JP2010272727A - Organic electroluminescent element, display, illuminating device, and organic electroluminescent element material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL (electroluminescent) element material which emits specifically shortwave light, shows high luminous efficiency, and has a long light-emission life. <P>SOLUTION: In the organic EL (electroluminescent) element, a light emitting layer contains at least one compound including a partial structure represented by formulas (1), (2), (3) or (4). In formulas (1) to (4), E1a and E1p are each different, and each represent a carbon atom or a nitrogen atom. E1b to E1o and E1q each represent any one of a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom. The skeleton composed of E1a to E1q includes 18π electrons in total. R1a to R1i each represent a hydrogen atom or a substituent, and at least one of them is a group represented by formula (A) (wherein, A1 and A2 represent a carbon atom or a nitrogen atom; A3 to A5 each represent any one of a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom; the bonds of A<SB>1</SB>and A<SB>2</SB>, A<SB>2</SB>and A<SB>3</SB>, A<SB>3</SB>and A<SB>4</SB>, A<SB>4</SB>and A<SB>5</SB>, and A<SB>5</SB>and A<SB>1</SB>each represent a single bond or a double bond; La represents a divalent linking group; and * represents a linking moiety). M represents a group 8-10 transition metal element of the periodic table of elements. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence element, a display device, a lighting device, and an 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 the emission of light (fluorescence / phosphorescence) when the exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Therefore, it has a wide viewing angle, high visibility, and since it is a thin-film type completely solid element, it has attracted attention from the viewpoints of space saving and portability.

  However, in organic EL elements for practical use in the future, development of organic EL elements that emit light efficiently and with high luminance with lower power consumption is desired.

  In Japanese Patent No. 3093796, a small amount of a phosphor is doped into a stilbene derivative, a distyrylarylene derivative or a tristyrylarylene derivative to achieve an improvement in light emission luminance and a longer device lifetime.

  Further, an element having an organic light-emitting layer in which an 8-hydroxyquinoline aluminum complex is used as a host compound and a small amount of phosphor is doped thereto (for example, JP-A 63-264692), and an 8-hydroxyquinoline aluminum complex is used as a host compound. For example, an element having an organic light emitting layer doped with a quinacridone dye (for example, JP-A-3-255190) is known.

  As described above, when light emission from excited singlet is used, the generation ratio of singlet excitons and triplet excitons is 1: 3, and thus the generation probability of luminescent excited species is 25%. Since the efficiency is about 20%, the limit of the external extraction quantum efficiency (η) is set to 5%.

  However, since Princeton University reported on an organic EL device using phosphorescence emission from an excited triplet (MA Baldo et al., Nature, 395, 151-154 (1998)), Research on materials that exhibit phosphorescence has become active.

  For example, M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), US Pat. No. 6,097,147, and the like.

  When the excited triplet is used, the upper limit of the internal quantum efficiency is 100%. In principle, the luminous efficiency is four times that of the excited singlet, and there is a possibility that almost the same performance as a cold cathode tube can be obtained. Therefore, it is attracting attention as a lighting application.

  For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), etc., many compounds are being studied for synthesis centering on heavy metal complexes such as iridium complexes.

  In addition, the aforementioned M.I. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), studies have been made using tris (2-phenylpyridine) iridium as a dopant.

In addition, M.M. E. Thompson et al., In The 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), used L ₂ Ir (acac), for example, (ppy) ₂ Ir (acac), e 0 g, Tetsuo Tsutsui, etc., again The 10th International Workshop on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), the dopant as tris (2-(p-tolyl) pyridine) iridium (Ir _{(ptpy) 3),} tris ( Studies using benzo [h] quinoline) iridium (Ir (bzq) ₃ ) and the like are being conducted (note that these metal complexes are generally called orthometalated iridium complexes).

  In addition, the S. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001) and Japanese Patent Application Laid-Open No. 2001-247859, etc., attempts have been made to form devices using various iridium complexes.

  In order to obtain high luminous efficiency, in the 10th International Workshop on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), Ikai et al. Uses a hole transporting compound as a host of a phosphorescent compound. In addition, M.M. E. Thompson et al. Use various electron transporting materials as a host of phosphorescent compounds, doped with a novel iridium complex.

  Orthometalated complexes in which the central metal is platinum instead of iridium are also attracting attention. With respect to this type of complex, many examples are known in which ligands are characterized.

  In either case, the light emission brightness and light emission efficiency of the light emitting device are greatly improved compared to conventional devices because the emitted light is derived from phosphorescence. There was a problem that it was lower than the conventional element.

  As described above, it is difficult for phosphorescent highly efficient light-emitting materials to shorten the light emission wavelength and improve the light emission lifetime of the device, and the performance that can withstand practical use cannot be sufficiently achieved.

  In addition, regarding wavelength shortening, introduction of an electron withdrawing group such as a fluorine atom, a trifluoromethyl group, a cyano group or the like into phenylpyridine as a substituent, and picolinic acid or a pyrazabole-based ligand as a ligand. It is known to introduce.

  However, with these ligands, the emission wavelength of the light-emitting material is shortened to achieve blue, and a high-efficiency device can be achieved. On the other hand, the light-emitting lifetime of the device is greatly deteriorated, so an improvement in the trade-off is required. It was.

  It is disclosed that a metal complex having phenylpyrazole as a ligand is a light emitting material having a short emission wavelength (for example, see Patent Documents 1 and 2). Furthermore, a metal complex formed from a ligand having a partial structure in which a 6-membered ring is condensed to a 5-membered ring of phenylpyrazole is disclosed (for example, see Patent Documents 3 and 4). There is a disclosure about a metal complex having a phenanthridine skeleton (see, for example, Patent Documents 5 and 6).

  However, with the metal complexes described in the above-mentioned known documents, the external extraction quantum efficiency is not improved, and a practically sufficient improvement effect is not obtained for the light emission lifetime, and there is a need for improvement. Yes.

International Publication No. 2004/085450 Pamphlet JP 2005-53912 A JP 2006-28101 A US Pat. No. 7,147,937 US Patent Application Publication No. 2007/0190359 International Publication No. 2007/095118 Pamphlet

  The present invention has been made in view of such problems, and an object of the present invention is to use an organic EL device material that exhibits specific short-wave light emission, exhibits high light emission efficiency, and has a long light emission lifetime. An organic EL element, an illumination device, and a display device are provided.

  The above object of the present invention has been achieved by the following constitution.

