Arylamine compound and use thereof

Abstract

Provided is an arylamine compound represented by formula (1a), for example, as an arylamine compound capable of providing a thin film having good solubility in an organic solvent and good charge transport properties, and capable of realizing an organic EL element having good characteristics when the thin film is applied to a hole injection layer or the like.

Description

Arylamine compounds and their uses

[0001] The present invention relates to an arylamine compound and its use.

[0002] Organic electroluminescence (hereinafter referred to as organic EL) elements are expected to be put to practical use in fields such as displays and lighting, and various developments have been made on materials and element structures with the aim of achieving low-voltage operation, high brightness, long life, etc. Organic EL elements use multiple functional thin films, one of which is the hole injection layer, which is responsible for the exchange of charges between the anode and the hole transport layer or the light-emitting layer, and plays an important role in achieving low-voltage operation and high brightness of organic EL elements.

[0003] Methods for fabricating hole injection layers can be broadly divided into dry processes, such as vapor deposition, and wet processes, such as inkjet printing and spin coating. Compared to these processes, wet processes are more efficient at producing thin films with high flatness over large areas. Therefore, as organic EL displays continue to grow in size, there is a demand for hole injection layers that can be formed by wet processes.

[0004] In view of these circumstances, the present inventors have developed charge transport materials that are applicable to various wet processes and that, when applied to the hole injection layer of an organic EL device, give thin films that can realize excellent EL device characteristics, as well as compounds that have good solubility in organic solvents used therefor (see Patent Documents 1 to 3).

[0005] Furthermore, in recent years, with the development of display technology, quantum dot electroluminescence (hereinafter referred to as quantum dot EL) devices, which use quantum dot materials as light-emitting layers, have emerged and are showing promise for a wide range of applications. These quantum dot EL devices can be manufactured at low cost using wet processes, and are attracting much attention in fields such as display technology and lighting due to their characteristics, such as controllability of emission wavelength, high color purity, high luminous efficiency, and flexibility.

[0006] However, from the viewpoint of further improving the performance of organic EL devices and quantum dot EL devices, further investigations are being conducted on materials for forming charge transport thin films such as hole injection layers.

[0007] International Publication No. WO 2008 / 129947 International Publication No. WO 2015 / 050253 International Publication No. WO 2017 / 217457

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an arylamine compound that has good solubility in organic solvents and can give a thin film with good charge transport properties, and that can realize an organic EL device having good characteristics when the thin film is applied to a hole injection layer or the like.

[0009] As a result of extensive research into achieving the above object, the present inventors have found that an arylamine compound having a specific chain molecular structure has good solubility in organic solvents, that a varnish obtained by dissolving this compound in an organic solvent gives a thin film with excellent charge transport properties, and that when this thin film is used as a hole injection layer or the like, an organic EL device with good characteristics can be obtained, and have completed the present invention.

[0010] That is, the present invention provides the following arylamine compounds and uses thereof: 1. An arylamine compound represented by the following formula (1): [In the formula, X 1 each independently represents a single bond or a group represented by any one of the following formulae (a1-1) to (a1-2), (a2-1) to (a2-4), (a3-1) to (a3-4), and (a4) to (a9); X 2 each independently represents a group represented by any one of the following formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a3-1) to (a3-4), and (a4) to (a9): (In the formula, R 1 Each independently represents an alkyl group having 1 to 20 carbon atoms. A dashed line represents a bond. 1 each independently represents a group represented by the following formula (b1) or (b2): wherein Y is NZ 3 , O or S; Z 1 , Z2 and Z 3 each independently represents a group represented by any one of the following formulae (c1) to (c4): A dashed line represents a bond. (In the formula, the dashed line represents a bond.) n represents an integer of 0 to 5. However, when n is 0, X 1 does not become a single bond.] 2. The above X 1 are each independently a single bond or a group represented by any one of the above formulae (a1-1) to (a1-2), (a2-1) to (a2-4), (a4) and (a7), and the above X 2 are each independently a group represented by any one of the above formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a4) and (a7). 1 is a group represented by the above formula (b1). 1 are each independently an alkyl group having 1 to 4 carbon atoms. 3 6. The arylamine compound according to any one of 1 to 4, wherein Z 1 , Z 2 and Z 3 is a group represented by formula (c1). 7. An arylamine compound of any one of 1 to 5. 8. A charge transporting material comprising the arylamine compound of any one of 1 to 6. 9. A charge transporting varnish comprising the arylamine compound of any one of 1 to 6 and an organic solvent. 10. A charge transporting varnish of 8 further comprising a dopant substance. 11. An electronic device comprising the charge transporting thin film of 10. 12. An electronic device of 11, in which the charge transporting thin film is a hole injection layer or a hole transport layer. 13. An electronic device of 12, in which the electronic device is an organic EL device or a quantum dot EL device.

[0011] The arylamine compound of the present invention has good solubility in organic solvents, and by using a charge-transporting varnish containing this arylamine compound, a charge-transporting thin film with excellent charge transport properties can be obtained. This charge-transporting thin film can be suitably used as a thin film for electronic devices such as organic EL devices and quantum dot EL devices, particularly as a thin film for electronic devices in which a thin film is laminated on top by a wet process. By applying the charge-transporting thin film of the present invention to the hole-injection layer of an organic EL device or a quantum dot EL device, a device with excellent properties can be produced.

[0012] The present invention will be described in more detail below. The arylamine compound according to the present invention is characterized by being represented by the following formula (1).

[0013]

[0014] In formula (1), X 1 each independently represents a single bond or a group represented by any one of the following formulae (a1-1) to (a1-2), (a2-1) to (a2-4), (a3-1) to (a3-4), and (a4) to (a9); X 2 each independently represents a group represented by any one of the following formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a3-1) to (a3-4), and (a4) to (a9).

[0015] (The dashed lines represent bonds.)

[0016] In formulas (a7) to (a9), R 1 each independently represents an alkyl group having 1 to 20 carbon atoms.

[0017] Ar 1 each independently represents a group represented by the following formula (b1) or (b2):

[0018] (The dashed lines represent bonds.)

[0019] In the formulas (b1) and (b2), Y is NZ 3 , O or S; Z 1 , Z 2 and Z 3each independently represents a group represented by any one of the following formulas (c1) to (c4):

[0020] (In the formula, the dashed lines represent bonds.)

[0021] n represents an integer of 0 to 5. However, when n is 0, X 1 does not become a single bond.

[0022] The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; 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 groups. In the present invention, from the viewpoint of charge transport properties, alkyl groups having 1 to 4 carbon atoms are preferred, and methyl groups are more preferred.

[0023] Above X 1 From the viewpoint of charge transportability, a single bond or a group represented by any one of the above formulae (a1-1) to (a1-2), (a2-1) to (a2-4), (a4) and (a7) is preferred.

[0024] Above X 2 From the viewpoint of charge transportability, the group is preferably a group represented by any one of the above formulae (a1-1) to (a1-2), (a2-1) to (a2-4), (a4) and (a7).

[0025] In addition, the above X 1 and X 2 is preferably not all phenylene groups (i.e., not all groups represented by formula (a1-1) and (a1-2)) in terms of ensuring transparency when formed into a film or charge transport properties.

[0026] The above Ar 1is preferably a group represented by the above formula (b1) from the viewpoint of charge transport properties.

[0027] The above Y is NZ from the viewpoint of charge transportability. 3 is preferred, and the above Z 1 , Z 2 and Z 3 is preferably a group represented by the above formula (c1).

[0028] As the groups represented by the above formulae (a4) to (a9), from the viewpoint of charge transport properties, groups represented by the following formulae (a4-1) to (a9-3) are preferred, but are not limited thereto.

[0029] (In the formula, R 1 has the same meaning as above.)

[0030] A preferred embodiment of the arylamine compound represented by the above formula (1) includes, but is not limited to, a compound represented by the following formula (1-1):

[0031] (In the formula, X 2 and n have the same meaning as above.)

[0032] Specific examples of the compound represented by formula (1) include, but are not limited to, compounds represented by the following formulas (1a) to (1d).

[0033]

[0034] The arylamine compound represented by formula (1) of the present invention can be produced by reacting a predetermined aryldiamine compound with a predetermined aryl halide compound in the presence of a catalyst. As a method for producing the arylamine compound, known methods described in WO 2020 / 241730 and the like can be used as reference.

