JP5659478B2 - Organic electroluminescence element, lighting device and display device - Google Patents

Description

  The present invention relates to an organic electroluminescence element, and an illumination device and a display device using the same.

  Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (hereinafter abbreviated as ELD). Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter abbreviated 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 element has a configuration in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer to recombine excitons. This is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when this 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 is a thin-film type complete solid-state device, and thus has been attracting attention from the viewpoints of space saving and portability.

  As the development of organic EL devices for practical use, since Princeton University has reported on organic EL devices using phosphorescence emission from excited triplets (for example, see Non-Patent Document 1), phosphorescence at room temperature has been made. Research on the materials shown has been active (see, for example, Patent Document 1 and Non-Patent Document 2).

  Furthermore, the recently discovered organic EL element using phosphorescence can in principle achieve a luminous efficiency about four times that of organic EL elements using fluorescence emission. Research and development of light-emitting element layers and electrodes are being conducted all over the world, including material development. For example, many compounds have been studied focusing on heavy metal complexes such as iridium complexes. (See Patent Document 3).

  The proposed method is an extremely high potential method, but the organic EL device using phosphorescence emission is greatly different from the organic EL device using fluorescence emission, and a method for controlling the position of the emission center. In particular, how to perform recombination inside the light emitting layer to stably emit light is an important technical issue in capturing the efficiency and life of the organic EL element.

  In recent years, multilayer stacked devices having a hole transport layer (located on the anode side of the light emitting layer) and an electron transport layer (located on the cathode side of the light emitting layer) adjacent to the light emitting layer are well known. (For example, refer to Patent Document 2).

  In particular, when utilizing blue phosphorescence, since the blue phosphorescent material itself has a high T1 (minimum excited triplet energy), development of peripheral materials and precise control of the emission center are strongly demanded.

  In recent years, in a light emitting layer of an organic EL element using a phosphorescent light emitting material, a technique using a dibenzothiophene derivative or a dibenzofuran derivative as a hole injection component or a light emitting component (see, for example, Patent Documents 2, 3, and 9), A technique using a dibenzothiophene derivative as a host material (see, for example, Patent Document 4) is disclosed. Moreover, the technique using the compound containing a fluorene derivative as a host material is disclosed (for example, refer patent documents 5 and 6 and nonpatent literature 4). A technique using a compound containing a fluorene derivative as an electron transport material is disclosed (for example, see Patent Documents 7 and 8).

  However, it is still insufficient from the viewpoint of providing an organic EL device with high luminous efficiency, low driving voltage, excellent heat resistance, raw storage stability and long life, and further solutions are being sought. ing.

  On the other hand, because of demands for large area, low cost, and high productivity, there is a great expectation for a wet method (also called a wet process), and it is possible to form a film at a lower temperature than film formation in a vacuum process. There is great expectation from the viewpoint of reducing damage to the lower organic layer and improving luminous efficiency and device lifetime.

  However, in order to realize wet film formation in an organic EL element using blue phosphorescence, particularly a host material contained in the light emitting layer and an electron transport material laminated on the light emitting layer are problems, which are practically used. In view of the above, it has been found that the currently known host materials and electron transport materials are insufficient in terms of solubility in solvents, solution stability, driving voltage, etc., and further development of improved technology is essential. did.

US Pat. No. 6,097,147 JP 2005-112765 A International Publication No. 2007/069569 JP 2007-126403 A Japanese Patent Laid-Open No. 2003-77664 JP 2008-60379 A International Publication No. 2008/069586 JP 2008-208065 A US 2009 / 167,162

M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) S. Lamansky et al. , J .; Am. Chem. Soc. 123, 4304 (2001) Shanghui Ye et al. , Chemistry of Materials, Vol. 21, No. 7, pp. 1333-1342 (2009)

  The present invention has been made in view of the above problems, and an object thereof is to provide an organic electroluminescence element having high luminous efficiency, a low driving voltage, and a long lifetime, and an illumination device and a display device using the organic electroluminescence element. There is to do.

  The above object of the present invention is achieved by the following configurations.

  1. In an organic electroluminescence device having a configuration in which a plurality of organic compound layers are sandwiched between an anode and a cathode, at least one of the organic compound layers contains a compound represented by the following general formula (1) An organic electroluminescence device characterized by the above.

[Wherein, X represents -O- or -S-. R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ each represents a hydrogen atom or a substituent, and at least one of R ₂ and R ₅ may be substituted, an alkyl group, a cycloalkyl group , Phenyl group, naphthyl group, fluorenyl group, aromatic heterocyclic group, aryloxycarbonyl group, alkylsulfonyl group or cyano group . Y ₁ and Y ₂ each represent a hydrogen atom, a substituent, or a group represented by the following general formula (A), and at least one of Y ₁ and Y ₂ is a group represented by the following general formula (A) It is. ]

[Wherein, L represents a divalent linking group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. n represents 0 or an integer of 1 to 3, and when n is 2 or more, the plurality of L may be the same or different. * Represents a linking site with the general formula (1). Ar represents a group represented by the following general formula (B). ]

[Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , R ₁₉ each represents a hydrogen atom or a substituent. * Represents a linking site with L in the general formula (A). ]
2. _2. The organic electroluminescent device according to 1 above, wherein Y ₁ and Y ₂ in the general formula (1) are both groups represented by the general formula (A).

  3. 3. The organic electroluminescence device as described in 1 or 2 above, wherein n in the general formula (A) is 0.

4). Any one of the substituents represented by R ₂ and R ₅ in the general formula (1) is a group represented by the following general formula (C): The organic electroluminescent element of description.

[Wherein, X ₀ represents —C (R ₂₁ ) (R ₂₂ ) —, —N (R ₂₃ ) —, —O— or —S—, and E ₁ to E ₈ each represents —C (R ₂₄ ) = or -N =, and R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each represents a hydrogen atom or a substituent. * Represents a linking site with the general formula (1). ]
5. 5. The organic electroluminescence device as described in 4 above, wherein the group represented by the general formula (C) is a group represented by the following general formula (C-1).

[Wherein, X ₀ represents —C (R ₂₁ ) (R ₂₂ ) —, —N (R ₂₃ ) —, —O— or —S—, and E ₁ to E ₈ each represents —C (R ₂₄ R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each represent a hydrogen atom or a substituent. * Represents a linking site with the general formula (1). ]
6). 6. The organic electroluminescence device according to any one of 1 to 5, wherein the compound represented by the general formula (1) is contained in a light emitting layer.

  7). 7. The organic electroluminescent element according to 6 above, wherein the light emitting layer contains a phosphorescent compound.

  8). Any one of the organic compound layers is an electron transport layer, and the compound represented by the general formula (1) is contained in the electron transport layer. The organic electroluminescent element of description.

  9. 9. The layer according to any one of 1 to 8, wherein the layer containing the compound represented by the general formula (1) is formed through a step of forming a film by a wet method (wet process). Organic electroluminescence element.

  10. 10. The organic electroluminescence device according to any one of 1 to 9, which emits white light.

  11. 11. An illumination device comprising the organic electroluminescence element according to any one of 1 to 10 above.

  12 11. A display device comprising the organic electroluminescent element according to any one of 1 to 10 above.

  According to the present invention, it was possible to provide an organic electroluminescence element having high luminous efficiency, a low driving voltage, and a long lifetime, and an illumination device and a display device using the organic electroluminescence element.

