JP2012248663A - Organic electroluminescent element material, organic electroluminescent element, display device, lighting device, and compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element material which has high luminous efficiency, a low driving voltage, and high durability with a small voltage increase during driving, and to provide an organic electroluminescent element using the same, a lighting device, a display device, and a compound constituting the organic electroluminescent element material.SOLUTION: An organic electroluminescent element material is a compound represented by general formula (1).

Description

  The present invention relates to an organic electroluminescence element material, and an organic electroluminescence element, a display device, a lighting device using the same, and a compound constituting the organic electroluminescence element material.

  Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (hereinafter referred to as ELD). Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements).

  Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements. On the other hand, an organic EL device has a structure in which a light-emitting layer containing a light-emitting compound is sandwiched between a cathode and an anode, and excitons (excitons) are generated by injecting electrons and holes into the light-emitting layer and recombining them. The device emits light by utilizing light emission (fluorescence / phosphorescence) when the exciton is deactivated. Organic EL elements can emit light at a voltage of several volts to several tens of volts, and are self-luminous, so they have a wide viewing angle, high visibility, and are thin-film, completely solid-state devices. It attracts attention from the viewpoint of space and portability.

However, for the future practical application of organic EL elements, it is desired to develop organic EL elements that can emit light efficiently and with high brightness with lower power consumption and that can reduce the voltage rise during driving. Yes.
Specifically, such a device is known in which a small amount of phosphor is doped into a stilbene derivative, a distyrylarylene derivative or a tristyrylarylene derivative to improve emission luminance and extend the lifetime of the device. . Moreover, the element which has an organic light emitting layer which doped 8-hydroxyquinoline aluminum complex as a host compound and a trace amount fluorescent substance to this, and the organic light emission which doped 8-quinoquinoline aluminum complex as a host compound and this to the quinacridone series pigment | dye Devices having layers are known.

  However, when light emission from excited singlet is used as described above, the generation ratio of singlet excitons and triplet excitons is 1: 3, so the generation probability of luminescent excited species is 25%. Since the extraction efficiency is about 20%, the limit of the external extraction quantum efficiency (η) is set to 5%. On the other hand, when the triplet is used, the upper limit of the internal quantum efficiency is 100%, so in principle the emission efficiency (external extraction quantum efficiency) is four times that of the excited singlet, which is almost equivalent to a cold cathode tube. It is attracting attention as a lighting application because there is a possibility that the above performance can be obtained.

For example, many heavy metal complexes, such as an iridium complex system, have been studied as dopants using excited triplets, and tris (2-phenylpyridine) iridium, L ₂ Ir (acac), (ppy) ₂ Ir (acac) are used as dopants. ), Tris (2- (p-tolyl) pyridine) iridium (Ir (ptpy) ₃ ), tris (benzo [h] quinoline) iridium (Ir (bzq) ₃ ), and the like have been studied (these) This metal complex is generally called an orthometalated iridium complex).

  In any of these cases, the light emission luminance and light emission efficiency of the light emitting device are greatly improved as compared with the conventional device because the emitted light is derived from phosphorescence. And as host compounds of these phosphorescent dopants, typified by 4,4′-bis (9-carbazolyl) biphenyl (CBP) and 1,3-bis (carbazol-9-yl) benzene (m-CP) The carbazole derivatives are well known. Further, m-CP and derivatives thereof are known as blue light emitting host compounds. However, even when these carbazole derivatives are used, the light emission efficiency and the lifetime have not been sufficiently satisfied (for example, see Patent Documents 1 and 2).

  On the other hand, host compounds having a phenoxazine skeleton and the like are also known (see, for example, Patent Document 3). Moreover, the compound which bridge | crosslinked carbazole with the carbon atom is known (for example, refer patent document 4, 5). By using these, although higher efficiency and improved durability can be achieved to some extent as compared with the carbazole derivatives described above, further improvements have been demanded. Furthermore, there has been a demand for an organic EL element with a low driving voltage and a small voltage increase during driving.

  Furthermore, a compound obtained by crosslinking a phenyl group of phenylcarbazole and a carbazole skeleton with two oxygen atoms is known as a polycyclic condensed ring compound (see, for example, Patent Document 6). However, there is no description that the performance of the organic EL device is further improved by performing crosslinking between the phenyl group and the carbazole skeleton using only one oxygen atom.

International Publication No. 03/80760 International Publication No. 04/74399 International Publication No. 07/015412 International Publication No. 10/050778 Special table 2008-511158 gazette International Publication No. 07/031165

  As described above, various compounds relating to the organic EL element material have been disclosed in the past, and the light emission efficiency is high at a low driving voltage, the durability (life) is excellent, and the voltage increase during driving can be reduced. An attempt has been made to develop an organic EL element that can be used. However, it is desired to develop an organic EL device that further improves these performances compared to the conventional one.

  The present invention has been made in view of the above circumstances, an organic electroluminescence element material having high luminous efficiency, low driving voltage, high durability, and small voltage increase during driving, and organic material using the same It is an object of the present invention to provide an electroluminescent element, a lighting device, a display device, and a compound constituting an organic electroluminescent element material.

The above object of the present invention can be achieved by adopting the following configuration.
1. An organic electroluminescent device material, which is a compound represented by the following general formula (1).

〔式中、Ｘ_１はＮ、Ｐ、Ｐ＝Ｏ、Ｐ＝Ｓ、ＳｉＡｒ_１のいずれかを表し、Ｙ_１はＮＡｒ_２、Ｏ、Ｓのいずれかを表す。Ａｒ_１及びＡｒ_２は芳香族炭化水素基又は芳香族複素環基を表す。Ａ_１〜Ａ_１１は各々独立にＣ−Ｒ_ｘ又はＮを表し、複数のＲ_ｘはそれぞれ同じであっても異なっていても良い。Ｒ_ｘは各々独立に、水素原子、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、芳香族炭化水素基、複素環基、芳香族複素環基、ハロゲン原子、アルコキシル基、シクロアルコキシル基、アリールオキシ基、アルキルチオ基、シクロアルキルチオ基、アリールチオ基、アルコキシカルボニル基、アリールオキシカルボニル基、スルファモイル基、ウレイド基、アシル基、アシルオキシ基、アミド基、カルバモイル基、スルフィニル基、アルキルスルホニル基、アリールスルホニル基、アミノ基、ニトロ基、シアノ基、ヒドロキシル基、アルキルシリル基、アリールシリル基、アルキルホスフィノ基、アリールホスフィノ基、アルキルホスホリル基、アリールホスホリル基、アルキルチオホスホリル基、アリールチオホスホリル基を表す。〕

[Wherein, X ₁ represents any _one of N, P, P═O, P═S, and SiAr ₁ , and Y ₁ represents any _one of NAr ₂ , O, and S. Ar ₁ and Ar ₂ represent an aromatic hydrocarbon group or an aromatic heterocyclic group. A _{1 to} A ₁₁ each independently represent C—R _x or N, and the plurality of R _x may be the same or different. R _x each independently represents a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxyl group, cycloalkoxyl group, aryl Oxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group , Amino group, nitro group, cyano group, hydroxyl group, alkylsilyl group, arylsilyl group, alkylphosphino group, arylphosphino group, alkylphosphoryl group, arylphosphoryl group, alkylthiophosphoryl group, arylthiophosphoryl Represents a group. ]

2. 2. The organic electroluminescent element material according to 1 above, wherein Y _{1 in the} general formula (1) is O.