[0035] The arylamine compound of the present invention described above can be suitably used as a charge transport material. In this case, it can be used as a charge transport varnish containing the arylamine compound of the present invention and an organic solvent. This charge transport varnish may contain a dopant substance for the purpose of improving the charge transport ability, etc., depending on the application of the resulting thin film. Furthermore, the arylamine compound of the present invention can be used in combination with other conventionally known charge transport materials such as aniline derivatives and thiophene derivatives, but it is preferable to use the arylamine compound of the present invention alone as the charge transport material. In the present invention, charge transportability is synonymous with conductivity. The charge transport varnish may itself have charge transportability, or the solid film obtained therefrom may have charge transportability.

[0036] 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. Furthermore, the inorganic and organic dopant substances may be used alone or in combination of two or more. Furthermore, the dopant substance may be a substance whose function as a dopant substance is first exhibited or improved by, for example, a part of its molecule being removed by an external stimulus, such as heating during baking, during the process of obtaining a charge-transporting thin film, which is a solid film, from the varnish, for example, an arylsulfonic acid ester compound protected by a group that easily removes the sulfonic acid group.

[0037] In particular, heteropolyacids are preferred as inorganic dopant substances in the present invention. Heteropolyacids are polyacids that have a structure in which a heteroatom is located at the center of the molecule, typically represented by a Keggin-type chemical structure represented by formula (H1) or a Dawson-type chemical structure represented by formula (H2), and are formed by condensing an isopolyacid, which is an oxyacid of vanadium (V), molybdenum (Mo), tungsten (W), or the like, with an oxyacid of a different element. Examples of such oxyacids of different elements include oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

[0038]

[0039] Specific examples of heteropolyacids include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, and phosphotungstomolybdic acid, which may be used alone or in combination of two or more. These heteropolyacids are commercially available or can be synthesized by known methods. In particular, when one type of heteropolyacid is used, that heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, with phosphotungstic acid being the most preferable. In addition, when two or more types of heteropolyacids are used, one of the two or more types of heteropolyacids is preferably phosphotungstic acid or phosphomolybdic acid, with phosphotungstic acid being more preferable. Heteropolyacids can be used in the present invention regardless of whether they contain a large number of elements or a small number of elements in a structure represented by the general formula in quantitative analysis such as elemental analysis, as long as they are commercially available or appropriately synthesized according to a known synthesis method. That is, for example, phosphotungstic acid is generally represented by the chemical formula H(PW 12 O 40 )·nH2O, and phosphomolybdic acid has the chemical formula H3(PMo 12 O 40 )·nHO, but whether the number of P (phosphorus), O (oxygen), W (tungsten), or Mo (molybdenum) in this formula is high or low in quantitative analysis, it can be used in the present invention as long as it is obtained as a commercially available product or appropriately synthesized according to a known synthesis method. In this case, the mass of the heteropolyacid specified in the present invention does not refer to the mass of pure phosphotungstic acid (phosphotungstic acid content) in a synthesized or commercially available product, but rather refers to the total mass, including water of hydration and other impurities, in a form available as a commercially available product or in a form that can be isolated by a known synthesis method.

[0040] The amount of heteropolyacid used can be about 0.001 to 50.0 parts by mass per 1 part of the charge transporting substance, preferably about 0.01 to 20.0 parts, and more preferably about 0.1 to 10.0 parts.

[0041] On the other hand, as organic dopant substances, tetracyanoquinodimethane derivatives and benzoquinone derivatives can be particularly used. Specific examples of tetracyanoquinodimethane derivatives include 7,7,8,8-tetracyanoquinodimethane (TCNQ) and halotetracyanoquinodimethane represented by formula (H3). Specific examples of benzoquinone derivatives include tetrafluoro-1,4-benzoquinone (F4BQ), tetrachloro-1,4-benzoquinone (chloranil), tetrabromo-1,4-benzoquinone, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ).

[0042]

[0043] In the formula, R 500 ~R 503 are each independently a hydrogen atom or a halogen atom, at least one of which is a halogen atom, preferably at least two of which are halogen atoms, more preferably at least three of which are halogen atoms, and most preferably all of which are halogen atoms. Examples of halogen atoms include the same as those mentioned above, but a fluorine atom or a chlorine atom is preferred, and a fluorine atom is more preferred.

[0044] Specific examples of such halotetracyanoquinodimethanes 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).

[0045] 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 charge transporting substance.

[0046] Furthermore, as the organic dopant substance, electrically neutral onium borate salts composed of a monovalent or divalent anion represented by the following formula (e1) and a counter cation represented by any of the formulae (f1) to (f5) can also be used.

[0047] (In the formula, each Ar independently represents an aryl group having 6 to 20 carbon atoms which may have a substituent, or a heteroaryl group having 2 to 20 carbon atoms which may have a substituent; L represents an alkylene group having 1 to 20 carbon atoms, —NH—, an oxygen atom, a sulfur atom, or —CN + - represents.)

[0048]

[0049] In formula (e1), the alkylene group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methylene, methylmethylene, dimethylmethylene, ethylene, trimethylene, propylene, tetramethylene, pentamethylene, hexamethylene, etc. Examples of the aryl group and heteroaryl group include the same as those described above.

[0050] Suitable examples of the anion of the above formula (e1) include, but are not limited to, those represented by formula (e2).

[0051]

[0052] The amount of the onium borate salt used, in terms of mole ratio relative to the charge transporting substance, can be about 0.1 to 10. The onium borate salt can be synthesized with reference to known methods described, for example, in JP-A-2005-314682.

[0053] Furthermore, as organic dopant substances, arylsulfonic acid compounds, arylsulfonic acid ester compounds, and fluorinated arylsulfonic acid polymer compounds can also be suitably used.

[0054] Specific examples of the arylsulfonic acid compound include benzenesulfonic acid, tosylic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, 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, and 7-hexyl-1-naphthalenesulfonic acid. Examples of suitable arylsulfonic acids include talenesulfonic acid, 6-hexyl-2-naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-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 WO 2005 / 000832, arylsulfonic acid compounds described in WO 2006 / 025342, and arylsulfonic acid compounds described in WO 2009 / 096352.

[0055] Preferred examples of the arylsulfonic acid compound include arylsulfonic acid compounds represented by formula (H4) or (H5).

[0056]

[0057] A 1 represents O or S, with O being preferred. 2 represents a naphthalene ring or an anthracene ring, with a naphthalene ring being preferred. 3 represents a divalent to tetravalent perfluorobiphenyl group, and p represents A 1 and A 3 and is an integer satisfying 2≦p≦4, but A 3 is a perfluorobiphenyldiyl group, preferably a perfluorobiphenyl-4,4'-diyl group, and p is preferably 2. 2 represents the number of sulfonic acid groups bonded to the hydroxyl group, and is an integer satisfying the relationship 1≦q≦4, with 2 being optimal.

[0058] 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 halogenated alkyl group having 1 to 20 carbon atoms, or a halogenated alkenyl group having 2 to 20 carbon atoms; 4 ~A 8 At least three of the groups are halogen atoms.

[0059] Examples of halogenated alkyl groups 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 groups.

[0060] Examples of halogenated alkenyl groups having 2 to 20 carbon atoms include perfluorovinyl, perfluoropropenyl (perfluoroallyl), perfluorobutenyl, etc. Other examples of halogen atoms and alkyl groups having 1 to 20 carbon atoms include those similar to those mentioned above, but the halogen atom is preferably a fluorine atom.

[0061] Among these, A 4 ~A 8 is a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, and A 4 ~A 8 At least three of A are preferably fluorine atoms, and are selected from the group consisting of a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, and a fluorinated alkenyl group having 2 to 5 carbon atoms, and 4 ~A 8At least three of A are preferably fluorine atoms, and A is preferably a hydrogen atom, a fluorine atom, a cyano group, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkenyl group having 1 to 5 carbon atoms. 4 , A 5 and A 8 It is more preferable that each of the hydrogen atoms of the alkyl group and the perfluoroalkenyl group is a group in which all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms.

[0062] 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.

[0063] 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, taking into consideration the solubility in organic solvents when used together with the arylamine compound of the present invention.

[0064] Specific examples of suitable aryl sulfonic acid compounds are listed below, but the present invention is not limited to these.

[0065]

[0066]

[0067]

[0068] The amount of the arylsulfonic acid compound used, in terms of a molar ratio of substance, is preferably about 0.01 to 20.0, and more preferably about 0.4 to 5.0, relative to the charge-transporting substance of 1. Commercially available arylsulfonic acid compounds may be used, but they can also be synthesized by known methods described in WO 2006 / 025342, WO 2009 / 096352, WO 2015 / 111654, WO 2015 / 053320, WO 2015 / 115515, and the like.

