organic electroluminescence element

Abstract

[Problem] The present invention addresses the problem of providing: a material for organic EL elements, said material being excellent in terms of hole injection / transport performance, electron blocking ability, and stability and durability in the form of a thin film; and an organic EL element which has high efficiency, low drive voltage and long service life and is obtained by combining the above-described material and various organic EL element materials that are excellent in terms of injection / transport performance of holes and electrons, electron blocking ability, and stability and durability in the form of a thin film, in such a manner that the respective characteristics of the materials are able to be exerted effectively. [Solution] The inventors have focused on the finding that a triarylamine compound having a specific structure is excellent in terms of hole injection / transport performance and stability and durability in the form of a thin film, and have accomplished the present invention by producing an organic EL element by selecting a specific arylamine compound as a material that constitutes a second hole transport layer.

Description

[Technical Field]

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

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

[0003] In 1987, C.W. Tang and his colleagues at 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 that can transport electrons and an organic material that can transport holes, and by injecting both charges into the phosphor layer to emit light, they achieved a brightness of 1000 cd / m at a voltage of 10 V or less. 2 Such high brightness has become possible (see, for example, Patent Documents 1 and 2).

[0004] To date, many improvements have been made to the practical application of organic EL devices, and the various roles of the laminated structure have been further subdivided, resulting in high efficiency and durability being achieved by electroluminescent devices in which an anode, a hole injection layer, a hole transport layer, an 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 that utilize light emission by 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 that uses 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 above non-patent documents, the selection of organic materials for an organic EL device has a significant impact on various properties of the device, such as efficiency and durability (see, for example, non-patent documents 1 to 3).

[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 the hole and electron charges to the light-emitting layer, making it necessary to create devices with excellent carrier balance. Furthermore, by improving hole injection and electron blocking properties (blocking electrons injected from the cathode), the probability of holes and electrons recombining can be increased, and by confining excitons generated in the light-emitting layer, high luminous efficiency can be achieved. Therefore, the role of 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 up to now (see, for example, Patent Document 1 and Patent Document 2). NPD has good hole transport ability, but its glass transition temperature (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 cm2 Although compounds with excellent mobility of 1 / Vs or more are known (see, for example, Patent Documents 1 and 2), their electron blocking properties are insufficient, so some electrons pass through the light-emitting layer, preventing improvements in luminous efficiency. For this reason, in order to further improve efficiency, materials with better electron blocking properties, more stable thin films, and higher heat resistance are needed. Furthermore, although highly durable aromatic amine derivatives have been reported (see, for example, Patent Document 3), these 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 Document 4 and Patent Document 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 and increase the yield of device production, there is a demand for devices that can recombine holes and electrons efficiently, have high luminous efficiency, low driving voltage, and have a long lifespan, 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 by combining materials that have excellent hole and electron injection and transport properties, as well as thin film stability and durability. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 8-048656 [Patent Document 2] Patent No. 3194657 [Patent Document 3] Patent No. 4943840 [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-151979 [Patent Document 5] International Publication No. 2008 / 62636 [Patent Document 6] International Publication No. 2014 / 009310 [Non-patent literature]

[0014] [Non-Patent Document 1] Proceedings of the 9th Seminar of the Japan Society of Applied Physics, pp. 55-61 (2001) [Non-patent document 2] Proceedings of the 9th Seminar of the Japan Society of Applied Physics, pp. 23-31 (2001) [Non-patent document 3] Appl.Phys.Let.,98,083302(2011) [Non-patent document 4] Proceedings of the 3rd Regular Meeting of the Organic EL Symposium, pages 13-14 (2006) Summary of the Invention [Problem to be solved by the invention]

[0015] The object of the present invention is to provide a material for organic EL devices having high efficiency and high durability, which has excellent 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 this material with various other 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 organic compound to be provided by the present invention should have include (1) good hole injection properties, (2) high hole mobility, (3) excellent electron blocking ability, (4) a stable thin film state, and (5) excellent heat resistance.The physical properties that the organic EL device 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. [Means for solving the problem]

[0017] Therefore, 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 ability, thin film stability, and durability, and therefore, when these are selected as materials for the hole transport layer, holes injected from the anode side can be efficiently transported. Furthermore, various organic EL devices were fabricated in combination with light-emitting materials having specific structures, and the device characteristics were evaluated, leading to the completion of the present invention.

[0018] That is, according to the present invention, the following organic EL device is provided.

[0019] 1) at least an anode, a first hole transport layer, and a second hole transport layer; blue 1. An organic electroluminescence device having an emitting layer, an electron transport layer, and a cathode in this order, wherein the second hole transport layer contains an arylamine compound represented by the following general formula (1):

[0020] [ka] (1)

[0021] In the general formula (1), R1 to R4 may be the same or different and represent a hydrogen atom, a deuterium atom, a carbonyl group, a cyano group, a silyl group which may have a substituent, a phosphino group which may have a substituent, a phosphine oxide group which may have a substituent, a linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms. L represents a substituted or unsubstituted divalent group of an aromatic hydrocarbon having 6 to 20 ring carbon atoms, or a single bond. R5 to R7 represent a hydrogen atom, a deuterium atom, a linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent, a halogen atom, or a cyano group.

[0022] 2) The organic EL device according to 1) above, wherein in formula (1), R1 and R2 may be the same or different and each represent a hydrogen atom, an optionally substituted silyl group, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms; R3 represents an optionally substituted silyl group, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms; and R4 represents a hydrogen atom, an optionally substituted silyl group, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms.

[0023] 3) In the formula (1), R1 and R2 may be the same or different and each represent a hydrogen atom, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, or an unsubstituted terphenylyl group, and R3 is an unsubstituted phenyl group, The organic EL element according to 1) or 2) above, characterized in that R4 is either an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, a phenyl group substituted with two phenyl groups, or a naphthyl group substituted with a phenyl group, and R4 is either an unsubstituted phenyl group, an unsubstituted naphthyl group, or a naphthyl group substituted with a phenyl group.

[0024] 4) The organic EL device according to any one of 1) to 3), characterized in that in the formula (1), R1 is any one of an unsubstituted phenyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, and an unsubstituted terphenylyl group; R2 is any one of a hydrogen atom, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, and an unsubstituted terphenylyl group; R3 is an unsubstituted phenyl group; and R4 is any one of an unsubstituted phenyl group, an unsubstituted naphthyl group, and a naphthyl group substituted with a phenyl group.

[0025] 5) The organic EL device according to 1) or 2) above, wherein in the formula (1), at least one of R1 to R4 is either a triphenylsilyl group or a phenyl group substituted with a triphenylsilyl group.

[0026] 6) The organic EL device according to any one of 1) to 5) above, wherein in the formula (1), all of R5 to R7 are hydrogen atoms.

[0027] 7) The organic EL device according to any one of 1) to 6) above, wherein in the formula (1), L is a 1,4-phenylene group.

[0028] 8) The organic EL device according to any one of 1) to 7) above, wherein the blue light-emitting layer contains, as a blue light-emitting dopant, a pyrene derivative having a pyrene skeleton in the molecule.

[0029] 9) The organic EL device according to any one of 1) to 7) above, wherein the blue light-emitting layer contains a compound represented by the following general formula (2) or (3) as a blue light-emitting dopant:

[0030] [ka] (2)

[0031] [ka] (3)

[0032] In general formula (2) and general formula (3), Q1 to Q3 may be the same or different and represent a substituted or unsubstituted aromatic hydrocarbon or a substituted or unsubstituted aromatic heterocycle. X2 represents B, P, P=O, or P=S. Y1 to Y3 may be the same or different and represent N-R8, CR9R 10 , O, S, Se or SiR 11 R 12 and R8 or R9 is any one of the following: 12 may 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, 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 alkenyl group of 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group of 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group of 5 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group. 10 , R 11 and R 12 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, provided that Y1 to Y3 are not N-R8, CR9R 10 , or SiR 11 R 12 In this case, R8 or R 12 may be bonded to the adjacent Q1 to Q3 via a linking group such as a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group to form a ring.

[0033] 10) The organic EL device according to any one of 1) to 9) above, wherein the blue light-emitting layer contains an anthracene derivative having an anthracene skeleton in the molecule.

