JP2010040829A - Organic electroluminescent element, display device, and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element material that shows high luminous efficiency in blue to bluish green color, and has a long service life and a low drive voltage. <P>SOLUTION: In the organic electroluminescent element including at least one luminous layer sandwiched by positive and negative electrodes, the luminous layer has a ligand comprising six-membered ring or five-membered ring of aromatic groups replaced by an imidazole ring or a pyrazole ring, and includes at least one complex compound having group 8 to group 10 transition metals. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence element, a display device, and a lighting device.

  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 compound that emits light 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 (see, for example, 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 disclosure of metal complexes having a phenanthridine skeleton. (For example, refer to 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.

  Conventionally, a compound having a plurality of carbazole rings in the molecule is known as a good host compound. Also in the compound having the phenanthridine skeleton, a combination example with m-CBP is disclosed (for example, see Patent Documents 5 and 6).

However, as is clear from the above-mentioned patent documents, the combined use with various phenanthridine compounds is still insufficient in terms of life and efficiency, and further improvement is necessary.
International Publication No. 2004/085450 Pamphlet JP 2005-53912 A JP 2006-28101 A US Pat. No. 7,147,937 US Patent No. 20070190359 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.

  In particular, it is to provide an organic EL element material that exhibits high light emission efficiency with short-wave light emission of blue to blue-green, has a low driving voltage, and has a long light emission lifetime.

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

  1. In an organic electroluminescence device including at least one light emitting layer sandwiched between an anode and a cathode, the light emitting layer is represented by the following general formula (1), (2), (3), or (4) Organic electroluminescence comprising an organic layer containing at least one compound containing a partial structure and containing at least one compound containing a partial structure represented by the following general formula (5) or (6) element.

[In formula, E1a-E1q represents a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and the frame | skeleton comprised by E1a-E1q has a total of 18 (pi) electrons. E1a and E1p are different from each other and represent a carbon atom or a nitrogen atom. R1a to R1i each represents a hydrogen atom or a substituent. M represents a group 8-10 transition metal element in the periodic table. ]

[Wherein, A ₁ and A ₂ each independently represent a single bond or an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent.
R _{1 to} R ₂₀ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (one or two or more methylene groups not adjacent to the alkyl group are- O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, —C≡C— may be substituted, and one or more The methylene group may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, and the hydrogen atom in the alkyl group is a fluorine atom. A cycloalkyl group having 3 to 20 carbon atoms (one or two or more methylene groups not adjacent to the cycloalkyl group may be -O-, -S-, -CO-,- Replaced by CO-O-, -O-CO-, -CH = CH- And one or two or more methylene groups may be substituted with an optionally substituted arylene group or an optionally substituted divalent heterocyclic group. Or a hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.), An aryl group which may have a substituent or a heterocyclic group which may have a substituent. Adjacent ones may be bonded to form a ring structure. ]
2. 2. The organic electroluminescence device according to 1 above, wherein the compound containing the partial structure represented by the general formula (5) or (6) is represented by any one of the general formulas (7) to (12) .

[Wherein, m1, m2, n1, and n2 are each an integer of 0-6.
However, m1 + n1 ≦ 6 and m2 + n2 ≦ 6.
m3, m4, m5, m6, n3, n4, n5 and n6 are each an integer of 1-6. However, m3 + n3 ≦ 6, m4 + n4 ≦ 6, m4 + n4 ≦ 6, m5 + n5 ≦ 6, and m6 + n6 ≦ 6.

X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ are each a single bond, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or It represents an mx + nx valent group selected from an amino group which may have a substituent. Here, x represents any one of 1-6.

A ₁ and A ₂ each independently represent a single bond or an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent.

A ₃ and A ₄ each independently represent a single bond or an aryl group which may have a substituent or a heterocyclic group which may have a substituent.

R _{1 to} R ₂₀ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (one or two or more methylene groups not adjacent to the alkyl group are- O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, —C≡C— may be substituted, and one or more The methylene group may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, and the hydrogen atom in the alkyl group is a fluorine atom. A cycloalkyl group having 3 to 20 carbon atoms (one or two or more methylene groups not adjacent to the cycloalkyl group may be -O-, -S-, -CO-,- Replaced by CO-O-, -O-CO-, -CH = CH- And one or two or more methylene groups may be substituted with an optionally substituted arylene group or an optionally substituted divalent heterocyclic group. Or a hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.), An aryl group which may have a substituent or a heterocyclic group which may have a substituent. Adjacent ones may be bonded to form a ring structure. ]
3. 3. The organic electroluminescent device according to 2 above, wherein the linking group represented by X _{1 to} X ₆ in the general formulas (7) to (12) is an aromatic ring group or an aromatic heterocyclic group. .

4). The linking group represented by X _{1 to} X ₆ in the general formulas (7) to (12) is a phenyl group, a biphenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a fluorenyl group, a pyrenyl group, or an anthracenyl group. 4. The organic electroluminescence device as described in 2 or 3 above, which is a divalent group formed by removing one hydrogen atom from the above, and a group comprising a combination thereof.

  5. 5. The organic electroluminescence device according to any one of 2 to 4, wherein a glass transition temperature in the compounds represented by the general formulas (7) to (12) is 100 ° C. or higher.

6). That at least one of the substituents represented by R _{1 to} R ₁₀ or R _{1 to} R ₂₀ in the compounds represented by the general formulas (7) to (12) is a polymerizable substituent. The organic electroluminescence device according to any one of 2 to 5, which is characterized in that

  7). 7. The organic electroluminescence device according to any one of 1 to 6, wherein the ring composed of E1a to E1e is an imidazole ring or a pyrazole ring.

  8). 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 (4), and the organic layer was formed using a wet process 8. The organic electroluminescence device as described in any one of 1 to 7 above.

