JP2007123713A - Organic electroluminescence element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL (ElectroLuminescence) element which can have a high heat resistance and be driven with a low voltage. <P>SOLUTION: In the organic EL element having multiple organic layers including a luminous layer, a hole transport layer, and a hole injection layer; the hole transport layer contains a compound which has a glass transition temperature (Tg) of 130°C or higher and is expressed by formula [1]. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence element used for a planar light source and display. More specifically, the present invention relates to a long-life organic electroluminescence element that has high heat resistance and can be driven at a low voltage.

  An organic electroluminescent element is composed of an element in which a single layer or a multilayer organic layer is formed between an anode and a cathode. Here, a single layer type organic electroluminescent element is composed of only a light emitting layer between an anode and a cathode. This element is called a single-layer organic electroluminescence element. On the other hand, a multilayer type (also referred to as a laminated type) organic electroluminescent element means that, in addition to the light emitting layer, the injection of holes and electrons into the light emitting layer is facilitated, and the recombination of holes and electrons in the light emitting layer. refers for the purpose of or to smoothly perform the binding, hole injection layer, a hole transport layer, a hole blocking layer, the one obtained by laminating an electron injection layer. Typical device configurations of the multilayer organic electroluminescence device include (1) anode / hole injection layer / light emitting layer / cathode, (2) anode / hole injection layer / hole transport layer / light emitting layer / cathode, (3) Anode / hole injection layer / light emitting layer / electron injection layer / cathode, (4) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode, (5) Anode / hole Injection layer / light emitting layer / hole blocking layer / electron injection layer / cathode, (6) anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron injection layer / cathode, (7) anode It is possible to consider an element structure in which a multi-layer structure such as: / light emitting layer / hole blocking layer / electron injection layer / cathode, (8) anode / light emitting layer / electron injection layer / cathode, etc. Here, when there is a single layer responsible for injecting and transporting holes between the anode and the light emitting layer, this is often referred to as a hole injecting and transporting layer or simply a hole injecting layer (referred to as a carrier injecting layer). Sometimes). In addition, when the layer responsible for injecting holes and the layer responsible for transport are formed between the anode and the light-emitting layer, the layer that is in contact with the anode and mainly promotes the injection of holes is the hole injection layer, the positive layer. A layer mainly responsible for transporting holes between the hole injection layer and the light emitting layer is referred to as a hole transport layer. Regarding such multilayering (stacking) of organic electroluminescent elements, for example, Shizutoki Tokito, Chiba Adachi, Hideyuki Murata, Organic EL Display, page 102, Ohmsha (published in 2004), etc. And the references cited therein.

  On the other hand, in recent years, with the expansion of the application field of organic electroluminescence elements, heat resistance exceeding 100 ° C. has been required as element performance (remaining important issues and practical technologies of organic LED elements) 4 pages, Organic Electronics Materials Study Group, 1999). There are various factors that can influence the heat resistance of the device. One of them is that the glass transition temperature (Tg) of the material that composes the device has a significant effect on the heat resistance of the device. Yes. That is, a phenomenon has been pointed out that when the temperature of the element exceeds the Tg of the constituent material due to the use environment of the element and the heat generated during driving, the material crystallizes and a non-light emitting region called a dark spot is generated. . In addition, it has been empirically revealed that a device having higher heat resistance generally has a longer lifetime, and therefore, development of a material exhibiting a higher Tg is required.

  By the way, it is empirically known that the phenanthrene structure generally shows high heat resistance, and an organic electroluminescence device using an aromatic tetraamine compound having a phenanthrene structure in a hole injecting and transporting layer is disclosed in JP-A-8-20771. However, it has not been clarified about the Tg of the compound represented by the general formula [1] of the present application.

In addition, the driving voltage of the organic electroluminescence element is determined by the individual material and element structure constituting the element, but in recent years, it has been required that the element performance can be driven at a low voltage (low voltage driving). As described above, research on multilayered elements has been actively conducted. For example, as an organic electroluminescence device having a hole injection layer or a hole transport layer, WO98 / 30071, JP2000-309566, JP2004-155705, JP2005-268228, Japanese Laid-Open Patent Publication No. 2005-276832 and Japanese Patent Laid-Open Publication No. 2005-276833 are known, but an example in which a material represented by the general formula [3] of the present application is used for the hole transport layer is not disclosed.

Japanese Patent Laid-Open No. 8-20771 WO98 / 30071 Publication JP 2000-309566 JP JP 2004-155705 A JP 2005-268228 A JP 2005-276832 A JP 2005-276833 A

  In order to develop a device having heat resistance exceeding 100 ° C., it is necessary to construct the device using a material having a higher Tg, specifically, a Tg of about 130 ° C. or more. In addition Factors on the life of the element is simply not determined only by the Tg of the material used, also highly dependent on the chemical structure of the materials used. An element made using the materials exemplified in Japanese Patent Application Laid-Open No. Hei 8-20771 mentioned in the background art does not satisfy the heat resistance and life of the element currently required, and therefore has higher heat resistance and life. There has been a need for a hole transport material to provide. In addition, the driving voltage, which is one of the device performances, varies greatly depending on the individual materials and device configuration that form the organic layer, so it is not determined solely by the properties of the hole transport material, and can therefore be driven at a low voltage. In order to construct such a device, it was necessary to select a material suitable for the hole injection material and the electron injection material used together with the hole transport material.

［式中、R¹〜R¹⁶は、それぞれ独立に、水素原子、１価の脂肪族炭化水素基、もしくは１価の芳香族炭化水素基を表し、Ar¹〜Ar⁶は、それぞれ独立に、１価の芳香族炭化水素基を表す。］ As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention. That is, the present invention is an organic electroluminescence device having a multilayer organic layer including at least a light emitting layer, a hole transport layer, and a hole injection layer sandwiched between a pair of electrodes, the hole transport layer Relates to an organic electroluminescence device comprising a compound represented by the following general formula [1] having a glass transition temperature (Tg) of 130 ° C. or higher.
General formula [1]

[Wherein, R ^{1 to} R ¹⁶ each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group, or a monovalent aromatic hydrocarbon group, and Ar ^{1 to} Ar ⁶ are each independently, Represents a monovalent aromatic hydrocarbon group. ]

［式中、Z¹は連結基であり、単結合、２価の脂肪族炭化水素基、２価の芳香族炭化水素基、酸素原子、硫黄原子のいずれかを表す。R^a1〜R^a6は、それぞれ独立に、水素原子、１価の脂肪族炭化水素基、１価の芳香族炭化水素基、もしくはジアリールアミノ基を表すが、R^a1〜R^a6のいずれか一つはジアリールアミノ基である。ｂ１およびｂ２は０〜４の整数を、ｂ３〜ｂ６は０〜５の整数を表し、ｂ１＋ｂ２＋ｂ３＋ｂ４＋ｂ５＋ｂ６≧１である。］
一般式［３］

［式中、R^a11〜R^a14は、それぞれ独立に、水素原子、アルコキシル基、もしくはシアノ基を表すが、全てが同時に水素原子となることはない。］ In addition, the present invention relates to the organic electroluminescence element, wherein the hole injection layer comprises a compound represented by the following general formula [2] or general formula [3].
General formula [2]

[Wherein, Z ¹ is a linking group and represents a single bond, a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, an oxygen atom or a sulfur atom. R ^{a1 to} R ^a6 each independently represent a hydrogen atom, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, or a diarylamino group, and any one of R ^{a1 to} R ^a6 Is a diarylamino group. b1 and b2 represent an integer of 0 to 4, b3 to b6 represent an integer of 0 to 5, and b1 + b2 + b3 + b4 + b5 + b6 ≧ 1. ]
General formula [3]

[Wherein, R ^{a11 to} R ^a14 each independently represent a hydrogen atom, an alkoxyl group, or a cyano group, but they are not all simultaneously hydrogen atoms. ]

  The present invention further includes an electron injection layer between the cathode and the light emitting layer, and the electron injection layer is selected from oxadiazole derivatives, triazole derivatives, silole derivatives, and triarylphosphine oxide derivatives. It is related with the said organic electroluminescent element characterized by including at least one.

  Further, the present invention has a glass transition temperature of all of the material forming the organic layer (Tg) of, relating to the organic electroluminescent device is 130 ° C. or higher.

［式中、Ar⁷〜Ar¹²は、それぞれ独立に、フェニル基、１−ナフチル基、２−ナフチル基、ｏ−ビフェニリル基、ｍ−ビフェニリル基、およびｐ−ビフェニリル基より選ばれる１価の芳香族炭化水素基を表す。］ Moreover, this invention relates to the positive hole transport layer forming material of the organic electroluminescent element represented by following General formula [4].
General formula [4]

[Wherein Ar ^{7 to} Ar ¹² are each independently a monovalent fragrance selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. Represents a group hydrocarbon group. ]

  Since the organic electroluminescence device of the present invention has high heat resistance and a long life that can be driven at a low voltage, it can be suitably used as a flat panel display such as a wall-mounted television or a flat light emitter. It can be applied to light sources such as machines and printers, light sources such as liquid crystal displays and instruments, display boards, marker lamps, and lighting.

Hereinafter, the present invention will be described in detail. First, the compound represented by the general formula [1] will be described. R ^{1 to} R ¹⁶ in the general formula [1] each independently represent a hydrogen atom, a monovalent aliphatic hydrocarbon group, or a monovalent aromatic hydrocarbon group.

  Here, the monovalent aliphatic hydrocarbon group refers to a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, such as an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group. Can be given.

  Therefore, as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, hexyl group, heptyl group, octyl group, C1-C18 alkyl groups, such as a decyl group, a dodecyl group, a pentadecyl group, and an octadecyl group, are mentioned.

  Examples of the alkenyl group include vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-octenyl group, 1-decenyl group, 1 -An alkenyl group having 2 to 18 carbon atoms such as an octadecenyl group.

  Examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-octynyl group, 1-decynyl group and 1-octadecynyl group. Examples thereof include alkynyl groups having 2 to 18 carbon atoms.

  In addition, the cycloalkyl group has a carbon number such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclooctadecyl group, 2-bornyl group, 2-isobornyl group, 1-adamantyl group. Examples thereof include 3 to 18 cycloalkyl groups.

  Furthermore, examples of the monovalent aromatic hydrocarbon group include monovalent monocyclic, condensed ring, and ring-aggregated aromatic hydrocarbon groups having 6 to 30 carbon atoms. Here, examples of the monovalent monocyclic aromatic hydrocarbon group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 2,4-xylyl group, a p-cumenyl group, and a mesityl group. Examples thereof include monovalent monocyclic aromatic hydrocarbon groups having 6 to 30 carbon atoms.

  Examples of the monovalent condensed ring aromatic hydrocarbon group include 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 5-anthryl group, 1-phenanthryl group, 9-phenanthryl group, 1-acenaphthyl group, 2-azurenyl group, 1-pyrenyl group, 2-triphenylyl group, 1-pyrenyl group, 2-pyrenyl group, 1-perylenyl group, 2-perylenyl group, 3-perenylenyl group, 2-trephenylenyl group, Examples thereof include monovalent condensed ring hydrocarbon groups having 10 to 30 carbon atoms such as 2-indenyl group, 1-acenaphthylenyl group, 2-naphthacenyl group, and 2-pentacenyl group.

  The monovalent ring-aggregated aromatic hydrocarbon group has 12 carbon atoms such as o-biphenylyl group, m-biphenylyl group, p-biphenylyl group, terphenylyl group, 7- (2-naphthyl) -2-naphthyl group and the like. To 30 monovalent ring-assembled hydrocarbon groups.

The carbon number of the monovalent aliphatic hydrocarbon group or monovalent aromatic hydrocarbon group in R ^{1 to} R ¹⁶ described above is preferably 1 to 8, and more preferably 1 to 4. This is because, when the number of carbon atoms of these substituents increases, the molecular weight increases, and thus there is a concern that the vapor deposition property is deteriorated when an element is formed by vapor deposition. The vapor deposition property of the material is not necessarily proportional because the structure of the material molecule itself or the interaction between the molecules affects the material, but it is generally recognized that the vapor deposition becomes difficult as the molecular weight increases.

Therefore, R ^{1 to} R ¹⁶ described above are preferably a hydrogen atom or a monovalent aliphatic hydrocarbon group, more preferably a hydrogen atom or an alkyl group, and still more preferably a hydrogen atom or a carbon number of 1 to 4 is an alkyl group, and most preferably a hydrogen atom.

Next, Ar ^{1 to} Ar ⁶ in the general formula [1] will be described. Ar ^{1 to} Ar ⁶ each independently represents a monovalent aromatic hydrocarbon group. The monovalent aromatic hydrocarbon group here is synonymous with the above-described monovalent aromatic hydrocarbon group.

The monovalent aromatic hydrocarbon group of Ar ^{1 to} Ar ⁶ is preferably selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. A monovalent aromatic hydrocarbon group, more preferably a monovalent aromatic hydrocarbon group selected from a phenyl group, a 1-naphthyl group, an m-biphenylyl group, and a p-biphenylyl group.

Furthermore, Ar ¹ and Ar ² are preferably monovalent aromatic hydrocarbon groups selected from a phenyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group, A monovalent aromatic hydrocarbon group selected from a phenyl group, an m-biphenylyl group, and a p-biphenylyl group is more preferable, and a phenyl group is more preferable. Ar ^{3 to} Ar ⁶ are preferably monovalent aromatic carbonization selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. A hydrogen group, more preferably a monovalent aromatic hydrocarbon group selected from a phenyl group, a 1-naphthyl group, an m-biphenylyl group, and a p-biphenylyl group, still more preferably a phenyl group or 1- Naphthyl group.

Therefore, the compound represented by the general formula [4] is preferably used as the hole transport layer forming material of the organic electroluminescence device of the present invention. Ar ^{7 to} Ar ¹² in the general formula [4] are each independently 1 selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. A divalent aromatic hydrocarbon group, and Ar ⁷ and Ar ⁸ are monovalent aromatic hydrocarbon groups selected from a phenyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. Of these, a phenyl group is more preferable. Ar ^{9 to} Ar ¹² are more preferably a monovalent aromatic hydrocarbon group selected from a phenyl group, a 1-naphthyl group, an m-biphenylyl group, and a p-biphenylyl group. -More preferably, it is a naphthyl group. Further, when Ar ⁹ and Ar ¹¹ are 1-naphthyl groups, Ar ¹⁰ and Ar ¹² are monovalent aromatic groups selected from a phenyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. It is preferably a hydrocarbon group.

  The hole transport layer forming material of the organic electroluminescence device of the present invention has a Tg of 130 ° C. or higher, more preferably 150 ° C. or higher, and particularly preferably 170 ° C. or higher. As a result, it can withstand the high temperature during vapor deposition, and the formed film is stable. When used in an element, it exhibits excellent stability in a high temperature environment or a heat generation environment.

  The hole transport layer forming material has been described above in the present invention. The molecular weight of these hole transport layer forming materials is preferably 1500 or less, more preferably 1300 or less, and even more preferably 1200 or less.

  Table 1 shows typical examples of hole transport layer forming materials that can be used in the present invention, but the present invention is not limited to these.

Hole transport layer has the ability to quickly transport holes from the hole injection layer to the light-emitting layer, and can form a layer with excellent adhesion to the hole injection layer and the light-emitting layer and thin film formation Although a transport material is used, the hole transport layer forming material represented by the general formula [4] of the present invention can be preferably used. In general, a hole transport material has a high hole mobility and an ionization energy of usually about 5.2 to 5.5 eV, and a material that transports holes to a light emitting layer with a lower electric field strength is preferable. It is preferable that the mobility is at least 10 ⁻⁶ cm ² / V · sec when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. Further, the hole transport layer forming material of the present invention satisfies such requirements, and of course, it can be used in combination with two or more types, that is, mixed, co-deposited, laminated, etc. Can also be used. In order to form the hole transport layer, it is thinned by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. Although the film thickness of a positive hole transport layer does not have a restriction | limiting in particular, Usually, they are 5 nm-5 micrometers.

  The purification method for the hole transport layer forming material used in the present invention is not particularly limited, and includes a sublimation purification method, a recrystallization method, a reprecipitation method, a zone melting method, a column purification method, an adsorption method, and the like. Although a combination of methods can be performed, it is preferable to use a recrystallization method. Moreover, in the hole transport layer forming material which has sublimation property, it is preferable to use a sublimation purification method. In sublimation purification, it is preferable to employ a method in which a sublimation boat is maintained at a temperature lower than the sublimation temperature of the hole transport layer forming material and impurities to be sublimated are removed in advance. In addition, it is desirable to apply a temperature gradient to the portion where the sublimate is collected so that the sublimate is dispersed in the impurities and the target product. Sublimation purification as described above is purification that separates impurities, and can be applied to the present invention.

  Furthermore, although the hole transport layer forming material described above is exclusively used for the hole transport layer in the organic electroluminescence element of the present invention, the organic electroluminescence element of the organic electroluminescence element may be used as long as the heat resistance, life, and driving voltage of the element are not impaired. You may use with the well-known hole transport material currently used for the hole transport layer. For example, known hole transport materials listed in Table 2 below can be used together with the hole transport layer forming material of the present invention.

Next, the hole injection layer has a hole injection material that exhibits an excellent hole injection effect with respect to the light emitting layer, and that can form a hole injection layer having excellent adhesion to the anode interface and excellent thin film formation. Used. The hole injection material needs to have a high hole mobility and a small ionization energy of usually 5.5 eV or less. Such a hole injection layer is preferably a material that transports holes to the light emitting layer with a lower electric field strength, and further has a hole mobility of at least when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. What is 10 ^<-6 > cm ^{< 2} > / V * second is preferable. The hole injecting material that can be used in the organic electroluminescence device of the present invention is not particularly limited as long as it has the above-mentioned preferable properties, and conventionally used as a charge transport material for holes in photoconductive materials. Or any known one used for the hole injection layer of the organic electroluminescence device can be selected and used. In order to form this hole injection layer, the film is thinned by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. The thickness of the hole injection layer is not particularly limited, but is usually 5 nm to 5 μm.

In particular, the compound represented by the general formula [2] can be suitably used as the hole injection layer of the present invention. In the general formula [2], the divalent aliphatic hydrocarbon group is, for example, an ethylidene group, a 2,2-propylidene group, a 2,2-diphenylmethylidene group, a vinylidene group, a cyclopentylidene group, or a cyclohexylidene group. C1-C18 alkylidene groups, such as a group, C1-C18 alkylidene groups, such as a methylene group, ethylene group, vinylene group, a propylene group, a 1, 3- cyclopentylene group, etc. are mention | raise | lifted. In addition, the divalent aromatic hydrocarbon group means a divalent monocyclic, condensed ring, and ring aggregated aromatic hydrocarbon group. For example, a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, p- Terphenyl-4,4 ″ -diyl group, m-terphenyl-3,3 ″ -diyl group, m-terphenyl-4,4′-diyl group, [1,2′-binaphthalene] -4, Examples thereof include divalent aromatic hydrocarbon groups having 6 to 30 carbon atoms such as a 5′-diyl group. Examples of the diarylamino group of R ^{a1 to} R ^a6 include N, N-diphenylamino group, N, N-ditolylamino group, N, N-bis (4-tert-butylphenyl) amino group, and N-phenyl-N. Examples thereof include diarylamino groups having 12 to 42 carbon atoms such as a -1-naphthylamino group, an N-phenyl-N-2-naphthylamino group, and an N-phenyl-N-9-phenanthrylamino group.