  1. In an organic electroluminescence device having at least a light emitting layer between an anode and a cathode, the light emitting layer comprises a compound comprising a partial structure represented by the following general formula (1), (2), (3) or (4) An organic electroluminescence device comprising at least one.

[Wherein, E1a and E1p are different from each other and each represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are composed of E1a to E1q. The skeleton has a total of 18π electrons. R1a to R1i each represents a hydrogen atom or a substituent, at least one of which is a group represented by the following general formula (A). M represents a group 8-10 transition metal element in the periodic table. ]

_Wherein, A 1, _{A 2} is a carbon atom or a nitrogen atom. A ₃ to A ₅ each represent a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. The bond between A ₁ and A _2, the bond between A ₂ and A ₃ , the bond between A ₃ and A ₄ , the bond between A ₄ and A ₅ , and the bond between A ₅ and A ₁ each represents a single bond or a double bond . La represents a divalent linking group. * Represents a linking site. ]
2. 2. The organic electroluminescence device according to 1 above, wherein the group represented by the general formula (A) is connected to a ring composed of E1a to E1e.

  3. 2. The organic electroluminescence device according to 1 above, wherein the group represented by the general formula (A) is connected to a ring composed of E1l to E1q.

  4). 2. The organic electroluminescent device according to 1 above, wherein the group represented by the general formula (A) is connected to a ring composed of E1f to E1k.

  5. Any one of the above 1 to 4, wherein the partial structure represented by any one of the general formulas (1) to (4) is represented by any one of the following general formulas (5) to (8) 2. The organic electroluminescence device according to item 1.

[Wherein, E1a and E1p are different and each represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are formed of E1a to E1e. The ring represents a 5-membered aromatic heterocycle, and the ring formed by E1l to E1q represents a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle. R1a to R1i, R51 to R54, R61 to R63, and R71 to R74 each represent a hydrogen atom or a substituent, at least one of which is a group represented by the general formula (A). M represents a group 8-10 transition metal element in the periodic table. X1, X2, and X3 each represent a carbon atom or a nitrogen atom. ]
6). 6. The organic electroluminescence device as described in 5 above, wherein the group represented by the general formula (A) is connected to a ring composed of E1a to E1e.

  7). The group represented by the general formula (A) represents at least one of groups represented by R61 to R63, or is connected to a ring composed of E1l to E1q. 5. The organic electroluminescence device according to 5.

  8). The group represented by the general formula (A) represents at least one of the groups represented by R51 to R54, represents at least one of the groups represented by R71 to R74, or E1f to E1k. 6. The organic electroluminescent device according to 5 above, wherein the organic electroluminescent device is connected to a ring constituted by X 1, X 2, X 3 and a ring constituted by —C═C—. .

  9. 9. The organic electroluminescence device according to any one of 1 to 8, wherein the ring composed of E1a to E1e is an imidazole ring or a pyrazole ring.

  10. Any one of 5 to 9 above, wherein the partial structure represented by any one of the general formulas (5) to (8) is represented by any one of the following general formulas (9) to (12): 2. The organic electroluminescence device according to item 1.

[Wherein, E1f to E1o and E1q each represent a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, E1p represents a carbon atom, and the ring formed by E1f to E1k is a 5-membered aromatic heterocycle] The ring represented by E1l to E1q represents a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocyclic ring. R51 to R56, R61 to R65, R71 to R76, R81, R82, and R1c to R1i represent a hydrogen atom or a substituent, at least one of which is a group represented by the general formula (A). M represents a group 8-10 transition metal element in the periodic table. X1, X2, and X3 each represents a carbon atom or a nitrogen atom that is unsubstituted or has a substituent. ]
11. At least one of R55 and R56, at least one of R64 and R65, at least one of R75 and R76, or at least one of R81 and R82 represents a group represented by the general formula (A). The organic electroluminescent element of description.

  12 11. At least one of R1g, R1h, R1i, at least one of R61, R62, R63, or at least one of R1g, R1h represents a group represented by the general formula (A), Organic electroluminescence device.

  13. At least one of R51 to R54, at least one of R1c to R1e, or at least one of R71 to R74 represents a group represented by the general formula (A), or at least one of X1 to X3 represents the general formula (A 11. The organic electroluminescence device as described in 10 above, which has a group represented by

  14 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (B).

[Wherein, R _{1 to} R ₄ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
15. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (C).

[Wherein, R _{1 to} R ₃ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
16. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (D).

[Wherein R ₁ , R ₂ and R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
17. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (E).

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
18. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (F).

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
19. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (G).

[Wherein R _{2 and} R ₃ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
20. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (H).

[Wherein R _{2 and} R ₃ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
21. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (I).

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
22. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (J).

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
23. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (K).

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
24. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (L).

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
25. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (M).

[Wherein R ₂ , R _{3 and} R ₅ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
26. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (N).

[Wherein R ₁ , R _{3 and} R ₆ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
27. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (O).

[Wherein R ₁ , R ₂ , R _{3 and} R ₇ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
28. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (P).

[Wherein R ₁ , R ₃ , R _{4 and} R ₈ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
29. 14. The organic electroluminescence device according to any one of 1 to 13, wherein the general formula (A) is represented by the following general formula (Q).

[Wherein R ₃ , R _{4 and} R ₉ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]
30. As a constituent layer, it has an organic layer containing at least one compound containing a partial structure represented by any one of the general formulas (1) to (12), and the organic layer was formed using a wet process 30. The organic electroluminescence device as described in any one of 1 to 29 above.

  31. 31. The organic electroluminescence element according to any one of 1 to 30, wherein M is platinum or iridium.

  32. An organic electroluminescent element material comprising at least one compound containing a partial structure represented by any one of the following general formulas (1) to (4).

[Wherein, E1a and E1p are different from each other and each represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are composed of E1a to E1q. The skeleton has a total of 18π electrons. R1a to R1i each represents a hydrogen atom or a substituent, at least one of which is a group represented by the following general formula (A). M represents a group 8-10 transition metal element in the periodic table. ]

_Wherein, A 1, _{A 2} is a carbon atom or a nitrogen atom. A ₃ to A ₅ each represent a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. The bond between A ₁ and A _2, the bond between A ₂ and A ₃ , the bond between A ₃ and A ₄ , the bond between A ₄ and A ₅ , and the bond between A ₅ and A ₁ each represents a single bond or a double bond . La represents a divalent linking group. * Represents a linking site. ]
33. 33. The organic electroluminescent device material as described in 32 above, wherein M is platinum or iridium.