  9. It has an organic layer containing at least one compound represented by any one of the general formulas (7) to (12) as a constituent layer, and the organic layer is formed using a wet process. The organic electroluminescence device according to any one of 2 to 8 above.

  10. The organic layer containing at least one compound represented by any one of the general formulas (7) to (12) as a constituent layer is a light emitting layer, any one of the above 2 to 9, The organic electroluminescent element of description.

  11. Any one of 2 to 10 above, wherein the organic layer contains at least one polymer having a partial structure of the compound represented by any one of the general formulas (7) to (12). The organic electroluminescent element of description.

  12 Any one of said 1-11 characterized by containing the polymer which makes a partial structure the compound containing the partial structure represented by either of the said General formula (1)-(4). The organic electroluminescent element of description.

  13. Said M is platinum or iridium, The organic electroluminescent element of any one of said 1-12 characterized by the above-mentioned.

  14 14. A display device comprising the organic electroluminescence element according to any one of 1 to 13 above.

  15. 14. An illumination device comprising the organic electroluminescence element according to any one of 1 to 13 above.

  According to the present invention, it has been possible to provide an organic EL device that exhibits specific short-wave light emission, exhibits high light emission efficiency, has a low driving voltage, and has a long light emission lifetime.

  Further, as a result of investigations by the inventors, the present invention has been able to significantly reduce initial deterioration at the start of element driving. Furthermore, the generation of dark spots in the light-emitting element during element driving was successfully reduced, and a useful organic EL element could be provided.

  In addition, an illumination device and a display device using the element could be provided. Furthermore, the organic EL element material useful for organic EL elements was able to be obtained.

  In the organic electroluminescent element of this invention, the structure prescribed | regulated in any one of Claims 1-19 WHEREIN: The organic electroluminescent element which shows high luminous efficiency and has a long light emission lifetime, and illumination using this element Device and 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 element material of the present invention was observed to emit light with a specific short wave, and the lifetime of the organic electroluminescence element 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 compounds (metal complexes, metals) in which a condensed ring as shown in the partial structure represented by any one of the general formulas (1) to (4) according to the present invention is introduced. In the case where a complex compound) is applied to a light emitting material, the present inventors have succeeded in developing a light emitting dopant having a small emission wavelength shift and a long lifetime at a desired emission wavelength.

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

  As for the waveform, sub-luminescence is seen on the long wave side, and a decrease in color purity has become a problem. As a result of various investigations, by introducing at least one substituent into the ligand moiety, association between molecules can be prevented, side-light emission on the long wave side can be suppressed, and the stability of the metal complex (metal complex compound). Was also found to improve.

  In addition, these metal complexes are characterized by significant oxidative degradation due to oxygen and light, and there has been concern over degradation over time during handling. As a result of various investigations, R1a in the transition metal complex compound containing at least one substituent in the ligand portion, particularly a partial structure represented by any one of the general formulas (1) to (4) according to the present invention. It has been found that the introduction of a substituent into the group significantly reduces oxidative degradation and greatly improves the stability of the compound.

  The transition metal complex compound containing the partial structure represented by any one of the general formulas (1) to (4) according to the present invention has a plurality of ligands depending on the valence of the transition metal element represented by M. The ligands may all be the same, or may have ligands each having a different structure.

  Here, the ligand is a portion obtained by removing the transition metal element M from the partial structure represented by any one of the general formulas (1) to (4).

(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 the ligand in the complex is preferably composed of 1 to 2 types, more preferably 1 type.

  As a ligand used for a conventionally known metal complex, there are various known ligands. 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)
The transition metal complex compound-containing layer containing the partial structure represented by any one of the general formulas (1) to (4) according to the present invention is not particularly limited as long as it is a layer that transports charges (charge transport layer). However, a hole transport layer or a light emitting layer, a light emitting layer or an electron blocking layer is preferable, a light emitting layer or an electron blocking layer is more preferable, and a light emitting layer is particularly preferable.

  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 of the general formulas (1) to (4) according to the present invention will be described.

<< Partial structure represented by any one of general formulas (1) to (4) >>
The partial structure represented by any one of the general formulas (1) to (4) according to the present invention will be described.

  In the partial structure represented by any one of the general formulas (1) to (4), the ring formed by E1a to E1e represents a 5-membered aromatic heterocycle, such as an oxazole ring, thiazole ring, or oxadi Examples include azole 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 a pyrazole ring and an imidazole ring are particularly preferable.

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

  In the partial structure represented by any one of the general formulas (1) to (4), the ring formed by E1f to E1k is a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle. To express.

  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.

  Examples of the 5- or 6-membered aromatic heterocycle formed by E1f to E1k include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. can give.

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

  In the partial structure represented by any one of the general formulas (1) to (4), the ring formed by E1l to E1p is a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle. These rings are each synonymous with a 6-membered aromatic hydrocarbon ring or 5-membered or 6-membered aromatic heterocycle formed by E1f to E1k.

  In the partial structure represented by any one of the general formulas (1) to (4), each of the substituents represented by R1a to R1i includes an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an 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, etc.), alkenyl group (for example, vinyl group, Allyl group), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon ring group (aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl group, Tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenyl For example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, , 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, Thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group) One is replaced by a nitrogen atom) Noxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy) Group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.) Alkylthio groups (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio groups (for example, cyclopentylthio 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, octyl) Aminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), Group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.) An acyloxy group (eg, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (eg, methylcarbonylamino group, ethylcarbonylamino group) Group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group Group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylamino) Carbonyl 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 naphthyluree Id group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl 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, dodecylsulfonyl group etc.), arylsulfonyl group or heteroarylsulfonyl group (Eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (eg, amino group, ethylamino group, dimethyla 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 (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, Triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono group and the like. These substituents may be further substituted with the above substituents.