3. 3. The organic electroluminescent element material as described in 2 above, wherein X _{1 in the} general formula (1) is N.

  4). An organic electroluminescence device comprising an organic layer sandwiched between at least one pair of an anode and a cathode, wherein the organic layer comprises at least one layer including a light emitting layer, and at least one of the organic layers is from 4. An organic electroluminescence device comprising the organic electroluminescence device material according to any one of 3 above.

  5). 5. The organic electroluminescent element according to 4 above, wherein the light emitting layer contains the organic electroluminescent element material according to any one of 1 to 3 above.

  6). 6. The organic electroluminescence device as described in 4 or 5 above, wherein the light emitting layer contains a phosphorescent dopant.

  7). 7. The organic electroluminescence device according to any one of 4 to 6, wherein the organic electroluminescence device is manufactured by a wet process.

  8). 8. A display device comprising the organic electroluminescence element according to any one of 4 to 7.

  9. 8. An illumination device comprising the organic electroluminescence element according to any one of 4 to 7.

  10. A compound represented by the following general formula (2):

〔式中、Ａ_１２〜Ａ_２２は各々独立にＣ−Ｒ_ｘ２又はＮを表し、複数のＲ_ｘ２はそれぞれ同じであっても異なっていても良い。Ｒ_ｘ２は各々独立に、水素原子、アルケニル基、芳香族炭化水素基、芳香族複素環基、ハロゲン原子、アルコキシル基、アリールオキシ基、アミノ基、アリールシリル基、アルキルホスホリル基、アリールホスホリル基を表す。〕

[Wherein, A _{12 to} A ₂₂ each independently represent C—R _{x 2} or N, and the plurality of R _{x 2} may be the same or different. Each R _x2 independently represents a hydrogen atom, an alkenyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, a halogen atom, an alkoxyl group, an aryloxy group, an amino group, an arylsilyl group, an alkylphosphoryl group, or an arylphosphoryl group; To express. ]

11. All said A < ₁₂ > -A < ₂₂ > is C-R _x2 , The compound of said 10 characterized by the above-mentioned.

  According to the present invention, it is possible to provide an organic electroluminescence element material having high luminous efficiency, low driving voltage, high durability, and small voltage increase during driving. Moreover, the organic electroluminescent element using this organic EL element material, an illuminating device, and a display apparatus can be provided. Moreover, the compound which comprises this organic EL element material can be provided.

It is a schematic diagram which shows an example of the display apparatus comprised from an organic EL element used in an Example. It is a schematic diagram which shows the display part of the display apparatus in FIG.

  Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to these.

<< Organic EL element material (Organic electroluminescence element material) >>
The organic EL element material of the present invention will be described.
The organic EL device material of the present invention is a compound represented by the following general formula (1).

〔式中、Ｘ_１はＮ、Ｐ、Ｐ＝Ｏ、Ｐ＝Ｓ、ＳｉＡｒ_１のいずれかを表し、Ｙ_１はＮＡｒ_２、Ｏ、Ｓのいずれかを表す。Ａｒ_１及びＡｒ_２は芳香族炭化水素基又は芳香族複素環基を表す。Ａ_１〜Ａ_１１は各々独立にＣ−Ｒ_ｘ又はＮを表し、複数のＲ_ｘはそれぞれ同じであっても異なっていても良い。Ｒ_ｘは各々独立に水素原子、又は、所定の置換基を表す。〕

[Wherein, X ₁ represents any _one of N, P, P═O, P═S, and SiAr ₁ , and Y ₁ represents any _one of NAr ₂ , O, and S. Ar ₁ and Ar ₂ represent an aromatic hydrocarbon group or an aromatic heterocyclic group. A _{1 to} A ₁₁ each independently represent C—R _x or N, and the plurality of R _x may be the same or different. R _x each independently represents a hydrogen atom or a predetermined substituent. ]

  First, after explaining the background and characteristics of the invention of the organic EL device material, the compound represented by the general formula (1) will be described in detail.

  Until now, a compound having a carbazole skeleton has been used as an electron transporting material or a host material. However, in an organic EL device using this compound, its luminous efficiency and durability have been problems. Here, a polycyclic compound obtained by crosslinking a phenyl group of phenylcarbazole and a carbazole skeleton using an oxygen atom or a carbon atom has been proposed so far. However, although the durability can be improved to some extent by using these, it is still insufficient in practical use. In this regard, the present inventors speculated that these polycyclic compounds were crosslinked with carbazole, so that the planarity of the crosslinked condensed ring structure was lowered and the desired durability could not be obtained.

  As a result of intensive studies in view of the above problems, the present inventors have achieved both high luminous efficiency and high durability by using a compound having a condensed ring structure represented by the general formula (1) of the present invention. I found out that I can. Furthermore, the driving voltage can be lowered and the voltage rise during driving can be reduced.

  Such an effect is manifested by the fact that the organic EL material of the present invention uses only one nitrogen atom, oxygen atom, or sulfur atom, as represented by the general formula (1), and a phenyl group and a carbazole skeleton. This is because of having a condensed ring structure with high planarity. As a result, it was possible to obtain a compound having improved stability against charge, excellent durability, and a small voltage increase during driving. Furthermore, by including heteroatoms such as N, O, and S, strong charge transportability was exhibited, and higher luminous efficiency could be realized at a low voltage. Thus, by including heteroatoms such as N, O, and S, the charge transport performance can be adjusted, and the optimum charge transport property of electrons and holes can be exhibited. It could be used as a material.

  In addition, when the organic EL element material of the present invention is used particularly in the light emitting layer, exciton generation and energy transfer to the dopant occur efficiently, so that recombination occurs efficiently and the organic EL material deteriorates. Was able to prevent. From the above, it is estimated that not only high efficiency and low voltage but also high durability can be achieved, and further, voltage increase during driving can be suppressed to a small level.

<< Compound Represented by Formula (1) >>
The compound represented by the general formula (1) will be described.
X ₁ in the general formula (1) represents any _one of N, P, P═O, P═S, and SiAr ₁ , and Y ₁ represents any _one of NAr ₂ , O, and S. Ar ₁ and Ar ₂ represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, and an aromatic hydrocarbon group is particularly preferred.

_One form of X ₁ is that X ₁ is N. When X ₁ is N, the hole charge transporting / injecting properties are further improved. _One of the forms of Y ₁ when X ₁ is N is that Y ₁ is NAr ₂ . In this case, the hole transportability is particularly improved, so that the light emission efficiency is improved.

Further, as _one of the forms of Y ₁ when X ₁ is N, Y ₁ is O or S. When Y ₁ is O or S, the charge transport property / injection property of electrons is further improved. Therefore, by having both charge transport properties of holes and electrons, high efficiency can be achieved. In addition, since the planarity of the condensed ring structure is increased, durability is improved, which is preferable. In particular, when X ₁ is N and Y ₁ is O, a particularly high durability can be achieved by having higher planarity, and therefore, it is mentioned as the most preferable mode.

