolved in one solvent sequentially or simultaneously, and another solvent may be added thereto. Each component may be sequentially or simultaneously dissolved in a mixed solvent of a plurality of organic solvents. It may be dissolved.

From the viewpoint of obtaining a thin film having higher flatness with good reproducibility, it is desirable that the charge transporting varnish of the present invention is filtered using a submicrometer order filter or the like after dissolving each component in an organic solvent.

The viscosity of the charge-transporting varnish of the present invention is usually 1 to 50 mPa · s at 25 ° C. The surface tension of the charge-transporting varnish of the present invention is usually 20 to 50 mN / m at 25 ° C. The viscosity is a value measured by a TVE-25 type viscometer manufactured by Toki Sangyo Co., Ltd. The surface tension is a value measured by an automatic surface tension meter CBVP-Z manufactured by Kyowa Interface Science Co., Ltd. The viscosity and surface tension of the varnish can be adjusted by changing the types of solvents described above, their ratios, the solid content concentration, and the like in consideration of various factors such as a desired film thickness.

[Charge transport thin film]
The charge-transporting thin film of the present invention can be formed by applying the charge-transporting varnish of the present invention on a substrate and firing it.

Examples of the varnish coating method include, but are not limited to, the dip method, spin coating method, transfer printing method, roll coating method, brush coating, inkjet method, spray method, slit coating method, and the like. It is preferable to adjust the viscosity and surface tension of the varnish according to the coating method.

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 charge-transporting property can be obtained not only in the air atmosphere but also in an inert gas such as nitrogen or in a vacuum. However, usually, by firing the varnish in an air atmosphere, a thin film having higher charge transportability can be obtained with good reproducibility.

The firing temperature is usually set appropriately within the range of about 100 to 260 ° C. in consideration of the intended use of the obtained thin film, the degree of charge transportability applied to the obtained thin film, the type of solvent, the boiling point, and the like. At the time of firing, a temperature change of two or more steps may be applied for the purpose of exhibiting higher uniform film forming property or allowing the reaction to proceed on the substrate, and heating may be performed by, for example, a hot plate or the like. It may be carried out using an appropriate device such as an oven.

The film thickness of the charge transporting thin film is not particularly limited, but when it is used as a functional layer between the anode and the light emitting layer such as a hole injection layer, a hole transport layer or a hole injection transport layer of an organic EL element, 5 It is preferably about 300 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 liquid on the substrate at the time of coating.

The charge-transporting thin film of the present invention can be formed by the method described above, but by using the charge-transporting varnish of the present invention, the charge-transporting thin film can be suitably formed in the partition wall of the substrate with a partition wall.

The substrate with a partition wall is not particularly limited as long as it is a substrate on which a predetermined pattern is formed by a known photolithography method or the like. Normally, there are a plurality of openings defined by the partition wall on the substrate. Usually, the size of the opening is 100 to 210 μm on the long side, 40 μm × 100 μm on the short side, and the bank taper angle is 20 to 80 °. The material of the substrate is not particularly limited, but is a transparent electrode material typified by indium tin oxide (ITO) and indium zinc oxide (IZO) used as an anode material of an electronic element; aluminum, gold, Metal anode materials composed of metals typified by silver, copper, indium, etc. or alloys thereof; polymer anode materials such as polythiophene derivatives and polyaniline derivatives having high charge transport properties, etc., are subjected to flattening treatment. Is preferable.

The charge transporting varnish of the present invention is applied to the inside of the partition wall of the substrate with a partition wall by an inkjet method, then depressurized, and further heated if necessary to remove the solvent from the charge transporting varnish coated inside the partition wall. A charge-transporting thin film can be produced to produce a substrate with a charge-transporting thin film, and further, by laminating other functional films on the charge-transporting thin film, an electronic element such as an organic EL element can be formed. Can be manufactured. At this time, the atmosphere at the time of coating with the inkjet is not particularly limited, and may be any of an air atmosphere, an atmosphere of an inert gas such as nitrogen, and a reduced pressure.

The degree of decompression (vacuum degree) at the time of depressurization is not particularly limited as long as the solvent of the varnish evaporates, but is usually 1,000 Pa or less, preferably 100 Pa or less, more preferably 50 Pa or less, still more preferably 25 Pa or less, and further. It is preferably 10 Pa or less. The depressurization time is also not particularly limited as long as the solvent evaporates, but is usually about 0.1 to 60 minutes, preferably about 1 to 30 minutes. The conditions for firing (heating) are the same as the above-mentioned conditions.

According to the method described above, the creeping up of the varnish can be effectively suppressed in the partition wall. Specifically, the pile-up index described later is usually a high value of 83% or more, preferably 86% or more, more preferably 89% or more, even more preferably 92% or more, still more preferably 95% or more. Up can be suppressed. The pile-up index is when the partition wall (bank) width is A (μm) and the film thickness range of + 10% from the film thickness of the charge-transporting thin film at the center of the partition wall (bank) is B (μm). It can be calculated by the formula (B / A) × 100 (%).

[Organic EL element]
The organic EL device of the present invention has a pair of electrodes, and has a functional layer made of the charge-transporting thin film of the present invention between these electrodes.

