JP5593696B2 - Method for manufacturing organic electroluminescence device - Google Patents

Description

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

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements). Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  On the other hand, an organic EL 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. It is an element that emits light by utilizing light emission (fluorescence / phosphorescence) when the exciton is deactivated. Between the electrodes, the thickness is only about 0.1 μm, and the light can be emitted at a relatively low voltage of several volts to several tens of volts. Due to its richness, high visibility, and thin-film type complete solid-state device, it is attracting attention as a next-generation flat display and illumination from the viewpoint of space saving and portability.

  In order to develop an organic EL device that emits light efficiently and with low power consumption, for example, in Japanese Patent No. 3093796, a stilbene derivative, a distyrylarylene derivative, or a tristyrylarylene derivative is doped with a small amount of phosphor. A technique for improving the luminance of light emission and extending the lifetime of the device is disclosed. Japanese Patent Application Laid-Open No. 63-264692 discloses that 8-hydroxyquinoline aluminum complex is used as a host compound and a small amount of phosphor is doped therein. An element having an organic light emitting layer is disclosed, and Japanese Patent Application Laid-Open No. 3-255190 discloses an element having an organic light emitting layer in which an 8-hydroxyquinoline aluminum complex is used as a host compound and doped with a quinacridone dye. It has been.

  However, in the technique disclosed in the above-mentioned patent document, when the emission from the excited singlet is used, the generation ratio of the singlet exciton and the triplet exciton is 1: 3. Since it is 25% and the light extraction efficiency is about 20%, the limit of the external extraction quantum efficiency (ηext) is set to 5%.

  However, M.M. A. Baldo et al. , Nature, 395, 151-154 (1998), since Princeton University reported on an organic EL device using phosphorescence emission from an excited triplet. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), and US Pat. No. 6,097,147, research on materials that exhibit phosphorescence at room temperature has become active.

  In addition, recently discovered organic EL devices that use phosphorescence can realize a luminous efficiency that is approximately four times that of previous devices that use fluorescence. Research and development of light-emitting element layer configurations and electrodes are performed all over the world. For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), a number of compounds have been studied for synthesis centering on heavy metal complexes such as iridium complexes.

  On the other hand, in terms of manufacturing cost and productivity, the structure of the organic EL element is simply a structure in which an organic layer is sandwiched between a transparent electrode and a counter electrode, and compared with a liquid crystal display that is a typical flat display. Since the number of points is overwhelmingly small, the manufacturing cost should be kept low. However, at present, this is not always the case, and the liquid crystal display is largely drained in terms of performance and cost. In particular, in terms of cost, poor productivity is considered as a factor.

Most of organic EL currently commercialized are manufactured by a so-called vapor deposition method in which a low molecular material is vapor deposited to form a film. In this vapor deposition method, a low-molecular compound that can be easily purified can be used as an organic EL material (high-purity material is easy to obtain), and a laminated structure can be easily formed. Although it is excellent, on the other hand, since vapor deposition is performed under a high vacuum condition of 10 ⁻⁴ Pa or less, restrictions are imposed on the film forming apparatus, and in practice it can only be applied to a substrate with a small area, and when multiple layers are laminated In this case, the film formation takes time and the throughput is low. In particular, it becomes a problem when applied to lighting applications and large-area electronic displays, and organic EL elements are one of the causes that are not practically used in such applications.

  On the other hand, the coating method in which the organic compound layer is manufactured by a wet process such as spin coating, ink jet, printing, spraying, etc. can be used to produce a thin film at normal pressure, and is suitable for producing a uniform film over a large area. Yes. However, in order to achieve high luminous efficiency and long life at the same time, it is desirable to stack a plurality of functional layers. In order to laminate a plurality of layers using the coating method, the lower layer is required not to dissolve in the upper layer coating solution, but because it is a very thin film of the order of several tens of nanometers, use a poorly soluble solvent. Even if the upper layer is applied, there arises a problem that the lower layer film dissolves or the interface is disturbed by the solvent. Such contamination to the upper layer of the lower layer material and disturbance of the interface cause a decrease in the light emission efficiency of the element and a deterioration in the element life, and therefore need to be improved.

  In order to solve the above problems, for example, it has been proposed to use a polymer material. However, in general, polymer materials are difficult to purify, and in particular, organic electroluminescence devices are difficult to apply because very few impurities cause the light emission lifetime of the device to be greatly reduced.

  Further, as a method not using a polymer material, there is a technique of forming a constituent layer of an organic EL element using a low molecular material and then increasing the molecular weight thereof. For example, a bifunctional triphenylamine derivative having two vinyl groups in the molecule is disclosed, and after forming a film using the compound, a three-dimensionally crosslinked polymer can be formed by ultraviolet irradiation ( For example, see Patent Document 1.) A technique for adding a material having two or more vinyl groups to a plurality of layers is disclosed, and a polymerization reaction is also performed by irradiation with ultraviolet rays or heat at the time of forming an organic layer before laminating a cathode (for example, patents) Reference 2)), AIBN (azoisobutyronitrile), which is a radical generator, is added to a mixture of a material having a vinyl group at the end of a phosphorescent dopant and a comonomer having a vinyl group, and polymerized during film formation. Production methods for causing the reaction to proceed (for example, see Patent Document 3), production methods for causing a Diels-Alder reaction between two molecules in the same layer (for example, see Patent Document 4), and the like. .

