Organic electroluminescent element

Abstract

The present invention addresses the problem of providing a material for an organic electroluminescent element, the material having outstanding positive hole injection / transport performance, electron blocking ability, as well as stability and durability in the form of a thin film; and also providing an organic electroluminescent element which has high efficiency, low drive voltage, and a long lifespan by combining the aforementioned material and various materials for an organic EL element, the various materials having outstanding positive hole injection / transport performance, electron blocking ability, as well as stability and durability in the form of a thin film, in a manner in which the characteristics of the respective materials can be exhibited effectively.　Focusing on the fact that a triarylamine compound having a specific structure has outstanding positive hole injection / transport performance as well as stability and durability in the form of a thin film, an organic electroluminescent element was produced by selecting a specific arylamine compound as a material constituting a second positive hole transport layer, and the present invention was achieved.

Description

organic electroluminescence element

[0001] The present invention relates to an organic electroluminescence element (hereinafter abbreviated as organic EL element) which is a self-luminous element suitable for various display devices, and more particularly to an organic EL element using a specific arylamine compound.

[0002] Organic EL elements are self-luminous elements, and therefore are brighter and more visible than liquid crystal elements, and are capable of producing clearer displays, and therefore have been the subject of vigorous research.

[0003] In 1987, C. W. Tang et al. of Eastman Kodak Company made organic EL devices practical by developing a layered structure element in which various roles are assigned to each material. They layered a phosphor capable of transporting electrons and an organic material capable of transporting holes, and emitted light by injecting both charges into the phosphor layer, achieving 1000 cd / m at a voltage of 10 V or less. ２ Such high brightness is achieved (see, for example, Patent Documents 1 and 2).

[0004] To date, many improvements have been made to the practical application of organic EL elements, and the various roles of the laminated structure have been further subdivided, and high efficiency and durability have been achieved by electroluminescent elements in which an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode are provided in this order on a substrate (see, for example, Non-Patent Document 1).

[0005] Furthermore, attempts have been made to utilize triplet excitons in order to further improve luminous efficiency, and the use of phosphorescent compounds has been investigated (see, for example, Non-Patent Document 2). Furthermore, devices utilizing luminescence due to thermally activated delayed fluorescence (TADF) have also been developed. In 2011, Adachi et al. of Kyushu University achieved an external quantum efficiency of 5.3% using a device using a thermally activated delayed fluorescence material (see, for example, Non-Patent Document 3).

[0006] The light-emitting layer can also be prepared by doping a charge-transporting compound, generally called a host material, with a fluorescent compound, a phosphorescent compound, or a material that emits delayed fluorescence. As described in the aforementioned non-patent document, the selection of organic materials in an organic EL device significantly affects various properties of the device, such as efficiency and durability (see, for example, non-patent document 2).

[0007] In organic EL devices, charges injected from both electrodes recombine in the light-emitting layer to emit light. However, it is important to efficiently transfer both charges (holes and electrons) to the light-emitting layer, and therefore it is necessary to achieve a device with excellent carrier balance. Furthermore, by improving hole injection properties and electron blocking properties that block electrons injected from the cathode, the probability of holes and electrons recombining can be improved, and by further confining excitons generated in the light-emitting layer, high luminous efficiency can be achieved. Therefore, the role played by hole transport materials is important, and hole transport materials with high hole injection properties, high hole mobility, high electron blocking properties, and high durability against electrons are required.

[0008] Furthermore, the heat resistance and amorphous nature of the material are also important factors in determining the lifespan of the element. Materials with low heat resistance will undergo thermal decomposition even at low temperatures due to the heat generated when the element is in operation, causing the material to deteriorate. Materials with low amorphous nature will undergo crystallization of the thin film even in a short period of time, causing the element to deteriorate. For this reason, the materials used must have high heat resistance and good amorphous nature.

[0009] N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine (NPD) and various aromatic amine derivatives have been known to be hole transport materials used in organic EL devices (see, for example, Patent Document 1 and Patent Document 2). NPD has good hole transport ability, but its glass transition point (Tg), which is an index of heat resistance, is low at 96°C, and crystallization occurs under high temperature conditions, resulting in a deterioration of device characteristics (see, for example, Non-Patent Document 4). In addition, among the aromatic amine derivatives described in the above patent documents, there are those with a hole mobility of 10 －３ cm ２Although compounds having excellent mobility of .gtoreq..Vs / Vs or more are known (see, for example, Patent Documents 1 and 2), their electron blocking properties are insufficient, so that some electrons pass through the light-emitting layer, preventing improvement in luminous efficiency. For this reason, in order to further improve efficiency, a material with higher electron blocking properties, more stable thin films, and high heat resistance has been desired. Also, although highly durable aromatic amine derivatives have been reported (see, for example, Patent Document 3), they were used as charge transport materials in electrophotographic photoreceptors, and there have been no examples of their use in organic EL devices.

[0010] Arylamine compounds having a substituted carbazole structure have been proposed as compounds with improved properties such as heat resistance and hole injection properties (see, for example, Patent Documents 4 and 5). However, in devices using these compounds in the hole injection layer or hole transport layer, although the heat resistance and luminous efficiency have been improved, they are still not sufficient, and further reduction in driving voltage and further improvement in luminous efficiency are required.

[0011] To improve the device characteristics of organic EL devices and increase the device production yield, there is a demand for devices that can recombine holes and electrons with high efficiency, have high luminous efficiency, low driving voltage, and have a long life, by combining materials that have excellent hole and electron injection and transport properties, and have excellent thin film stability and durability.

[0012] Furthermore, in order to improve the device characteristics of organic EL devices, there is a demand for devices with a good carrier balance, high efficiency, low driving voltage, and long life, which can be achieved by combining materials that have excellent hole and electron injection and transport properties, as well as thin film stability and durability.

[0013] US5792557US5639914US7799492 B2US8021764 B2US8394510 B2US10818844 B2International Publication No. 2014 / 009310US2019 / 0140177 A1

[0014] Proceedings of the 9th Seminar of the Society of Applied Physics, pp. 55-61 (2001); Proceedings of the 9th Seminar of the Society of Applied Physics, pp. 23-31 (2001); Appl. Phys. Lett., 98, 083302 (2011); Proceedings of the 3rd Regular Meeting of the Organic EL Discussion Society, pp. 13-14 (2006)

[0015] The object of the present invention is to provide a material for organic EL devices having high efficiency and high durability, which is excellent in hole injection / transport performance, electron blocking ability, stability in a thin film state, and durability, and further to provide an organic EL device having high efficiency, low driving voltage, and long life by combining the material with various materials for organic EL devices having excellent hole and electron injection / transport performance, electron blocking ability, stability in a thin film state, and durability so that the properties of each material can be effectively exhibited.

[0016] The physical properties that the materials used in the organic EL devices to be provided by the present invention should have include (1) good hole injection properties, (2) high hole mobility, (3) a stable thin film state, and (4) excellent heat resistance. Furthermore, the physical properties that the organic EL devices to be provided by the present invention should have include (1) high luminous efficiency and power efficiency, (2) low luminous onset voltage, (3) low practical driving voltage, and (4) long life.

[0017]

[0006] In order to achieve the above object, the present inventors have conducted extensive research and have found that arylamine compounds having a specific structure have excellent hole injection / transport capabilities, thin film stability, and durability, and that selecting these as materials for a hole transport layer can efficiently transport holes injected from the anode side. Furthermore, the present inventors have produced various organic EL devices by combining light-emitting materials having specific structures, and have evaluated the device characteristics, which has led to the completion of the present invention.

[0018] That is, the present invention provides the following organic EL device: 1) An organic EL device having a multilayer structure including, from the anode side, at least a first hole transport layer, a second hole transport layer, a blue light-emitting layer, and an electron transport layer, in this order, between an anode and a cathode, and having, between the first hole transport layer and the electron transport layer, a layer containing a triarylamine compound represented by the following general formula (1):

[0019]

[0020] In general formula (1), R １and R ２ may be the same or different, and are groups represented by the following general formula (2-1) or (2-2), one of which is a group represented by the following general formula (2-1). M is a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a thiol group, a hydroxy group, a substituted or unsubstituted linear or branched alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms, a substituted or unsubstituted linear or branched alkenyl group having 2 to 6 carbon atoms, a substituted or unsubstituted linear or branched alkyloxy group having 1 to 6 carbon atoms, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted silyl group, or a substituted or unsubstituted boron group. n is an integer of 0 to 4, and when n is 2 or greater, M's may be the same or different from each other, and adjacent M's may be linked to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted nitrogen atom to form a ring.