Further, as _one of the forms of X ₁ , X ₁ can be P, P═O, P═S, or SiAr ₁ . X ₁ in that it contains a phosphorus atom or a silicon atom, by atoms of phosphorus atom or silicon atom radius is large, it is possible to maintain the planarity of the molecule, leading to improvement in durability. Here, among P, P = O, P = S, and SiAr ₁ , X ₁ is preferably any _one of P, P = O, and P = S. When X1 is any _one of P, P = O, and P = S, it is preferable because the light-emitting efficiency is improved by further improving the charge transport property and injection property of electrons. Further, P═O or P═S is more preferable, and P═O is particularly preferable.

_One of the forms of Y ₁ when X ₁ is any _one of P, P = O, and P = S is that Y ₁ is NAr ₂ . When Y ₁ is NAr ₂ , the hole transportability is improved, so that the light emission efficiency is improved by improving the charge transportability of both holes and electrons.

_One of the forms of Y ₁ when X ₁ is any _one of P, P = O, and P = S is that Y ₁ is O or S. When Y ₁ is O or S, the charge transporting property / injecting property of electrons is further improved, and therefore, high light emission efficiency can be achieved by exerting particularly strong electron charge transporting property. Further, when Y ₁ is O or S, the planarity of the condensed ring structure is increased, and thus durability is improved, which is preferable. In particular, when Y ₁ is O, planarity is further improved and durability is improved. Therefore, it is more preferable that Y ₁ is O.

Furthermore, _one of the forms of X ₁ is that X ₁ is SiAr ₁ . When X ₁ is SiAr ₁ , durability against electric charges is improved. _One form of Y ₁ when X ₁ is SiAr ₁ is that Y ₁ is NAr ₂ . In this case, the hole transport property is improved and the light emission efficiency is improved.

_One of the forms of Y ₁ when X ₁ is SiAr ₁ is that Y ₁ is O or S. When Y ₁ is O or S, the electron charge transporting / injecting property is further improved to improve the light emission efficiency, and the planarity of the condensed ring structure is improved, whereby the durability is improved. Further, when Y ₁ is O, the planarity is further improved and the durability is improved. Therefore, it is particularly preferable that Y ₁ is O.

Of the combinations of X ₁ and Y ₁ , the most preferable form when used as a host compound is that X ₁ is N and Y ₁ is O. That is, as described later, the compound is represented by the general formula (2) (however, as described later, the type of substituent represented by R _x is different). In this case, particularly high luminous efficiency and durability can be achieved.
When using the hole transport layer, if _{X 1} is N, and _{Y 1} is NAr _2, since it is possible to achieve the highest emission efficiency, _{X 1} is N, and _{Y 1} is a NAr ₂ It is preferable. Furthermore, when used for the electron transporting layer is, _{X 1} is P = O, and when _{Y 1} is O, since it achieved the highest emission efficiency, _{X 1} is P = O, and _{Y 1} is in O Preferably there is.

A _{1 to} A ₁₁ each independently represent C—R _x or N, and the plurality of R _x may be the same or different. When any one or more of A _{1 to} A ₁₁ is N, the charge transport property is improved, and a voltage increase during driving can be suppressed to a low level at a low voltage. Here, it is mentioned as a particularly preferable embodiment that one of A _{1 to} A ₁₁ is N. In particular, any of A _{5 to} A ₁₁ is preferably N, and among them, it is particularly preferable that any of A _{8 to} A ₁₁ is N. On the other hand, when A ₁ to A ₁₁ is a C-R _x, since it is possible to improve the durability, and the most preferred form. Therefore, in the general formula _{(1), A} 1 _{~A 11} is preferably either a _{C-R x.}

Several _Rx represents a hydrogen atom or a substituent each independently. If one or more _{R x} of the plurality of _{R x may} each independent represent a substituent independently is _preferably any one or more of A 5 _{to A 11} is a _{C-R x,} in particular _{A 6} Is preferably C—R _x .

Examples of the substituent represented by R _x include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, (t) butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group). Group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, propargyl group, etc.), aromatic hydrocarbon group ( Also referred to as aryl group, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group Etc.), heterocyclic groups (eg epoxy ring, aziridin ring, thii) Lan ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring Piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, Thiomorpholine-1,1-dioxide ring, pyranose ring, diazabicyclo [2,2,2] -octane ring, etc.), aromatic heterocyclic group (pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group) Re Group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzooxazolyl group , Thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group ( One of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced with a nitrogen atom), a quinoxalinyl group, a pyridazinyl group, a triazinyl group, a quinazolinyl group, a phthalazinyl group, etc.), a halogen atom (eg, a chlorine atom, a bromine group) Atoms, iodine atoms, fluorine atoms, etc.), alkoxy Group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxyl group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy Group (for example, phenoxy group, naphthyloxy group, etc.), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group) Cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyl) Oxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butyl) Aminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), ureido group (for example, methylureido group) Ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, Naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (eg, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (eg, Methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group Group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, Propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.) Sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexyl group) Silsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group or arylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, diarylamino group (for example, diphenylamino group, dinaphthylamino group, phenylnaphthylamino group, etc.), naphthylamino Group, 2-pyridylamino group, etc.), nitro group, cyano group, hydroxyl group, alkylsilyl group or arylsilyl group (for example, trimethylsilyl group, triethylsilyl group, (t) butyldimethylsilyl group, triisopropylsilyl group, (t ) Butyldiphenylsilyl group, triphenylsilyl group, trinaphthylsilyl group, 2-pyridylsilyl group, etc.), alkylphosphino group or arylphosphino group (dimethylphosphino group, diethylphosphino group, dicyclohexylphosphino group, methyl) Phenylphosphino group, diphenylphosphino group, dinaphthylphosphino group, di (2-pyridyl) phosphosphino group), alkylphosphoryl group or arylphosphoryl group (dimethylphosphoryl group, diethylphosphoryl group, dicyclohexylphosphoryl group, Ruphenylphosphoryl group, diphenylphosphoryl group, dinaphthylphosphoryl group, di (2-pyridyl) phosphoryl group), alkylthiophosphoryl group or arylthiophosphoryl group (dimethylthiophosphoryl group, diethylthiophosphoryl group, dicyclohexylthiophosphoryl group, methylphenyl) Thiophosphoryl group, diphenylthiophosphoryl group, dinaphthylthiophosphoryl group, di (2-pyridyl) thiophosphoryl group) and the like. These substituents may be further substituted by the above substituents, or they may be condensed with each other to form a ring.

If one or more R _x of the plurality of R _x represents a substituent, examples of R _x, aryl silyl group, an aryl phosphoryl group, an aromatic hydrocarbon group, aromatic heterocyclic group, a diarylamino group are preferable substituted It is mentioned as a group, and is particularly preferably a substituent containing a nitrogen atom. As the substituent containing a nitrogen atom, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group, a diarylamino group and the like are preferable, and a carbazolyl group or a carbolinyl group is particularly preferable.

<< Compound Represented by Formula (2) >>
The compound represented by the general formula (2) according to the present invention will be described.

