Charge transport varnish

Abstract

For example, a charge-transporting varnish containing an aniline derivative having a repeating m-phenylene unit in the molecule represented by the following formula and an organic solvent can be fired at low temperature to provide a thin film with excellent charge transport properties and a high refractive index. When this thin film is used as a hole injection layer, etc., it can provide an organic EL device with excellent characteristics. #imgabs0#

Description

Technical Field

[0001] The present invention relates to a charge-transporting varnish. Background Art

[0002] In organic electroluminescent (OLED) devices, charge-transporting thin films composed of organic compounds are used as the light-emitting layer and charge-injection layer. The hole-injection layer, in particular, facilitates the transfer of charge between the anode and the hole-transport layer or light-emitting layer, playing a crucial role in achieving low-voltage operation and high brightness in OLED devices.

[0003] Hole injection layer formation methods are broadly categorized into dry methods, typically vapor deposition, and wet methods, typically spin coating. Comparing these methods, wet methods are able to efficiently produce thin films with high flatness over large areas. Therefore, with the increasing size of organic EL displays, there is a growing demand for hole injection layers that can be formed using wet methods.

[0004] In view of this actual situation, the inventors have developed charge transport materials and compounds with good solubility in organic solvents. The charge transport materials can be applied to various wet processes and provide thin films that can achieve excellent EL element characteristics when applied to the hole injection layer of an organic EL element (for example, refer to patent documents 1 to 3).

[0005] On the other hand, various studies have been conducted to improve the performance of organic EL devices. For purposes such as improving light extraction efficiency, research has been conducted on adjusting the refractive index of the functional films used. Specifically, attempts have been made to achieve higher device efficiency by using hole injection layers and hole transport layers with higher or lower refractive indices, taking into account the overall structure of the device and the refractive indices of other adjacent components (e.g., Patent Documents 4 and 5).

[0006] Therefore, the refractive index is an important factor in the design of an organic EL element, and is also regarded as an important physical property value to be considered for materials used in organic EL elements.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2008 / 129947

[0010] Patent Document 2: International Publication No. 2015 / 050253

[0011] Patent Document 3: International Publication No. 2017 / 217457

[0012] Patent Document 4: Japanese Patent Application No. 2007-536718

[0013] Patent Document 5: Japanese Patent Application No. 2017-501585 Summary of the Invention

[0014] Problems to be solved by the invention

[0015] The present invention has been made in view of such actual circumstances, and its object is to provide a charge transport varnish that, by low temperature firing, provides a thin film having good charge transport properties and a high refractive index, and that, when used as a hole injection layer or the like, can realize an organic EL element having excellent characteristics.

[0016] Means for solving problems

[0017] The present inventors have conducted intensive studies to achieve the above-mentioned objectives and have discovered that a charge-transporting varnish comprising a predetermined aniline derivative having a repeating unit of meta-phenylene in the molecule can provide a thin film having excellent charge-transporting properties and a high refractive index by low-temperature calcination at a temperature of 200°C or less. This thin film, when used in a hole injection layer or the like, can provide an organic EL element having excellent characteristics, thereby completing the present invention.

[0018] That is, the present invention provides:

[0019] 1. A charge transporting varnish comprising an aniline derivative represented by the following formula (1) and an organic solvent.

[0020] [Chemistry 1]

[0021]

[0022] [Where Ph 1 Each independently represents a group represented by formula (P1) or formula (P2), at least one of which is a group represented by formula (P1),

[0023] [Chemistry 2]

[0024]

[0025] (Where R 1 ~R 4 Each independently represents a hydrogen atom, a cyano group, or 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 which may be substituted by a cyano group.

[0026] Ar 0 each independently represents a group represented by formula (B0),

[0027] [Chemistry 3]

[0028]

[0029] (where Ar B represents a single bond or a phenylene group which may be substituted by any substituent other than the E group (excluding substituents containing a pyridine ring. The same applies hereinafter). B In the case of the above-mentioned phenylene group, it may be G or other aromatic rings to form a part of a fused ring,

[0030] Ar G Each independently represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with any substituent other than the E group,

[0031] E represents a single bond, -C(R a )2-、-NR b -, -NH-, N, -O- or -S-,

[0032] R a Each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom, and in R a When it is the above-mentioned monovalent hydrocarbon group, R a They can combine with each other and form a ring together with carbon atoms, R b represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom,

[0033] In Ar B When E is a single bond and Ar G is a naphthyl group which may be substituted with any substituent other than the E group,

[0034] In E is -C(R a )2-yl, Ar B and Ar G Combined with each other to form a fused ring, in which case Ar B and Ar G may combine with each other to form a fused ring,

[0035] n G Ar combined with E G The number of bases is 2 when E is N and 1 when there are 2 Ar G In the case of a nitrogen atom, they may be combined with each other to form a condensed ring.

[0036] k represents an integer greater than or equal to 1.]

[0037] 2.1 The charge transport varnish, wherein the Ar 0 are each independently a group represented by any one of formulae (B1) to (B16),

[0038] [Chemistry 4]

[0039]

[0040] (Where R 5 ~R 25 、R 28 ~R 49 and R 51 ~R 194 Each independently represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, or a diphenylamino group which may be substituted with a halogen atom, a nitro group, or a cyano group, 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, and R 26 and R 27 Each independently represents a hydrogen atom, which may be replaced by Z 1 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 1 Substituted alkenyl with 2 to 20 carbon atoms, which may be Z 1 The substituted alkynyl group having 2 to 20 carbon atoms may be Z 2 The substituted aryl group having 6 to 20 carbon atoms may be Z 2 Substituted heteroaryl having 2 to 20 carbon atoms, R 50 Represents hydrogen atoms, which can be Z 1 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 1 Substituted alkenyl with 2 to 20 carbon atoms, which may be Z 1 The substituted alkynyl group having 2 to 20 carbon atoms may be Z 2 The substituted aryl group having 6 to 20 carbon atoms may be Z 2 Substituted heteroaryl having 2 to 20 carbon atoms, Z 1 Represents a halogen atom, nitro, cyano, diphenylamino, which can be Z 3 The substituted aryl group having 6 to 20 carbon atoms may be Z 3 Substituted heteroaryl having 2 to 20 carbon atoms, Z 2 Represents a halogen atom, nitro, cyano, diphenylamino, which can be Z 3 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 3 The substituted alkenyl group having 2 to 20 carbon atoms may be Z 3 Substituted alkynyl having 2 to 20 carbon atoms, Z 3 represents a halogen atom, a nitro group, a cyano group or a diphenylamino group, Ar 4 Each independently represents an aryl group having 6 to 20 carbon atoms which may be substituted with a di(aryl group having 6 to 20 carbon atoms)amino group.

[0041] 3.2 The charge-transporting varnish, wherein the aniline derivative represented by the formula (1) is represented by any one of the formulas (1-1) to (1-4),

[0042] [Chemistry 5]

[0043]

[0044] (Ar 1 ~Ar 3 Different from each other, it is a group represented by any one of the above formulas (B1) to (B16), in each formula, Ar 1 All represent the same group, Ar 2 All represent the same group, Ar 3 All represent the same group.)

[0045] 4. The charge transporting varnish according to any one of 1 to 3, wherein the number (n m ) and the number of groups represented by the formula (P2) (n p ) satisfies 0.5≤n m / (n m +n p ),

[0046] 5. The charge-transporting varnish according to any one of 1 to 4, comprising a dopant substance,

[0047] 6.5 The charge transport varnish, wherein the dopant substance is an arylsulfonate compound,

[0048] 7. A charge transporting thin film produced using the charge transporting varnish according to any one of 1 to 6.

[0049] 8. An electronic component comprising the charge transport thin film of 7,

[0050] 9. An organic electroluminescent element comprising the charge transport thin film of 7.

[0051] 10.9 The organic electroluminescent device, wherein the charge transport thin film is a hole injection layer or a hole transport layer.

[0052] Effects of the Invention

[0053] By using the charge-transporting varnish of the present invention, a thin film having a high refractive index can be produced. Furthermore, even when fired at a low temperature of 200° C. or lower, a thin film having excellent charge-transporting properties can be produced.

[0054] The charge-transporting thin film obtained from the charge-transporting varnish of the present invention can be suitably used as a thin film for electronic devices including organic EL devices. By using it as a hole injection layer or hole transport layer, particularly a hole injection layer, an organic EL device with excellent characteristics can be obtained. DETAILED DESCRIPTION

[0055] The present invention is described in more detail below.

[0056] The charge-transporting varnish of the present invention contains an aniline derivative represented by the following formula (1) and an organic solvent.

[0057] [Chemistry 6]

[0058]

[0059] In formula (1), Ph 1 Each independently represents a group represented by formula (P1) or formula (P2), as described later, (k+1) Ph 1 At least one of the groups is a group represented by formula (P1).

[0060] [Chemistry 7]

[0061]

[0062] Among them, R 1 ~R 4 Each independently represents a hydrogen atom, a cyano group, or 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 which may be substituted by a cyano group.

[0063] The alkyl group having 1 to 20 carbon atoms may be linear, branched or cyclic. Examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl; and cyclic alkyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl and bicyclodecyl.

[0064] Specific examples of the alkenyl group having 2 to 20 carbon atoms include ethenyl, n-1-propenyl, n-2-propenyl, 1-methylethenyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl, and n-1-eicosenyl.

[0065] Specific examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-2-pentynyl, n-3-pentynyl, n-4-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl, 1,1-dimethyl-n-propynyl, n-1-hexynyl, n-1-decynyl, n-1-pentadeynyl, and n-1-eicosynyl.

[0066] Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, and 9-phenanthrenyl.