However, as described above, ultraviolet irradiation and heat treatment at a high temperature to increase the molecular weight (resinization) of low molecular weight materials cause generation of oxides and deterioration of materials. There was a problem of adversely affecting the service life.
Japanese Patent Laid-Open No. 5-271166 JP 2001-297882 A Japanese Patent Laid-Open No. 2003-73666 JP 2003-86371 A

  The present invention has been made in view of such problems, and an object of the present invention is to provide an organic EL element material that exhibits high luminous efficiency and has a long lifetime, and an organic EL element, an illumination device, and a display device that use the material. It is to provide.

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

1. Emitting layer, a method of manufacturing an organic electroluminescent device that have a electron-transporting layer,
Has a partial structure represented by the following general formula (1), and under normal pressure, compound solubility is less than 0.05 g / L for put that i so- butanol 25 ° C., and the following general formula (2) Forming the light emitting layer containing the metal complex compound represented ,
Forming the electron transport layer on the light emitting layer by a wet method;
The manufacturing method of the organic electroluminescent element characterized by having .

(In the general formula (1), Ar represents a divalent arylene group, Ya represents any of O, S, and N-Ra, Yb represents any of O, S, and N-Rb, and Ya and Yb may be different or the same, Ra and Rb each represent a substituent or a bond, and RA and RB each represent an aromatic hydrocarbon ring group, an aromatic heterocyclic group, an alkyl group, an alkenyl group, or an acyloxy group , when RA and RB have multiple, they are _.Xa 1 _{~Xa 8} and _Xb 1 _{~Xb 8} may be the same or different from each other represent C-Ra ₁ or a nitrogen atom, Ra ₁ is hydrogen atom, a substituent or Represents a bond. When there are a plurality of C-Ra ₁ , Ra ₁ may be different or the same.)

(In General Formula (2), X ₄ represents a carbon atom or a nitrogen atom, and has an aromatic hydrocarbon ring group having a substituent or an aromatic heterocyclic group having a substituent. Y is a carbon atom or nitrogen. Represents an atom, A represents a 6-membered aromatic hydrocarbon ring or aromatic heterocycle, B represents a 5-membered or 6-membered aromatic heterocycle, and X ₁ -L ₁ -X ₂ represents a bidentate arrangement. X ₁ and X ₂ each independently represents a carbon atom, a nitrogen atom or an oxygen atom, L ₁ represents an atomic group which forms a bidentate ligand together with X ₁ and X ₂ , m1 1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, but m1 + m2 is 2 or 3. M as a central metal represents a group 8-10 metal in the periodic table. )
2. 2. The method for producing an organic electroluminescent element according to 1 above, wherein the general formula (2) is represented by the following general formula (3).

(In the general formula (3), Z is an aromatic hydrocarbon ring group or table to an aromatic heterocyclic group having a substituent. A is a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring having a substituent X ₁ -L ₁ -X ₂ represents a bidentate ligand, X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom, and L ₁ represents ₂ together with X ₁ and X 2. Represents an atomic group forming a ligand of a locus, m1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, and m1 + m2 is 2 or 3. A central metal. M represents a metal of group 8 to 10 in the periodic table.)
3. 3. The method for producing an organic electroluminescent element according to 2, wherein A in the general formula (3) represents a benzene ring.

4). 4. The method for producing an organic electroluminescent element according to 2 or 3 , wherein the metal complex compound represented by the general formula (3) is composed of only the same ligand.

5. M of the said General formula (3) is iridium or platinum, The manufacturing method of the organic electroluminescent element of any one of said 2-4 characterized by the above-mentioned.

6). 6. The method for producing an organic electroluminescent element according to any one of 1 to 5, wherein the compound having a partial structure represented by the general formula (1) has a molecular weight of 700 to 3000.

7). Ar in said General formula (1) is represented by following General formula (4), The manufacturing method of the organic electroluminescent element of any one of said 1-6 characterized by the above-mentioned.

(In the general formula (4), Yc represents O, S, one of the N-Rc, Rc is _.Xc 1 Xc ₈ representing a substituent represents a carbon atom or a nitrogen atom, the same even if different from each other When any of Xc _{1 to} Xc ₈ is a carbon atom, Rc ₁ to Rc ₈ bonded to the carbon atom represents a hydrogen atom or a substituent, and any of Xc _{1 to} Xc ₈ is nitrogen. In the case of an atom, Rc ₁ to Rc ₈ bonded to the nitrogen atom each represent an unshared electron pair, and at least two of Rc and Rc _{1 to} Rc ₈ are used for connection.)
8). 8. The method for producing an organic electroluminescence element as described in 7 above, wherein Xc _{1 to} Xc ₈ in the general formula (4) are all carbon atoms.

9. Yc is O or N-Rc, The manufacturing method of the organic electroluminescent element of said 7 or 8 characterized by the above-mentioned.