[0034] Specific examples of the "straight-chain or branched alkyl group having 1 to 6 carbon atoms" in the "straight-chain or branched alkyl group having 1 to 6 carbon atoms which may have a substituent" represented by R1 to R7 in general formula (1) 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, and the like.

[0035] In the "substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in the general formula (1), ring formation Specific examples of the "aromatic hydrocarbon group having 6 to 25 carbon atoms" include a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a fluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, and a triphenylenyl group. Among the groups exemplified above, aromatic hydrocarbon groups having 6 to 20 ring carbon atoms can be exemplified as groups defined as "aromatic hydrocarbon groups having 6 to 20 ring carbon atoms".

[0036] Specific examples of the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in general formula (1) include 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 linear or branched alkyloxy group having 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; an alkenyl group such as a vinyl group or an allyl group; an aryloxy group such as a phenyloxy group or a tolyloxy group; an arylalkyloxy group such as a benzyloxy group or a phenethyloxy group; an aromatic group such as a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a fluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, or a triphenylenyl group. Examples of the aromatic heterocyclic group include a hydrocarbon group; an aromatic heterocyclic group such as a pyridyl group, a pyrimidinyl group, a triazinyl group, a thienyl group, a furyl group, a pyrrolyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, or a carbolinyl group; a di-substituted amino group substituted with an aromatic hydrocarbon group such as a diphenylamino group or a dinaphthylamino group; a di-substituted amino group substituted with an aromatic heterocyclic group such as a dipyridylamino group or a dithienylamino group; and a di-substituted amino group substituted with a substituent selected from an aromatic hydrocarbon group or an aromatic heterocyclic group, and these substituents may be further substituted with the substituents exemplified above.

[0037] Specific examples of the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1) include 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 linear or branched alkyl group having 1 to 6 carbon atoms such as 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, or an n-hexyl group; a linear or branched alkyloxy group having 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; an alkenyl group such as a vinyl group or an allyl group; an aryloxy group such as a phenyloxy group or a tolyloxy group; an arylalkyloxy group such as a benzyloxy group or a phenethyloxy group; a phenyl group, a biphenylyl group, a terphenylyl group, or a terphenylyl group. aromatic hydrocarbon groups such as a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a fluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, and a triphenylenyl group; a pyridyl group, a pyrimidinyl group, a triazinyl group, a thienyl group, a furyl group, a pyrrolyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a pyrazolyl ... disubstituted amino groups substituted with aromatic hydrocarbon groups such as diphenylamino and dinaphthylamino groups; disubstituted amino groups substituted with aromatic heterocyclic groups such as dipyridylamino and dithienylamino groups; and disubstituted amino groups substituted with a substituent selected from aromatic hydrocarbon groups or aromatic heterocyclic groups, and these substituents may be further substituted with the substituents exemplified above.

[0038] Specific examples of the "aromatic hydrocarbon having 6 to 20 ring carbon atoms" in the "substituted or unsubstituted aromatic hydrocarbon having 6 to 20 ring carbon atoms divalent group" represented by L in general formula (1) include benzene, biphenyl, terphenyl, naphthalene, anthracene, acenaphthalene, fluorene, phenanthrene, indane, pyrene, and triphenylene. Furthermore, in the "divalent group of a substituted or unsubstituted aromatic hydrocarbon having 6 to 20 ring carbon atoms" represented by L in general formula (1), the "divalent group of an aromatic hydrocarbon having 6 to 20 ring carbon atoms" represents a divalent group obtained by removing two hydrogen atoms from the above-mentioned "aromatic hydrocarbon having 6 to 20 ring carbon atoms."

[0039] Specific examples of the "substituent" in the "divalent aromatic hydrocarbon group having 6 to 20 ring carbon atoms and having a substituent" represented by L in general formula (1) include 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 linear or branched alkyl group having 1 to 6 carbon atoms such as 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, or an n-hexyl group; a linear or branched alkyloxy group having 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; an alkenyl group such as a vinyl group or an allyl group; an aryloxy group such as a phenyloxy group or a tolyloxy group; an arylalkyloxy group such as a benzyloxy group or a phenethyloxy group; a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthracenyl group, or a phenanthrenyl group. aromatic hydrocarbon groups such as a fluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, and a triphenylenyl group; a pyridyl group, a pyrimidinyl group, a triazinyl group, a thienyl group, a furyl group, a pyrrolyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, and a dibenzofuranyl group; Examples of the disubstituted amino group include aromatic heterocyclic groups such as dibenzothienyl groups and carbolinyl groups; disubstituted amino groups substituted with aromatic hydrocarbon groups such as diphenylamino groups and dinaphthylamino groups; disubstituted amino groups substituted with aromatic heterocyclic groups such as dipyridylamino groups and dithienylamino groups; and disubstituted amino groups substituted with a substituent selected from aromatic hydrocarbon groups or aromatic heterocyclic groups, and these substituents may be further substituted with the substituents exemplified above.

[0040] In the general formula (1), R1 is preferably a "hydrogen atom," a "silyl group which may have a substituent," or a "substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms," more preferably a "hydrogen atom," a "substituted or unsubstituted phenyl group," an "unsubstituted naphthyl group," an "unsubstituted biphenylyl group," an "unsubstituted terphenylyl group," or a "triphenylsilyl group," and even more preferably a "hydrogen atom," an "unsubstituted phenyl group," an "unsubstituted naphthyl group," or an "unsubstituted biphenylyl group." Here, the "substituent" of the "substituted phenyl group" is preferably a "phenyl group," a "biphenyl group," a "naphthyl group," or a "triphenylsilyl group." Specifically, R1 is more preferably a "hydrogen atom," an "unsubstituted phenyl group," an "unsubstituted naphthyl group," an "unsubstituted biphenylyl group," an "unsubstituted terphenylyl group," a "phenyl group substituted with a naphthyl group," a "triphenylsilyl group," or a "phenyl group substituted with a triphenylsilyl group," and even more preferably a "hydrogen atom," an "unsubstituted phenyl group," an "unsubstituted naphthyl group," or an "unsubstituted biphenylyl group."

[0041] In the general formula (1), R2 is preferably a "hydrogen atom," a "silyl group which may have a substituent," or a "substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms," more preferably a "hydrogen atom," a "substituted or unsubstituted phenyl group," an "unsubstituted naphthyl group," an "unsubstituted biphenylyl group," an "unsubstituted terphenylyl group," or a "triphenylsilyl group," and even more preferably a "hydrogen atom" or an "unsubstituted phenyl group." Here, the "substituent" of the "substituted phenyl group" is preferably a "phenyl group," a "biphenyl group," a "naphthyl group," or a "triphenylsilyl group." Specifically, R2 is more preferably a "hydrogen atom," an "unsubstituted phenyl group," an "unsubstituted naphthyl group," an "unsubstituted biphenylyl group," an "unsubstituted terphenylyl group," a "phenyl group substituted with a naphthyl group," a "triphenylsilyl group," or a "phenyl group substituted with a triphenylsilyl group," and even more preferably a "hydrogen atom" or an "unsubstituted phenyl group."

[0042] In the general formula (1), R3 is preferably a "silyl group which may have a substituent" or a "substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms", more preferably a "substituted or unsubstituted phenyl group", a "substituted or unsubstituted biphenyl group", a "substituted or unsubstituted naphthyl group", or a "triphenylsilyl group", and even more preferably a "substituted or unsubstituted phenyl group", an "unsubstituted biphenylyl group", or a "substituted naphthyl group". Here, the "substituent" in the "substituted phenyl group," "substituted biphenyl group," and "substituted naphthyl group" is preferably a "phenyl group," "naphthyl group," or "triphenylsilyl group," and more preferably a "phenyl group" or "naphthyl group." It is also preferable to have multiple (e.g., two) "phenyl groups." Specifically, R3 is more preferably an "unsubstituted phenyl group," an "unsubstituted biphenyl group," a "naphthyl group having a substituent," a "triphenylsilyl group," or a "phenyl group substituted with a triphenylsilyl group," and even more preferably an "unsubstituted phenyl group," an "unsubstituted biphenylyl group," a "phenyl group substituted with a naphthyl group," a "phenyl group substituted with two phenyl groups," or a "naphthyl group substituted with a phenyl group."