Moreover, the compound represented by the general formula [3] can also be suitably used as the hole injection layer of the present invention. In the general formula [3], R ^{a11 to} R ^a14 each independently represent a hydrogen atom, an alkoxyl group, or a cyano group. Here, the alkoxyl group includes a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. , Tert-butoxy group, octyloxy group, tert-octyloxy group, 2-bornyloxy group, 2-isobornyloxy group, 1-adamantyloxy group and the like. In particular, as a preferable combination of R ^{a11 to} R ^a14 of the general formula [3], it is preferable that all of R ^{a11 to} R ^a14 are a methoxy group, an ethoxy group, or a cyano group.

［式中、Z²¹は連結基であり、単結合、２価の脂肪族炭化水素基、２価の芳香族炭化水素基、酸素原子、硫黄原子のいずれかを表す。R^a21〜R^a26は、それぞれ独立に、１価の芳香族炭化水素基を表す。］
As a particularly preferable structure in the general formula [2], a compound represented by the following general formula [5-1] or general formula [5-2] can be given.
General formula [5-1]

[Wherein, Z ²¹ is a linking group, and represents a single bond, a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, an oxygen atom or a sulfur atom. R ^{a21 to} R ^a26 each independently represents a monovalent aromatic hydrocarbon group. ]

In the general formula [5-1], the linking group of Z ²¹ is a single bond, vinylene group, o-phenylene group, m-phenylene group, p-phenylene group, 1,4-naphthylene group, 2,6-naphthylene. Group, a 9,10-phenanthrylene group and a 9,10-anthrylene group are preferable, and a single bond, a vinylene group, a p-phenylene group and a 1,4-naphthylene group are more preferable. R ^{a21 to} R ^a26 include a monovalent aromatic hydrocarbon group selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. preferable.

［式中、Z³¹は連結基であり、単結合、２価の脂肪族炭化水素基、２価の芳香族炭化水素基、酸素原子、硫黄原子のいずれかを表す。R^a31〜R^a36は、それぞれ独立に、１価の芳香族炭化水素基を表す。］ General formula [5-2]

[Wherein, Z ³¹ is a linking group, and represents a single bond, a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, an oxygen atom or a sulfur atom. R ^{a31 to} R ^a36 each independently represents a monovalent aromatic hydrocarbon group. ]

In the general formula [5-2], the linking group for Z ³¹ is a single bond, vinylene group, o-phenylene group, m-phenylene group, p-phenylene group, 1,4-naphthylene group, 2,6-naphthylene. Group, 9,10-phenanthrylene group and 9,10-anthrylene group are preferable, and a single bond, vinylene group, p-phenylene group and 1,4-naphthylene group are more preferable. R ^{a31 to} R ^a36 include a monovalent aromatic hydrocarbon group selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. preferable.

［式中、R^a41〜R^a48は、それぞれ独立に、１価の芳香族炭化水素基を表す。］ In addition, in the general formula [2], other preferable structures include compounds represented by the following general formula [5-3] or general formula [5-4].
General formula [5-3]

[ ^Wherein , R ^{a41 to} R ^a48 each independently represents a monovalent aromatic hydrocarbon group. ]

In general formula [5-3], R ^{a41 to} R ^a48 are monovalent groups selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. The aromatic hydrocarbon group is preferred.

［式中、R^a51〜R^a56は、それぞれ独立に、１価の芳香族炭化水素基を表す。］ General formula [5-4]

[ ^Wherein , R ^{a51 to} R ^a56 each independently represents a monovalent aromatic hydrocarbon group. ]

In general formula [5-4], R ^{a51 to} R ^a56 are monovalent groups selected from a phenyl group, 1-naphthyl group, 2-naphthyl group, o-biphenylyl group, m-biphenylyl group, and p-biphenylyl group. The aromatic hydrocarbon group is preferred.

［式中、R^a61〜R^a64は、それぞれ独立に、１価の芳香族炭化水素基を表し、ｐは１〜４の整数を表す。］ Moreover, as another useful example, the compound represented by the following general formula [6] can also be used as the hole injection layer of the present invention.
General formula [6]

[ ^Wherein , R ^{a61 to} R ^a64 each independently represents a monovalent aromatic hydrocarbon group, and p represents an integer of 1 to 4. ]

In General Formula [6], R ^{a61 to} R ^a64 are monovalent aromatics selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. A group hydrocarbon group is preferred.

As specific examples of the hole injection material described above, the hole injection materials listed in Table 3 below can be used particularly preferably.

  On the other hand, for the electron injection layer, an electron injection material that exhibits an excellent electron injection effect with respect to the light emitting layer and that can form an electron injection layer excellent in adhesion to the cathode interface and thin film formability is used. Examples of such electron injection materials include metal complex compounds, nitrogen-containing five-membered ring derivatives, fluorenone derivatives, anthraquinodimethane derivatives, diphenoquinone derivatives, thiopyrandioxide derivatives, perylenetetracarboxylic acid derivatives, fluorenylidenemethane. Derivatives, anthrone derivatives, silole derivatives, triarylphosphine oxide derivatives, calcium acetylacetonate, sodium acetate and the like. In addition, inorganic / organic composite materials doped with metal such as cesium in bathophenanthroline (Proceedings of the Society of Polymer Science, Vol. 50, No. 4, 660, published in 2001), and the 50th Applied Physics Related Lecture Lecture Proceedings, No. Examples of electron injection materials include BCP, TPP, T5MPyTZ, etc. published on page 3, 1402, 2003. Electrons can be transported by forming a thin film necessary for device fabrication and injecting electrons from the cathode. If it is material, it will not specifically limit to these.

  Above as preferred among electron injecting material include metal complex compounds, nitrogen-containing five-membered ring derivatives, silole derivatives, triaryl phosphine oxide derivatives. As a preferable metal complex compound that can be used in the present invention, a metal complex of 8-hydroxyquinoline or a derivative thereof is suitable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include tris (8-hydroxyquinolinate) aluminum, tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (4-methyl-8- Hydroxyquinolinato) aluminum, tris (5-methyl-8-hydroxyquinolinato) aluminum, tris (5-phenyl-8-hydroxyquinolinato) aluminum, bis (8-hydroxyquinolinato) (1-naphtholate) ) Aluminum, bis (8-hydroxyquinolinate) (2-naphtholate) aluminum, bis (8-hydroxyquinolinate) (phenolate) aluminum, bis (8-hydroxyquinolinato) (4-cyano-1-naphtholate) ) Aluminum, bis (4-methyl-8) Hydroxyquinolinato) (1-naphtholato) aluminum, bis (5-methyl-8-hydroxyquinolinato) (2-naphtholato) aluminum, bis (5-phenyl-8-hydroxyquinolinato) (phenolate) aluminum, Bis (5-cyano-8-hydroxyquinolinate) (4-cyano-1-naphtholato) aluminum, bis (8-hydroxyquinolinato) chloroaluminum, bis (8-hydroxyquinolinato) (o-cresolate) Aluminum complex compounds such as aluminum, tris (8-hydroxyquinolinato) gallium, tris (2-methyl-8-hydroxyquinolinato) gallium, tris (4-methyl-8-hydroxyquinolinato) gallium, tris ( 5-Methyl-8-hydroxyquinolinate Gallium, tris (2-methyl-5-phenyl-8-hydroxyquinolinato) gallium, bis (2-methyl-8-hydroxyquinolinato) (1-naphtholato) gallium, bis (2-methyl-8-hydroxy) Quinolinate) (2-naphtholato) gallium, bis (2-methyl-8-hydroxyquinolinato) (phenolate) gallium, bis (2-methyl-8-hydroxyquinolinato) (4-cyano-1-naphtholate) ) Gallium, bis (2,4-dimethyl-8-hydroxyquinolinato) (1-naphtholate) gallium, bis (2,5-dimethyl-8-hydroxyquinolinato) (2-naphtholato) gallium, bis (2 -Methyl-5-phenyl-8-hydroxyquinolinate) (phenolate) gallium, bis (2-methyl-5- Cyano-8-hydroxyquinolinate) (4-cyano-1-naphtholate) gallium, bis (2-methyl-8-hydroxyquinolinate) chlorogallium, bis (2-methyl-8-hydroxyquinolinate) ( In addition to gallium complex compounds such as o-cresolate) gallium, 8-hydroxyquinolinate lithium, bis (8-hydroxyquinolinato) copper, bis (8-hydroxyquinolinato) manganese, bis (10-hydroxybenzo [h And quinolinato) beryllium, bis (8-hydroxyquinolinato) zinc, and bis (10-hydroxybenzo [h] quinolinato) zinc.

Among the electron injection materials that can be used in the present invention, preferable nitrogen-containing five-membered ring derivatives include oxazole derivatives, thiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, and triazole derivatives. , 5-bis (1-phenyl) -1,3,4-oxazole, 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1-phenyl) -1, 3,4-oxadiazole, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) 1,3,4-oxadiazole, 2,5-bis (1-naphthyl) -1 , 3,4-oxadiazole, 1,4-bis [2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2- (5-phenyloxadiazolyl) -4-tert-butyl benzene], -(4'-tert-butylphenyl) -5- (4 "-biphenyl) -1,3,4-thiadiazole, 2,5-bis (1-naphthyl) -1,3,4-thiadiazole, 1,4 -Bis [2- (5-phenylthiadiazolyl)] benzene, 2- (4'-tert-butylphenyl) -5- (4 "-biphenyl) -1,3,4-triazole, 2,5-bis (1-naphthyl) -1,3,4-triazole, 1,4-bis [2- (5-phenyltriazolyl)] benzene and the like.