Typical configurations of the organic EL element include, but are not limited to, the following (a) to (f). In the following configuration, if necessary, an electron block layer or the like may be provided between the light emitting layer and the anode, and a hole block layer or the like may be provided between the light emitting layer and the cathode. Further, the hole injection layer, the hole transport layer or the hole injection transport layer may have a function as an electron block layer or the like, and the electron injection layer, the electron transport layer or the electron injection transport layer may serve as a hole block layer or the like. It may also have the functions of. Further, if necessary, an arbitrary functional layer can be provided between the layers.
(A) Electron / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (b) anode / hole injection layer / hole transport layer / light emitting layer / electron injection transport layer / Cathode (c) anode / hole injection transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (d) anode / hole injection transport layer / light emitting layer / electron injection transport layer / cathode (e) anode / positive Hole injection layer / hole transport layer / light emitting layer / cathode (f) Electron / hole injection transport layer / light emitting layer / cathode

The "hole injection layer", "hole transport layer" and "hole injection transport layer" are layers formed between the light emitting layer and the anode, and transport holes from the anode to the light emitting layer. It has a function. When only one layer of hole transporting material is provided between the light emitting layer and the anode, it is a "hole injection transport layer", and a layer of hole transporting material between the light emitting layer and the anode. When two or more layers are provided, the layer close to the anode is the "hole injection layer", and the other layers are the "hole transport layers". In particular, as the hole injection (transport) layer, a thin film having excellent not only hole acceptability from the anode but also hole injection property into the hole transport (emission) layer is used.

The "electron injection layer", "electron transport layer" and "electron transport layer" are layers formed between the light emitting layer and the cathode and have a function of transporting electrons from the cathode to the light emitting layer. Is. When only one layer of electron transporting material is provided between the light emitting layer and the cathode, it is an "electron injection transporting layer", and two layers of electron transporting material are provided between the light emitting layer and the cathode. When the above is 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 the recombination of electrons and holes and confining the excitons in the light emitting layer, and the dopant material efficiently emits excitons obtained by the recombination. Has a function. In the case of a phosphorescent device, the host material mainly has a function of confining excitons generated by the dopant in the light emitting layer.

The charge transporting thin film of the present invention can be suitably used as a functional layer provided between the anode and the light emitting layer in an organic EL device, and can be used as a hole injection layer, a hole transport layer, or a hole injection transport layer. It can be used more preferably, and can be used even more preferably as a hole injection layer.

The materials and manufacturing methods used when manufacturing an organic EL device using the charge transporting varnish of the present invention include, but are not limited to, the following.

An example of a method for producing an organic EL device having a hole injection layer made of a charge transporting thin film obtained from the charge transporting varnish of the present invention is as follows. It is preferable that the electrode is preliminarily subjected to surface treatment such as cleaning with alcohol, pure water or the like, UV ozone treatment, oxygen-plasma treatment or the like within a range that does not adversely affect the electrode.

A hole injection layer is formed on the anode substrate by the above method using the charge transporting varnish of the present invention. 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 vapor-deposited. Alternatively, instead of forming the hole transport layer and the light emitting layer by vapor deposition in the method, a composition for forming a hole transport layer containing a hole transport polymer and a composition for forming a light emitting layer containing a light emitting polymer are used. These layers are formed by a wet process using. If necessary, an electron block layer may be provided between the light emitting layer and the hole transport layer.

Examples of the anode material include transparent electrodes typified by ITO and IZO, metals typified by aluminum, and metal anodes composed of alloys thereof, and those subjected to flattening treatment are preferable. Polythiophene derivatives and polyaniline derivatives having high charge transport properties can also be used. Examples of other metals constituting the metal anode include, but are not limited to, gold, silver, copper, indium, and alloys thereof.

Examples of the material for forming the hole transport layer include (triphenylamine) dimer derivative, [(triphenylamine) dimer] spirodimer, and 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''- Triarylamines such as tris [1-naphthyl (phenyl) amino] triphenylamine (1-TNATA), 5,5''-bis- {4- [bis (4-methylphenyl) amino] phenyl} -2 , 2': 5', 2''-oligothiophenes such as turthiophene (BMA-3T) and the like can be mentioned.

Examples of the material forming the light emitting layer include a metal complex such as an aluminum complex of 8-hydroxyquinoline, a metal complex of 10-hydroxybenzo [h] quinoline, a bisstyrylbenzene derivative, a bisstyryl arylene derivative, and (2-hydroxyphenyl). Low molecular weight luminescent materials such as benzothiazole metal complexes and silol derivatives; poly (p-phenylene vinylene), poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene], poly (3- Alkylthiophene), a system in which a light emitting material and an electron transfer material are mixed with a polymer compound such as polyvinylcarbazole, and the like, but are not limited thereto.

When the light emitting layer is formed by vapor deposition, it may be co-deposited with a light emitting dopant, and the light emitting dopant may be a metal such as tris (2-phenylpyridine) iridium (III) (Ir (ppy) ₃ ). Examples thereof include, but are not limited to, a complex, a naphthacene derivative such as rubrene, a quinacridone derivative, and a condensed polycyclic aromatic ring such as perylene.

Examples of the material for forming the electron transport layer / whole block layer include, but are not limited to, an oxydiazole derivative, a triazole derivative, a phenanthroline derivative, a phenylquinoxaline derivative, a benzimidazole derivative, and a pyrimidine derivative.