[0067] Specific examples of the heteroaryl group having 2 to 20 carbon atoms include oxygen-containing heteroaryl groups such as 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, and 5-isoxazolyl; sulfur-containing heteroaryl groups such as 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, and 5-isothiazolyl; 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrazinyl, 3-pyrazinyl, 5-pyrazinyl, 6-pyrazinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 3-pyridazinyl, 4-pyridazinyl, 5-pyridazinyl, 6-pyridazinyl, 1,2,3-triazin-4-yl, 1,2,3-triazin-5-yl, 1,2,4-triazine -3-yl, 1,2,4-triazine-5-yl, 1,2,4-triazine-6-yl, 1,3,5-triazine-2-yl, 1,2,4,5-tetrazine-3-yl, 1,2,3,4-tetrazine-5-yl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl quinolinyl, 5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl, 8-isoquinolinyl, 2-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 2-quinazolinyl, 4-quinazolinyl, 5-quinazolinyl, 6-quinazolinyl, 7-quinazolinyl, 8-quinazolinyl, 3-cinnolinyl, 4-cinnolinyl, 5-cinnolinyl, 6-cinnolinyl, 7-cinnolinyl, 8-cinnolinyl, and the like nitrogen-containing heteroaryl groups.

[0068] Among these, R 1 ~R 4, preferably a hydrogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms which may be substituted by a cyano group, an aryl group having 6 to 20 carbon atoms which may be substituted by a cyano group, or a heteroaryl group having 2 to 20 carbon atoms which may be substituted by a cyano group; more preferably a hydrogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted by a cyano group, or a phenyl group which may be substituted by a cyano group; further preferably a hydrogen atom and a methyl group; most preferably a hydrogen atom.

[0069] That is, the group represented by formula (P1) is most preferably an unsubstituted m-phenylene (benzene-1,3-diyl) group, and the group represented by formula (P2) is most preferably an unsubstituted p-phenylene (benzene-1,4-diyl) group.

[0070] In the above formula (1), Ar 0 Each independently represents a group represented by formula (B0).

[0071] [Chemistry 8]

[0072]

[0073] Where Ar B represents a single bond or a phenylene group which may be substituted by any substituent other than the E group (excluding substituents containing a pyridine ring. The same applies hereinafter). B In the case of the above-mentioned phenylene group, it may be G or part of a fused ring formed by combining with other aromatic rings.

[0074] Examples of the phenylene group in the phenylene group which may be substituted with any substituent other than the E group include o-phenylene, m-phenylene, and p-phenylene. From the viewpoint of ease of synthesis of the aniline derivative, m-phenylene and p-phenylene are preferred, and considering the solubility of the aniline derivative, p-phenylene is more preferred.

[0075] Ar G Each independently represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted with any substituent other than the E group. Specific examples of these aryl and heteroaryl groups include the same groups as exemplified above, but are not limited thereto.

[0076] Among them, as Ar G , preferably an aryl group having 6 to 10 carbon atoms or a heteroaryl group having 2 to 10 carbon atoms which may be substituted by a substituent other than an E group, more preferably an aryl group having 6 to 10 carbon atoms which may be substituted by a substituent other than an E group, further preferably a phenyl group, a 1-naphthyl group, or a 2-naphthyl group which may be substituted by a substituent other than an E group.

[0077] As a substitute for Ar B and Ar GSubstituents other than the E group in the pyridine ring are not particularly limited as long as they are substituents containing the pyridine ring. Examples include a halogen atom, a nitro group, a cyano group, a diphenylamino group, 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, and diphenylamino groups, alkyl groups, alkenyl groups, and alkynyl groups substituted with these groups; and alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and aryl groups having 6 to 20 carbon atoms substituted with aryl groups. Specific examples of the alkyl group, alkenyl group, alkynyl group, and aryl group include the same groups as those exemplified above, but are not limited thereto.

[0078] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0079] E represents a single bond, -C(R a )2-、-NR b -, -NH-, N, -O- or -S-.

[0080] Among them, R a Each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom, and in R a When it is the above-mentioned monovalent hydrocarbon group, R a They can combine with each other to form a ring together with the carbon atom. b represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom.

[0081] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and heteroaryl groups having 2 to 20 carbon atoms. Specific examples thereof include the same groups as those exemplified above. Furthermore, these groups may be further substituted with a substituent.

[0082] Examples of such substituents include a halogen atom, a nitro group, a cyano group, a diphenylamino group, 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, a heteroaryl group having 2 to 20 carbon atoms, and groups in which these groups are further substituted.

[0083] Furthermore, in Ar B When it is a single bond, E is also a single bond, and Ar G It is a naphthyl group which may be substituted with an arbitrary substituent group other than the E group. Examples of such a naphthyl group include 1-naphthyl and 2-naphthyl.

[0084] In addition, when E is -C(R a )2-yl, ArB and Ar G Combined with each other to form a fused ring, in which case Ar B and Ar G may combine with each other to form a fused ring.

[0085] n G Ar combined with E G The number of bases is 2 when E is N and 1 when there are 2 Ar G In the case of alkyl groups, they may be bonded to each other to form a condensed ring together with the nitrogen atom.

[0086] k represents an integer of 1 or greater, and is preferably 10 or less, more preferably 5 or less, further preferably 4 or less, and even more preferably 3 or less, from the viewpoint of the solubility of the aniline derivative.

[0087] As described above, the aniline derivative used in the present invention contains at least one meta-phenylene structure in its linear chain, and the (k+1) Ph in formula (1) 1 At least one of the groups represents a group represented by formula (P1).

[0088] The number (n) of the groups represented by the formula (P1) in the formula (1) is m ) and the number of groups represented by formula (P2) (n p ) satisfies n m +n p = k + 1. If the balance among the solubility of the aniline derivative, the charge transport property of the obtained charge transport thin film, the refractive index, etc. is taken into consideration, n m and n p Preferably, 0.5≤n m / (n m +n p ), more preferably satisfying 0.6≤n m / (n m +n p ), further preferably satisfying 0.8≤n m / (n m +n p ), and further preferably satisfying 0.9≤n m / (n m +n p ), preferably satisfying 1=n m / (n m +n p ).

[0089] In a preferred embodiment of the present invention, Ar in formula (1) 0Each independently represents a group represented by any one of formulae (B1) to (B16), and a group represented by any one of formulae (B1′) to (B16′-5) is particularly preferred.

[0090] [Chemistry 9]

[0091]

[0092] [Chemistry 10]

[0093]

[0094] [Chemistry 11]

[0095]

[0096] Among them, R 5 ~R 25 、R 28 ~R 49 and R 51 ~R 194 Each independently represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, or a diphenylamino group which may be substituted with a halogen atom, a nitro group, or a cyano group, 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, and R 26 and R 27 Each independently represents a hydrogen atom, which may be replaced by Z 1 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 1 Substituted alkenyl with 2 to 20 carbon atoms, which may be Z 1 The substituted alkynyl group having 2 to 20 carbon atoms may be Z 2 The substituted aryl group having 6 to 20 carbon atoms may be Z 2 Substituted heteroaryl having 2 to 20 carbon atoms, R 50 Represents hydrogen atoms, which can be Z 1 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 1 Substituted alkenyl with 2 to 20 carbon atoms, which may be Z 1 The substituted alkynyl group having 2 to 20 carbon atoms may be Z 2 The substituted aryl group having 6 to 20 carbon atoms may be Z 2 Substituted heteroaryl having 2 to 20 carbon atoms, Z 1 Represents a halogen atom, nitro, cyano, diphenylamino, which can be Z 3 The substituted aryl group having 6 to 20 carbon atoms may be Z 3 Substituted heteroaryl having 2 to 20 carbon atoms, Z 2 Represents a halogen atom, nitro, cyano, diphenylamino, which can be Z 3 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z3 The substituted alkenyl group having 2 to 20 carbon atoms may be Z 3 Substituted alkynyl having 2 to 20 carbon atoms, Z 3 represents a halogen atom, a nitro group, a cyano group or a diphenylamino group. Specific examples of these halogen atoms, alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms and heteroaryl groups having 2 to 20 carbon atoms include the same groups as described above.

[0097] In particular, as R 5 ~R 25 、R 28 ~R 49 and R 51 ~R 194 , preferably a hydrogen atom, a fluorine atom, a cyano group, a diphenylamino group which may be substituted by a fluorine atom, an alkyl group having 1 to 20 carbon atoms which may be substituted by a fluorine atom, an aryl group having 6 to 20 carbon atoms which may be substituted by a fluorine atom, or a heteroaryl group having 2 to 20 carbon atoms which may be substituted by a fluorine atom; more preferably a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted by a fluorine atom, or a phenyl group which may be substituted by a fluorine atom; further preferably a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; and most preferably a hydrogen atom.

[0098] As R 26 and R 27 , preferably can be Z 2 The substituted aryl group having 6 to 14 carbon atoms may be Z 2 The substituted heteroaryl group having 2 to 14 carbon atoms may be more preferably Z 2 The substituted aryl group having 6 to 14 carbon atoms may be further preferably substituted by Z 2 Substituted phenyl, can be Z 2 Substituted 1-naphthyl, which may be Z 2 Substituted 2-naphthyl.

[0099] As R 50 , preferably hydrogen atoms, which can be Z 2 The substituted aryl group having 6 to 20 carbon atoms is preferably a hydrogen atom, which may be substituted by Z 2 The substituted aryl group having 6 to 14 carbon atoms is preferably a hydrogen atom, which may be Z 2 Substituted phenyl, can be Z 2 Substituted 1-naphthyl, which may be Z 2 Substituted 2-naphthyl.

[0100] In addition, Ar 4 Each independently represents an aryl group having 6 to 20 carbon atoms which may be substituted with a di(aryl group having 6 to 20 carbon atoms)amino group.

[0101] Specific examples of the aryl group having 6 to 20 carbon atoms include the same groups as described above. Specific examples of the di(aryl group having 6 to 20 carbon atoms)amino group include diphenylamino, 1-naphthylphenylamino, di(1-naphthyl)amino, 1-naphthyl-2-naphthylamino, and di(2-naphthyl)amino.