［式中、Ar^r1およびAr^r2は、それぞれ独立に、置換基を有しても良い、１価の芳香族炭化水素基もしくは１価の含窒素芳香族複素環基を表す。］ Moreover, among the electron injection materials that can be used in the present invention, particularly preferable oxadiazole derivatives include oxadiazole derivatives represented by the following general formula [7].
General formula [7]

[ ^Wherein , Ar ^r1 and Ar ^r2 each independently represent a monovalent aromatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group which may have a substituent. ]

Examples of the monovalent nitrogen-containing aromatic heterocyclic group include 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 3-pyridyl group, 4-pyridazyl group, 2-pyrimidyl group, 4-pyrimidyl group, 5- Monovalent nitrogen-containing monocyclic aromatic heterocyclic group such as pyrimidyl group, 2-pyrazyl group, 1-imidazolyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl Group, 7-quinolyl group, 8-quinolyl group, 2-quinazolyl group, 4-quinazolyl group, 5-quinazolyl group, 2-quinoxalyl group, 5-quinoxalyl group, 6-quinoxalyl group, 1-indolyl group, 9-caribazolyl Monovalent nitrogen-containing fused ring aromatic heterocyclic group such as a group, 2,2′-bipyridyl-3-yl group, 2,2′-bipyridyl-4-yl group, 3,3′-bipyridyl-2-yl Group, 3,3′-bipyridyl And monovalent nitrogen-containing ring-assembled aromatic heterocyclic groups such as 4-yl group, 4,4′-bipyridyl-2-yl group, and 4,4′-bipyridyl-3-yl group. hydrogen atoms on the valence of the nitrogen-containing aromatic heterocyclic group may be substituted with a monovalent aliphatic hydrocarbon group or a monovalent aromatic hydrocarbon group.

In the general formula [7], as Ar ^r1 and Ar ^r2 , a preferable monovalent aromatic hydrocarbon group is substituted with a monovalent aliphatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group. 1-naphthyl group, 2-naphthyl group, o-biphenylyl group, m-biphenylyl group, and p-biphenylyl group are preferable, and preferable monovalent nitrogen-containing aromatic heterocyclic groups are monovalent A 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2,2′-bipyridyl-3-yl group, which may be substituted with an aliphatic hydrocarbon group or a monovalent aromatic hydrocarbon group, and A 2,2′-bipyridyl-4-yl group can be mentioned.

Table 4 shows specific examples of oxadiazole derivatives that can be used in the present invention.

［式中、Ar^t1〜Ar^t3は、それぞれ独立に、置換基を有しても良い、１価の芳香族炭化水素基もしくは１価の含窒素芳香族複素環基を表す。］ Among the electron injection materials that can be used in the present invention, a particularly preferred triazole derivative is a triazole derivative represented by the following general formula [8].
General formula [8]

[Wherein, Ar ^{t1 to} Ar ^t3 each independently represents a monovalent aromatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group which may have a substituent. ]

Here, as Ar ^t1 and Ar ^t2 , preferred monovalent aromatic hydrocarbon group is phenyl which may be substituted with a monovalent aliphatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group. Group, 1-naphthyl group, 2-naphthyl group, o-biphenylyl group, m-biphenylyl group, and p-biphenylyl group. Preferred monovalent nitrogen-containing aromatic heterocyclic groups include monovalent aliphatic groups. 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2,2′-bipyridyl-3-yl group, and 2 which may be substituted with an aromatic hydrocarbon group or a monovalent aromatic hydrocarbon group , 2'-bipyridyl-4-yl group. As Ar ^t3 , preferred monovalent aromatic hydrocarbon groups include a phenyl group, which may be substituted with a monovalent aliphatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group, Examples thereof include a naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. Preferred monovalent nitrogen-containing aromatic heterocyclic groups are monovalent aliphatic hydrocarbon groups. Or the 2-pyridyl group, 3-pyridyl group, and 4-pyridyl group which may be substituted by the monovalent | monohydric aromatic hydrocarbon group are mention | raise | lifted.

Table 5 shows specific examples of triazole derivatives that can be used in the present invention.

  Among the electron injection materials that can be used in the present invention, particularly preferred silole derivatives include silole derivatives represented by the following general formula [6].

［式中、R^p1およびR^p2は、それぞれ独立に、置換基を有しても良い、１価の脂肪族炭化水素基、１価の芳香族炭化水素基もしくは１価の含窒素芳香族複素環基を表す。Ar^p1〜Ar^p4は、それぞれ独立に、置換基を有しても良い、１価の芳香族炭化水素基もしくは１価の含窒素芳香族複素環基を表す。R^p1、R^p2、Ar^p1〜Ar^p4の隣接した基同士は互いに連結して環を形成しても良い。］ General formula [9]

[Wherein, R ^p1 and R ^p2 each independently represents a monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, or monovalent nitrogen-containing aromatic complex which may have a substituent. Represents a cyclic group. Ar ^{p1 to} Ar ^p4 each independently represents a monovalent aromatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group which may have a substituent. Adjacent groups of R ^p1 , R ^p2 and Ar ^{p1 to} Ar ^p4 may be connected to each other to form a ring. ]

Here, as R ^p1 and R ^p2 , preferred monovalent aliphatic hydrocarbon group is methyl which may be substituted with a monovalent aromatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group. Group, ethyl group, propyl group, and butyl group. Preferred monovalent aromatic hydrocarbon groups are substituted with a monovalent aliphatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group. And a phenyl group, an m-biphenylyl group, and a p-biphenylyl group. Preferred monovalent nitrogen-containing aromatic heterocyclic groups include a monovalent aliphatic hydrocarbon group or a monovalent aromatic carbon group. Examples thereof include a 2-pyridyl group, a 3-pyridyl group and a 4-pyridyl group, which may be substituted with a hydrogen group. In addition, as Ar ^{p1 to} Ar ^p4 , a preferable monovalent aromatic hydrocarbon group is a phenyl group which may be substituted with a monovalent aliphatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group. , 1-naphthyl group, 2-naphthyl group, o-biphenylyl group, m-biphenylyl group, and p-biphenylyl group, and preferable monovalent nitrogen-containing aromatic heterocyclic groups are monovalent aliphatic A 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2,2′-bipyridyl-3-yl group, which may be substituted with a hydrocarbon group or a monovalent aromatic hydrocarbon group, and 2, A 2'-bipyridyl-4-yl group is mentioned.

Table 6 shows specific examples of silole derivatives that can be used in the present invention.

［式中、Ar^q1〜Ar^q3は、それぞれ独立に、置換基を有しても良い１価の芳香族炭化水素基を表す。］ Of the electron injecting materials that can be used in the present invention, preferred triarylphosphine oxide derivatives include those disclosed in JP-A-2002-63989, JP-A-2004-95221, JP-A-2004-203828, and JP-A-2004. -204140 and the triarylphosphine oxide derivative represented by the following general formula [10] can be shown.
Formula [10]

[Wherein Ar ^{q1 to} Ar ^q3 each independently represents a monovalent aromatic hydrocarbon group which may have a substituent. ]

Here, as Ar ^{q1 to} Ar ^q3 , a preferable monovalent aromatic hydrocarbon group is a phenyl group which may be substituted with a monovalent aliphatic hydrocarbon group or a monovalent nitrogen-containing aromatic heterocyclic group. 1-naphthyl group, 2-naphthyl group, o-biphenylyl group, m-biphenylyl group, and p-biphenylyl group.

Table 7 shows specific examples of triarylphosphine oxide derivatives that can be used in the present invention.

  Next, for the hole blocking layer, a hole blocking material capable of preventing holes from passing through the light emitting layer from reaching the electron injection layer and forming a layer having excellent thin film forming properties is used. Examples of such hole blocking materials include aluminum complex compounds such as bis (8-hydroxyquinolinate) (4-phenylphenolate) aluminum, and bis (2-methyl-8-hydroxyquinolinate) ( 4-phenylphenolate) gallium complex compounds such as gallium, and nitrogen-containing condensed aromatic compounds such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

As the light emitting layer of the organic electroluminescence device of the present invention, those having the following functions are suitable.
Injection function; function transport function that can inject holes from the anode or hole injection layer when an electric field is applied, and electrons from the cathode or electron injection layer; electric field of injected charges (electrons and holes) Light emitting function: A function that provides a field for recombination of electrons and holes and connects it to light emission. However, there is a difference between the ease of hole injection and the ease of electron injection. In addition, the transport ability represented by the mobility of holes and electrons may be large or small, but it is preferable to move one of the charges. The light emitting material of the organic electroluminescence element is mainly an organic compound, and specifically, the following compounds are used depending on a desired color tone.

  For example, in the case of obtaining violet emission from the ultraviolet region, a compound represented by the following general formula [11] is preferably used.

General formula [11]

[Wherein, X1 represents a group represented by the following general formula [12], and X2 represents any one of a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. ]

（式中、ｍは２〜５の整数を示す） General formula [12]

(In the formula, m represents an integer of 2 to 5)

  The phenyl group, 1-naphthyl group, 2-naphthyl group, and phenylene group represented by X1 and X2 in the general formula [11] are one or more alkyl groups having 1 to 4 carbon atoms and 1 to 4 carbon atoms. It may be substituted with a substituent such as an alkoxyl group, a hydroxyl group, a sulfonyl group, a carbonyl group, an amino group, a dimethylamino group or a diphenylamino group. Moreover, when there are a plurality of these substituents, they may be bonded to each other to form a ring. Furthermore, the phenylene group represented by X1 is preferably bonded at the para position because it has good bonding properties and can easily form a smooth deposited film. Specific examples of the compound represented by the above general formula [11] are as follows (where Ph represents a phenyl group).