[0043] In the general formula (1), R4 is preferably a "hydrogen atom", "an optionally substituted silyl group", or "a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms", more preferably an "unsubstituted phenyl group", "a substituted or unsubstituted naphthyl group", or "a triphenylsilyl group", and even more preferably a "substituted or unsubstituted naphthyl group". Here, the "substituent" of the "substituted naphthyl group" is preferably a "phenyl group" or a "triphenylsilyl group", more preferably a "phenyl group". Specifically, R4 is more preferably an "unsubstituted phenyl group," an "unsubstituted naphthyl group," a "naphthyl group substituted with a phenyl group," a "triphenylsilyl group," or a "phenyl group substituted with a triphenylsilyl group," and even more preferably an "unsubstituted naphthyl group" or a "naphthyl group substituted with a phenyl group."

[0044] In general formula (1), it is preferable that at least one of R1 to R4 is a triphenylsilyl group or a phenyl group substituted with a triphenylsilyl group. Furthermore, R5 to R7 are preferably hydrogen atoms, and it is more preferable that all of R5 to R7 are hydrogen atoms.

[0045] In the general formula (1), L is preferably a "divalent group of a substituted or unsubstituted aromatic hydrocarbon having 6 to 20 ring carbon atoms," more preferably a divalent group obtained by removing two hydrogen atoms from benzene, biphenyl, or naphthalene, and even more preferably a 1,4-phenylene group.

[0046] Specific examples of the "aromatic hydrocarbon" or "aromatic heterocycle" in the "substituted or unsubstituted aromatic hydrocarbon" or "substituted or unsubstituted aromatic heterocycle" represented by Q1 to Q3 in general formula (2) and general formula (3) include benzene, naphthalene, anthracene, fluorene, phenanthrene, pyridine, pyrimidine, triazine, pyrrole, furan, thiophene, quinoline, isoquinoline, indene, benzofuran, benzothiophene, indole, indoline, carbazole, carboline, benzoxazole, benzothiazole, quinoxaline, benzimidazole, pyrazole, dibenzofuran, dibenzothiophene, naphthyridine, phenanthroline, and acridine.

[0047] These may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in the general formula (1). These substituents 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.

[0048] X2 in general formula (2) and general formula (3) 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 bonded to an oxygen atom by a double bond, or P=S as a phosphorus atom bonded to a sulfur atom by a double bond.

[0049] In the general formula (2) and the general formula (3), Y1 to Y3 may be the same or different from each other, and N—R8, CR9R 10 , O, S, Se or SiR 11 R 12 N-R8 is a nitrogen atom having R8 as a substituent, CR9R 10 is R9 and R 10 as a substituent, O is an oxygen atom, S is a sulfur atom, Se is a selenium atom, and SiR 11 R 12 is R 11 and R 12 is defined as a silicon atom having as a substituent. Here, R8~R 12 are adjacent Q1, Q2 or Q3, i.e., Y1 is N-R8, CR9R 10 , or SiR 11 R 12 In this case, Q1 and Y2 are N-R8 and CR9R 10 , or SiR 11 R 12 In this case, Q2 or Q3 and Y3 are N-R8, CR9R 10 , or SiR 11 R 12In the case of the above, they may be bonded to each other via a linking group such as a single bond, a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group to form a ring. Also, R9 and R 10 , R 11 and R 12 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. In addition, R8~R 12 The definition of is further explained in detail below.

[0050] In the general formula (2) and the general formula (3), Y1 to Y3 are N-R8, CR9 R 10 Ma or SiR 11 R 12 In this case, R8~R 12 Specific examples of the "straight-chain or branched alkyl group having 1 to 6 carbon atoms," "cycloalkyl group having 5 to 10 carbon atoms," or "straight-chain or branched alkenyl group having 2 to 6 carbon atoms" in the "straight-chain or branched alkyl group having 1 to 6 carbon atoms, which may have a substituent," "cycloalkyl group having 5 to 10 carbon atoms, which may have a substituent," or "straight-chain or branched alkenyl group having 2 to 6 carbon atoms," represented by the formula (I) above, 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, and a 2-butenyl group.

[0051] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0052] In the general formula (2) and the general formula (3), Y1 to Y3 are N-R8, CR9 R 10 Ma or SiR 11 R 12 In this case, R8~R 12 Specific examples of the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms" or "cycloalkyloxy group having 5 to 10 carbon atoms" in the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent" or "cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent" represented by the formula (I) 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, an n-hexyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, a cyclooctyloxy group, a 1-adamantyloxy group, and a 2-adamantyloxy group.

[0053] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0054] In the general formula (2) and the general formula (3), Y1 to Y3 are N-R8, CR9 R 10 Ma or SiR 11 R 12 In this case, R8~R 12 Specific examples of the "aromatic hydrocarbon group" and the "aromatic heterocyclic group" in the "substituted or unsubstituted aromatic hydrocarbon group" and "substituted or unsubstituted aromatic heterocyclic group" represented by the following 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.

[0055] These groups may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1).

[0056] In the general formula (2) and the general formula (3), Y1 to Y3 are N-R8, CR9 R 10 Ma or SiR 11 R 12 In this case, R8~R 12 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.

[0057] These groups may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1).

[0058] In the general formulas (2) and (3), the "aromatic hydrocarbon" or "aromatic heterocycle" in the "substituted or unsubstituted aromatic hydrocarbon" or "substituted or unsubstituted aromatic heterocycle" of Q1 to Q3 is preferably benzene, naphthalene, phenanthrene, pyridine, pyrimidine, indene, benzofuran, benzothiophene, or indole, and more preferably benzene or naphthalene.

[0059] In the general formula (2) and the general formula (3), Y1 to Y3 are N-R8, CR9R10 or SiR 11 R 12 If R8~R 12 is preferably 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, or a substituted or unsubstituted aryloxy group, and R8 is more preferably 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, or a substituted or unsubstituted aromatic hydrocarbon group.

[0060] In the general formula (2) and general formula (3), Y1 is preferably N-R8, O or S, and more preferably O or S. In general formula (2), at least one of Y2 and Y3 is preferably N-R8, and more preferably both Y2 and Y3 are N-R8. Here, R8 is preferably a "substituted or unsubstituted aromatic hydrocarbon group," and more preferably a substituted or unsubstituted phenyl group, biphenylyl group, terphenylyl group, or naphthyl group.

[0061] According to the present invention, the general formula (2) or general formula (3) can form a skeletal structure shown in the following general formula (4), general formula (5), general formula (6), or general formula (7).

[0062] [ka] (4)

[0063] [ka] (5)

[0064] [ka] (6)

[0065] [ka] (7)

[0066] In the general formulas (4) to (7), X2 and Y 1、 Y 2、 Y3 has the same definition as in the general formula (2) and the general formula (3). In the general formula (6) or (7), Y4 is N-R8, CR9R 10 , O, S, Se or SiR 11 R 12 One of the following is selected from R8 to R 12 is the same as defined in the general formula (2) and the general formula (3). In the general formulas (4) to (7), Z may be the same or different, and CR 13 or N (nitrogen atom), and each R 13may be the same or different, and represent a hydrogen atom, a deuterium atom, a halogen atom, 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 alkylamino 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 arylamino group, or a substituted or unsubstituted arylsilyl group. 13 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.

[0067] R in general formula (4) to general formula (7) 13 Specific 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.

[0068] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0069] R in general formula (4) to general formula (7) 13 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.

[0070] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0071] R in general formula (4) to general formula (7) 13 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 following formula 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, an n-hexylthioxy group, and the like.

[0072] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0073] R in general formula (4) to general formula (7) 13 Specific examples of the "linear or branched alkylamino group having 1 to 6 carbon atoms" in the "linear or branched alkylamino group having 1 to 6 carbon atoms which may have a substituent" represented by the following 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, an n-hexylamine group, and the like.

[0074] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0075] R in general formula (4) to general formula (7) 13 Specific examples of the "C 3 to C 10 linear or branched alkylsilyl group" in the "C 3 to C 10 linear or branched alkylsilyl group which may have a substituent" represented by the following 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.

[0076] These may also have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms" represented by R1 to R7 in the general formula (1).

[0077] R in general formula (4) to general formula (7) 13Specific 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.

[0078] These may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1).

[0079] R in general formula (4) to general formula (7) 13 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.

[0080] These may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1).

[0081] R in general formula (4) to general formula (7) 13Specific 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.

[0082] These may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1).