  A plurality of these substituents may be bonded to each other to form a ring, and when a plurality of substituents are present, each substituent may be the same or different, and linked to each other to form a ring. May be formed.

  In the partial structure represented by any one of the general formulas (1) to (4), the substituents represented by R1a to R1i are each a styryl group, an epoxy group, an oxetanyl group, an acrylic group in addition to the alkenyl group described above. And may have a polymerizable group such as a methacryl group.

  Furthermore, the compound containing the partial structure represented by any one of the general formulas (1) to (4) can react with the polymerizable groups or other polymerizable monomers to form a polymer.

  When a plurality of partial structures are present in the polymer, the partial structures represented by any one of the general formulas (1) to (4) may be the same or different.

<Method for Polymerizing Partial Structure Represented by any of General Formulas (1) to (4)>
The polymer (polymer) containing a partial structure represented by any one of the general formulas (1) to (4) is “Revised Polymer Synthesis Chemistry” Chemistry “Polymer Synthesis Experimental Method” Chemistry Dojin “Fourth Edition” It can be synthesized using the method described in Experimental Chemistry Course 28 “Polymer Synthesis” Maruzen et al.

  Preferable polymerization methods include 1) polycondensation, 2) radical polymerization, 3) ionic polymerization, 4) polyaddition, addition condensation, and the like, which can be used depending on the type of polymerizable group.

  The polymer containing the partial structure represented by any one of the general formulas (1) to (4) can be made into a homopolymer using the above method, or can be made into a copolymer combined with a plurality of monomers. It is.

  Hereinafter, specific examples of the compound (also referred to as a metal complex or a metal complex compound) including a partial structure represented by any one of the general formulas (1) to (4) according to the present invention will be shown. It is not limited.

  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 a method such as a reference described in these documents.

  Although the synthesis example of the metal complex based on this invention is shown below, this invention is not limited to these.

  << Synthesis Example: Synthesis of Exemplary Compound A-97 >>

Step 1: Synthesis of complex C A 100 ml four-necked flask was charged with 1.5 g of 2-methylimidazo [1,2-f] phenanthridine, 13 ml of 2-ethoxyethanol, and 3 ml of water, a nitrogen blowing tube, a thermometer, a condenser And set on an oil bath stirrer.

To this, 0.55 g of IrCl ₃ .3H ₂ O and 0.16 g (0.001560 mol) of triethylamine were added, and the mixture was boiled and refluxed at an internal temperature of about 100 ° C. for 6 hours to complete the reaction.

  After completion of the reaction, the reaction mixture was cooled to room temperature, methanol was added, and the precipitated solid was collected by filtration. The obtained solid was thoroughly washed with methanol and dried to obtain 1.37 g (77.0%) of Complex C.

Step 2: Synthesis of Complex D In a 50 ml four-necked flask, 1.0 g (0.0007244 mol) of Complex C, 0.29 g of acetylacetone, 1.0 g of sodium carbonate, and 24 ml of 2-ethoxyethanol were introduced, and nitrogen was blown into the flask. A tube, a thermometer and a condenser were attached and set on an oil bath stirrer.

  The mixture was heated and stirred for 1.5 hours at a nitrogen gas stream inner temperature of around 80 ° C.

  After completion of the reaction, the reaction solution was cooled to room temperature, methanol was added to the reaction solution, and the precipitated crystals were filtered. The crystals were washed with 30 ml of water and 10 ml of MeOH and dried to obtain 0.42 g of complex D (38.5%).

Step 3: Synthesis of Exemplified Compound A-97 In a 50 ml four-necked flask, 0.386 g (0.0005120 mol) of Complex D, 0.357 g of 2-methylimidazo [1,2-f] phenanthridine, glycerin 20 ml was added, and a nitrogen blowing tube, a thermometer, and an air cooling tube were attached and set on an oil bath stirrer. The reaction was completed by heating and stirring for 4.5 hours at an internal temperature of 150 ° C. under nitrogen flow.

  After completion of the reaction, the mixture was cooled to room temperature, methanol was added and dispersed, and the crystals were collected by filtration to obtain 0.38 g of crude crystals.

  The crystals were purified by column chromatography (developing solvent: toluene / ethyl acetate), and the obtained crystals were purified by suspension in a mixed solvent of tetrahydrofuran and ethyl acetate, and 0.3 g (66.6%) of Exemplified Compound A-97 was obtained. )Obtained.

  The structure of the obtained exemplary compound A-97 was confirmed using 1H-NMR (nuclear magnetic resonance spectrum). Measurement conditions, chemical shift of each peak of the obtained spectrum, proton number, etc. are shown below.

¹ H-NMR (400 MHz, tetrahydrofuran-d8)
Measuring apparatus: JEOL JNM-AL400 (400 MHz): manufactured by JEOL Ltd. Spectrum attribution (chemical shift δ, proton number, peak shape)
8.48 (1H, d), 7.93 (1H, d), 7.75 (1H, s), 7.64 (1H, d), 7.54 (1H, t), 7.46 (1H) , T), 6.95 (1H, t), 6.83 (1H, d), 1.85 (3H, s) The emission wavelength in the solution of Exemplified Compound A-97 was 455 nm (emission wavelength) Is measured in 2-methyltetrahydrofuran).

  In the present invention, the emission wavelength of the exemplified compound was measured as follows. First, an absorption spectrum of the exemplary compound is measured, and an absorption maximum wavelength in the range of 300 nm to 350 nm is set as excitation light.

  Using the set excitation light, the emission wavelength is measured with a fluorometer F-4500 (manufactured by Hitachi, Ltd.) while performing nitrogen bubbling.

  In addition, although there is no restriction | limiting in the solvent which can be used, 2-methyltetrahydrofuran, a dichloromethane, etc. are used preferably from a soluble viewpoint of a compound.