Among these compounds, p-quaterphenyl derivatives and p-quinkphenyl derivatives are particularly preferable.
Further, in order to obtain light emission in the visible range, particularly blue to green, for example, a fluorescent brightener such as benzothiazole, benzimidazole, and benzoxazole, a metal chelated oxinoid compound, and a styrylbenzene compound may be used. it can. Specific examples of these compounds include, for example, compounds disclosed in JP-A-59-194393. Still other useful compounds are listed in Chemistry of Synthetic Soybean (1971) pages 628-637 and 640.
As the metal chelated oxinoid compound, for example, compounds disclosed in JP-A-63-295695 can be used. As typical examples, 8-hydroxyquinoline-based metal complexes such as tris (8-quinolinol) aluminum, dilithium epinetridione and the like can be mentioned as suitable compounds.
As the styrylbenzene compound, for example, those disclosed in European Patent No. 0319881 and European Patent No. 0373582 can be used. And the distyrylpyrazine derivative currently disclosed by Unexamined-Japanese-Patent No. 2-252793 can also be used as a material of a light emitting layer. In addition, polyphenyl compounds disclosed in EP 0387715 can also be used as a material for the light emitting layer.

  Further, in addition to the above-described fluorescent brightener, metal chelated oxinoid compound, styrylbenzene compound and the like, for example, 12-phthaloperinone (J. Appl. Phys., Vol. 27, L713 (1988)), 1,4- Diphenyl-1,3-butadiene, 1,1,4,4-tetraphenyl-1,3-butadiene (Appl. Phys. Lett., Vol. 56, L799 (1990)), naphthalimide derivatives No. 2-305886), perylene derivatives (Japanese Patent Laid-Open No. 2-189890), oxadiazole derivatives (Japanese Patent Laid-Open No. Hei 2-216791, or the 38th Applied Physics Related Conference) were disclosed by Hamada et al. Oxadiazole derivatives), aldazine derivatives (JP-A-2-220393), pyrazirine derivatives (JP-A-2-220393) -20394), cyclopentadiene derivatives (JP-A-2-289675), pyrrolopyrrole derivatives (JP-A-2-29691), styrylamine derivatives (Appl. Phys. Lett., Vol. 56, L799 (1990). ), Coumarin compounds (JP-A-2-191694), international patent publications WO90 / 13148 and Appl. Phys. Lett., Vol 58, 18, P1982 (1991), 9 , 9 ′, 10,10′-tetraphenyl-2,2′-bianthracene, PPV (polyparaphenylene vinylene) derivatives, polyfluorene derivatives and copolymers thereof, for example, the following general formula [13] to general formula Having the structure of [15],

［式中、R^X1およびR^X2は、それぞれ独立に、１価の脂肪族炭化水素基を、ｎ１は、３〜１００の整数を表す。］ Formula [13]

[Wherein, R ^X1 and R ^X2 each independently represent a monovalent aliphatic hydrocarbon group, and n1 represents an integer of 3 to 100. ]

［式中、R^X3およびR^X4は、それぞれ独立に、１価の脂肪族炭化水素基を、ｎ２およびｎ３は、それぞれ独立に、３〜１００の整数を表す。］ General formula [14]

[Wherein, R ^X3 and R ^X4 each independently represent a monovalent aliphatic hydrocarbon group, and n2 and n3 each independently represent an integer of 3 to 100. ]

［式中、R^X5およびR^X6は、それぞれ独立に、１価の脂肪族炭化水素基を、ｎ４およびｎ５は、それぞれ独立に、３〜１００の整数を表す。Ｐｈはフェニル基を表す。］ General formula [15]

[Wherein, R ^X5 and R ^X6 each independently represent a monovalent aliphatic hydrocarbon group, and n4 and n5 each independently represent an integer of 3 to 100. Ph represents a phenyl group. ]

9,10-bis (N- (4- (2-phenylvinyl-1-yl) phenyl) -N-phenylamino) anthracene or the like can also be used as a material for the light emitting layer. Furthermore, a phenylanthracene derivative represented by the following general formula [16] as disclosed in JP-A-8-12600 can also be used as a light emitting material.
Formula [16]
A1-L-A2
[Wherein, A1 and A2 each independently represent a monophenylanthryl group or a diphenylanthryl group, which may be the same or different. L represents a single bond or a divalent linking group. ]
Here, the divalent linking group represented by L is preferably a divalent monocyclic or condensed ring aromatic hydrocarbon group which may have a substituent. In particular, phenylanthracene derivatives represented by the following general formulas [17] to [18] are preferable.

General formula [17]

[Wherein, R ^{Z1 to} R ^Z4 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a monovalent aromatic hydrocarbon group, an alkoxyl group, an aryloxy group, a diarylamino group, or a monovalent group. Represents an aliphatic heterocyclic group and a monovalent aromatic heterocyclic group, which may be the same or different. r1 to r4 each independently represents 0 or an integer of 1 to 5. When r1 to r4 are each independently an integer of 2 or more, R ^Z1 , R ^Z2 , R ^Z3 , R ^Z4 may be the same or different, and R ^Z1 , R ^Z2 together, R ^Z3 each other, R ^Z4 to each other may form a ring. L1 represents a divalent monocyclic or condensed ring aromatic hydrocarbon group which may have a single bond or a substituent, and a divalent monocyclic or condensed ring aromatic hydrocarbon group which may have a substituent May be an intervening alkylene group, —O—, —S— or —NR— (wherein R represents an alkyl group or an aryl group). ]

General formula [18]

[Wherein, R ^Z5 and R ^Z6 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a monovalent aromatic hydrocarbon group, an alkoxyl group, an aryloxy group, a diarylamino group, or a monovalent group. Represents an aliphatic heterocyclic group and a monovalent aromatic heterocyclic group, which may be the same or different. r5 and r6 each independently represents 0 or an integer of 1 to 5. When r5 and r6 are each independently an integer of 2 or more, R ^Z5 and R ^Z6 may be the same or different, and R ^Z5 and R ^Z6 are bonded to form a ring. May be. L2 represents a divalent monocyclic or condensed ring aromatic hydrocarbon group which may have a single bond or a substituent, and a divalent monocyclic or condensed ring aromatic hydrocarbon group which may have a substituent May be an intervening alkylene group, —O—, —S— or —NR— (wherein R represents an alkyl group or an aryl group). ]

  Of the general formula [17], phenylanthracene derivatives represented by the following general formula [19] to general formula [20] are more preferable.

General formula [19]

[Wherein, R ^{Z11 to} R ^Z30 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a monovalent aromatic hydrocarbon group, an alkoxyl group, an aryloxy group, a diarylamino group, a monovalent group. Represents an aliphatic heterocyclic group and a monovalent aromatic heterocyclic group, which may be the same or different. Further, R ^{Z11 to} R ^Z30 may be formed by connecting adjacent groups to form a ring. k1 represents an integer of 0 to 3. ]

General formula [20]

[Wherein, R ^{Z31 to} R ^Z50 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a monovalent aromatic hydrocarbon group, an alkoxyl group, an aryloxy group, a diarylamino group, or a monovalent group. Represents an aliphatic heterocyclic group and a monovalent aromatic heterocyclic group, which may be the same or different. In addition, R ^{Z31 to} R ^Z50 may be formed by connecting adjacent groups to form a ring. k2 represents an integer of 0 to 3. ]

Of the general formula [18], a phenylanthracene derivative represented by the following general formula [21] is more preferable.

Formula [21]

[Wherein, R ^{Z51 to} R ^Z60 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a monovalent aromatic hydrocarbon group, an alkoxyl group, an aryloxy group, a diarylamino group, a monovalent group. Represents an aliphatic heterocyclic group and a monovalent aromatic heterocyclic group, which may be the same or different. In addition, R ^{Z51 to} R ^Z60 may be formed by connecting adjacent groups to form a ring. k3 represents an integer of 0 to 3. ]

Specific examples of the general formula [19] to the general formula [21] include the following compounds.

Furthermore, the following compounds are also given as specific examples.

An amine compound represented by the following general formula [22] is also useful as a luminescent material.
General formula [22]

[In formula, h is a valence and represents the integer of 1-6. E1 represents an n-valent aromatic hydrocarbon group, and E2 represents an amino group selected from a dialkylamino group, a diarylamino group, and an alkylarylamino group. ]
Here, as a base structure of the n-valent aromatic hydrocarbon group represented by E1, naphthalene, anthracene, 9-phenylanthracene, 9,10-diphenylanthracene, naphthacene, pyrene, perylene, biphenyl, binaphthyl, and bianthryl are preferable. , E1 is preferably a diarylamino group. N is preferably 1 to 4, and most preferably 2. Of the general formula [22], amine compounds represented by the following general formula [23] to general formula [32] are particularly preferable.

General formula [23]

[Wherein, R ^{y1 to} R ^y8 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. Represents a cyclic group or an amino group selected from a dialkylamino group, a diarylamino group, and an alkylarylamino group, and at least one of R ^{y1 to} R ^y8 is a dialkylamino group, a diarylamino group, an alkylarylamino group. Represents an amino group selected from the group; R ^{y1 to} R ^y8 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [24]

[ ^Wherein , R ^{y11 to} R ^y20 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of R ^y11 to R ^y20, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y11 to} R ^y20 may be the same or different, and adjacent groups may be connected to form a ring. ]

Formula [25]

[ ^Wherein , R ^{y21 to} R ^y34 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, diarylamino group represents an amino group selected from alkyl aryl amino group, of R ^y21 to R ^Y34, at least one, dialkylamino groups, diarylamino groups, alkylarylamino Represents an amino group selected from the group; R ^{y21 to} R ^y34 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [26]

[ ^Wherein , R ^{y35 to} R ^y52 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of R ^y35 to R ^y52, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y35 to} R ^y52 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [27]

[ ^Wherein , R ^{y53 to} R ^y64 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of R ^y53 to R ^Y64, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y53 to} R ^y64 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [28]

[ ^Wherein R ^{y65 to} R ^y74 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of R ^Y65 to R ^Y74, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y65 to} R ^y74 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [29]

[ ^Wherein , R ^{y75 to} R ^y86 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of R ^Y75 to R ^Y86, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y75 to} R ^y86 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [30]

[ ^Wherein R ^{y87 to} R ^y96 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of ^R y87 ~R y96, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y87 to} R ^y96 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [31]

[ ^Wherein R ^{y97 to} R ^y110 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of R ^Y97 to R ^y110, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y97 to} R ^y110 may be the same or different, and adjacent groups may be connected to form a ring. ]

General formula [32]

[ ^Wherein R ^{y111 to} R ^y128 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, a monovalent aliphatic heterocyclic group, or a monovalent aromatic heterocyclic group. ring group, or a dialkylamino group, a diarylamino group, represents an amino group selected from alkyl aryl amino group, of ^R y111 ~R y128, at least one, dialkylamino group, diarylamino group, an alkylarylamino Represents an amino group selected from the group; R ^{y111 to} R ^y128 may be the same or different, and adjacent groups may be connected to form a ring. ]

  Specific examples of the amine compounds represented by the general formulas [23] to [32] described above include compounds having the following structures (where Ph represents a phenyl group).