[0083] R in general formula (4) to general formula (7) 13 Specific examples of the "arylamino group" in the "substituted or unsubstituted arylamino group" represented by the formula (I) include a phenylamino group, a biphenylylamino group, a terphenylylamino group, a naphthylamino group, an anthracenylamino group, a phenanthrenylamino group, a fluorenylamino group, an indenylamino group, a pyrenylamino group, and a perylenylamino group.

[0084] These may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1).

[0085] R in general formula (4) to general formula (7) 13 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.

[0086] These may have a substituent, and examples of the substituent include the same as those shown as the "substituent" in the "substituted silyl group," "substituted phosphino group," "substituted phosphine oxide group," or "substituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms" represented by R1 to R4 in general formula (1). [Effects of the Invention]

[0087] The arylamine compound of the present invention represented by the general formula (1) has a higher hole mobility than conventional hole transport materials, has excellent electron blocking ability and amorphous properties, and is stable in a thin film state. Therefore, the organic EL device of the present invention using the arylamine compound as a constituent material of the hole transport layer can realize an organic EL device with high efficiency, low driving voltage, and long life.

[0088] 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 on the light-emitting layer side 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, thereby realizing an organic EL device with higher efficiency and longer life. [Brief explanation of the drawings]

[0089] [Figure 1] FIG. 1 shows the structural formulas of compounds (1-1) to (1-15) as examples of arylamine compounds represented by general formula (1). [Figure 2] FIG. 1 shows the structural formulas of compounds (1-16) to (1-27) as examples of arylamine compounds represented by general formula (1). [Figure 3] FIG. 1 shows the structural formulas of compounds (1-28) to (1-39) as examples of arylamine compounds represented by general formula (1). [Figure 4]FIG. 1 shows the structural formulas of compounds (1-40) to (1-51) as examples of arylamine compounds represented by general formula (1). [Figure 5] FIG. 1 shows the structural formulas of compounds (1-52) to (1-63) as examples of arylamine compounds represented by general formula (1). [Figure 6] FIG. 1 shows the structural formulas of compounds (1-64) to (1-76) as examples of arylamine compounds represented by general formula (1). [Figure 7] FIG. 1 shows the structural formulas of compounds (2-1) to (2-11) as examples of compounds represented by general formula (2). [Figure 8] FIG. 1 shows the structural formulas of compounds (2-12) to (2-26) as examples of compounds represented by general formula (2). [Figure 9] FIG. 1 shows the structural formulas of compounds (3-1) to (3-12) as examples of compounds represented by general formula (3). [Figure 10] FIG. 1 is a diagram showing the configurations of organic EL elements according to an example of the present invention and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0090] Among the arylamine compounds represented by the general formula (1) that can be suitably used in the organic EL device of the present invention, specific examples of preferred compounds are shown in Figs. 1 to 6, but the present invention is not limited to these compounds.

[0091] Among the compounds represented by the general formula (2) that are suitably used in the organic EL device of the present invention, specific examples of preferred compounds are shown in FIGS. 7 and 8, but the present invention is not limited to these compounds.

[0092] Among the compounds represented by the general formula (3) that are suitably used in the organic EL device of the present invention, specific examples of preferred compounds are shown in FIG. 9, but the present invention is not limited to these compounds.

[0093] The arylamine compounds represented by general formula (1) were purified by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using solvents, sublimation purification, etc. The compounds were identified by NMR analysis. The glass transition temperature (Tg) and work function were measured as physical properties. The glass transition temperature (Tg) is an index of the stability of the thin film state, and the work function is an index of hole transport properties and electronic In addition, the compounds used in the organic EL device of the present invention are purified by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, etc., and then finally purified by sublimation purification.

[0094] The glass transition temperature (Tg) was measured using a high-sensitivity differential scanning calorimeter (DSC3100SA, manufactured by Bruker AXS) using powder.

[0095] The work function was 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.).

[0096] The organic EL device of the present invention may have a structure comprising, in order on a substrate, an anode, a hole transport layer, an emitting layer, an electron transport layer, and a cathode; 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. In these multilayer structures, some organic layers may be omitted or may serve as both layers. For example, a layer may serve as both a hole injection layer and a hole transport layer, or a layer may serve as both an electron injection layer and an electron transport layer. Furthermore, two or more organic layers having the same function may be stacked, such as a layer with two hole transport layers, a layer with two emitting layers, or a layer with two electron transport layers. 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. stomach.In this case, the second hole transporting layer is preferably adjacent to the light emitting layer, and in this case, it can function as an electron blocking layer.

[0097] The anode of the organic EL device of the present invention is made of an electrode material having a large work function, such as ITO or gold. , an arylamine compound having only one triphenylamine structure in the molecule Materials that can be used include starburst-type triphenylamine derivatives, various triphenylamine tetramers, porphyrin compounds such as copper phthalocyanine, acceptor heterocyclic compounds such as hexacyanoazatriphenylene, and coating-type polymer materials. These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0098] 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), NPD, and N,N,N',N'-tetrabiphenylylbenzidine; 1,1-bis[4-(di-4-tolylamino)phenyl]cyclohexane (TAPC); and, in particular, arylamine compounds having two triphenylamine structures in the molecule linked by a single bond or a divalent group not containing a heteroatom, such as N,N,N',N'-tetrabiphenylylbenzidine, and arylamine compounds having only one triphenylamine structure in the molecule, such as the triphenylamine derivative represented by the general formula (1). Also useful are organic amine compounds such as various triphenylamine derivatives, including various triphenylamine trimers and tetramers, that have three or more triphenylamine structures in the molecule linked by a single bond or a divalent group not containing a heteroatom. 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.

[0099] Furthermore, in the hole injection layer or hole transport layer, materials that are typically used for the layer can be further doped with P, such as trisbromophenylaminehexachloroantimony or radialene derivatives (see, for example, Patent Document 6), or polymer compounds having a structure of a benzidine derivative such as TPD in their partial structure.

[0100] The second hole-transporting layer located on the light-emitting layer side of the organic EL device of the present invention uses an arylamine compound represented by the general formula (1). Examples of hole-transporting materials that can be mixed with or used simultaneously with the arylamine compound represented by the general formula (1) include compounds with electron blocking properties, 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, such as 9-[4-(carbazol-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene.

[0101] 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.

[0102] For the light-emitting layer of the organic EL device of the present invention, blue-emitting dopants such as pyrene derivatives having a pyrene skeleton in the molecule and compounds represented by the general formula (2) or (3) are preferably used. Other examples include metal complexes of quinolinol derivatives such as Alq3, various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, and polyparaphenylenevinylene derivatives. The light-emitting layer may also be composed of a host material and a dopant material. In this case, anthracene derivatives having an anthracene skeleton in the molecule 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 the fused ring, heterocyclic compounds having a carbazole ring as a partial structure of the fused ring, carbazole derivatives, thiazole derivatives, benzimidazole derivatives, and polydialkylfluorene derivatives can also be used. As the dopant material, a pyrene derivative having a pyrene skeleton in the molecule and a compound represented by the general formula (2) or (3) are preferably used, but other materials that can be used include 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, quinacridone, coumarin, rubrene, perylene, and derivatives thereof, benzopyran derivatives, indenophenanthrene derivatives, rhodamine derivatives, and aminostyryl derivatives. These may be formed into a film alone or may be mixed with other materials to form a single layer, or may be formed into a laminate structure of layers formed alone, layers formed as a mixture, or layers formed as a mixture with other layers.

[0103] Phosphorescent emitters can also be used as light-emitting materials. Metal complexes of iridium and platinum can be used as phosphorescent emitters. Blue phosphorescent emitters such as FIrpic and FIr6 are used, and hole-injecting and transporting host materials such as carbazole derivatives such as 4,4'-di(N-carbazolyl)biphenyl (CBP), 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.

[0104] 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.

[0105] Furthermore, materials that emit delayed fluorescence, such as CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, and 4CzIPN, can also be used as light-emitting materials (see, for example, Non-Patent Document 3).

[0106] These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and ink jet printing.