[0102] As Ar 4 , preferably phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl, p-(diphenylamino)phenyl, p-(1-naphthylphenylamino)phenyl, p-(di(1-naphthyl)amino)phenyl, p-(1-naphthyl-2-naphthylamino)phenyl, p-(di(2-naphthyl)amino)phenyl, more preferably p-(diphenylamino)phenyl.

[0103] The following are listed as Ar 0 Specific examples of preferred groups are shown below, but are not limited to these.

[0104] [Chemistry 12]

[0105]

[0106] (Wherein, DPA represents diphenylamino.)

[0107] [Chemistry 13]

[0108]

[0109] [Chemistry 14]

[0110]

[0111] [Chemistry 15]

[0112]

[0113] (Where R 50 Meanings the same as above.)

[0114] [Chemistry 16]

[0115]

[0116] [Chemistry 17]

[0117]

[0118] [Chemistry 18]

[0119]

[0120] [Chemistry 19]

[0121]

[0122] [Chemistry 20]

[0123]

[0124] In the present invention, R 50 Specific examples of the group include the following groups, but are not limited to these.

[0125] [Chemistry 21]

[0126]

[0127] [Chemistry 22]

[0128]

[0129] [Chemistry 23]

[0130]

[0131] [Chemistry 24]

[0132]

[0133] [Chemistry 25]

[0134]

[0135] [Chemistry 26]

[0136]

[0137] In the present invention, the carbon number of the alkyl group, alkenyl group, and alkynyl group is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less.

[0138] The carbon number of the aryl group and heteroaryl group is preferably 14 or less, more preferably 10 or less, and even more preferably 6 or less.

[0139] In the present invention, considering the ease of synthesis, the aniline derivative represented by formula (1) is preferably an aniline derivative represented by any one of formulae (1-1) to (1-4).

[0140] [Chemistry 27]

[0141]

[0142] (Ar 1 ~Ar 3 Different from each other, it is a group represented by any one of the above formulas (B1) to (B16), in each formula, Ar 1All represent the same group, Ar 2 All represent the same group, Ar 3 All represent the same group.)

[0143] The aniline derivative represented by formula (1) used in the present invention can be produced by reacting an amine compound represented by formula (4) with an aryl compound represented by formula (5) in the presence of a catalyst.

[0144] [Chemistry 28]

[0145]

[0146] (wherein, X represents a halogen atom or a pseudohalogen group, Ar 0 、Ph 1 and k have the same meanings as above.)

[0147] Examples of the halogen atom include the same halogen atoms as those mentioned above.

[0148] Examples of the pseudohalogen group include (fluoro)alkylsulfonyloxy groups such as methanesulfonyloxy, trifluoromethanesulfonyloxy, and nonafluorobutanesulfonyloxy; and aromaticsulfonyloxy groups such as benzenesulfonyloxy and toluenesulfonyloxy.

[0149] The feed ratio of the amine compound represented by formula (4) to the aryl compound represented by formula (5) is such that the aryl compound is an equivalent or more, preferably about 1 to 1.2 equivalents, relative to the amount of all NH groups of the amine compound.

[0150] Examples of the catalyst used in the above reaction include copper catalysts such as copper chloride, copper bromide, and copper iodide; palladium catalysts such as Pd(PPh3)4(tetrakis(triphenylphosphine)palladium), Pd(PPh3)2Cl2(bis(triphenylphosphine)palladium dichloride), Pd(dba)2(bis(dibenzylideneacetone)palladium), Pd2(dba)3(tris(dibenzylideneacetone)dipalladium), Pd(Pt-Bu3)2(bis(tri(tert-butylphosphine))palladium), and Pd(OAc)2(palladium acetate). These catalysts may be used alone or in combination of two or more. In addition, these catalysts may be used together with a known appropriate ligand.

[0151] Examples of such ligands include tertiary phosphines such as triphenylphosphine, tri-o-tolylphosphine, diphenylmethylphosphine, phenyldimethylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri-tert-butylphosphine, di-tert-butyl(phenyl)phosphine, di-tert-butyl(4-dimethylaminophenyl)phosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, and 1,1′-bis(diphenylphosphino)ferrocene; and triesters of phosphites such as trimethyl phosphite, triethyl phosphite, and triphenyl phosphite.

[0152] The amount of the catalyst used can be about 0.1 to 0.2 mol, preferably about 0.15 mol, per 1 mol of the aryl compound represented by formula (5).

[0153] When a ligand is used, the amount thereof used can be 0.1 to 5 equivalents, preferably 1 to 2 equivalents, based on the metal complex used.

[0154] In the case where the raw material compound is all solid or from the viewpoint of efficiently obtaining the target aniline derivative, each of the above reactions is carried out in a solvent. When a solvent is used, its type is not particularly limited as long as it does not have a negative effect on the reaction. As a specific example, aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decahydronaphthalene, etc.), halogenated aliphatic hydrocarbons (chloroform, dichloromethane, dichloroethane, carbon tetrachloride, etc.), aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.), halogenated aromatic hydrocarbons (chlorobenzene, bromobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, etc.), ethers (diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane , 1,2-diethoxyethane, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, cyclohexanone, etc.), amides (N,N-dimethylformamide, N,N-dimethylacetamide, etc.), lactams and lactones (N-methylpyrrolidone, γ-butyrolactone, etc.), ureas (N,N-dimethylimidazolidinone, tetramethylurea, etc.), sulfoxides (dimethyl sulfoxide, sulfolane, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.), etc. These solvents may be used alone or in combination of two or more.

[0155] The reaction temperature can be appropriately set within the range from the melting point to the boiling point of the solvent used, and is preferably approximately 0 to 200°C, more preferably 20 to 150°C.

[0156] After the reaction is completed, the target aniline derivative can be obtained by post-treatment according to conventional methods.

[0157] The aniline derivative represented by the above formula (1-1) can also be produced by the following method.

[0158] First, a dinitro compound represented by the formula (1-1-4) and an aryl compound represented by the formula (6) are reacted to obtain a dinitro compound represented by the formula (1-1-3).

[0159] [Chemistry 29]

[0160]

[0161] (where Ar 1 、Ph 1 , X and k have the same meanings as above.)

[0162] The feed ratio of the dinitro compound represented by formula (1-1-4) to the aryl compound represented by formula (6) is such that the aryl compound is an equivalent or more, preferably about 1 to 1.2 equivalents, relative to the amount of all NH groups of the dinitro compound.

[0163] The conditions for the coupling reaction, such as the amount of the catalyst relative to the aryl compound, the solvent, and the reaction temperature, are the same as those described above for the method for producing the aniline derivative represented by formula (1).

[0164] Next, the nitro group in the dinitro compound represented by formula (1-1-3) is reduced by hydrogenation to obtain the amine compound represented by formula (1-1-2). The hydrogenation reaction may be carried out using Pd / C or the like, and can be carried out using a known method.

[0165] [Chemistry 30]

[0166]

[0167] (where Ar 1 、Ph 1 and k have the same meanings as above.)

[0168] Secondly, the amine compound represented by formula (1-1-2) is reacted with the aromatic compound represented by formula (7) to obtain the amine compound represented by formula (1-1-1), and the obtained amine compound represented by formula (1-1-1) is reacted with the aromatic compound represented by formula (8) to obtain the aniline derivative represented by formula (1-1).

[0169] [Chemistry 31]

[0170]

[0171] (where Ar 1 、Ar 2 、Ar 3 、Ph 1, X and k have the same meanings as above.)

[0172] Regarding the feed ratio of the amine compound represented by formula (1-1-2) to the aromatic compound represented by formula (7) or the feed ratio of the amine compound represented by formula (1-1-1) to the aromatic compound represented by formula (8), the aromatic compound can be present in an amount of 2 equivalents or more, preferably about 2 to 2.4 equivalents, relative to the amine compound.

[0173] The conditions for the coupling reaction, such as the amount of the catalyst relative to the aryl compound, the solvent, and the reaction temperature, are the same as those described above for the production method of the aniline derivative represented by formula (1).

[0174] In addition, the aniline derivative represented by the formula (1-2) can also be produced by the following method.

[0175] The amine compound represented by the formula (1-1-1) obtained by the above-mentioned method is reacted with the aryl compound represented by the formula (6) to obtain the aniline derivative represented by the formula (1-2).

[0176] [Chemistry 32]

[0177]

[0178] (where Ar 1 、Ar 2 、Ph 1 , X and k have the same meanings as above.)

[0179] The coupling reaction conditions such as the feed ratio of the amine compound and the aryl compound, the amount of the catalyst relative to the aryl compound, the solvent, the reaction temperature, etc. are the same as those described above for the production method of the aniline derivative represented by formula (1).

[0180] In addition, the aniline derivative represented by the formula (1-3) can also be produced by the following method.

[0181] The amine compound represented by the formula (1-1-2) obtained by the above-mentioned method is reacted with the aryl compound represented by the formula (7) to obtain the aniline derivative represented by the formula (1-3).

[0182] [Chemistry 33]

[0183]

[0184] (where Ar 1 、Ar 2 、Ph 1 , X and k have the same meanings as above.)

[0185] The feed ratio of the amine compound represented by formula (1-1-2) to the aryl compound represented by formula (7) is such that the aryl compound is an equivalent or more, preferably about 1 to 1.2 equivalents, relative to the amount of all NH groups of the amine compound.

[0186] The conditions for the coupling reaction, such as the amount of the catalyst relative to the aryl compound, the solvent, and the reaction temperature, are the same as those described above for the method for producing the aniline derivative represented by formula (1).

[0187] In addition, the aniline derivative represented by the formula (1-4) can also be produced by the following method.

[0188] By reacting the amine compound represented by the formula (4) with the aryl compound represented by the formula (6), the aniline derivative represented by the formula (1-4) can be obtained.

[0189] [Chemistry 34]

[0190]

[0191] (where Ar 1 、Ph 1 , X and k have the same meanings as above.)

