Arylamine compound and electronic device using the same

Abstract

The purpose of the present invention is: to provide an organic compound that is for use as a material for a highly efficient and durable organic EL element, that has excellent hole injection / transport performance, that has an electron-blocking ability, and that has high stability and excellent properties in a thin-film state; and to further provide a highly efficient and durable organic EL element using said compound.　This arylamine compound has a fluorenyl skeleton-containing heterocyclic structure, and has excellent heat resistance and good hole transporting ability. An organic EL element which uses said compound in a hole transport layer, an electron-blocking layer, a light emitting layer of the organic EL element, and a hole injection layer exhibits good element characteristics.

Description

Technical Field

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

Background Art

[0002] Since the organic EL element is a self-luminous element, it has been actively studied because it is brighter and has better visibility than a liquid crystal element and can provide a clear display.

[0003] In 1987, C.W. Tang et al. of Eastman Kodak developed a laminated structure element in which various roles were assigned to each material, making the organic EL element using an organic material practical. They laminated a phosphor capable of transporting electrons and an organic substance capable of transporting holes, and injected both charges into the phosphor layer to emit light, thereby obtaining a high luminance of 1000 cd / m 2 or more at a voltage of 10 V or less (see, for example, Patent Document 1 and Patent Document 2).

[0004] To date, many improvements have been made for the practical application of organic EL elements. The various roles of the laminated structure have been further subdivided, and a field emission element having an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode sequentially provided on a substrate has been developed to achieve high efficiency and durability (see, for example, Non-Patent Document 1).

[0005] In addition, the use of triplet excitons has been attempted for further improvement of the luminous efficiency, and the use of phosphorescent compounds has been studied (see, for example, Non-Patent Document 2). Furthermore, an element using light emission by thermally activated delayed fluorescence (TADF) has also been developed. In 2011, Adachi et al. of Kyushu University realized an external quantum efficiency of 5.3% with an element using a thermally activated delayed fluorescence material (see, for example, Non-Patent Document 3).

[0006] The light-emitting layer can generally be produced by doping a charge-transporting compound generally referred to as a host material with a fluorescent compound, a phosphorescent compound, or a material that emits delayed fluorescence. As described in the non-patent literature, the selection of organic materials in an organic EL element greatly affects various properties such as the efficiency and durability of the element (see, for example, Non-Patent Document 2).

[0007] In an organic EL element, light emission is obtained when charges injected from both electrodes recombine in the light-emitting layer. However, it is important how efficiently both charges, holes and electrons, are transferred to the light-emitting layer, and it is necessary to make an element with excellent carrier balance. Therefore, by using a material having properties that enhance the hole injection property for supplying holes injected from the anode to the light-emitting layer and enhance the electron blocking property for blocking electrons injected from the cathode, the probability of recombination of holes and electrons in the light-emitting layer can be improved, and furthermore, high luminous efficiency can be obtained by confining excitons generated in the light-emitting layer. For this purpose, the role played by the hole transport material is important, and a hole transport material with high hole injection property, high hole mobility, high electron blocking property, and furthermore high durability against electrons is required.

[0008] Regarding the lifetime of the element, the heat resistance and amorphousness of the material are also important. In a material with low heat resistance, thermal decomposition occurs even at a low temperature due to the heat generated during element driving, and the material deteriorates. In a material with low amorphousness, crystallization of the thin film occurs even in a short time, and the element deteriorates. Therefore, the material to be used is required to have high heat resistance and good amorphousness.

[0009] Hitherto, hole transport materials used in organic EL elements include N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine (NPD) and various aromatic amine derivatives (see, for example, Patent Document 1 and Patent Document 2). However, although NPD has good hole transport ability, its glass transition point (Tg) serving as an index of heat resistance is as low as 96°C, and the element characteristics deteriorate due to crystallization under high-temperature conditions (see, for example, Non-Patent Document 4).

[0010] In addition, among the aromatic amine derivatives described in the above patent documents, there are compounds having an excellent hole mobility of 10 -3 cm 2 / Vs or more (see, for example, Patent Document 1 and Patent Document 2). However, since the electron blocking property is insufficient, some electrons pass through the light-emitting layer, and it is not possible to expect an improvement in the light-emitting efficiency. Therefore, for further high efficiency, materials with higher electron blocking properties, more stable thin films, and higher heat resistance have been demanded. In addition, there are reports of highly durable aromatic amine derivatives (see, for example, Patent Document 3), which are used as charge transport materials for electrophotographic photoreceptors and have not been used as organic EL elements.

[0011] To solve this problem, arylamine compounds having a substituted carbazole structure or a heterocyclic structure containing a fluorenyl skeleton 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 the elements using these compounds in the hole injection layer or the hole transport layer, although improvements such as heat resistance and light-emitting efficiency have been made, they are not yet sufficient, and further reduction in driving voltage and increase in light-emitting efficiency are demanded.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Non-Patent Documents

[0013]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Summary of the Invention

[0014] An object of the present invention is to provide a material for an organic EL element with high efficiency and high durability, which (1) has excellent hole injection and transport performance, (2) has an electron blocking ability, (3) has high stability in a thin film state, and (4) has excellent durability.

[0015] By using the material of the present invention, an organic EL element is provided which (1) has high luminous efficiency and power efficiency, (2) has a low light emission start voltage and a practical driving voltage, and (3) has a long life.