  34. A display device comprising the organic electroluminescence element according to any one of 1 to 31 above.

  35. An illuminating device comprising the organic electroluminescence element according to any one of 1 to 31 above.

  According to the present invention, it is possible to provide an organic EL element that exhibits specific short-wave light emission, exhibits high light emission efficiency, has a low driving voltage, and has a long light emission lifetime, and an illumination device and a display device using the element. did it. Moreover, the organic EL element material useful for organic EL elements was able to be obtained.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. 4 is a schematic diagram of a display unit A. FIG. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full-color display device. It is the schematic of an illuminating device. It is a schematic diagram of an illuminating device.

  In the organic electroluminescent element of this invention, the structure prescribed | regulated to any one of Claims 1-30 WHEREIN: The organic electroluminescent element which shows high luminous efficiency and has a long light emission lifetime, and illumination using this element A device and a display device could be provided.

  In addition, the present inventors succeeded in molecular design of an organic EL element material useful for the organic electroluminescence element of the present invention. The organic electroluminescence device material of the present invention was observed to emit light with a specific short wave, and the lifetime of the organic electroluminescence device of the present invention could be remarkably improved.

  Hereinafter, details of each component according to the present invention will be sequentially described.

《Metal complex (also called metal complex compound)》
The metal complex (also referred to as a metal complex compound) according to the present invention will be described.

  The present inventors paid attention to the organic EL element material used for the light emitting layer of the organic EL element, and examined various metal complex compounds used as a light emitting dopant.

  The present inventors have introduced a substituent into the basic skeleton of a metal complex, and thus it is not a conventionally known approach to control the wavelength or improve the lifetime, but to expand the π-conjugated surface of the condensed ring. Various complexes were studied under the focus of increasing stability.

  As a result, the improvement tendency of lifetime was found in several condensed ring structures. However, when a fused ring as known so far is introduced, the red shift of the emission wavelength is remarkable, resulting in green and red emission.

  The present inventors have further studied and shown in the partial structure represented by any one of the general formulas (1) to (4), (5) to (8), and (9) to (12) according to the present invention. When a compound with a condensed ring introduced (also called a metal complex or metal complex compound) is applied to a light emitting material, the emission wavelength shift is small, and a long lifetime is achieved at a desired emission wavelength. Succeeded in developing a luminescent dopant.

  Further examination of this new basic skeleton has the disadvantage that the π-conjugate plane becomes larger, and the planarity becomes higher, so that the association between metal complexes becomes a problem, and the lifetime of the device is remarkably reduced. I understood.

  As a result of various studies, by introducing the heterocyclic group represented by the general formula (A) into the ligand moiety, association between molecules is prevented and the stability of the metal complex (metal complex compound) is also improved. I found something to do. Furthermore, as a result of various investigations on the types of substituents, it was found that the general formula (A) had the greatest effect when the general formulas (B) to (Q). This is considered to be due to the steric bulk of these substituents and the electronic effect.

  The transition metal complex compounds including the partial structure represented by any one of the general formulas (1) to (4), (5) to (8), and (9) to (12) according to the present invention are each represented by M. Depending on the valence of the transition metal element to be produced, a plurality of ligands can be included, but all of the ligands may be the same or may have ligands having different structures.

  Here, the ligand excludes the transition metal element M from the partial structure represented by any one of the general formulas (1) to (4), (5) to (8), and (9) to (12). Each part is a ligand.

(Conventionally known ligand)
Moreover, as what is called a ligand, the said trader can use together a well-known ligand (it is also called a coordination compound) as a ligand as needed.

  From the viewpoint of preferably obtaining the effects described in the present invention, the type of ligand in the complex is preferably composed of 1 to 2 types, and more preferably 1 type.

  There are various known ligands used in conventionally known metal complexes. For example, “Photochemistry and Photophysics of Coordination Compounds” Springer-Verlag H. Published by Yersin in 1987, “Organometallic Chemistry-Fundamentals and Applications-” Liu Huabo Company, Akio Yamamoto, published in 1982, etc. (for example, halogen ligands (preferably chlorine ligands), Nitrogen heterocyclic ligands (for example, bipyridyl, phenanthroline, etc.) and diketone ligands).

(Transition metal element of group 8-10 of the periodic table)
Formation of a compound (also referred to as a transition metal complex, metal complex, or metal complex compound) containing a partial structure represented by any of the general formulas (1), (2), (3), or (4) according to the present invention As the metal used in the above, a transition metal element of group 8 to 10 of the periodic table (also simply referred to as a transition metal) is used, and among them, iridium and platinum are preferable transition metal elements.

(Contained layer of transition metal complex according to the present invention)
As a content layer of the transition metal complex compound containing the partial structure represented by any one of the general formulas (1) to (4), (5) to (8), and (9) to (12) according to the present invention, The layer is not particularly limited as long as it is a layer that transports charges (charge transport layer), but is preferably a hole transport layer or a light-emitting layer, a light-emitting layer or an electron blocking layer, more preferably a light-emitting layer or an electron blocking layer, particularly Is a light emitting layer.

  Moreover, when it contains in a light emitting layer, by using as a light emission dopant in a light emitting layer, the efficiency improvement (high brightness) of the external extraction quantum efficiency of the organic EL element of this invention and the lifetime improvement of a light emission lifetime are achieved. be able to. The constituent layers of the organic EL element of the present invention will be described in detail later.

  First, the partial structure represented by any one of the general formulas (1) to (12) according to the present invention will be described.

<< Compounds Represented by General Formulas (1) to (12) >>
In the compounds represented by general formulas (1) to (4), preferred structures are represented by general formulas (5) to (8), respectively, and more preferred structures are represented by general formulas (9) to (12).

  First, a skeleton composed of E1a to E1q having a total of 18π electrons will be described.

  In the formula, E1a and E1p are different (respectively) and represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are composed of E1a to E1q. The skeleton has a total of 18π electrons.

  In the general formulas (1) to (12), E1a represents a carbon atom or a nitrogen atom, and E1b to E1e (respectively) represent any of a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, but by E1a to E1e The ring formed represents a 5-membered aromatic heterocycle, for example, an oxazole ring, thiazole ring, oxadiazole ring, oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole ring, isothiazole ring Thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring and the like.

  Among these, a pyrazole ring, an imidazole ring, an oxazole ring, and a thiazole ring are preferable, and an imidazole ring, a pyrazole ring, and a triazole ring are more preferable, and an imidazole ring is particularly preferable.

  Each of these rings may further have a substituent described later.