[0021]

[0022]

[0023] In general formulas (2-1) and (2-2), L is a linking group and represents a substituted or unsubstituted divalent aromatic hydrocarbon group or a substituted or unsubstituted divalent aromatic heterocyclic group. m is an integer of 0 to 4. When m is 0, L represents a single bond. When m is 2 or more, Ls may be the same or different. Ar １ and Ar ２ may be the same or different and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group; Ar ３ represents a substituted or unsubstituted aromatic hydrocarbon group.

[0024] 2) The organic EL device according to 1), wherein the layer containing the triarylamine compound represented by the general formula (1) is a second hole transport layer.

[0025] 3) In the general formula (1), R１ is the general formula (2-1), and R ２ is the general formula (2-2),

[0026] 4) In the general formula (1), R １ is the general formula (2-2), and R ２ is the general formula (2-1).

[0027] 5) The organic EL device according to any one of 1) to 4), wherein the blue light-emitting layer contains a pyrene derivative having a pyrene skeleton in the molecule.

[0028] 5) The organic EL device according to any one of 1) to 4), wherein the blue light-emitting layer contains a compound represented by the following general formula (3-1) or (3-2):

[0029]

[0030]

[0031] In the general formulas (3-1) and (3-2), Q １ , Q ２ and Q ３ may be the same or different and represent a substituted or unsubstituted aromatic hydrocarbon or a substituted or unsubstituted aromatic heterocycle. ２ represents B, P, P=O, or P=S. １ , Y ２ and Y ３ may be the same or different, and N-R ３ , C-R ４ R ５ , O, S, Se, or Si—R ６ R ７ represents R ３ , R ４ , R ５ , R ６ and R ７may be the same or different, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group of 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms which may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group of 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group. ４ and R ５ , R ６ and R ７ may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group to form a ring, and Y １ , Y ２ and Y ３ But N-R ３ , C-R ４ R ５ , or Si—R ６ R ７ In the case of ３ , R ４ , R ５ , R ６ and R ７ are the adjacent Q １ , Q ２ or Q ３ and may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group to form a ring.

[0032] 7) The organic EL device according to any one of 1) to 4), wherein the blue light-emitting layer contains an anthracene derivative having an anthracene skeleton in the molecule.

[0033] X in the general formulas (3-1) and (3-2) represents B, P, P═O, or P═S. B is defined as a boron atom, P as a phosphorus atom, P═O as a phosphorus atom double-bonded to an oxygen atom, and P═S as a phosphorus atom double-bonded to a sulfur atom.

[0034] Y in the general formulas (3-1) and (3-2) １ ~Y ３ may be the same or different, and N-R ３ , C-R ４ R ５ , O, S, Se, or Si—R ６ R ７ Represents N-R ３ is R ３ a nitrogen atom having as a substituent C—R ４ R ５ is R ４ and R ５ as a substituent, O is an oxygen atom, S is a sulfur atom, Se is a selenium atom, and Si—R ６ R ７ is R ６ and R ７ is defined as a silicon atom having as a substituent.

[0035] M and Ar in the general formulae (1), (3-1) and (3-2) １ ~Ar ３ , Q １ ~Q ３ and R ３ ~R ７Specific examples of the "aromatic hydrocarbon group" or "aromatic heterocyclic group" in the "substituted or unsubstituted aromatic hydrocarbon group" or "substituted or unsubstituted aromatic heterocyclic group" represented by the formula (I) include a phenyl group, a biphenyl group, a terphenyl group, a stilbene group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a perylenyl group, a tetracenyl group, a thionyl group, a fluorenyl group, a spirofluorenyl group, a furanyl group, a pyronyl group, a thionyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a triazolyl group, a pyridyl group, a pyrimidyl group, a triazinyl group, an acridinyl group, a pyridazinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a Examples of the alkyl group include an aryl group, a quinazolinyl group, a quinoxalinyl group, a phthalazinyl group, a pyridomyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzimidazolyl group, a benzothiazolyl group, a benzocarbazolyl group, a benzothionyl group, a benzofuranyl group, a dibenzothionyl group, a dibenzofuranyl group, a phenanthronyl group, a thiazolyl group, an isoxazolyl group, an oxadiazolyl group, a thiadiazolyl group, a phenoxazinyl group, a phenothiazinyl group, and a carbolinyl group, and further examples include groups selected from aryl groups having 6 to 30 carbon atoms and heteroaryl groups having 2 to 20 carbon atoms.

[0036] Specific examples of the "aromatic hydrocarbon" or "aromatic heterocycle" of the "substituted or unsubstituted aromatic hydrocarbon" or "substituted or unsubstituted aromatic heterocycle" in the "divalent group of a substituted or unsubstituted aromatic hydrocarbon or a substituted or unsubstituted aromatic heterocycle" represented by L in the general formulae (2-1) and (2-2) include benzene, biphenyl, terphenyl, tetrakisphenyl, styrene, naphthalene, anthracene, acenaphthalene, fluorene, phenanthrene, indane, pyrene, triphenylene, pyridine, pyrimidine, triazine, pyrrole, furan, thiophene, quinoline, isoquinoline, benzofuran, benzothiophene, indoline, carbazole, carboline, benzoxazole, benzothiazole, quinoxaline, benzimidazole, pyrazole, dibenzofuran, dibenzothiophene, naphthyridine, phenanthroline, and acridine.

[0037] The "divalent group of a substituted or unsubstituted aromatic hydrocarbon or a substituted or unsubstituted aromatic heterocycle" represented by L in the general formulae (2-1) and (2-2) represents a divalent group obtained by removing two hydrogen atoms from the above-mentioned "aromatic hydrocarbon" or "aromatic heterocycle".

[0038] M and R in the general formulae (1), (3-1) and (3-2) ３ ~R ７The "linear or branched alkyl group having 1 to 6 carbon atoms", the "cycloalkyl group having 5 to 10 carbon atoms which may have a substituent", the "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent", the "linear or branched alkyl group having 1 to 6 carbon atoms", the "cycloalkyl group having 5 to 10 carbon atoms", the "linear or branched alkenyl group having 2 to 6 carbon atoms", the "linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent", the "cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent", or the "substituted or unsubstituted aryloxy group" are as follows: Specific examples of the "carbon or branched alkyloxy group," "cycloalkyloxy group having 5 to 10 carbon atoms," or "aryloxy group" include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a vinyl group, an allyl group, an isopropenyl group, a 2-butenyl group, a methyloxy group, an ethyloxy group, an n-propyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a 1-adamantyloxy group, a phenyloxy group, a tolyloxy group, and a biphenyloxy group.

[0039] M, L, and Ar in the general formulae (1), (2-1), (2-2), (3-1), and (3-2) １ ~Ar ３ , Q １ ~Q ３ and R ３ ~R ７Examples of the "substituent" in the "substituted aromatic hydrocarbon group", "substituted aromatic heterocyclic group", "linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent", "cycloalkyl group of 5 to 10 carbon atoms which may have a substituent", "linear or branched alkenyl group of 2 to 6 carbon atoms which may have a substituent", "linear or branched alkyloxy group of 1 to 6 carbon atoms which may have a substituent", "cycloalkyloxy group of 5 to 10 carbon atoms which may have a substituent", "substituted aryloxy group", "substituted silyl group", or "substituted boron group" include, specifically, a deuterium atom, a cyano group, a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; a silyl group such as a trimethylsilyl group or a triphenylsilyl group; a linear or branched alkyl group of 1 to 6 carbon atoms such as a methyl group, an ethyl group, or a propyl group; a linear or branched alkyloxy group of 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; alkenyl groups such as a group or an allyl group; aryloxy groups such as a phenyloxy group or a tolyloxy group; arylalkyloxy groups such as a benzyloxy group or a phenethyloxy group; aromatic hydrocarbon groups or condensed polycyclic aromatic groups such as a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a fluorenyl group, a spirobifluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, or a triphenylenyl group; pyridyl group, thienyl group, furyl group, Examples thereof include a pyrrolyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbolinyl group, and the like, as well as an aryl group having 6 to 30 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, and these substituents may be further substituted with the substituents exemplified above.Furthermore, a benzene ring substituted with these substituents or a plurality of substituents substituted on the same benzene ring may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring.

[0040] In the general formula (1), M is preferably "deuterium" or "a substituted or unsubstituted aromatic hydrocarbon group", more preferably an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, an unsubstituted terphenylyl group, or a phenyl group substituted with a terphenylyl group, and particularly preferably an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, or a phenyl group substituted with a naphthyl group.

[0041] In the general formulae (2-1) and (2-2), L is preferably a "substituted or unsubstituted divalent aromatic hydrocarbon group", more preferably a divalent group obtained by removing two hydrogen atoms from benzene, biphenyl, terphenyl, or naphthalene, and particularly preferably a divalent group obtained by removing two hydrogen atoms from benzene or biphenyl.