Examples of the material forming the electron injection layer include metal oxides such as lithium oxide (Li ₂ O), magnesium oxide (Mg O), and alumina (Al ₂ O ₃ ), lithium fluoride (LiF), and sodium fluoride (NaF). ), But is not limited to these.

Examples of the cathode material include, but are not limited to, aluminum, magnesium-silver alloy, aluminum-lithium alloy, and the like.

Examples of the material for forming the electron block 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-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 can be mentioned.

Examples of the luminescent polymer include polyfluorene derivatives such as poly (9,9-dialkylfluorene) (PDAF) and poly (2-methoxy-5- (2'-ethylhexoxy) -1,4-phenylene vinylene) (MEH). -PPV) and other polyphenylene vinylene derivatives, poly (3-alkylthiophene) (PAT) and other polythiophene derivatives, polyvinylcarbazole (PVCz) and the like can be mentioned.

The materials forming the anode and cathode and the layer formed between them differ depending on whether the element having the bottom emission structure or the top emission structure is manufactured. Therefore, the material is appropriately selected in consideration of this point. ..

Normally, in an element having a bottom emission structure, a transparent anode is used on the substrate side to extract light from the substrate side, whereas in an element having a top emission structure, a reflective anode made of metal is used and the direction is opposite to that of the substrate. Light is extracted from a certain transparent electrode (cathode) side. Therefore, for example, regarding the anode material, a transparent anode such as ITO is used when manufacturing an element having a bottom emission structure, and a reflective anode such as Al / Nd is used when manufacturing an element having a top emission structure.

The organic EL device of the present invention may be sealed together with a water catching agent or the like, if necessary, in accordance with a conventional method in order to prevent deterioration of characteristics.

As described above, the charge transporting thin film of the present invention can be used as a functional layer of an organic EL element, but in addition, an organic photoelectric conversion element, an organic thin film solar cell, an organic perovskite photoelectric conversion element, an organic integrated circuit, and an organic Electric field effect transistors, organic thin films, organic light emitting transistors, organic optical testers, organic photoreceivers, organic electric field extinguishing devices, light emitting electronic chemical batteries, quantum dot light emitting diodes, quantum lasers, organic laser diodes, organic Plasmon light emitting devices, etc. It can also be used as a functional layer of an electronic device.

Hereinafter, the present invention will be described in more detail with reference to synthetic examples, production examples, examples and comparative examples, but the present invention is not limited to the following examples.

The equipment used is as follows.
(1) MALDI-TOF-MS: Bruker's autoflex III smart beam
(2) ^{1 1} H-NMR: JNM-ECP300 FT NMR SYSTEM manufactured by JEOL Ltd.
(3) Substrate cleaning: Substrate cleaning equipment manufactured by Choshu Sangyo Co., Ltd. (decompression plasma method)
(4) Varnish application: Spin coater MS-A100 manufactured by Mikasa Co., Ltd.
(5) Film thickness measurement and surface shape measurement: Fine shape measuring machine surf coder ET-4000A manufactured by Kosaka Laboratory Co., Ltd.
(6) Manufacture of element: Multi-function vapor deposition equipment system C-E2L1G1-N manufactured by Choshu Sangyo Co., Ltd.
(7) Measurement of element current density: Multi-channel IVL measuring device manufactured by EHC Co., Ltd. (8) Inkjet device: Dedicated driver WAVE BUILDER (model number: PIJD-1) manufactured by Cluster Technology Co., Ltd., observation device with camera inkjetlado, automatic stage Inkjet Designer and inkjet head PIJ-25NSET

The reagents used are as follows.
MMA: Methyl methacrylate HEMA: 2-Hydroxyethyl methacrylate HPMA: 4-Hydroxyphenyl methacrylate HPMA-QD: Condensation reaction of 1 mol of 4-hydroxyphenyl methacrylate with 1.1 mol of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride Compound CHMI: N-cyclohexylmaleimide PFHMA: 2- (perfluorohexyl) ethyl methacrylate MAA: AIBN methacrylate: α, α'-azobisisobutyronitrile QD1: α, α, α'-tris (4) -Hydroxyphenyl) A compound synthesized by a condensation reaction of 1 mol of -1-ethyl-4-isopropylbenzene and 1.5 mol of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride. GT-401: Tetrabutanetetracarboxylate (Tetrabutantetracarboxylate) 3,4-Epoxycyclohexylmethyl) modified ε-caprolactone (trade name: Epolide GT-401, manufactured by Daicel Co., Ltd.)
PGME: Propylene Glycol Monomethyl Ether PGMEA: Propylene Glycol Monomethyl Ether Acetate CHN: Cyclohexanone TMAH: Tetramethylammonium Hydroxide

[1] Preparation of substrate with partition wall (bank) (1) Synthesis of acrylic polymer [Synthesis Example 1-1]
MMA (10.0 g), HEMA (12.5 g), CHMI (20.0 g), HPMA (2.50 g), MAA (5.00 g) and AIBN (3.20 g) are dissolved in PGME (79.8 g). Then, the reaction was carried out at 60 to 100 ° C. for 20 hours to obtain an acrylic polymer P1 solution (solid content concentration: 40% by mass). The Mn of the acrylic polymer P1 was 3,700 and the Mw was 6,100.