[0016] In order to achieve the above object, the present inventors focused on the fact that an arylamine compound having a fluorenyl skeleton-containing heterocyclic structure is excellent in hole injection and transport ability, thin film stability and durability. Conventionally, an arylamine compound in which a nitrogen atom is directly bonded to the same heterocyclic group has been developed as a hole transport material. However, by providing an arylene group between the heterocyclic group and the nitrogen atom, it has become possible to develop a material with a wide energy gap and a material with high heat resistance, and the material characteristics have been dramatically improved. Also in the organic EL element, by widening the energy gap, electrons from the cathode side are blocked to suppress electron outflow, and by confining them in the light emitting layer, it contributed to the improvement of the luminous efficiency and power efficiency performance. In addition, the improvement of the luminous efficiency suppressed the power consumption, made it possible to reduce the load in the element, and the improvement of the heat resistance of the material improved the stability of the thin film, resulting in a longer life exceeding the conventional life. As a result, the present invention has been completed (see Patent Document 5).

[0017] 1) That is, the present invention is an arylamine compound having a fluorenyl skeleton-containing heterocyclic structure represented by the following general formula (A).

[0018]

Chemical formula

[0019] In the above formula, R1 to R 11 may be the same or different from each other, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. L represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group. n is 1 or 2, and when n is 2, L may be the same or different from each other. Ar1 and Ar2 may be the same or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group. X represents an oxygen atom, a sulfur atom, or a nitrogen atom having a substituent. In addition, L and Ar1, and Ar1 and Ar2 may be bonded to each other via a linking group selected from a single bond, or a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, and a nitrogen atom having a substituent between the respective groups to form a ring.

[0020] 2) Further, in the present invention, in the general formula (A), R 10and R 11 The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to 1) above, wherein 11 is a substituted or unsubstituted methyl group or a substituted or unsubstituted phenyl group.

[0021] 3) Further, the present invention provides, in the general formula (A), The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to 1) or 2) above, wherein X is an oxygen atom.

[0022] 4) Further, the present invention provides, in the general formula (A), The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to any one of 1) to 3) above, wherein L is a divalent group of a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, or a substituted or unsubstituted naphthylene group.

[0023] 5) Further, the present invention provides, in the general formula (A), The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to any one of 1) to 4) above, wherein n is 1.

[0024] 6) In an organic EL element having a pair of electrodes and at least one organic layer sandwiched therebetween, the organic EL element, wherein the organic layer contains an arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to any one of 1) to 5) above.

[0025] 7) Further, the present invention provides the organic EL element according to 6) above, wherein the organic layer is an electron blocking layer.

[0026] 8) Further, the present invention provides the organic EL element according to 6) above, wherein the organic layer is a hole transport layer.

[0027] 9) Further, the present invention provides the organic EL element according to 6) above, wherein the organic layer is a hole injection layer.

[0028] 10) The present invention also relates to the organic EL element according to 6) above, wherein the organic layer is a light-emitting layer.

[0029] 11) The present invention also relates to an electronic device using an electronic component having a pair of electrodes and at least one organic layer sandwiched therebetween, wherein the organic layer contains an arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to any one of 1) to 5) above.

[0030] R1 to R in the general formula (A) 11 Examples of the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by the 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, a 2-adamantyl group, a vinyl group, an allyl group, an isopropenyl group, and a 2-butenyl group.

[0031] R1 to R in the general formula (A) 11The "substituent" in the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by the following may specifically be a deuterium atom, a cyano group, a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom; a silyl group such as a trimethylsilyl group, a triphenylsilyl group; a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group; a linear or branched alkyloxy group having 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, a propyloxy group; an alkenyl group such as a vinyl group, an allyl group; an aryloxy group such as a phenyloxy group, a tolyloxy group; an arylalkyloxy group such as a benzyloxy group, a phenethyloxy group; an aromatic hydrocarbon group or a condensed polycyclic 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, a spirobifluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, a triphenylenyl group; an aromatic heterocyclic group such as a pyridyl 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, a carbolinyl group, and these substituents may further be substituted with the substituents exemplified above. Further, the benzene ring substituted with these substituents, or the substituents substituted on the same benzene ring and a plurality of them may be bonded to each other via a linking group selected from a single bond, or a substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, and a nitrogen atom having a substituent to form a ring.

[0032] R1 to R in general formula (A) 11The "linear 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 includes, specifically, 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, a 2-adamantyloxy group, and the like.

[0033] R1 to R in general formula (A) 11 The "substituent" in the "linear 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 is the same as those shown as the "substituent" in the "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 "alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by R1 to R in general formula (A), and the possible embodiments are also the same. 11 The "substituent" in the "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 "alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by includes the same as those shown, and the possible embodiments are also the same.

[0034] R1 to R in general formula (A) 11The "aryl group", "aromatic heterocyclic group" or "condensed polycyclic aromatic group" in the "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group" or "substituted or unsubstituted condensed polycyclic aromatic group" represented by include, specifically, phenyl group, biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthrenyl group, fluorenyl group, spirobifluorenyl group, indenyl group, pyrenyl group, perylenyl group, fluoranthenyl group, triphenylenyl group, pyridyl group, pyrimidinyl group, triazinyl group, furyl group, pyrrolyl group, thienyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, azafluorenyl group, diazafluorenyl group, azaspirobifluorenyl group, diazaspirobifluorenyl group, quinoxalinyl group, benzimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, naphthyridinyl group, phenanthrolinyl group, acridinyl group, and carbolinyl group. In addition, an aryl group having 6 to 30 carbon atoms, or a heteroaryl group having 2 to 20 carbon atoms, etc. can be mentioned.

[0035] R1 to R in general formula (A) 11 The "substituent" in the "substituted aromatic hydrocarbon group", "substituted aromatic heterocyclic group" or "substituted condensed polycyclic aromatic group" represented by is the same as those shown as the "substituent" in the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by . The possible embodiments can also be the same as those mentioned. 11 The "substituent" in the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by can include the same as those shown, and the possible aspects can also include the same as those mentioned.