10. Yc is N-Rc, The manufacturing method of the organic electroluminescent element of said 9 characterized by the above-mentioned.

11. 11. The method for producing an organic electroluminescence element according to any one of 7 to 10, wherein Rc ₃ and Rc ₆ in the general formula (4) are used for connection.

12 Ar in said General formula (1) is represented by following General formula (5), The manufacturing method of the organic electroluminescent element of any one of said 1-6 characterized by the above-mentioned.

(In General Formula (5), Xd _{1 to} Xd ₆ represent a carbon atom or a nitrogen atom, and may be different or the same. When any of Xd _{1 to} Xd ₆ is a carbon atom, Rd ₁ to Rd ₆ bonded to each other represent a hydrogen atom or a substituent, and when any of Xd _{1 to} Xd ₆ is a nitrogen atom, Rd ₁ to Rd ₆ bonded to the nitrogen atom are each not shared. Represents an electron pair, and at least two of Rd _{1 to} Rd ₆ are used for connection.)
13. 13. The method for producing an organic electroluminescent element as described in 12 above, wherein Xd _{1 to} Xd ₆ in the general formula (5) are all carbon atoms.

14 14. The method for producing an organic electroluminescent element as described in 12 or 13, wherein Rd ₁ and Rd ₃ in the general formula (5) are used for connection.

15. Ya in said General formula (1) represents N-Ra, The manufacturing method of the organic electroluminescent element of any one of said 1-14 characterized by the above-mentioned.

16. 16. The method for producing an organic electroluminescent element as described in 15 above, wherein Ra in the general formula (1) is used for connection with Ar.
17. The method for producing an organic electroluminescent element according to any one of 1 to 16, wherein in the step of forming the electron transport layer, a solution in which an electron transport material is dissolved in a solvent containing alcohols is applied. .

18 . Wherein in the step of forming the electron-transporting layer, a method of manufacturing an organic electroluminescent device according to any one of the 1 to 16, characterized by applying a solution of an electron-transporting material in n- butanol.

19 . Wherein in the step of forming the electron-transporting layer, a method of manufacturing an organic electroluminescent device according to any one of the 1 to 16, characterized by applying a solution of an electron-transporting material in iso- butanol.

20 . Wherein in the step of forming the light emitting layer, a method of manufacturing an organic electroluminescent device according to any one of the 1 to 19, characterized in that to form the light-emitting layer by a wet method.

  According to the present invention, it is possible to provide an organic EL element that exhibits high light emission efficiency and has a long light emission lifetime, an illumination device using the organic EL element, and a display device.

The schematic block diagram of an organic electroluminescent full color display apparatus is shown. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Glass substrate 102 ITO transparent electrode 103 Partition 104 Hole injection layer 105B, 105G, 105R Light emitting layer 207 Glass substrate with a transparent electrode 206 Organic EL layer 205 Cathode 202 Glass cover 208 Nitrogen gas 209 Water capturing agent

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

  First, the compound which has a partial structure represented by General formula (1) in this invention is demonstrated.

  As one of means for laminating the organic compound layer by a wet method, there is a method of using a difference in solubility (Sp value difference) with respect to a solvent used for the upper layer and the lower layer. For example, the upper layer can be formed with a highly polar solvent by using, as the lower layer, a material having a high solubility in a low polarity solvent such as toluene and a low solubility in a highly polar solvent such as methanol.

  However, methanol and ethanol, which are representative of highly polar solvents, have a low boiling point, and thus there is a problem that it is difficult to control the drying conditions at the time of film formation and the film thickness tends to vary. In addition, since a solvent having a very high polarity is likely to contain moisture, water remains in the thin film, which causes a deterioration in device life.

  On the other hand, with hexanol or the like having a large number of carbon atoms, the difference in the Sp value with the lower layer material approaches, which causes a problem that the lower layer material is easily dissolved. At the same time, since the boiling point is increased, the film formability is improved, but it is difficult to completely remove the solvent.

  In view of the above problems, the solvent used for the upper layer is preferably a solvent having good film formability and appropriate polarity, and 1-butanol is a suitable solvent that satisfies the requirements.

  The compound having a partial structure represented by the general formula (1) in the present invention has a solubility in iso-butanol of 0.05 g / L or less at 25 degrees under normal pressure. In the present invention, the method for measuring the solubility of the compound having the partial structure represented by the general formula (1) with respect to iso-butanol may be a very general method. 5 mg of a compound having a partial structure represented by the general formula (1) is added to 100 ml of iso-butanol and stirred for 3 hours. Here, whether or not the compound having the partial structure represented by the general formula (1) is completely dissolved can be visually confirmed and judged. The iso-butanol used here can be sufficiently used as long as it has a purity of JIS reagent first grade or higher.

  The partial structure represented by the general formula (1) according to the present invention will be described below.