  In the general formulas (1) to (12), E1f to E1k each represents a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and the ring formed by E1f to E1k is a 6-membered aromatic hydrocarbon Represents a ring, or a 5- or 6-membered aromatic heterocyclic ring.

  Examples of the 6-membered aromatic hydrocarbon ring formed by E1f to E1k include a benzene ring. Furthermore, you may have the substituent mentioned later.

  The 5-membered aromatic heterocycle formed by E1f to E1k is, for example, preferably a pyrazole ring, an imidazole ring, an oxazole ring, and a thiazole ring, more preferably an imidazole ring, a pyrazole ring, and a triazole ring. Preferred is an imidazole ring.

  Examples of the 6-membered aromatic heterocycle formed by E1f to E1k include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring.

  Each of these rings may further have a substituent described later.

  In the general formulas (1) to (12), E1l to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, E1p represents a carbon atom or a nitrogen atom, and is formed by E1l to E1q The ring to be represented represents a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle, and these rings are formed by E1f to E1k in the general formula (1). It is synonymous with a 5-membered aromatic hydrocarbon ring, a 5-membered or 6-membered aromatic heterocyclic ring, respectively.

  In the general formulas (1) to (12), R1a to R1i, R51 to R54, R61 to R63, R71 to R74, R81, and R82 each have, for example, an alkyl group (for example, Methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl) Group), alkenyl group (for example, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group) , Propargyl group, etc.), aromatic hydrocarbon group (aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl 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.), aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, A diazacarbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a phthalazinyl group, etc.), a heterocyclic group (for example, a pyrrolidyl group, an imidazolidyl group, Morpholyl group, oxazolidyl group, etc. , Alkoxy groups (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy groups (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), An aryloxy group (for example, phenoxy group, naphthyloxy group, etc.), an alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentyl group) Thio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group) Octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group) Butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl) Group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl , Dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyl) Oxy group etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group) Group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, Ruaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl Group, 2-pyridylaminocarbonyl 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), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethyl Tylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group) Group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (eg, amino group, ethylamino group, dimethylamino group) , Butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (for example, Fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, Examples include a mercapto group, a silyl group (for example, a trimethylsilyl group, a triisopropylsilyl group, a triphenylsilyl group, a phenyldiethylsilyl group), a phosphono group, and the like.

  Among these substituents, an alkyl group, an aromatic hydrocarbon group, and an aromatic heterocyclic group are preferably used.

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  X1, X2, and X3 in the general formulas (8) and (12) each represent a carbon atom or a nitrogen atom, and together with the carbon-carbon double bond to which they are bonded, a 5-membered aromatic carbocycle or aromatic heterocycle It forms a ring.

  The 5-membered aromatic carbocycle or aromatic heterocycle formed by these is preferably a cyclopentadiene ring, a pyrazole ring, an imidazole ring, a triazole ring or the like, more preferably an imidazole ring or a pyrazole ring. Preferred is an imidazole ring. These rings may further have the substituent.

  In these general formulas (1) to (4), at least one of the substituents represented by the substituents R1a to R1i is a group represented by the general formula (A). Therefore, the general formula (5) R51 to R54 in formula (6), R61 to 63 in formula (6), R71 to R74 in formula (7), R51 to R56 in formula (9), R61 to R65 in formula (10), R71 to 76 in the formula (11) and R81 to R82 in the general formula (12) may be groups represented by the general formula (A).

(Partial structure represented by formula (A))
The partial structure represented by the general formula (A) according to the present invention will be described.

In the general formula (A), A ₁ and A ₂ represent a carbon atom or a nitrogen atom. A ₃ to A ₅ each represent a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. The bond between A ₁ and A _2, the bond between A ₂ and A ₃ , the bond between A ₃ and A ₄ , the bond between A ₄ and A ₅ , and the bond between A ₅ and A ₁ each represents a single bond or a double bond . La represents a divalent linking group. * Represents a linking site. When A _{2 to} A ₅ represent a carbon atom or a nitrogen atom, the carbon atom and the nitrogen atom may have a substituent. In this case, the substituents have the same definitions as the substituents represented by R1a to R1i.

  The group represented by the general formula (A) is preferably represented by any one of the following general formulas (B) to (Q).

Here, R < ₁ > -R < ₉ > represents a hydrogen atom or a substituent.

  As a substituent, it is synonymous with the group quoted as a substituent represented by R1a-R1i in General formula (1)-(4). Among the substituents, an alkyl group, an aromatic hydrocarbon group, and an aromatic heterocyclic group are preferably used.

  In the general formulas (A) to (Q), the divalent linking group represented by La includes hydrocarbon groups such as alkylene groups, alkenylene groups, alkynylene groups, and arylene groups, as well as the alkylene groups and the alkenylene groups. In the alkynylene group and the arylene group, each of them may contain a hetero atom (for example, a nitrogen atom, an oxygen atom, a sulfur atom, a silicon atom, etc.), a thiophene-2,5-diyl group, It may be a divalent linking group derived from a compound having an aromatic heterocycle (also called a heteroaromatic compound) such as a pyrazine-2,3-diyl group, or a chalcogen atom such as oxygen or sulfur.

  Further, it may be a group linked via a hetero atom such as an alkylimino group, a dialkylsilanediyl group or a diarylgermandiyl group.

  Examples of the alkylene group used as the divalent linking group represented by La include an ethylene group, trimethylene group, tetramethylene group, propylene group, ethylethylene group, pentamethylene group, hexamethylene group, 2,2, 4-trimethylhexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, cyclohexylene group (for example, 1,6-cyclohexanediyl group, etc.), cyclopentylene group (For example, 1,5-cyclopentanediyl group) and the like.

  Examples of the alkenylene group used as the divalent linking group represented by L2 include a propenylene group, a vinylene group, and a 4-propyl-2-pentenylene group.

  Examples of the alkynylene group used as the divalent linking group represented by La include an ethynylene group and a 3-pentynylene group.

  Examples of the arylene group used as a divalent linking group represented by La include o-phenylene group, m-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, and naphthylnaphthalenediyl group. Group, biphenyldiyl group (for example, 3,3′-biphenyldiyl group, 4,4′-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terphenyldiyl group, quaterphenyldiyl group, kinkphenyldiyl Group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group and the like.