[0107] The hole-blocking layer of the organic EL device of the present invention can be formed using compounds with hole-blocking properties, such as phenanthroline derivatives such as bathocuproine (BCP) and metal complexes of quinolinol derivatives such as aluminum(III) bis(2-methyl-8-quinolinato)-4-phenylphenolate (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 be stacked together with other layers, or with other layers, or with other layers. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0108] The electron transport layer of the organic EL device of the present invention can be formed using metal complexes of quinolinol derivatives such as Alq3 and 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, silole derivatives, and the like. These materials can be formed into thin films by vapor deposition or known methods such as spin coating and inkjet printing. These materials can be used alone or mixed with other materials to form a single layer. They can also be used as a laminate structure consisting of layers formed alone, layers formed in a mixture, or layers formed in a mixture with other layers. These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0109] The electron injection layer of the organic EL device of the present invention can be made of 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). However, in the preferred selection of the electron transport layer and the cathode, this can be omitted.

[0110] Furthermore, in the electron injection layer or electron transport layer, a material that is further doped with N metal such as cesium in addition to the material normally used for the layer can be used.

[0111] 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.

[0112] For the capping layer of the organic EL device of the present invention, it is preferable to use an arylamine compound having a structure in which 2 to 6 triphenylamine structures are linked in the molecule by a single bond or a divalent group not containing a heteroatom, an amine compound having a benzoazole ring structure, or an amine compound having an aromatic heterocyclic group in the molecule. These compounds may be formed into a film alone, or may be used as a single layer formed by mixing different materials together, or may be used as a laminate structure of layers formed alone, layers formed by mixing, or layers formed by mixing layers formed alone and layers formed by mixing. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0113] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples. [Example]

[0114] Synthesis of ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-13) In a reaction vessel purged with nitrogen, 33.8 g of [1,1':2',1'']terphenyl-4'-ylamine, 30.0 g of 1-(4-bromophenyl)naphthalene, and tert- Sodium Butoxide 12.2 g of tetrahydrofuran and 300 mL of toluene were added, and the mixture was sonicated for 30 minutes while nitrogen gas was bubbled through. 1.9 g of tris(dibenzylideneacetone)dipalladium(0) and 2.6 g of 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl were added, and the mixture was heated and refluxed with stirring for 14 hours. The mixture was cooled to 80°C, and inorganic matter was removed by hot filtration. The filtrate was concentrated. The residue was recrystallized using toluene and heptane to obtain 37.0 g of a brown solid, (4-naphthalen-1-yl-phenyl)-[1,1';2',1'']terphenyl-4'-yl-amine (yield 78.1%).

[0115] 8.0 g of the obtained (4-naphthalen-1-yl-phenyl)-[1,1';2',1'']terphenyl-4'-yl-amine was added to a reaction vessel purged with nitrogen, followed by 5.0 g of 4-bromo-[1,1':4',1'']terphenyl, tert- Sodium Butoxide 2.3 g and 50 mL of toluene were added, and the mixture was subjected to ultrasonic irradiation for 30 minutes while nitrogen gas was bubbled through. 0.07 g of palladium acetate and 0.30 g of a 50% toluene solution of tri(tert-butylphosphine) were added, and the mixture was heated and refluxed with stirring for 4 hours. The mixture was cooled to 80°C, and inorganic matter was removed by hot filtration, and the filtrate was concentrated. The residue was recrystallized using toluene and acetone to obtain 13.8 g (78.8% yield) of a white solid, ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-13).

[0116] [ka] (1-13)

[0117] The structure of the resulting white solid was identified using NMR. 1 The following 37 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.03-8.06(1H), 7.82-7.90(2H), 7.58-7.69(8H), 7.42-7.53(8H), 7.13-7.27(18H). [Example]

[0118] Synthesis of ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-17) The same procedure as in Example 1 was carried out, except that 1-(4-bromophenyl)naphthalene was replaced with 2-(4-bromophenyl)naphthalene, to obtain 5.6 g (yield 57%) of a pale yellow solid, ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-17).

[0119] [ka] (1-17)

[0120] The structure of the resulting pale yellow solid was identified using NMR. 1 The following 37 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.82-8.05(3H), 7.52-7.70(8H), 7.39-7.51(8H), 7.10-7.29(18H). [Example]

[0121] <(biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-[1,1':2',1'':4'',1''':4''':1'''' ]tree Synthesis of phenyl-5'-ylamine (1-30) A reaction vessel was charged with 8.0 g of (6-bromo-biphenyl-3-yl)-(4-naphthalen-2-yl-phenyl)-biphenyl-4-ylamine, 5.7 g of 2-([1,1':4,1'']terphenyl-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 1.7 g of sodium bicarbonate, 100 mL of tetrahydrofuran, and 30 mL of water. The mixture was then sonicated for 30 minutes while nitrogen gas was passed through. 0.2 g of diphenylphosphinoferrocene palladium dichloride was added and the mixture was refluxed and stirred for 12 hours. After cooling, 200 mL of methanol was added to the reaction mixture, and the mixture was stirred for 1 hour. The precipitated solid was collected by filtration. 100 mL of toluene was added to the resulting solid, which was then heated to 80°C and purified by adsorption using silica gel and activated clay. The solid was removed by filtration, and the filtrate was concentrated. The residue was recrystallized using toluene and acetone to give (biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-[1,1':2',1'':4'',1''':4''':1'''' ]tree 8.4 g (84% yield) of a white solid of benzophenone-5'-ylamine (1-30) was obtained.

[0122] [ka] (1-30)

[0123] The structure of the resulting white solid was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.03(1H), 7.83-7.90(3H), 7.73-7.76(1H), 7.29-7.67(28H), 7.15-7.24(8H). [Example]

[0124] <(4-naphthalen-1-yl-phenyl)-(5'-phenyl-[1,1':3',1'' ]Ta Synthesis of (1,1':2',1'')terphenyl-4'-ylamine (1-32) The same procedure as in Example 1 was carried out, except that 4-bromo-[1,1':4',1'']terphenyl was replaced with 4-chloro-5'-phenyl-[1,1':3',1'']terphenyl, to obtain 3.7 g (yield 37%) of a white solid (4-naphthalen-1-yl-phenyl)-(5'-phenyl-[1,1':3',1'']terphenyl-4-yl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-32).

[0125] [ka] (1-32)

[0126] The structure of the resulting white solid was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.04-8.06(1H), 7.64-7.91(11H), 7.32-7.53(18H), 7.12-7.29(11H). [Example]

[0127] <([1,1': 4’ Synthesis of (1,1';2',1'']terphenyl-4-yl)-{4-(3-phenylnaphthalen-1-yl)phenyl}-[1,1';2',1'']terphenyl-4'-yl-amine (1-41) In Example 1, 1-(4-bromophenyl)naphthalene was replaced with 1-(4-chlorophenyl)-3-phenylnaphthalene, and the same procedure was carried out to obtain ([1,1': 4’ 5.0 g (47% yield) of a white solid of (1-41)-{4-(3-phenylnaphthalen-1-yl)phenyl}-[1,1';2',1'']terphenyl-4'-yl-amine was obtained.

[0128] [ka] (1-41)

[0129] The structure of the resulting white solid was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.04-8.05(2H), 7.94-7.96(1H), 7.76-7.78(3H), 7.59-7.67(8H), 7.43-7.52(8H), 7.12-7.22(19H). [Example]

[0130] Synthesis of (4'-naphthalen-1-yl-biphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-44) The same procedure as in Example 1 was carried out, except that 4-bromo-[1,1':4',1'']terphenyl was replaced with 1-(4'-bromo-biphenyl-4-yl)naphthalene, to obtain 4.5 g (48% yield) of a white solid, (4'-naphthalen-1-yl-biphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-44).

[0131] [ka] (1-44)

[0132] The structure of the resulting white solid was identified using NMR. 1 The following 39 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.05-8.07(1H), 7.98-8.00(1H), 7.83-7.91(4H), 7.71-7.73(2H), 7.63-7.65(2H), 7.33-7.57(19H), 7.12-7.21(10H). [Example]

[0133] Synthesis of (4-naphthalen-1-yl-phenyl)-{4-(4-phenylnaphthalen-1-yl)phenyl}-[1,1':2',1'']terphenyl-4'-yl-amine (1-58) The same procedure as in Example 1 was performed, except that 4-bromo-[1,1':4',1'']terphenyl was replaced with 1-(4-chlorophenyl)-4-phenylnaphthalene, to obtain 4.2 g (57% yield) of a white solid, (4-naphthalen-1-yl-phenyl)-{4-(4-phenylnaphthalen-1-yl)phenyl}-[1,1':2',1'']terphenyl-4'-yl-amine (1-58).