[0036] R1 to R in general formula (A) 11In the "substituted or unsubstituted aryloxy group" represented by, specific examples of the "aryloxy group" include a phenyloxy group, a biphenylyloxy group, a terphenylyloxy group, a naphthyloxy group, an anthracenyloxy group, a phenanthrenyloxy group, a fluorenyloxy group, an indenyl oxy group, a pyrenyloxy group, a perylenyl oxy group, and the like.

[0037] R1 to R in the general formula (A) 11 In the "substituted aryloxy group" represented by, the "substituent" is the same as those shown as the "substituent" in the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent", and the possible embodiments are also the same. 11 10

[0038] From the viewpoint of stability in the thin film state, R1 to R9 in the general formula (A) are preferably a hydrogen atom, a deuterium atom, or a substituted or unsubstituted phenyl group, more preferably a hydrogen atom, a deuterium atom or an unsubstituted phenyl group.

[0039] R in the general formula (A) 10 and R 11 From the viewpoint of the heat resistance of the compound, a substituted or unsubstituted methyl group or a substituted or unsubstituted phenyl group is preferable, and an unsubstituted methyl group or an unsubstituted phenyl group is more preferable. Further, R 10 and R 11 are preferably the same.

[0040] In the "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group" or "substituted or unsubstituted condensed polycyclic aromatic group" represented by L in the general formula (A), the "aromatic hydrocarbon group", "aromatic heterocyclic group" or "condensed polycyclic aromatic group" is R1 to R in the general formula (A) 11Examples of the group obtained by removing one hydrogen atom from the same groups as those shown as the "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group", or "substituted or unsubstituted condensed polycyclic aromatic group" represented by can be given.

[0041] Examples of the "substituent" in the "substituted aromatic hydrocarbon group", "substituted aromatic heterocyclic group", or "substituted condensed polycyclic aromatic group" represented by L in the general formula (A) include R1 to R in the general formula (A). 11 Examples of the "substituent" in the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by are the same as those shown as the "substituent", and possible embodiments are also the same.

[0042] From the viewpoints of hole transport property and electron blocking ability, L in the general formula (A) is preferably a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, or a substituted or unsubstituted naphthylene group, more preferably an unsubstituted phenylene group, an unsubstituted biphenylene group, or an unsubstituted naphthylene group, and particularly preferably an unsubstituted phenylene group or an unsubstituted naphthylene group. Also, n in the general formula (A) is preferably 1.

[0043] Examples of the "aromatic hydrocarbon group", "aromatic heterocyclic group", or "condensed polycyclic aromatic group" in the "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group", or "substituted or unsubstituted condensed polycyclic aromatic group" represented by Ar1 and Ar2 in the general formula (A) include R1 to R in the general formula (A). 11Examples of the "aryl hydrocarbon group", "aromatic heterocyclic group" or "condensed polycyclic aromatic group" in the "substituted or unsubstituted aryl hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group" or "substituted or unsubstituted condensed polycyclic aromatic group" represented by can be the same as those shown.

[0044] Examples of the "substituent" in the "substituted aryl hydrocarbon group", "substituted aromatic heterocyclic group" or "substituted condensed polycyclic aromatic group" represented by Ar1 and Ar2 in the general formula (A) include R1 to R in the general formula (A). 11 Examples of the "substituent" in the "linear 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 "linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent" represented by can be the same as those shown, and possible embodiments can also be the same as those shown.

[0045] From the viewpoints of hole transport property and electron blocking ability, Ar1 and Ar2 in the general formula (A) are preferably an unsubstituted phenyl group or an unsubstituted biphenylyl group.

[0046] From the viewpoints of hole transport property and electron blocking ability, X in the general formula (A) is preferably an oxygen atom.

[0047] The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure represented by the general formula (A), which is preferably used in the organic EL element of the present invention, is preferably used as a constituent material of the hole injection layer, hole transport layer, electron blocking layer or light emitting layer of the organic EL element, and more preferably used as a constituent material of the hole transport layer or electron blocking layer.

[0048] The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention has the following properties compared to conventional hole transport materials: (1) good hole injection characteristics, (2) high hole mobility, (3) excellent electron blocking ability, (4) high electron resistance, (5) stable existence in a thin film state, (6) excellent heat resistance, etc. By using the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention in an organic EL element, the following properties can be obtained: (7) high luminous efficiency, (8) low light emission start voltage, (9) low practical driving voltage, (10) long life, etc.

[0049] The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention is excellent in hole injection / transport performance, thin film stability, and durability. Thereby, an organic EL element having a hole injection layer and / or a hole transport layer formed by using the compound as a hole injection material and / or a hole transport material can improve the hole transport efficiency to the light emitting layer, improve the luminous efficiency, and reduce the driving voltage, thereby improving the durability of the element, and obtaining characteristics of high efficiency, low driving voltage, and long life.

[0050] The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention is excellent in electron blocking ability, has high electron resistance, and is stable even in a thin film state, and has a characteristic of confining excitons generated in the light emitting layer. Thereby, an organic EL element having an electron blocking layer formed by using the compound as an electron blocking material has a high luminous efficiency because the probability of recombination of holes and electrons is improved and heat deactivation is suppressed, and the maximum luminous luminance is improved because the driving voltage is reduced and the current resistance is improved.

[0051] The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention is excellent in hole transportability and has a wide band gap. Thereby, an organic EL element having a light emitting layer formed by using the compound as a host material can reduce the driving voltage and improve the luminous efficiency by supporting a fluorescent phosphor, a phosphorescent phosphor, or a delayed fluorescent phosphor called a dopant to form the light emitting layer.