  Examples of the group having a divalent heterocyclic group used as a divalent linking group represented by La (also referred to as a heteroarylene group) include, for example, an oxazolediyl group, a pyrimidinediyl group, a pyridazinediyl group, a pyrandiyl group, and pyrroline. Examples include diyl group, imidazoline diyl group, imidazolidine diyl group, pyrazolidine diyl group, pyrazoline diyl group, piperidine diyl group, piperazine diyl group, morpholine diyl group, quinuclidine diyl group, and 1,3,4 -Triazole-2,5-diyl group, 1,3,4-oxadiazole-2,5-diyl group, thiophene-2,5-diyl group, pyrrole-2,5-diyl group, pyridine-2,6 -Diyl group, dibenzofuran-2,8-diyl group, dibenzothiophene-2,8-diyl group, N-phenylcarba -3,6-diyl group, N-ethylcarbazole-3,6-diyl group, 4,4-diazacarbazole-3,6-diyl group, pyrazine-2,3-diyl group, It may be a divalent linking group derived from a compound having an aromatic heterocycle (also referred to as a heteroaromatic compound).

  Hereinafter, specific examples of the compound (also referred to as a metal complex or a metal complex compound) having a partial structure represented by the general formulas (1) to (12) according to the present invention will be described, but the present invention is not limited thereto.

  These metal complexes are described in, for example, Organic Letter, vol. 16, 2579-2581 (2001), Inorganic Chemistry, Vol. 30, No. 8, 1685-1687 (1991), J. Am. Am. Chem. Soc. , 123, 4304 (2001), Inorganic Chemistry, Vol. 40, No. 7, 1704-1711 (2001), Inorganic Chemistry, Vol. 41, No. 12, 3055-3066 (2002) , New Journal of Chemistry. 26, 1171 (2002), Organic Letter, vol. 3, pages 415 to 418 (2006), and further by applying methods such as references described in these documents.

  As an example, a synthesis scheme of Compound Example (A-1) is given below.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.

(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 / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode (vi) Anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode In the organic EL device of the present invention, blue light emission The light emission maximum wavelength of the layer is preferably 430 nm to 480 nm, the green light emission layer is preferably a monochromatic light emitting layer having a light emission maximum wavelength of 510 nm to 550 nm, and the red light emission layer is a monochromatic light emitting layer having a light emission maximum wavelength of 600 nm to 640 nm. This is a display device using these. It is preferred.

  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.

  Furthermore, the organic EL element of the present invention is preferably a white light emitting layer, and an illumination device using these is preferable.

  Each layer which comprises the organic EL element of this invention is demonstrated.

<Light emitting layer>
The light emitting layer according to the present invention 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, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The total film thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing unnecessary application of high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust in the range of 2 nm to 5 μm, more preferably in the range of 2 nm to 200 nm, and particularly preferably in the range of 10 nm to 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 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 will be described.

  Here, in the present invention, the host compound is defined as a compound having a phosphorescence quantum yield of phosphorescence emission of less than 0.1 at room temperature (25 ° C.). The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  As the host compound, known 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 light emission dopants mentioned later, and, thereby, arbitrary luminescent colors can be obtained.

  Moreover, it may be a conventionally known low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). As the known host compound that may be used in the present invention, a compound that has a hole transporting ability and an electron transporting ability, that prevents an increase in wavelength of light emission, and has a high Tg (glass transition temperature) is preferable. .

  Specific examples of host compounds that can be used in combination with the present invention are shown below, but the present invention is not limited thereto.

  Specific examples of known host compounds further 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)
Next, the luminescent dopant will be described.

  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, but the emission efficiency is higher. From the viewpoint of obtaining an organic EL device, the light-emitting dopant (sometimes referred to simply 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 contains the above host compound as well as phosphorus. It is preferable to contain a light dopant.

(Phosphorescent dopant)
The phosphorescent dopant will be described.

  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.). Although defined as being a compound of 01 or more, 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 solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.

  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. The energy transfer type that obtains light emission from the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained. Although it is a trap type, in any case, the excited state energy of the phosphorescent dopant is required to be lower than the excited state energy of the host compound.

  The phosphorescent dopant according to the present invention is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), Among the rare earth complexes, iridium compounds are most preferred.

  The phosphorescent dopant can be appropriately selected from known ones used in the light emitting layer of the organic EL device, and the compound used as the phosphorescent dopant according to the present invention is related to the above-mentioned present invention. A transition metal complex compound including a partial structure represented by any one of the general formulas (1) to (12) is preferable. When the metal complex compound according to the present invention is contained in the light-emitting layer, it is used as a light-emitting dopant in the light-emitting layer, so that the efficiency of the external extraction quantum efficiency of the organic EL device of the present invention can be increased (high luminance) and the light emission lifetime can be increased. Long life can be achieved.

  Moreover, you may use together a conventionally well-known light emission dopant as shown below.

(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.

  Next, a charge transport layer used as a constituent layer of the organic EL device of the present invention, that is, an injection layer, a blocking layer, an electron transport layer, and the like will be described.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  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 as described above. 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 transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking.

  Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

  The hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  The hole blocking layer contains the carbazole derivative, carboline derivative, diazacarbazole derivative (one in which one of the carbon atoms constituting the carboline ring of the carboline derivative is replaced with a nitrogen atom) mentioned as the host compound. It is preferable to do.

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this 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 anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting 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) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a 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.

  In addition, it is also possible to contain in the hole blocking layer a compound having a partial structure represented by any one of the general formulas (1) to (12) according to the present invention.

  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 nm to 100 nm, and more preferably 5 nm to 30 nm.

  In addition, it is also possible to contain in the electron blocking layer a compound having a partial structure represented by any one of the general formulas (1) to (12) according to the present invention.

《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 one 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, and also 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-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 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 nm-200 nm. The 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.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide 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 used as an electron transport material. 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, 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), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer Can also be used as an electron transporting material.

  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 nm-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. 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.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

"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 selected in the range of 10 nm to 1000 nm, preferably 10 nm 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₎ mixture, indium, a lithium / aluminum mixture, and rare earth metals. 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 a 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 nm 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 light emission luminance is improved, which is convenient.

  Moreover, after producing the said metal by the film thickness of 1 nm-20 nm to a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《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.

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. 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. A high barrier film having a permeability of 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.

  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, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method described in JP 2004-68143 A is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

  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.