[0134] [ka] (1-58)

[0135] The structure of the resulting white solid was identified using NMR. 1 The following 39 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.12-8.14(1H), 8.05-8.07(1H), 7.96-7.98(1H), 7.89-7.91(1H), 7.83-7.85(1H), 7.32-7.55(24H), 7.14-7.23(10H). [Example]

[0136] Synthesis of ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'':4'',1'''']quaterphenyl-5'-yl-amine (1-14) A reaction vessel was charged with 12.5 g of (4-naphthalen-1-yl-phenyl)-(6-bromo-biphenyl-3-yl)amine, 6.6 g of 4-biphenylboronic acid, 3.5 g of sodium bicarbonate, 100 mL of tetrahydrofuran, and 50 mL of water. 0.5 g of diphenylphosphinoferrocene palladium dichloride was added and the mixture was refluxed and stirred for 12 hours. After cooling, the mixture was extracted with ethyl acetate, and the organic layer was concentrated. 150 mL of toluene was added to the residue and heated with stirring. 8 g of silica gel was added at 80 °C and stirred for 1 hour, and the solid was removed by hot filtration. The filtrate was concentrated, and the residue was recrystallized twice using dichloromethane and heptane to obtain 14.2 g of a white solid, (4-naphthalen-1-yl-phenyl)-[1,1':2',1:4'',1''']quaterphenyl-5'-yl-amine (yield: 97.9%).

[0137] 14.2 g of the obtained (4-naphthalen-1-yl-phenyl)-[1,1':2',1'':4'',1''']quaterphenyl-5'-yl-amine was added to a reaction vessel purged with nitrogen, followed by 9.2 g of 4-bromo-[1,1':4',1'']terphenyl, tert- Sodium Butoxide 3.9g and 140mL of toluene were added. 0.12g of palladium acetate and 0.50g of a 50% toluene solution of tri(tert-butylphosphine) were added, and the mixture was heated and stirred under reflux for 4 hours. After cooling to room temperature, 140mL of methanol was added to the reaction mixture and stirred for 1 hour. The precipitated solid was collected by filtration. 200mL of toluene was added to the solid and heated to 80°C. 10g of activated clay and 10g of silica gel were added and stirred for 1 hour. The solid was removed by hot filtration. The filtrate was concentrated, and the residue was recrystallized from toluene and acetone to obtain 16.9g (82.8% yield) of a white solid, ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'':4'',1'''']quaterphenyl-5'-yl-amine (1-14).

[0138] [ka] (1-14)

[0139] The structure of the resulting white solid was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.03-8.06(1H), 7.89-7.91(1H), 7.83-7.85(1H), 7.57-7.67(10H), 7.27-7.52(21H), 7.16-7.23(7H). [Example]

[0140] Synthesis of ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'':4'',1'''']quaterphenyl-4'-yl-amine (1-27) Into a reaction vessel purged with nitrogen, 9.2 g of (4-naphthalen-1-yl-phenyl)-[1,1':4',1'']terphenyl-3-yl-amine, 5.8 g of 4-bromo-[1,1':4',1'']terphenyl, tert- Sodium Butoxide 2.2 g and 90 mL of toluene were added. 0.1 g of tris(dibenzylideneacetone)dipalladium(0) and 0.2 g of a 50% toluene solution of tri(tert-butylphosphine) were added, and the mixture was heated and stirred at reflux for 4 hours. The mixture was cooled to 80°C, and the inorganic materials were removed by hot filtration. The filtrate was concentrated. 130 mL of toluene was added to the residue, and the mixture was heated and stirred. 6 g of silica gel and 6 g of activated clay were added at 80°C, and the mixture was stirred for 1 hour. The solid was removed by hot filtration, and the filtrate was concentrated. The residue was recrystallized using dichloromethane and acetone to obtain 11.4 g (89.8% yield) of a white solid, ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':4',1'']terphenyl-3-yl-amine.

[0141] 11.4 g of the obtained ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':4',1'']terphenyl-3-yl-amine was added to a nitrogen-purged reaction vessel, followed by 114 mL of dimethylformamide and cooling to 0°C. 3.0 g of N-bromosuccinimide was slowly added, and the mixture was stirred at 0°C for 1 hour, then slowly warmed to room temperature and stirred for 3 hours. The reaction solution was added to 360 mL of water, and the precipitated solid was collected by filtration. 130 mL of toluene was added to the solid, and the mixture was stirred and heated. 6 g of silica gel was added at 80°C, and the mixture was stirred for 1 hour. The solid was removed by hot filtration, and the filtrate was concentrated. The residue was recrystallized from dichloromethane and acetone to obtain 8.7 g (yield 69%) of a white solid of ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-(6-bromo-[1,1':4',1'']terphenyl-3-yl)amine.

[0142] 8.7 g of the obtained ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-(6-bromo-[1,1':4',1'']terphenyl-3-yl)amine was added to a nitrogen-purged reaction vessel, followed by 1.6 g of phenylboronic acid, 1.5 g of sodium bicarbonate, 100 mL of tetrahydrofuran, and 35 mL of water. 0.2 g of diphenylphosphinoferrocene palladium dichloride was added, and the mixture was refluxed and stirred for 12 hours. After cooling, the mixture was extracted with ethyl acetate, and the organic layer was concentrated. 100 mL of toluene was added to the residue, and the mixture was heated and stirred. 5 g of silica gel was added at 80°C, and the mixture was stirred for 1 hour, and the solid was removed by hot filtration. The filtrate was concentrated, and the residue was recrystallized twice using dichloromethane and acetone to obtain 6.8 g (78% yield) of a white solid of ([1,1':4',1'']terphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'':4'',1'''']quaterphenyl-4'-yl-amine (1-27).

[0143] [ka] (1-27)

[0144] The structure of the resulting white solid was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.04-8.06(1H), 7.89-7.91(1H), 7.83-7.85(1H), 7.60-7.70(8H), 7.27-7.55(23H), 7.18-7.23(7H). [Example]

[0145] Synthesis of (biphenyl-4-yl)-(4'-triphenylsilyl-biphenyl-4-yl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-62) A reaction vessel was charged with 20.0 g of 4-bromotriphenylsilane, 9.0 g of 4-chlorophenylboronic acid, 10.0 g of potassium carbonate, 160 mL of toluene, 80 mL of ethanol, and 60 mL of water. 1.1 g of tetrakistriphenylphosphine palladium was added and the mixture was refluxed and stirred for 12 hours. After cooling, the layers were separated, and the organic layer was washed with water, followed by saturated brine, and dried over anhydrous magnesium sulfate. The desiccant was removed by filtration, and the filtrate was heated and stirred, followed by addition of 10 g of silica gel at 80°C. The mixture was stirred for 1 hour, and the solid was removed by hot filtration. The filtrate was concentrated. The residue was recrystallized using toluene and heptane to obtain 12.7 g of a yellow-white solid, 4-chloro-4'-triphenylsilyl-biphenyl (yield: 59.0%).

[0146] 6.0 g of the obtained 4-chloro-4'-triphenylsilyl-biphenyl was added together with 6.6 g of (biphenyl-4-yl)-[1,1':2',1'']terphenyl-4-yl-amine to a reaction vessel purged with nitrogen, followed by tert- Sodium Butoxide2.6 g of bis[tri(tert-butylphosphine)]palladium and 60 mL of toluene were added. 0.14 g of bis[tri(tert-butylphosphine)]palladium was added, and the mixture was heated and stirred at reflux for 3 hours. After cooling to 80°C, 6 g of silica gel was added to the reaction mixture, followed by stirring for 30 minutes and hot filtration to remove the solids. The filtrate was concentrated, and the residue was purified by column chromatography (silica gel 200 g; heptane:dichloromethane=3:1) to yield 3.5 g of a white solid, (biphenyl-4-yl)-(4'-triphenylsilyl-biphenyl-4-yl)-[1,1':2',1'']terphenyl-4'-yl-amine (1-62) (30% yield).