It is the schematic diagram which showed an example of the structure of the display apparatus comprised from an organic EL element. 3 is a schematic diagram illustrating a configuration of a display unit A. FIG. It is a schematic diagram which shows an example of a pixel. It is a schematic diagram which shows an example of a passive matrix type full color display apparatus. It is the schematic which shows an example of the illuminating device which comprised the organic EL element of this invention. It is sectional drawing which shows an example of the illuminating device which comprised the organic EL element of this invention. It is a schematic block diagram which shows an example of an organic electroluminescent full color display apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the present inventor was able to obtain the knowledge described below, and as a result of performing molecular design based on those knowledge, it was represented by the general formula (1) according to the present invention. By using the compound represented by the general formula (1) according to the present invention in at least one of the organic compound layers of the organic electroluminescence element (organic EL element), a low driving voltage and It has been found that an organic EL device having a high luminous efficiency and a long lifetime can be obtained, and the present invention has been achieved.

  Since fluorene derivatives have high carrier transport properties, they have been conventionally used for host materials and electron transport materials. However, as a result of studies by the present inventors, it has been found that when a compound composed only of a fluorene ring and an aromatic hydrocarbon ring is used, the driving voltage of the organic EL element tends to increase.

  On the other hand, a derivative composed of a fluorene ring and another aromatic heterocycle, such as a combination of only a single ring such as a pyridine ring or an imidazole ring, tends to decrease the Tg of the compound and also tends to increase the driving voltage. Turned out to be. However, it has also been found that the driving voltage tends to be low in an organic EL element using a derivative in which a fluorene ring is linked at the 2-position or 4-position of a dibenzofuran ring or dibenzothiophene ring.

  Furthermore, when the connection position of the fluorene ring to the dibenzofuran ring and the dibenzothiophene ring was continuously examined, the 4-position of the dibenzofuran ring and the dibenzothiophene ring as in the compound represented by the general formula (1) according to the present invention. Derivatives in which the 6-position and the 9-position of the fluorene ring are bonded directly or via a linking group and a substituent is introduced at the 2-position or 8-position of the dibenzofuran ring or dibenzothiophene ring have high solubility. Improved. As a result, it has become possible to provide a material having suitability for the wet process.

  Hereafter, the detail of each component of the organic electroluminescent element of this invention is demonstrated. It should be noted that the organic EL element is composed of an anode, a cathode, and constituent layers sandwiched between the anode and the cathode (such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer). Details of the organic layer and the like will be described later.

<< Compound Represented by Formula (1) >>
First, the detail of the compound represented by General formula (1) based on this invention is demonstrated.

In the general formula (1), X represents —O— or —S—. R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ each represents a hydrogen atom or a substituent, and at least one of R ₂ and R ₅ represents a substituent. Y ₁ and Y ₂ each represent a hydrogen atom, a substituent, or a group represented by the general formula (A), and at least one of Y ₁ and Y ₂ is a group represented by the following general formula (A) It is.

In the general formula (1), both Y ₁ and Y ₂ are preferably a group represented by the general formula (A). In the general formula (1), when only one of Y ₁ and Y ₂ is a group represented by the general formula (A) and the other is represented by a substituent, the substituent is R described later. Specific examples of the substituents mentioned in ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ can be given.

  In the general formula (A), L represents a divalent linking group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring.

  Examples of the divalent linking group derived from the aromatic hydrocarbon ring include, for example, o-phenylene group, m-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, and naphthylnaphthalene. Diyl group, biphenyldiyl group (for example, [1,1′-biphenyl] -4,4′-diyl group, 3,3′-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terphenyldiyl group, Quaterphenyldiyl group, kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group, etc., preferably o-phenylene group, an m-phenylene group and a p-phenylene group;

  Examples of the divalent linking group derived from the aromatic heterocycle include, for example, a carbazole ring, a carboline ring, a diazacarbazole ring (also called a monoazacarboline ring, in which one of the carbon atoms constituting the carboline ring is replaced with a nitrogen atom. A triazole ring, imidazole ring, pyrazole ring, pyrrole ring, pyridine ring, pyrazine ring, quinoxaline ring, thiophene ring, thiazole ring, silole ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring A divalent group derived from the group consisting of an indole ring, a thienothiophene ring, a dibenzocarbazole ring, a benzodithiophene ring, a phenanthroline ring, a chalcogen atom such as oxygen or sulfur, and a mixture of three or more rings A group derived from a fused aromatic heterocycle, etc. The condensed aromatic heterocycle formed by condensing is preferably an aromatic heterofused ring containing a heteroatom selected from N, O and S as an element constituting the condensed ring. Includes an acridine ring, a benzoquinoline ring, a carbazole ring, a phenazine ring, a phenanthridine ring, a phenanthroline ring, a carboline ring, a cyclazine ring, a kindrin ring, a tepenidine ring, a quinindrine ring, a triphenodithiazine ring, a triphenodioxazine ring, Phenanthrazine ring, anthrazine ring, perimidine ring, diazacarbazole ring (representing any one of carbon atoms constituting carboline ring replaced by nitrogen atom), phenanthroline ring, dibenzofuran ring, dibenzothiophene ring, naphthofuran ring , Naphthothiophene ring, benzodifuran ring Benzodithiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, thiophanthrene ring (naphthothiophene ring) Is mentioned.

In the general formula (A), each of the divalent linking groups represented by L is further represented by R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ in the general formula (1). You may have the substituent of.

  In general formula (A), n represents 0 or an integer of 1 to 3, and when n is 2 or more, a plurality of L may be the same or different. Preferably n is 0 or 1, more preferably n is 0. * Represents a linking site with the general formula (1).

In the general formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ each represent a hydrogen atom or a substituent, but R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ represents a substituent, 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). Group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, propargyl group, etc.) Etc.), aromatic hydrocarbon groups (also referred to as aromatic hydrocarbon ring groups, aromatic carbocyclic groups, aryl groups, etc.), for example, phenyl groups, p-chlorophenyl groups, Til, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenanthryl, indenyl, pyrenyl, biphenylyl, etc.), aromatic heterocyclic groups (eg, pyridyl, 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 , Carborinyl group, Diazaca A bazolyl group (in which one of carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a quinoxalinyl group, a pyridazinyl group, a triazinyl group, a quinazolinyl group, a phthalazinyl group, etc.), a 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 group (For example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (for example, phenoxy group, naphthyloxy group, etc.), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octyl group) Ruthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxy) Carbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylamino) Sulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminos Sulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2 -Ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group) Group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbo group) Ruamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group) , Methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylamino Carbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pliers) Ureido 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, ethylsulfonyl 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, anilino group, Naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, penta) Fluorophenyl 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.

The substituent represented by R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ is preferably an alkyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkoxy group.

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

In the general formula (1), Ar represents a group represented by the general formula (B). In the general formula (B), R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , R ₁₉ each represents a hydrogen atom or a substituent. * Represents a linking site with L in the general formula (A). In the general formula (B), when R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , R ₁₉ represent a substituent, the substituent is represented by the general formula (1) ), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ can be given as specific examples.

In general formula (1), at least one of R ₂ or R ₅ represents a substituent. R ₂ or R ₅ is preferably a group represented by the general formula (C).