A _{12 to} A ₂₂ in the general formula (2) each independently represent C—R _x2 or N, and the plurality of R _x2 may be the same or different. When any one or more of A _{12 to} A ₂₂ is N, the charge transport property is improved, and a voltage increase during driving can be suppressed to a low voltage. Here, it is mentioned as a particularly preferable embodiment that one of A _{12 to} A ₂₂ is N. In particular, any of A _{16 to} A ₂₂ is preferably N, and more preferably, any of A _{19 to} A ₂₂ is N.
On the other hand, when A _{12 to} A ₂₂ are C—R _{x 2} , the durability can be further improved, and therefore, it is mentioned as the most preferable mode. Therefore, in the general formula _{(2), A} 12 _{~A 22} is preferably either a _{C-R x2.}

Several _Rx2 represents a hydrogen atom or a substituent each independently. If each independently represent a plurality of one or more _{R x2} are each independently a substituent of _{R X2,} preferably more than one of A 16 _{to A 22} is _{C-R x2,} especially _{A 17} Is preferably C—R _x2 . As the substituent represented by R _x2 , among the substituents represented by R _x in the general formula (1), an alkenyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, a halogen atom, an alkoxyl group, A group having the same meaning as the aryloxy group, amino group, arylsilyl group, alkylphosphoryl group, and arylphosphoryl group is represented.

If one or more R _x2 of the plurality of R _x2 represent a substituent, examples of R _x2, aryl silyl group, an aryl phosphoryl group, an aromatic hydrocarbon group, aromatic heterocyclic group, a diarylamino group are preferable substituted It is a group, and a substituent containing a nitrogen atom is particularly preferable. As the substituent containing a nitrogen atom, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group, a diarylamino group and the like are preferable, and a carbazolyl group or a carbolinyl group is particularly preferable.

  Specific examples of the compound according to the present invention are shown below, but the compound according to the present invention is not limited thereto.

  Hereinafter, although an example of the synthesis | combination of the compound represented by General formula (1) is shown, as a synthesis | combination of a compound, it is not limited to these.

<< Synthesis Example; Synthesis of Exemplary Compound 1-35 >>
Exemplified compound 1-35 was synthesized by the following method.

(Synthesis of Intermediate 1)
Under a nitrogen stream, 20.0 g (109 mmol) of phenoxazine and 46.3 g (164 mmol) of 1-bromo-2-iodobenzene were put into the flask, and 1.39 g of copper powder and 16.6 g (120 mmol) of potassium carbonate were added thereto. In addition, it was heated at 200 ° C. for 8 hours. The reaction solution was cooled to room temperature, tetrahydrofuran was added, copper was filtered off, and the filtrate was concentrated under reduced pressure. The obtained crude product was recrystallized from dichloromethane to obtain 20.3 g of Intermediate 1 (yield 55%). The structure of Intermediate 1 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

(Synthesis of Intermediate 2)
Under a nitrogen stream, 16.5 g (48.9 mmol) of Intermediate 1, 1.1 g (4.89 mmol) of palladium acetate, 3.6 g (9.78 mmol) of tricyclohexylphosphonium tetrafluoroborate, 13.5 g of potassium carbonate ( 97.8 mmol) was put into a flask, 250 ml of dimethylacetamide was added thereto, and the mixture was heated to reflux for 3 hours. After cooling the reaction solution to room temperature, the solid was filtered off, water was added to the filtrate, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The obtained crude product was recrystallized from dichloromethane to obtain 8.4 g of intermediate 2 (yield 55%). The structure of Intermediate 2 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

Measurement conditions, chemical shift of each peak of the obtained spectrum, proton number, etc. are shown below.
¹ H-NMR (400 MHz, CDCl 3)
Measuring apparatus: JEOL JNM-AL400 (400 MHz): manufactured by JEOL Ltd. Spectrum attribution (chemical shift δ, peak shape, proton number)
6.71 (d, J = 7.8 Hz, 1H), 6.69-6.99 (m, 2H), 7.01-7.05 (m, 2H), 7.30 (t, J = 7 3 Hz, 1H), 7.43 (d, J = 7.3 Hz, 1H), 7.51 (dt, J = 7.8 Hz, 1.0 Hz, 1H), 7.65 (dd, J = 8. 1 Hz, 1.2 Hz, 1 H), 7.87 (d, J = 8.3 Hz, 1 H), 8.02 (dd, J = 7.6 Hz, 1.7 Hz, 1 H)

(Synthesis of Intermediate 3)
200 ml of a dichloromethane solution of 5 g (19.4 mmol) of Intermediate 2 was put into the flask, and 3.45 g (19.4 mmol) of N-bromosuccinimide was added in three portions under ice cooling. The reaction was returned to room temperature and diffused for 1 hour. The reaction solution was concentrated under reduced pressure, and the resulting crude product was purified by silica gel column chromatography to obtain 6.41 g of intermediate 3 (yield 98%). The structure was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

Measurement conditions, chemical shift of each peak of the obtained spectrum, proton number, etc. are shown below.
¹ H-NMR (400 MHz, CDCl 3)
Measuring apparatus: JEOL JNM-AL400 (400 MHz): manufactured by JEOL Ltd. Spectrum attribution (chemical shift δ, peak shape, proton number)
6.58 (dd, J = 8.3 Hz, 1.5 Hz, 1H), 6.96-6.98 (m, 2H), 7.01-7.07 (m, 1H), 7.15 (d , J = 8.3 Hz, 1H), 7.35 (t, J = 7.8 Hz, 1H), 7.56 (dt, J = 7.8 Hz, 1.5 Hz, 1H), 7.68 (d, J = 7.3 Hz, 1H), 7.89 (d, J = 8.8 Hz, 1H), 8.66 (d, J = 8.3H, 1H)

(Synthesis of Exemplified Compound 1-35)
Under a nitrogen stream, 2.0 g (5.94 mmol) of Intermediate 3, 1.25 g (2.98 mmol) of Intermediate 4 and 20 mL of ethylene glycol dimethyl ether were added into the flask, and 1.22 g (8.94 mmol) of potassium carbonate. 10 mL of an aqueous solution of was added. Further, 344 mg (0.594 mmol) of tetrakistriphenylphosphine palladium was added, and the mixture was heated to reflux for 12 hours. The reaction mixture was cooled to room temperature, tetrahydrofuran was added, the solid was filtered off, and the filtrate was concentrated under reduced pressure. The obtained crude product was recrystallized from tetrahydrofuran and further purified by preparative GPC to obtain 1.56 g (yield 78%) of Exemplary Compound 1-35. The structure of Exemplified Compound 1-35 was confirmed by nuclear magnetic resonance spectrum and mass spectrum. In addition, what further sublimated and refined this compound was used for preparation of the organic EL element mentioned later.

Measurement conditions, chemical shift of each peak of the obtained spectrum, proton number, etc. are shown below.
¹ H-NMR (400 MHz, CDCl 3)
Measuring apparatus: JEOL JNM-AL400 (400 MHz): manufactured by JEOL Ltd. Spectrum attribution (chemical shift δ, peak shape, proton number)
6.79 (d, J = 7.8 Hz, 2H), 6.96-7.01 (m, 6H), 7.03-7.08 (m, 4H), 7.45 (dt, J = 8 .1 Hz, 1.5 Hz, 2H), 7.63 (d, J = 7.8 Hz, 2H), 7.73 (dd, J = 8.1 Hz, 1.5 Hz, 2H), 7.75-7. 78 (m, 4H), 7.91 (d, J = 8.3 Hz, 2H), 8.17 (s, 2H)

<< Synthesis Example; Synthesis of Exemplary Compound 1-46 >>
Exemplary compound 1-46 was synthesized by the following method.