[0052] Therefore, the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention is useful as a material for the hole injection layer, hole transport layer, electron blocking layer, or light-emitting layer of an organic EL element, and can improve the light emission efficiency, driving voltage, and durability of conventional organic EL elements.

Brief Description of the Drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0054] The arylamine compounds having a fluorenyl skeleton-containing heterocyclic structure of the present invention are novel compounds, but these compounds can be synthesized according to methods known per se (see, for example, Patent Document 5).

[0055] Among the arylamine compounds having a fluorenyl skeleton-containing heterocyclic structure represented by the general formula (A), which are preferably used in the organic EL element of the present invention, specific examples of preferred compounds are shown in FIGS. 1 to 8, but the present invention is not limited to these compounds.

[0056] The purification of the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure represented by the general formula (A) can be carried out by known methods such as purification by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization method using a solvent, and sublimation purification method. The identification of the compound can be carried out by NMR analysis. Examples of physical property values include measurement of melting point, glass transition point (Tg), and work function. The melting point is an index of vapor deposition property, the glass transition point (Tg) is an index of stability in a thin film state, and the work function is an index of hole injection property, hole transport property, or electron blocking property.

[0057] The melting point and the glass transition point (Tg) can be measured, for example, using a powder by a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA).

[0058] The work function can be determined, for example, by forming a 100-nm thin film on an ITO substrate and using an ionization potential measuring device (manufactured by Sumitomo Heavy Industries, Ltd., PYS-202).

[0059] As the structure of the organic EL element of the present invention, those composed of an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode sequentially on a substrate, those having an electron blocking layer between the hole transport layer and the light-emitting layer, and those having a hole blocking layer between the light-emitting layer and the electron transport layer can be mentioned. In these multilayer structures, one organic layer can serve multiple roles. For example, one organic layer can be configured to serve as both a hole injection layer and a hole transport layer, or configured to serve as both an electron injection layer and an electron transport layer. Also, it is possible to have a configuration in which two or more organic layers having the same function are stacked, such as a configuration in which two hole transport layers are stacked, a configuration in which two light-emitting layers are stacked, or a configuration in which two electron transport layers are stacked.

[0060] As the anode of the organic EL element of the present invention, electrode materials with a large work function such as ITO and gold are used. As the material for the hole injection layer of the organic EL element of the present invention, porphyrin compounds typified by copper phthalocyanine, starburst-type triphenylamine derivatives, arylamine compounds having two or more triphenylamine structures or carbazolyl structures in the molecule and each connected by a single bond or a divalent group containing no heteroatom, acceptor-type heterocyclic compounds such as hexacyanoazatriphenylene, and coating-type polymer materials can be used.

[0061] As materials for the hole injection layer and the hole transport layer of the organic EL element of the present invention, in addition to the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine (hereinafter abbreviated as TPD), N,N'-diphenyl-N,N'-di(α-naphthyl)-benzidine (hereinafter abbreviated as NPD), benzidine derivatives such as N,N,N',N'-tetrabiphenylylbenzidine, 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (hereinafter abbreviated as TAPC), and arylamine compounds having two or more triphenylamine structures or carbazolyl structures in the molecule and each linked by a single bond or a divalent group containing no hetero atom can be used. These materials may be formed into a film alone, but can also be formed into a film by mixing multiple types, and each can be used as a single layer. Further, a laminated structure of layers formed from these materials alone, a laminated structure of layers formed by mixing, or a laminated structure of a layer formed from these materials alone and a layer formed by mixing multiple types can also be used. Further, as materials for the hole injection / transport layer, coating-type polymer materials such as poly(3,4-ethylenedioxythiophene) (hereinafter abbreviated as PEDOT) / poly(styrenesulfonate) (hereinafter abbreviated as PSS) can be used.

[0062] In addition, for the hole injection layer or the hole transport layer, those obtained by P-doping trisbromophenylamine hexachloroantimonate, a radialene derivative (for example, see Patent Document 6), etc. with respect to the materials usually used in these layers, or polymer compounds having the structure of a benzidine derivative such as TPD in its partial structure can be used.

[0063] As a material for the electron blocking layer of the organic EL element of the present invention, in addition to using the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention, 4,4',4''-tri(N-carbazolyl)triphenylamine (hereinafter abbreviated as TCTA), 9,9-bis[4-(carbazol-9-yl)phenyl]fluorene, 1,3-bis(carbazol-9-yl)benzene (hereinafter abbreviated as mCP), 2,2-bis(4-carbazol-9-ylphenyl)adamantane (hereinafter abbreviated as Ad-Cz), and other carbazole derivatives, and compounds having an electron blocking action such as compounds having a triphenylsilyl group and a triarylamine structure represented by 9-[4-(carbazol-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene can be used. These materials may also serve as materials for the hole transport layer.

[0064] As a material for the light-emitting layer of the organic EL element of the present invention, in addition to using the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention, metal complexes of quinolinol derivatives such as Alq3, various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, polyparaphenylenevinylene derivatives, etc. can be used. Further, the light-emitting layer may be composed of a host material and a dopant material. As the host material, anthracene derivatives are preferably used. In addition to the above-mentioned light-emitting materials including the arylamine compound of the present invention, heterocyclic compounds having an indole ring as a partial structure of a condensed ring, heterocyclic compounds having a carbazole ring as a partial structure of a condensed ring, carbazole derivatives, thiazole derivatives, benzimidazole derivatives, and polydialkylfluorene derivatives can be used. As the dopant material, quinacridone, coumarin, rubrene, perylene and their derivatives, benzopyran derivatives, rhodamine derivatives, and aminostyryl derivatives can be used.