[0042] In the general formula (2-1), Ar １ , Ar ２ As the substituent, a "substituted or unsubstituted aromatic hydrocarbon group" is preferred, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted phenanthrenyl group, and a substituted or unsubstituted fluorenyl group are more preferred, a substituted or unsubstituted phenyl group, an unsubstituted naphthyl group, a substituted or unsubstituted biphenylyl group, and an unsubstituted phenanthrenyl group are particularly preferred, and as the substituent of the phenyl group and the biphenylyl group, a naphthyl group, a substituted or unsubstituted dibenzofuranyl group, and a carbazolyl group are preferred.

[0043] In the general formula (2-2), Ar ３As the alkyl group, a "substituted or unsubstituted aromatic hydrocarbon group" is preferred, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenylyl group, or a substituted or unsubstituted terphenylyl group is more preferred, and an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, an unsubstituted terphenylyl group, or an unsubstituted dibenzofuranyl group is particularly preferred.

[0044] In the general formulas (3-1) and (3-2), Q １ ~Q ３ As the "aromatic hydrocarbon" or "aromatic heterocycle" in the "substituted or unsubstituted aromatic hydrocarbon" or "substituted or unsubstituted aromatic heterocycle" in the above, benzene, naphthalene, phenanthrene, pyridine, pyrimidine, indene, benzofuran, benzothiophene, and indole are preferred, and benzene and naphthalene are more preferred.

[0045] In the general formulas (3-1) and (3-2), X ２ As the group, B is preferable. １ As for N-R ３ In the general formula (3-1), Y is preferably O or S, and more preferably OS. ２ and Y ３ At least one of the following is N-R ３ Preferably, both are N-R ３ It is more preferable that R ３ As the alkyl group, a "substituted or unsubstituted aromatic hydrocarbon group" is preferred, and a substituted or unsubstituted phenyl group, biphenylyl group, terphenylyl group, or naphthyl group is more preferred.

[0046] Examples of the compounds represented by the general formulas (3-1) and (3-2) include compounds having the skeletal structures shown in the following general formulas (4) to (7).

[0047]

[0048]

[0049]

[0050]

[0051] In the general formulas (4) to (7), X ２ , Y １ ~Y ３ has the same definition as in the general formulas (3-1) and (3-2), and Y ４ is N-R ３ , C-R ４ R ５ , O, S, Se or Si—R ６ R ７ represents R ３ ~R ７ has the same definition as in the general formulas (3-1) and (3-2). Z may be the same or different from each other, and CR ８ or N, and R ８ may be the same or different, and represent a hydrogen atom, a deuterium atom, a halogen group, a cyano group, a nitro group, an optionally substituted linear or branched alkyl group of 1 to 6 carbon atoms, an optionally substituted cycloalkyl group of 5 to 10 carbon atoms, an optionally substituted linear or branched alkyloxy group of 1 to 6 carbon atoms, an optionally substituted linear or branched alkylthioxy group of 1 to 6 carbon atoms, an optionally substituted linear or branched alkylamine group of 1 to 6 carbon atoms, an optionally substituted linear or branched alkylsilyl group of 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthioxy group, a substituted or unsubstituted arylamine group, or a substituted or unsubstituted arylsilyl group. ８ may be bonded to each other or to adjacent substituents to form an alicyclic or aromatic monocyclic or polycyclic ring, and the carbon atoms of the alicyclic or aromatic monocyclic or polycyclic ring may be substituted with one or more heteroatoms selected from N, S, and O.

[0052] R in the general formulas (4) to (7) ８Specific examples of the "straight-chain or branched alkyl group having 1 to 6 carbon atoms" or "cycloalkyl group having 5 to 10 carbon atoms" in the "straight-chain or branched alkyl group having 1 to 6 carbon atoms which may have a substituent" or "cycloalkyl group having 5 to 10 carbon atoms which may have a substituent" represented by the above formula include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group.

[0053] R in the general formulas (4) to (7) ８ Specific examples of the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms" in the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent" represented by the formula (1) include a methyloxy group, an ethyloxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, and an n-hexyloxy group.

[0054] R in the general formulas (4) to (7) ８ Specific examples of the "straight-chain or branched alkylthioxy group having 1 to 6 carbon atoms" in the "straight-chain or branched alkylthioxy group having 1 to 6 carbon atoms which may have a substituent" represented by the formula (1) include a methylthioxy group, an ethylthioxy group, an n-propylthioxy group, an isopropylthioxy group, an n-butylthioxy group, an isobutylthioxy group, a tert-butylthioxy group, an n-pentylthioxy group, an isopentylthioxy group, a neopentylthioxy group, and an n-hexylthioxy group.

[0055] R in the general formulas (4) to (7) ８Specific examples of the "straight-chain or branched alkylamine group having 1 to 6 carbon atoms" in the "straight-chain or branched alkylamino group having 1 to 6 carbon atoms which may have a substituent" represented by the formula (1) include a methylamine group, an ethylamine group, an n-propylamine group, an isopropylamine group, an n-butylamine group, an isobutylamine group, a tert-butylamine group, an n-pentylamine group, an isopentylamine group, a neopentylamine group, and an n-hexylamine group.

[0056] R in the general formulas (4) to (7) ８ Specific examples of the "straight-chain or branched alkylsilyl group having 3 to 10 carbon atoms" in the "straight-chain or branched alkylsilyl group having 3 to 10 carbon atoms which may have a substituent" represented by the formula (1) include a trimethylsilyl group, a triethylsilyl group, a tri-n-propylsilyl group, a triisopropylsilyl group, an n-butyldimethylsilyl group, an isobutyldimethylsilyl group, and a tert-butyldimethylsilyl group.

[0057] R in the general formulas (4) to (7) ８ Specific examples of the "aromatic hydrocarbon group" or "aromatic heterocyclic group" in the "substituted or unsubstituted aromatic hydrocarbon group" or "substituted or unsubstituted aromatic heterocyclic group" represented by the formula (I) include a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyridyl group, a pyrimidinyl group, a triazinyl group, a furyl group, a pyrrolyl group, and a thienyl group.

[0058] R in the general formulas (4) to (7) ８ Specific examples of the "aryloxy group" in the "substituted or unsubstituted aryloxy group" represented by the formula (I) include a phenyloxy group, a biphenylyloxy group, a terphenylyloxy group, a naphthyloxy group, an anthracenyloxy group, a phenanthrenyloxy group, a fluorenyloxy group, an indenyloxy group, a pyrenyloxy group, and a perylenyloxy group.

[0059] R in the general formulas (4) to (7) ８Specific examples of the "arylthioxy group" in the "substituted or unsubstituted arylthioxy group" represented by the formula (I) include a phenylthioxy group, a biphenylylthioxy group, a terphenylylthioxy group, a naphthylthioxy group, an anthracenylthioxy group, a phenanthrenylthioxy group, a fluorenylthioxy group, an indenylthioxy group, a pyrenylthioxy group, and a perylenylthioxy group.

[0060] R in the general formulas (4) to (7) ８ Specific examples of the "arylamine group" in the "substituted or unsubstituted arylamine group" represented by the formula (I) include a phenylamine group, a biphenylylamine group, a terphenylylamine group, a naphthylamine group, an anthracenylamine group, a phenanthrenylamine group, a fluorenylamine group, an indenylamine group, a pyrenylamine group, and a perylenylamine group.

[0061] R in the general formulas (4) to (7) ８ Specific examples of the "arylsilyl group" in the "substituted or unsubstituted arylsilyl group" represented by the formula (I) include a triphenylsilyl group, a trinaphthylsilyl group, and a terphenylsilyl group.

[0062] The arylamine compounds represented by the general formula (1) used in the organic EL device of the present invention have higher hole mobility than conventional hole transport materials, excellent electron blocking ability and amorphous properties, and are stable in a thin film state. Therefore, by using these as a constituent material of the hole transport layer, an organic EL device with high efficiency, low driving voltage, and long life can be realized.

[0063] Furthermore, in the present invention, the hole transport layer has a two-layer structure consisting of a first hole transport layer and a second hole transport layer, and the second hole transport layer located adjacent to the light-emitting layer is formed from the arylamine compound of general formula (1). This makes it possible to make the most of the electron blocking ability of the arylamine compound, and to realize an organic EL element with higher efficiency and longer life.