  In the general formula [22] to general formula [32], a compound containing at least one styryl group represented by the following general formula [33] to general formula [34] instead of an amino group (for example, EP 0388768, JP-A-3-231970, etc.) can also be suitably used as the light emitting material.

［式中、Ｒ^y129〜Ｒ^y131は、それぞれ独立に、水素原子、アルキル基、シクロアルキル基、１価の芳香族炭化水素基を表す。Ｒ^y129〜Ｒ^y131は、隣り合う基同士が連結し、環を形成していても良い。］ Formula [33]

[ ^Wherein , R ^{y129 to} R ^y131 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or a monovalent aromatic hydrocarbon group. In R ^{y129 to} R ^y131 , adjacent groups may be connected to form a ring. ]

General formula [34]

[ ^Wherein , R ^{y132 to} R ^y138 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or a monovalent aromatic hydrocarbon group. R ^{y134 to} R ^y138 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a monovalent aromatic hydrocarbon group, or an amino group selected from a dialkylamino group, a diarylamino group, and an alkylarylamino group. As shown, at least one of R ^{y134 to} R ^y138 is an amino group selected from a dialkylamino group, a diarylamino group, and an alkylarylamino group. In R ^{y132 to} R ^y138 , adjacent groups may be connected to form a ring. ]

  Specific examples of the compound containing at least one styryl group represented by the general formulas [33] to [34] described above can include compounds having the following structure (where Ph represents a phenyl group): .

Further, the general formula (Rs-Q) _2- Al-O-L3 [wherein L3 is a hydrocarbon having 6 to 24 carbon atoms containing a phenyl moiety, as described in JP-A-5-258862, etc. O-L3 is a phenolate ligand, Q represents a substituted 8-quinolinolato ligand, Rs sterically represents that two or more substituted 8-quinolinolato ligands are bonded to an aluminum atom. And an 8-quinolinolate ring substituent selected so as to interfere.]. Specific examples include bis (2-methyl-8-quinolinolato) (para-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolato) (1-naphtholato) aluminum (III), and the like. .

  In addition, there is a method for obtaining a high-efficiency blue and green mixed light emission using doping described in JP-A-6-9953. In this case, examples of the host include the above-described light-emitting materials, and examples of the dopant include strong fluorescent dyes from blue to green, for example, coumarin-based or similar fluorescent dyes used as the above-described host. Specifically, a light-emitting material having a distyrylarylene skeleton as a host, particularly preferably 4,4′-bis (2,2-diphenylvinyl) biphenyl, and diphenylaminovinylarylene as a dopant, particularly preferably, for example, N, N-diphenyl Mention may be made of aminovinylbenzene.

Although there is no restriction | limiting in particular as a light emitting layer which obtains white light emission, The following can be used.
The energy level of each layer of the organic electroluminescence laminated structure is defined and light is emitted using tunnel injection (European Patent No. 0390551).
Similarly, a white light emitting element is described as an example of an element using tunnel injection (Japanese Patent Laid-Open No. 3-230584).
A light-emitting layer having a two-layer structure is described (JP-A-2-220390 and JP-A-2-216790).
A structure in which a light emitting layer is divided into a plurality of materials each having a different emission wavelength (Japanese Patent Laid-Open No. 4-51491).
A structure in which a blue phosphor (fluorescence peak 380 to 480 nm) and a green phosphor (480 to 580 nm) are stacked and a red phosphor is further contained (Japanese Patent Laid-Open No. 6-207170).
The blue light emitting layer contains a blue fluorescent dye, the green light emitting layer has a region containing a red fluorescent dye, and further contains a green phosphor (Japanese Patent Laid-Open No. 7-142169).
Among these, those having the above-described configuration are particularly preferable.

Furthermore, for example, the following known compounds are preferably used as the light emitting material (where Ph represents a phenyl group).

  In the organic electroluminescence device of the present invention, a phosphorescent material can be used. Examples of phosphorescent materials or doping materials that can be used in the organic electroluminescence device of the present invention include, for example, organometallic complexes, where the metal atom is usually a transition metal, and preferably has a fifth period or a sixth period. In terms of the period and group, elements from Group 6 to Group 11 and more preferably Group 8 to Group 10 are targeted. Specific examples include iridium and platinum. Examples of the ligand include 2-phenylpyridine and 2- (2′-benzothienyl) pyridine, and the carbon atom on these ligands is directly bonded to the metal. Another example is a porphyrin or tetraazaporphyrin ring complex, and the central metal is platinum. For example, the following known compounds are suitably used as the phosphorescent material (where Ph represents a phenyl group).

  Next, as a method for forming a light emitting layer using the above materials, for example, a known method such as a vapor deposition method, a spin coating method, or an LB method can be applied. The light emitting layer is particularly preferably a molecular deposited film. Here, the molecular deposited film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidifying from a material compound in a solution state or a liquid phase state. Can be classified from a thin film (accumulated film) formed by the LB method according to a difference in an agglomerated structure and a higher-order structure and a functional difference resulting therefrom. Further, as disclosed in JP-A-57-51781, a binder such as a resin and a material compound are dissolved in a solvent to form a solution, which is then thinned by a spin coat method or the like. A light emitting layer can be formed.

There is no restriction | limiting in particular about the film thickness of the light emitting layer formed in this way, Although it can select suitably according to a condition, Usually, the range of 5 nm-5 micrometers is preferable. This light emitting layer may be composed of a single layer made of one or more of the materials described above, or may be a laminate of a light emitting layer made of a compound different from the above light emitting layer.

  In the light emitting layer of the organic electroluminescence device, in addition to the light emitting material, if necessary, a host material, a doping material, a hole transport material, an electron transport material, and an electron injection material can be used in combination. . Further, the hole injection layer, the light emitting layer, and the electron injection layer may each be formed with a layer configuration of two or more layers.

Furthermore, the material used for the anode of the organic electroluminescence device of the present invention is preferably a material having a work function (4 eV or more) metal, alloy, electrically conductive compound or a mixture thereof as an electrode material. Specific examples of such an electrode substance include metals such as Au, Ag, Al, and Cr, and conductive materials such as CuI, ITO (Indium tin oxide), SnO ₂ , and ZnO. In order to form this anode, a thin film can be formed from these electrode materials by a method such as vapor deposition or sputtering. The anode desirably has such a characteristic that when light emitted from the light emitting layer is extracted from the anode, the transmittance of the anode for light emission is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. Further, although the film thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

  The material used for the cathode of the organic electroluminescence device of the present invention is a material having a work function (4 eV or less) metal, alloy, electrically conductive compound and a mixture thereof as an electrode material. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / silver alloy, aluminum / aluminum oxide, aluminum / lithium alloy, indium, and rare earth metals. The cathode can be formed by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. Here, when light emitted from the light-emitting layer is extracted from the cathode, the transmittance of the cathode for light emission is preferably greater than 10%. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

  Regarding the method for producing the organic electroluminescent device of the present invention, an anode, a hole injection layer, a hole transport layer, a light emitting layer, and an electron injection layer as necessary are formed by the above materials and methods, and finally a cathode. May be formed. Moreover, an organic electroluminescent element can also be produced from the cathode to the anode in the reverse order.

  This organic electroluminescence element is manufactured on a translucent substrate. This light-transmitting substrate is a substrate that supports the organic electroluminescence element. Regarding the light-transmitting property, it is desirable that the transmittance at 400 to 700 nm is 50% or more, preferably 90% or more. It is preferable to use a substrate.

  These substrates have mechanical and thermal strengths and are not particularly limited as long as they are transparent. For example, glass plates, synthetic resin plates and the like are preferably used. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the synthetic resin plate include plates such as polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, and polysulfone resin.

  In addition, as a method for forming each layer of the organic electroluminescence device of the present invention, a dry film forming method such as vacuum deposition, electron beam irradiation, sputtering, plasma, ion plating, or a wet method such as spin coating, dipping, flow coating, etc. Any method of film formation can be applied. The film thickness of each layer is not particularly limited, but if the film thickness is too thick, a large applied voltage is required to obtain a constant light output, resulting in poor efficiency. Conversely, if the film thickness is too thin, pinholes, etc. And it becomes difficult to obtain sufficient light emission luminance even when an electric field is applied. Accordingly, the thickness of each layer is suitably in the range of 1 nm to 1 μm, but more preferably in the range of 10 nm to 0.2 μm.

  Further, in order to improve the stability of the organic electroluminescence element against temperature, humidity, atmosphere, etc., a protective layer may be provided on the surface of the element, or the entire element may be covered or sealed with a resin or the like. In particular, when the entire element is covered or sealed, a photocurable resin that is cured by light is preferably used.