[0192] The coupling reaction conditions such as the feed ratio of the amine compound and the aryl compound, the amount of the catalyst relative to the aryl compound, the solvent, the reaction temperature, etc. are the same as those described above for the production method of the aniline derivative represented by formula (1).

[0193] Furthermore, as shown in the following scheme, the amine compound that can be used as a raw material for the aniline derivative used in the present invention can be obtained by (A) a coupling reaction of an amine compound represented by formula (1-1-4) or formula (1-1-5) with an aryl compound represented by formula (9) and (B) a reduction reaction of a hydrogenated nitro group. By repeating these (A) and (B), the chain length (the number of meta- or para-phenylene groups) can be increased.

[0194] [Chemistry 35]

[0195]

[0196] (where Ph 1 , X and k have the same meanings as above.)

[0197] [Chemistry 36]

[0198]

[0199] (where Ph 1 , X and k have the same meanings as above.)

[0200] To give a more specific example, one of the amine compounds included in formula (4) can be obtained by (A) a coupling reaction of m-phenylenediamine or 3-nitroaniline with 3-halonitrobenzene and (B) a reduction reaction using a hydrogenated nitro group, as shown in the following scheme. By repeating the reactions (A) and (B), the chain length (the number of m-phenylene groups) can be increased.

[0201] [Chemistry 37]

[0202] Odd-numbered phenylene groups

[0203] Even-numbered phenylene groups

[0204]

[0205] (In the formula, X has the same meaning as above.)

[0206] By selecting the upper reaction and the lower reaction of the above scheme respectively, the even and odd numbers of phenylene groups can be produced. Therefore, without using a synthetically difficult method such as protecting one amino group with a protecting group, the amine compound represented by formula (4) having the desired number of phenylene groups can be freely produced.

[0207] In this case, as for the feed ratio of the amine compound represented by formula (1-1-4) or metaphenylenediamine to the aromatic compound represented by formula (9) or 3-halonitrobenzene, expressed as a mass ratio, the aromatic compound represented by formula (9) or 3-halonitrobenzene is preferably about 2 to 2.4 relative to 1 of the amine compound represented by formula (1-1-4) or metaphenylenediamine.

[0208] In addition, with respect to the feed ratio of the amine compound represented by formula (1-1-5) or 3-nitroaniline to the aromatic compound represented by formula (9) or 3-halonitrobenzene, expressed as a mass ratio, the aromatic compound represented by formula (9) or 3-halonitrobenzene is preferably about 1 to 1.2 relative to 1 of the amine compound represented by formula (1-1-5) or 3-nitroaniline.

[0209] Furthermore, as the palladium catalyst used for the coupling reaction, the same palladium catalyst as mentioned above can be cited. In addition, in this case, a ligand can also be used. As the ligand, in addition to the ligands exemplified above, biphenylphosphine compounds such as JohnPhos, CyjohnPhos, DavePhos, XPhos, SPhos, tBuXPhos, RuPhos, Me4tBuXPhos, sSPhos, tBuMePhos, MePhos, tBuDavePhos, PhDavePhos, 2'-dicyclohexylphosphino-2,4,6-trimethoxybiphenyl, BrettPhos, tBuBrettPhos, AdBrettPhos, Me3(OMe)tBuXPhos, (2-biphenyl)di-1-adamantylphosphine, RockPhos, and CPhos commercially available from Aldrich can also be preferably used.

[0210] Examples of the base used in the coupling reaction include alkali metal elements such as lithium, sodium, potassium, lithium hydride, sodium hydride, lithium hydroxide, potassium hydroxide, tert-butoxylithium, tert-butoxysodium, tert-butoxypotassium, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; alkali metal hydrides, alkali metal hydroxides, alkali metal alkoxides, alkali metal carbonates, and alkali metal bicarbonates; alkaline earth metal carbonates such as calcium carbonate; organic lithiums such as n-butyllithium, sec-butyllithium, tert-butyllithium, lithium diisopropylamine (LDA), lithium 2,2,6,6-tetramethylpiperidinium (LiTMP), and lithium hexamethyldisilazane (LHMDS); and amines such as triethylamine, diisopropylethylamine, tetramethylethylenediamine, triethylenediamine, and pyridine.

[0211] The conditions for the coupling reaction, such as the solvent and the reaction temperature, are the same as those described above for the method for producing the aniline derivative represented by the formula (1).

[0212] The hydrogenation reaction using Pd / C can be performed by a known method.

[0213] Furthermore, when p-phenylene is introduced in place of m-phenylene, 4-halonitrobenzene can be used in place of 3-halonitrobenzene.

[0214] The charge-transporting varnish of the present invention comprises a charge-transporting substance containing the above-mentioned aniline derivative and an organic solvent, and may contain a dopant substance for the purpose of improving the charge transporting ability of the obtained thin film, depending on the application of the film.

[0215] The dopant substance is not particularly limited as long as it is soluble in at least one solvent used in the varnish, and both inorganic and organic dopant substances can be used.

[0216] Inorganic and organic dopant substances may be used alone or in combination of two or more.

[0217] Furthermore, the dopant substance may be a substance that, in the process of obtaining a charge transport thin film as a solid film from a varnish, causes a portion of the molecule to be released due to an external stimulus such as heating during firing, thereby initially manifesting or enhancing the function as a dopant substance, such as an aryl sulfonate compound protected with a group that allows the sulfonic acid group to be easily released.

[0218] In particular, in the present invention, heteropolyacids are preferred as inorganic dopant substances.

[0219] Heteropolyacids are typically represented by a Keggin-type chemical structure represented by formula (H1) or a Dawson-type chemical structure represented by formula (H2), in which a heteroatom is located at the center of the molecule. They are polyacids formed by condensing an isopolyacid of an oxyacid of vanadium (V), molybdenum (Mo), tungsten (W), or the like with an oxyacid of a different element. Examples of such oxyacids of a different element include oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

[0220] [Chemistry 38]

[0221]

[0222] As the specific example of heteropolyacid, can enumerate phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, phosphotungstomolybdic acid etc., these heteropolyacids can be used alone, also can be used in combination of 2 or more.Have again, these heteropolyacids can be used as commercially available product and obtain, in addition, also can adopt known method to synthesize.

[0223] In particular, when one heteropoly acid is used, the preferred heteropoly acid is phosphotungstic acid or phosphomolybdic acid, and the most preferred heteropoly acid is phosphotungstic acid. In addition, when two or more heteropoly acids are used, one of the two or more heteropoly acids is preferably phosphotungstic acid or phosphomolybdic acid, and the most preferred heteropoly acid is phosphotungstic acid.

[0224] In addition, the heteropolyacid can be used in the present invention even if the number of elements in the structure represented by the general formula is greater or less in quantitative analysis such as elemental analysis, as long as it is a commercially available product or a product appropriately synthesized according to a known synthesis method.

[0225] That is, for example, phosphotungstic acid is generally represented by the chemical formula H3(PW 12 O 40 )·nH2O, phosphomolybdic acid is represented by the chemical formula H3(PMo 12 O 40)·nH2O represents that, in quantitative analysis, even if the number of P (phosphorus), O (oxygen), W (tungsten), or Mo (molybdenum) in the formula is large or small, as long as it is a commercially available product or a product appropriately synthesized according to a known synthesis method, it can be used in the present invention. In this case, the mass of the heteropolyacid specified in the present invention is not the mass of pure phosphotungstic acid in the synthetic product or commercial product (phosphotungstic acid content), but means the total mass in a state including hydrated water and other impurities in a form available as a commercial product or a form that can be separated using a known synthesis method.

[0226] The amount of the heteropolyacid used can be about 0.001 to 50.0, preferably about 0.01 to 20.0, and more preferably about 0.1 to 10.0, expressed as a mass ratio, relative to the charge transporting material 1 comprising the aniline derivative represented by formula (1).

[0227] On the other hand, as the organic dopant substance, in particular, tetracyanoquinodimethane derivatives and benzoquinone derivatives can be used.

[0228] Specific examples of the tetracyanoquinodimethane derivative include 7,7,8,8-tetracyanoquinodimethane (TCNQ) and halogenated tetracyanoquinodimethane represented by the formula (H3).

[0229] Specific examples of benzoquinone derivatives include tetrafluoro-1,4-benzoquinone (F4BQ), tetrachloro-1,4-benzoquinone (tetrachloro-p-benzoquinone), tetrabromo-1,4-benzoquinone, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ).

[0230] [Chemistry 39]

[0231]

[0232] Where R 500 ~R 503 Each independently represents a hydrogen atom or a halogen atom, at least one is a halogen atom, preferably at least two are halogen atoms, more preferably at least three are halogen atoms, and most preferably all are halogen atoms.

[0233] Examples of the halogen atom include the same halogen atoms as mentioned above, preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

[0234] Specific examples of such halogenated tetracyanoquinodimethanes include 2-fluoro-7,7,8,8-tetracyanoquinodimethane, 2-chloro-7,7,8,8-tetracyanoquinodimethane, 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane, 2,5-dichloro-7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetrachloro-7,7,8,8-tetracyanoquinodimethane, and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ).

[0235] The amount of the tetracyanoquinodimethane derivative and the benzoquinone derivative used is preferably 0.0001 to 100 equivalents, more preferably 0.01 to 50 equivalents, and even more preferably 1 to 20 equivalents relative to the aniline derivative represented by formula (1).

[0236] Specific examples of the arylsulfonic acid compound include benzenesulfonic acid, toluenesulfonic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, dihexylbenzenesulfonic acid, 2,5-dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7-dibutyl-2-naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3-dodecyl-2-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 4-hexyl-1-naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, Sulfonic acid, 7-hexyl-1-naphthalenesulfonic acid, 6-hexyl-2-naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, 2,7-dinonyl-4-naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, 2,7-dinonyl-4,5-naphthalenedisulfonic acid, 1,4-benzodioxanedisulfonic acid compounds described in International Publication No. 2005 / 000832, arylsulfonic acid compounds described in International Publication No. 2006 / 025342, arylsulfonic acid compounds described in International Publication No. 2009 / 096352, etc.