In the general formula (C), X ₀ represents —C (R ₂₁ ) (R ₂₂ ) —, —N (R ₂₃ ) —, —O— or —S—, and E ₁ to E ₈ each represents —C (R ₂₄ ) ═ or —N═ is represented, and R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each represent a hydrogen atom or a substituent. Examples of the substituent represented by R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ include the substitution represented by R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ in the general formula (1). The same substituents as the group can be mentioned. * Represents a linking site with the general formula (1).

  Furthermore, the group represented by the general formula (C) is preferably a group represented by the general formula (C-1).

In the general formula (C-1), X ₀ represents —C (R ₂₁ ) (R ₂₂ ) —, —N (R ₂₃ ) —, —O— or —S—, and E ₁ to E ₈ represent Each represents —C (R ₂₄ ), and R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each represent a hydrogen atom or a substituent. Examples of the substituent represented by R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ include the substitution represented by R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ in the general formula (1). The same substituents as the group can be mentioned. * Represents a linking site with the general formula (1).

  Furthermore, the general formula (C-1) is represented by the following general formula (C-2), (C-3), (C-4), (C-5), (C-6) or (C-7). It is preferable that it is group represented by these.

In the general formula (C-2), R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ , R ₇₈ and R ₇₉ each represent a hydrogen atom or a substituent. When R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ , R ₇₈ and R ₇₉ represent a substituent, examples of the substituent include R ₁ , R ₂ and R _{3 in the} general formula (1). , R ₄ , R ₅ and R ₆ can be exemplified by the same substituents as those represented by R ₆ . * Represents a linking site with the general formula (1).

In the general formula (C-3), R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ , R ₇₇ and R ₇₈ each represent a hydrogen atom or a substituent. When R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ , R ₇₇ and R ₇₈ represent a substituent, examples of the substituent include R ₁ , R ₂ , R _{3 in the} general formula (1). , R ₄ , R ₅ and R ₆ can be exemplified by the same substituents as those represented by R ₆ . * Represents a linking site with the general formula (1).

In the general formula (C-4), R ₉₁ , R ₉₂ , R ₉₃ , R ₉₄ , R ₉₅ , R ₉₆ and R ₉₈ each represent a hydrogen atom or a substituent. When R ₉₁ , R ₉₂ , R ₉₃ , R ₉₄ , R ₉₅ , R ₉₆ and R ₉₈ represent a substituent, examples of the substituent include R ₁ , R ₂ , R ₃ and R _{4 in the} general formula (1). , R ₅ , R ₆ and the same substituents as the substituents represented by R ₆ can be exemplified. * Represents a linking site with the general formula (1).

In the above general formula (C-5), R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , R ₁₀₄ , R ₁₀₅ , R ₁₀₆ and R ₁₀₈ each represent a hydrogen atom or a substituent. When R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , R ₁₀₄ , R ₁₀₅ , R _106, and R ₁₀₈ represent a substituent, examples of the substituent include R ₁ , R ₂ , R ₃ , R _{4 in the} general formula (1). , R ₅ , R ₆ and the same substituents as the substituents represented by R ₆ can be exemplified. * Represents a linking site with the general formula (1).

In the general formula (C-6), R ₁₁₁ , R ₁₁₂ , R ₁₁₃ , R ₁₁₄ , R ₁₁₅ , R ₁₁₇ , R ₁₁₈ , R _a and R _b each represent a hydrogen atom or a substituent. When R ₁₁₁ , R ₁₁₂ , R ₁₁₃ , R ₁₁₄ , R ₁₁₅ , R ₁₁₇ , R ₁₁₈ , R _a and R _b represent a substituent, examples of the substituent include R ₁ and R _{2 in the} general formula (1). , R ₃ , R ₄ , R ₅ and R ₆ can be exemplified by the same substituents as those represented by R ₆ . * Represents a linking site with the general formula (1).

In the general formula (C-7), R ₁₁₁ , R ₁₁₂ , R ₁₁₃ , R ₁₁₄ , R ₁₁₅ , R ₁₁₆ , R ₁₁₇ , R _118, and R _a each represents a hydrogen atom or a substituent. When R ₁₁₁ , R ₁₁₂ , R ₁₁₃ , R ₁₁₄ , R ₁₁₅ , R ₁₁₆ , R ₁₁₇ , R ₁₁₈ and R _a represent a substituent, examples of the substituent include R ₁ and R _{2 in the} general formula (1). , R ₃ , R ₄ , R ₅ and R ₆ can be exemplified by the same substituents as those represented by R ₆ . * Represents a linking site with the general formula (1).

  Hereinafter, although the specific example of a compound represented by General formula (1) based on this invention is shown, this invention is not limited to these.

  The compound represented by the general formula (1) according to the present invention is described in, for example, International Publication No. 07/111176, Chem. Mater. 2008, 20, 5951, Laboratory Chemistry Lecture 5th Edition (Edited by Chemical Society of Japan), Non-Patent Document 4 (Shanghui Ye et al., Chemistry of Materials, Vol. 21, No. 7, pp. 1333-1342 (2009)), etc. It can synthesize | combine with reference to the well-known method of description to description. Below, the synthesis example of a typical compound is shown.

  << Synthesis of Exemplified Compound 1 >>

(Step 1: Synthesis of Intermediate 1)
Under a nitrogen atmosphere, 0.5 mol of 2,8-dimethyldibenzofuran was mixed with 800 ml of dehydrated tetrahydrofuran (hereinafter abbreviated as THF), cooled to −70 ° C., and 1.6 M / L of n-butyllithium. N-hexane solution (0.5 mol) was slowly added dropwise and stirred for 3 hours. Next, 0.5 mol of 1,2-dibromoethane was added dropwise, and then the temperature was raised slowly and stirred at room temperature for 5 hours. Toluene was added to the reaction solution, washed three times with distilled water, the organic phase was dried over anhydrous magnesium sulfate, the solvent of the organic layer was distilled off under reduced pressure, and the residue was purified by silica gel flash chromatography to obtain an intermediate. 1 was obtained with a yield of 70%. The obtained intermediate 1 was confirmed to have the above structure by nuclear magnetic resonance spectrum and mass spectrum.

(Step 2: Synthesis of Intermediate 2)
Under a nitrogen atmosphere, 0.1 mol of intermediate 1 was mixed with 100 ml of dehydrated THF, cooled to -70 ° C, and then a 1.6 mol / L n-hexane solution of n-butyllithium (0.1 Mol) was slowly added dropwise and stirred for 1 hour. Next, 0.07 mol of fluorenone was mixed with 100 ml of dehydrated THF and added dropwise to the reaction solution. Thereafter, the temperature was slowly raised, and the mixture was stirred at room temperature for 2 hours, and diluted hydrochloric acid was added. Toluene was added to the reaction solution, washed 3 times with distilled water, the organic phase was dried over anhydrous magnesium sulfate, the solvent of the organic phase was distilled off under reduced pressure, and the residue was purified by silica gel flash chromatography. Body 2 was obtained with a yield of 60%.

(Step 3: Synthesis of Exemplary Compound 1)
Under a nitrogen atmosphere, 57% hydroiodic acid (0.07 mol) was slowly added dropwise to a solution in which 0.02 mol of Intermediate 2 was mixed with 150 ml of acetic acid, and the mixture was heated and stirred for 2 hours. Thereafter, the reaction water was poured into water and sodium bicarbonate was added. Toluene was added to the reaction solution, washed 3 times with distilled water, the organic phase was dried over anhydrous magnesium sulfate, the solvent of the organic phase was distilled off under reduced pressure, and the residue was purified by silica gel flash chromatography. 1 was obtained.