  The hole transport layer forming material used in the present invention is 50 ° C. or less (more preferably 30 ° C. or less) and a humidity of 80% or less (more preferably 60% or less) in a sealed container shielded from the outside air under light shielding. It is desirable to be stored in the environment.

  The current applied to the organic electroluminescence element of the present invention is usually a direct current, but a pulse current or an alternating current may be used. The current value and the voltage value are not particularly limited as long as the element is within a range not destroying the element. However, considering the power consumption and life of the element, it is desirable to efficiently emit light with as little electrical energy as possible.

  The organic electroluminescence device of the present invention can be driven not only by the passive matrix method but also by the active matrix method. The organic electroluminescence device of the present invention can be applied not only to a method called bottom emission in which light is extracted from the anode side but also to a method called top emission to extract light from the cathode side. These methods and techniques are described in Shinji Kido, “All about organic EL”, published by Nihon Jitsugyo Shuppansha (published in 2003).

  The organic electroluminescence element of the present invention may adopt a microcavity structure. This is an organic electroluminescence element having a structure in which a light emitting layer is sandwiched between an anode and a cathode, and the emitted light causes multiple interference between the anode and the cathode, but the reflectance of the anode and the cathode, A technology that actively utilizes the multiple interference effect and controls the emission wavelength extracted from the device by appropriately selecting the optical characteristics such as transmittance and the film thickness of the organic layer sandwiched between them. is there. Thereby, it is also possible to improve the emission chromaticity. For the mechanism of this multiple interference effect, see J.A. Yamada et al., AM-LCD Digest of Technical Papers, OD-2, p. 77-80 (2002).

  As described above, the organic electroluminescence device of the present invention exhibits high heat resistance and a long life. Therefore, it can be suitably used as a flat panel display such as a wall-mounted TV or a flat light emitter, and can be applied to light sources such as copiers and printers, light sources such as liquid crystal displays and instruments, display boards, marker lamps, and lighting. Is possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the following Example at all. First, prior to examples, a synthesis example of a hole transport layer forming material used in the present invention will be described.

Synthesis example 1
Synthesis and purification method of Compound 1 N, N′-diphenylphenanthrene-9,10-diamine 3.6 g, 4-bromo-N, N-diphenylaniline 9.7 g, palladium acetate, 0.074 g, tri-t-butyl 0.22 g of phosphine and 100 ml of xylene were mixed and heated to reflux for 2 hours under a nitrogen atmosphere. The reaction product was filtered at 80 ° C., and 800 mL of methanol was added to the filtrate. The precipitated solid was purified by column chromatography (silica gel, toluene) to obtain 4.2 g of a pale yellow powder. Next, 1.0 g of this pale yellow powder was sublimated at a temperature of 330 to 350 ° C. and a pressure of 2 to 4 × 10 ⁻³ Pa to obtain 0.82 g of Compound 1. Compound 1 has a glass transition temperature of 153 ° C. (according to DSC measurement), an Ip value of 5.4 eV (measurement using AC-1 manufactured by Riken Keiki Co., Ltd.), a maximum absorption wavelength of 324 nm (in toluene), a maximum The emission wavelength was 495 nm (in toluene).

Examples of the present invention are shown below. In Examples and Comparative Examples, known compounds shown in Table 8 and Table 9 below were used in addition to the compounds listed in Tables 1 to 7. Unless otherwise noted, all mixing ratios are weight ratios. In the production of the organic electroluminescence element, the vapor deposition was performed in a vacuum of 10 ⁻⁶ Torr without controlling the substrate temperature. In addition, the characteristics of the element are measured with an electrode area of 2 mm × 2 mm, and the half life is 5000 hours at 25 ° C. using an element sealed in a nitrogen atmosphere having an oxygen concentration and a water concentration of 1 ppm or less. Measurements were made to the limit.

Table 8

Table 9

Example 1
On a cleaned glass plate with an ITO electrode, a poly (2,3-dihydrothieno-1,4-dioxin) / poly (styrenesulfonate) aqueous solution (Sigma Aldrich Japan Co., Ltd., product number 48,309-5), PEDOT / PSS 1.3% aqueous solution) was formed into a film thickness of 50 nm by a spin coat method, and vacuum dried at 100 ° C. to form a hole injection layer. Next, a hole transport layer having a thickness of 80 nm was formed on the formed hole injection layer by spin coating with a solution in which compound 6 was dissolved in 1,2-dichloroethane. Next, a tris (8-hydroxyquinolinate) aluminum complex (Alq3) is deposited to form an electron injecting light emitting layer having a thickness of 30 nm, and an alloy in which magnesium and silver are mixed at a ratio of 10: 1. An electrode having a thickness of 100 nm was formed to obtain an organic electroluminescence element. The light emission efficiency of this device at a DC voltage of 10 V was 2.2 (lm / W). In addition, the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 2
A compound HIM4 was deposited on a glass plate with an ITO electrode to form a 60 nm-thick hole injection layer, and then compound 1 was deposited to form a 20-nm-thick hole transport layer. Next, Alq3 was vapor-deposited to form an electron-injecting light-emitting layer having a thickness of 60 nm, and an electrode was formed thereon by vacuum vapor deposition of 1 nm of lithium fluoride and 200 nm of aluminum to obtain an organic electroluminescence device. . When this element was driven at a current density of 10 (mA / cm ² ), the voltage was 5.0 (V), the luminance was 300 (cd / m ² ), and the luminous efficiency was 2.0 (lm / W). . In addition, when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ), the half-life was 5000 hours or more. Next, the same device was prepared and stored in an oven at 100 ° C. for 1 hour. Similarly, when the device characteristics were measured at a current density of 10 (mA / cm ² ) at room temperature, the voltage was measured. Was 5.0 (V), the luminance was 290 (cd / m ² ), and the light emission efficiency was 2.0 (lm / W). Furthermore, when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ), the half-life was 5000 hours or more.

Comparative Examples 1 to 4
An experiment similar to that of Example 2 was performed using Compound RH1 to Compound RH4 as the hole transport layer instead of Compound 1 used in Example 2. The results are shown in Table 10 together with Example 2.

  From the results shown in Table 10, the device prepared using Compound 1 of the present invention has a voltage, luminance, and half-life driven at the same current density as compared with the devices prepared using Compound RH1 to Compound RH4. It is clear that it is excellent.

Examples 3 to 25
An experiment was performed under the same conditions as in Example 2 using Compound 2 to Compound 24 as the hole transport layer instead of Compound 1 used in Example 2. The characteristics of the element were measured in the same manner as in Example 2 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, the device characteristics when all devices are driven at a current density of 10 (mA / cm ² ) are voltage 5.0 (V) or less, luminance is 290 (cd / m ² ) or more, and light emission The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more. Further, in the same manner as in Example 2, the same device was prepared and stored in an oven at 100 ° C. for 1 hour, and then halved when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ). The lifetime of each element was 5000 hours or more.

Example 26 to Example 40
Experiments were performed under the same conditions as in Example 26, using Compound HIM1 to Compound HIM3 and Compound HIM5 to Compound HIM16 as the hole injection layer instead of Compound HIM4 used in Example 2. The characteristics of the element were measured in the same manner as in Example 26 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, the device characteristics when all devices are driven at a current density of 10 (mA / cm ² ) are voltage 5.0 (V) or less, luminance is 300 (cd / m ² ) or more, and light emission The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 41
A compound HIM3 is deposited on a glass plate with an ITO electrode to form a 50 nm-thick hole injection layer, and then compound 2 and compound 3 are co-deposited at a composition ratio of 1: 1 to form a positive 30 nm-thick film. A hole transport layer was formed. Next, Compound B was deposited to form a light emitting layer having a thickness of 20 nm. Further, Alq3 was deposited to form an electron injection layer having a thickness of 20 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride and 150 nm of aluminum, to obtain an organic electroluminescence device. This device showed a luminous efficiency of 2.4 (lm / W) at a DC voltage of 5.2V. About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 42
A compound HIM5 is deposited on a glass plate with an ITO electrode to form a hole injection layer having a thickness of 60 nm, and then the compound 4 and the compound HTM9 are co-deposited at a composition ratio of 1: 1 to form a positive film having a thickness of 20 nm. A hole transport layer was formed. Next, Compound B was deposited to form a light emitting layer having a thickness of 20 nm. Further, Alq3 was deposited to form an electron injection layer having a thickness of 20 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride and 150 nm of aluminum, to obtain an organic electroluminescence device. This device showed a luminous efficiency of 2.2 (lm / W) at a DC voltage of 5.0V. About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 43
A compound HIM6 was deposited on a glass plate with an ITO electrode to form a 60 nm-thick hole injection layer, and then compound 4 was deposited to form a 15-nm-thick hole transport layer. Next, Compound C and Compound D were co-evaporated at a composition ratio of 20: 1 to form a light emitting layer having a thickness of 20 nm. Further, Alq3 was deposited to form an electron injection layer having a thickness of 20 nm. On top of that, an electrode was formed by vacuum vapor deposition of 1 nm of lithium fluoride and 200 nm of aluminum to obtain an organic electroluminescence element. This device showed a light emission efficiency of 5.7 (lm / W) at a DC voltage of 6.2 V. About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 44
A compound HIM7 was deposited on a glass plate with an ITO electrode to form a hole injection layer having a thickness of 55 nm, and then a compound 8 was deposited to form a hole transport layer having a thickness of 35 nm. Next, Compound E and Compound F were co-evaporated at a composition ratio of 20: 1 to form a light emitting layer having a thickness of 30 nm. Further, Alq3 was deposited to form an electron injection layer with a thickness of 30 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride and 180 nm of aluminum, to obtain an organic electroluminescence element. This device showed a luminous efficiency of 4.2 (lm / W) at a DC voltage of 4.2 V. About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 45
A compound HIM16 was deposited on a glass plate with an ITO electrode to form a 65-nm-thick hole injection layer, and then compound 10 was deposited to form a 15-nm-thick hole transport layer. Next, Compound G and Alq3 were co-evaporated at a composition ratio of 1: 1 to form an electron transporting light emitting layer having a thickness of 40 nm. Furthermore, an electrode having a thickness of 200 nm was formed from an alloy in which magnesium and silver were mixed at a ratio of 1: 3 to obtain an organic electroluminescence device. The light emission efficiency of this device at a DC voltage of 6.5 V was 2.3 (lm / W). About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 450 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 46
A compound HIM8 was vapor-deposited on a glass plate with an ITO electrode to form a hole injection layer having a thickness of 60 nm, and then a compound 11 was vapor-deposited to form a hole transport layer having a thickness of 20 nm. Next, Compound H and Compound J were co-evaporated at a composition ratio of 150: 1 to form a light emitting layer having a thickness of 25 nm. Further, BCP was deposited to form an electron injection layer having a thickness of 20 nm. On top of this, 0.5 nm of lithium and 150 nm of silver were vapor-deposited to obtain an organic electroluminescence element. This device showed a luminous efficiency of 1.1 (lm / W) at a DC voltage of 8.5V. About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 47
A compound HIM15 was vapor-deposited on a glass plate with an ITO electrode to form a hole injection layer having a thickness of 60 nm, and then a compound 13 was vapor-deposited to form a first hole transport layer having a thickness of 20 nm. Next, Compound K was deposited by 10 nm to form a second hole transport layer. Further, Compound L and Compound M were co-evaporated at a composition ratio of 1:10 to form a light emitting layer having a thickness of 25 nm. Further, BCP was deposited to form a 15 nm hole blocking layer. Further, Alq3 was deposited to form an electron injection layer having a thickness of 25 nm. On top of this, a cathode was formed by vapor deposition of 1 nm of lithium fluoride and 100 nm of aluminum to obtain an organic electroluminescence element. This device showed an external quantum efficiency of 8.2% at a DC voltage of 9.5V. About the element immediately after element preparation and after storing for 1 hour in an oven at 100 ° C., the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) is 5000 hours or more for all elements. there were.