In general formula (1), Ar represents a divalent arylene group, and the divalent arylene group is preferably a 1,3-phenylene group, a 1,2-phenylene group, a 3,6-carbazolylene group, 3, It represents an 8-dibenzofuryl group. Ya represents one of O, S, and N-Ra, Yb represents one of O, S, and N-Rb, and Ya and Yb may be different or the same. Ra and Rb represent a substituent. RA and RB represent substituents, and when there are a plurality of RA and RB, they may be different or the same. Xa _{1 to} Xa ₈ and Xb _{1 to} Xb ₈ represent C-Ra ₁ or a nitrogen atom, and Ra ₁ represents a hydrogen atom, a substituent, or a bond. When there are a plurality of C-Ra _{1 s} , Ra _{1 s} may be different or the same.

Examples of the substituent represented by Ra and Rb, RA and RB, and Ra ₁ include, for example, an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group, and a hexyl group). Octyl group, dodecyl 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.), aromatic hydrocarbon ring group (also called aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl Group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group , Pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2, 4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group , Benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) Quinoxalinyl group, pyridazi Group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyl) Oxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (For example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (for example, Phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxy) Carbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecyl) Aminosulfonyl 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, acetyl) Oxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, Propylcarbonylamino group, pentylcarbonylamino group, 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, cyclohexyl). Aminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido) Group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group naphthylureido group, 2-pyridylamido Ureido 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, Lopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (for example, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (For example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, trimethyl group) Phenylsilyl group, phenyldiethylsilyl group, etc.). 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.

  The molecular weight of the compound having the partial structure represented by the general formula (1) is preferably 700 to 3000, since it is easy to purify and a material having a high Tg is obtained.

  In the general formula (1), Ar is preferably represented by the general formula (4).

In the said General formula (4), Yc represents either O, S, and N-Rc, and Rc represents a substituent. Xc _{1 to} Xc ₈ represent a carbon atom or a nitrogen atom, and may be different or the same. When any of Xc _{1 to} Xc ₈ is a carbon atom, Rc ₁ to Rc ₈ bonded to the carbon atom represent a hydrogen atom or a substituent. When any of Xc _{1 to} Xc ₈ is a nitrogen atom, Rc ₁ to Rc ₈ bonded to the nitrogen atom each represent an unshared electron pair. Further, at least two of Rc and Rc _{1 to} Rc ₈ are used for connection.

As the substituent here represented by Rc and _Rc 1 to Rc _8, wherein Ra and Rb, also the same as the substituents represented by RA and RB.

Further, when the Ar in the general formula (1) is represented by the general formula (4), in the general formula _(4), it is preferable Xc 1 Xc ₈ are all carbon atoms. Furthermore, in General formula (4), it is preferable that Yc is O or N-Rc. Yc is more preferably N-Rc.

Further, in the above general formula (4), it is preferable that Rc ₃ and Rc ₆ is used to join. The phrase “Rc ₃ and Rc ₆ are used for linking” means that the general formula (4) constitutes a divalent group with the substitution position of Rc ₃ and Rc ₆ as a bond.

  Ar in the general formula (1) is preferably represented by the general formula (5).

In the general formula (5), Xd _{1 to} Xd ₆ represent a carbon atom or a nitrogen atom, and may be different or the same. When any of Xd _{1 to} Xd ₆ is a carbon atom, Rd ₁ to Rd ₆ bonded to the carbon atom represent a hydrogen atom or a substituent. When any of Xd _{1 to} Xd ₆ is a nitrogen atom, Rd ₁ to Rd ₆ bonded to the nitrogen atom each represent an unshared electron pair. In addition, at least two of Rd _{1 to} Rd ₆ are used for connection. Here, the substituents represented by Rd _{1 to} Rd ₆ are synonymous with the substituents represented by Ra and Rb, and RA and RB.

In the general formula _(5), it is one preferred form Xd 1 ~Xd ₆ are all carbon atoms.

In addition, when Ar in the general formula (1) is represented by the general formula (5), it is preferable that Rd ₁ and Rd ₃ are used for connection in the general formula (5). The phrase “Rd ₁ and Rd ₃ are used for linking” means that the general formula (5) constitutes a divalent group with the substitution position of Rd ₁ and Rd ₃ as a bond.

  On the other hand, Ya in the general formula (1) preferably represents N-Ra, and Ra is preferably used for connection with Ar. That is, it is preferably bonded to Ar at the substitution position of Ra.

  Specific examples of typical compounds are given below.

  Moreover, although an example of the synthesis | combination of the compound represented by General formula (1) based on this invention below is shown, this invention is not limited to these.

  (Synthesis example)

  Add 1 ml of carbazole, 25.0 g of 3-bromoiodobenzene, 13.4 g of potassium carbonate, and 6.2 g of copper (powder) to 90 ml of N, N-dimethylacetamide (dehydrated), and heat to reflux for 7 hours under a nitrogen stream. went. The reaction mixture was cooled to room temperature, insolubles were filtered, water was added, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The resulting mixture was purified by silica gel column chromatography to obtain 17 g of Intermediate 1. The yield was 57%. The structure of the obtained intermediate 1 was confirmed by a nuclear magnetic resonance spectrum and a mass spectrum.