Concentration at the time of measurement is preferably are diluted enough, in particular is preferably measured in the range of ^{10 -6 mol / l~10 -4 mol /} l.

  Moreover, there is no restriction | limiting in particular as temperature at the time of measurement, However, Generally, it is preferable that temperature setting of the range of room temperature-77K is performed.

<< Organic Compound Containing Partial Structure Represented by General Formula (5) or (6) >>
The organic compound containing the partial structure represented by the general formula (5) or (6) will be described.

  The organic compound containing the partial structure represented by the general formula (5) or (6) of the present invention has one or more indenoindole groups in the molecule. Since the indenoindole group has higher electron mobility than the carbazole group, when the substituents are almost the same, the overall electron mobility is slightly higher than the compound having one or more carbazolyl groups in the molecule. . However, the electron mobility is not extremely improved like an electron transport material.

  On the other hand, the transition metal complex compound including the partial structure represented by the general formula (1), (2), (3) or (4) of the present invention has improved hole transportability compared to the conventional transition metal complex. For this reason, the combined use of a conventional host compound composed of a plurality of carbazolyl groups cannot achieve a perfect balance between hole transfer and electron transfer, so that sufficient performance cannot be exhibited.

  As a result of investigation of an optimal host compound to be used in combination with a transition metal complex compound containing a partial structure represented by the general formula (1), (2), (3) or (4) of the present invention, By using an organic compound containing a partial structure represented by the general formula (5) or (6) as a host compound, the balance between hole transfer and electron transfer can be perfectly matched, and thereby a specific short wave Light emission was seen, an organic EL device having a high light emission efficiency and a long light emission lifetime could be provided. Furthermore, as an unexpected effect, the initial deterioration at the start of device driving can be greatly reduced, and the dark spot of the light emitting device has also been greatly reduced, thereby providing a useful organic EL device. I was able to.

  Furthermore, the preferable embodiment of the organic compound containing the partial structure represented by General formula (5) or (6) is demonstrated.

  The optimum host compound for use in combination with the transition metal complex compound containing the partial structure represented by the general formula (1), (2), (3), or (4) of the present invention is the above general formula (5). Or it is an organic compound containing the partial structure represented by (6).

In the formula, A ₁ and A ₂ each independently represent a single bond or an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent.

  As the arylene group, a divalent group obtained by removing any hydrogen atom of any aryl group can be used. Examples of the aryl group include a phenyl group, a p-chlorophenyl group, a mesityl group, a tolyl group, Examples include xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, and biphenylyl group.

  As a bivalent heterocyclic group, the bivalent group obtained by remove | excluding the arbitrary hydrogen atoms of arbitrary heterocyclic groups is mentioned. The heterocyclic group may be aromatic or non-aromatic.

  Examples of aromatic heterocyclic groups include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazole-1). -Yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzo Furyl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) Quinoxalinyl group, pyridazinyl group, triazinyl group, Zoriniru group, phthalazinyl group, and the like.

  Examples of the non-aromatic heterocyclic group include a pyrrolidyl group, an imidazolidinyl group, a morpholinyl group, an oxazolidinyl group, a tetrahydrofuranyl group, a tetrahydrothienyl group, and the like.

  Examples of the substituent include 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.), A cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), an alkenyl group (eg, vinyl group, allyl group, etc.), an alkynyl group (eg, ethynyl group, propargyl group, etc.), an aromatic hydrocarbon ring group (aromatic carbon) Also referred to as ring group, aryl group, etc., 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, Zyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazole- 1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl Group, carbazolyl group, carbolinyl group, diazacarbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group , Phthalazinyl group, etc.) Heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group) Etc.), cycloalkoxy groups (eg cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy groups (eg phenoxy group, naphthyloxy group etc.), alkylthio groups (eg methylthio group, ethylthio group, propylthio group, pentylthio group) Hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (example) For example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (For example, 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) Cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy) Group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexyl group) Carbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino , Naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexyl) Aminocarbonyl 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, etc.), sulfinyl group (for example, methylsulfinyl group) , Ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethyl Sulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), Amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group) Group, anilino group, naphthylamino group, 2-pyridylamino group, diphenylamino group, phenylnaphthylamino group, etc.), halogen atom (for example, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (for example, Fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group) , Phenyldiethylsilyl group, etc.), phosphono group and the like. These substituents may be further substituted with the above substituents.

  A plurality of these substituents may be bonded to each other to form a ring, and when a plurality of substituents are present, each substituent may be the same or different, and linked to each other to form a ring. May be formed.

R _{1 to} R ₂₀ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (one or two or more methylene groups not adjacent to the alkyl group are- O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, —C≡C— may be substituted, and one or more The methylene group may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, and the hydrogen atom in the alkyl group is a fluorine atom. A cycloalkyl group having 3 to 20 carbon atoms (one or two or more methylene groups not adjacent to the cycloalkyl group may be -O-, -S-, -CO-,- Replaced by CO-O-, -O-CO-, -CH = CH- And one or two or more methylene groups may be substituted with an optionally substituted arylene group or an optionally substituted divalent heterocyclic group. Or a hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.), An aryl group which may have a substituent or a heterocyclic group which may have a substituent. Adjacent ones may be bonded to form a ring structure.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, etc., and the alkyl group A group in which one or more methylene groups are replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, or Examples thereof include a group in which one or more methylene groups of an alkyl group are substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent. Any hydrogen atom in the alkyl group may be substituted with a fluorine atom.

  Examples of the cycloalkyl group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group and the like, and one or two or more methylene groups not adjacent to the preceding cycloalkyl group are -O-, -S-, A group substituted by -CO-, -CO-O-, -O-CO-, -CH = CH-, or one or more methylene groups of the preceding cycloalkyl group have a substituent; And a group substituted with a divalent heterocyclic group which may have an arylene group or a substituent. Any hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.