[0065] In addition, it is also possible to use a phosphorescent emitter as the light-emitting material. As the phosphorescent emitter, a phosphorescent emitter of a metal complex such as iridium or platinum can be used. For example, green phosphorescent emitters such as Ir(ppy)3, blue phosphorescent emitters such as FIrpic and FIr6, red phosphorescent emitters such as Btp2Ir(acac), etc. can be mentioned. At this time, as the host material, as a hole injection / transporting host material, in addition to carbazole derivatives such as 4,4'-bis(N-carbazolyl)biphenyl (hereinafter abbreviated as CBP), TCTA, mCP, etc., the arylamine compound of the present invention can be mentioned. As an electron transporting host material, p-bis(triphenylsilyl)benzene (hereinafter abbreviated as UGH2), 2,2',2''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (hereinafter abbreviated as TPBI), etc. can be mentioned. By using such materials, a high-performance organic EL element can be fabricated.

[0066] Doping of the phosphorescent light-emitting material into the host material is preferably carried out by co-evaporation in the range of 1 to 30 weight percent with respect to the entire light-emitting layer in order to avoid concentration quenching.

[0067] In addition, as the light-emitting material, it is also possible to use a material that emits delayed fluorescence, such as CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, 4CzIPN, etc. (see, for example, Non-Patent Document 3).

[0068] As the material for the hole blocking layer of the organic EL element of the present invention, compounds having a hole blocking action, such as phenanthroline derivatives such as bathocuproine (hereinafter abbreviated as BCP), metal complexes of quinolinol derivatives such as BAlq, various rare earth complexes, oxazole derivatives, triazole derivatives, and triazine derivatives, can be used. These materials may also serve as the material for the electron transporting layer.

[0069] As materials for the electron transport layer of the organic EL element of the present invention, 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, and silole derivatives can be used.

[0070] As materials for the electron injection layer of the organic EL element of the present invention, alkali metal salts such as lithium fluoride and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, metal complexes of quinolinol derivatives such as lithium quinolinol, metal oxides such as aluminum oxide, and metals such as ytterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), and cesium (Cs) can be used. The electron injection layer can be omitted by a preferable selection between the electron transport layer and the cathode.

[0071] Furthermore, for the electron injection layer and the electron transport layer, those in which a metal such as cesium is N-doped with respect to the materials usually used for these layers can be used.

[0072] As the cathode of the organic EL element of the present invention, a metal having a low work function such as aluminum, and alloys having a lower work function such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-magnesium alloy are used as electrode materials.

[0073] These materials used for each layer constituting the organic EL element can form a thin film by known methods such as vapor deposition method, spin coating method, and inkjet method. Further, these materials may be formed into a film alone, but can also be formed into a film by mixing a plurality of types, and each can be used as a single layer. Further, a laminated structure of layers formed from these materials alone, a laminated structure of layers formed by mixing, or a laminated structure of a layer formed from these materials alone and a layer formed by mixing a plurality of types may be used.

Example

[0074] Hereinafter, embodiments of the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0075] 〔Example 1〕 <Synthesis of bis(biphenyl-4-yl)-{3-(7,7-dimethyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (12))> Into a reaction vessel, 7.0 g of 5-bromo-7,7-dimethyl-7H-12-oxa-indeno[1,2-a]fluorene, 12.1 g of bis(biphenyl-4-yl)-{3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl}-amine, 0.3 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and 2.4 g of sodium hydrogen carbonate were charged, and the mixture was refluxed and stirred overnight under a THF / H2O mixed solvent. After cooling, ethyl acetate / H2O was added to the system, and the organic layer was taken out by extraction and liquid separation operations, and concentrated to obtain a crude product. The obtained crude product was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 12.2 g (yield: 92.9%) of a white powder of bis(biphenyl-4-yl)-{3-(7,7-dimethyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (12)).

[0076]

Chem.

[0077] Regarding the obtained white powder, 1 37 hydrogen signals were detected by 1H-NMR (CDCl3) to identify the structure. δ (ppm) = 8.30 (1H), 7.68 (1H), 7.62 (1H), 7.61 - 7.50 (11H), 7.49 (1H), 7.44 (6H), 7.39 (2H), 7.33 (7H), 7.18 (1H), 1.61 (6H).

[0078] 〔Example 2〕 <Synthesis of Biphenyl-4-yl-{4-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-phenyl-amine (Compound (14))> Into a reaction vessel, 10.0 g of 5-bromo-7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene, 9.0 g of 4-(biphenyl-4-yl-phenyl-amino)-phenylboronic acid, 0.3 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and 3.5 g of sodium hydrogen carbonate were charged, and the mixture was refluxed and stirred overnight under a THF / H2O mixed solvent. After cooling, ethyl acetate / H2O was added to the system, and the organic layer was taken out by extraction and liquid separation operations, and concentrated to obtain a crude product. The obtained crude product was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 8.5 g (yield: 56.9%) of a pale yellow powder of biphenyl-4-yl-{4-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-phenyl-amine (Compound (14)).

[0079]

Chemical formula

[0080] Regarding the obtained pale yellow powder, 1 37 hydrogen signals below were detected by 1H-NMR (CDCl3) to identify the structure. δ (ppm) = 8.38 (1H), 7.78 (1H), 7.73 (1H), 7.63 (2H), 7.56 (2H), 7.49 (7H), 7.39 - 7.20 (22H), 7.11 (1H).

[0081] 〔Example 3〕 <Synthesis of Biphenyl-4-yl-{3-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-phenyl-amine (Compound (52))> Into a reaction vessel, 7.0 g of 5-bromo-7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene, 7.4 g of biphenyl-4-yl-phenyl-{3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl}-amine, 0.2 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and 2.4 g of sodium hydrogen carbonate were charged, and the mixture was refluxed and stirred overnight under a mixed solvent of THF / H2O. After cooling, ethyl acetate / H2O was added to the system, and the organic layer was taken out by extraction and liquid separation operations, and concentrated to obtain a crude product. The obtained crude product was purified by recrystallization with an acetone solvent to obtain 8.5 g (yield: 81.3%) of white powder of biphenyl-4-yl-{3-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-phenyl-amine (Compound (52)).