[Synthesis Example 1-2]
HPMA-QD (2.50 g), PFHMA (7.84 g), MAA (0.70 g), CHMI (1.46 g) and AIBN (0.33 g) were dissolved in CHN (51.3 g) and heated to 110 ° C. By stirring and reacting for 20 hours, an acrylic polymer P2 solution (solid content concentration: 20% by mass) was obtained. The Mn of the acrylic polymer P2 was 4,300 and the Mw was 6,300.

The number average molecular weight (Mn) and weight average molecular weight (Mw) of the acrylic polymers P1 and P2 were measured by gel permeation chromatography (GPC) under the following conditions.
・ Chromatograph: GPC device LC-20AD manufactured by Shimadzu Corporation
-Column: Shodex KF-804L and 803L (manufactured by Showa Denko KK) and TSK-GEL (manufactured by Tosoh Corporation) are connected in series.-Column temperature: 40 ° C
-Detector: UV detector (254 nm) and RI detector-Eluent: tetrahydrofuran-Column flow rate: 1 mL / min

(2) Production of Positive Photosensitive Resin Composition [Production Example 1]
Acrylic polymer P1 solution (5.04 g), acrylic polymer P2 solution (0.05 g), QD1 (0.40 g), GT-401 (0.09 g) and PGMEA (6.42 g) are mixed and at room temperature. The mixture was stirred for 3 hours to obtain a uniform solution to obtain a positive photosensitive resin composition.

(3) Fabrication of Substrate with Partition (Bank) [Manufacturing Example 2]
The positive photosensitive resin composition obtained in Production Example 1 was applied to an ITO-glass substrate that had been ozone-cleaned for 10 minutes using UV-312 manufactured by Technovision Co., Ltd. using a spin coater, and then the substrate. Was prebaked (100 ° C., 120 seconds) on a hot plate to form a thin film having a film thickness of 1.2 μm. At 175 mJ / cm ² using ultraviolet rays with a wavelength of 365 nm by the ultraviolet irradiation device PLA-600FA manufactured by Canon Inc. through a mask with a pattern in which a large number of rectangles with a long side of 200 μm and a short side of 100 μm are drawn on this thin film. Exposed. Then, the thin film was immersed in a 1.0 mass% TMAH aqueous solution for 120 seconds for development, and then the thin film was washed with running water for 20 seconds using ultrapure water. Next, the thin film on which this rectangular pattern was formed was post-baked (230 ° C., 30 minutes) and cured to prepare a substrate with a partition wall.

[2] Synthesis of charge-transporting organic compound [Synthesis Example 2-1] Synthesis of aniline derivative A

1.00 g of N1- (4-aminophenyl) benzene-1,4-diamine, 8.89 g of 2-bromo-9-phenyl-9H-carbazole, 112 mg of palladium acetate and 3.47 g of tert-butoxysodium were placed in a flask. After that, the inside of the flask was replaced with nitrogen. Toluene (30 mL) and a previously prepared toluene solution of di-tert-butyl (phenyl) phosphine (2.75 mL (concentration: 81.0 g / L)) were added thereto, and the mixture was stirred at 90 ° C. for 6 hours.
After the stirring was completed, the reaction mixture was cooled to room temperature, and the cooled reaction mixture, toluene, and ion-exchanged water were mixed and subjected to liquid separation treatment. The obtained organic layer was dried over sodium sulfate and concentrated. The concentrated solution was filtered through silica gel, 0.2 g of activated carbon was added to the obtained filtrate, and the mixture was stirred at room temperature for 30 minutes.
Then, the activated carbon was removed by filtration, and the filtrate was concentrated. The concentrate was added dropwise to a mixed solvent of methanol and ethyl acetate (500 mL / 500 mL), the obtained slurry was stirred at room temperature overnight, and then the slurry was filtered to recover the filtrate. The obtained filtrate was dried to obtain the desired aniline derivative A (yield 5.88 g, yield 83%).
¹ H-NMR (500MHz, THF-d ₈ ) δ [ppm]: 8.02-8.10 (m, 10H), 7.48-7.63 (m, 22H), 7.28-7.39 (m, 14H), 7.19-7.24 (m, 10H), 7.02-7.09 (m, 12H).
MALDI-TOF-MS m / Z found: 1404.88 ([M] ⁺ calcd: 1404.56).

[Synthesis Example 2-2] Synthesis of Aniline Derivative B Aniline derivative B represented by the following formula was synthesized according to the method described in International Publication No. 2015/050253.

[3] Synthesis of dopant [Synthesis Example 3-1] Synthesis of aryl sulfonic acid ester C Aryl sulfonic acid ester C represented by the following formula was synthesized according to the method described in International Publication No. 2017/217455.