[0237] Preferred examples of the arylsulfonic acid compound include arylsulfonic acid compounds represented by formula (H4) or (H5).

[0238] [Chemistry 40]

[0239]

[0240] A 1 represents O or S, preferably O.

[0241] A 2 represents a naphthalene ring or an anthracene ring, preferably a naphthalene ring.

[0242] A 3 represents a 2- to 4-valent perfluorobiphenyl group, and p represents A 1 With A 3 The binding number of A is an integer satisfying 2≤p≤4. 3is a perfluorobiphenylene group, preferably a perfluorobiphenyl-4,4′-diyl group, and p is 2.

[0243] q represents the same as A 2 The number of sulfonic acid groups bonded is an integer satisfying 1≤q≤4, and 2 is most preferred.

[0244] A 4 ~A 8 Each independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, or a haloalkenyl group having 2 to 20 carbon atoms, 4 ~A 8 At least three of them are halogen atoms.

[0245] Examples of the haloalkyl group having 1 to 20 carbon atoms include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, and 1,1,2,2,3,3,4,4,4-nonafluorobutyl.

[0246] Examples of the haloalkenyl group having 2 to 20 carbon atoms include perfluorovinyl, perfluoropropenyl (perfluoroallyl), and perfluorobutenyl.

[0247] Examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms include the same groups as described above. As the halogen atom, a fluorine atom is preferred.

[0248] Among these, A is preferred 4 ~A 8 is a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, or a haloalkenyl group having 2 to 10 carbon atoms, and A 4 ~A 8 At least three of them are fluorine atoms, more preferably hydrogen atoms, fluorine atoms, cyano groups, alkyl groups having 1 to 5 carbon atoms, fluoroalkyl groups having 1 to 5 carbon atoms, or fluoroalkenyl groups having 2 to 5 carbon atoms, and A 4 ~A 8 At least three of them are fluorine atoms, more preferably hydrogen atoms, fluorine atoms, cyano groups, perfluoroalkyl groups having 1 to 5 carbon atoms, or perfluoroalkenyl groups having 1 to 5 carbon atoms, and A 4 、A 5 and A 8 is a fluorine atom.

[0249] The term "perfluoroalkyl" refers to a group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms, and the term "perfluoroalkenyl" refers to a group in which all hydrogen atoms of an alkenyl group are substituted with fluorine atoms.

[0250] r represents the number of sulfonic acid groups bonded to the naphthalene ring and is an integer satisfying 1≤r≤4, preferably 2 to 4, and most preferably 2.

[0251] The molecular weight of the arylsulfonic acid compound used as a dopant substance is not particularly limited, but is preferably 2000 or less, more preferably 1500 or less, in consideration of solubility in an organic solvent when used together with the aniline derivative used in the present invention.

[0252] Specific examples of preferred arylsulfonic acid compounds are listed below, but the compounds are not limited to these.

[0253] [Chemistry 41]

[0254]

[0255] The amount of the arylsulfonic acid compound used is preferably about 0.01 to 20.0, more preferably about 0.4 to 5.0, relative to the aniline derivative 1 represented by formula (1), expressed as a molar ratio.

[0256] As the arylsulfonic acid compound, a commercially available product may be used, or the arylsulfonic acid compound may be synthesized by a known method described in International Publication No. 2006 / 025342, International Publication No. 2009 / 096352, and the like.

[0257] On the other hand, examples of the arylsulfonate compound include the arylsulfonate compounds disclosed in International Publication No. 2017 / 217455, the arylsulfonate compounds disclosed in International Publication No. 2017 / 217457, and the arylsulfonate compounds described in Japanese Patent Application No. 2017-243631. Specifically, the arylsulfonate compound represented by any one of the following formulas (H6) to (H8) is preferred.

[0258] [Chemistry 42]

[0259]

[0260] (In the formula, m is an integer satisfying 1≤m≤4, preferably 2. n is an integer satisfying 1≤n≤4, preferably 2.)

[0261] In formula (H6), A 11 It is an m-valent group derived from perfluorobiphenyl.

[0262] A 12 It is -O- or -S-, preferably -O-.

[0263] A 13 It is a (n+1)-valent group derived from naphthalene or anthracene, and is preferably a group derived from naphthalene.

[0264] R s1 ~R s4 are each independently a hydrogen atom, or a linear or branched alkyl group having 1 to 6 carbon atoms, R s5 It is a monovalent hydrocarbon group having 2 to 20 carbon atoms which may be substituted.

[0265] Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-hexyl. An alkyl group having 1 to 3 carbon atoms is preferred.

[0266] The monovalent hydrocarbon group having 2 to 20 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include alkyl groups such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl; and aryl groups such as phenyl, naphthyl, and phenanthrenyl.

[0267] In particular, R s1 ~R s4 Among them, R is preferred s1 or R s3 is a straight-chain alkyl group having 1 to 3 carbon atoms, the remainder being hydrogen atoms, or R s1 is a straight-chain alkyl group with 1 to 3 carbon atoms, R s2 ~R s4 In this case, the linear alkyl group having 1 to 3 carbon atoms is preferably a methyl group.

[0268] In addition, as R s5 , preferably a straight-chain alkyl group having 2 to 4 carbon atoms or a phenyl group.

[0269] In formula (H7), A 14 It is an m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, which may be substituted, and is obtained by removing m hydrogen atoms from a hydrocarbon compound having 6 to 20 carbon atoms and containing one or more aromatic rings.

[0270] Examples of such hydrocarbon compounds include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, and phenanthrene.

[0271] Furthermore, with respect to the above-mentioned hydrocarbon group, a part or all of its hydrogen atoms may be further substituted by a substituent, and examples of such substituents include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a hydroxyl group, an amino group, a silanol group, a thiol group, a carboxyl group, a sulfonate group, a phosphoric acid group, a phosphate ester group, an ester group, a thioester group, an acylamino group, a monovalent hydrocarbon group, an organic oxy group, an organic amino group, an organic silyl group, an organic thio group, an acyl group, and a sulfonic acid group.

[0272] Among these, as A 14 , preferably a group derived from benzene, biphenyl, etc.

[0273] In addition, A 15 It is -O- or -S-, preferably -O-.

[0274] A 16 An (n+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, wherein 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.

[0275] Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene.

[0276] Among them, as A 16 , preferably a group derived from naphthalene or anthracene, more preferably a group derived from naphthalene.

[0277] 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. s6 、R s7 and R s8 The total number of carbon atoms in R is 6 or more. s6 、R s7 and R s8 The upper limit of the total number of carbon atoms is not particularly limited, but is preferably 20 or less, and more preferably 10 or less.

[0278] Specific examples of the above-mentioned linear or branched monovalent aliphatic hydrocarbon groups include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, and decyl; and alkenyl groups having 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and hexenyl.

[0279] Among these, R s6 Preferably, a hydrogen atom, R s7 and R s8 Each independently preferably has an alkyl group having 1 to 6 carbon atoms.

[0280] In formula (H8), R s9 ~R s13 Each is independently a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, or a haloalkenyl group having 2 to 10 carbon atoms.

[0281] The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl.

[0282] The haloalkyl group having 1 to 10 carbon atoms is not particularly limited as long as a part or all of the hydrogen atoms of the above-mentioned alkyl group having 1 to 10 carbon atoms are substituted with halogen atoms. Specific examples thereof include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, and 1,1,2,2,3,3,4,4,4-nonafluorobutyl.

[0283] The haloalkenyl 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 perfluorovinyl, perfluoro-1-propenyl, perfluoro-2-propenyl, perfluoro-1-butenyl, perfluoro-2-butenyl, and perfluoro-3-butenyl.

[0284] Among these, R s9 , preferably nitro, cyano, a haloalkyl group having 1 to 10 carbon atoms, or a haloalkenyl group having 2 to 10 carbon atoms, more preferably nitro, cyano, a haloalkyl group having 1 to 4 carbon atoms, or a haloalkenyl group having 2 to 4 carbon atoms, further preferably nitro, cyano, trifluoromethyl, or perfluoropropenyl.

[0285] As R s10 ~R s13 , preferably a halogen atom, more preferably a fluorine atom.

[0286] A 17 It is -O-, -S- or -NH-, preferably -O-.

[0287] A 18 An (n+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, wherein 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.

[0288] Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene.

[0289] Among them, as A 18 , preferably a group derived from naphthalene or anthracene, more preferably a group derived from naphthalene.

[0290] R s14 ~R s17 Each independently represents a hydrogen atom, or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms.

[0291] Specific examples of the monovalent aliphatic hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl; and alkenyl groups having 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and hexenyl. Alkyl groups having 1 to 20 carbon atoms are preferred, alkyl groups having 1 to 10 carbon atoms are more preferred, and alkyl groups having 1 to 8 carbon atoms are still more preferred.

[0292] R s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or OR s19 . R s19 It is a monovalent hydrocarbon group having 2 to 20 carbon atoms which may be substituted.

[0293] As R s18 Examples of the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms include the same groups as those mentioned above.

[0294] In R s18 When it is a monovalent aliphatic hydrocarbon group, R s18 An alkyl group having 1 to 20 carbon atoms is preferred, an alkyl group having 1 to 10 carbon atoms is more preferred, and an alkyl group having 1 to 8 carbon atoms is further preferred.

[0295] As R s19 The monovalent hydrocarbon group having 2 to 20 carbon atoms includes, in addition to the groups other than the methyl group among the monovalent aliphatic hydrocarbon groups mentioned above, aryl groups such as phenyl, naphthyl, and phenanthrenyl.

[0296] Among them, R s19 A linear alkyl group having 2 to 4 carbon atoms or a phenyl group is preferred.

[0297] 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.

[0298] Specific examples of preferred arylsulfonic acid ester compounds include the following, but are not limited to these.