[0082]

Chemical formula

[0083] Regarding the obtained white powder, 1 37 hydrogen signals were detected by 1H-NMR (CDCl3) to identify the structure. δ (ppm) = 8.35 (1H), 7.69 (1H), 7.62 (1H), 7.57 (2H), 7.54 - 7.19 (30H), 7.17 (1H), 7.06 (1H).

[0084] 〔Example 4〕 <Synthesis of bis(biphenyl-4-yl)-{4-(7,7-dimethyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (7))> Into a reaction vessel, 4.0 g of 5-(4-chlorophenyl)-7,7-dimethyl-7H-12-oxa-inden[1,2-a]fluorene, 4.2 g of bis(biphenyl-4-yl)amine, 0.1 g of bis(tri-t-butylphosphine)palladium(0), and 3.0 g of sodium t-butoxide were charged, and the mixture was refluxed and stirred overnight under a toluene solvent. After cooling to room temperature, the filtrate obtained by filtration was concentrated to obtain a crude product. The obtained crude product was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 5.2 g (yield: 75.4%) of yellow powder of bis(biphenyl-4-yl)-{4-(7,7-dimethyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (7)).

[0085] [Chemical formula]

[0086] Regarding the obtained yellow powder, 1 37 hydrogen signals were detected by 1H-NMR (CDCl3) to identify the structure. δ (ppm) = 8.29 (1H), 7.74 (1H), 7.69 (1H), 7.62 (6H), 7.58 (4H), 7.51 - 7.41 (7H), 7.39 - 7.30 (10H), 7.22 (1H), 1.60 (6H).

[0087] [Example 5] [Synthesis of bis(biphenyl-4-yl)-{4-(7,7-diphenyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (24))] Into a reaction vessel, 8.1 g of 5-(4-chlorophenyl)-7,7-diphenyl-7H-12-oxa-inden[1,2-a]fluorene, 5.5 g of bis(biphenyl-4-yl)-amine, 0.2 g of bis(tri-t-butylphosphine)palladium(0), and 3.0 g of sodium t-butoxide were charged, and the mixture was refluxed with stirring overnight under a toluene solvent. After cooling, the filtrate obtained by filtration was concentrated to obtain a crude product. The obtained crude product was purified by crystallization using a mixed solvent of monochlorobenzene / acetone to obtain 9.8 g (yield: 78.1%) of a white powder of bis(biphenyl-4-yl)-{4-(7,7-diphenyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (24)).

[0088] [Chemical formula]

[0089] Regarding the obtained white powder, 1 41 hydrogen signals were detected by 1H-NMR (CDCl3), and the structure was identified. δ (ppm) = 8.35 (1H), 7.75 (1H), 7.71 (1H), 7.60 (4H), 7.55 (4H), 7.51 (2H), 7.49 - 7.40 (7H), 7.34 (2H), 7.33 - 7.26 (12H), 7.25 - 7.18 (7H).

[0090] [Example 6] [Synthesis of (biphenyl-2-yl)-(biphenyl-4-yl)-{4-(7,7-dimethyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (26))] Into a reaction vessel, 9.0 g of (biphenyl-4-yl)-(biphenyl-4-yl)-{4-(7,7-dimethyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-phenyl}-amine, 3.9 g of 2-bromobiphenyl, 0.1 g of palladium(II) acetate, 0.2 g of tri-t-butylphosphine, and 2.0 g of sodium t-butoxide were charged, and the mixture was refluxed and stirred for 3 hours under a toluene solvent. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The obtained crude product was purified by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 7.6 g (yield: 68.4%) of a white powder of (biphenyl-2-yl)-(biphenyl-4-yl)-{4-(7,7-dimethyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (26)).

[0091] [Chemical formula]

[0092] Regarding the obtained white powder, 1 41 hydrogen signals were detected by 1H-NMR (CDCl3) to identify the structure. δ (ppm) = 8.33 (1H), 7.68 (1H), 7.55 (2H), 7.51 (1H), 7.50 - 7.38 (10H), 7.37 - 7.08 (24H), 6.91 (2H).

[0093] [Example 7] [Synthesis of diphenyl-{1-(7,7-diphenyl-7H-12-oxa-inden[1,2-a]fluorene-5-yl)-naphthalen-4-yl}-amine (Compound (43))] Into a reaction vessel, 8.7 g of 5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene, 6.0 g of diphenylamino-naphthalen-4-yl-trifluoromethanesulfonate, 0.2 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and 1.7 g of sodium hydrogen carbonate were charged, and the mixture was refluxed and stirred overnight under a THF / H2O mixed solvent. After cooling, methanol was added to the system, and the precipitated solid was filtered to obtain a crude product. The obtained crude product was purified by crystallization using a toluene / acetone mixed solvent to obtain 4.4 g (yield: 45.9%) of a pale yellow powder of diphenyl-{1-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-naphthalen-4-yl}-amine (Compound (43)).

[0094] [Chemical formula]

[0095] Regarding the obtained pale yellow powder, 1 35 hydrogen signals were detected by 1H-NMR (CDCl3), and the structure was identified. δ (ppm) = 8.40 (1H), 8.07 (1H), 7.68 (1H), 7.61 (1H), 7.56 (1H), 7.52 (1H), 7.50 (1H), 7.46 (1H), 7.42 (1H), 7.40 - 7.17 (18H), 7.13 (4H), 6.97 (3H), 6.71 (1H).