  Under a nitrogen stream, 213 mg (0.948 mmol) of palladium acetate and 2 ml of a 50% by mass xylene solution of tributylphosphine were added and stirred at room temperature for 30 minutes. Subsequently, 16 ml of dehydrated xylene, 2.0 g (4.74 mmol) of Intermediate 3, 0.84 g (4.96 mmol) of carbazole and 1.36 g (14.2 mmol) of sodium tert-butylate were added and heated to reflux for 4 hours. went. The reaction mixture was cooled to room temperature, tetrahydrofuran was added, the solid was filtered off, and the filtrate was concentrated under reduced pressure. The obtained crude product was recrystallized from tetrahydrofuran and further purified by preparative GPC to obtain 1.32 g (yield 66%) of Exemplary Compound 1-46. The structure of Example Compound 1-46 was confirmed by a nuclear magnetic resonance spectrum and a mass spectrum. In addition, what further sublimated and refined this compound was used for preparation of the organic EL element mentioned later.

Measurement conditions, chemical shift of each peak of the obtained spectrum, proton number, etc. are shown below.
¹ H-NMR (400 MHz, CDCl 3)
Measuring apparatus: JEOL JNM-AL400 (400 MHz): manufactured by JEOL Ltd. Spectrum attribution (chemical shift δ, peak shape, proton number)
6.51 (d, J = 8.3 Hz, 1H), 6.84 (t, J = 7.3 Hz, 1H), 6.91 (d, J = 8.3 Hz, 1H), 7.01-7 .12 (m, 3H), 7.16 (d, J = 8.3 Hz, 3H), 7.28-7.38 (m, 4H), 7.40 (dt, J = 8.3 Hz, 1. 5 Hz, 1 H), 7.74 (d, J = 8.3 Hz, 1 H), 7.89 (d, J = 8.8 Hz, 1 H), 8.23 (dd, J = 6.6 Hz, 1.2 Hz) , 2H)

<< Synthesis Example; Synthesis of Exemplary Compound 1-32 >>
Exemplified Compound 1-32 was synthesized by the following method.

(Synthesis of Intermediate 5)
Intermediate 5 was synthesized by applying the method described in J. Org. Chem., 1961, 26 (6), 2013-2017.

(Synthesis of Intermediate 6)
In a nitrogen stream, 150 g of a tetrahydrofuran solution of 20 g of Intermediate 5 (50 mmol) was cooled to −78 ° C., and then 62 ml of a hexane solution of n-butyllithium (1.65 mol / L) was slowly added dropwise and stirred for 1 hour. went. To this reaction solution, 150 ml of a tetrahydrofuran solution containing 10.6 g (50 mmol) of phenyltrichlorosilane was slowly added dropwise. After returning the reaction solution to room temperature, the mixture was heated to reflux for 3 hours. The solid was filtered off under nitrogen and the filtrate was concentrated under reduced pressure. The obtained crude product 14.6 g (76% yield) was used for the next reaction without further purification.

(Synthesis of Intermediate 7)
Under a nitrogen stream, 125 ml of a tetrahydrofuran solution of 13.7 g (38 mmol) of 2,4-dibromo-1-iodobenzene was cooled to −78 ° C., and then 24 ml of a hexane solution (1.65 mol / L) of n-butyllithium was slowly added. Was added dropwise and stirred for 1 hour. 125 ml of a tetrahydrofuran solution of 14.6 g (38 mmol) of intermediate 6 was slowly added dropwise to the reaction solution. After returning the reaction solution to room temperature, the mixture was heated to reflux for 3 hours. After cooling the reaction solution to room temperature, the solid was filtered off, water was added to the filtrate, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain 7.54 g of intermediate 7 (yield 34%). The structure of Intermediate 7 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

(Synthesis of Intermediate 8)
Under a nitrogen stream, 7.54 g (13 mmol) of Intermediate 7, 291 mg (1.3 mmol) of palladium acetate, 957 mg (2.6 mmol) of tricyclohexylphosphonium tetrafluoroborate, and 3.59 g (26 mmol) of potassium carbonate were placed in the flask. Then, 65 ml of dimethylacetamide was added thereto, followed by heating under reflux for 6 hours. After cooling the reaction solution to room temperature, the solid was filtered off, water was added to the filtrate, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain 4.77 g of intermediate 8 (yield 73%). The structure of intermediate 8 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

(Synthesis of Exemplified Compound 1-32)
Under a nitrogen stream, 32 ml of a tetrahydrofuran solution of 4.77 g of intermediate 8 (9.49 mmol) was cooled to −78 ° C., and then 6 ml of a hexane solution of n-butyllithium (1.65 mol / L) was slowly added dropwise. Stir for 1 hour. To this reaction solution, 32 ml of a tetrahydrofuran solution of 2.8 g (9.5 mmol) of triphenylchlorosilane was slowly added dropwise. After returning the reaction solution to room temperature, the mixture was heated to reflux for 2 hours. After cooling the reaction solution to room temperature, the solid was filtered off, water was added to the filtrate, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography and further purified by preparative GPC to obtain 5.0 g (yield 78%) of Exemplary Compound 1-32. The structure of Exemplified Compound 1-32 was confirmed by nuclear magnetic resonance spectrum and mass spectrum. In addition, what further sublimated and refined this compound was used for preparation of the organic EL element mentioned later.

<< Organic EL element (Organic electroluminescence element) >>
Next, the organic EL element of the present invention will be described.
The organic EL element of the present invention is an element containing an organic layer sandwiched between at least a pair of an anode and a cathode. And the said organic layer consists of at least 1 layer containing a light emitting layer, and at least 1 layer contains the organic EL element material of this invention demonstrated above among this organic layer.

  Note that “at least one layer including a light emitting layer” essentially includes a light emitting layer and may be one light emitting layer, or together with this light emitting layer, for example, a hole injection layer or a hole transport described below. It means that an organic layer such as a layer, a hole blocking layer, an electron transport layer, and an electron injection layer may be included. That is, it means an organic layer composed of one light emitting layer or a light emitting layer and one or more other organic layers.

<Structure layers of organic EL elements>
The constituent layers of the organic EL element of the present invention will be described. In the present invention, preferred specific examples of the layer structure of the organic EL element are shown below, but the present invention is not limited thereto.
(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (v) anode / hole transport layer / light emitting layer / electron transport layer / electron injection Layer / cathode (vi) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (vii) anode / hole injection layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / electron injection layer / cathode In addition to the hole blocking layer, an electron blocking layer can also be used as the blocking layer.

  In the present invention, each layer of the organic EL element may contain the compound represented by the general formula (1), and among them, any one or more of a hole transport layer, a light emitting layer, and an electron transport layer are included. It is preferable to contain in a layer, and it is more preferable to contain in a light emitting layer or an electron carrying layer. Furthermore, it is more preferable to contain the compound represented by the general formula (1) in the light emitting layer, and it is particularly preferable to contain the compound as a host compound.

  In the organic EL device of the present invention, the blue light emitting layer preferably has an emission maximum wavelength of 430 to 480 nm, the green light emitting layer has an emission maximum wavelength of 510 to 550 nm, and the red light emitting layer has an emission maximum wavelength of 600 to 640 nm. A monochromatic light emitting layer in the range is preferable, and a display device using these is preferable. Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL element of the present invention preferably emits white light and is preferably a lighting device using these.