[0069] On the other hand, examples of the aryl sulfonate ester compound include the aryl sulfonate ester compounds disclosed in WO 2017 / 217455, the aryl sulfonate ester compounds disclosed in WO 2017 / 217457, and the aryl sulfonate ester compounds described in Japanese Patent Application No. 2017-243631 (WO 2019 / 124412), and specifically, those represented by any of the following formulae (H6) to (H8) are preferred.

[0070] (In the formula, j is an integer satisfying 1≦j≦4, preferably 2. k is an integer satisfying 1≦k≦4, preferably 2.)

[0071] In formula (H6), A 11 is a j-valent group derived from perfluorobiphenyl. 12 is —O— or —S—, with —O— being preferred. 13 is a (k+1)-valent group derived from naphthalene or anthracene, with a group derived from naphthalene being preferred. s1 ~R s4 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R s5 is an optionally substituted monovalent hydrocarbon group having 2 to 20 carbon atoms.

[0072] Specific examples of linear or branched alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-hexyl groups, with alkyl groups having 1 to 3 carbon atoms being preferred. The monovalent hydrocarbon group having 2 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include alkyl groups such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups; and aryl groups such as phenyl, naphthyl, and phenanthryl groups.

[0073] In particular, R s1 ~R s4 Among them, R s1 or R s3 is a linear alkyl group having 1 to 3 carbon atoms, and the rest are hydrogen atoms, or Rs1 is a linear alkyl group having 1 to 3 carbon atoms, and R s2 ~R s4 is preferably a hydrogen atom. In this case, the linear alkyl group having 1 to 3 carbon atoms is preferably a methyl group. s5 As the alkyl group, a linear alkyl group having 2 to 4 carbon atoms or a phenyl group is preferred.

[0074] In formula (H7), A 14 is an optionally substituted j-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, and this hydrocarbon group is a group obtained by removing j hydrogen atoms from a hydrocarbon compound having 6 to 20 carbon atoms and containing one or more aromatic rings. Examples of such hydrocarbon compounds include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, and phenanthrene. Some or all of the hydrogen atoms in the hydrocarbon group may be further substituted with a substituent, and examples of such a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, nitro, cyano, hydroxy, amino, silanol, thiol, carboxy, sulfonate ester, phosphoric acid, phosphate ester, ester, thioester, amide, organooxy, organoamino, organosilyl, organothio, acyl, sulfo, and a monovalent hydrocarbon group. Among these, A 14 As the alkyl group, groups derived from benzene, biphenyl, etc. are preferred.

[0075] Also, A 15 is —O— or —S—, with —O— being preferred. 16 is a (k+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is a group obtained by removing (k+1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, A 16 As the alkyl group, a group derived from naphthalene or anthracene is preferred, and a group derived from naphthalene is more preferred.

[0076] R s6 and R s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group, and R s8 is a linear or branched monovalent aliphatic hydrocarbon group, provided that R 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 in is not particularly limited, but is preferably 20 or less, and more preferably 10 or less. Specific examples of the linear or branched monovalent aliphatic hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-hexyl, n-octyl, 2-ethylhexyl, and decyl groups; 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 groups. Among these, R s6 is preferably a hydrogen atom, and R s7 and R s8 are each independently preferably an alkyl group having 1 to 6 carbon atoms.

[0077] In formula (H8), R s9 ~R s13 are each independently a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups.

[0078] The halogenated alkyl group having 1 to 10 carbon atoms is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms have been substituted with halogen atoms, and 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 groups.

[0079] The halogenated alkenyl group having 2 to 10 carbon atoms is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of an alkenyl group having 2 to 10 carbon atoms have been substituted with halogen atoms, and specific examples thereof include perfluorovinyl, perfluoro-1-propenyl, perfluoro-2-propenyl, perfluoro-1-butenyl, perfluoro-2-butenyl, and perfluoro-3-butenyl groups.

[0080] Among these, R s9 R is preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, more preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 4 carbon atoms, or a halogenated alkenyl group having 2 to 4 carbon atoms, and even more preferably a nitro group, a cyano group, a trifluoromethyl group, or a perfluoropropenyl group. s10 ~R s13 As the atom, a halogen atom is preferable, and a fluorine atom is more preferable.

[0081] A 17 is —O—, —S— or —NH—, with —O— being preferred. 18is a (k+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is a group obtained by removing (k+1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, A 18 As the alkyl group, a group derived from naphthalene or anthracene is preferred, and a group derived from naphthalene is more preferred.

[0082] R s14 ~R s17 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. Specific examples of the monovalent aliphatic hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl groups; 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 groups. Of these, 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 even more preferred.

[0083] R s18 represents a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or OR s19 It is. s19 R is a monovalent hydrocarbon group having 2 to 20 carbon atoms which may be substituted. s18 Examples of the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms include the same as those described above. s18 is a monovalent aliphatic hydrocarbon group, R s18 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and even more preferably an alkyl group having 1 to 8 carbon atoms. s19Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms include the above-mentioned monovalent aliphatic hydrocarbon groups other than the methyl group, as well as aryl groups such as phenyl, naphthyl, and phenanthryl groups. s19 is preferably a linear alkyl group having 2 to 4 carbon atoms or a phenyl group. 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.

[0084] Specific examples of suitable aryl sulfonate compounds include, but are not limited to, those shown below.

[0085]

[0086]

[0087]

[0088] The amount of the arylsulfonate ester compound used, in terms of a molar ratio of substance, relative to 1 part of the charge-transporting substance, is preferably about 0.01 to 20 parts, and more preferably about 0.05 to 10 parts. Although commercially available arylsulfonate ester compounds may be used, they can also be synthesized by known methods described in WO 2017 / 217455, WO 2017 / 217457, WO 2019 / 124412, and the like.

[0089] The fluorinated arylsulfonic acid polymer compound is characterized by containing a repeating unit represented by the following formula (F1):

[0090]

[0091] In formula (F1), Ar F represents a fluorinated arylene group. FThe fluorinated arylene group of the formula (I) is not particularly limited as long as at least one hydrogen atom on the arylene group is substituted with a fluorine atom, but it is preferable that at least one of the remaining hydrogen atoms is substituted with an electron-withdrawing group other than a sulfo group. Examples of the electron-withdrawing group include halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; nitro group; cyano group; acyl group; carboxy group; carboxylic acid ester group; and acyl groups such as formyl group and acetyl group. In particular, Ar F The fluorinated arylene group is preferably an arylene group substituted with two or more fluorine atoms, and more preferably a perfluoroarylene group.

[0092] Ar F There is no particular limitation on the number of carbon atoms in the arylene group constituting Ar, but the number of carbon atoms is preferably 6 to 20, and more preferably 6 to 16. Specific examples thereof include 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, 1,5-naphthylene, 1,7-naphthylene, 1,8-naphthylene, 2,6-naphthylene, 2,7-naphthylene, 4,4'-biphenylylene, and anthracenyl groups, with a phenylene group being preferred and a 1,4-phenylene group being more preferred. Therefore, Ar F As the alkyl group, a tetrafluorophenylene group is preferred, and a 2,3,5,6-tetrafluoro-1,4-phenylene group is more preferred.

[0093] X represents O, S, NH, CONH or NHCO, with O and S being preferred, and O being more preferred.

[0094] A preferred fluorinated arylsulfonic acid polymer compound of the present invention is one represented by the following formula (F1-1):

[0095] (In the formula, n1 represents an integer of 1 to 4.)

[0096] More preferred fluorinated arylsulfonic acid polymer compounds include those represented by the following formula (F1-2).

[0097] (In the formula, n1 represents an integer of 1 to 4.)

[0098] A more suitable fluorinated arylsulfonic acid polymer compound is one represented by the following formula (F1-3).

[0099]

[0100] Ar S has at least one SO3R on the ring w represents an aryl group having a group, and R w represents a hydrogen atom or an alkali metal atom such as Li, Na, or K, and is preferably a hydrogen atom. S There is no particular limitation on the number of carbon atoms in the aryl group constituting Ar, but it is preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and even more preferably 6 to 12 carbon atoms. Specific examples thereof include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl groups, with naphthyl groups being preferred, and 1-naphthyl groups being more preferred. S The number of SO3R groups contained in Ar may be one or more, but is preferably 2 to 4, and more preferably 2. S As the compound represented by the following formula (Ar S -1) to (Ar S -6).

[0101] (In the formula, R w represents the same meaning as above. n2 represents an integer of 2 to 4.

[0102] (In the formula, R w has the same meaning as above.)

[0103] (In the formula, R w has the same meaning as above.)