  Examples of aryl groups include phenyl, p-chlorophenyl, mesityl, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenanthryl, indenyl, pyrenyl, biphenylyl Etc.

  The heterocyclic group may be aromatic or non-aromatic.

  Examples of aromatic heterocyclic groups include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazole-1). -Yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzo Furyl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) Quinoxalinyl group, pyridazinyl group, triazinyl group, Zoriniru group, phthalazinyl group, and the like.

  Examples of the non-aromatic heterocyclic group include a pyrrolidyl group, an imidazolidinyl group, a morpholinyl group, an oxazolidinyl group, a tetrahydrofuranyl group, a tetrahydrothienyl group, and the like.

  The preferable embodiment of the organic compound containing the partial structure represented by the general formula (5) or (6) of the present invention is a case where the compound is represented by any one of the following general formulas (7) to (12). is there.

  In the formula, m1, m2, n1 and n2 are each an integer of 0 to 6.

  However, m1 + n1 ≦ 6 and m2 + n2 ≦ 6.

  m3, m4, m5, m6, n3, n4, n5 and n6 are each an integer of 1-6. However, m3 + n3 ≦ 6, m4 + n4 ≦ 6, m4 + n4 ≦ 6, m5 + n5 ≦ 6, and m6 + n6 ≦ 6.

X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ are each a single bond, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or It represents an mx + nx valent group selected from an amino group which may have a substituent. Here, x represents any one of 1-6.

  Examples of aryl groups include phenyl, p-chlorophenyl, mesityl, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenanthryl, indenyl, pyrenyl, biphenylyl Etc.

  The heterocyclic group may be aromatic or non-aromatic.

  Examples of aromatic heterocyclic groups include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazole-1). -Yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzo Furyl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) Quinoxalinyl group, pyridazinyl group, triazinyl group, Zoriniru group, phthalazinyl group, and the like.

  Examples of the non-aromatic heterocyclic group include pyrrolidinyl group, imidazolidinyl group, morpholyl group, oxazolidinyl group, tetrahydrofuranyl group, tetrahydrothienyl group and the like.

  As an example of a substituent, the same thing as what was mentioned by description of the said General formula (5) or (6) is mentioned.

A ₁ and A ₂ each independently represent a single bond or an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent. Examples of the arylene group and the divalent heterocyclic group are the same as those described above in the description of the general formula (5) or (6).

A ₃ and A ₄ each independently represent an aryl group which may have a substituent or a heterocyclic group which may have a substituent. Examples of the aryl group or the substituent include the same groups as those described above for X _{1 to} X ₆ .

R _{1 to} R ₂₀ are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (one or two or more methylene groups not adjacent to the alkyl group are- O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, —C≡C— may be substituted, and one or more The methylene group may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, and the hydrogen atom in the alkyl group is a fluorine atom. Which may be substituted.), A cycloalkyl group having 3 to 20 carbon atoms (one or two or more methylene groups not adjacent to the cycloalkyl group are -O-, -S-, -CO-,- CO—O—, —O—CO—, —CH═CH—, One or two or more methylene groups may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent. And a hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.), An aryl group which may have a substituent or a heterocyclic group which may have a substituent. The adjacent ones may be bonded to form a ring structure.

  Examples of the alkyl group, cycloalkyl group, aryl group, and heterocyclic group are the same as those described above in the description of the general formula (5) or (6).

《Molecular weight》
The molecular weight of the organic compound containing the partial structure represented by the general formula (5) or (6) of the present invention is usually 4000 or less, preferably 3000 or less, more preferably 2000 or less, and usually 200 or more, preferably 300 or more, more preferably 400 or more.

  When the molecular weight of the organic compound containing the partial structure represented by the general formula (5) or (6) of the present invention exceeds this upper limit, the sublimation property is remarkably lowered, and an evaporation method is used when producing an electroluminescent device. If it is used, it may interfere with the purification or it may be difficult to purify due to the high molecular weight of impurities. If the lower limit is not reached, the glass transition temperature, melting point, vaporization temperature, etc. will decrease, so the heat resistance will be significantly impaired. There is a risk of being.

<Physical properties>
The organic compound containing a partial structure represented by the general formula (5) or (6) of the present invention usually has a glass transition temperature of 50 ° C. or higher, but when used in an organic electroluminescent device, its heat resistance From this viewpoint, the glass transition temperature is preferably 90 ° C. or higher, and more preferably 110 ° C. or higher. The upper limit of the glass transition temperature is usually about 400 ° C.

  The organic compound containing the partial structure represented by the general formula (5) or (6) of the present invention usually has a vaporization temperature of 800 ° C. or lower under normal pressure, but when used in an organic electroluminescent device, From the viewpoint of the stability of the vapor deposition film forming step, the vaporization temperature is preferably 700 ° C. or lower, and more preferably 600 ° C. or lower. The lower limit of the vaporization temperature is usually about 300 ° C.

  The organic compound containing the partial structure represented by the general formula (5) or (6) of the present invention usually has a melting point of 100 ° C. or higher, but when used in an organic electroluminescent device, its heat resistance viewpoint. Therefore, the melting point is preferably 150 ° C. or higher, and more preferably 200 ° C. or higher. The upper limit of the melting point is usually about 500 ° C.

  Hereinafter, although the specific example of the organic compound containing the partial structure represented by General formula (5) or (6) based on this invention is shown, this invention is not limited to these.

  The indenoindole compound of the present invention can be synthesized with reference to Tetrahedron, 47 (1991) 4383.