Next, each layer which comprises the organic EL element of this invention is demonstrated.
[Light emitting layer]
The light emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer. The portion that emits light may be within the layer of the light emitting layer or at the interface between the light emitting layer and the adjacent layer.
The total thickness of the light emitting layer is not particularly limited, but it is 2 nm from the viewpoint of film uniformity, preventing application of an unnecessary high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust to the range of -5 micrometers, More preferably, it is the range of 2-200 nm, Most preferably, it is the range of 10-20 nm.
For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is formed and formed by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink-jet method. it can.

  The light emitting layer of the organic EL device of the present invention preferably contains a light emitting host compound and at least one kind of light emitting dopant (such as a phosphorescent dopant (also referred to as a phosphorescent dopant) or a fluorescent dopant).

(Host compound (also called luminescent host))
The host compound used in the present invention is not particularly limited in terms of structure, but is typically a carbazole derivative, a triarylamine derivative, an aromatic borane derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligo Those having a basic skeleton such as an arylene compound, or a carboline derivative or a diazacarbazole derivative (here, a diazacarbazole derivative is a nitrogen atom in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is a nitrogen atom) And the like.) And the like.

As the host compound, the above host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of the compound containing the partial structure represented by the said General formula (1), and the light emission dopant mentioned later, and can obtain arbitrary luminescent colors by this. it can.
The host compound used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (deposition polymerization property). Light emitting host).

As the known host compound that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable.
Specific examples of known host compounds include compounds described in the following documents.
JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

(Luminescent dopant)
As the light-emitting dopant, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used. Here, it is preferable that the light emitting layer which comprises the organic EL element of this invention contains a phosphorescence dopant. However, from the viewpoint of obtaining an organic EL device with higher luminous efficiency, the light emitting dopant (sometimes simply referred to as a light emitting material) used in the light emitting layer or the light emitting unit of the organic EL device of the present invention is the above general formula. It is preferable to contain the compound containing the partial structure represented by (1) as a phosphorescent dopant.

(Phosphorescent dopant)
A phosphorescent dopant is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.) and is defined as a compound having a phosphorescence quantum yield of 0.01 or more at 25 ° C., but a preferable phosphorescence quantum yield is 0. .1 or more.
The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvent, the phosphorescence dopant should just achieve the said phosphorescence quantum yield (0.01 or more) in any solvent.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. It is an energy transfer type to obtain light emission from a phosphorescent dopant. The other is a carrier trap type in which a phosphorescent dopant serves as a carrier trap, and carrier recombination occurs on the phosphorescent dopant to emit light from the phosphorescent dopant. In any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

The phosphorescent dopant is preferably a complex compound containing a group 8-10 metal in the periodic table, more preferably an iridium compound, an osmium compound, a platinum compound (platinum complex compound), or a rare earth complex. Among them, the most preferable is an iridium compound.
In this invention, a well-known phosphorescence dopant can be used as a phosphorescence dopant used for the light emitting layer of an organic EL element.
Although the specific example of the well-known compound used as a phosphorescence dopant below is shown, as a phosphorescence dopant, it is not limited to these. In addition, these compounds are described in Unexamined-Japanese-Patent No. 2010-98223. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

(Fluorescent dopant (also called fluorescent compound))
Fluorescent dopants (fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes Examples thereof include dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

[Electron transport layer]
The electron transport layer is a layer made of a material having a function of transporting electrons. The electron transport layer can be provided as a single layer or a plurality of layers.
In the case of a single-layer electron transport layer and a plurality of layers, as an electron transport material used for an electron transport layer adjacent to the cathode side with respect to the light emitting layer, a function of transmitting electrons injected from the cathode to the light emitting layer Use what has. As the material, the organic EL element material according to the present invention can be used as an electron transporting material to achieve the effects of the present invention. However, in addition, any one of conventionally known compounds can be selected and used in combination as long as the effect of the organic EL element material (that is, the electron transport material) according to the present invention is not impaired. Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be exemplified. Furthermore, the polymeric material which introduce | transduced these materials into the polymer chain, or made these materials into the polymeric principal chain can also be mentioned.

Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg, Cu , Ca, Sn, Ga or Pb can also be mentioned as metal complexes. In addition, metal-free or metal phthalocyanine, or those having a terminal substituted with an alkyl group or a sulfonic acid group can also be used. Moreover, inorganic semiconductors, such as a distyrylpyrazine derivative and n-type-Si and n-type-SiC, can also be mentioned.
The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

It can also be used as an electron transport layer having a high n property doped with impurities. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.
It is preferable to use such an n-type electron transport layer because an element with lower power consumption can be manufactured.

[Injection layer: electron injection layer, hole injection layer]
The injection layer is a layer provided as necessary, and includes an electron injection layer and a hole injection layer. The injection layer may be present between the anode and the hole transport layer or between the cathode and the electron transport layer as shown in the above layer configuration. Alternatively, it may exist between the anode and the light emitting layer or between the cathode and the light emitting layer.
An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.
The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

[Blocking layer: hole blocking layer, electron blocking layer]
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.
The hole blocking layer has a function of an electron transporting layer in a broad sense, and is made of a hole blocking material having a function of transporting electrons and an extremely small ability to transport holes. By blocking holes while transporting electrons, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer as needed.
In addition, it is preferable that the hole-blocking layer of the organic EL element of this invention is provided adjacent to the light emitting layer.

The hole blocking layer preferably contains the carbazole derivative, carboline derivative or diazacarbazole derivative mentioned as the host compound.
Further, in the present invention, when a plurality of light emitting layers having different emission colors are provided, the light emitting layer having the shortest wavelength of the light emission maximum wavelength (shortest wave layer) is closest to the anode among all the light emitting layers. preferable. In such a case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the shortest wave layer. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at this position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave layer.

The ionization potential is defined by the energy required to emit an electron at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.
(1) Keywords using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), which is molecular orbital calculation software manufactured by Gaussian, USA. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit converted value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.
(2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

[Hole transport layer]
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.
The hole transport material has any of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.
The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.
JP-A-11-251067, J. Org. Huang et al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.
The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials.

Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.
In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

[anode]
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually in the range of 10 to 1000 nm, preferably in the range of 10 to 200 nm.

[cathode]
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.
Moreover, after producing the metal with a film thickness of 1 to 20 nm on the cathode, a transparent or translucent cathode can be produced by producing the conductive transparent material mentioned in the description of the anode on the cathode, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

Next, matters other than the constituent layers related to the organic EL element will be described.
[Support substrate]
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

An inorganic film, an organic film, or a hybrid film of both may be formed on the surface of the resin film, and the water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. Permeability is 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less (1 atm is 1.01325 × 10 ⁵ Pa) Water vapor permeability is 10 ⁻³ g / (m ² · 24 h) or less Preferably, the water vapor permeability is 10 ⁻⁵ g / (m ² · 24 h) or less.

As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.
The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used. However, an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, ceramic substrates, and the like.
The external extraction efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.
In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

[Sealing]
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.
The sealing member should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient as it. Further, transparency and electrical insulation are not particularly limited.
Specifically, a glass plate, a polymer plate (film), a metal plate (film), etc. are mentioned. 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 polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned. Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the above method is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.
For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.
In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

In the gap between the sealing member and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.
Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

[Protective film, protective plate]
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

[Light extraction]
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be extracted outside the device, This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.
As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.
In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.
When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.
Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.
The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Light that cannot be emitted due to total internal reflection, etc. is diffracted by introducing a diffraction grating in any layer or medium (in the transparent substrate or transparent electrode), and the light is emitted outside. I want to take it out.