  The obtained Exemplified Compound 1 was confirmed to have the above structure by nuclear magnetic resonance spectrum and mass spectrum.

<< Constituent layers of organic EL elements >>
Subsequently, the detail of each structural layer of the organic EL element of this invention is demonstrated.

  In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode (vi) anode // hole transport layer / anode buffer layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (vii) anode / anode Buffer layer / hole transport layer / light emitting layer / electron transport layer / cathode buffer layer / cathode In the organic EL device of the present invention, the light emitting layer may form a unit to form a light emitting layer unit. Further, a non-light emitting intermediate layer may be provided between the light emitting layers, and the intermediate layer may include a charge generation layer. The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

《Electron transport layer》
The electron transport layer in the present invention 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.

  An electron transport material (including a hole blocking material and an electron injection material) used for the electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. As a constituent material of the layer, any one of conventionally known compounds can be selected and used.

  Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, And azacarbazole derivatives including carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, carboline derivatives, and the like.

  Here, the azacarbazole derivative refers to one in which one or more carbon atoms constituting the carbazole ring are replaced with a nitrogen atom.

  Furthermore, in the oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material.

  It is also possible to use a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.

  In addition, metal-free or metal phthalocyanine, or those having the terminal substituted with an alkyl group or a sulfonic acid group can also be used as the electron transport material.

  Further, similarly to the hole injection layer and the hole transport layer, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is made of an electron transport material such as a vacuum deposition method, a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, or a spraying method. It is preferable to form the film by a coating method, a curtain coating method, an LB method (Langmuir-Blodget Langmuir Brodgett method, etc.).

  The method for forming the constituent layers of the organic EL element will be described in detail in the method for manufacturing the organic EL element described later.

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5000 nm, 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.

  Hereinafter, although the specific example of the conventionally well-known compound (electron transport material) preferably used for formation of the electron carrying layer of the organic EL element of this invention is given, this invention is not limited to these.

  Particularly preferred as the electron transport material of the organic EL device of the present invention is the compound represented by the general formula (1) according to the present invention described above, and specific examples thereof include the exemplified compounds 1 to 100. Can do.

<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 5 nm to 100 nm.

  For the production of the light emitting layer, a light emitting dopant or host compound described later is used, for example, a vacuum deposition method, a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, An ink-jet method, a printing method, a spray coating method, a curtain coating method, an LB method (a Langmuir-Blodgett method and the like can be used)) and the like can be formed. When using the compound of this invention for a light emitting layer, producing by a wet process is preferable.

  The light emitting layer of the organic EL device of the present invention contains a light emitting dopant (phosphorescent dopant (also referred to as phosphorescent dopant, phosphorescent dopant group) or fluorescent dopant) compound and a light emitting host compound. Is preferred.

(Luminescent dopant compound)
Hereinafter, the luminescent dopant compound (also referred to as a luminescent dopant) will be described.

  As the light-emitting dopant, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used.

(Phosphorescent dopant (also called phosphorescent dopant))
Next, the phosphorescent dopant will be described.

  The phosphorescent dopant compound applicable to the present invention is a compound in which light emission from an excited triplet is observed, specifically a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield. The phosphorescence quantum yield is preferably 0.1 or more, although it is defined as a compound of 0.01 or more at 25 ° C.

  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 quantum yield (0.01 or more) should just be achieved in any solvent as a phosphorescence dopant.

  There are two types of phosphorescent dopants based on the principle of light emission. One is the recombination of carriers on the host compound to which carriers are transported, and the excited state of the luminescent host compound is generated. Is transferred to the phosphorescent dopant to obtain light emission from the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, and carrier recombination occurs on the phosphorescent dopant, and the phosphorescent dopant compound However, in any of the methods, the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

  Moreover, you may use together the compound etc. which are described in the following patent gazettes in the light emitting layer which concerns on this invention. For example, International Publication No. 00/70655 pamphlet, Japanese Patent Application Laid-Open No. 2002-280178, Japanese Patent Application Laid-Open No. 2001-181616, Japanese Patent Application Laid-Open No. 2002-280179, Japanese Patent Application Laid-Open No. 2001-181617, and Japanese Patent Application Laid-Open No. 2002-280180. JP, 2001-247859, JP, 2002-299060, JP, 2001-313178, JP, 2002-302671, JP, 2001-345183, JP, 2002-324679, International, Publication No. 02/15645, JP 2002-332291 A, JP 2002-50484 A, JP 2002-332292 A, JP 2002-83684 A, JP 2002-540572 A, JP 2002-117978, JP 2002-338588, JP 2002-170684, JP 2002-352960, WO 01/93642, JP 2002-50483, JP 2002-1000047, JP JP 2002-173684 A, JP 2002-359082 A, JP 2002-17584 A, JP 2002-363552 A, JP 2002-184582 A, JP 2003-7469 A, Special Table 2002. No. 525808, JP 2003-7471, JP 2002-525833, JP 2003-31366, JP 2002-226495, JP 2002-234894, JP 2002-233506 Japanese Patent Laid-Open No. 2002-24175 JP, JP 2001-319779, JP 2001-319780, JP 2002-62824, JP 2002-1000047, JP 2002-203679, 2002-343572. JP, 2002-203678, JP, 2007-284549, JP, 2008-16827, JP, 2008-303150, JP, 2008-311607, JP, 2008-311608, International WO 06/121181, WO 06/46980, WO 07/23659, WO 07/29461, WO 07/95118, International Publication No. 08/140069 and the like.

(Fluorescent dopant (also called fluorescent compound))
Fluorescent dopants include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes , Polythiophene dyes, rare earth complex phosphors, and the like, and compounds having a high fluorescence quantum yield such as laser dyes.

  In the present invention, the light emitting dopant may be used in combination of a plurality of types of compounds, a combination of phosphorescent dopants having different structures, or a combination of a phosphorescent dopant and a fluorescent dopant.

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

(Luminescent host compound (also referred to as luminescent host))
In the present invention, the host compound is a compound contained in the light emitting layer, the mass ratio in that layer is 20% or more, and the phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.). , Defined as compounds 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.

  There is no restriction | limiting in particular as a light emission host which can be used for this invention, The compound conventionally used with an organic EL element can be used. Typical compounds include those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, carboline derivatives and diazacarbazole. Derivatives (herein, diazacarbazole derivatives are those in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom) and the like.

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

  In the present invention, as the luminescent host, the compound represented by the general formula (1) according to the present invention or a known luminescent host may be used alone, or a plurality of types may be used in combination.

  By using a plurality of types of light-emitting hosts, the movement of charges can be adjusted, and the organic EL element can be made highly efficient.

  Moreover, it becomes possible to mix different light emission by using multiple types of well-known compounds used as the said phosphorescence dopant, and, thereby, arbitrary luminescent colors can be obtained.

  In addition, the light emitting host used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable light emitting host). Of course, one or more of such compounds may be used.