[0299] [Chemistry 43]

[0300]

[0301] In the present invention, considering the ability to obtain a thin film with high charge transport properties with good reproducibility and the ease of obtaining the dopant substance, it is preferred to use at least one of an arylsulfonic acid compound, an arylsulfonic ester compound, an onium borate, a halogenated tetracyanoquinodimethane, and a quinone derivative as the dopant substance. In considering the ability to obtain a thin film with a high refractive index, it is more preferred to use an arylsulfonic ester compound.

[0302] In the present invention, the amount of the dopant substance in the varnish is preferably about 0.01 to 20, more preferably about 0.05 to 15, relative to the aniline derivative 1 represented by formula (1), expressed as a molar ratio.

[0303] In addition, in the charge-transporting varnish of the present invention, other known charge-transporting substances can be used in addition to the above-mentioned charge-transporting substance composed of an aniline derivative.

[0304] Furthermore, when the obtained thin film is used as a hole injection layer of an organic EL element, the charge transporting varnish may contain an organic silane compound for the purpose of improving the injectability into the hole transport layer and improving the life characteristics of the element, and the content of the organic silane compound is generally about 1 to 30% by mass relative to the total mass of the charge transporting substance and the dopant substance.

[0305] The organic solvent used in preparing the charge transport varnish of the present invention is not particularly limited as long as it can dissolve the charge transport material and the dopant material, and both high-polarity solvents and low-polarity solvents can be used. It should be noted that in the present invention, the so-called low-polarity solvent refers to a solvent having a relative dielectric constant of less than 7 at a frequency of 100 kHz, and the so-called high-polarity solvent is defined as a solvent having a relative dielectric constant of 7 or more at a frequency of 100 kHz. Furthermore, as needed, multiple high-polarity solvents and low-polarity solvents can also be mixed.

[0306] In particular, when the aniline derivative as a charge transporting substance has a primary or secondary arylamine structure in its skeleton, by using at least one high-polarity solvent, and when the aniline derivative as a charge transporting substance does not have a primary or secondary arylamine structure in its skeleton, by using at least one low-polarity solvent, a charge transporting varnish with excellent uniformity can be obtained with good reproducibility.

[0307] Examples of low polarity solvents include

[0308] Chloroform, chlorobenzene and other chlorine-based solvents;

[0309] Aromatic hydrocarbon solvents such as toluene, xylene, tetralin, cyclohexylbenzene, decylbenzene and other alkylbenzenes;

[0310] Aliphatic alcohol solvents such as 1-octanol, 1-nonanol, and 1-decanol;

[0311] Ether solvents such as tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, and triethylene glycol butyl methyl ether;

[0312] Ester solvents such as methyl benzoate, ethyl benzoate, butyl benzoate, isoamyl benzoate, di(2-ethylhexyl) phthalate, dibutyl maleate, dibutyl oxalate, hexyl acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate.

[0313] In addition, examples of highly polar solvents include

[0314] Amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone;

[0315] Ketone solvents such as ethyl methyl ketone, isophorone, and cyclohexanone;

[0316] Cyano-based solvents such as acetonitrile and 3-methoxypropionitrile;

[0317] Polyol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, and 2,3-butanediol;

[0318] Monovalent alcohol solvents other than aliphatic alcohols such as diethylene glycol monomethyl ether, diethylene glycol monophenyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, benzyl alcohol, 2-phenoxyethanol, 2-benzyloxyethanol, 3-phenoxybenzyl alcohol, and tetrahydrofurfuryl alcohol;

[0319] Sulfoxide solvents such as dimethyl sulfone;

[0320] etc.

[0321] Furthermore, by including in the varnish at least one high-viscosity organic solvent having a viscosity of 10 to 200 mPa·s, particularly 35 to 150 mPa·s, at 25°C and a boiling point of 50 to 300°C, particularly 150 to 250°C, at normal pressure (atmospheric pressure), the viscosity of the varnish can be easily adjusted. As a result, it is possible to obtain a highly flat film with good reproducibility and adjust the varnish to suit the coating method used.

[0322] Examples of high-viscosity organic solvents include, but are not limited to, cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, propylene glycol, and hexylene glycol. These solvents may be used alone or in combination of two or more.

[0323] The addition ratio of the high-viscosity organic solvent to the total solvent used in the varnish is preferably within a range where solids do not precipitate. As long as solids do not precipitate, the addition ratio is preferably 5 to 80% by mass.

[0324] Furthermore, for the purpose of improving wettability to the substrate, adjusting the surface tension of the solvent, adjusting the polarity, adjusting the boiling point, etc., other solvents may be mixed in a ratio of 1 to 90% by mass, preferably 1 to 50% by mass, relative to the total solvent used in the varnish.

[0325] Examples of such solvents include, but are not limited to, propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, and n-hexyl acetate. These solvents may be used alone or in combination of two or more.

[0326] In addition, when the aniline derivative used in the present invention does not have an NH structure in the molecule, such as when it has a substituent on the nitrogen atom at the 9-position of carbazole, and preferably has substituents on all nitrogen atoms, it becomes easy to prepare a varnish using only the low-polarity solvent shown below.

[0327] Specific examples of low-polarity solvents include chlorine-based solvents such as chloroform and chlorobenzene; aromatic hydrocarbon-based solvents such as toluene, xylene, tetralin, cyclohexylbenzene, and decylbenzene; aliphatic alcohol-based solvents such as 1-octanol, 1-nonanol, and 1-decanol; ether-based solvents such as tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, and triethylene glycol butyl methyl ether; and ester-based solvents such as methyl benzoate, ethyl benzoate, butyl benzoate, isoamyl benzoate, di(2-ethylhexyl) phthalate, dibutyl maleate, dibutyl oxalate, hexyl acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate. These solvents may be used alone or in combination of two or more.

[0328] In addition, the solid content concentration of the charge transport varnish is appropriately set in consideration of the viscosity and surface tension of the varnish, the thickness of the film to be produced, etc., and is usually about 0.1 to 10.0 mass%. If consideration is given to improving the coating properties of the varnish, it is preferably about 0.5 to 5.0 mass%, and more preferably about 1.0 to 3.0 mass%.

[0329] The viscosity of the charge transport varnish of the present invention is appropriately determined depending on the thickness of the film to be produced and the solid content concentration, and is usually 1 to 50 mPa·s at 25°C. The surface tension is usually 20 to 50 mN / m at 25°C.

[0330] The viscosity and surface tension of the charge transport varnish of the present invention can be adjusted by changing the type of organic solvent used, their ratio, solid content concentration, etc., taking into account various factors such as the coating method used and the desired film thickness.

[0331] In addition, in the present invention, the solid content means components other than the solvent.

[0332] In the present invention, the method for preparing the charge transport varnish is not particularly limited. Examples thereof include a method of dissolving the above-mentioned aniline derivative in a portion of the solvent used and adding the remaining solvent thereto; a method of first mixing all of the solvents used and dissolving the above-mentioned aniline derivative therein, etc.

[0333] When preparing the charge transport varnish of the present invention, from the viewpoint of obtaining a thin film with higher flatness with good reproducibility, the charge transport material, dopant substance, etc. are dissolved in an organic solvent and then preferably filtered using a submicron filter or the like.

[0334] Furthermore, if necessary, the varnish may be heated to such an extent that the components thereof do not deteriorate.

[0335] By using the charge-transporting varnish of the present invention described above, a charge-transporting thin film can be easily produced, and thus it can be suitably used in the production of electronic devices, particularly organic EL devices.

[0336] In this case, the charge-transporting thin film can be formed by applying the charge-transporting varnish of the present invention on a substrate and firing the coating.

[0337] The coating method of the varnish is not particularly limited, and examples thereof include dipping, spin coating, transfer printing, roller coating, brush coating, inkjet coating, spray coating, and slit coating. The viscosity and surface tension of the varnish are preferably adjusted according to the coating method.

[0338] In addition, there is no particular limitation on the firing atmosphere of the charge-transporting varnish after coating. Not only in the air atmosphere, but also in an inert gas such as nitrogen or in a vacuum, a thin film with a uniform film-forming surface and high charge-transporting properties can be obtained. Depending on the type of dopant substance used together with the aniline derivative, by firing the varnish in the air atmosphere, a thin film with charge-transporting properties can sometimes be obtained with good reproducibility.

[0339] As for the firing temperature, it is appropriately set within the range of about 100 to 260°C, taking into account the purpose of the obtained film, the degree of charge transport properties imparted to the obtained film, the type of solvent, the boiling point, etc. When the obtained film is used as a hole injection layer of an organic EL element, it is preferably about 140 to 250°C, and more preferably about 145 to 240°C. For the charge transport varnish of the present invention, even low-temperature firing below 200°C can obtain a film with good charge transport properties.

[0340] During firing, temperature changes in two or more stages may be applied for the purpose of achieving more uniform film formation or promoting reaction on the substrate. Heating can be performed using appropriate equipment such as a hot plate or an oven.

[0341] The thickness of the charge-transporting thin film is not particularly limited. When used as a hole injection layer, hole transport layer, or hole injection transport layer of an organic EL device, it is generally 3 to 300 nm, preferably 5 to 200 nm. Methods for varying the film thickness include changing the solids concentration in the varnish or varying the amount of solution applied to the substrate during coating.

[0342] The organic EL device of the present invention has a pair of electrodes and a charge transport layer composed of the above-mentioned charge transport thin film of the present invention between these electrodes.

[0343] As a representative structure of an organic EL element, the following (a) to (f) can be listed, but it is not limited to these. It should be noted that in the following structure, as needed, an electron blocking layer can be provided between the light-emitting layer and the anode, and a hole blocking layer can be provided between the light-emitting layer and the cathode. In addition, the hole injection layer, the hole transport layer or the hole injection transport layer can have the function of an electron blocking layer, and the electron injection layer, the electron transport layer or the electron injection transport layer can have the function of a hole blocking layer. Furthermore, as needed, any functional layer can also be provided between the layers.