20 g of intermediate 1, 18.9 g of bis (pinacolato) diboron, 12.2 g of potassium acetate, PdCl ₂ (dppf) · CH ₂ Cl ₂ ([1,1′-bis (diphenylphosphino) ferrocene] palladium (II) To 1.0 g of dichloride dichloromethane complex), 300 ml of dimethyl sulfoxide was added and stirred with heating at 100 ° C. for 16 hours under a nitrogen stream. The reaction mixture was cooled to room temperature, insolubles were filtered, water was added, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The resulting mixture was purified by silica gel column chromatography to obtain 20.6 g of intermediate 2. The yield was 90%. The structure of the obtained intermediate 2 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

Intermediate 2 24.6 g, Intermediate 3 13.7 g, potassium carbonate 23.1 g, Pd (dba) ₂ (bis (dibenzylideneacetone) palladium) 0.64 g, dppf (diphenylphosphinoferrocene) 0 To .62 g, 550 ml of 1,2-dimethoxyethane and 70 ml of water were added and heated under reflux for 5 hours. The reaction mixture was cooled to room temperature, insolubles were filtered, water was added, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The resulting mixture was purified by silica gel column chromatography to obtain 16.5 g of intermediate 2. The yield was 72%. The structure of the obtained intermediate 4 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

  To 0.29 g of palladium acetate, 2.1 g of a 50 g / L toluene solution of tert-butylphosphine and 10 ml of xylene (dehydrated) were added and stirred at room temperature for 1 hour under a nitrogen stream. Subsequently, 7.5 g of intermediate 4, 2.9 g of 1,3-diiodobenzene, 2.1 g of sodium t-butoxide, and 120 ml of xylene (dehydrated) were added, and the mixture was heated to reflux for 5 hours under a nitrogen stream. . After cooling the reaction solution to room temperature, insolubles were filtered, water was added, and the mixture was extracted with toluene. The organic layer was repeatedly washed with water and concentrated under reduced pressure. The obtained mixture was purified by silica gel column chromatography, and further recrystallized from toluene to obtain 5.7 g of Exemplified Compound 1-1. The yield was 73%. The obtained exemplary compound 1-1 was confirmed in structure by nuclear magnetic resonance spectrum and mass spectrum.

  In the present invention, the compound having a partial structure represented by the general formula (1) will be described later, but it is preferably contained in the light emitting layer as a host compound.

  Next, the metal complex represented by the general formula (2) in the present invention will be described.

(Ligand)
In the metal complex represented by the general formula (2) according to the present invention, when m1> m2, the partial structure shown in parentheses having m1 or the partial structure represented by a tautomer thereof is the main coordination. A partial structure shown in parentheses having m2 or a partial structure represented by a tautomer thereof is called a subligand.

  In the present invention, the metal complex is composed of a combination of a main ligand or a tautomer thereof and a subligand or a tautomer thereof, which will be described later. All of the ligands of the metal complex may be composed of only the partial structure represented by the main ligand or a tautomer thereof.

  Furthermore, as a so-called ligand used for forming a conventionally known metal complex, the trader may have a known ligand (also referred to as a coordination compound) as a ligand, if necessary.

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

There are various known ligands used in conventionally known metal complexes. For example, “Photochemistry and Photophysics of Coordination Compounds” Springer-Verlag H. Published by Yersin in 1987, “Organometallic Chemistry – Fundamentals and Applications”, published by Akio Yamamoto, Shokabosha Publishing Co., Ltd., published in 1982, etc. (including halogen ligands (preferably chlorine ligands)), including Nitrogen heterocyclic ligands (for example, bipyridyl, phenanthroline, etc.), diketone ligands and the like can be mentioned.

(Transition metal element of group 8-10 of the periodic table)
As a metal used for forming the metal complex represented by the general formula (2) according to the present invention, a transition metal element of group 8 to 10 of the periodic table (also simply referred to as a transition metal) is used. Iridium and platinum are preferable transition metal elements. More preferably, iridium is good.

In the general formula (2), X ₄ represents a nitrogen atom or a carbon atom, and Y represents a carbon atom or a nitrogen atom. A represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring.

  Specific examples of the 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring include benzene ring, chlorobenzene ring, mesitylene ring, toluene ring, xylene ring, naphthalene ring, anthracene ring, azulene ring, acenaphthene ring, fluorene ring, Phenanthrene ring, indene ring, pyrene ring, biphenyl ring, pyridine ring, pyrimidine ring, benzimidazole ring, pyrazine ring, quinoline ring, benzofuran ring, dibenzofuran ring, benzothiophene ring, dibenzothiophene ring, indole ring, carbazole ring, carboline ring , A diazacarbazole ring (in which one of the carbon atoms constituting the carboline ring of the carboline ring is replaced by a nitrogen atom), a quinoxaline ring, a pyridazine ring, a triazole ring, a quinazoline ring, a phthalazine ring, and the like. Is the benzene ring And the like. These groups may be unsubstituted or further have a substituent.

  Furthermore, these aromatic hydrocarbon rings or aromatic heterocycles may be substituted with, for example, a substituent described later, and may further form a condensed ring.