[0096] [Example 8] [Synthesis of bis(biphenyl-4-yl)-{3-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (61))] Into a reaction vessel, 10.0 g of 5-bromo-7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene, 12.9 g of bis(biphenyl-4-yl)-{3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl}-amine, 0.3 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and 2.6 g of sodium hydrogen carbonate were charged, and the mixture was refluxed and stirred for 2 hours under a THF / H2O mixed solvent. After cooling, ethyl acetate / H2O was added to the system, and the organic layer was taken out by extraction and liquid separation operations, and concentrated to obtain a crude product. The obtained crude product was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 14.5 g (yield: 87.9%) of white powder of bis(biphenyl-4-yl)-{3-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-phenyl}-amine (Compound (61)).

[0097] [Chemical formula]

[0098] Regarding the obtained white powder, 1 41 hydrogen signals were detected by 1H-NMR (CDCl3) to identify the structure. δ(ppm)=8.32(1H),7.66(1H),7.60(1H),7.55(4H),7.49(4H),7.48 - 7.38(8H),7.35(2H),7.32 - 7.26(5H),7.24(8H),7.21 - 7.12(7H).

[0099] [Example 9] [Synthesis of bis(biphenyl-4-yl)-{5-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-biphenyl-2-yl}-amine (Compound (94))] Into a reaction vessel, 4.3 g of 5-bromo-7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene, 6.3 g of bis(biphenyl-4-yl)-{5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-biphenyl-2-yl}-amine, 0.1 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and 1.1 g of sodium hydrogen carbonate were charged, and the mixture was refluxed and stirred for 5 hours under a THF / H2O mixed solvent. After cooling, methanol was added to the system, and the precipitated solid was filtered to obtain a crude product. The obtained crude product was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 7.1 g (yield: 91.6%) of a pale yellow powder of bis(biphenyl-4-yl)-{5-(7,7-diphenyl-7H-12-oxa-indeno[1,2-a]fluorene-5-yl)-biphenyl-2-yl}-amine (Compound (94)).

[0100]

Chemical formula

[0101] Regarding the obtained pale yellow powder, 1 45 hydrogen signals were detected by 1H-NMR (CDCl3), and the structure was identified. δ(ppm)=8.37(1H),7.79(1H),7.72(1H),7.62(1H),7.60(1H),7.53(5H),7.48(3H),7.44 - 7.34(9H),7.34 - 7.18(17H),7.07(6H).

[0102] [Example 10] Regarding the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure obtained in the above example, the melting point and glass transition point were measured by a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA). The results are shown in Table 1.

[0103]

Table 1

[0104] From Table 1, it can be seen that the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure represented by the general formula (A) has a glass transition point of 120°C or higher, indicating that the thin film state is stable.

[0105] [Example 11] Using the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure obtained in the above example, a vapor deposition film with a thickness of 100 nm was formed on an ITO substrate, and the work function was measured by an ionization potential measuring device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.). The results are shown in Table 2.

[0106] [Table 2]

[0107] As shown in Table 2, the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure represented by the general formula (A) has a higher work function value compared to the work function of 5.4 eV of common hole transport materials such as NPD and TPD, shows a suitable energy level, and has good hole transport ability.

[0108] [Example 12] The organic EL device was fabricated by vapor-depositing a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, an electron transport layer 7, an electron injection layer 8, a cathode 9, and a capping layer 10 in this order on a glass substrate 1 on which a reflective ITO electrode had been previously formed as a transparent anode as shown in the organic EL device configuration of FIG. 9. Specifically, a glass substrate 1 on which an ITO with a thickness of 50 nm, a reflective film of a silver alloy with a thickness of 100 nm, and an ITO with a thickness of 5 nm were sequentially formed was ultrasonically cleaned in isopropyl alcohol for 20 minutes, and then dried on a hot plate heated to 250°C for 10 minutes. Then, after performing UV ozone treatment for 15 minutes, this ITO-coated glass substrate was placed in a vacuum vapor deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, as the hole injection layer 3 covering the transparent anode 2, an electron acceptor (Acceptor-1) of the following structural formula and a compound (HTM-1) of the following structural formula were subjected to co-evaporation at an evaporation rate ratio of Acceptor-1:compound (HTM-1) = 3:97 to form a film with a thickness of 10 nm. On top of this hole injection layer 3, a compound (HTM-1) of the following structural formula was formed as the hole transport layer 4 with a thickness of 140 nm. On top of this hole transport layer 4, the compound (12) obtained in Example 1 was formed as the electron blocking layer 5 with a thickness of 5 nm. On top of this electron blocking layer 5, a compound (EMD-1) of the following structural formula and a compound (EMH-1) of the following structural formula were subjected to co-evaporation as the light-emitting layer 6 at an evaporation rate ratio of compound (EMD-1):EMH-1 = 5:95 to form a film with a thickness of 20 nm. On top of this light-emitting layer 6, a compound (ETM-1) of the following structural formula and a compound (ETM-2) of the following structural formula were subjected to co-evaporation as the electron transport layer 7 at an evaporation rate ratio of compound (ETM-1):(ETM-2) = 50:50 to form a film with a thickness of 30 nm. On top of this electron transport layer 7, lithium fluoride was formed as the electron injection layer 8 with a thickness of 1 nm. On top of this electron injection layer 8, a magnesium-silver alloy was formed as the cathode 9 with a thickness of 12 nm. Finally, a compound (CPL-1) of the following structure was formed as the capping layer 10 with a thickness of 60 nm. Table 3 summarizes the measurement results of the light-emitting characteristics obtained by applying a DC voltage to the organic EL device fabricated in Example 12 above at room temperature in air.