[0344] (a) Anode / HOL injection layer / HOT transport layer / Emission layer / Electron transport layer / Electron injection layer / Cathode

[0345] (b) Anode / hole injection layer / hole transport layer / light-emitting layer / electron injection transport layer / cathode

[0346] (c) Anode / HIT / Emission Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0347] (d) Anode / HIT / Emission Layer / Electron Injection / Cathode

[0348] (e) Anode / HIL / HTL / EML / Cathode

[0349] (f) Anode / HIT / Emitting Layer / Cathode

[0350] "Hole injection layer," "hole transport layer," and "hole injection and transport layer" are layers formed between the light-emitting layer and the anode, and have the function of transporting holes from the anode to the light-emitting layer. When only one layer of hole-transporting material is provided between the light-emitting layer and the anode, it is the "hole injection and transport layer." When two or more layers of hole-transporting material are provided between the light-emitting layer and the anode, the layer closest to the anode is the "hole injection layer," and the remaining layers are the "hole transport layers." In particular, a thin film that is excellent not only in accepting holes from the anode but also in injecting holes into the hole transport (light-emitting) layer is used for the hole injection (transport) layer.

[0351] The "electron injection layer", "electron transport layer" and "electron injection transport layer" are layers formed between the light-emitting layer and the cathode, and have the function of transporting electrons from the cathode to the light-emitting layer. When only one layer of electron transport material is set between the light-emitting layer and the cathode, it is the "electron injection transport layer". When two or more layers of electron transport material are set between the light-emitting layer and the cathode, the layer close to the cathode is the "electron injection layer" and the layers other than the cathode are the "electron transport layer".

[0352] The "light-emitting layer" is an organic layer that emits light. In doping systems, it comprises a host material and a dopant material. In this case, the host material primarily promotes the recombination of electrons and holes, confining excitons within the light-emitting layer, while the dopant material enables the excitons generated by the recombination to emit light efficiently. In phosphorescent devices, the host material primarily confines excitons generated by the dopant within the light-emitting layer.

[0353] The charge transporting film made from the charge transporting varnish containing the above-mentioned aniline derivative used in the present invention can be used as a functional layer provided between the anode and the light-emitting layer in an organic EL element, such as a hole injection layer, a hole transport layer, or a hole injection transport layer, and is preferably used as a hole injection layer.

[0354] Examples of materials and production methods for producing an organic EL device using the charge-transporting varnish containing the aniline derivative used in the present invention include the following, but are not limited thereto.

[0355] An example of a method for producing an OLED device having a hole injection layer composed of a thin film obtained from the charge-transporting varnish is described below. Furthermore, the electrodes are preferably pre-cleaned with alcohol, pure water, or the like, to the extent that they do not adversely affect the electrodes, and surface treated with UV ozone treatment, oxygen plasma treatment, or the like.

[0356] On the anode substrate, the above-mentioned method is adopted to form a hole injection layer using the above-mentioned charge transport varnish. It is introduced into a vacuum evaporation device, and a hole transport layer, a light-emitting layer, an electron transport layer / hole blocking layer, an electron injection layer, and a cathode metal are sequentially evaporated. Alternatively, in this method, instead of forming a hole transport layer and a light-emitting layer by evaporation, a hole transport layer forming composition comprising a hole transport polymer and a light-emitting layer forming composition comprising a light-emitting polymer are used to form these layers by a wet method. Furthermore, as needed, an electron blocking layer can be provided between the light-emitting layer and the hole transport layer.

[0357] Anode materials include transparent electrodes such as indium tin oxide (ITO) and indium zinc oxide (IZO), metal anodes made of metals such as aluminum, or alloys thereof, preferably those that have been planarized. Polythiophene derivatives and polyaniline derivatives with high charge transport properties can also be used.

[0358] In addition, examples of other metals constituting the metal anode include gold, silver, copper, indium, and alloys thereof.

[0359] Examples of materials for forming the hole transport layer include (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spirodimer, N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-benzidine (α-NPD), 4,4',4"-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), 4,4',4"-tris[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA), and other triarylamines; and oligothiophenes such as 5,5"-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2"-terthiophene (BMA-3T).

[0360] Examples of materials for forming the light-emitting layer include low-molecular-weight light-emitting materials such as metal complexes such as an aluminum complex of 8-hydroxyquinoline, metal complexes of 10-hydroxybenzo[h]quinoline, bis(vinylbenzene) derivatives, bis(vinylarylene) derivatives, metal complexes of (2-hydroxyphenyl)benzothiazole, and silole derivatives; and systems in which a light-emitting material and an electron-transferring material are mixed in polymer compounds such as poly(p-phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly(3-alkylthiophene), and polyvinylcarbazole.

[0361] In addition, when the light-emitting layer is formed by vapor deposition, it can be co-evaporated with a light-emitting dopant. Examples of the light-emitting dopant include metal complexes such as tris(2-phenylpyridine)iridium(III) (Ir(ppy)3), tetracene derivatives such as rubrene, quinacridone derivatives, and condensed polycyclic aromatic rings such as perylene.

[0362] Examples of the material forming the electron transport layer / hole blocking layer include oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

[0363] Examples of materials forming the electron injection layer include metal oxides such as lithium oxide (Li2O), magnesium oxide (MgO), and aluminum oxide (Al2O3), and metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF), but are not limited thereto.

[0364] Examples of the cathode material include aluminum, magnesium-silver alloys, and aluminum-lithium alloys.

[0365] Examples of the material forming the electron blocking layer include tris(phenylpyrazole)iridium and the like.

[0366] Examples of hole transport polymers include poly[(9,9-dihexylfluorene-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], poly[(9,9-dioctylfluorene-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,1'-biphenylene-4,4-diamine)], poly[(9,9-bis{1'-pentene -5'-yl}fluorene-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] terminated with polysilsesquioxane, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)], etc.

[0367] Examples of the light-emitting polymer include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), polyphenylenevinylene derivatives such as poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

[0368] The materials constituting the anode and cathode and the layers formed therebetween differ depending on whether a device having a bottom emission structure or a top emission structure is to be manufactured. Therefore, the materials are appropriately selected in consideration of this.

[0369] Typically, in a bottom-emission structure element, a transparent anode is used on the substrate side to extract light from the substrate side, while in a top-emission structure element, a reflective anode made of metal is used to extract light from the transparent electrode (cathode) side located in the opposite direction of the substrate. Therefore, for example, with respect to the anode material, when manufacturing a bottom-emission structure element, a transparent anode such as ITO is used, and when manufacturing a top-emission structure element, a reflective anode such as Al / Nd is used.

[0370] The organic EL element of the present invention is sealed with a water-scavenging agent or the like according to a conventional method, if necessary, to prevent deterioration of characteristics.

[0371] As described above, the charge transport varnish of the present invention is preferably used for forming functional layers provided between the anode and the light-emitting layer, such as the hole injection layer, the hole transport layer, and the hole injection and transport layer of an organic EL element. In addition, it can also be used to form charge transport thin films in electronic elements such as organic photoelectric conversion elements, organic thin-film solar cells, organic perovskite photoelectric conversion elements, organic integrated circuits, organic electric field effect transistors, organic thin-film transistors, organic light-emitting transistors, organic optical detectors, organic photosensors, organic electroluminescent elements, light-emitting electrochemical cells, quantum dot light-emitting diodes, quantum lasers, organic laser diodes, and organic plasmon light-emitting elements.

[0372] Example

[0373] The present invention will be described in more detail below with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples.

[0374] (1) MALDI-TOF-MS: Bruker, autoflex III smartbeam

[0375] (2) 1 H-NMR: JNM-ECP300 FT NMR SYSTEM manufactured by JEOL Ltd.

[0376] (3) Substrate cleaning: Substrate cleaning equipment manufactured by Choshu Industry Co., Ltd. (reduced pressure plasma method)

[0377] (4) Varnish coating: Spin coater MS-A100 manufactured by Mikasa Co., Ltd.

[0378] (5) Film thickness measurement: SURFCORDER ET-4000, manufactured by Kosaka Laboratory Co., Ltd.

[0379] (6) Component production: Choshu Industry Co., Ltd. multifunctional vapor deposition system C-E2L1G1-N

[0380] (7) Measurement of current density of the device: Multi-channel IVL measuring device manufactured by EHC Co., Ltd.

[0381] (8) Determination of refractive index (n): Multi-incident angle spectroscopic ellipsometer VASE manufactured by JA Woollam Japan

[0382] [1]Manufacture of aniline derivatives

[0383] [Synthesis Example 1] Preparation of Aniline Derivative A

[0384] [Chemistry 44]

[0385]

[0386] (1) Synthesis of N,N-bis(3-nitrophenyl)-9-phenyl-9H-carbazole-3-amine

[0387] 1.00 g of bis(3-nitrophenyl)amine, 1.37 g of 3-bromo-9-phenyl-9H-carbazole, 0.0678 g of bis(dibenzylideneacetone)palladium, 0.0983 g of di-tert-butyl(2',4',6'-triisopropyl-[1,1'-diphenyl]-2-yl)phosphine (tBuXPhos), 1.61 g of potassium carbonate, and 10 mL of toluene were placed in a reaction vessel. After nitrogen substitution, the reaction mixture was stirred at 100°C for 24.5 hours. After completion of the reaction, toluene and saturated brine were added to separate the layers. The organic layer was filtered through silica gel, and the filtrate was concentrated. Chloroform and hexane were added to the concentrated residue to prepare a solution, which was then purified by column chromatography (the eluent was a mixed solvent of chloroform / hexane) to obtain 1.02 g (yield: 53%) of the target N,N-bis(3-nitrophenyl)-9-phenyl-9H-carbazole-3-amine.