  Synthesis Example (Synthesis of Exemplified Compound No. IH-5)

  3. Phenylhydran-1-one 4.17 g (20.0 mmol), phenylhydrazine 2.17 g (20.0 mmol), acetic acid 100 ml, concentrated hydrochloric acid 6.0 ml were placed in a 300 ml three-necked flask, and a nitrogen stream for 10 hours. Stir at room temperature. The reaction solution was poured into 150 ml of cold water, filtered, and the obtained crystals were washed with methanol. The crystals were dissolved in toluene, purified by silica gel column chromatography (eluent: toluene / ethyl acetate: 20/1), recrystallized from toluene, and 10-phenyl-5,10-dihydro-indeno [1,2-b ] 1.93 g (34.3% yield) of indole crystals were obtained.

  Under nitrogen stream, 10-phenyl-5,10-dihydro-indeno [1,2-b] indole 0.42 g (1.5 mmole), m-diiodobenzene 0.23 g (0.70 mmole), t-butoxypotassium 0.19 g (1.65 mmole) and 20 ml of o-xylene were placed in a 100 ml three-necked flask and stirred for 10 minutes under a nitrogen stream to uniformly dissolve soluble components. A solution prepared by dissolving 20 mg of palladium acetate and 45 mg of t-butylphosphine in 10 ml of xylene was slowly dropped therein, and the mixture was stirred for 5 hours while heating under reflux. After completion of the reaction, water was added to the reaction solution and extracted twice with ethyl acetate. The organic layer was washed with water, dried over magnesium sulfate and then dried under reduced pressure, purified by silica gel column chromatography (eluent: toluene), recrystallized from acetone and exemplified Compound No. 0.29 g (yield 65.1%) of crystals of IH-5 were obtained.

MASS analysis confirmed 636.8, which is M ⁺ of this compound.

Moreover, the structure of this compound was confirmed by NMR measurement.
¹ HNMR (CDCl ₃ , 400 MHz)
σ (ppm)
7.90 (t, 1H, J = 8.1 Hz), 7.81 (dd, 2H, J = 8.1, 1.7 Hz), 7.80 (d, 1H, J = 1.7 Hz), 7 .50 (d, 2H, J = 8.2 Hz), 7.40 (d, 2H, J = 8.2 Hz), 7.33 (d, 2H, J = 8.2 Hz), 7.12-7. 32 (m, 20H), 5.10 (s, 2H).

  Other compounds of the present invention can be synthesized similarly.

  Next, the light emitting element, illumination device, and image display device of the present invention will be described.

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

  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 means a phosphorescent quantum yield of phosphorescence emission at a room temperature (25 ° C.) having a mass ratio of 20% or more in the compound contained in the light emitting layer. Is defined as a compound of less than 0.1. 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 of the present invention, an organic compound containing a partial structure represented by the general formula (5) or (6) is preferable, and a known host compound may be used in combination, or a plurality of types may be used in combination. It may be used. 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.

  The light emitting host used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (deposition polymerization property). A light emitting host), or one or more compounds such as the material C may be used.

  Although the specific example of the host compound preferably used for this invention below is shown, this invention is not limited to these.

  As a known host compound that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable.

  Specific examples of known host compounds include compounds described in the following documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

(Luminescent dopant)
The light emitting dopant according to the present invention will be described.

  As the light-emitting dopant according to the present invention, 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. From the viewpoint of obtaining an organic EL device with high luminous efficiency, the light emitting dopant used in the light emitting layer or the light emitting unit of the organic EL device of the present invention (sometimes simply referred to as a light emitting material) contains the above host compound. At the same time, it is preferable to contain a phosphorescent dopant.

(Phosphorescent dopant)
The phosphorescent dopant according to the present invention will be described.

  The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., 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 can be appropriately selected from known materials used for the light emitting layer of the organic EL device.

  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), Rare earth complexes, most preferably iridium compounds.

  The compound used as the phosphorescent dopant according to the present invention is preferably a transition metal complex compound including a partial structure represented by any one of the general formulas (1) to (4) according to the present invention.

  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, an injection layer, a blocking layer, an electron transport layer, and the like used as a constituent layer of the organic EL element of the present invention 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, they are described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL elements and their forefront of industrialization” (issued on November 30, 1998 by NTS Corporation). 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.

  In the hole blocking layer, the carbazole derivative, carboline derivative, diazacarbazole derivative (shown by replacing one of the carbon atoms constituting the carboline ring of the carboline derivative with a nitrogen atom) as the host compound described above. It is preferable to contain.

  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.

  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.

《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 ' Di (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 described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 688 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 cathode side with respect to the light emitting layer 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, or 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.

  Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg, Cu , Ca, Sn, Ga, or Pb can also be used as an 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 and 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, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value 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. In order to further improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, 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 measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less, and is measured by a method according to JIS K 7129-1992. The water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two liquid mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive.

  Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

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

  In the gap between the sealing member and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, etc.), 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.

  It is desirable that the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.

  However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the light emitting surface By condensing in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, 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.

  As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above, but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. In view of the above, film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is preferable in the present invention.

  Examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After these layers are formed, a thin film made of a cathode material is formed thereon by 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.

  Further, it is also possible to reverse the production order and produce the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<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.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

  The structures of the compounds used in the examples are 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 is put in another molybdenum resistance heating boat, 100 mg of FIrpic (IR-12) is put in another resistance heating boat made of molybdenum, and 200 mg of Alq ₃ is put in another resistance heating boat made of molybdenum. Attached.

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.

  Furthermore, the heating boat containing H-1 and FIrpic (IR-12) 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. Thus, a light emitting layer having a thickness of 40 nm was provided. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Furthermore, 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.

Further, the heating boat containing Alq ₃ is energized and heated, and is 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 1-21 >>
In the production of the organic EL element 1-1, the organic EL element 1 was similarly prepared except that H-1 as the host compound of the light emitting layer and FIrpic (IR-12) as the dopant compound were replaced with the compounds shown in Table 1. -2 to 1-21 were produced.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 1-2 to 1-21, 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. 3 is 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).

  4 shows a cross-sectional view of the lighting device. In FIG. 4, 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 extraction quantum efficiency (luminescence 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.