[0104] (In the formula, R w has the same meaning as above.)

[0105] The fluorinated arylsulfonic acid polymer compound of the present invention may be a polymer containing only a repeating unit represented by the above formula (1). However, from the viewpoint of increasing solubility in organic solvents, a polymer further containing a repeating unit represented by the following formula (F2) is preferred.

[0106]

[0107] In formula (F2), R' represents a monovalent organic group. Examples of this monovalent organic group include a monovalent hydrocarbon group, a heteroaryl group, and a -COOR" group (wherein R" represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms). There are no particular restrictions on the number of carbon atoms in the monovalent hydrocarbon group, but a carbon number of 1 to 20 is preferred, a carbon number of 6 to 20 is more preferred, and a carbon number of 6 to 10 is even more preferred. Specific examples thereof include alkyl groups 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, and n-decyl; and aryl groups such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl.

[0108] Specific examples of heteroaryl groups include heteroaryl groups having 2 to 20 carbon atoms, such as 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, and 4-pyridyl groups.

[0109] Examples of the alkyl group having 1 to 10 carbon atoms for R″ include the same groups as those exemplified above, and among these, alkyl groups having 1 to 5 carbon atoms are preferred.

[0110] In addition, the monovalent hydrocarbon group, heteroaryl group, and alkyl group having 1 to 10 carbon atoms represented by R" may have some or all of their hydrogen atoms substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, a carboxy group, a sulfo group, and a hydroxyl group. Examples of the halogen atom include the same atoms as those exemplified above.

[0111] Among these, in consideration of improving the device characteristics and life characteristics of an organic EL device obtained by using the fluorinated arylsulfonic acid polymer compound of the present invention as a dopant substance, R' is preferably an aryl group substituted with a halogen atom, more preferably a fluorinated aryl group, and even more preferably a perfluoroaryl group. In particular, R' is preferably a phenyl group substituted with a halogen atom, more preferably a fluorinated phenyl group, and even more preferably a perfluorophenyl group.

[0112] When the fluorinated arylsulfonic acid polymer compound of the present invention contains a repeating unit represented by formula (F2), the content ratio of the unit of formula (F1) to the unit of formula (F2) is not particularly limited. However, in consideration of improving device characteristics when used as a dopant substance, the molar ratio of formula (F1):formula (F2) is preferably from 10:1 to 1:10, more preferably from 5:1 to 1:5, even more preferably from 3:1 to 1:3, and still more preferably 1:1.

[0113] The molecular weight of the fluorinated arylsulfonic acid polymer compound of the present invention is not particularly limited, but from the viewpoint of improving heat resistance and ensuring solubility in solvents, the weight average molecular weight Mw is preferably 1,000 to 50,000, more preferably 1,500 to 10,000, and even more preferably 2,000 to 10,000. The molecular weight distribution (Mw / Mn) is preferably 1 to 3, more preferably 1 to 2. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) using polyethylene oxide as a standard sample.

[0114] The fluorinated arylsulfonic acid polymer compound of the present invention can be obtained by polymerizing a monomer represented by the following formula (F1A) and, if necessary, a monomer represented by the following formula (F2A) in the presence of a solvent and a radical polymerization initiator by a known radical polymerization method. In this case, two or more types of monomers represented by formula (F1A) may be used in combination, and two or more types of monomers represented by formula (F2A) may be used in combination.

[0115] (In the formula, Ar F , Ar S , X and R f1 has the same meaning as above.)

[0116] In the present invention, in consideration of producing a charge-transporting thin film having excellent charge transport properties, it is preferable to use an aryl sulfonic acid compound, an aryl sulfonic acid ester compound, or a fluorinated aryl sulfonic acid polymer compound as the dopant substance, and in consideration of solubility in a solvent, it is more preferable to use an aryl sulfonic acid ester compound.

[0117] Furthermore, when the resulting thin film is used as a hole injection layer of an organic EL device, the charge transport varnish may contain an organosilane compound for the purpose of improving the injection property into the hole transport layer, improving the life characteristics of the device, etc. The content of the organosilane compound is usually about 1 to 30% by mass based on the total mass of the charge transport substance and the dopant substance.

[0118] The organic solvent used in preparing the charge-transporting varnish of the present invention can be a highly polar solvent that can dissolve the arylamine compound of the present invention well. The arylamine compound of the present invention can be dissolved in a solvent regardless of the polarity of the solvent. If necessary, a low-polarity solvent may be used because it has better process compatibility than a high-polarity solvent. In the present invention, a low-polarity solvent is defined as one having a dielectric constant of less than 7 at a frequency of 100 kHz, and a high-polarity solvent is defined as one having a dielectric constant of 7 or more at a frequency of 100 kHz.

[0119] 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, 1,4-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, dimethyl phthalate, bis(2-ethylhexyl) phthalate, dibutyl maleate, dibutyl oxalate, hexyl acetate, diisopropyl malonate, diethylene glycol monoethyl ether acetate and diethylene glycol monobutyl ether acetate.

[0120] Examples of highly polar solvents include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone; ketone solvents such as ethyl methyl ketone, isophorone, and cyclohexanone; cyano solvents such as acetonitrile and 3-methoxypropionitrile; polyhydric alcohol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, and 2,3-butanediol; monohydric 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; and sulfoxide solvents such as dimethyl sulfoxide.

[0121] The viscosity of the charge-transporting varnish is determined as appropriate depending on the thickness of the thin film to be produced and the solid content concentration, but is typically 1 to 50 mPa·s at 25°C. In the present invention, the solid content refers to the components contained in the charge-transporting varnish of the present invention other than the solvent. The solid content concentration of the charge-transporting varnish is determined as appropriate taking into account the viscosity and surface tension of the varnish, the thickness of the thin film to be produced, and the like, but is typically about 0.1 to 20.0% by mass. In consideration of improving the coatability of the varnish, it is preferably about 0.5 to 10.0% by mass, and more preferably about 1.0 to 5.0% by mass.

[0122] The method for preparing the charge-transporting varnish is not particularly limited, and examples thereof include a method in which all solid components, such as the charge-transporting substance including the arylamine compound of the present invention, are dissolved in an organic solvent at once, and a method in which a portion of the solid components is dissolved in an organic solvent and then the remaining solid components are dissolved.

[0123] In particular, when preparing a charge-transporting varnish, from the viewpoint of obtaining a thin film with higher flatness with good reproducibility, it is desirable to dissolve the charge-transporting substance, dopant substance, etc. in an organic solvent and then filter the resultant using a filter on the order of submicrometers.

[0124] The charge-transporting varnish described above can be used to easily produce a charge-transporting thin film, and is therefore suitable for use in producing electronic devices, particularly organic EL devices and quantum dot EL devices. In this case, the charge-transporting thin film can be formed by applying the charge-transporting varnish described above to a substrate and baking it. The method for applying the varnish is not particularly limited, and examples include dipping, spin coating, transfer printing, roll coating, brush coating, inkjet coating, spraying, and slit coating. It is preferable to adjust the viscosity and surface tension of the varnish depending on the application method.

[0125] Furthermore, the atmosphere in which the charge-transporting varnish is baked after application is not particularly limited, and a thin film with a uniform film surface and high charge transport properties can be obtained not only in an air atmosphere but also in an inert gas such as nitrogen or in a vacuum. However, depending on the type of dopant substance used, baking the varnish in an air atmosphere may reproducibly produce a thin film with higher charge transport properties.

[0126] The baking temperature is appropriately set within a range of about 100 to 260° C., taking into consideration the use of the resulting thin film, the degree of charge transport property to be imparted to the resulting thin film, the type and boiling point of the solvent, etc. When the resulting thin film is used as a hole injection layer of an organic EL device or a quantum dot EL device, the baking temperature is preferably about 140 to 250° C., and more preferably about 145 to 240° C. During baking, the temperature may be changed in two or more stages for the purpose of achieving more uniform film formation or promoting a reaction on the substrate, and heating may be performed using an appropriate device such as a hot plate or an oven.

[0127] The thickness of the charge transport thin film is not particularly limited, but is preferably 5 to 300 nm when used as a hole injection layer, hole transport layer, or hole injection transport layer in an organic EL device or a quantum dot EL device. Methods for changing the film thickness include changing the solids concentration in the varnish or changing the amount of solution (varnish amount) on the substrate during application.