[0064] FIG. 1 is a diagram showing the structural formulas of compounds (1-1) to (1-9) as examples of arylamine compounds represented by general formula (1). FIG. 2 is a diagram showing the structural formulas of compounds (1-10) to (1-18) as examples of arylamine compounds represented by general formula (1). FIG. 3 is a diagram showing the structural formulas of compounds (1-19) to 1-27 as examples of arylamine compounds represented by general formula (1). FIG. 4 is a diagram showing the structural formulas of compounds (1-28) to (1-36) as examples of arylamine compounds represented by general formula (1). FIG. 5 is a diagram showing the structural formulas of compounds (1-37) to (1-48) as examples of arylamine compounds represented by general formula (1). FIG. 6 is a diagram showing the structural formulas of compounds (1-49) to (1-57) as examples of arylamine compounds represented by general formula (1). FIG. 7 is a diagram showing the structural formulas of compounds (1-58) to (1-69) as examples of arylamine compounds represented by general formula (1). FIG. 8 is a diagram showing the structural formulas of compounds (1-70) to (1-81) as examples of arylamine compounds represented by general formula (1). FIG. 1 is a diagram showing the structural formulas of compounds (1-82) to (1-90) as examples of arylamine compounds represented by general formula (1). FIG. 2 is a diagram showing the structural formulas of compounds (1-91) to (1-99) as examples of arylamine compounds represented by general formula (1). FIG. 3 is a diagram showing the structural formulas of compounds (1-100) to (1-108) as examples of arylamine compounds represented by general formula (1). FIG. 4 is a diagram showing the structural formulas of compounds (2-1) to (2-15) as examples of compounds represented by general formula (3-1). FIG. 5 is a diagram showing the structural formulas of compounds (2-16) to (2-24) as examples of compounds represented by general formula (3-1). FIG. 6 is a diagram showing the structural formulas of compounds (3-1) to (3-6) as examples of compounds represented by general formula (3-2). FIG. 7 is a diagram showing the configurations of organic EL devices in examples and comparative examples of the present invention.

[0065] Among the arylamine compounds represented by the general formula (1) that are suitably used in the organic EL device of the present invention, specific examples of preferred compounds are shown in FIGS. 1 to 11, but the present invention is not limited to these compounds.

[0066] Among the compounds represented by the general formula (3-1) that are suitably used in the organic EL element of the present invention, specific examples of preferred compounds are shown in FIGS. 12 and 13, but the present invention is not limited to these compounds.

[0067] Among the compounds represented by the general formula (3-2) that are suitably used in the organic EL element of the present invention, specific examples of preferred compounds are shown in FIG. 14, but the present invention is not limited to these compounds.

[0068] The arylamine compound represented by the general formula (1) can be purified by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, sublimation purification, etc. The compound can be identified by NMR analysis. It is preferable to measure the melting point, glass transition point (Tg), and work function as physical property values. The melting point is an index of vapor deposition property, the glass transition point (Tg) is an index of stability in a thin film state, and the work function is an index of hole transport property and hole blocking property. Furthermore, it is preferable to use a compound used in the organic EL device of the present invention that has been purified by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, sublimation purification, etc., and then finally purified by sublimation purification.

[0069] The melting point and glass transition point (Tg) can be measured using a powder with a high-sensitivity differential scanning calorimeter (DSC3100SA, manufactured by Bruker AXS).

[0070] The work function can be determined by forming a 100 nm thin film on an ITO substrate and using an ionization potential measuring device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.).

[0071] The organic EL device of the present invention may have a structure comprising an anode, a hole transport layer, an emitting layer, an electron transport layer, and a cathode, sequentially arranged on a substrate. It may also have a hole injection layer between the anode and the hole transport layer, a hole blocking layer between the emitting layer and the electron transport layer, or an electron injection layer between the electron transport layer and the cathode. These multilayer structures may include, for example, a layer that serves both as a hole injection layer and a hole transport layer, or a layer that serves both as an electron injection layer and an electron transport layer. It may also have a structure in which two or more organic layers having the same function are stacked, such as a two-layer hole transport layer, a two-layer emitting layer, or a two-layer electron transport layer. The organic EL device of the present invention preferably has a two-layer structure in which the hole transport layer is a first hole transport layer and a second hole transport layer. In this case, the second hole transport layer is adjacent to the emitting layer and functions as an electron blocking layer.

[0072] The anode of the organic EL element of the present invention uses an electrode material with a large work function, such as ITO or gold. The hole injection layer of the organic EL element of the present invention can use materials such as starburst triphenylamine derivatives and various triphenylamine tetramers; porphyrin compounds typified by copper phthalocyanine; acceptor heterocyclic compounds such as hexacyanoazatriphenylene; and coating-type polymer materials. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0073] Examples of hole-transporting materials that can be used for the hole-transport layer of the organic EL device of the present invention include benzidine derivatives such as N,N'-diphenyl-N,N'-di(m-tolyl)benzidine (TPD), N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine (NPD), and N,N,N',N'-tetrabiphenylylbenzidine; 1,1-bis[4-(di-4-tolylamino)phenyl]cyclohexane (TAPC); and the triphenylamine derivatives represented by the general formula (1), as well as various other triphenylamine derivatives. These materials may be formed into a film alone or may be mixed with other materials to form a single layer. They may also be laminated with other materials, or may be laminated with other materials, or may be laminated with other materials, or may be laminated with other materials. These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0074] Furthermore, in the hole injection layer or the hole transport layer, it is possible to use materials that are typically used for the layer, such as those doped with P-trisbromophenylaminehexachloroantimony, radialene derivatives (see, for example, Patent Document 7), or polymer compounds having a structure of a benzidine derivative such as TPD in their partial structure.

[0075] In the organic EL device of the present invention, the second hole transport layer adjacent to the light-emitting layer contains an arylamine compound represented by the general formula (1). Examples of hole transport materials that can be mixed with or used simultaneously with the arylamine compound represented by the general formula (1) include compounds having an electron blocking effect, such as carbazole derivatives such as 4,4',4''-tri(N-carbazolyl)triphenylamine (TCTA), 9,9-bis[4-(carbazol-9-yl)phenyl]fluorene, 1,3-bis(carbazol-9-yl)benzene (mCP), and 2,2-bis(4-carbazol-9-ylphenyl)adamantane (Ad-Cz), and compounds having a triphenylsilyl group and a triarylamine structure, typified by 9-[4-(carbazol-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene.

[0076] These materials may be formed into a film by themselves, or may be mixed with other materials to form a single layer, or may be laminated with other layers formed by themselves, other layers formed by mixing, or a layer formed by mixing and forming a layer formed by mixing. These materials can be formed into a thin film by known methods such as vapor deposition, spin coating, ink jetting, etc.

[0077] The light-emitting layer of the organic EL element of the present invention is ３ In addition to metal complexes of quinolinol derivatives such as those described above, various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, polyparaphenylenevinylene derivatives, etc. can be used. The light-emitting layer may be composed of a host material and a dopant material. Anthracene derivatives are preferably used as the host material. In addition to the light-emitting materials, heterocyclic compounds having an indole ring as a partial structure of a fused ring, heterocyclic compounds having a carbazole ring as a partial structure of a fused ring, carbazole derivatives, thiazole derivatives, benzimidazole derivatives, polydialkylfluorene derivatives, etc. can also be used. Pyrene derivatives and compounds represented by the general formula (3) or (4) are preferably used as the dopant material. Other examples include quinacridone, coumarin, rubrene, perylene, and derivatives thereof, benzopyran derivatives, indenophenanthrene derivatives, rhodamine derivatives, and aminostyryl derivatives. These may be formed as films alone, or may be mixed with other materials to form a single layer, or may be laminated with layers formed alone, layers formed as a mixture, or layers formed as a mixture with layers formed alone.

[0078] Phosphorescent emitters can also be used as light-emitting materials. Examples of phosphorescent emitters include metal complexes of iridium and platinum. Blue phosphorescent emitters such as FIrpic and FIr6 are used, and hole-injecting and transporting host materials such as 4,4'-di(N-carbazolyl)biphenyl (CBP) and carbazole derivatives such as TCTA and mCP can be used. Electron-transporting host materials such as p-bis(triphenylsilyl)benzene (UGH2) and 2,2',2''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (TPBI) can be used, allowing for the fabrication of high-performance organic EL devices.

[0079] In order to avoid concentration quenching, the phosphorescent light-emitting material is preferably doped into the host material by co-evaporation in an amount ranging from 1 to 30 weight percent based on the entire light-emitting layer.

[0080] Furthermore, it is also possible to use materials that emit delayed fluorescence, such as CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, and 4CzIPN, as light-emitting materials (see, for example, Non-Patent Document 3).

[0081] These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and ink jet printing.