(Half life)
The half-life was evaluated according to the measurement method shown below.

Each organic EL device driven with a constant current at a current giving an initial luminance 1000 cd / ^{m 2,} obtains the time to be 1/2 (500cd / ^{m 2)} of the initial luminance, which was used as a measure of the half-life.

  The half life was expressed as a relative value when the comparative organic EL element 1-1 was set to 100.

(Initial deterioration)
The initial deterioration was evaluated according to the measurement method shown below.

  When the half-life was measured, the time required for the luminance to reach 90% was measured and used as a measure of initial deterioration. The initial deterioration was 100 for the comparative organic EL element 1-1.

The initial deterioration was calculated based on the following formula.
Initial deterioration = (luminance 90% arrival time of organic EL element 1-1) / (luminance 90% arrival time of each element) × 100
That is, the smaller the initial deterioration value is, the smaller the initial deterioration is.

(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. In each element after 10 hours of continuous lighting by visual evaluation by 10 randomly extracted people,
When the number of people who confirmed dark spots is 5 or more ×
When the number of confirmed dark spots is 1-4
When the number of people who confirmed dark spots is 0 ○
It was.

  The above evaluation results are shown in Table 1.

  From Table 1, it can be seen that the organic EL device of the present invention has a higher external extraction quantum efficiency, less initial luminance degradation, and a longer lifetime as compared with the comparative device.

  It can also be seen that the generation of dark spots is suppressed.

Example 2
<Production of full-color display device>
(Production of blue light emitting element)
The organic EL element 1-6 of Example 1 was used as a blue light emitting element.

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

(Production of red light emitting element)
A red light emitting device was produced in the same manner as in the organic EL device 1-1 of Example 1 except that FIrpic 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 a configuration as shown in FIG. In FIG. 2, only the schematic diagram of the display part A of the produced display device is shown.

  That is, it has 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 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 and Production of White Lighting Device-1 >>
The electrode of the transparent electrode substrate of Example 1 was patterned to 50 mm × 50 mm, and α-NPD was deposited thereon with a thickness of 25 nm as a hole injection / transport layer in the same manner as in Example 1; The heating boat containing 3 and the boat containing Exemplified Compound A-97 and the boat containing Ir-9 were energized independently, and Illuminating Host IH-3 and Illustrative Compound A-97 as the luminescent dopant, And the vapor deposition rate of Ir-9 was adjusted to 100: 5: 0.6, vapor deposition was performed so as to have a thickness of 30 nm, and a light emitting layer was provided.

Next, 10 nm of BAlq was deposited to provide a hole blocking layer. Further, Alq ₃ was formed at 40 nm to provide an electron transport layer.

  Next, as in Example 1, a square perforated mask having the same shape as the transparent electrode made of stainless steel was placed on the electron transport layer, and lithium fluoride 0.5 nm as the cathode buffer layer and aluminum 150 nm as the cathode. Vapor deposition and film formation were performed.

  This element was provided with a sealing can having the same method and the same structure as in Example 1, and a flat lamp as shown in FIGS. 3 and 4 was produced. When this flat lamp was energized, almost white light was obtained, and it was found that it could be used as a lighting device.

Example 4
<< Production of White Light Emitting Element and White Lighting Device-2 >>
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 prepared by dissolving IH-88 (60 mg), F-9 (3.0 mg), and Ir-14 (3.0 mg) in 6 ml of toluene, the solution was prepared by spin coating at 1000 rpm for 30 seconds. Filmed. 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.

  Furthermore, a film in which compound F (20 mg) was 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.

  This element was provided with a sealing can having the same method and the same structure as in Example 1, and a flat lamp as shown in FIGS. 3 and 4 was produced.

  When this flat lamp was energized, almost white light was obtained, and it was found that it could be used as a lighting device.

Example 5
<< Production of Organic EL Element 5-1 >>
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, using a solution obtained by dissolving Compound E (60 mg) and FIrpic (3.0 mg) in 6 ml of toluene, a film was formed by a spin coating method at 1000 rpm for 30 seconds to form 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 pressure in the vacuum tank was reduced to 4 × ¹⁰ -4 Pa, and heated by supplying an electric current to the boat containing BAlq, it is deposited on the light emitting layer at a deposition rate of 0.1 nm / sec, further thickness 40nm The electron 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 5-2 to 5-10 >>
In the production of the organic EL element 5-1, the organic EL elements 5-2 to 10 were produced in the same manner except that the compound E as the host compound of the light emitting layer and FIrpic as the dopant compound were replaced with the compounds shown in Table 2. did.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 5-1 to 5-10, 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. 3 is 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).

  4 shows a cross-sectional view of the lighting device. In FIG. 4, 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 5-1 as 100.

(Half life)
The half-life was evaluated according to the measurement method shown below.

Each organic EL device driven with a constant current at a current giving an initial luminance 1000 cd / ^{m 2,} obtains the time to be 1/2 (500cd / ^{m 2)} of the initial luminance, which was used as a measure of the half-life. The half life was expressed as a relative value with the comparative organic EL element 1-1 of Example 1 as 100.

(Initial deterioration)
The initial deterioration was evaluated according to the measurement method shown below.

  At the time of measuring the half-life, a time for 90% of the initial luminance was obtained and used as a measure of initial deterioration. In addition, initial stage deterioration was represented by the relative value which sets the comparison organic EL element 1-1 of Example 1 to 100. The smaller the initial deterioration value, the smaller the initial deterioration.

(Dark spot)
The light emitting surface when the organic EL element was continuously lit under a constant current condition of ^2.5 mA / cm ² at room temperature was visually evaluated. By visual evaluation by 10 randomly selected people,
When the number of people who confirmed dark spots is 5 or more ×
When the number of confirmed dark spots is 1-4
When the number of people who confirmed dark spots is 0 ○
It was.