[Synthesis Example 3-2] Synthesis of Aryl Sulfonic Acid Ester First, aryl sulfonic acid D'represented by the following formula was synthesized according to the method described in International Publication No. 2015/111654.
Thionyl chloride (25 g) and N, N-dimethylformamide (0.4 mL) as a catalyst were added to aryl sulfonic acid D'(4.97 g, 10 mmol), heated and refluxed for 1 hour, and then thionyl chloride was distilled off. A solid containing the acid chloride of aryl sulfonic acid D'was obtained. This compound was used in the next step without further purification.
Chloroform (30 mL) and pyridine (20 mL) were added to the solid, and 6.24 g (60 mmol) of propylene glycol monoethyl ether was added at 0 ° C. The temperature was raised to room temperature, and then the mixture was stirred for 1.5 hours. After distilling off the solvent, water was added, the mixture was extracted with ethyl acetate, and the organic layer was dried over sodium sulfate. After filtration and concentration, the obtained crude product was purified by silica gel column chromatography (hexane / ethyl acetate) to obtain 1.32 g of aryl sulfonic acid ester D as a white solid (yield 20% (aryl sulfonic acid). Two-step yield from D')). ¹ The measurement results of ¹ H-NMR and LC / MS are shown below.
^{1 1} H-NMR (500MHz, CDCl ₃ ): δ 0.89-0.95 (m, 6H), 1.34 and 1.39 (a pair of d, J = 6.5Hz, 6H), 3.28-3.50 (m, 8H), 4.81-4.87 (m, 2H), 7.26 (s, 1H), 8.22 (d, J = 9.0Hz, 1H), 8.47 (s, 1H), 8.54 (d, J = 9.0Hz, 1H), 8.68 (s, 1H) ..
LC / MS (ESI ⁺ ) m / z; 687 [M + NH ₄ ] ⁺

[4] Preparation of charge-transporting varnish [Example 1-1]
To 0.003 g of aniline derivative A, 0.325 g of aryl sulfonic acid ester and 0.018 g of F4TCNQ, 5.00 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added and stirred at room temperature. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish A.

[Example 1-2]
To 0.057 g of the aniline derivative A, 0.245 g of the aryl sulfonic acid ester and 0.025 g of F4TCNQ, 5.0 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was stirred at room temperature. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish B.

[Example 1-3]
To 0.184 g of the aniline derivative A, 0.327 g of the aryl sulfonic acid ester and 0.015 g of DDQ, 5.00 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was stirred at room temperature. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish C.

[Example 1-4]
To 0.003 g of aniline derivative B, 0.325 g of aryl sulfonic acid ester and 0.018 g of F4TCNQ, 5.0 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was stirred at room temperature. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish D.

[Example 1-5]
To aniline derivative B 0.257 g, aryl sulfonic acid ester D 0.245 g and F4TCNQ 0.025 g, triethylene glycol butyl methyl ether 5.0 g, diisopropyl malonic acid 3.00 g and dimethyl phthalate 2.00 g were added, and the mixture was stirred at room temperature. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish E.

[Example 1-6]
To aniline derivative B 0.184 g, aryl sulfonic acid ester C 0.327 g and DDQ 0.015 g, triethylene glycol butyl methyl ether 5.0 g, diisopropyl malonic acid 3.0 g and dimethyl phthalate 2.0 g were added, and the mixture was stirred at room temperature. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish F.

[Comparative Example 1-1]
To 0.009 g of aniline derivative A and 0.047 g of F4TCNQ, 5.0 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was dissolved by stirring at room temperature. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish G.

[Comparative Example 1-2]
To 0.487 g of aniline derivative A and 0.039 g of DDQ, 5.00 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was dissolved by stirring at room temperature. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish H.

[Comparative Example 1-3]
To 0.007 g of aniline derivative B and 0.047 g of F4TCNQ, 5.0 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was dissolved by stirring at room temperature. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish I.

[Comparative Example 1-4]
To 0.487 g of aniline derivative B and 0.039 g of DDQ, 5.00 g of triethylene glycol butyl methyl ether, 3.00 g of diisopropyl malonic acid and 2.00 g of dimethyl phthalate were added, and the mixture was dissolved by stirring at room temperature. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish J.

[Comparative Example 1-5]
Polymer H1 (TFB polymer, LT-N148 manufactured by Luminescence Technology Co., Ltd.) represented by the following formula (H1) is 0.180 g, aryl sulfonic acid ester C 0.120 g and F4TCNQ 0.002 g, and triethylene glycol butyl methyl ether 5.00 g. 3.00 g of diisopropyl malonate and 2.00 g of dimethyl phthalate were added and stirred at room temperature to dissolve. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish K.

[Comparative Example 1-6]
To 0.180 g of polymer H1. It was dissolved. The obtained solution was filtered through a PTFE syringe filter having a pore size of 0.2 μm to prepare a charge-transporting varnish L.