[0082] For the hole-blocking layer of the organic EL device of the present invention, compounds having hole-blocking properties can be used, such as metal complexes of phenanthroline derivatives such as bathocuproine (BCP) and quinolinol derivatives such as aluminum(III) bis(2-methyl-8-quinolinato)-4-phenylphenolate (hereinafter abbreviated as BAlq), as well as various rare earth complexes, triazole derivatives, triazine derivatives, and oxadiazole derivatives. These materials may also serve as materials for the electron-transporting layer. These materials may be formed alone or mixed with other materials to form a single layer, or may form a laminate structure of layers formed alone, layers formed in a mixture, or layers formed in a mixture with layers formed alone. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0083] The electron transport layer of the organic EL element of the present invention is ３ Examples of materials that can be used include metal complexes of quinolinol derivatives such as BAlq, various metal complexes, triazole derivatives, triazine derivatives, oxadiazole derivatives, pyridine derivatives, pyrimidine derivatives, benzimidazole derivatives, thiadiazole derivatives, anthracene derivatives, carbodiimide derivatives, quinoxaline derivatives, pyridoindole derivatives, phenanthroline derivatives, and silole derivatives. These materials may be formed into films alone, or may be mixed with other materials to form a single layer, or may be laminated with other layers formed alone, other layers formed as a mixture, or layers formed as a mixture with other layers formed alone. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0084] For the electron injection layer of the organic EL element of the present invention, alkali metal salts such as lithium fluoride and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, metal complexes of quinolinol derivatives such as lithium quinolinol, metal oxides such as aluminum oxide, or metals such as ytterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), and cesium (Cs) can be used, but this can be omitted in the preferred selection of the electron transport layer and the cathode.

[0085] Furthermore, in the electron injection layer or electron transport layer, a material that is further doped with N-type metal such as cesium can be used in addition to the materials normally used in the layer.

[0086] The cathode of the organic EL device of the present invention is made of an electrode material having a low work function such as aluminum, or an alloy having an even lower work function such as a magnesium-silver alloy, a magnesium-indium alloy, or an aluminum-magnesium alloy.

[0087] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

[0088] Synthesis Example 1 Synthesis of Compound (1-1) 8.3 g of bis(biphenyl-4-yl)amine, 8.4 g of 1-(4-bromophenyl)-3-phenylnaphthalene, 4.5 g of sodium t-butoxide, 0.4 g of t-butylphosphine (50 wt % toluene solution), 0.2 g of palladium (II) acetate, and 84 ml of toluene were added to a reaction vessel purged with nitrogen. 7 g of silica gel was added to the reaction solution, which was stirred for 10 minutes. The mixture was then filtered through Celite at 80°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 11.5 g of compound (1-1) (yield: 82.0%).

[0089]

[0090] The structure of the obtained compound was identified using NMR. １ H-NMR (CDCl ３) the following 33 hydrogen signals were detected: δ (ppm) = 8.11-8.08 (2H), 8.02-7.99 (1H), 7.83-7.80 (3H), 7.67-7.57 (9H), 7.55-7.42 (10H), 7.41-7.33 (8H).

[0091] Synthesis Example 2 Synthesis of Compound (1-18) A nitrogen-purged reaction vessel was charged with 8.5 g of biphenyl-4-yl-{4'-(3-phenylnaphthalen-1-yl)-biphenyl-4-yl}amine, 4.6 g of 9-bromophenanthrene, 2.3 g of sodium t-butoxide, 0.3 g of t-butylphosphine (50 wt % toluene solution), 0.1 g of palladium (II) acetate, and 130 ml of toluene. 6 g of silica was added to the reaction mixture, which was stirred for 10 minutes. The mixture was then filtered through Celite at 80°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 4.7 g of compound (1-18) (yield: 41.0%).

[0092]

[0093] The structure of the obtained compound was identified using NMR. １ H-NMR (CDCl ３ ) the following 37 hydrogen signals were detected: δ (ppm) = 8.78-8.72 (2H), 8.13-8.11 (1H), 8.06 (1H), 7.98-7.95 (2H), 7.80-7.65 (9H), 7.61-7.37 (17H), 7.29-7.22 (5H).

[0094] Synthesis Example 3 Synthesis of Compound (1-21) A nitrogen-purged reaction vessel was charged with 6.2 g of 4,4,5,5-tetramethyl-2-{3-(3-phenylnaphthalen-1-yl)-phenyl}-[1,3,2]dioxaborolane, 6.6 g of bis(biphenyl-4-yl)-(4-bromophenyl)amine, 1.8 g of sodium bicarbonate, 0.2 g of 1,1'-bis(diphenylphosphino)ferrocenepalladium(II) dichloride, 80 ml of tetrahydrofuran, and 20 ml of water, and the mixture was stirred under reflux for 8 hours. The mixture was then extracted with ethyl acetate, the organic layer was separated, and the solvent was removed by distillation under reduced pressure. Recrystallization afforded 5.7 g of compound (1-21) (yield: 60.0%).

[0095]

[0096] The structure of the obtained compound was identified using NMR. １ H-NMR (CDCl ３ The following 37 hydrogen signals were detected at δ (ppm): δ (ppm) = 8.08 (1H), 7.99-7.96 (2H), 7.78-7.76 (4H), 7.69-7.68 (1H), 7.60-7.36 (22H), 7.33-7.29 (2H), 7.25-7.23 (5H).

[0097] Synthesis Example 4 Synthesis of Compound (1-30) 9.0 g of (4-[1,1']binaphthalenyl-3-yl-phenyl)-biphenyl-4-ylamine, 4.6 g of 4-bromobiphenyl, 2.6 g of sodium t-butoxide, 0.4 g of t-butylphosphine (50 wt % toluene solution), 0.1 g of palladium (II) acetate, and 90 ml of toluene were added to a nitrogen-purged reaction vessel and stirred under reflux for 3 hours. Thereafter, 6.0 g of silica gel was added to the reaction mixture, and after stirring for 10 minutes, the mixture was filtered through Celite at 80°C and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 5.8 g of compound (1-30) (yield: 49.2%).

[0098]

[0099] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl３ The following 35 hydrogen signals were detected at δ (ppm): δ (ppm) = 8.15 (1H), 7.99-7.94 (3H), 7.80-7.79 (1H), 7.71-7.69 (2H), 7.62-7.38 (18H), 7.33-7.29 (10H).

[0100] Synthesis Example 5 Synthesis of Compound (1-35) A nitrogen-purged reaction vessel was charged with 12.7 g of bis(biphenyl-4-yl)-{4'-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-biphenyl-4-yl}amine, 6.0 g of 3-bromo-1-phenylnaphthalene, 2.7 g of sodium bicarbonate, 0.3 g of 1,1'-bis(diphenylphosphino)ferrocenepalladium(II) dichloride, 80 ml of tetrahydrofuran, and 25 ml of water, and the mixture was heated and stirred under reflux for 8 hours. After completion of the reaction, methanol was added, and the mixture was stirred for 1 hour. After hot filtration and recrystallization, 8.7 g of compound (1-35) was obtained (yield 60.6%).

[0101]

[0102] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 37 hydrogen signals were detected: δ (ppm) = 8.12 (1H), 7.99-7.97 (1H), 7.92-7.90 (1H), 7.85-7.83 (2H), 7.77-7.76 (1H), 7.73-7.71 (2H), 7.61-7.50 (15H), 7.48-7.41 (6H), 7.34-7.30 (2H), 7.27-7.24 (6H).

[0103] Synthesis Example 6 Synthesis of Compound (1-52) To a nitrogen-purged reaction vessel were placed 5.8 g of 3-(4-chlorophenyl)-[1,2']-binaphthalenyl, 8.6 g of N,4',6'-triphenyl-[1,1':2',1"]terphenyl-4-amine, 3.2 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 90 ml of toluene, and the mixture was stirred under heating and reflux for 12 hours. Thereafter, 6.0 g of silica gel was added to the reaction solution, and the mixture was stirred for 10 minutes and then filtered through Celite at 80°C. Thereafter, the solvent was removed by distillation under reduced pressure, and the mixture was recrystallized by hot filtration, yielding 10.5 g of compound (1-52) (yield 79.8%).

[0104]

[0105] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 43 hydrogen signals were detected: δ (ppm) = 8.05 (1H), 8.01 (1H), 7.99-7.91 (5H), 7.78-7.77 (1H), 7.72-7.68 (5H), 7.62-7.60 (2H), 7.56-7.37 (7H), 7.26-7.19 (12H), 7.05-6.98 (5H), 6.81-6.75 (4H).

[0106] Synthesis Example 7 Synthesis of Compound (1-16) 9.1 g of biphenyl-4-yl-{4'-(3-phenylnaphthalen-1-yl)-biphenyl-4-yl}amine, 7.6 g of 2-bromo-9,9-diphenyl-9H-fluorene, 2.5 g of sodium t-butoxide, 0.3 g of t-butylphosphine (50 wt % toluene solution), 0.1 g of palladium (II) acetate, and 170 ml of toluene were added to a nitrogen-purged reaction vessel and stirred under reflux for 3 hours. Thereafter, 7.0 g of silica gel was added to the reaction mixture, which was stirred for 10 minutes and then filtered through Celite at 80°C. The solvent was then removed by distillation under reduced pressure, and the resulting mixture was separated by column chromatography to obtain 9.2 g of compound (1-16) (yield: 66.0%).