  The above evaluation results are shown in Table 2.

  From Table 2, it can be seen that the organic EL device of the present invention has a higher external extraction quantum efficiency, less initial luminance degradation, and a longer lifetime as compared with the comparative device. It can also be seen that the generation of dark spots is suppressed.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line A Display part B Control part 101 Organic EL element 107 Glass substrate with a transparent electrode 106 Organic EL layer 105 Cathode 102 Glass cover 108 Nitrogen gas 109 Water catching agent

Claims (15)

In an organic electroluminescence device including at least one light emitting layer sandwiched between an anode and a cathode, the light emitting layer is represented by the following general formula (1), (2), (3), or (4) Organic electroluminescence comprising an organic layer containing at least one compound containing a partial structure and containing at least one compound containing a partial structure represented by the following general formula (5) or (6) element.

[In formula, E1a-E1q represents a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and the skeleton comprised by E1a-E1q has a total of 18 (pi) electrons. E1a and E1p are different from each other and represent a carbon atom or a nitrogen atom. R1a to R1i each represents a hydrogen atom or a substituent. M represents a group 8-10 transition metal element in the periodic table. ]

[Wherein, A ₁ and A ₂ each independently represent a single bond or an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent.
R _{1 to} R ₂₀ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (one or two or more methylene groups not adjacent to the alkyl group are- O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, —C≡C— may be substituted, and one or more The methylene group may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, and the hydrogen atom in the alkyl group is a fluorine atom. A cycloalkyl group having 3 to 20 carbon atoms (one or two or more methylene groups not adjacent to the cycloalkyl group may be -O-, -S-, -CO-,- Replaced by CO-O-, -O-CO-, -CH = CH- And one or two or more methylene groups may be substituted with an optionally substituted arylene group or an optionally substituted divalent heterocyclic group. Or a hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.), An aryl group which may have a substituent or a heterocyclic group which may have a substituent. Adjacent ones may be bonded to form a ring structure. ] The organic electroluminescence according to claim 1, wherein the compound containing the partial structure represented by the general formula (5) or (6) is represented by any one of the general formulas (7) to (12). element.

[Wherein, m1, m2, n1, and n2 are each an integer of 0-6.
However, m1 + n1 ≦ 6 and m2 + n2 ≦ 6.
m3, m4, m5, m6, n3, n4, n5 and n6 are each an integer of 1-6. However, m3 + n3 ≦ 6, m4 + n4 ≦ 6, m4 + n4 ≦ 6, m5 + n5 ≦ 6, and m6 + n6 ≦ 6.
X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ are each a single bond, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or It represents an mx + nx valent group selected from an amino group which may have a substituent. Here, x represents any one of 1-6.
A ₁ and A ₂ each independently represent a single bond or an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent.
A ₃ and A ₄ each independently represent a single bond or an aryl group which may have a substituent or a heterocyclic group which may have a substituent.
R _{1 to} R ₂₀ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms (one or two or more methylene groups not adjacent to the alkyl group are- O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—, —C≡C— may be substituted, and one or more The methylene group may be substituted with an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, and the hydrogen atom in the alkyl group is a fluorine atom. A cycloalkyl group having 3 to 20 carbon atoms (one or two or more methylene groups not adjacent to the cycloalkyl group may be -O-, -S-, -CO-,- Replaced by CO-O-, -O-CO-, -CH = CH- And one or two or more methylene groups may be substituted with an optionally substituted arylene group or an optionally substituted divalent heterocyclic group. Or a hydrogen atom in the cycloalkyl group may be substituted with a fluorine atom.), An aryl group which may have a substituent or a heterocyclic group which may have a substituent. Adjacent ones may be bonded to form a ring structure. ] 3. The organic electroluminescence according to claim 2, wherein the linking group represented by X _{1 to} X ₆ in the general formulas (7) to (12) is an aromatic ring group or an aromatic heterocyclic group. element. In the general formulas (7) to (12), the linking group represented by X _{1 to} X ₆ is a phenyl group, a biphenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a fluorenyl group, a pyrenyl group, or an anthracenyl group. 4. The organic electroluminescence device according to claim 2, wherein the organic electroluminescence device is a divalent group formed by removing one hydrogen atom from the group, and a group comprising a combination thereof. The organic electroluminescence device according to any one of claims 2 to 4, wherein a glass transition temperature of the compounds represented by the general formulas (7) to (12) is 100 ° C or higher. That at least one of the substituents represented by R _{1 to} R ₁₀ or R _{1 to} R ₂₀ in the compounds represented by the general formulas (7) to (12) is a polymerizable substituent. The organic electroluminescence element according to claim 2, wherein the organic electroluminescence element is characterized. The organic electroluminescent element according to claim 1, wherein the ring composed of E1a to E1e is an imidazole ring or a pyrazole ring. 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 (4), and the organic layer was formed using a wet process The organic electroluminescent element according to any one of claims 1 to 7, wherein It has an organic layer containing at least one compound represented by any one of the general formulas (7) to (12) as a constituent layer, and the organic layer is formed using a wet process. The organic electroluminescent element according to any one of claims 2 to 8. The organic layer containing at least one compound represented by any one of the general formulas (7) to (12) as a constituent layer is a light emitting layer. The organic electroluminescent element according to item. The organic layer containing at least one polymer having a partial structure of the compound represented by any one of the general formulas (7) to (12). The organic electroluminescent element of description. 12. The polymer according to claim 1, comprising at least one polymer having a partial structure of a compound including the partial structure represented by any one of the general formulas (1) to (4). The organic electroluminescent element according to item. The organic electroluminescent element according to claim 1, wherein M is platinum or iridium. A display device comprising the organic electroluminescence element according to claim 1. An illuminating device comprising the organic electroluminescent element according to claim 1.

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