[5] Fabrication and characterization of single-layer device (SLD) [Example 2-1]
The charge-transporting varnish A is applied to an ITO substrate using a spin coater, dried in the air at 120 ° C. for 1 minute, and then fired at 200 ° C. for 15 minutes to form a uniform thin film having a thickness of 50 nm on the ITO substrate. Was formed. As the ITO substrate, a 25 mm × 25 mm × 0.7 t glass substrate having a patterned ITO film having a thickness of 150 nm formed on the surface was used, and the surface was subjected to an O ₂ plasma cleaning device (150 W, 30 seconds) before use. The above impurities were removed. Next, the single-layer element A was formed by forming aluminum on the ITO substrate on which the thin film was formed at a vacuum level of 1.0 × 10 ^-5 Pa at 0.2 nm / sec to 80 nm. Made.
In order to prevent deterioration of characteristics due to the influence of oxygen, water, etc. in the air, the elements were sealed with a sealing substrate and then their characteristics were evaluated. Sealing was performed by the following procedure. In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -76 ° C or less, the elements are placed between the sealing substrates, and the sealing substrate is attached with an adhesive (Morresco Moisture Cut WB90US (P) manufactured by MORESCO Corporation). At this time, a water trapping agent (HD-071010W-40 manufactured by Dynic Co., Ltd.) was housed in the sealing substrate together with the element. The bonded sealing substrate was irradiated with UV light (wavelength: 365 nm, Irradiation amount: 6,000 mJ / cm ² ) and then annealing treatment at 80 ° C. for 1 hour to cure the adhesive.

[Example 2-2]
A single-layer device B was produced in the same manner as in Example 2-1 except that the charge-transporting varnish B was used instead of the charge-transporting varnish A.

[Example 2-3]
A single-layer device C was produced in the same manner as in Example 2-1 except that the charge-transporting varnish C was used instead of the charge-transporting varnish A.

[Example 2-4]
A single-layer element D was produced in the same manner as in Example 2-1 except that the charge-transporting varnish D was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Example 2-5]
A single-layer element E was produced in the same manner as in Example 2-1 except that the charge-transporting varnish E was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Example 2-6]
A single-layer device F was produced in the same manner as in Example 2-1 except that the charge-transporting varnish F was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Comparative Example 2-1]
A single-layer device G was produced in the same manner as in Example 2-1 except that the charge-transporting varnish G was used instead of the charge-transporting varnish A.

[Comparative Example 2-2]
A single-layer device H was produced in the same manner as in Example 2-1 except that the charge-transporting varnish H was used instead of the charge-transporting varnish A.

[Comparative Example 2-3]
A single-layer device I was produced in the same manner as in Example 2-1 except that the charge-transporting varnish I was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Comparative Example 2-4]
A single-layer element J was produced in the same manner as in Example 2-1 except that the charge-transporting varnish J was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

The current density when the manufactured single-layer element was driven at 3 V was measured. The results are shown in Table 1.

As shown in Table 1, it was found that the thin film prepared from the charge-transporting varnish of the present invention exhibited good charge-transporting property.

[6] Fabrication and Characteristic Evaluation of Hole-Only Device (HOD) In the following Examples and Comparative Examples, the same ITO substrate as described above was used.
[Example 3-1]
The charge-transporting varnish A is applied to an ITO substrate using a spin coater, dried in the air at 120 ° C. for 1 minute, and then fired at 200 ° C. for 15 minutes to form a uniform thin film of 50 nm on the ITO substrate. did.
A thin film of α-NPD and aluminum was sequentially laminated on it using a thin film deposition apparatus (vacuum degree 1.0 × 10 ^-5 Pa) to obtain a hole-only element A. The vapor deposition was carried out under the condition of a vapor deposition rate of 0.2 nm / sec. The film thicknesses of the α-NPD and aluminum thin films were 30 nm and 80 nm, respectively.
The element was sealed in the same manner as in Example 2-1 and then its characteristics were evaluated.

[Example 3-2]
A hole-only element B was produced in the same manner as in Example 3-1 except that the charge-transporting varnish B was used instead of the charge-transporting varnish A.

[Example 3-3]
A hole-only element C was produced in the same manner as in Example 3-1 except that the charge-transporting varnish C was used instead of the charge-transporting varnish A.

[Example 3-4]
A hole-only element D was produced in the same manner as in Example 3-1 except that the charge-transporting varnish D was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Example 3-5]
A hole-only element E was produced in the same manner as in Example 3-1 except that the charge-transporting varnish E was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Example 3-6]
A hole-only element F was produced in the same manner as in Example 3-1 except that the charge-transporting varnish F was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Comparative Example 3-1]
A hole-only element G was produced in the same manner as in Example 3-1 except that the charge-transporting varnish G was used instead of the charge-transporting varnish A.

[Comparative Example 3-2]
A hole-only element H was produced in the same manner as in Example 3-1 except that the charge-transporting varnish H was used instead of the charge-transporting varnish A.

[Comparative Example 3-3]
A hole-only element I was produced in the same manner as in Example 3-1 except that the charge-transporting varnish I was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Comparative Example 3-4]
A hole-only element J was produced in the same manner as in Example 3-1 except that the charge-transporting varnish J was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

The current density when the manufactured hole-only element was driven at 3 V was measured. The results are shown in Table 2.

As shown in Table 2, it was found that the thin film prepared from the charge transporting varnish of the present invention exhibits good hole injectability into α-NPD, which is often used as a hole transporting layer.