[0107]

[0108] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ The following 45 hydrogen signals were detected at δ (ppm): δ (ppm) = 8.08 (1H), 8.01-7.97 (2H), 7.79-7.77 (3H), 7.73-7.69 (3H), 7.66-7.32 (21H), 7.23-7.18 (15H).

[0109] Synthesis Example 8 Synthesis of Compound (1-56) 5.8 g of 3-(4-chlorophenyl)-[1,1']-binaphthalenyl, 11.5 g of (4-naphthalen-2-yl-phenyl)-phenyl-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl}amine, 70 ml of 1,4-dioxane, 21 ml of water, 0.5 g of trisdibenzyliacetonedipalladium(0), 0.5 g of tricyclohexylphosphine, and 8.1 g of tripotassium phosphate were added to a nitrogen-purged reaction vessel, and the mixture was stirred under reflux for 12 hours. After completion of the reaction, the mixture was extracted with ethyl acetate, the organic layer was separated, and the solvent was removed by distillation under reduced pressure. The mixture was then subjected to hot filtration and recrystallization to obtain 10.1 g of compound (1-56) (yield 75.1%).

[0110]

[0111] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 37 hydrogen signals were detected: δ (ppm) = 8.21 (1H), 7.95-8.02 (4H), 7.84-7.91 (6H), 7.75-7.76 (1H), 7.69-7.71 (2H), 7.62-7.65 (3H), 7.55-7.60 (3H), 7.45-7.52 (5H), 7.40-7.43 (1H), 7.27-7.33 (4H), 7.20-7.25 (6H), 7.06-7.10 (1H).

[0112] Synthesis Example 9 Synthesis of Compound (1-6) 8.5 g of (4-naphthalen-2-yl-phenyl)-{4-(3-phenyl-naphthalen-1-yl)phenyl}amine, 5.3 g of 2-(4-bromophenyl)naphthalene, 2.5 g of sodium t-butoxide, 0.6 g of t-butylphosphine (50 wt % toluene solution), 0.1 g of palladium(II) acetate, and 140 ml of toluene were added to a nitrogen-purged reaction vessel and stirred under reflux for 5 hours. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 7.5 g of compound (1-6) (yield: 62.7%).

[0113]

[0114] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 37 hydrogen signals were detected: δ (ppm) = 8.08 (1H), 8.06 (3H), 7.97 (1H), 7.91 (4H), 7.86 (2H), 7.78 (5H), 7.71 (4H), 7.57-7.43 (10H), 7.42-7.32 (7H).

[0115] Synthesis Example 10 Synthesis of Compound (1-50) In a nitrogen-substituted reaction vessel were placed 11.0 g of 4-(N-biphenyl-4-yl)-N-phenyl-amino-phenylboronic acid, 10.0 g of 3-(3-chlorophenyl)-[1,2′]binaphthalenyl, 11.6 g of tripotassium phosphate, 0.8 g of trisdibenzyliacetonedipalladium(0), 0.8 g of tricyclohexylphosphine, 100 ml of 1,4-dioxane, and H ２ 30 ml of ethyl acetate was added to the reaction mixture, and the mixture was stirred overnight under reflux. Ethyl acetate was added to the reaction mixture for extraction, and the organic layer was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent, yielding 14.0 g of compound (1-50) (yield 78.6%).

[0116]

[0117] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 35 hydrogen signals were detected: δ (ppm) = 8.16 (1H), 8.03 (1H), 8.02-7.89 (6H), 7.87 (1H), 7.74 (1H), 7.70 (1H), 7.63-7.53 (9H), 7.50 (2H), 7.43 (3H), 7.30 (3H), 7.23 (6H), 7.06 (1H).

[0118] Synthesis Example 11 Synthesis of Compound (1-77) 7.0 g of (4-[1,2']binaphthalenyl-3-yl-phenyl)-phenyl-amine, 7.3 g of 2-bromo-9,9-diphenyl-fluorene, 2.4 g of sodium t-butoxide, 0.4 g of t-butylphosphine (50 wt % toluene solution), 0.1 g of palladium (II) acetate, and 70 ml of toluene were added to a nitrogen-purged reaction vessel and stirred under reflux for 3 hours. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a monochlorobenzene / acetone mixed solvent to obtain 8.5 g of compound (1-77) (yield: 69.2%).

[0119]

[0120] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 39 hydrogen signals were detected: δ (ppm) = 8.04 (2H), 7.97 (2H), 7.83 (3H), 7.78 (1H), 7.69 (2H), 7.60 (3H), 7.54 (3H), 7.41 (1H), 7.34 (2H), 7.29-7.10 (18H), 7.08 (1H), 7.01 (1H).

[0121] Synthesis Example 12 Synthesis of Compound (1-78) 9.0 g of phenyl-{4-(6-phenyl-dibenzofuran-4-yl)phenyl}amine, 8.8 g of 3-(4-chlorophenyl)-[1,1']binaphthalenyl, 4.2 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 90 ml of toluene were added to a nitrogen-purged reaction vessel and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / n-heptane mixed solvent to obtain 9.7 g of compound (1-78) (yield: 59.8%).

[0122]

[0123] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 37 hydrogen signals were detected: δ (ppm) = 8.16 (1H), 8.02-7.91 (7H), 7.88 (2H), 7.81 (1H), 7.70 (2H), 7.67 (1H), 7.65 (1H), 7.61 (1H), 7.56 (1H), 7.52-7.42 (7H), 7.40 (1H), 7.37-7.22 (11H), 7.09 (1H).

[0124] Synthesis Example 13 Synthesis of Compound (1-81) Into a reaction vessel purged with nitrogen, 10.0 g of bis(biphenyl-4-yl)-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)phenyl}amine, 8.2 g of 3-biphenyl-3-yl-1-(4-chlorophenyl)-naphthalene, 8.1 g of tripotassium phosphate, 0.5 g of trisdibenzyliacetonedipalladium(0), 0.5 g of tricyclohexylphosphine, 100 ml of 1,4-dioxane, and H ２ 30 ml of ethyl acetate was added to the reaction mixture, and the mixture was stirred overnight under reflux. Ethyl acetate was then added to the reaction mixture for extraction, and the organic layer was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a toluene / acetone mixed solvent, yielding 7.1 g of compound (1-81) (yield: 49.6%).

[0125]

[0126] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 41 hydrogen signals were detected: δ (ppm) = 8.14 (1H), 8.00 (2H), 7.98 (1H), 7.82 (1H), 7.76 (3H), 7.69 (2H), 7.66-7.58 (10H), 7.58-7.52 (5H), 7.48 (3H), 7.44 (4H), 7.38 (1H), 7.33 (2H), 7.28 (6H).

[0127] Synthesis Example 14 Synthesis of Compound (1-82) In a nitrogen-substituted reaction vessel were placed 8.0 g of (4-naphthalen-2-yl-phenyl)-phenyl-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl}amine, 12.0 g of 4-(3-chlorophenyl)-[2,2′]binaphthalenyl, 9.3 g of tripotassium phosphate, 0.6 g of trisdibenzyliacetonedipalladium(0), 0.6 g of tricyclohexylphosphine, 80 ml of 1,4-dioxane, and H ２ 24 ml of 0 was added, and the mixture was stirred overnight under heating and reflux. Methanol was then added to the cooled system, and the precipitated solid was collected by filtration. The resulting mixture was purified by crystallization using a toluene / acetone mixed solvent, yielding 4.7 g of compound (1-82) (yield 30.7%).

[0128]

[0129] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 37 hydrogen signals were detected: δ (ppm) = 8.22 (2H), 8.01 (3H), 7.95 (2H), 7.91 (2H), 7.88 (4H), 7.82 (1H), 7.74 (1H), 7.70 (1H), 7.64 (1H), 7.61 (2H), 7.59 (2H), 7.55 (1H), 7.54-7.43 (6H), 7.31 (2H), 7.25-7.18 (6H), 7.07 (1H).

[0130] Synthesis Example 15 Synthesis of Compound (1-84) To a nitrogen-purged reaction vessel were added 6.4 g of bis(biphenyl-4-yl)amine, 5.6 g of 4-{3-(4-chlorophenyl)naphthalen-1-yl}dibenzofuran, 2.3 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 65 ml of toluene, followed by stirring overnight under heating and reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent, yielding 9.7 g of compound (1-84) (yield 88.9%).