  In the general formula (2), B represents an atomic group necessary for forming a 5- to 6-membered nitrogen-containing aromatic heterocycle, and the 5- to 6-membered nitrogen-containing aromatic heterocycle includes a pyridine ring, Pyrimidine ring, pyrroline ring, imidazole ring, benzimidazole ring, pyrazole ring, pyrazine ring, triazole ring (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.) Oxazole ring, benzoxazole ring, thiazole ring, isoxazole ring, isothiazole ring, furazane ring, isoquinoline ring and the like. Preferably, an imidazole ring is mentioned. These rings may be unsubstituted or may further have a substituent.

  Examples of the substituent include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), A cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), an alkenyl group (eg, vinyl group, allyl group, etc.), an alkynyl group (eg, ethynyl group, propargyl group, etc.), an aromatic hydrocarbon ring group (aromatic carbon) Also referred to as ring group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl Group, biphenylyl group, etc.), aromatic heterocyclic group (for example, 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-triazole-1- Oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, Carbazolyl group, carbolinyl group, diazacarbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl Group), heterocycle (Eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), Cycloalkoxy groups (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy groups (eg, phenoxy group, naphthyloxy group, etc.), alkylthio groups (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group) , Octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, Methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, Aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl groups (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, Rohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy) Group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexyl group) Carbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, Tilcarbonylamino group, etc.), carbamoyl groups (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylamino) Carbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group) , Dodecylureido group, phenylureido group naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethyl) Rusulfinyl 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) 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 Groups (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, Nilino 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, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.).

X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand together with X ₁ and X ₂ . Specific examples of ligands of bidentate represented by X ₁ -L ₁ -X _2, a substituted or unsubstituted phenyl pyridine, phenylpyrazole, phenylimidazole, phenyl triazole, phenyl tetrazole, pyrazabole, acetylacetone, picolinic acid Etc.

  m1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, and m1 + m2 is 2 or 3. Especially, the case where m2 is 0 is preferable.

  The general formula (2) is preferably represented by the general formula (3). In the general formula (3), Z represents a hydrocarbon group, a hydrocarbon ring group or a heterocyclic group, and these have a substituent. Also good.

  Examples of the hydrocarbon group include a methyl group, an ethyl group, and an iso-propyl group. Examples of the hydrocarbon ring group include a non-aromatic hydrocarbon ring group and an aromatic hydrocarbon ring group. Examples of the non-aromatic hydrocarbon ring group include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. These groups may be unsubstituted or have a substituent described later. Examples of the aromatic hydrocarbon ring group (also referred to as aromatic hydrocarbon group, aryl group, etc.) include, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl. Group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like.

  Examples of the heterocyclic group include a non-aromatic heterocyclic group and an aromatic heterocyclic group. Examples of the non-aromatic heterocyclic ring in the non-aromatic heterocyclic group include an epoxy ring, an aziridine ring, a thiirane ring, and an oxetane ring. , Azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexa Hydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1, 1-dioxide ring, pyranose Rings, diazabicyclo [2,2,2] octane rings and the like can be raised, and groups derived therefrom can be exemplified.

  Examples of the aromatic heterocyclic group include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl). Group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group , Benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl Group, pyridazinyl group, triazinyl group, key Zoriniru group, phthalazinyl group, and the like. These groups may be unsubstituted or may further have a substituent. Examples of these substituents include those having the same meaning as the substituents in the aromatic hydrocarbon ring or aromatic heterocyclic ring.

  In the general formula (3), A represents a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring as in the general formula (2), and among these, A preferably represents a benzene ring. .

  Moreover, in General formula (3), it is preferable that a metal complex compound is comprised only with the same ligand.

  m1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, and m1 + m2 is 2 or 3. M, which is a central metal, represents a group 8-10 metal in the periodic table.

(Transition metal element of group 8-10 of the periodic table)
M in the general formula (3) according to the present invention represents a group 8-10 transition metal element (also simply referred to as a transition metal) in the periodic table, and among them, iridium and platinum are preferable transition metal elements. . More preferably, iridium is good.

  Hereinafter, although the preferable example of Z in General formula (3) is given, Z is not limited to these examples, and may have a substituent other than the following illustrations. Note that * represents a bonding position.

  Hereinafter, although the specific example of the metal complex represented by the said General formula (2) based on this invention is shown, this invention is not limited to these.

  These metal complexes are described in, for example, Organic Letter, vol. 16, 2579-2581 (2001), Inorganic Chemistry, Vol. 30, No. 8, 1685-1687 (1991), J. Am. Am. Chem. Soc. , 123, 4304 (2001), Inorganic Chemistry, Vol. 40, No. 7, 1704-1711 (2001), Inorganic Chemistry, Vol. 41, No. 12, 3055-3066 (2002) New Journal of Chemistry, Vol. 26, page 1171 (2002), European Journal of Organic Chemistry, Vol. 4, pages 695-709 (2004), and methods such as references described in these documents. It can be synthesized by applying.