The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.
As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.

[Condenser sheet]
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.
As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, a substrate may be formed by forming a triangle (triangular) stripe with a vertex angle of 90 degrees and a pitch of 50 μm, a shape with a rounded vertex, and a pitch. The shape may be changed at random, or other shapes.
Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co. can be used.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.
First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, thereby producing an anode.
Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer, which are organic EL element materials, is formed thereon.
As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like. However, in the present invention, it is preferable to produce an organic EL element by a wet process. By producing it by a wet process, it is possible to obtain an effect such that a homogeneous film can be easily obtained and pinholes are hardly generated. Among these, film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is preferable. These coating methods have the advantage that they are highly efficient, simple and easy to increase in area, and according to the ink jet method, they have the advantage that they can be applied in units of pixels.

Examples of the liquid medium for dissolving or dispersing the organic EL device material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, Aromatic hydrocarbons such as mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.
After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm. By providing, a desired organic EL element can be obtained.
In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

《Display device, lighting device》
The display device or illumination device of the present invention comprises the above-described organic EL element of the present invention (specific examples of the display device and illumination device will be described in “Usage” described later). That is, an organic EL element material that is a compound represented by the general formula (1) is used.
Since the display device or lighting device of the present invention uses the organic EL element of the present invention, it can be driven at a low voltage, and the voltage rise during driving is small. In addition, since the light emission efficiency is high and the durability is excellent, the device can have a long lifetime.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Examples include, but are not limited to, the light source of the sensor. However, it can be effectively used particularly as a backlight of a liquid crystal display device and an illumination light source.

  In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.

The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.
When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

  Hereinafter, the present invention will be specifically described with reference to Examples 1 to 5, but the scope of the present invention is not limited thereto.

[Example 1]
<< Production of Organic EL Element 1-1 >>
An organic EL element was produced as follows.
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass) made of ITO (indium tin oxide) with a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes. This transparent support substrate is fixed to a substrate holder of a commercially available vacuum evaporation apparatus. Meanwhile, 200 mg of α-NPD is put into a molybdenum resistance heating boat, 200 mg of CBP is put into another resistance heating boat made of molybdenum, and another resistance made of molybdenum. 200 mg of bathocuproin (BCP) is put into a heating boat, and 100 mg of phosphorescent compound tris (2-phenylviridinate) iridium (III) (Ir (ppy) ₃ ) is put into another resistance heating boat made of molybdenum. 200 mg of tris (8-quinolinolato) aluminum (Alq ₃ ) was put in a resistance heating boat and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing α-NPD was energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / sec. The hole transport layer was provided. Further, the heating boat containing CBP and the phosphorescent compound Ir (ppy) ₃ was energized and heated, and co-deposited on the hole transport layer at a deposition rate of 0.2 nm / sec and 0.012 nm / sec, respectively. A light emitting layer having a thickness of 35 nm was provided. In addition, the substrate temperature at the time of vapor deposition was room temperature. Further, an electron transport layer that also serves as a hole blocking function with a film thickness of 10 nm is provided by energizing and heating the heating boat containing BCP and depositing on the light emitting layer at a deposition rate of 0.1 nm / sec. It was. On top of that, the heating boat containing Alq ₃ was further energized and heated, and was deposited on the electron transport layer at a deposition rate of 0.1 nm / sec to provide an electron injection layer having a thickness of 40 nm. . In addition, the substrate temperature at the time of vapor deposition was room temperature.
Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-18 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-18 were produced in the same manner except that the CBP of the light emitting layer as shown in Table 1 was replaced with the compound shown in Table 1.

The structural formulas of BCP, Alq ₃ , Ir (ppy) ₃ , α-NPD, and CBP used in this example are shown below.

また、比較化合物としては下記のものを用いた。

The following compounds were used as comparative compounds.

<< Evaluation of organic EL elements >>
The produced organic EL element was evaluated as follows, and the results are shown in Table 1.
(Luminescence efficiency)
In the organic EL element 1-1, current started to flow at an initial driving voltage of 3 V, and green light was emitted from the phosphorescent compound that was the dopant of the light emitting layer. About the produced organic EL element, luminous efficiency (lm / W) when a 10 V DC voltage was applied under a dry nitrogen gas atmosphere at room temperature (about 23 to 25 ° C.) was measured. The luminous efficiency was expressed as a relative value when the organic EL element 1-1 was 100.

(durability)
The half-life time, which is the time required for the initial luminance to drop to half of the original luminance when driven at a constant current of ^2.5 mA / cm ² at room temperature, was expressed as an index. The half-life time was expressed as a relative value when the organic EL element 1-1 was taken as 100.

(Drive voltage)
Each voltage was measured when the organic EL element was driven at room temperature and under a constant current condition of ^2.5 mA / cm ² , and the measurement results are as follows. Indicated by value.
Drive voltage = (initial drive voltage of each element / initial drive voltage of the organic EL element 1-1) × 100
In addition, it shows that a drive voltage is small with respect to a comparison, so that a value is small.

(Change in drive voltage over time)
The organic EL device was continuously lit under a constant current condition of ^2.5 mA / cm ² at room temperature, and the driving voltage when the luminance reached 70% of the initial luminance was measured. The measurement results are shown as relative values so that the organic EL element 1-1 (comparison) becomes 100 as shown below.
Drive voltage change 1 = (drive voltage when the luminance of the organic EL element 1-1 is 70%) / (initial drive voltage of the organic EL element 1-1)
Change in drive voltage of each element = (drive voltage at 70% luminance of each element) / (initial drive voltage of each element)
Drive voltage change (τ ^1/7 ) = (Drive voltage change of each element) / (Drive voltage change 1) × 100

  From Table 1, it can be seen that the organic EL device of the present invention is excellent in luminous efficiency, high in durability and long in life, and is an excellent organic EL device. Further, it can be seen that the drive voltage is lowered and the voltage rise during driving is suppressed. Moreover, it turns out that higher luminous efficiency and lifetime can be made compatible by making the organic EL element material which concerns on this invention into a more preferable aspect (for example, a preferable substituent, the number of this substituent, etc.). It can also be seen that the drive voltage can be lowered and the voltage rise during driving can be reduced.

[Example 2]
<< Production of Organic EL Elements 2-1 to 2-18 >>
Organic EL device 1 except that phosphorescent compound Ir (ppy) ₃ of organic EL device 1-1 of Example 1 was replaced with compound Ir-15 shown in [Chemical Formula 14] described above and CBP was replaced with the compounds shown in Table 2. Organic EL elements 2-1 to 2-18 were produced in exactly the same manner as the production of -1. About these elements which show blue light emission, the light emission efficiency, durability, and drive voltage were measured by the same method as Example 1. The obtained results are shown in Table 2.

  From Table 2, it can be seen that the blue light-emitting organic EL device of the present invention is an excellent blue light-emitting organic EL device having excellent luminous efficiency, high durability and long life. Further, it can be seen that the drive voltage is lowered and the voltage rise during driving is suppressed. Moreover, it turns out that higher luminous efficiency and lifetime can be made compatible by making the organic EL element material which concerns on this invention into a more preferable aspect (for example, a preferable substituent, the number of this substituent, etc.). It can also be seen that the drive voltage can be lowered and the voltage rise during driving can be reduced.