  As a sealing member, it 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. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. 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 of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less measured by a method according to JIS K 7126-1987, and a method according to JIS K 7129-1992. It is preferable that the water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured in (1) is 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 adhesively cured from room temperature to 80 ° C. 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, ion plating, plasma polymerization, atmospheric pressure plasma A combination 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, and the like 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 taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. 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 of improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate and preventing total reflection at the transparent substrate and the air interface (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 between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. 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 to provide, for example, a microlens array-like structure on the light extraction side of the substrate, or in combination with a so-called condensing sheet, so that the organic EL device is in front of a specific direction, for example, the device light emitting surface. By condensing in the 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 two-dimensionally arranged 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, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  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., Ltd. 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 / hole blocking layer / electron transport 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 so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm, to form an anode.

  Next, organic compound thin films such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, are formed thereon.

  Examples of the method for forming each layer include a vapor deposition method and a wet process (also referred to as a coating method, such as a spin coating method, a casting method, an ink jet method, and a printing method) as described above. In the present invention, film formation by a wet process (coating method) such as a spin coating method, an ink jet method, or a printing method is preferable.

  Examples of the liquid medium for dissolving or dispersing the organic EL material include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, mesitylene, cyclohexylbenzene, and the like. Aromatic hydrocarbons, 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 1 μm or less, preferably by a method such as vapor deposition or sputtering so that the film thickness is in the range of 50 nm 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 V to 40 V with the anode as + and the cathode as-. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<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 Although the light source of a sensor etc. are mentioned, It is not limited to this, It can use effectively for the use as a backlight of a liquid crystal display device, and an illumination light source especially.

  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. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). 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.

<Display device>
The display device of the present invention will be described. The display device of the present invention has the organic EL element.

  The display device of the present invention may be monochromatic or multicolor, but here, the multicolor display device will be described. In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.

  When patterning is performed only on the light-emitting layer, the method is not limited, but a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.

  Moreover, it is also possible to reverse the production order to produce the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport 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 when a voltage of about 2 V to 40 V is applied with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs.

  Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

  The multicolor display device can be used as a display device, a display, and various light emission sources. In a display device or display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  Light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. For example, it is not limited to this.

《Lighting device》
Further, the organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display).

  The driving method when used as a display device for moving image reproduction may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using two or more organic EL elements of the present invention having different emission colors.

  Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a display device composed of organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.

  The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside, and the pixels for each scanning line respond to the image data signal by the scanning signal. The image information is sequentially emitted to scan the image and display the image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below.

  In the figure, the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning line 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not)

  When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data.

  Full-color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region on the same substrate.

  Next, the light emission process of the pixel will be described.

  FIG. 3 is a schematic diagram of a pixel.

  The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10, and the power supply line 7 connects to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.

  When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 maintains the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.

  That is, the light emission of the organic EL element 10 is performed by providing the switching transistor 11 and the drive transistor 12 which are active elements with respect to the organic EL element 10 of each of the plurality of pixels, and light emission of the organic EL element 10 of each of the plurality of pixels 3. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or by turning on / off a predetermined light emission amount by a binary image data signal. Good. The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

  FIG. 4 is a schematic diagram of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.

  When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.

  In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

  The organic EL material of the present invention can be applied as an illumination device to an organic EL element that emits substantially white light. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of blue, green, and blue, or two using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

  In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. Any of those combined with a dye material that emits light may be used, but in the white organic EL device according to the present invention, only a combination of a plurality of light-emitting dopants may be mixed.

  It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask or the like is not necessary. In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, etc., and productivity is also improved. According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.

  There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display element, the metal complex which concerns on this invention so that it may suit the wavelength range corresponding to CF (color filter) characteristic, Any one of known luminescent materials may be selected and combined to whiten.

  As described above, the white light emitting organic EL element according to the present invention is used as a kind of lamp such as household illumination, interior lighting, and exposure light source as various light emitting light sources and lighting devices in addition to the display device and display. It is also useful for display devices such as backlights for liquid crystal display devices.

  Others such as backlights for watches, signboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. There are a wide range of uses such as household appliances.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. Moreover, the structure of the compound used in an Example is shown below.

Example 1
<< Production of Organic EL Element 1-1 >>
A transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) 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 was fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD was put in a molybdenum resistance heating boat, and 200 mg of H-1 as a host compound was put in another molybdenum resistance heating boat, 200 mg of BAlq was put into another resistance heating boat made of molybdenum, 100 mg of Comparative 1 was put into another resistance heating boat made of molybdenum, and 200 mg of Alq ₃ was put into another resistance heating boat made of molybdenum, 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 heated by heating, 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 H-1 and Comparative 1 was energized and heated, and co-deposited on the hole transport layer at a deposition rate of 0.2 nm / second and 0.012 nm / second, respectively. A 40 nm light emitting layer was provided. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Further, the heating boat containing BAlq was energized and heated, and was deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide a 10 nm thick hole blocking layer.

In addition, the heating boat containing Alq ₃ is further energized and heated, and deposited on the hole blocking layer at a deposition rate of 0.1 nm / second to further provide an electron transport layer having a thickness of 40 nm. It was. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, 0.5 nm of lithium fluoride and 110 nm of aluminum were deposited to form a cathode, and an organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-35 >>
In the production of the organic EL device 1-1, the organic EL devices 1-2 to 1 were similarly prepared except that H-1 as the host compound of the light emitting layer and Comparative 1 as the dopant compound were replaced with the compounds shown in Table 1. -35 was produced.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 1-1 to 1-35, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 3 and 4 was formed and evaluated.

  FIG. 5 shows a schematic diagram of the lighting device, and the organic EL element 101 is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is performed in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere. (In a high purity nitrogen gas atmosphere with a purity of 99.999% or more).

  6 shows a cross-sectional view of the lighting device. In FIG. 6, reference numeral 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

(External quantum efficiency)
By lighting the organic EL element under a constant current condition of room temperature (about 23 to 25 ° C.) and ^2.5 mA / cm ² , and measuring the light emission luminance (L) [cd / m ² ] immediately after the start of lighting, The external extraction quantum efficiency (η) was calculated. Here, CS-1000 (manufactured by Konica Minolta Sensing) was used for measurement of light emission luminance.

  The external extraction quantum efficiency was expressed as a relative value with the organic EL element 1-1 as 100.

(50 ° C drive life)
The 50 ° C. driving life was evaluated according to the measurement method shown below.

Each organic EL element is driven at a constant current with a current that gives an initial luminance of 1000 cd / m ² under a constant condition of 50 ° C., and a time that is ½ of the initial luminance (500 cd / m ² ) is obtained. A measure of lifespan. In addition, 50 degreeC drive lifetime was displayed by the relative value when the comparative organic EL element 1-1 was set to 100.