[0128] When the charge transport thin film is applied to an organic EL device or a quantum dot EL device, the charge transport thin film can be disposed between a pair of electrodes constituting the organic EL device or the quantum dot EL device. Typical configurations of organic EL devices or quantum dot EL devices include, but are not limited to, the following (a) to (f). In the configurations described below, an electron blocking layer or the like can be disposed between the light-emitting layer and the anode, and a hole blocking layer or the like can be disposed between the light-emitting layer and the cathode, as necessary. Furthermore, the hole injection layer, the hole transport layer, or the hole injection transport layer may also function as an electron blocking layer, and the electron injection layer, the electron transport layer, or the electron injection transport layer may also function as a hole blocking layer. Furthermore, an optional functional layer can be disposed between each layer as necessary. (a) anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (b) anode / hole injection layer / hole transport layer / light-emitting layer / electron injection transport layer / cathode (c) anode / hole injection transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (d) anode / hole injection transport layer / light-emitting layer / electron injection transport layer / cathode (e) anode / hole injection layer / hole transport layer / light-emitting layer / cathode (f) anode / hole injection transport layer / light-emitting layer / cathode

[0129] The terms "hole injection layer," "hole transport layer," and "hole injection transport layer" refer to layers formed between the light-emitting layer and the anode, which have the function of transporting holes from the anode to the light-emitting layer. When only one layer of a hole-transporting material is provided between the light-emitting layer and the anode, it is the "hole injection transport layer." When two or more layers of a 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 "hole transport layers." In particular, the hole injection (transport) layer is a thin film that is excellent not only in the ability to accept holes from the anode but also in the ability to inject holes into the hole transport (light-emitting) layer. The terms "electron injection layer," "electron transport layer," and "electron injection transport layer" refer to layers formed between the light-emitting layer and the cathode, which transport electrons from the cathode to the light-emitting layer. When only one layer of an electron-transporting material is provided between the light-emitting layer and the cathode, it is the "electron injection transport layer." When two or more layers of an electron-transporting material are provided between the light-emitting layer and the cathode, the layer closest to the cathode is the "electron injection layer," and the remaining layers are "electron transport layers." The term "light-emitting layer" refers to an organic layer that emits light. When a doping system is employed, it contains a host material and a dopant material. In this case, the host material primarily promotes the recombination of electrons and holes and confines excitons within the light-emitting layer, while the dopant material efficiently emits the excitons obtained by recombination. In the case of phosphorescent devices, the host material primarily confines excitons generated by the dopant within the light-emitting layer.

[0130] The charge-transporting thin film prepared from the charge-transporting varnish of the present invention can be used as a functional layer such as a hole injection layer, a hole transport layer, or a hole injection transport layer provided between the anode and the light-emitting layer of an organic EL device or a quantum dot EL device, but as described above, it is usually suitable as a hole injection layer over which an upper layer is formed by a coating method.

[0131] Materials and methods for producing an organic EL device using the charge transport varnish of the present invention include, but are not limited to, those listed below. An example of a method for producing an OLED device having a hole injection layer made of a thin film obtained from the charge transport varnish is as follows. It is preferable to preliminarily clean the electrodes with alcohol, pure water, or the like, or to perform surface treatments such as UV ozone treatment or oxygen plasma treatment, to the extent that this does not adversely affect the electrodes. A hole injection layer is formed on an anode substrate using the charge transport varnish by the above-described method. This substrate is introduced into a vacuum deposition apparatus, 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 deposited by vapor deposition. Alternatively, instead of forming the hole transport layer and the light-emitting layer by vapor deposition in this method, these layers are formed by a wet process using a hole transport layer-forming composition containing a hole transport polymer and a light-emitting layer-forming composition containing a light-emitting polymer. If necessary, an electron blocking layer may be provided between the light-emitting layer and the hole transport layer.

[0132] Examples of 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, and preferably those that have undergone planarization treatment. Polythiophene derivatives and polyaniline derivatives with high charge transport properties can also be used. Other metals that can be used to make metal anodes include, but are not limited to, gold, silver, copper, indium, and alloys thereof.

[0133] Examples of materials for forming the hole transport layer include triarylamines such as (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimer, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (α-NPD), 4,4',4"-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), and 4,4',4"-tris[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA), and oligothiophenes such as 5,5"-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2"-terthiophene (BMA-3T).

[0134] Examples of materials for forming the light-emitting layer include, but are not limited to, low-molecular-weight light-emitting materials such as metal complexes (e.g., aluminum complexes of 8-hydroxyquinoline), metal complexes of 10-hydroxybenzo[h]quinoline, bisstyrylbenzene derivatives, bisstyrylarylene derivatives, metal complexes of (2-hydroxyphenyl)benzothiazole, and silole derivatives; and systems in which a light-emitting material and an electron transfer material are mixed with a polymer compound (e.g., poly(p-phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly(3-alkylthiophene), or polyvinylcarbazole. Furthermore, when the light-emitting layer is formed by vapor deposition, it may be co-deposited with a light-emitting dopant. Examples of light-emitting dopants include, but are not limited to, metal complexes (e.g., tris(2-phenylpyridine)iridium(III) (Ir(ppy)), naphthacene derivatives (e.g., rubrene), quinacridone derivatives, and fused polycyclic aromatic rings (e.g., perylene).

[0135] Examples of materials for forming the electron transport layer / hole blocking layer include, but are not limited to, oxydiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

[0136] Materials for forming the electron injection layer include, but are not limited to, metal oxides such as lithium oxide (LiO), magnesium oxide (MgO), and alumina (AlO), and metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF). Cathode materials include, but are not limited to, aluminum, magnesium-silver alloys, and aluminum-lithium alloys. Materials for forming the electron blocking layer include, but are not limited to, tris(phenylpyrazole)iridium.

[0137] Examples of hole transporting polymers include poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,1'-biphenylene-4,4-diamine)], poly[(9,9-bis{1'-penten-5'-yl}fluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-endcapped with Examples include polysilsesquioxane, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)], poly(9-vinylcarbazole), and poly(4-butyl-N,N-diphenylaniline).

[0138] 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'-ethylhexoxy)-1,4-phenylenevinylene) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

[0139] The quantum dot material may include at least one semiconductor material selected from the group consisting of II-VI semiconductors, III-V semiconductors, I-III-VI semiconductors, IV semiconductors, and I-II-IV-VI semiconductors. Specific examples of the semiconductor material include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, and CdHgZnT. e, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe; GaN, GaP, GaAs, G aSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, Ga InNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnS Examples of suitable gallium arsenide include, but are not limited to, Cu ...

[0140] The charge transporting thin film obtained from the charge transporting varnish of the present invention can be used as a functional layer such as a hole injection layer, a hole transport layer, or a hole injection transport layer provided between the anode and the light-emitting layer of an organic EL device or a quantum dot EL device. In addition, the charge transporting thin film can also be used as a charge transporting thin film in electronic devices such as organic photoelectric conversion devices, organic thin-film solar cells, organic perovskite photoelectric conversion devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic optical inspectors, organic photoreceptors, organic field quenching devices, light-emitting electrochemical cells, quantum lasers, organic laser diodes, and organic plasmon light-emitting devices.

[0141] 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. The apparatus and reagents used are as follows.

[0142] [Device] (1) 1 H-NMR: AVANCE III HD 500MHz Nuclear Magnetic Resonance Spectrometer, manufactured by Bruker (2) Substrate cleaning: Substrate cleaning device (low-pressure plasma method), manufactured by Choshu Sangyo Co., Ltd. (3) Application of charge transport varnish: Spin coater MS-A100, manufactured by Mikasa Co., Ltd. (4) Film thickness measurement: Micro-shape measuring instrument Surfcorder ET-4000, manufactured by Kosaka Laboratory Co., Ltd. (5) Fabrication of element: Multi-function deposition system C-E2L1G1-N, manufactured by Choshu Sangyo Co., Ltd. (6) Measurement of electrical properties of element: Multi-channel IVL measurement device, manufactured by EHC Co., Ltd.