  Specific examples of the known light-emitting host 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, 2002-343568, 2002-141173, 2002-35295
No. 7, No. 2002-203683, No. 2002-363227, No. 2002-231453, No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934 Publication No. 2002-260861 Publication No. 2002-280183 Publication No. 2002-299060 Publication No. 2002-302516 Publication No. 2002-305083 Publication No. 2002-305084 Publication No. 2002-308837 Gazette etc.

  Hereinafter, although the specific example of the conventionally well-known compound used as a light emission host of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

  Particularly preferred as the light-emitting host of the light-emitting layer of the organic EL device of the present invention is the above-described compound represented by the general formula (1) according to the present invention. Can be mentioned.

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

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can.

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-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.

  Hereinafter, although the specific example of the compound preferably used for formation of the positive hole transport layer of the organic EL element of this invention is given, this invention is not limited to these.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material having a function of transporting electrons and a very small ability to transport holes. By blocking the holes, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the said electron carrying layer can be used as a hole-blocking layer as needed.

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

  For the hole blocking layer, the carbazole derivatives and azacarbazole derivatives mentioned above as the host compounds (where azacarbazole derivatives are those in which one or more carbon atoms constituting the carbazole ring are replaced by nitrogen atoms) Preferably).

  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 electrons at the HOMO (highest occupied orbital) level of the compound to the vacuum level, and can be determined by, for example, the following method.

(1) Gaussian 98 (Gaussian 03, Revision D02, MJ Frisch, et al, Gaussian, Inc., Wallingford CT, 2004.), which is molecular orbital calculation software manufactured by Gaussian, USA, is used as a keyword, and B3LYP / 6. It can be obtained as a value (eV unit converted value) calculated by performing structural optimization using -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 said positive hole transport layer can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron blocking layer according to the present invention is preferably 3 nm to 100 nm, more preferably 3 nm to 30 nm.

<< Injection layer: electron injection layer (cathode buffer layer), hole injection layer >>
The injection layer is a layer provided as necessary. Specifically, there are an electron injection layer and a hole injection layer. As described above, 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. It may be present between.

  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), 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, alkali metal compound buffer layer typified by lithium fluoride, sodium fluoride and potassium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, and aluminum oxide And an oxide buffer layer. 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.

  In addition, the materials used for the anode buffer layer and the cathode buffer layer can be used in combination with other materials. For example, they can be used in a mixture in a hole transport layer or an electron transport layer. .

"anode"
As an anode applicable to the organic EL device of the present invention, an anode using a metal, an alloy, an electrically conductive compound, and a mixture thereof having a high work function (4 eV or more) is preferable. 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 of 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.

  In addition, when a material that can be applied, such as an organic conductive compound, is used, a wet film forming method such as a printing method or a coating method 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 ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

  The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as 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》
The 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 is not particularly limited in type, such as glass, plastic, etc., and 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.

The surface of the resin film may be formed with an inorganic film, an organic film, or a hybrid film of both, and the water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably a barrier film having a barrier film of 0.01 g / (m ² · 24 h) or less, and moreover, by a method based on JIS K 7126-1987. It is a highly barrier film having a measured oxygen permeability of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 1 × 10 ⁻⁵ g / (m ² · 24 h) or less. Is preferred.

  The material for forming the barrier film may be any material that has a function of preventing the intrusion of factors that affect the deterioration of the organic EL element such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, etc. Can be used. In order to further improve the brittleness of the coating, it is more preferable to have a laminated structure of these inorganic layers and organic 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, or the like can be used, but an atmospheric pressure plasma treatment 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.

  In the organic EL device of the present invention, the external extraction efficiency of light emission at room temperature 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.

<< Method for Manufacturing Organic EL Element >>
As an example of a method for producing an organic EL device, an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode A manufacturing method will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on an appropriately selected substrate so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm, thereby producing an anode.

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, or a cathode buffer layer, which is a component of the device, is formed on the anode. .

  In the organic EL device of the present invention, it is preferable that at least the cathode and the electron transport layer adjacent to the cathode are applied and formed by a wet method.

  Wet methods include spin coating, casting, die coating, blade coating, roll coating, ink jet, printing, spray coating, curtain coating, and LB, but precise thin films can be formed. In view of high productivity, a method having roll-to-roll method suitability such as a die coating method, a roll coating method, an ink jet method, and a spray coating method is preferable. Different film forming methods may be applied for each layer.

  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 dimethylformamide (DMF) and dimethylsulfoxide (DMSO) can be used.

  Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic dispersion method, a high shearing force dispersion method, and a media dispersion method.

  After forming each of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and an organic EL having a desired configuration is provided by providing a cathode. An element is obtained.

  Further, the order can be reversed, and the cathode, cathode buffer layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode can be formed in this order.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 V to 40 V with the 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.

  The organic EL device of the present invention is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is preferable to perform the work in a dry inert gas atmosphere.

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

  As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.

  Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

  In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned.

Furthermore, the polymer film has an oxygen permeability of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less measured by a method according to JIS K 7126-1987, and a method according to JIS K 7129-1992. It is preferable that the water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured in (1) is 1 × 10 ⁻³ g / (m ² · 24 h) or less.

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

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

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.

  Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

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

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

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, 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 for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain a device having higher luminance or durability.

  When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

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

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

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

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

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

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

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

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

  As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<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, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.

  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 a total CS-1000 (Konica Minolta Sensing Co., Ltd.) is applied to the CIE chromaticity coordinates.

Further, when the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

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

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

  In the case of patterning only the light emitting layer, the method is not limited. However, the vapor deposition method, the ink jet method, the spin coating method, and the printing method are preferable.

  The configuration of the organic EL element provided in the display device is selected from the above-described configuration examples of the organic EL element as necessary.

  Moreover, the manufacturing method of an organic EL element is as having shown to the one aspect | mode of manufacture of the organic EL element of said invention.

  In the case of applying a DC voltage to the obtained multicolor display device, light emission can be observed by applying a voltage of about 2V to 40V with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

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

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

  Light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. The present invention is not limited to these examples.

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

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

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

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

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

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

  FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward). The scanning line 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not) When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data. Full-color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region on the same substrate.

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

  FIG. 3 is a schematic diagram illustrating an example of a pixel.

  The pixel 3 includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied to the drain of the switching transistor 11 from the control unit B (not shown) via the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

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

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

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

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

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

  FIG. 4 is a schematic diagram illustrating an example of a passive matrix type full-color display device.

  In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween. When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal. In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

《Lighting device》
Next, an illumination device to which the organic EL element of the present invention is applied will be described.

  The organic EL element of the present invention may be used as an organic EL element having a resonator structure, and the purpose of use of the organic EL element having such a resonator structure is as follows. Examples include, but are not limited to, a light source of a copying machine, a light source of an optical communication processor, and a light source of an optical sensor. Moreover, you may use for the said use by making a laser oscillation.

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

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

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

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

  It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask or the like is not necessary. In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, or the like, and productivity is also improved.

  According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.

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

<< One Embodiment of Lighting Device of the Present Invention >>
One aspect of the lighting device of the present invention including the organic EL element of the present invention will be described.

  The non-light emitting surface of the organic EL device of the present invention is covered with a glass case, a glass substrate having a thickness of 300 μm is used as a sealing substrate, and an epoxy-based photocurable adhesive (LUX TRACK manufactured by Toagosei Co., Ltd.) is used as a sealing material. LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured and sealed, and an illumination device as shown in FIGS. Can be formed.