[0109]

Chemical formula

[0110]

Chemical formula

[0111]

Chem.

[0112] 〔Example 13〕 In Example 12, an organic EL device was fabricated under the same conditions, except that the compound (14) obtained in Example 2 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. The measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air are summarized in Table 3.

[0113] 〔Example 14〕 In Example 12, an organic EL device was fabricated under the same conditions, except that the compound (52) obtained in Example 3 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. The measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air are summarized in Table 3.

[0114] 〔Example 15〕 In Example 12, an organic EL device was fabricated under the same conditions, except that the compound (7) obtained in Example 4 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. The measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air are summarized in Table 3.

[0115] 〔Example 16〕 In Example 12, an organic EL device was fabricated under the same conditions, except that the compound (24) obtained in Example 5 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. The measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air are summarized in Table 3.

[0116] 〔Example 17〕 In Example 12, an organic EL device was fabricated under the same conditions except that the compound (26) obtained in Example 6 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. Table 3 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air.

[0117] [Example 18] In Example 12, an organic EL device was fabricated under the same conditions except that the compound (43) obtained in Example 7 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. Table 3 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air.

[0118] [Example 19] In Example 12, an organic EL device was fabricated under the same conditions except that the compound (61) obtained in Example 8 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. Table 3 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air.

[0119] [Example 20] In Example 12, an organic EL device was fabricated under the same conditions except that the compound (94) obtained in Example 9 was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. Table 3 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air.

[0120] [Comparative Example 1] For comparison, in Example 12, an organic EL device was fabricated under the same conditions except that the compound (HTM-2) of the following structural formula (see, for example, Patent Document 5) was used as the material for the electron blocking layer 5 instead of the compound (12) obtained in Example 1. Table 3 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device fabricated under the same measurement conditions at room temperature in the air.

[0121]

Chem.

[0122] 〔Comparative Example 2〕 For comparison, in Example 12, an organic EL element was fabricated under the same conditions except that the compound (HTM-3) of the following structural formula (see, for example, Patent Document 5) was used as the material of the electron blocking layer 5 instead of the compound (12) obtained in Example 1. Table 3 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL element fabricated under the same measurement conditions at room temperature in the air.

[0123]

Chem.

[0124] Using the organic EL elements fabricated in the above Examples and Comparative Examples, the measured device lifetime was defined as the time until the emission luminance decayed to 950 cd / m 2 when constant current driving was performed with the emission luminance at the start of emission (initial luminance) being 1000 cd / m 2 (corresponding to 95% when the initial luminance is 100%: 95% decay).

[0125]

Table 3

[0126] As shown in Table 3, at a current density of 10 mA / cm 2When a current was passed through the device, the luminous efficiency of the organic EL devices of Examples 12 to 20 was as high as 8.52 to 11.27 cd / A, compared to 7.98 to 8.28 cd / A of the organic EL devices of Comparative Examples 1 and 2. Also, in terms of power efficiency, the organic EL devices of Examples 12 to 20 were highly efficient at 7.50 to 10.14 lm / W, compared to 7.03 to 7.29 lm / W of the organic EL devices of Comparative Examples 1 and 2. Furthermore, in terms of device lifetime (95% attenuation), it can be seen that the organic EL devices of Examples 12 to 20 had a longer lifetime of 349 to 791 hours, compared to 298 to 327 hours of the organic EL devices of Comparative Examples 1 and 2.

[0127] As is clear from the above results, the organic EL device using the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention has a high hole mobility and uses an arylamine compound having excellent electron blocking ability. Therefore, it has been found that an organic EL device with high luminous efficiency and long lifetime can be realized compared to conventional organic EL devices.

Industrial Applicability

[0128] The organic EL device using the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention can improve the luminous efficiency and the durability of the organic EL device, and can be applied to, for example, household electrical appliances and lighting applications.

[0129] In addition, the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure of the present invention can be used not only in organic EL devices but also in electronic devices in fields such as electrophotographic photoreceptors, image sensors, photoelectric conversion elements, and solar cells.

Explanation of Reference Numerals

[0130] 1 Glass substrate 2 Transparent anode 3 Hole injection layer 4 Hole transport layer 5 Electron blocking layer 6 Light-emitting layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 10 Capping layer

Claims

1. An arylamine compound having a fluorenyl skeleton-containing heterocyclic structure, represented by the following general formula (A). 【Chemical 1】 (In the formula, R １ to R １１ may be the same as or different from each other, and each represents a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group.) L represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group. n is 1. Ar １ and Ar ２ may be the same as or different from each other and represent a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group. X represents an oxygen atom. Also, L and Ar １ , and Ar １ and Ar ２ do not combine with each other to form a ring.)

2. R １０ and R １１ is a substituted or unsubstituted methyl group or a substituted or unsubstituted phenyl group, and the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to Claim 1.

3. The arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to Claim 1 or 2, wherein L is a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, or a substituted or unsubstituted naphthylene group.

4. An organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched therebetween, wherein the organic layer contains the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to any one of Claims 1 to 3.

5. The organic electroluminescence device according to Claim 4, wherein the organic layer is an electron blocking layer.

6. The organic electroluminescence device according to Claim 4, wherein the organic layer is a hole transport layer.

7. The organic electroluminescence device according to Claim 4, wherein the organic layer is a hole injection layer.

8. The organic electroluminescence device according to Claim 4, wherein the organic layer is a light emitting layer.

9. An electronic device using an electronic component having a pair of electrodes and at least one organic layer sandwiched therebetween, wherein the organic layer contains the arylamine compound having a fluorenyl skeleton-containing heterocyclic structure according to any one of Claims 1 to 3.

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