[0143] [Reagents] 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole manufactured by Suna Tech Inc. Pd(dba)2 manufactured by Tokyo Chemical Industry Co., Ltd. Tri-tert-butylphosphonium tetrafluoroborate manufactured by Fujifilm Wako Chemical Co., Ltd. Lithium bis(trimethylsilyl)amide 1.0 mol / L toluene solution manufactured by Aldrich 2,7-dibromo-9,9-dimethyl-9H-fluorene manufactured by Tokyo Chemical Industry Co., Ltd. 4,4'-dibromo-1,1'-biphenyl manufactured by Tokyo Chemical Industry Co., Ltd. 2-bromo-9,9-dimethylfluorene manufactured by Tokyo Chemical Industry Co., Ltd. 5% Pd carbon powder (hydrated product) STD type manufactured by N.E. Chemcat Corporation 4,4'-Diamino-3,3',5,5'-tetramethylbiphenyl manufactured by Tokyo Chemical Industry Co., Ltd. RuPhos manufactured by Aldrich Toluene manufactured by Kanto Chemical Co., Ltd. Hexane manufactured by Kanto Chemical Co., Ltd. Ethyl acetate manufactured by Kanto Chemical Co., Ltd. Acetonitrile manufactured by Kanto Chemical Co., Ltd. Acetone manufactured by Kanto Chemical Co., Ltd. Methanol manufactured by Kanto Chemical Co., Ltd. Tetrahydrofuran manufactured by Kanto Chemical Co., Ltd. 1,4-Dioxane manufactured by Kanto Chemical Co., Ltd. Methylene chloride manufactured by Kanto Chemical Co., Ltd. Acetic acid manufactured by Kanto Chemical Co., Ltd. Nitric acid 1.42 manufactured by Kanto Chemical Co., Ltd. 1N hydrochloric acid aqueous solution manufactured by Kanto Chemical Co., Ltd. Sodium hydroxide manufactured by Junsei Chemical Co., Ltd. Ammonium chloride manufactured by Junsei Chemical Co., Ltd. Celite No. 545 manufactured by Fujifilm Wako Chemical Co., Ltd. Silica gel N60 manufactured by Kanto Chemical Co., Ltd.

[0144] 1 Chemical shift values ​​of H-NMR spectra are expressed in ppm, and deuterated chloroform (CDCl3), deuterated dimethyl sulfoxide (DMSO-d6), and deuterated tetrahydrofuran (THF-d8) were used as solvents. 1 In the H-NMR spectrum, signals derived from residual protons of the solvent were used, and the internal standards were set to chloroform at δ 7.26 ppm, dimethyl sulfoxide at δ 2.50 ppm, and tetrahydrofuran at δ 1.72 ppm.

[0145] [1] Synthesis of Compounds [Synthesis Example 1]: 9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-amine (Intermediate A)​

[0146] A side-arm flask was charged with 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole (15.0 g, 29.16 mmol), Pd(dba) (0.84 g, 1.46 mmol), and tri-tert-butylphosphonium tetrafluoroborate (0.42 g, 1.46 mmol), and the mixture was degassed to create a nitrogen atmosphere. Toluene (75 mL) was added, and lithium bis(trimethylsilyl)amide (toluene solution, 32.0 mL, 32.07 mmol) was slowly added with stirring. After 15 hours, TLC confirmed the disappearance of 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole. The reaction solution was cooled to 0°C, and 1N aqueous hydrochloric acid (20 mL) was added to adjust the pH to 3. The pH of the resulting solution was adjusted to 12 with a 2N aqueous solution of sodium hydroxide. This solution was filtered through KC floc by suction filtration and washed with toluene. After extraction with toluene, the organic layer was washed with water. This organic layer was distilled off to obtain a crude product. The obtained crude product was dissolved in toluene (5 mL), and the solution was added dropwise to hexane (300 g). The precipitated solid was filtered and dried to obtain intermediate A (orange solid, 10.81 g, yield 82%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (CDCl3, 500Hz): δ 8.39 (1H, d, J = 1.5Hz), 8.22 (1H, d, J = 7.7Hz), 7.71-7.59 (8H, m), 7.55 (1H, d, J = 8.0Hz), 7.48 (2H, d, J = 8.6Hz), 7.4 4-7.42 (2H, m), 7.33-7.30 (1H, m), 6.80 (1H, d, J = 2.0Hz), 6.69 (1H, dd, J = 2.1Hz, 8.0Hz), 3.78 (2H, s), 1.27 (6H, s).

[0147] [Example 1-1]: Synthesis of bis(9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl)amine (Compound 1)

[0148] Intermediate A (5.00 g, 11.1 mmol), 3-(7-bromo9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole (3.81 g, 7.40 mmol), Pd(dba) (0.064 g, 0.111 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.064 g, 0.222 mmol), sodium tert-butoxide (1.42 g, 14.8 mmol), and toluene (150 mL) were added to a side-arm flask, and the reaction vessel was degassed and replaced with a nitrogen atmosphere. The resulting mixture was heated to 100°C and stirred for 24 hours, after which the reaction mixture was allowed to cool. The reaction mixture was suction filtered using Celite 545, and the Celite 545 was washed with toluene. The resulting filtrate was washed successively with water and saturated brine. The washed solution was subjected to suction filtration using SiO2, and the SiO2 was washed with toluene. The obtained solution was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 4 / 1 → 2 / 1 → 1 / 1). The obtained solution was concentrated under reduced pressure to obtain an oily substance. 3 g of toluene was added to the oily substance, and the mixture was added dropwise to 100 g of acetonitrile. After stirring for a while, the mixture was subjected to suction filtration to obtain Compound 1 (brown solid, yield 4.70 g, 72%). 1 The H-NMR spectrum is shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.66 (2H, s), 8.54 (1H, s), 8.40 (2H, d, J = 7.6Hz), 7.95 (2H, s), 7.83 (2H , d, J=8.6Hz), 7.80 (2H, d, J=7.8Hz), 7.76-7.71 (8H, m), 7.68 (4H, d, J=7 .8Hz), 7.57 (2H, t, J = 14.3Hz, 7.1Hz), 7.48-7.45 (4H, m), 7.41 (2H, d, J = 8.2), 7.35-7.33 (4H, m), 7.25 (2H, t, J = 14.8Hz, 7.5Hz), 1.55 (12H, s).

[0149] [Example 1-2]: N 2 , N 7Synthesis of bis[9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl]-9,9-dimethyl-9H-fluorene-2,7-diamine (Compound 2)

[0150] Intermediate A (2.00 g, 4.43 mmol), 2,7-dibromo-9,9-dimethyl-9H-fluorene (0.52 g, 1.48 mmol), Pd(dba) (0.025 g, 0.044 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.025 g, 0.089 mmol), sodium tert-butoxide (0.710 g, 7.40 mmol), and toluene (30 mL) were added to a side-arm flask, and the reaction vessel was degassed and replaced with a nitrogen atmosphere. The resulting mixture was heated to 100°C and stirred with heating for 6 hours, after which the reaction solution was allowed to cool. The reaction solution was suction filtered using Celite 545, and the Celite 545 was washed with toluene. The resulting filtrate was washed sequentially with water and saturated brine. The washed solution was suction filtered using SiO, and the SiO was washed with toluene. The obtained filtrate was concentrated under reduced pressure, and the solvent was removed until the solution became 5 g. The obtained solution was added dropwise to 150 g of acetonitrile, stirred for a while, and then subjected to suction filtration. The obtained solid was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 4 / 1). The obtained solution was concentrated under reduced pressure to obtain an oily substance. 2 g of ethyl acetate was added to the oily substance, and the mixture was added dropwise to 50 g of acetonitrile, stirred for a while, and then subjected to suction filtration to obtain Compound 2 (light green solid, yield 403.0 mg, 25%). 1 The results of H-NMR measurement are shown below. 1H-NMR (DMSO-d6, 500Hz): δ 8.66 (2H, s), 8.42 (2H, s), 8.40 (2H, d, J=7.8Hz), 7.94 (2H, s), 7.83 (2H, d, J=8. 6Hz), 7.78 (2H, d, J = 7.8Hz), 7.72 (8H, t, J = 14.9Hz, 7.5Hz), 7.68 (4H, d, J = 7.8H z), 7.61-7.56 (4H, m), 7.48-7.45 (4H, m), 7.41 (2H, d, J = 8.2Hz), 7.33 (2H, t, J = 14.6Hz, 7.3Hz), 7.28 (4H, s), 7.09 (4H, d, J=8.0Hz), 1.53 (12H, s), 1.45 (6H, s).

[0151] [Example 1-3]: N 4 , N 4’ Synthesis of bis[9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl]-[1,1'-biphenyl]-4,4'-diamine (Compound 3)

[0152] Compound 3 was obtained in the same manner as in Example 1-2, except that 4,4'-dibromo-1,1'-biphenyl (0.46 g, 1.48 mmol) was used instead of 2,7-dibromo-9,9-dimethyl-9H-fluorene (light yellow solid, yield: 428.1 mg, 28%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.66 (2H, s), 8.44 (2H, s), 8.40 (2H, d, J = 7.7Hz), 7.94 (2H, s), 7.83 (2H, d, J = 8 .6Hz), 7.79 (2H, d, J = 7.8Hz), 7.72 (8H, t, J = 8.2Hz), 7.68 (4H, d, J = 7.8Hz), 7.5 7 (6H, d, J = 8.1Hz), 7.48-7.45 (4H, m), 7.41 (2H, d, J = 8.2Hz), 7.33 (2H, t, J = 7. 3Hz), 7.28 (2H, s), 7.21 (4H, d, J=8.1Hz), 7.13 (2H, d, J=8.2Hz), 1.55 (12H, s).