(Dark spot)
The light emitting surface when each organic EL element was continuously lit under a constant current condition of ^2.5 mA / cm ² at room temperature was visually evaluated. Rank evaluation was performed as follows by visual evaluation by 10 people extracted at random.

×: Number of people who confirmed dark spots was 5 or more. Δ: Number of people confirmed dark spots was 1-4. ○: Number of people who confirmed dark spots was 0.

(Luminescent color)
The organic EL device was visually evaluated for the luminescent color when the organic EL device was continuously lit under a constant current condition of ^2.5 mA / cm ² at room temperature. The obtained results are shown in Table 1.

  In addition, the measurement result of 50 degreeC drive lifetime of Table 1 was represented by the relative value when the organic EL element 1-1 was set to 100.

  From Table 1, it is clear that the organic EL device of the present invention has a high external extraction quantum efficiency and a small deterioration in lifetime under high temperature as compared with the comparative device.

Example 2
<Production of full-color display device>
(Production of blue light emitting element)
The organic EL element 1-7 of Example 1 was used as a blue light emitting element.

(Production of green light emitting element)
In the organic EL element 1-1 of Example 1, a green light emitting element was produced in the same manner except that the comparison 1 was changed to Ir-1, and this was used as the green light emitting element.

(Production of red light emitting element)
In the organic EL device 1-1 of Example 1, a red light emitting device was produced in the same manner except that the comparison 1 was changed to Ir-9, and this was used as a red light emitting device.

  The red, green, and blue light-emitting organic EL elements produced above were juxtaposed on the same substrate to produce an active matrix type full-color display device having the configuration shown in FIG. In FIG. 2, only the schematic diagram of the display part A of the produced display device is shown.

  That is, a plurality of pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) juxtaposed with a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate. The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each 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 (for details, see FIG. 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. The image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, a full color display device was produced by appropriately juxtaposing red, green, and blue pixels.

  It has been found that when this full-color display device is driven, a high-brightness, high durability, and clear full-color moving image display can be obtained.

Example 3
<< Preparation of white light emitting element and white lighting device >>
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% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 30 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of compound A dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. After irradiating with ultraviolet light for 180 seconds to carry out photopolymerization / crosslinking, vacuum drying was performed at 60 ° C. for 1 hour to form a second hole transport layer.

  Next, using a solution obtained by dissolving Compound B (60 mg), Ir-14 (3.0 mg), and A-99 (3.0 mg) in 6 ml of toluene, a film is formed by spin coating under conditions of 1000 rpm and 30 seconds. did. Irradiated with ultraviolet light for 15 seconds to cause photopolymerization and crosslinking, and further heated in vacuum at 150 ° C. for 1 hour to obtain a light emitting layer.

  Further, a solution of compound C (20 mg) dissolved in 6 ml of toluene was used to form a film by spin coating under conditions of 1000 rpm and 30 seconds. Ultraviolet light was irradiated for 15 seconds, photopolymerization / crosslinking was performed, and further heating was performed in vacuum at 80 ° C. for 1 hour to form a hole blocking layer.

Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, 200 mg of Alq ₃ was placed in a molybdenum resistance heating boat, and attached to the vacuum vapor deposition apparatus. After depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, energizing and heating the heating boat containing Alq ₃ , depositing on the hole blocking layer at a deposition rate of 0.1 nm / second, An 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.

Example 4
<< Preparation of Organic EL Element 4-1 >>
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% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 30 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of compound A dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. After irradiating with ultraviolet light for 180 seconds to carry out photopolymerization / crosslinking, vacuum drying was performed at 60 ° C. for 1 hour to form a second hole transport layer.

  Next, a solution in which H-1 (60 mg) and Comparative 1 (3.0 mg) were dissolved in 6 ml of toluene was formed by spin coating under conditions of 1000 rpm and 30 seconds to provide a light emitting layer.

Subsequently, this substrate was fixed to a substrate holder of a vacuum deposition apparatus, 200 mg of BAlq was put into a molybdenum resistance heating boat, and attached to the vacuum deposition apparatus. After reducing the pressure of the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing BAlq is heated by heating, evaporated onto the light emitting layer at a deposition rate of 0.1 nm / second, and further an electron having a thickness of 40 nm. A transport layer 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.

<< Production of Organic EL Elements 4-2 to 4-35 >>
In the production of the organic EL element 4-1, organic EL elements 4-2 to 4-35 were produced in the same manner except that the combination of the dopant compound of the light emitting layer and the host compound was changed to the combination shown in Table 2.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 4-2 to 4-35, the non-light-emitting surface of each organic EL element after production is covered with a glass case, and a glass substrate having a thickness of 300 μm is used as a sealing substrate. An epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 5 and 6 was formed and evaluated.

  FIG. 5 shows a schematic diagram of the lighting device, and the organic EL element 101 is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is performed in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere. (In a high purity nitrogen gas atmosphere with a purity of 99.999% or more).

  FIG. 6 is a cross-sectional view of the lighting device, 105 is a cathode, 106 is an organic EL layer, and 107 is a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

(External quantum efficiency)
By lighting the organic EL element under a constant current condition of room temperature (about 23 to 25 ° C.) and ^2.5 mA / cm ² , and measuring the light emission luminance (L) [cd / m ² ] immediately after the start of lighting, The external extraction quantum efficiency (η) was calculated.

  Here, CS-1000 (manufactured by Konica Minolta Sensing) was used for measurement of light emission luminance. The external extraction quantum efficiency was expressed as a relative value with the organic EL element 1-1 as 100.

(Drive voltage)
The drive voltage was evaluated according to the measurement method shown below.

The driving voltage when each organic EL element was driven at a constant current with a current giving an initial luminance of 1000 cd / m ² was obtained and displayed as a relative value when the driving voltage of the organic EL element 4-1 was 100.

(Stillness stability of light emitting layer coating solution)
In preparation of each organic EL element, the coating solution used for forming the light emitting layer (in the case of the organic EL element 1-1, a mixture of H-1 (60 mg) and Comparative 1 (3.0 mg) was dissolved in 12 ml of toluene. The solution, in other cases, a solution in which each host compound and each dopant compound mixture was dissolved in toluene) was allowed to stand at room temperature for 1 hour, and then a test for confirming the presence or absence of precipitation was performed.

○: No visual observation Δ: Visual precipitation is faintly observed X: Precipitation is clearly visible visually The results are shown below for the organic EL elements 4-1 to 4-35.