  FIG. 5 is a schematic view showing an example of a lighting device including the organic EL element of the present invention. In FIG. 5, the organic EL element 101 of the present invention is covered with a glass cover 102. The sealing operation with the glass cover is preferably performed in an atmosphere of a nitrogen atmosphere (a high purity nitrogen gas with a purity of 99.999% or more) without bringing the organic EL element 101 into contact with the atmosphere.

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

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<< Production of organic EL element >>
[Production of Organic EL Element 1-1]
A substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing an ITO (indium tin oxide) film with a thickness of 100 nm on a glass plate of 100 mm × 100 mm × 1.1 mm was used to pattern the ITO film into an electrode pattern to form an anode. After producing an electrode (ITO transparent electrode), the transparent support substrate provided with the ITO transparent electrode 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. On the other hand, 200 mg of copper phthalocyanine (CuPc) is put into a molybdenum resistance heating boat, 200 mg of the hole transport material 1 is put into another molybdenum resistance heating boat, and the exemplified compound Host-9 is used as a host compound in another molybdenum resistance heating boat. 200 mg, 100 mg of Illustrated Compound Ir-12 as a dopant compound in another molybdenum resistance heating boat, 200 mg of the electron transport material 1 in another molybdenum resistance heating boat, and further in another molybdenum resistance heating boat 200 mg of ET-8 (BAlq) was added and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber of the vacuum deposition apparatus to 4 × 10 ⁻⁴ Pa, the heating boat containing CuPc was energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / sec. A hole injection layer was provided.

  Further, the heating boat containing the hole transport material 1 was heated by energization, and was deposited on the hole injection layer at a deposition rate of 0.1 nm / sec to provide a 20 nm hole transport layer.

  Further, the heating boat containing Exemplified Compound Host-9 and Exemplified Compound Ir-12 was energized and heated, and co-deposited on the hole transport layer at a deposition rate of 0.1 nm / sec and 0.006 nm / sec, respectively. Then, a 20 nm light emitting layer was provided.

  Further, the heating boat containing the electron transport material 1 was energized and heated, and deposited on the light emitting layer at a deposition rate of 0.1 nm / sec to provide a first electron transport layer having a thickness of 30 nm.

  Further, the heating boat containing the exemplified compound ET-8 is energized and heated, and is deposited on the first electron transport layer at a deposition rate of 0.1 nm / sec to provide a second electron transport layer having a thickness of 30 nm. It was. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Then, 0.5 nm of lithium fluoride was vapor-deposited as a cathode buffer layer, and also aluminum 110nm was vapor-deposited, the cathode was formed, and the organic EL element 1-1 was produced.

[Production of Organic EL Elements 1-2 to 1-25]
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-25 were produced in the same manner except that the exemplified compound Host-9 as the host compound was changed to each compound shown in Table 1. .

<< Evaluation of organic EL elements >>
(Production of lighting device)
About the produced said organic EL elements 1-1 to 1-25, according to the following method, the luminance change rate and the voltage change rate were measured as a time-dependent stability parameter | index.

  After producing the organic EL elements 1-1 to 1-25, the non-light emitting surface of each organic EL element is covered with a glass cover, and around the glass cover side where the glass cover and the glass substrate constituting the organic EL element are in contact with each other. An epoxy-based photo-curing adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) is used as a sealant, and this is stacked on the cathode side to be in close contact with the transparent support substrate and cured by irradiating UV light from the glass substrate side. Then, the lighting device having the configuration shown in FIGS. 5 and 6 was formed.

(Stability over time)
Next, using the produced lighting device, the temporal stability was evaluated according to the following measurement method.

After each organic EL device was stored at 85 ° C. for 24 hours, each brightness and each voltage were measured when driven under a constant current condition of ^2.5 mA / cm ² at room temperature (about 23 ° C. to 25 ° C.) before and after storage. Then, each luminance ratio and each voltage ratio were determined according to the following formulas, and this was used as a measure of stability over time.

Luminance change rate (%) = luminance after storage ( ^2.5 mA / cm ² ) / luminance before storage ( ^2.5 mA / cm ² ) × 100
Voltage change rate (%) = drive voltage after storage ( ^2.5 mA / cm ² ) / voltage before storage ( ^2.5 mA / cm ² ) × 100
The results obtained as described above are shown in Table 1.

  As is clear from the results shown in Table 1, it is clear that the organic EL device of the present invention is superior in stability over time (luminance change rate, voltage change rate) as compared with the comparative organic EL device.

Example 2
<< Production of organic EL element >>
[Production of Organic EL Element 2-1]
A substrate (NH45 manufactured by NH Techno Glass) having an ITO (indium tin oxide) film formed on a glass plate of 100 mm × 100 mm × 1.1 mm with a thickness of 100 nm was patterned into an electrode pattern to form an anode After producing an electrode (ITO transparent electrode), the transparent support substrate provided with the ITO transparent electrode 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, using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, A thin film was formed by spin coating under conditions of 30 seconds and then dried at 200 ° C. for 1 hour to provide a 20 nm-thick hole transport layer.

  The transparent support substrate provided with the hole transport layer was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 2 dissolved in 10 ml of toluene was placed on the hole transport layer under conditions of 1500 rpm and 30 seconds. A thin film was formed by spin coating on the transport layer. Further, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization and crosslinking, thereby forming a second hole transport layer having a thickness of about 20 nm.

  A thin film was formed on this second hole transport layer by spin coating using a solution of 100 mg of exemplified compound Host-9 and 10 mg of exemplified compound Ir-17 in 10 ml of toluene at 600 rpm for 30 seconds. Formed. It vacuum-dried at 60 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 70 nm.

  Next, a thin film was formed on the light emitting layer by a spin coating method using a solution obtained by dissolving 50 mg of the electron transport compound 2 in 10 ml of hexafluoroisopropanol (HFIP) at 1000 rpm for 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 30 nm.

Subsequently, this substrate was fixed to a substrate holder of a vacuum deposition apparatus, and after the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, lithium fluoride was deposited at 0.4 nm as a cathode buffer layer, and aluminum was deposited at 110 nm as a cathode. Thus, a cathode was formed, and an organic EL element 2-1 was produced.

[Production of Organic EL Elements 2-2 to 2-17]
In the production of the organic EL device 2-1, the organic EL devices 2-2 to 2-17 were produced in the same manner except that the exemplified compound Host-9, which is a host compound, was changed to each compound shown in Table 2. .

<< Evaluation of organic EL elements >>
(Production of lighting device)
About the produced said organic EL elements 2-1 to 2-17, it sealed similarly to the organic EL elements 1-1 to 1-24 described in Example 1, and consists of a structure shown in FIG. 5, FIG. A lighting device was formed.

(Evaluation)
The following evaluation was performed about each illuminating device which has the obtained organic EL elements 2-1 to 2-17.

<Measurement of external extraction quantum efficiency>
Each organic EL element is allowed to emit light at room temperature (about 23 ° C. to 25 ° C.) at a constant current of ^2.5 mA / cm ² , and the light emission luminance (L) [cd / m ² ] immediately after the start of light emission is measured. Thus, the external extraction quantum efficiency (η) was calculated. In addition, CS-1000 (made by Konica Minolta Sensing) was used for the measurement of light emission luminance. The external extraction quantum efficiency was expressed as a relative value with the organic EL element 2-1 being 100. The larger the value, the higher the external extraction quantum efficiency.