[0153] [Synthesis Example 2]: Synthesis of 2-bromo-9,9-dimethyl-7-nitro-9H-fluorene (Intermediate B)

[0154] 2-Bromo-9,9-dimethylfluorene (22.2 g, 81.3 mmol) and acetic acid (400 mL) were added to a reaction vessel and heated to 50°C. 2-Bromo-9,9-dimethylfluorene was dissolved, and 1.42 g (110 mL) of nitric acid was slowly added dropwise to the solution. The resulting mixture was heated to 85°C and stirred under heat for 3 hours. The reaction mixture was then cooled to 0°C with ice water. The reaction mixture was added to 500 g of ice and stirred for 15 minutes. The mixture was suction filtered, and the resulting solid was washed with water. The resulting solid was recrystallized from toluene and dried to obtain Intermediate B (light yellow solid, yield 22.3 g, 86%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.49 (1H, s), 8.28 (1H, d, J = 8.4Hz), 8.14 (1H, d, J = 8.4Hz), 7.99 (1H, d, J = 8.1Hz), 7.95 (1H, s), 7.64 (1H, d, J = 8.1Hz), 1.53 (6H, s).

[0155] [Synthesis Example 3]: Synthesis of N-[9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl]-9,9-dimethyl-7-nitro-9H-fluoren-2-amine (Intermediate C)

[0156] Intermediate A (5.00 g, 11.10 mmol), Intermediate B (2.94 g, 9.25 mmol), Pd(dba) (0.27 g, 0.46 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.20 g, 0.69 mmol), sodium tert-butoxide (1.33 g, 13.87 mmol), and toluene (120 mL) were added to a side-arm flask, and the reaction vessel was degassed and replaced with a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 15 hours. The reaction solution was suction filtered through Celite 545, and the Celite 545 was washed with toluene. The resulting filtrate was washed sequentially with water and saturated brine. The washed solution was suction filtered through SiO, and the SiO was washed with toluene. The resulting filtrate was concentrated under reduced pressure, and the solvent was removed until the solution became 5 g. The resulting solution was added dropwise to 100 g of methanol, stirred for a while, and then suction filtered. The obtained solid was added to 100 g of acetonitrile and dissolved by heating to 80° C. The solution was filtered, and the filtrate was concentrated under reduced pressure to obtain intermediate C (reddish-brown solid, yield: 5.15 g, 67%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.80 (1H, s), 8.67 (1H, s), 8.41-8.39 (2H, m), 8.23 ​​(1H, d, J = 8.4Hz), 7.96 (1H, s), 7.89 (2H, q, J = 11.4Hz, 8.6Hz), 7.83 (2H, t, J = 15.5Hz, 8.2Hz), 7.79 (1H, d, J = 8.1Hz), 7.75 (1H, d, J = 8.8Hz), 7.7 2 (2H, d, J = 7.5Hz), 7.68 (2H, d, J = 7.9Hz), 7.57 (1H, t, J = 14.3Hz, 7.3Hz), 7.48-7.45 (2H, m), 7.4 2 (1H, d, J=8.2Hz), 7.37 (1H, s), 7.35-7.32 (2H, m), 7.17-7.12 (2H, m), 1.55 (6H, s), 1.50 (6H, s).

[0157] [Synthesis example 4]: N 2 Synthesis of -(9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl)-9,9-dimethyl-9H-fluorene-2,7-diamine (Intermediate D)

[0158] Intermediate C (2.00 g, 2.91 mmol) and 10 mL of tetrahydrofuran were added to a side-arm flask, and the reaction vessel was degassed and a nitrogen atmosphere was created. 5% Pd carbon powder (hydrated product) STD type (0.2 g) was added thereto, and the reaction vessel was degassed, then a hydrogen atmosphere was created, and the mixture was stirred at room temperature for 18 hours. After the reaction vessel was degassed and a nitrogen atmosphere was created, 2 g of Celite 545 was added to the reaction solution and stirred. The mixture was suction filtered using Celite 545, and the Celite 545 was washed with tetrahydrofuran. The resulting filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: toluene → toluene / acetone = 19 / 1) to obtain Intermediate D (orange solid, yield 1.86 g, 97%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.65 (1H, d, J = 1.6Hz), 8.40 (1H, d, J = 7.7Hz), 8.30 (1H, s), 7.92 (1H, d, J = 1.1Hz), 7.82 (1H, dd , J=8.6Hz, 1.8Hz), 7.75 (1H, t, J=15.1Hz, 7.8Hz), 7.73-7.66 (6H, m), 7.58-7.55 (1H, m), 7.48 -7.45 (3H, m), 7.41 (1H, d, J=8.2Hz), 7.35-7.32 (2H, m), 7.23-7.22 (2H, m), 7.05-7.02 (2H, m) , 6.67 (1H, d, J = 1.9Hz), 6.52 (1H, dd, J = 8.0Hz, 2.0Hz), 5.10 (2H, s), 1.52 (6H, s), 1.37 (6H, s).

[0159] [Example 1-4]: N 2 , N 2’ -(9,9-dimethyl-9H-fluorene-2,7-diyl)bis{N 7 Synthesis of -[9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl]-9,9-dimethyl-9H-fluorene-2,7-diamine} (Compound 4)

[0160] Intermediate D (1.56 g, 2.38 mmol), 2,7-dibromo-9,9-dimethyl-9H-fluorene (0.28 g, 0.79 mmol), Pd(dba) (0.046 g, 0.079 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.035 g, 0.12 mmol), sodium tert-butoxide (0.23 g, 2.38 mmol), and toluene (20 mL) were added to a side-arm flask, and the reaction vessel was degassed and replaced with a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 15 hours. The reaction solution was suction filtered using Celite 545, and the Celite 545 was washed with toluene. The resulting filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: toluene) to obtain Compound 4 (yellow solid, yield 336.0 mg, 28%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.65 (2H, s), 8.40 (4H, d, J = 7.6Hz), 8.29 (2H, s), 7.93 (2H, s), 7.83 (2H, dd, J=8.6Hz, 1.5Hz), 7.77 (2H, d, J=7.9Hz), 7.73-7.70 (8H, m), 7.67 (4H, d, J=7. 1Hz), 7.58-7.55 (8H, m), 7.47-7.45 (4H, m), 7.41 (2H, d, J = 8.2Hz), 7.33 (2H, t, J = 15.1Hz, 7.4Hz), 7.27 (4H, s), 7.23 (4H, s), 7.09-7.03 (8H, m), 1.53 (12H, s), 1.43 (12H, s), 1.42 (6H, s).

[0161] [Comparative Example 1-1]: N 4 , N 4’ Synthesis of bis[9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl]-3,3',5,5'-tetramethyl-[1,1'-biphenyl]-4,4'-diamine (Comparative Compound 1)

[0162] Intermediate A (1.35 g, 2.62 mmol), 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl (0.30 g, 1.25 mmol), Pd(dba) (0.046 g, 0.079 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.054 g, 0.187 mmol), sodium tert-butoxide (0.30 g, 3.12 mmol), toluene (20 mL), and tetrahydrofuran (10 mL) were added to a side-arm flask, and the reaction vessel was degassed and replaced with a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 20 hours. The reaction solution was suction filtered using Celite 545, and the Celite 545 was washed with toluene. The filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: toluene) to obtain comparative compound 1 (pale green solid, yield 1.14 g, 83%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (DMSO-d6, 500Hz): δ 8.64 (2H, d, J = 1.4Hz), 8.41 (2H, d, J = 4.6Hz), 7.89 (2H, s), 7.81 (2H, dd, J = 1.5Hz , 8.6Hz), 7.74-7.67 (10H, m), 7.62-7.53 (8H, m), 7.46 (4H, d, J=8.3Hz), 7.41 (2H, d, J = 8.2Hz), 7.33 (2H, t, J = 7.5Hz, 14.4Hz), 7.25 (2H, t, J = 7.5Hz, 15.0Hz), 7.18 ( 2H, d, J = 6.5Hz), 6.68 (2H, s), 6.45 (2H, d, J = 9.4Hz), 2.28 (12H, s), 1.48 (12H, s).