[0147] [ka] (1-62)

[0148] The structure of the resulting white solid was identified using NMR. 1 The following 47 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.03(1H), 7.83-7.90(3H), 7.72-7.75(1H), 7.55-7.67(14H), 7.26-7.47(17H), 7.07-7.23(11H). [Example]

[0149] Synthesis of ([1,1':2',1'']terphenyl-4'-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':4',1'':4'',1'''']quaterphenyl-4-yl-amine (1-68) Into a reaction vessel purged with nitrogen, 25.0 g of (4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine, 17.4 g of 1-bromo-4-iodobenzene, tert- Sodium Butoxide7.7 g and 375 mL of toluene were added. 0.13 g of palladium acetate and 0.32 g of 4,5'-bis(diphenylphosphino)-9,9-dimethylxanthene were added, and the mixture was heated and stirred at reflux for 14 hours. The mixture was cooled to 80°C, and inorganic matter was removed by hot filtration, and the filtrate was concentrated. The residue was purified by column chromatography (silica gel 200 g; heptane:dichloromethane=3:1) to obtain 28.0 g (83.1% yield) of a yellowish-white solid, (4-bromophenyl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine.

[0150] 8.0 g of the obtained (4-bromophenyl)-(4-naphthalen-1-yl-phenyl)-[1,1':2',1'']terphenyl-4'-yl-amine was added to a reaction vessel, followed by 5.2 g of 2-([1,1':4',1'']terphenyl-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 1.7 g of sodium bicarbonate, 96 mL of tetrahydrofuran, and 32 mL of water. 0.22 g of diphenylphosphinoferrocene palladium dichloride was added and the mixture was refluxed and stirred for 4 hours. After cooling, the mixture was extracted with ethyl acetate. The organic layer was washed with water, followed by saturated brine, and dried over anhydrous magnesium sulfate. The desiccant was removed by filtration, and the filtrate was concentrated. 100 mL of toluene was added to the residue, followed by 5 g of silica gel at 80°C. After stirring for 1 hour, the solid was removed by hot filtration, and the filtrate was concentrated. The residue was recrystallized from tetrahydrofuran and acetone to give ([1,1':2',1'']terphenyl-4'-yl)-(4-naphthalen-1-yl-phenyl)-[1,1':4',1'':4'',1'''']quaterphenyl-4-yl-amine (1- 68 ) was obtained as a yellowish white solid (4.6 g, yield 46%).

[0151] [ka] (1-68)

[0152] The structure of the resulting yellow-white solid was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.04-8.06(1H), 7.83-7.91(2H), 7.60-7.73(12H), 7.43-7.52(8H), 7.13-7.38(18H). [Example]

[0153] <Synthesis of compound (2-11)> A reaction vessel was charged with 45.0 g of 1-bromobenzene (D-substituted), 58.0 g of 4-tert-butylaniline, 1.0 g of palladium (II) acetate, and tert- Sodium Butoxide 30.0 g of bis(diphenylphosphino)-1,1'-binaphthyl, 2.0 g of toluene, and 450 mL of toluene were added and stirred under reflux for 24 hours. After cooling, the mixture was concentrated and purified by column chromatography to obtain 49.9 g (78% yield) of the powder of the following compound (2-11a).

[0154] [ka] (2-11a)

[0155] A reaction vessel was charged with 20.0 g of the above compound (2-11a), 18.4 g of the following compound (2-11b), 0.5 g of palladium (II) acetate, and tert- Sodium Butoxide 18.9 g of 2-(2-methyl-2-propanol), 0.8 g of tri(tert-butyl)phosphine, and 200 mL of toluene were added 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) powder.

[0156] [ka] (2-11b)

[0157] [ka] (2-11c)

[0158] A reaction vessel was charged with 12.0 g of the compound (2-11c) and 120 mL of tert-butylbenzene, and 42.5 mL of n-butyllithium was added dropwise at -78 °C. The mixture was then stirred at 60 °C for 3 hours while nitrogen gas was passed through. Next, 11.3 g of boron tribromide was added dropwise at -78 °C, and the mixture was stirred at room temperature for 1 hour. 5.9 g of N,N-diisopropylethylamine was added dropwise at 0 °C, and the mixture was stirred at 120 °C for 2 hours. After cooling, aqueous sodium acetate was added and the mixture was stirred. The mixture was extracted with ethyl acetate, the organic layer was concentrated, and then purified by column chromatography to obtain 1.7 g of the following compound (2-11) powder (yield 11%).

[0159] [ka] (2-11) [Example]

[0160] The glass transition temperature (Tg) of the arylamine compound represented by general formula (1) was measured using a high-sensitivity differential scanning calorimeter (DSC3100SA, manufactured by Bruker AXS). The measurement results are shown below. Glass transition temperature (Tg) Compound (1-13) of Example 1 111.1°C Compound (1-17) of Example 2 109.7°C Compound (1-30) of Example 3 123.7°C Compound (1-32) of Example 4 121.0°C Compound (1-41) of Example 5 125.2°C Compound (1-44) of Example 6 118.7°C Compound (1-58) of Example 7 120.7°C Compound (1-14) of Example 8 120.4°C Compound (1-27) of Example 9 123.3°C Compound (1-62) of Example 10 124.0°C Compound (1-68) of Example 11 120.6°C

[0161] The arylamine compound represented by general formula (1) has a glass transition point (Tg) of 100° C. or higher, which indicates that the thin film state is stable. [Example]

[0162] Using the arylamine compound represented by general formula (1), a 100 nm thick film was formed by vapor deposition on an ITO substrate, and the work function was measured using an ionization potential measurement device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.). The measurement results are shown below. Work function Compound (1-13) of Example 1 5.69 eV Compound (1-17) of Example 2 5.65 eV Compound (1-30) of Example 3 5.69 eV Compound (1-32) of Example 4 5.75 eV Compound (1-41) of Example 5 5.69 eV Compound (1-44) of Example 6 5.71 eV Compound (1-58) of Example 7 5.75 eV Compound (1-14) of Example 8 5.71 eV Compound (1-27) of Example 9 5.72 eV Compound (1-62) of Example 10 5.71 eV Compound (1-68) of Example 11 5.69 eV

[0163] The arylamine compounds represented by general formula (1) exhibit a favorable energy level compared to 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 and excellent electron blocking ability. [Example]

[0164] As shown in Figure 10, the organic EL device was fabricated by depositing a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, an 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.

[0165] Specifically, a 50 nm thick ITO film, a 100 nm thick silver alloy reflective film, and a 5 nm thick ITO film were sequentially deposited on a glass substrate 1 as a transparent anode 2. The substrate was then subjected to ultrasonic cleaning in isopropyl alcohol for 20 minutes and then dried on a hot plate heated to 250°C for 10 minutes. After 15 minutes of UV ozone treatment, the ITO-attached glass substrate was placed in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Next, 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:Compound (HTM-1) = 3:97, resulting in a thickness of 10 nm. On top of this hole injection layer 3, a first hole transport layer 4 was formed of a compound (HTM-1) of the following structural formula to a thickness of 140 nm. On this first hole transport layer 4, a second hole transport layer 5 was formed using compound (1-13) of Example 1 to a thickness of 5 nm. On this second hole transport layer 5, a light-emitting layer 6 was formed using compound (2-11) of Example 12 and compound (EMH-1) of the following structural formula by binary deposition at a deposition rate ratio of compound (2-11):compound (EMH-1) = 5:95 to a thickness of 20 nm. On this light-emitting layer 6, a compound (ETM-1) of the following structural formula by binary deposition at a deposition rate ratio of compound (ETM-1):compound (ETM-2) = 50:50 to 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, a compound (CPL-1) having the following structural formula was formed to a thickness of 60 nm as a capping layer 10. 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.