  From Table 2, it is clear that the organic EL device of the present invention has a high external extraction quantum efficiency and a low driving voltage as compared with the comparative device, and that the compound of the present invention has good solubility. It is.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water catcher

Claims (35)

In an organic electroluminescence device having at least a light emitting layer between an anode and a cathode, the light emitting layer comprises a compound comprising a partial structure represented by the following general formula (1), (2), (3) or (4) An organic electroluminescence device comprising at least one.

[Wherein, E1a and E1p are different from each other and each represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are composed of E1a to E1q. The skeleton has a total of 18π electrons. R1a to R1i each represents a hydrogen atom or a substituent, at least one of which is a group represented by the following general formula (A). M represents a group 8-10 transition metal element in the periodic table. ]

_Wherein, A 1, _{A 2} is a carbon atom or a nitrogen atom. A ₃ to A ₅ each represent a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. The bond between A ₁ and A _2, the bond between A ₂ and A ₃ , the bond between A ₃ and A ₄ , the bond between A ₄ and A ₅ , and the bond between A ₅ and A ₁ each represents a single bond or a double bond . La represents a divalent linking group. * Represents a linking site. ]   2. The organic electroluminescence device according to claim 1, wherein the group represented by the general formula (A) is connected to a ring composed of E1a to E1e.   2. The organic electroluminescent device according to claim 1, wherein the group represented by the general formula (A) is connected to a ring composed of E1l to E1q.   2. The organic electroluminescent device according to claim 1, wherein the group represented by the general formula (A) is connected to a ring composed of E1f to E1k. The partial structure represented by any one of the general formulas (1) to (4) is represented by any one of the following general formulas (5) to (8). 2. The organic electroluminescence device according to item 1.

[Wherein, E1a and E1p are different and each represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are formed of E1a to E1e. The ring represents a 5-membered aromatic heterocycle, and the ring formed by E1l to E1q represents a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle. R1a to R1i, R51 to R54, R61 to R63, and R71 to R74 each represent a hydrogen atom or a substituent, at least one of which is a group represented by the general formula (A). M represents a group 8-10 transition metal element in the periodic table. X1, X2, and X3 each represent a carbon atom or a nitrogen atom. ]   6. The organic electroluminescence device according to claim 5, wherein the group represented by the general formula (A) is connected to a ring composed of E1a to E1e.   The group represented by the general formula (A) represents at least one of groups represented by R61 to R63 or is connected to a ring composed of E1l to E1q. Item 6. The organic electroluminescence device according to Item 5.   The group represented by the general formula (A) represents at least one of the groups represented by R51 to R54, represents at least one of the groups represented by R71 to R74, or E1f to E1k. 6. The organic electroluminescence according to claim 5, wherein the organic electroluminescence is connected to a ring composed of X 1, X 2, X 3 and —C═C—. element.   The organic electroluminescent element according to claim 1, wherein the ring composed of E1a to E1e is an imidazole ring or a pyrazole ring. The partial structure represented by any one of the general formulas (5) to (8) is represented by any one of the following general formulas (9) to (12). 2. The organic electroluminescence device according to item 1.

[Wherein, E1f to E1o and E1q each represent a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, E1p represents a carbon atom, and the ring formed by E1f to E1k is a 5-membered aromatic heterocycle] The ring represented by E1l to E1q represents a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocyclic ring. R51 to R56, R61 to R65, R71 to R76, R81, R82, and R1c to R1i represent a hydrogen atom or a substituent, at least one of which is a group represented by the general formula (A). M represents a group 8-10 transition metal element in the periodic table. X1, X2, and X3 each represents a carbon atom or a nitrogen atom that is unsubstituted or has a substituent. ]   The at least one of R55 and R56, at least one of R64 and R65, at least one of R75 and R76, or at least one of R81 and R82 represents a group represented by the general formula (A). 10. The organic electroluminescence device according to 10.   11. At least one of the R1g, R1h, and R1i, at least one of R61, R62, and R63, or at least one of R1g and R1h represents a group represented by the general formula (A). Organic electroluminescence element.   At least one of R51 to R54, at least one of R1c to R1e, or at least one of R71 to R74 represents a group represented by the general formula (A), or at least one of X1 to X3 represents the general formula (A The organic electroluminescent element according to claim 10, which has a group represented by: The said general formula (A) is represented by the following general formula (B), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{1 to} R ₄ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (C), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{1 to} R ₃ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (D), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R ₁ , R ₂ and R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (E), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (F), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (G), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R _{2 and} R ₃ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (H), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R _{2 and} R ₃ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (I), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (J), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (K), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (L), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein, R _{2 and} R ₄ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (M), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R ₂ , R _{3 and} R ₅ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (N), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R ₁ , R _{3 and} R ₆ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (O), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R ₁ , R ₂ , R _{3 and} R ₇ each represents a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (P), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R ₁ , R ₃ , R _{4 and} R ₈ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ] The said general formula (A) is represented by the following general formula (Q), The organic electroluminescent element of any one of Claims 1-13 characterized by the above-mentioned.

[Wherein R ₃ , R _{4 and} R ₉ each represent a hydrogen atom or a substituent, and La represents a divalent linking group. * Represents a linking site. ]   As a constituent layer, it has an organic layer containing at least one compound containing a partial structure represented by any one of the general formulas (1) to (12), and the organic layer was formed using a wet process The organic electroluminescent element according to any one of claims 1 to 29, wherein   31. The organic electroluminescent element according to claim 1, wherein M is platinum or iridium. An organic electroluminescent element material comprising at least one compound containing a partial structure represented by any one of the following general formulas (1) to (4).

[Wherein, E1a and E1p are different from each other and each represent a carbon atom or a nitrogen atom, and E1b to E1o and E1q each represent any of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and are composed of E1a to E1q. The skeleton has a total of 18π electrons. R1a to R1i each represents a hydrogen atom or a substituent, at least one of which is a group represented by the following general formula (A). M represents a group 8-10 transition metal element in the periodic table. ]

_Wherein, A 1, _{A 2} is a carbon atom or a nitrogen atom. A ₃ to A ₅ each represent a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom. The bond between A ₁ and A _2, the bond between A ₂ and A ₃ , the bond between A ₃ and A ₄ , the bond between A ₄ and A ₅ , and the bond between A ₅ and A ₁ each represents a single bond or a double bond . La represents a divalent linking group. * Represents a linking site. ]   33. The organic electroluminescent element material according to claim 32, wherein M is platinum or iridium.   A display device comprising the organic electroluminescence element according to claim 1.   The illuminating device provided with the organic electroluminescent element of any one of Claims 1-31.

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