[7] Fabrication and Characteristic Evaluation of Organic EL Element In the following Examples and Comparative Examples, the same ITO substrate as described above was used.
[Example 4-1]
The charge-transporting varnish A is applied to an ITO substrate using a spin coater, dried in the air at 120 ° C. for 1 minute, and then fired at 200 ° C. for 15 minutes to form a uniform thin film of 50 nm on the ITO substrate. did.
On it, α-NPD was deposited at 0.2 nm / sec at 30 nm using a thin film deposition apparatus (vacuum degree 1.0 × 10 ^-5 Pa). Next, CBP and Ir (PPy) ₃ were co-deposited. For co-evaporation, the vapor deposition rate was controlled so that the concentration of Ir (PPy) ₃ was 6%, and 40 nm was laminated. Next, a thin film of tris (8-quinolinolate) aluminum (III) (Alq ₃ ), lithium fluoride, and aluminum was sequentially laminated to obtain an organic EL element A. At this time, the vapor deposition rate was 0.2 nm / sec for Alq ₃ and aluminum, and 0.02 nm / sec for lithium fluoride, and the film thicknesses were 20 nm, 0.5 nm, and 80 nm, respectively.
The element was sealed in the same manner as in Example 2-1 and then its characteristics were evaluated.

[Example 4-2]
An organic EL element B was produced in the same manner as in Example 4-1 except that the charge transporting varnish B was used instead of the charge transporting varnish A.

[Example 4-3]
The organic EL element C was produced in the same manner as in Example 4-1 except that the charge transporting varnish C was used instead of the charge transporting varnish A.

[Example 4-4]
An organic EL element D was produced in the same manner as in Example 4-1 except that the charge-transporting varnish D was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Example 4-5]
An organic EL element E was produced in the same manner as in Example 4-1 except that the charge-transporting varnish E was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Example 4-6]
An organic EL element F was produced in the same manner as in Example 4-1 except that a charge-transporting varnish F was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Comparative Example 4-1]
An organic EL device G was produced in the same manner as in Example 4-1 except that the charge transporting varnish G was used instead of the charge transporting varnish A.

[Comparative Example 4-2]
The organic EL element H was produced in the same manner as in Example 4-1 except that the charge transporting varnish H was used instead of the charge transporting varnish A.

[Comparative Example 4-3]
An organic EL element I was produced in the same manner as in Example 4-1 except that the charge-transporting varnish I was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

[Comparative Example 4-4]
An organic EL element J was produced in the same manner as in Example 4-1 except that the charge-transporting varnish J was used instead of the charge-transporting varnish A and was fired at 230 ° C. for 15 minutes.

The brightness when the produced organic EL element was driven at 8 V was measured. The results are shown in Table 3.

As shown in Table 3, the thin film prepared from the charge-transporting varnish of the present invention showed high organic EL characteristics.

[7] Fabrication of a substrate with a charge-transporting thin film by coating with an inkjet [Example 5-1]
The charge-transporting varnish A is diluted with a solvent so that the solid content concentration is 2.3% by mass, and an inkjet device is placed in a rectangular opening (film forming region) on the partition substrate prepared in Production Example 2. Discharged using. When the charge transporting varnish was diluted, it was diluted so that the composition ratio of the mixed solvent in the varnish did not change. Immediately thereafter, the obtained coating film was dried under reduced pressure (vacuum degree) of 10 Pa or less at room temperature for 15 minutes, and then dried at 200 ° C. for 15 minutes at normal pressure to form a charge-transporting thin film in the partition wall. A substrate A with a charge-transporting thin film was obtained. The charge-transporting thin film was discharged so that the film thickness near the center of the opening was 90 to 110 nm.

[Example 5-2]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish B was used instead of the charge-transporting varnish A.

[Example 5-3]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish C was used instead of the charge-transporting varnish A.

[Example 5-4]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish D was used instead of the charge-transporting varnish A.

[Example 5-5]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish E was used instead of the charge-transporting varnish A.

[Example 5-6]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish F was used instead of the charge-transporting varnish A.

[Comparative Example 5-1]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish G was used instead of the charge-transporting varnish A.

[Comparative Example 5-2]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish H was used instead of the charge-transporting varnish A.

[Comparative Example 5-3]
A substrate with a charge-transporting thin film was prepared in the same manner as in Example 5-1 except that the charge-transporting varnish I was used instead of the charge-transporting varnish A.

[Comparative Example 5-4]
A substrate K with a charge-transporting thin film was produced in the same manner as in Example 5-1 except that the charge-transporting varnish K was used instead of the charge-transporting varnish A, but an uneven structure was generated on the film surface. No flat film was obtained.

[Comparative Example 5-5]
A substrate L with a charge-transporting thin film was produced in the same manner as in Example 5-1 except that the charge-transporting varnish L was used instead of the charge-transporting varnish A, but an uneven structure was generated on the film surface. No flat film was obtained.

The pile-up index was calculated for the prepared charge-transporting thin film. The pile-up index is (B) when the partition wall (bank) width is A (μm) and the film thickness range of + 10% from the film thickness of the charge-transporting thin film at the center of the partition wall (bank) is B (μm). It was calculated as / A) × 100 (%). The results are shown in Tables 4-5. In addition, Examples 5-1 to 5-3 and 5-6 and Comparative Examples 5-1 and 5-2 have a short side, and Examples 5-4 and 5-5 and Comparative Example 5-3 have a long side. The pile-up index was calculated as the partition wall width for each.

As shown in Tables 4 and 5, the charge-transporting thin film formed by using the charge-transporting varnish of the present invention had good flatness and showed a high pile-up index of 95% or more. On the other hand, the charge-transporting thin film formed by using the charge-transporting varnish of the comparative example showed a lower pile-up index as compared with the example. Further, when the polymer H1 was used (Comparative Examples 5-4 and 5-5), an uneven structure was generated on the film surface, and a flat film could not be obtained.