[Example 3]
<< Production of Organic EL Elements 3-1 to 3-35 >>
Organic EL elements 3-1 to 3-35 were produced in exactly the same manner except that the hole transport layer and the electron transport layer of the organic EL element 1-1 of Example 1 were replaced with the compounds shown in Table 3. About these elements which show green light emission, the light emission efficiency, durability, and the drive voltage were measured by the method similar to Example 1. FIG. The obtained results are shown in Table 3.

  From Table 3, it can be seen that the green light-emitting organic EL device of the present invention is excellent in luminous efficiency, high in durability and long in life, and is an excellent green light-emitting organic EL device. Further, it can be seen that the drive voltage is lowered and the voltage rise during driving is suppressed. Moreover, it turns out that higher luminous efficiency and lifetime can be made compatible by making the organic EL element material which concerns on this invention into a more preferable aspect (for example, a preferable substituent, the number of this substituent, etc.). It can also be seen that the drive voltage can be lowered and the voltage rise during driving can be reduced.

[Example 4]
Organic EL device 1-6 (green light emitting organic EL device), organic EL device 2-6 (blue light emitting organic EL device) prepared in Examples 1 and 2 and phosphorescent compound Ir of organic EL device 1-7 An organic EL element (red light emitting organic EL element) produced in the same manner as the organic EL element 1-1 except that (ppy) ₃ was replaced with the compound Ir-9 shown in [Chemical Formula 14] described above on the same substrate. The active matrix type full-color display device (display) 1 shown in FIG. FIG. 2 shows only a schematic diagram of the display unit A of the produced full-color display device 1 (reference numeral B is a control unit). That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) on the same substrate. Each of the scanning lines 5 and the plurality of data lines 6 in the wiring portion is made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions (details). Is not shown).

The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. Then, an image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, full-color display is possible by appropriately juxtaposing the red, green, and blue pixels.
By driving the full-color display device 1, a clear full-color moving image display with low voltage, high brightness and good durability was obtained.

In addition, even if it combines the above-mentioned red light emitting organic EL element, organic EL elements 1-7 to 1-18 as green light emitting organic EL elements, and 2-7 to 2-18 as blue light emitting organic EL elements at random, Full color display was possible. Further, as the red light-emitting organic EL element, all of the organic EL elements in which the phosphorescent compound Ir (ppy) ₃ of the organic EL elements 1-7 to 1-18 is replaced with Ir-9 have emission luminance, luminous efficiency, and driving voltage. It was an excellent red organic EL device.

[Example 5]
<< Preparation of white organic EL element >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% by mass with pure water at 3000 rpm, 30 After film formation by a spin coating method in seconds, the film was dried at 200 ° C. for 1 hour to provide a hole transport layer having a thickness of 30 nm.
This substrate was transferred to a nitrogen atmosphere, and on the hole transport layer, Exemplified Compound 1-35 (60 mg), Compounds Ir-9 (3.0 mg) and Ir-12 (3.0 mg) shown in the above [Chemical Formula 14] were used. ) Was dissolved in 6 ml of toluene, and a film was formed by spin coating under conditions of 1000 rpm and 30 seconds. And it heated at 150 degreeC in vacuum for 1 hour, and was set as the light emitting layer.

Furthermore, using a solution obtained by dissolving BCP (20 mg) in 6 ml of cyclohexane, a film was formed by spin coating under conditions of 1000 rpm and 30 seconds. And it heated at 80 degreeC in vacuum for 1 hour, and was set as the 1st electron carrying layer.
Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, and 200 mg of Alq ₃ was put into a molybdenum resistance heating boat and attached to the vacuum vapor deposition apparatus. After depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, energize and heat the heating boat containing Alq ₃ , and deposit on the first electron transport layer at a deposition rate of 0.1 nm / second, Further, a second electron transport layer having a thickness of 40 nm was provided. In addition, the substrate temperature at the time of vapor deposition was room temperature.

Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the white light emitting organic EL element was produced.
When this element was energized, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, it turned out that white light emission is obtained similarly even if it replaces with the other compound of illustration.

  Although the present invention has been described in detail with reference to the embodiments and examples, the gist of the present invention is not limited to the above-described contents, and the scope of the right is interpreted based on the description of the claims. There must be. Needless to say, the contents of the present invention can be modified and changed based on the above description.

For example, the display device and the illumination device may have any shape or application as long as they include the organic EL element of the present invention. Moreover, you may apply to another apparatus etc., if the organic EL element of this invention is included and the meaning of this invention is not impaired. And according to the usage, etc., the organic EL element material of the present invention is a paint, a catalyst, an oxidizing agent, an antioxidant, a light stabilizer, an antistatic agent, a highly heat conductive inorganic material, an antiseptic, and a lubricant. You may mix and use substances, such as an agent.
Furthermore, the thin film made of the organic EL element material of the present invention may be formed on the support substrate, the entire lower film of the thin film, or may be formed on a part thereof. Moreover, there may be a case where the film is not formed uniformly.

1. Display device (display)
3 pixels 5 scanning lines 6 data lines A display unit B control unit

Claims (11)

An organic electroluminescent device material, which is a compound represented by the following general formula (1).

[Wherein, X ₁ represents any _one of N, P, P═O, P═S, and SiAr ₁ , and Y ₁ represents any _one of NAr ₂ , O, and S. Ar ₁ and Ar ₂ represent an aromatic hydrocarbon group or an aromatic heterocyclic group. A _{1 to} A ₁₁ each independently represent C—R _x or N, and the plurality of R _x may be the same or different. R _x each independently represents a hydrogen atom, alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxyl group, cycloalkoxyl group, aryl Oxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group , Amino group, nitro group, cyano group, hydroxyl group, alkylsilyl group, arylsilyl group, alkylphosphino group, arylphosphino group, alkylphosphoryl group, arylphosphoryl group, alkylthiophosphoryl group, arylthiophosphoryl Represents a group. ] The organic electroluminescence element material according to claim 1, wherein Y _{1 in the} general formula (1) is O. The organic electroluminescent element material according to claim 2, wherein X _{1 in the} general formula (1) is N.   2. An organic electroluminescence device comprising an organic layer sandwiched between at least a pair of an anode and a cathode, wherein the organic layer comprises at least one layer including a light emitting layer, and at least one of the organic layers is claim 1. The organic electroluminescent element material of any one of Claim 3 is contained, The organic electroluminescent element characterized by the above-mentioned.   The organic light-emitting device according to claim 4, wherein the light-emitting layer contains the organic electroluminescence device material according to claim 1.   The organic light-emitting device according to claim 4, wherein the light-emitting layer contains a phosphorescent dopant.   The organic electroluminescence device according to claim 4, wherein the organic electroluminescence device is manufactured by a wet process.   A display device comprising the organic electroluminescent element according to claim 4.   An illuminating device comprising the organic electroluminescent element according to any one of claims 4 to 7. A compound represented by the following general formula (2):

[Wherein, A _{12 to} A ₂₂ each independently represent C—R _{x 2} or N, and the plurality of R _{x 2} may be the same or different. Each R _x2 independently represents a hydrogen atom, an alkenyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, a halogen atom, an alkoxyl group, an aryloxy group, an amino group, an arylsilyl group, an alkylphosphoryl group, or an arylphosphoryl group; To express. ] 11. The compound according to claim 10, wherein each of A _{12 to} A ₂₂ is C—R _{x 2} .

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