<Measurement of drive voltage>
The voltage when each organic EL element was driven under a constant current condition of room temperature (about 23 ° C. to 25 ° C.) and ^2.5 mA / cm ² was measured, and each measurement result was calculated according to the following formula. The relative values with the element 2-1 (comparative example) as 100 are shown.

Relative drive voltage = (drive voltage of each element / drive voltage of organic EL element 2-1) × 100
A smaller value indicates a lower drive voltage.

<Measurement of luminous lifetime>
Each organic EL element was subjected to continuous light emission under a constant current condition of ^2.5 mA / cm ² at room temperature, and the time (τ _1/2 ) required to achieve half the initial luminance was measured. In addition, the light emission lifetime was represented by the relative value which sets the organic EL element 2-1 to 100. The larger the value, the longer the light emission lifetime.

  The obtained results are shown in Table 2.

  As is clear from the results shown in Table 2, it is clear that the organic EL element of the present invention is superior in external extraction quantum efficiency, drive voltage, and emission lifetime as compared with the comparative organic EL element. .

Example 3
<< Production of organic EL element >>
[Production of Organic EL Element 3-1]
A substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing an ITO (indium tin oxide) film with a thickness of 100 nm on a glass plate of 100 mm × 100 mm × 1.1 mm was used to pattern the ITO film into an electrode pattern to form an anode. After producing an electrode (ITO transparent electrode), the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, 200 mg of copper phthalocyanine (CuPc: mentioned above) is put into one molybdenum resistance heating boat, and the hole transport material 3 is put into another molybdenum resistance heating boat. 200 mg of Exemplified Compound Host-9 as a host compound in another molybdenum resistance heating boat, and 100 mg of Exemplified Compound Ir-20 as a dopant compound in another molybdenum resistance heating boat, and another molybdenum resistance heating boat 200 mg of Exemplified Compound ET-8 (BAlq) was placed in a boat and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing CuPc is heated by energization, and deposited on a transparent support substrate at a deposition rate of 0.1 nm / sec. Was provided.

  Further, the heating boat containing the hole transporting material 3 was energized and heated, and deposited on the hole injection layer at a deposition rate of 0.1 nm / sec to provide a 20 nm hole transporting layer.

  Further, the heating boat containing Exemplified Compound Host-9 and Exemplified Compound Ir-20 was energized and heated, and co-deposited on the hole transport layer at vapor deposition rates of 0.1 nm / sec and 0.006 nm / sec, respectively. Then, a 20 nm light emitting layer was provided.

  Furthermore, it supplied with electricity to the said heating boat containing exemplary compound ET-8, it heated, and it vapor-deposited on the said light emitting layer with the vapor deposition rate of 0.1 nm / sec, and provided the electron carrying layer with a film thickness of 30 nm. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Then, 0.5 nm of lithium fluoride was vapor-deposited as a cathode buffer layer, and also aluminum 110nm was vapor-deposited, the cathode was formed, and the organic EL element 3-1 was produced.

[Production of Organic EL Elements 3-2 to 3-13]
In the production of the organic EL element 3-1, the organic EL elements 3-2 to 3-13 were similarly prepared except that the exemplified compound ET-8, which is an electron transport material, was changed to each compound shown in Table 3. Produced.

<< Evaluation of organic EL elements >>
(Production of lighting device)
About the produced said organic EL elements 3-1 to 3-13, it seals similarly to the organic EL elements 1-1 to 1-24 described in Example 1, and consists of a structure shown in FIG. 5, FIG. A lighting device was formed.

(Evaluation)
The following evaluation was performed about each illuminating device which has the obtained organic EL elements 3-1 to 3-13.

<Evaluation of external extraction quantum efficiency and emission lifetime>
The external extraction quantum efficiency and the light emission lifetime were evaluated in the same manner as in the method described in Example 2.

<Measurement of voltage rise rate>
When each organic EL element was driven at a constant current of 6 mA / cm ² , the initial voltage and the voltage after 150 hours were measured. Next, the relative value of the voltage after 100 hours when the initial voltage was 100 was taken as the voltage increase rate. The smaller the voltage increase rate, the better the storage stability.

  Table 3 shows the evaluation results obtained as described above.

  As is clear from the results shown in Table 3, it is clear that the organic EL device of the present invention is superior in external extraction quantum efficiency, emission lifetime, and voltage increase rate compared to the comparative organic EL device. is there.

Example 4
<< Production of organic EL element >>
[Production of Organic EL Element 4-1]
A substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing an ITO (indium tin oxide) film with a thickness of 100 nm on a glass plate of 100 mm × 100 mm × 1.1 mm was used to pattern the ITO film into an electrode pattern to form an anode. After producing an electrode (ITO transparent electrode), the transparent support substrate provided with the ITO transparent electrode 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, using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm After forming a thin film by a spin coat method for 30 seconds, the film was dried at 200 ° C. for 1 hour to provide a 20 nm-thick hole transport layer.

  The transparent support substrate provided with this hole transport layer was transferred to a nitrogen atmosphere, and 3 mg of hole transport material 4 and 47 mg of hole transport material 2 (supra) were added to 10 ml of toluene on the hole transport layer. The dissolved mixed solution was spin-coated on the hole transport layer at 1500 rpm for 30 seconds to form a thin film. In a nitrogen atmosphere, ultraviolet light was irradiated at 120 ° C. for 90 seconds to carry out photopolymerization and crosslinking to form a second hole transport layer having a thickness of about 20 nm.

  On this second hole transport layer, a thin film was formed by spin coating using a solution of 100 mg of exemplified compound Host-9 and 15 mg of exemplified compound Ir-17 in 10 ml of toluene at 1000 rpm for 30 seconds. After forming, it was vacuum dried at 60 ° C. for 1 hour to obtain a light emitting layer.

  Next, a thin film was formed on the light emitting layer by spin coating using a solution of 50 mg of Comparative Compound 7 dissolved in 10 ml of hexafluoroisopropanol (HFIP) at 1000 rpm for 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 30 nm.

Subsequently, this substrate was fixed to a substrate holder of a vacuum deposition apparatus, and after the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, lithium fluoride was deposited at 0.4 nm as a cathode buffer layer, and aluminum was deposited at 110 nm as a cathode. Thus, a cathode was formed, and an organic EL element 4-1 was produced.

<< Production of Organic EL Elements 4-2 to 4-10 >>
In the production of the organic EL element 4-1, organic EL elements 4-2 to 4-10 were produced in the same manner except that the comparative compound 7 was changed to each compound shown in Table 4.

<< Evaluation of organic EL elements >>
(Production of lighting device)
About the produced said organic EL elements 4-1 to 4-10, it sealed similarly to the organic EL elements 1-1 to 1-24 described in Example 1, and consists of a structure shown in FIG. 5, FIG. A lighting device was formed.

(Evaluation)
About each illuminating device which has the obtained organic EL elements 4-1 to 4-10, it carried out similarly to the method of Example 2, evaluated external extraction quantum efficiency, a drive voltage, and the light emission lifetime, and obtained. The results are shown in Table 4.