[0163] [Comparative Example 1-2]: N 4 , N 4 , N 4’ , N 4’ Synthesis of tetrakis(9,9-dimethyl-7-(9-phenyl-9H-carbazol-3-yl)-9H-fluoren-2-yl)-3,3',5,5'-tetramethyl-[1,1'-biphenyl]-4,4'-diamine (Comparative Compound 2)

[0164] Intermediate A (0.216 g, 4.20 mmol), 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl (0.240 g, 1.00 mmol), Pd(dba)2 (0.115 g, 0.20 mmol), RuPhos (0.140 g, 0.30 mmol), LiHMDS (toluene solution, 4.4 mL, 4.4 mmol), and 20 mL of 1,4-dioxane were placed in a side-arm flask, and the reaction vessel was degassed and replaced with a nitrogen atmosphere. The resulting mixture was heated to 90°C and stirred for 20 hours, after which the reaction mixture was allowed to cool. 100 mL of saturated aqueous ammonium chloride and 100 mL of a mixed organic solvent (ethyl acetate / tetrahydrofuran = 2 / 1) were added to the reaction mixture, and the layers were separated. The resulting organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The anhydrous sodium sulfate was filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (developing solvent: methylene chloride) to obtain comparative compound 2 (orange solid, yield: 1.76 g, 89%). 1 The results of H-NMR measurement are shown below. 1 H-NMR (THF-d8, 500Hz): δ 8.50 (4H, s), 8.25 (4H, d, J = 7.7Hz), 7.84 (4H, s), 7.75 (8H, d, J = 8.1Hz), 7.70 (4H, d, J = 7.9Hz), 7.66-7.64 (20H, m), 7.60 (4H, s), 7.49-7.46 (8H, m), 7.41-7.38 (12H, m), 7.25 (4H, t, J = 14.3Hz, 7.4Hz), 6.95 (4H, d, J = 8.3Hz), 2.22 (12H, s), 1.54 (24H, s).

[0165] [2] Preparation of Charge-Transporting Varnish [Example 2-1] Preparation of Charge-Transporting Varnish 1 Compound 1 (170 mg, 0.192 mmol) and arylsulfonic acid ester A (480 mg, 0.385 mmol) represented by the following formula, synthesized according to the method described in WO 2017 / 217455, were dissolved in a mixed solvent of triethylene glycol butyl methyl ether (4.68 g), diisopropyl malonate (2.80 g), and dimethyl phthalate (1.87 g) with stirring at room temperature. The resulting solution was filtered using a PP filter with a pore size of 0.2 μm to obtain Charge-Transporting Varnish 1.

[0166]

[0167] Example 2-2 Preparation of Charge-Transporting Varnish 2 Charge-transporting varnish 2 was obtained in the same manner as in Example 2-1, except that compound 2 (198 mg, 0.181 mmol) was used instead of compound 1, and arylsulfonic acid ester A (452 ​​mg, 0.363 mmol) was used.

[0168] Example 2-3 Preparation of Charge-Transporting Varnish 3 Charge-transporting varnish 3 was obtained in the same manner as in Example 2-1, except that compound 3 (193 mg, 0.183 mmol) was used instead of compound 1, and arylsulfonic acid ester A (457 mg, 0.367 mmol) was used.

[0169] Example 2-4 Preparation of Charge-Transporting Varnish 4 Charge-transporting varnish 4 was obtained in the same manner as in Example 2-1, except that compound 4 (245 mg, 0.162 mmol) was used instead of compound 1, and arylsulfonic acid ester A (405 mg, 0.325 mmol) was used.

[0170] Comparative Example 2-1 Preparation of Charge-Transporting Varnish 5 Charge-transporting varnish 5 was obtained in the same manner as in Example 2-1, except that comparative compound 1 (200 mg, 0.180 mmol) was used instead of compound 1, and arylsulfonic acid ester A (450 mg, 0.361 mmol) was used.

[0171] Comparative Example 2-2 Preparation of Charge-Transporting Varnish 6 Charge-transporting varnish 6 was obtained in the same manner as in Example 2-1, except that comparative compound 2 (287 mg, 0.145 mmol) was used instead of compound 1, and arylsulfonic acid ester A (363 mg, 0.291 mmol) was used.

[0172] [3] Fabrication and Characterization of Hole-Only Device (HOD) [Example 3-1] Charge-transporting varnish 1 was applied to an ITO substrate using a spin coater, and then pre-baked in an air atmosphere at 120°C for 1 minute, followed by final baking at 230°C for 15 minutes to form a 65 nm thin film on the ITO substrate. The ITO substrate used was a 25 mm x 25 mm x 0.7 mm glass substrate with a patterned ITO film of 150 nm thickness formed on its surface. Prior to use, impurities on the surface were removed using an O2 plasma cleaning device (150 W, 30 seconds). A vapor deposition device (vacuum degree 1.0 x 10 -5 A thin film of α-NPD having a thickness of 30 nm was formed on the film at a rate of 0.2 nm / second using a vapor deposition apparatus (vacuum degree 1.0×10 -5 An 80 nm thick aluminum thin film was formed using a vacuum evaporation method (UV-1000) at a rate of 0.2 nm / sec using a vacuum evaporation method (UV-1000). Thereafter, the device was sealed with a sealing substrate to prevent deterioration of characteristics due to the influence of oxygen, water, etc. in the air. Sealing was performed using the following procedure. In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -76°C or less, the HOD was placed between the sealing substrates, and the sealing substrates were bonded together with an adhesive (Moresco Moisture Cut WB90US(P) manufactured by MORESCO Corporation). At this time, a water-repellent (HD-071010W-40 manufactured by Dynic Co., Ltd.) was placed inside the sealing substrate together with the organic EL device. The bonded sealing substrates were irradiated with UV light (wavelength: 365 nm, irradiation dose: 6,000 mJ / cm). 2 After that, the adhesive was cured by annealing at 80° C. for 1 hour, which was used as a hole-only device (HOD).

[0173] Examples 3-2 to 3-4, Comparative Examples 3-1 to 3-2 HOD was obtained in the same manner as in Example 3-1, except that Charge Transporting Varnishes 2 to 6 were used instead of Charge Transporting Varnish 1.

[0174] The current density was measured at a driving voltage of 3 V for the HODs produced in Examples 3-1 to 3-4 and Comparative Examples 3-1 and 3-2. The results are shown in Table 1.

[0175]

[0176] As shown in Table 1, the thin films prepared from the charge-transporting varnish of the present invention exhibited good charge-transporting properties.

Claims

1. An arylamine compound represented by the following formula (1): [In the formula, X 1 each independently represents a single bond or a group represented by any one of the following formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a3-1) to (a3-4), and (a4) to (a9); 2 each independently represents a group represented by any one of the following formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a3-1) to (a3-4), and (a4) to (a9), (In the formula, R 1 Each independently represents an alkyl group having 1 to 20 carbon atoms. The dashed line represents a bond. 1 each independently represents a group represented by the following formula (b1) or (b2): wherein Y is NZ 3 , O or S; Z 1 , Z 2 and Z 3 each independently represents a group represented by any one of the following formulas (c1) to (c4): The dashed line represents a bond. (In the formula, the dashed line represents a bond.) n represents an integer of 0 to 5. However, when n is 0, X 1 does not become a single bond.] 2. Above X 1 are each independently a single bond or a group represented by any one of the above formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a4) and (a7), 2 are each independently a group represented by any one of the above formulas (a1-1) to (a1-2), (a2-1) to (a2-4), (a4) and (a7).

3. The above Ar 1 The arylamine compound according to claim 1, wherein is a group represented by the above formula (b1).

4. R above 1 The arylamine compound according to claim 1, wherein each of the groups independently represents an alkyl group having 1 to 4 carbon atoms.

5. The above Y is NZ 3 The arylamine compound according to claim 1, wherein 6. Z above 1 , Z 2 and Z 3 The arylamine compound according to claim 1, wherein is a group represented by the above formula (c1).

7. A charge transporting material comprising the arylamine compound according to any one of claims 1 to 6.

8. A charge transporting varnish comprising the arylamine compound according to any one of claims 1 to 6 and an organic solvent.

9. The charge transporting varnish of claim 8, further comprising a dopant material.

10. A charge transporting thin film obtained from the charge transporting varnish according to claim 8.

11. An electronic device comprising the charge transporting thin film according to claim 10.

12. The electronic device according to claim 11, wherein said charge transporting thin film is a hole injection layer or a hole transport layer.

13. The electronic device according to claim 12, which is an organic EL device or a quantum dot EL device.