  The present invention is suitable for forming a thin film with a uniform film over a large area when the organic compound layer in the organic EL element is laminated by a wet process such as coating, ink jetting, printing, and spraying. In general, in order to stack multiple layers using the coating method, the lower layer must be insoluble in the upper layer coating solution. However, since it is a thin film on the order of several tens of nanometers, a poorly soluble solvent is used. Even if the upper layer is applied, the lower layer film dissolves or the interface is disturbed by the solvent, but in the present invention, the compound having the partial structure represented by the general formula (1), Since the compound has a solubility in iso-butanol of 0.05 g / L or less at 25 ° C. under normal pressure, a light emitting layer containing the compound and the metal complex compound represented by the general formula (2) is prepared. About forming an electron transport layer adjacent to the light emitting layer after forming a light emitting layer, it is preferable to apply and form the electron transport layer using n-butanol or iso-butanol as a coating solvent.When the electron transport layer is formed on the light emitting layer having the above-described solubility profile by a wet method, the contamination of the upper layer of the lower layer material and the disturbance of the interface do not occur, and when the organic EL element is formed, the luminous efficiency is improved. It does not cause a drop or deterioration of the device life.

  As the wet method, in addition to the above-described application (spin coating, bar coating, die coating, spray coating, etc., any method may be used), an ink jet method, for example, a method such as screen printing is included.

  Further, a compound having a partial structure represented by the general formula (1) and having a solubility in iso-butanol of 25 g or less at 25 ° C. under normal pressure, and the general formula (2) From the viewpoint of productivity, the light emitting layer itself containing the metal complex compound represented by) is formed by a wet method, and an electron transport layer is further formed by a wet method on the light emitting layer formed by the wet method. It is preferable.

  The compound having the partial structure represented by the general formula (1) according to the present invention can be used in any of the constituent layers of the organic EL device of the present invention described later, but the external extraction quantum efficiency is improved. From the viewpoint of extending the light emission lifetime, it is preferably contained in the light emitting layer.

  Moreover, as a light emission dopant which concerns on this invention, the metal complex represented by the said General formula (2) or (3) is preferable.

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

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode In the organic EL device of the present invention, the blue light emitting layer preferably has a light emission maximum wavelength of 430 nm to 480 nm, and the green light emitting layer has a light emission maximum wavelength of 510 nm to 550 nm, The red light emitting layer is preferably a monochromatic light emitting layer having a light emission maximum wavelength in the range of 600 nm to 640 nm, and is preferably a display device using these. Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

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

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The total film thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing unnecessary application of high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust in the range of 2 nm to 5 μm, more preferably in the range of 2 nm to 200 nm, and particularly preferably in the range of 10 nm to 80 nm.

  For the production of the light emitting layer, a light emitting dopant and a host compound described later are applied, for example, a spin coating method, a die coating method, etc., a coating method, a wet method such as an ink jet method, a screen printing method, a casting method, an LB method, a vacuum. The film can be formed by a known thinning method such as a vapor deposition method. When using the compound of this invention for a light emitting layer, forming by a wet method is preferable.

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

(Host compound (also called luminescent host))
The host compound used in the present invention will be described.

  Here, the host compound in the present invention is a phosphorescent quantum yield of phosphorescence emission at a room temperature (25 ° C.) having a mass ratio of 20% or more in the compound contained in the light emitting layer. Is defined as a compound of less than 0.1. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer. Moreover, when it has a several light emitting layer, it is preferable that mass ratio 20% or more of the host compound of each of these layers is the same compound, since it is easy to obtain a uniform film property over the whole organic layer.

  The host compound used in the present invention has a partial structure represented by the general formula (1), and the solubility of the compound in iso-butanol at 25 ° C. under normal pressure is 0.05 g / L or less. Containing compounds. In the present invention, a known host compound may be used in combination.

  As a host compound, you may use individually or may be used in combination of multiple types. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient.

  The host compound used in the present invention preferably has a Tg of 100 ° C. or higher. When Tg is lower than 100 ° C., the deterioration of the element with time (decreased doorway, deterioration in film properties) is large, and also in the production process, there are many restrictions in terms of the drying process and the like, which is not preferable. That is, in order to satisfy brightness, durability, and productivity, Tg is preferably 100 ° C. or higher. Tg is more preferably 130 ° C. or higher.

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

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

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

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

  As the light-emitting dopant according to the present invention, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used. From the viewpoint of obtaining an organic EL device having higher luminous efficiency, the above-mentioned host compound may be used as the luminescent dopant (simply referred to as a luminescent material) used in the light emitting layer or the light emitting unit of the organic EL device of the present invention. It is preferable to contain a phosphorescent dopant at the same time as containing.

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

  The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, it is 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 emitting dopant according to the present invention achieves the above phosphorescence quantum yield (0.01 or more) in any solvent. It only has to be done.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound. The energy transfer type is to obtain light emission from the phosphorescent dopant by transferring to the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, and carrier recombination occurs on the phosphorescent dopant to cause phosphorescence. There is a carrier trap type in which light emission from a photoluminescent dopant can be obtained.

  In any of the above cases, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

  As a phosphorescence-emitting dopant, it can also select from the well-known thing used for the light emitting layer of an organic EL element suitably, and can also use it.

  As the phosphorescent dopant according to the present invention, a metal complex represented by the general formula (2) is used.