  As is clear from the results shown in Table 4, it is clear that the organic EL device of the present invention is superior in external extraction quantum efficiency, drive voltage, and emission lifetime as compared with the comparative organic EL device. .

Example 5
<< Production of organic EL full-color display device >>
According to the following procedure, an organic EL full-color display device having the configuration shown in FIG. 7 was produced.

  FIG. 7 is a schematic configuration diagram illustrating an example of an organic EL full-color display device. As shown in FIG. 7, after patterning at a pitch of 100 μm on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) on which a ITO transparent electrode 202 was formed with a thickness of 100 nm on a glass substrate 201 to produce an anode, On this glass substrate, a non-photosensitive polyimide partition wall 203 (width 20 μm, thickness 2.0 μm) was formed by photolithography between ITO transparent electrodes.

  Between the polyimide barrier ribs on the ITO electrode, a hole injection layer composition having the following composition was discharged and injected using an inkjet head (manufactured by Epson; MJ800C), irradiated with ultraviolet light for 200 seconds, and then heated at 60 ° C. for 10 seconds. A hole injection layer 204 having a thickness of 40 nm was formed by a drying process for a minute.

  The following blue light-emitting layer composition, green light-emitting layer composition and red light-emitting layer composition are similarly discharged and injected onto the hole injection layer using an inkjet head and dried at 60 ° C. for 10 minutes. Each light emitting layer (205B, 205G, 205R) was formed.

  Next, the exemplary compound 19 was deposited on the light emitting layer by 20 nm so as to cover the light emitting layer, and further lithium fluoride was 0.6 nm and aluminum 106 was vacuum deposited as a cathode by 130 nm to produce an organic EL device.

  The produced organic EL element showed blue, green, and red light emission by applying a voltage to each electrode, and it was confirmed that it could be used as a full-color display device.

(Hole injection layer composition)
Hole transport material 5 20 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (Blue light emitting layer composition)
Exemplified Compound 20 0.7 parts by mass Exemplified Compound Ir-17 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (green light emitting layer composition)
Illustrative Compound Example 20 0.7 parts by mass Illustrative Compound Ir-1 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (red light emitting layer composition)
Illustrative Compound Example 20 0.7 parts by mass Illustrative Compound Ir-21 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass

Example 6
<< Production of White Organic EL Element 9-1 >>
A substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing an ITO (indium tin oxide) film with a thickness of 100 nm on a glass plate of 100 mm × 100 mm × 1.1 mm was used to pattern the ITO film into an electrode pattern to form an anode. After producing an electrode (ITO transparent electrode), the transparent support substrate provided with the ITO transparent electrode 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. Then, the film was formed by spin coating and then 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 70 mg of the hole transport material 6 dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1500 rpm for 30 seconds. After irradiation with ultraviolet light at 110 ° C. for 100 seconds to perform photopolymerization / crosslinking, vacuum drying was performed at 60 ° C. for 1 hour to form a second hole transport layer.

  Next, 60 mg of Exemplified Compound 42, 3.0 mg of Illustrated Compound Ir-9, and 3.0 mg of Illustrated Compound Ir-15 were dissolved in 6 ml of toluene, and the conditions were 1000 rpm and 30 seconds. A film was formed by spin coating. It vacuum-dried at 60 degreeC for 1 hour, and was set as the light emitting layer.

  Further, using a solution obtained by dissolving 30 mg of Exemplified Compound 54 in 5 ml of hexafluoroisopropanol (HFIP), a film was formed by spin coating at 1500 rpm for 30 seconds, and then vacuum-dried at 60 ° C. for 1 hour to block holes. Layered.

Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, and 200 mg of Alq ₃ was put into a molybdenum resistance heating boat and attached to the vacuum vapor deposition apparatus. After reducing the pressure of the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing Alq ₃ was energized and heated, and deposited on the electron transport layer at a deposition rate of 0.1 nm / second to further form a film. 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.

  Subsequently, 0.5 nm of potassium fluoride and 110 nm of aluminum were deposited to form a cathode, and an organic EL element 9-1 was produced.

  As a result of energizing the organic EL element 9-1, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, even if it replaced with the other compound of illustration, it has confirmed that white light emission was obtained similarly.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water trapping agent 201 Glass substrate 202 ITO transparent electrode 203 Partition wall 204 Hole injection layer 205B, 205G, 205R Light emitting layer

Claims (12)

In an organic electroluminescence device having a configuration in which a plurality of organic compound layers are sandwiched between an anode and a cathode, at least one of the organic compound layers contains a compound represented by the following general formula (1) An organic electroluminescence device characterized by the above.

[Wherein, X represents -O- or -S-. R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ each represents a hydrogen atom or a substituent, and at least one of R ₂ and R ₅ may be substituted, an alkyl group, a cycloalkyl group , Phenyl group, naphthyl group, fluorenyl group, aromatic heterocyclic group, aryloxycarbonyl group, alkylsulfonyl group or cyano group . Y ₁ and Y ₂ each represent a hydrogen atom, a substituent, or a group represented by the following general formula (A), and at least one of Y ₁ and Y ₂ is a group represented by the following general formula (A) It is. ]

[Wherein, L represents a divalent linking group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. n represents 0 or an integer of 1 to 3, and when n is 2 or more, the plurality of L may be the same or different. * Represents a linking site with the general formula (1). Ar represents a group represented by the following general formula (B). ]

[Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , R ₁₉ each represents a hydrogen atom or a substituent. * Represents a linking site with L in the general formula (A). ] _2. The organic electroluminescence device according to claim 1, wherein Y ₁ and Y ₂ in the general formula (1) are both groups represented by the general formula (A).   The organic electroluminescence element according to claim 1, wherein n in the general formula (A) is 0. At least one of the substituents represented by R ₂ and R ₅ in the general formula (1) is a group represented by the following general formula (C). The organic electroluminescent element of the item.

[Wherein, X ₀ represents —C (R ₂₁ ) (R ₂₂ ) —, —N (R ₂₃ ) —, —O— or —S—, and E ₁ to E ₈ each represents —C (R ₂₄ ) = or -N =, and R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each represents a hydrogen atom or a substituent. * Represents a linking site with the general formula (1). ] The organic electroluminescence device according to claim 4, wherein the group represented by the general formula (C) is a group represented by the following general formula (C-1).

[Wherein, X ₀ represents —C (R ₂₁ ) (R ₂₂ ) —, —N (R ₂₃ ) —, —O— or —S—, and E ₁ to E ₈ each represents —C (R ₂₄ R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each represent a hydrogen atom or a substituent. * Represents a linking site with the general formula (1). ]   The organic electroluminescent element according to claim 1, wherein the compound represented by the general formula (1) is contained in a light emitting layer.   The organic electroluminescence device according to claim 6, wherein the light emitting layer contains a phosphorescent compound.   At least 1 layer of the said organic compound layer is an electron carrying layer, The compound represented by the said General formula (1) is contained in this electron carrying layer, The any one of Claim 1 to 7 characterized by the above-mentioned. The organic electroluminescent element of the item.   The layer containing the compound represented by the general formula (1) is formed through a step of forming a film by a wet method (wet process). The organic electroluminescent element of description.   The organic electroluminescent element according to claim 1, which emits white light.   An illuminating device comprising the organic electroluminescent element according to claim 1.   A display device comprising the organic electroluminescence element according to claim 1.

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