[0388] MALDI-TOF-MS m / z measured value: 499.86 ([M] + Calculated value: 500.15)

[0389] (2) Synthesis of N1-(3-aminophenyl)-N1-(9-phenyl-9H-carbazol-3-yl)benzene-1,3-diamine

[0390] 0.603 g of N,N-bis(3-nitrophenyl)-9-phenyl-9H-carbazol-3-amine, 0.0582 g of 5% palladium / carbon (manufactured by NE Chemkit, AER type, 50% water content), and 9 mL of tetrahydrofuran were placed in a reaction vessel. The reaction vessel was purged with hydrogen and stirred at 50°C for 24 hours. After cooling to room temperature, the reaction solution was filtered through Celite (Celite 545 was used). The filtrate was dried to obtain 0.486 g of the target N1-(3-aminophenyl)-N1-(9-phenyl-9H-carbazol-3-yl)benzene-1,3-diamine (yield: 92%).

[0391] 1 H-NMR (500MHz, CDCl3) δ [ppm]: 8.00 (d, J=8.0Hz, 1H), 7.92 (m, 1H), 7.56-7.60 (m, 4H), 7.45 (m, 1H), 7.37-7.38 (m, 2H) , 7.32 (d, J = 8.5Hz, 1H), 7.20-7.23 (m, 2H), 6.98-7.02 (m, 2H), 6.52 (d, J = 8.0Hz, 2H), 6.45 (m, 2H), 6.29-6.31 (m, 2H).

[0392] (3) Synthesis of aniline derivative A

[0393] 0.451 g of the above-obtained N1-(3-aminophenyl)-N1-(9-phenyl-9H-carbazole-3-yl)benzene-1,3-diamine, 1.45 g of 3-bromo-9-phenyl-9H-carbazole, 0.0234 g of palladium acetate, and 0.539 g of sodium tert-butoxide were placed in a reaction vessel. After nitrogen substitution, 10 mL of toluene and 0.84 mL of a toluene solution of phenyldi-tert-butylphosphine (concentration: 54.0 g / L) prepared in advance were added, and the mixture was stirred at 90°C for 1.5 hours. After cooling to room temperature, toluene and saturated brine were added to separate the liquids. The organic layer was filtered through silica gel, and the filtrate was concentrated. The resulting concentrate was added dropwise to a mixed solvent of methanol / ethyl acetate and stirred at room temperature. The slurry solution was filtered, and the filtrate was dried to obtain 0.855 g of the target aniline derivative A (yield: 59%).

[0394] MALDI-TOF-MS m / z measured value: 2620.94 ([M] + Calculated value: 2620.08)

[0395] [2] Preparation of charge transport varnish

[0396] [Example 1-1]

[0397] To a mixture of 0.221 g of the aniline derivative A obtained in Synthesis Example 1 and 0.196 g of an arylsulfonate B represented by the following formula, synthesized according to the method described in International Publication No. 2017 / 217455, 3.0 g of 3-phenoxytoluene and 7 g of butyl benzoate were added, and the mixture was stirred at room temperature to dissolve. The resulting solution was filtered through a syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0398] [Chemistry 45]

[0399]

[0400] [Comparative Example 1-1]

[0401] A charge-transporting varnish was obtained in the same manner as in Example 1-1 except that the aniline derivative A was replaced with the aniline derivative C represented by the following formula and synthesized according to the method described in International Publication No. 2015 / 050253.

[0402] [Chemistry 46]

[0403]

[0404] [3] Thin film production and film property evaluation

[0405] [Example 2-1 and Comparative Example 2-1]

[0406] The varnishes prepared in Example 1-1 and Comparative Example 1-1 were each applied to a quartz substrate using a spin coater and then dried at 120°C for 1 minute in an atmospheric firing atmosphere. The dried coated quartz substrates were then fired at 200°C for 15 minutes or at 230°C for 15 minutes in an atmospheric firing atmosphere to form a uniform 50 nm thin film on the quartz substrate.

[0407] The refractive index n (average refractive index at a wavelength of 400 nm to 800 nm) of the obtained film was measured. The results are shown in Table 1.

[0408] [Table 1]

[0409]

[0410] As shown in Table 1, it is found that the refractive index of the thin film obtained from the varnish of the present invention is higher than that of the case where an aniline derivative having a similar structure is used.

[0411] [4] Fabrication and characteristic evaluation of single-layer components

[0412] [Example 3-1]

[0413] The varnish prepared in Example 1-1 was applied to an ITO substrate using a spin coater, dried at 120°C for 1 minute, and then fired at 200°C for 15 minutes or at 230°C for 15 minutes to produce a charge transport thin film. -5 A single-layer device was obtained by forming an aluminum thin film on a 25 mm × 25 mm × 0.7 t glass substrate with a 150 nm thick indium tin oxide (ITO) patterned on the surface. Prior to use, impurities on the surface were removed using an O2 plasma cleaner (150 W, 30 seconds). Vapor deposition was performed at a rate of 0.2 nm / second. The thickness of the aluminum thin film was set to 80 nm.

[0414] The current density of the single-layer device produced above was measured at a driving voltage of 3 V. The results are shown in Table 2.

[0415] [Table 2]

[0416]

[0417] As shown in Table 2, the charge-transporting thin film of the present invention exhibits excellent charge-transporting properties not only when fired at high temperatures but also when fired at low temperatures.

[0418] [5] Fabrication and characteristic evaluation of single-hole devices

[0419] [Example 4-1]

[0420] Using the varnish prepared in Example 1-1 and the same ITO substrate as used in Example 3-1, a charge transporting thin film was produced on the ITO substrate in the same manner as in Example 3-1.

[0421] Next, the ITO substrate on which the thin film was formed was subjected to a deposition process using a vapor deposition apparatus (vacuum degree 1.0×10 -5 A 30 nm thick film of α-NPD (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine) was deposited at 0.2 nm / s. An 80 nm thick aluminum thin film was stacked thereon in the same manner as in Example 3-1 to produce a single hole device.

[0422] [Comparative Example 4-1]

[0423] A single-hole device was produced in the same manner as in Example 4-1, except that the varnish prepared in Comparative Example 1-1 was used instead of the varnish prepared in Example 1-1.

[0424] For each of the hole-only devices produced above, the current density at a driving voltage of 3 V was measured. The results are shown in Table 3.

[0425] [Table 3]

[0426]

[0427] As shown in Table 3, for the charge transport film obtained from the varnish of the comparative example containing an aniline derivative of a similar structure, a decrease in current density was observed when calcined at 200°C, that is, a significant deterioration in hole injection properties into α-NPD, which is often used as a hole transport layer, was observed. However, for the charge transport film of the example, no such deterioration was observed when calcined at 200°C, and the film showed excellent hole injection properties.

Claims

1. A charge transport varnish, characterized in that Containing: an aniline derivative represented by the following formula (1), and an organic solvent, [Chemistry 1] Where Ph 1 Each independently represents a group represented by formula (P1) or formula (P2), at least one of which is a group represented by formula (P1), [Chemistry 2] Where R 1 ~R 4 each independently represents a hydrogen atom, a cyano group, or 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 which may be substituted by a cyano group, Ar 0 each independently represents a group represented by any one of formulae (B1) to (B12) and (B14), [Chemistry 3] Where R 5 ~R 25 、R 28 ~R 49 、R 51 ~R 159 and R 167 ~R 178 Each independently represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, or a diphenylamino group which may be substituted with a halogen atom, a nitro group, or a cyano group, 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, and R 26 and R 27 Each independently represents a hydrogen atom, which may be replaced by Z 1 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 1 Substituted alkenyl with 2 to 20 carbon atoms, which may be Z 1 The substituted alkynyl group having 2 to 20 carbon atoms may be Z 2 The substituted aryl group having 6 to 20 carbon atoms may be Z 2 Substituted heteroaryl having 2 to 20 carbon atoms, R 50 Represents hydrogen atoms, which can be Z 1 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 1 Substituted alkenyl with 2 to 20 carbon atoms, which may be Z 1 The substituted alkynyl group having 2 to 20 carbon atoms may be Z 2 The substituted aryl group having 6 to 20 carbon atoms may be Z 2 Substituted heteroaryl having 2 to 20 carbon atoms, Z 1 Represents a halogen atom, nitro, cyano, diphenylamino, which can be Z 3 The substituted aryl group having 6 to 20 carbon atoms may be Z 3 Substituted heteroaryl having 2 to 20 carbon atoms, Z 2 Represents a halogen atom, nitro, cyano, diphenylamino, which can be Z 3 Alkyl groups with 1 to 20 carbon atoms, which may be substituted by Z 3 The substituted alkenyl group having 2 to 20 carbon atoms may be Z 3 Substituted alkynyl having 2 to 20 carbon atoms, Z 3 represents a halogen atom, a nitro group, a cyano group or a diphenylamino group, Ar 4 each independently represents an aryl group having 6 to 20 carbon atoms which may be substituted with a di(aryl group having 6 to 20 carbon atoms)amino group, k represents an integer greater than or equal to 1.

2. The charge transport varnish according to claim 1, wherein The aniline derivative represented by the formula (1) is represented by any one of the formulas (1-1) to (1-4): [Chemistry 4] Ar 1 ~Ar 3 Different from each other, it is a group represented by any one of the formulae (B1) to (B12) and (B14), in each formula, Ar 1 All represent the same group, Ar 2 All represent the same group, Ar 3 All represent the same group.

3. The charge transport varnish according to claim 1, wherein The number (n) of groups represented by the formula (P1) m ) and the number of groups represented by the formula (P2) (n p ) satisfies 0.5≤n m / (n m +n p ). 4 . The charge-transporting varnish according to claim 1 , comprising a dopant substance.

5. The charge transporting varnish according to claim 4, wherein The dopant substance is an aryl sulfonate compound. 6 . A charge-transporting thin film produced using the charge-transporting varnish according to claim 1 .

7. An electronic component comprising the charge transport thin film according to claim 6.

8. An organic electroluminescent element comprising the charge transport thin film according to claim 6.

9. The organic electroluminescent element according to claim 8, wherein The charge transport thin film is a hole injection layer or a hole transport layer.

Images