[0166] [ka] (Acceptor-1)

[0167] [ka] (HTM-1)

[0168] [ka] (1-13)

[0169] [ka] (2-11)

[0170] [ka] (EMH-1)

[0171] [ka] (ETM-1)

[0172] [ka] (ETM-2)

[0173] [ka] (CPL-1) [Example]

[0174] An organic EL device was fabricated under the same conditions as in Example 15, except that compound (1-17) of Example 2 was used instead of compound (1-13) of Example 1 as the material for the second hole transport layer 5. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0175] [ka] (1-17) [Example]

[0176] An organic EL device was fabricated under the same conditions as in Example 15, except that compound (1-30) of Example 3 was used instead of compound (1-13) of Example 1 as the material for the second hole transport layer 5. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0177] [ka] (1-30) [Example]

[0178] An organic EL device was fabricated under the same conditions as in Example 15, except that compound (1-32) of Example 4 was used instead of compound (1-13) of Example 1 as the material for the second hole transport layer 5. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0179] [ka] (1-32) [Example]

[0180] An organic EL device was fabricated under the same conditions as in Example 15, except that compound (1-41) of Example 5 was used instead of compound (1-13) of Example 1 as the material for the second hole transport layer 5. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0181] [ka] (1-41) [Example]

[0182] An organic EL device was fabricated under the same conditions as in Example 15, except that compound (1-44) of Example 6 was used instead of compound (1-13) of Example 1 as the material for the second hole transport layer 5. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0183] [ka] (1-44) [Example]

[0184] An organic EL device was fabricated under the same conditions as in Example 15, except that compound (1-58) of Example 7 was used instead of compound (1-13) of Example 1 as the material for the second hole transport layer 5. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0185] [ka] (1-58) [Example]

[0186] In Example 15, the compound (1-13) in Example 1 was used as the material for the second hole transport layer 5. 8 An organic EL device was fabricated under the same conditions, except that compound (1-14) was used. The characteristics of the fabricated organic EL device were measured in air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0187] [ka] (1-14) [Example]

[0188] In Example 15, the compound (1-13) in Example 1 was used as the material for the second hole transport layer 5. 9 An organic EL device was fabricated under the same conditions, except that compound (1-27) was used. The characteristics of the fabricated organic EL device were measured in air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0189] [ka] (1-27) [Example]

[0190] In Example 15, the compound (1-13) in Example 1 was used as the material for the second hole transport layer 5. 10 An organic EL device was fabricated under the same conditions, except that compound (1-62) was used. The characteristics of the fabricated organic EL device were measured in air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0191] [ka] (1-62) [Example]

[0192] In Example 15, the compound (1-13) in Example 1 was used as the material for the second hole transport layer 5. 11 An organic EL device was fabricated under the same conditions, except that compound (1-68) was used. The characteristics of the fabricated organic EL device were measured in air at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0193] [ka] (1-68)

[0194] [Comparative Example 1] For comparison, an organic EL device was fabricated under the same conditions as in Example 15, except that the compound (HTM-2) of the following structural formula was used as the material for the second hole transport layer 5 instead of the compound (1-13) in 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 DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0195] [ka] (HTM-2)

[0196] Comparative Example 2 For comparison, an organic EL device was fabricated under the same conditions as in Example 15, except that the compound (HTM-3) of the following structural formula was used as the material for the second hole transport layer 5 instead of the compound (1-13) in 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 DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0197] [ka] (HTM-3)

[0198] Comparative Example 3 For comparison, an organic EL device was fabricated under the same conditions as in Example 15, except that the compound (HTM-4) of the following structural formula was used as the material for the second hole transport layer 5 instead of the compound (1-13) in 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 DC voltage was applied to the fabricated organic EL device are summarized in Table 1.

[0199] [ka] (HTM-4)

[0200] The device life was measured using the organic EL devices fabricated in Examples 15 to 25 and Comparative Examples 1 to 3. The results are summarized in Table 1. The device life was measured when the emission 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 it took for the brightness to decay to 95% (corresponding to 95% of the initial brightness of 100%) was measured.

[0201] [Table 1]

[0202] As shown in Table 1, the current density was 10 mA / cm 2The luminous efficiency when a current of 100 kJ / s was passed was 7.94 to 9.34 cd / A for the organic EL elements of Comparative Examples 1 to 3, while it was 9.68 to 10.75 cd / A for the organic EL elements of Examples 15 to 25, which was a high efficiency. Furthermore, the power efficiency was also high, 8.94 to 9.78 lm / W for the organic EL elements of Examples 15 to 25, while it was 7.30 to 8.61 lm / W for the organic EL elements of Comparative Examples 1 to 3. Furthermore, it can be seen that the element lifetime (95% decay) was 345 to 627 hours for the organic EL elements of Examples 15 to 25, which was significantly longer than the organic EL elements of Comparative Examples 1 to 3, which was 306 to 335 hours.

[0203] As is clear from the above results, the arylamine compound having a specific structure represented by general formula (1) according to the present invention has a higher hole mobility and an excellent electron blocking ability than the arylamine compounds used as conventional hole transport materials. Therefore, it was found that an organic EL device using the arylamine compound together with the blue light-emitting layer of the present invention can realize an organic EL device with higher luminous efficiency and longer lifetime than conventional organic EL devices. [Industrial Applicability]

[0204] 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. [Explanation of symbols]

[0205] 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. 1. An organic electroluminescence device comprising, in this order, at least an anode, a hole injection layer formed by P-doping a radialene derivative onto an arylamine compound having only one triphenylamine structure in the molecule, a first hole transport layer formed from an arylamine compound having only one triphenylamine structure in the molecule, a second hole transport layer, a blue-light-emitting layer, an electron transport layer, and a cathode, wherein the second hole transport layer contains an arylamine compound represented by the following general formula (1): 【Chemistry 1】 （１） (In the formula, R １ R to R3 may be the same or different and represent a hydrogen atom, a deuterium atom, a carbonyl group, a cyano group, an optionally substituted silyl group, an optionally substituted phosphino group, an optionally substituted phosphine oxide group, a optionally substituted linear or branched alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms; R4 represents an optionally substituted silyl group, a phenyl group substituted with an optionally substituted silyl group, or a substituted or unsubstituted naphthyl group; L represents a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzene, or a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted biphenyl; R ５ ~R ７ represents a hydrogen atom, a deuterium atom, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a halogen atom, or a cyano group.

2. In the general formula (1), R １ , R ２ may be the same or different and are a hydrogen atom, an optionally substituted silyl group, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms; R ３ is an optionally substituted silyl group or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 ring carbon atoms, R ４ 2. The organic electroluminescence device according to claim 1, wherein is a silyl group which may have a substituent, a phenyl group substituted with a silyl group which may have a substituent, or a substituted or unsubstituted naphthyl group.

3. In the general formula (1), R １ , R ２ may be the same or different and are any of a hydrogen atom, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, and an unsubstituted terphenylyl group; R ３ is an unsubstituted phenyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, a phenyl group substituted with two phenyl groups, or a naphthyl group substituted with a phenyl group; R ４ 3. The organic electroluminescent device according to claim 1, wherein is either an unsubstituted naphthyl group or a naphthyl group substituted with a phenyl group.

4. In the general formula (1), R １ is an unsubstituted phenyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, or an unsubstituted terphenylyl group, and R ２ is a hydrogen atom, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted biphenylyl group, a phenyl group substituted with a naphthyl group, or an unsubstituted terphenylyl group, and R ３ is an unsubstituted phenyl group, and R ４ 4. The organic electroluminescence device according to claim 1, wherein is either an unsubstituted naphthyl group or a naphthyl group substituted with a phenyl group.

5. In the general formula (1), R １ ~R ４ 3. The organic electroluminescence device according to claim 1, wherein at least one of the groups is a triphenylsilyl group or a phenyl group substituted with a triphenylsilyl group.

6. In the general formula (1), R ５ ~R ７ 6. The organic electroluminescence device according to claim 1, wherein all of are hydrogen atoms.

7. 7. The organic electroluminescence device according to claim 1, wherein in the general formula (1), L is a 1,4-phenylene group.

8. 8. The organic electroluminescence device according to claim 1, wherein the blue light-emitting layer contains, as a blue light-emitting dopant, a pyrene derivative having a pyrene skeleton in the molecule.

9. The organic electroluminescence element according to any one of claims 1 to 7, wherein the blue light-emitting layer contains a compound represented by the following general formula (2) or (3) as a blue light-emitting dopant: 【Chemistry 2】 （２） 【Transformation 3】 （３） (In the general formula (2) and the general formula (3), Q １ Or 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 Or Y ３ may be the same or different, and N-R ８ , C.R. ９ R １０ , O, S, Se or SiR １１ R １２ and R ８ Or R １２ may 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, 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 alkenyl group of 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group of 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group of 5 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group. ９ and R １０ , R １１ and R １２ 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. １ Or Y ３ N-R ８ , C.R. ９ R １０ , or SiR １１ R １２ In the case of ８ Or R １２ are the adjacent Q １ 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.

10. 10. The organic electroluminescence device according to claim 1, wherein the blue light-emitting layer contains an anthracene derivative having an anthracene skeleton in the molecule.

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