[0131]

[0132] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 35 hydrogen signals were detected: δ (ppm) = 8.16 (1H), 8.07 (1H), 8.04 (1H), 8.01 (1H), 7.92 (1H), 7.72 (2H), 7.69 (1H), 7.60 (5H), 7.56-7.48 (6H), 7.47-7.40 (6H), 7.37 (3H), 7.31 (3H), 7.28 (2H), 7.25 (2H).

[0133] Synthesis Example 16 Synthesis of Compound (1-88) To a nitrogen-purged reaction vessel were placed 5.7 g of phenyl-[1,1';4',1"]terphenyl-4-ylamine, 6.5 g of 2-{3-(4-chlorophenyl)-naphthalen-1-yl}-dibenzofuran, 2.3 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 65 ml of toluene, and the mixture was stirred under heating and reflux for 5 hours. Thereafter, silica gel was added to the reaction liquid, and after stirring for 30 minutes, the mixture was filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent, yielding 2.2 g of compound (1-88) (yield 19.8%).

[0134]

[0135] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 35 hydrogen signals were detected: δ (ppm) = 8.12 (1H), 8.09 (1H), 7.99 (1H), 7.97 (1H), 7.92 (1H), 7.80 (1H), 7.70 (3H), 7.67 (4H), 7.64 (4H), 7.56 (2H), 7.52 (1H), 7.49 (1H), 7.44 (3H), 7.42-7.28 (5H), 7.23 (5H), 7.08 (1H).

[0136] Synthesis Example 17 Synthesis of Compound (1-95) 9.5 g of biphenyl-4-yl-{4-(3-phenyl-naphthalen-1-yl)-phenyl}-amine, 9.0 g of 9-(4'-chlorobiphenyl-2-yl)-carbazole, 3.1 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 95 ml of toluene were added to a nitrogen-purged reaction vessel and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 6.6 g of compound (1-95) (yield: 40.6%).

[0137]

[0138] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ The following 40 hydrogen signals were detected at δ (ppm): δ (ppm) = 8.07 (2H), 8.05 (1H), 7.97 (2H), 7.77 (2H), 7.73 (1H), 7.71 (1H), 7.62-7.54 (5H), 7.50 (4H), 7.42 (5H), 7.34 (2H), 7.31 (3H), 7.23 (2H), 7.10 (2H), 6.92 (4H), 6.82 (4H).

[0139] Synthesis Example 18 Synthesis of Compound (1-96) 10.0 g of phenyl-{4-(1-phenyl-naphthalen-3-yl)-phenyl}-amine, 10.5 g of 9-(4'-chlorobiphenyl-2-yl)-carbazole, 3.9 g of sodium t-butoxide, 0.4 g of t-butylphosphine (50 wt % toluene solution), 0.2 g of trisdibenzyliacetonedipalladium(0), and 100 ml of xylene were added to a nitrogen-purged reaction vessel and stirred under reflux for 3 hours. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 14.0 g of compound (1-96) (yield: 75.5%).

[0140]

[0141] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 36 hydrogen signals were detected: δ (ppm) = 8.06 (2H), 7.99 (1H), 7.94 (1H), 7.89 (1H), 7.71 (1H), 7.66 (1H), 7.63-7.48 (10H), 7.46 (1H), 7.40 (1H), 7.30 (2H), 7.23 (2H), 7.16 (2H), 7.08 (2H), 6.96 (1H), 6.85 (2H), 6.80 (4H), 6.68 (2H).

[0142] Synthesis Example 19 Synthesis of Compound (1-97) 9.5 g of biphenyl-4-yl-{4-(1-phenyl-naphthalen-3-yl)-phenyl}-amine, 9.0 g of 9-(4'-chlorobiphenyl-2-yl)-carbazole, 3.1 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 95 ml of toluene were added to a nitrogen-purged reaction vessel and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 6.4 g of compound (1-97) (yield: 39.5%).

[0143]

[0144] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ The following 40 hydrogen signals were detected at δ (ppm): δ (ppm) = 8.08 (2H), 8.01 (1H), 7.95 (1H), 7.89 (1H), 7.72 (1H), 7.67 (1H), 7.61 (1H), 7.60-7.49 (12H), 7.49-7.37 (6H), 7.31 (3H), 7.24 (1H), 7.09 (2H), 6.90 (2H), 6.86 (2H), 6.83 (2H), 6.74 (2H).

[0145] Synthesis Example 20 Synthesis of Compound (1-98) 7.0 g of phenyl-{4-(1-phenyl-naphthalen-3-yl)-phenyl}-amine, 8.0 g of 9-(4'-chlorobiphenyl-3-yl)-carbazole, 3.6 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 150 ml of toluene were placed in a nitrogen-purged reaction vessel and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 10.0 g of compound (1-98) (yield: 77.0%).

[0146]

[0147] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ ) the following 36 hydrogen signals were detected: δ (ppm) = 8.15 (2H), 8.03 (1H), 7.93 (1H), 7.89 (1H), 7.79 (1H), 7.69 (1H), 7.65 (4H), 7.57-7.45 (10H), 7.45-7.37 (4H), 7.29 (4H), 7.25-7.17 (6H), 7.07 (1H).

[0148] Synthesis Example 21 Synthesis of Compound (1-99) 9.0 g of biphenyl-4-yl-{4-(1-phenyl-naphthalen-3-yl)-phenyl}-amine, 8.5 g of 9-(4'-chlorobiphenyl-3-yl)-carbazole, 2.9 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 90 ml of toluene were added to a nitrogen-purged reaction vessel and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was separated by column chromatography to obtain 3.0 g of compound (1-99) (yield: 19.4%).

[0149]

[0150] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl ３ The following 40 hydrogen signals were detected at δ (ppm): δ (ppm) = 8.16 (2H), 8.05 (1H), 7.95 (1H), 7.90 (1H), 7.80 (1H), 7.69 (5H), 7.62-7.47 (15H), 7.47-7.38 (6H), 7.36-7.24 (8H).

[0151] Synthesis Example 22 Synthesis of Compound (1-101) 9.5 g of biphenyl-4-yl-(4'-carbazol-9-yl-biphenyl-4-yl)amine, 7.4 g of 3-(4-chlorophenyl)-1-phenyl-naphthalene, 3.8 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 170 ml of toluene were added to a nitrogen-purged reaction vessel and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by recrystallization using toluene to obtain 10.9 g of compound (1-101) (yield: 73.0%).

[0152]

[0153] The structure of the resulting white powder was identified using NMR. １ H-NMR (CDCl３ ) the following 40 hydrogen signals were detected: δ (ppm) = 8.16 (2H), 8.07 (1H), 7.96 (1H), 7.91 (1H), 7.82 (2H), 7.73 (2H), 7.70 (1H), 7.62 (6H), 7.56 (4H), 7.54-7.39 (11H), 7.31 (9H).

[0154] Synthesis Example 23 20.0 g of the following compound (2-11a), 18.4 g of the following compound (2-11b), 0.5 g of palladium(II) acetate, 18.9 g of sodium t-butoxide, 0.8 g of tri(t-butyl)phosphine, and 200 mL of toluene were placed in a reaction vessel and stirred under reflux for 24 hours. After cooling, the mixture was concentrated and purified by column chromatography to obtain 21.5 g (yield 84%) of the following compound (2-11c) as a powder.

[0155]

[0156]

[0157] The above compound (2-11c): 12.0 g, 120 ml of tert-butylbenzene were added to a reaction vessel, and 42.5 ml of n-butyllithium was added dropwise at -78 ° C., followed by stirring at 60 ° C. for 3 hours while aerating nitrogen gas. Next, 11.3 g of boron tribromide was added dropwise at -78 ° C., followed by stirring at room temperature for 1 hour, and then 5.9 g of N,N-diisopropylethylamine was added dropwise at 0 ° C., followed by stirring at 120 ° C. for 2 hours. After cooling, an aqueous sodium acetate solution was added and stirred, extracted with ethyl acetate, the organic layer was concentrated, and then purified by column chromatography to obtain 1.7 g (yield 11%) of the following compound (2-11) powder.

[0158]

[0159] The glass transition temperatures of the arylamine compounds obtained in Synthesis Examples 1 to 22 were measured using a high-sensitivity differential scanning calorimeter (DSC3100SA, manufactured by Bruker AXS).

[0160]

[0161] The arylamine compounds obtained in Synthesis Examples 1 to 22 have glass transition points of 100° C. or higher, which indicates that they are stable in the thin film state.

[0162] Using the arylamine compounds obtained in Synthesis Examples 1 to 22, vapor-deposited films having a thickness of 100 nm were formed on ITO substrates, and the work functions were measured using an ionization potential measuring device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.).