Claims

A charge-transporting varnish containing (A) a monodisperse charge-transporting organic compound, (B) a dopant, and (C) an organic solvent.
A charge-transporting varnish in which the dopant (B) comprises (B1) an aryl sulfonic acid ester compound and (B2) a halogenated tetracyanoquinodimethane or (B3) a halogenated or cyanated benzoquinone.
The charge-transporting varnish according to claim 1, wherein the monodisperse charge-transporting organic compound is an arylamine derivative.
The transportable varnish according to claim 2, wherein the arylamine derivative is a tertiary arylamine compound.
The charge transporting varnish according to claim 3, wherein the tertiary arylamine compound has at least one nitrogen atom and all nitrogen atoms have a tertiary arylamine structure.
The charge transporting varnish according to claim 4, wherein the tertiary arylamine compound has at least two nitrogen atoms and all nitrogen atoms have a tertiary arylamine structure.
The charge-transporting varnish according to any one of claims 1 to 5, wherein the aryl sulfonic acid ester compound is represented by the following formula (B1) or (B1').

[In the formula, A 1 may have a substituent and is represented by an m-valent hydrocarbon group having 6 to 20 carbon atoms containing one or more aromatic rings or the following formula (B1a) or (B1b). Is an m-valent group derived from the compound to be

(In the formula, W 1 and W 2 may independently have -O-, -S-, -S (O)-or -S (O 2 )-, or -N. -, -Si-, -P- or -P (O)-)
A 2 is -O-, -S- or -NH-;
A 3 is, or an (n + 1) -valent aromatic group with 6 to 20 carbon atoms;
X 1 is an alkylene group having 2 to 5 carbon atoms, and an —O—, —S— or carbonyl group may be interposed between the carbon atoms of the alkylene group, and one of the hydrogen atoms of the alkylene group. Part or all may be further substituted with an alkyl group having 1 to 20 carbon atoms;
X 2 is a single bond, -O-, -S- or -NR-, and R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms;
X 3 is a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent;
m is an integer that satisfies 1 ≦ m ≦ 4.
n is an integer that satisfies 1 ≦ n ≦ 4. ]
The charge transporting varnish according to claim 6, wherein the aryl sulfonic acid ester compound is represented by any of the following formulas (B1-1) to (B1-3).

(In the formula, 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 may have a substituent. It is a monovalent hydrocarbon group having 2 to 20 carbon atoms;
A 11 is an m-valent group derived from perfluorobiphenyl, A 12 is an -O- or -S-, and A 13 is a (n + 1) -valent group derived from naphthalene or anthracene. Yes;
m and n are the same as described above. )

(In the formula, R s6 and R s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group, and R s8 is a linear or branched monovalent fat. Although it is a group hydrocarbon group, the total number of carbon atoms of R s6 , R s7 and R s8 is 6 or more;
A 14 is an m-valent hydrocarbon group containing one or more aromatic rings, which may have a substituent, A 15 is —O— or —S—, and A 16 is ( It is an n + 1) valent aromatic group;
m and n are the same as described above. )

(In the formula, R s9 to R s13 are independently hydrogen atom, nitro group, cyano group, halogen atom, alkyl group having 1 to 10 carbon atoms, alkyl halide group having 1 to 10 carbon atoms, or carbon number of carbon atoms. 2-10 halogenated alkenyl groups;
R s14 to R s17 are independently hydrogen atoms or linear or branched monovalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms;
R s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or −OR s19 , and R s19 has 2 to 20 carbon atoms which may have a substituent. Is a monovalent hydrocarbon group of
A 17 is -O-, -S- or -NH-;
A 18 is an (n + 1) -valent aromatic group;
n is the same as described above. )
(B2) The charge-transporting varnish according to any one of claims 1 to 7, wherein the halogenated tetracyanoquinodimethane is represented by the following formula (B2).

(In the formula, R q1 to R q4 are independently hydrogen atoms or halogen atoms, but at least one is a halogen atom.)
(B3) The charge-transporting varnish according to any one of claims 1 to 8, wherein the halogenated or cyanated benzoquinone is represented by the following formula (B3).

(In the formula, R q5 to R q8 are independently hydrogen atoms, halogen atoms or cyano groups, but at least one is a halogen atom or cyano group.)
The content of the (B1) aryl sulfonic acid ester compound is 0.01 to 50 in molar ratio with respect to the (B2) halogenated tetracyanoquinodimethane or the (B3) halogenated or cyanated benzoquinone. The charge-transporting varnish according to any one of claims 1 to 9.
The charge-transporting varnish according to any one of claims 1 to 10, wherein the monodisperse charge-transporting organic compound has a molecular weight of 200 to 9,000.
The charge-transporting varnish according to any one of claims 1 to 11, wherein the organic solvent contains a low-polarity organic solvent.
A charge-transporting thin film obtained from the charge-transporting varnish according to any one of claims 1 to 12.
The organic electroluminescence device including the charge transporting thin film according to claim 13.
The organic electroluminescence device according to claim 14, wherein the charge transporting thin film is a hole injection layer or a hole transport layer.