Example 48
Compound HIM9 was deposited on a glass plate with an ITO electrode to form a 50 nm-thick hole injection layer, and then Compound 1 was deposited to 20 nm to form a hole transport layer. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. Further, Compound EX3 was deposited to form an electron injection layer having a thickness of 30 nm. On top of that, a cathode was formed by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic electroluminescence element. This device showed an emission luminance of 880 (cd / m ² ) at a DC voltage of 5.2 V. In addition, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. was 5000 hours for all elements. That was all.

Examples 49-71
The experiment was performed under the same conditions as in Example 48, using Compound 2 to Compound 24 as the hole transport layer instead of Compound 1 used in Example 48. The characteristics of the element were measured in the same manner as in Example 48 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 72-84
Instead of Compound EX3 used in Example 48, Compound EX4, Compound EX5, Compound EX7, Compound EX9, Compound EX10, Compound EX12 to Compound EX15, Compound EX17 to Compound EX20 were used as the electron injection layer. The experiment was performed under the same conditions. The characteristics of the element were measured in the same manner as in Example 48 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 85
A compound HIM10 was deposited on a glass plate with an ITO electrode to form a hole injection layer having a film thickness of 55 nm, and then a compound 1 was deposited to 20 nm to form a hole transport layer. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. Further, Compound ET3 was deposited to form an electron injection layer having a thickness of 30 nm. On top of that, a cathode was formed by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic electroluminescence element. This device showed an emission luminance of 850 (cd / m ² ) at a DC voltage of 5V. In addition, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. was 5000 hours for all elements. That was all.

Example 86 to Example 108
The experiment was performed under the same conditions as in Example 85, using Compound 2 to Compound 24 as the hole transport layer instead of Compound 1 used in Example 85. The characteristics of the element were measured in the same manner as in Example 85 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 109 to Example 121
Example 85 The experiment was performed under the same conditions. The characteristics of the element were measured in the same manner as in Example 85 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 122
Compound HIM11 was deposited on a glass plate with an ITO electrode to form a 60 nm-thick hole injection layer, and then Compound 1 was deposited to 15 nm to form a hole transport layer. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. Further, compound ES5 was deposited to form an electron injection layer having a thickness of 30 nm. On top of that, a cathode was formed by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic electroluminescence element. This device showed a luminous efficiency of 2.1 (lm / W) at a DC voltage of 5.0 V. In addition, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. was 5000 hours for all elements. That was all.

Example 123-Example 145
The experiment was performed under the same conditions as in Example 122 using Compound 2 to Compound 24 as the hole transport layer instead of Compound 1 used in Example 122. The characteristics of the element were measured in the same manner as in Example 122 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 146 to Example 154
Under the same conditions as in Example 122, using Compound ES2, Compound ES6, Compound ES8, Compound ES10 to Compound ES12, Compound ES14, Compound ES17, and Compound ES19 as the electron injection layer instead of Compound ES5 used in Example 122 The experiment was conducted. The characteristics of the element were measured in the same manner as in Example 122 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 155
A compound HIM12 was vapor-deposited on a glass plate with an ITO electrode to form a 65 nm-thick hole injection layer, and then compound 1 was vapor-deposited to form a 15-nm-thick hole transport layer. Next, Compound N and Compound P were co-evaporated at a composition ratio of 8: 100 to form a light emitting layer having a thickness of 35 nm. Further, Compound EP11 was deposited to form an electron injection layer having a thickness of 20 nm. On top of that, a cathode was formed by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic electroluminescence element. This device showed an external quantum efficiency of 7.6% at a DC voltage of 9V. In addition, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. was 5000 hours for all elements. That was all.

Examples 156 to 178
The experiment was performed under the same conditions as in Example 155 using Compound 2 to Compound 24 as the hole transport layer instead of Compound 1 used in Example 155. The characteristics of the element were measured in the same manner as in Example 155 for the element immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 179 to 188
In place of compound EP11 used in Example 155, compound EP3, compound EP4, compound EP8, compound EP10, compound EP12, compound EP17, compound EP18, compound EP19, compound EP21 and compound EP24 were used as the electron injection layer. The experiment was performed under the same conditions as in Example 155. The characteristics of the device were measured in the same manner as in Example 155 for the device immediately after device preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 189
A compound HIM4 was deposited on a glass plate with an ITO electrode to form a 60 nm-thick hole injection layer, and then compound 1 was deposited to form a 20-nm-thick hole transport layer. Next, Compound E and Compound F were co-evaporated at a composition ratio of 30: 1 to form a light emitting layer having a thickness of 20 nm. Further, Alq3 was deposited to form an electron injection layer having a thickness of 35 nm. On top of that, an electrode was formed by vacuum vapor deposition of 1 nm of lithium fluoride and 200 nm of aluminum to obtain an organic electroluminescence element. When the characteristics of this element were specified, the voltage required to obtain a light emission luminance of 100 (cd / m ² ) was 4.5 (V). Furthermore, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after the element was created and after being stored in an oven at 100 ° C. for 1 hour was 5000 hours for all elements. That was all.

Example 190-Example 193
A device was produced under the same conditions as in Example 189 except that the compounds listed in Table 11 below were used as the electron injection layer instead of Alq3 used in Example 189. Table 11 shows the element characteristics of the prepared element together with the results of Example 189 immediately after element preparation and after storage for 1 hour in an oven at 100 ° C.

From Table 11, it can be seen that the devices of Examples 190 to 193 can obtain the same luminance at a voltage lower than the device of Example 189 by 1.2 (V) or more. Furthermore, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after the element was created and after being stored in an oven at 100 ° C. for 1 hour was 5000 hours for all elements. As described above, it was revealed that both the driving voltage and the half life were excellent.

Claims (5)

An organic electroluminescence device having a multilayer organic layer including at least a light emitting layer, a hole transport layer, and a hole injection layer sandwiched between a pair of electrodes, wherein the hole transport layer has a glass transition temperature ( An organic electroluminescence device comprising a compound represented by the following general formula [1] wherein Tg) is 130 ° C. or higher.
General formula [1]

[Wherein, R ^{1 to} R ¹⁶ each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group, or a monovalent aromatic hydrocarbon group, and Ar ^{1 to} Ar ⁶ are each independently, Represents a monovalent aromatic hydrocarbon group. ] The organic electroluminescent device according to claim 1, wherein the hole injection layer comprises a compound represented by the following general formula [2] or general formula [3].
General formula [2]

[Wherein, Z ¹ is a linking group and represents a single bond, a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, an oxygen atom or a sulfur atom. R ^{a1 to} R ^a6 each independently represent a hydrogen atom, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, or a diarylamino group, and any one of R ^{a1 to} R ^a6 Is a diarylamino group. b1 and b2 represent an integer of 0 to 4, b3 to b6 represent an integer of 0 to 5, and b1 + b2 + b3 + b4 + b5 + b6 ≧ 1. ]
General formula [3]

[Wherein, R ^{a11 to} R ^a14 each independently represent a hydrogen atom, an alkoxyl group, or a cyano group, but they are not all simultaneously hydrogen atoms. ] Furthermore, an electron injection layer is provided between the cathode and the light emitting layer, and the electron injection layer includes at least one selected from an oxadiazole derivative, a triazole derivative, a silole derivative, and a triarylphosphine oxide derivative. The organic electroluminescence element according to claim 1 or 2, wherein All glass transition temperature of the material (Tg) of, claims 1 is 130 ° C. or higher to 3 organic electroluminescence device according to any one of forming the organic layer. A hole transport layer forming material of an organic electroluminescence device represented by the following general formula [4].
General formula [4]

[Wherein Ar ^{7 to} Ar ¹² are each independently a monovalent fragrance selected from a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, and a p-biphenylyl group. Represents a group hydrocarbon group. ]