[0163]

[0164] The arylamine compounds obtained in Synthesis Examples 1 to 22 exhibit a preferable energy level compared with the work function of 5.4 eV of common hole transport materials such as NPD and TPD, and are found to have good hole transport ability.

[0165] [Example 1] An organic EL device was produced and its performance was evaluated using the arylamine compound obtained in Synthesis Example 1. As shown in Figure 15, the organic EL device was produced by depositing a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light-emitting layer 6, an electron transport layer 7, an electron injection layer 8, a cathode 9, and a capping layer 10 in this order on a glass substrate 1 on which a reflective ITO electrode had previously been formed as a transparent anode 2.

[0166] Specifically, a glass substrate 1 on which a 50 nm thick ITO film, a 100 nm thick silver alloy reflective film, and a 5 nm thick ITO film were sequentially formed as a transparent anode 2 was subjected to ultrasonic cleaning in isopropyl alcohol for 20 minutes and then dried for 10 minutes on a hot plate heated to 250°C. After that, UV ozone treatment was performed for 15 minutes, and the ITO-coated glass substrate was mounted in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, a hole injection layer 3 was formed covering the transparent anode 2 by binary deposition of an electron acceptor (Acceptor-1) of the following structural formula and a compound (HTM-1) of the following structural formula at a deposition rate ratio of Acceptor-1:HTM-1 = 3:97, to a thickness of 10 nm. On this hole injection layer 3, a first hole transport layer 4, HTM-1 of the following structural formula, was formed to a thickness of 140 nm. On this first hole transport layer 4, a second hole transport layer 5 was formed using compound (1-1) of Synthesis Example 1 to a thickness of 5 nm. On this second hole transport layer 5, a light-emitting layer 6 was formed by binary deposition of compound (2-11) of Example 23 and EMH-1 of the following structural formula at a deposition rate ratio of compound (2-11):EMH-1 = 5:95, resulting in a thickness of 20 nm. On this light-emitting layer 6, a second electron transport layer 7 was formed by binary deposition of ETM-1 of the following structural formula and ETM-2 of the following structural formula at a deposition rate ratio of compounds ETM-1:ETM-2 = 50:50, resulting in a thickness of 30 nm. On this electron transport layer 7, lithium fluoride was formed as an electron injection layer 8 to a thickness of 1 nm. On this electron injection layer 8, a magnesium-silver alloy was formed as a cathode 9 to a thickness of 12 nm. Finally, CPL-1 having the following structural formula was formed as a capping layer 10 to a thickness of 60 nm. The light-emitting characteristics of the fabricated organic EL device were measured by applying a DC voltage in the atmosphere at room temperature. The results are summarized in Table 1.

[0167]

[0168]

[0169]

[0170]

[0171]

[0172] [Examples 2 to 22] Organic EL devices were fabricated under the same conditions as in Example 1, except that compounds of Synthesis Examples 2 to 22 were used as the material for the second hole transport layer 5 instead of compound (1-1) of Synthesis Example 1. The characteristics of the fabricated organic EL devices were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a direct current voltage was applied to the fabricated organic EL devices are summarized in Table 1.

[0173] For comparison, an organic EL device was fabricated under the same conditions as in Example 1, except that HTM-2 having the following structural formula was used as the material for the second hole transport layer 5 instead of the compound (1-1) in Synthesis Example 1. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a direct current voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0174]

[0175] For comparison, an organic EL device was fabricated under the same conditions as in Example 1, except that HTM-3 having the following structural formula was used as the material for the second hole transport layer 5 instead of the compound (1-1) in Synthesis Example 1. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a direct current voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0176]

[0177] The device life was measured using the organic EL devices fabricated in Examples 1 to 22 and Comparative Examples 1 and 2, and the results are summarized in Table 1. The device life was measured when the luminance at the start of light emission (initial luminance) was 2000 cd / m ２ When driven at a constant current, the luminance was 1900 cd / m ２ The time taken for the luminance to decay to 95% (corresponding to 95% when the initial luminance was 100%) was measured.

[0178]

[0179] As shown in Table 1, the current density was 10 mA / cm ２ The luminous efficiency when a current of 100 kJ / s was passed through the organic EL elements of Examples 1 to 22 was 9.51 to 10.42 cd / A, which was higher than that of the organic EL elements of Comparative Examples 1 and 2, which was 8.25 to 8.41 cd / A. The power efficiency was also high, being 9.28 to 10.08 lm / W, which was higher than that of the organic EL elements of Comparative Examples 1 and 2, which was 7.61 to 7.67 lm / W. Furthermore, the element lifetime (95% decay) was 363 to 698 hours, which was longer than that of the organic EL elements of Comparative Examples 1 and 2.

[0180] As is clear from the above results, the arylamine compound having the specific structure represented by the general formula (1) has a higher hole mobility and an excellent electron blocking ability than arylamine compounds known as conventional hole transport materials, and therefore, it has been found that the organic EL element of the present invention can realize an organic EL element having a higher luminous efficiency and a longer lifetime than conventional organic EL elements.

[0181] The organic EL device using the arylamine compound having a specific structure of the present invention can improve the luminous efficiency and durability of the organic EL device, making it possible to expand the use of the organic EL device to, for example, home appliances and lighting.

[0182] REFERENCE SIGNS LIST 1 glass substrate 2 transparent anode 3 hole injection layer 4 first hole transport layer 5 second hole transport layer 6 light emitting layer 7 electron transport layer 8 electron injection layer 9 cathode 10 capping layer

Claims

1. A multilayer structure including, in order from the anode side, at least a first hole transport layer, a second hole transport layer, a blue light-emitting layer, and an electron transport layer between an anode and a cathode, having a layer containing a triarylamine compound represented by the following general formula (1) between the first hole transport layer and the electron transport layer, and the blue light-emitting layer containing a compound represented by the following general formula (3-1) or (3-2). An organic electroluminescence device. 【Chemical 1】 In general formula (1), R １ and R ２ may be the same or different and are groups represented by the following general formula (2-1) or (2-2), and one of them is a group represented by the following general formula (2-1). M is a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a thiol group, a hydroxy group, a substituted or unsubstituted linear or branched alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms, a substituted or unsubstituted linear or branched alkenyl group having 2 to 6 carbon atoms, a substituted or unsubstituted linear or branched alkyloxy group having 1 to 6 carbon atoms, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted silyl group, or a substituted or unsubstituted boron group. n is an integer of 0 to 4. When n is 2 or more, M may be the same as or different from each other, and adjacent Ms may be linked via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted nitrogen atom to form a ring. 【Chemical 2】 【Chemical Formula 3】 In general formulas (2-1) and (2-2), L is a linking group, representing a substituted or unsubstituted divalent aromatic hydrocarbon group, or a substituted or unsubstituted divalent aromatic heterocyclic group. m is an integer of 0 to 4. When m is 0, L represents a single bond. When m is 2 or more, L may be the same as or different from each other. Ar １ and Ar ２ may be the same or different and each represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, Ar ３ represents a substituted or unsubstituted aromatic hydrocarbon group. 【Chemical Formula 4】 【Chemical Formula 5】 In general formulas (3-1) and (3-2), Q1, Q2, and Q3 may be the same as or different from each other, representing a substituted or unsubstituted aromatic hydrocarbon, or a substituted or unsubstituted aromatic heterocyclic ring. X2 represents B, P, P=O, or P=S. Y1, Y2, and Y3 may be the same as or different from each other and represent N-R3, C-R4R5, O, S, Se, or Si-R6R7. R3, R4, R5, R6, and R7 may be the same as or different from each other and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group. Further, R4 and R5, and R6 and R7 may be bonded to each other through a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a mono-substituted amino group to form a ring. When Y1, Y2, and Y3 are N-R3, C-R4R5, or Si-R6R7, R3, R4, R5, R6, and R7 may be bonded to adjacent Q1, Q2, or Q3 through a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a mono-substituted amino group to form a ring.

2. The organic electroluminescence device according to claim 1, wherein the layer containing the triarylamine compound represented by the general formula (1) is a second hole transport layer.

3. In the general formula (1), R １ is the general formula (2-1), and R ２ is the general formula (2-2). The organic electroluminescence device according to claim 1.

4. In the general formula (1), R １ is the general formula (2-2), and R ２ is the general formula (2-1). The organic electroluminescence element according to claim 1.

5. The organic electroluminescence device according to any one of claims 1 to 4, wherein the blue light emitting layer contains a pyrene derivative having a pyrene skeleton in the molecule.

6. The organic electroluminescence device according to any one of claims 1 to 4, wherein the blue light emitting layer contains an anthracene derivative having an anthracene skeleton in the molecule.

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