  The compound used as the phosphorescent dopant according to the present invention is, for example, Inorg. Chem. 40, 1704 to 1711, and the like.

  In the present invention, the phosphorescent maximum wavelength of the phosphorescent dopant is not particularly limited, and in principle can be obtained by selecting a central metal, a ligand, a ligand substituent, and the like. The emitted light wavelength can be changed.

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

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

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

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

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

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

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

  The hole blocking layer preferably contains the azacarbazole derivative mentioned as the host compound.

  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, the ionization potential of 50 g / L or more of the compound contained in the hole blocking layer provided at the position is preferably 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

  The ionization potential is defined by the energy required to emit an electron at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.

  (1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit converted value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.

  (2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

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

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

  The hole transport material has any 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 as a thin film from 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 inkjet method, or an LB method. However, for example, in the case of laminating and forming a positive hole transport layer and a light emitting layer from the anode, the positive hole transport layer is also a wet method, coating, spin coating method, casting method, printing method including ink jet method, It is preferable that the light emitting layer formed by the LB method or the like and containing the compound of the present invention is similarly formed by the wet method.

  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. This hole transport layer may have a single layer structure composed of one or more of the above materials.

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

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

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. Any material may be used as long as it has a function of transferring electrons to the light-emitting layer, and any material can be selected from conventionally known compounds.

  Examples of compounds used in the electron transport layer include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like. Can be mentioned.

  Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

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

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

  For example, when the positive hole transport layer and the light emitting layer are laminated from the anode, the electron transport layer is formed by using the above electron transport material as a wet method, such as a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. For example, it can be laminated and formed on the light emitting layer containing the compound of the present invention by a wet method.

  The electron transport layer is preferably formed by the above wet method using n-butanol or iso-butanol as a coating solvent.

  Of course, one of the adjacent layers of the light emitting layer may be formed by a method other than the wet method, for example, a method such as vapor deposition.

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

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

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

《Reactive organic compound》
In the present invention, an organic compound having a reactive group (reactive organic compound) may be used in each functional layer. There is no restriction | limiting in particular as a layer using a reactive organic compound, It can use for each layer. An organic material having a function having a reactive group in each functional layer may be used.

  A reactive organic compound can be reacted on a substrate to form a network polymer of organic molecules. Generation | occurrence | production of a network polymer can suppress element deterioration by Tg (glass transition point) adjustment of a structure layer.

  It is also possible to change the emission wavelength of the organic EL element, suppress deterioration of the specific wavelength, etc. by adjusting the reaction accompanied by the cleavage or generation of the conjugated system of the molecule using the active radical in use. is there.

  On the other hand, on the manufacturing side, for example, in the case of a step of laminating by a wet process, it is preferable that the lower layer does not dissolve in the upper layer coating solution, so that the upper layer can be applied by resinizing the lower layer and degrading solvent solubility. can do. For example, when the hole transport layer is resinized as an organic layer thus crosslinked, dissolution and penetration of the lower layer can be prevented when the light emitting layer is applied as the upper layer.

  Although it does not specifically limit as a reactive group which can be used, For example, a vinyl group, an ethynyl group, an isocyanate group, an epoxy group etc. are mentioned typically.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used.

Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.

Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al2O3) mixture. , 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 the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

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

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

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

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

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

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

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

  The external extraction efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more.

  Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

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

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

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

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

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

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

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

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

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

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

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, 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 an element having higher luminance or durability.

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

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

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

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of these, light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode). 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 one of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

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

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

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

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

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

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

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.

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

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

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

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

  After these layers are formed, a thin film made of a cathode material is formed thereon by 1 μm or less, preferably by a method such as vapor deposition or sputtering so that the film thickness is in the range of 50 nm to 200 nm. By providing, a desired organic EL element can be obtained.

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

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Although the light source of a sensor etc. are mentioned, It is not limited to this, 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 device of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like at the time of film formation, if necessary. 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 device may be patterned. Can do.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

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

Example 1
<Measurement of solubility>
Under an environment of 25 ° C., 5 mg of each of the compounds shown in Table A was added to 100 ml of iso-butanol and stirred for 3 hours. Then, it was visually confirmed whether or not the compound was completely dissolved. What was not done was set as x. Those not completely dissolved correspond to the compound of the present invention.

Example 2
<< Production of Organic EL Element 2-1 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After forming the film by spin coating, the film was dried at 200 ° C. for 1 hour to provide a 20 nm-thick hole transport layer.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 1 dissolved in 10 ml of toluene was formed on the hole transport layer by spin coating at 1500 rpm for 30 seconds. In a nitrogen atmosphere, ultraviolet light was irradiated for 180 seconds to perform photopolymerization / crosslinking to form a second hole transport layer having a thickness of about 20 nm.

  On this 2nd hole transport layer, the film which melt | dissolved 100 mg PVK and 10 mg dopant 4 in 10 ml toluene was formed into a film by the spin coat method on 1000 rpm and 30 second conditions. It vacuum-dried at 120 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, a solution obtained by dissolving 50 mg of the electron transport material 1 in 10 ml of 1-butanol was formed on this light emitting layer by spin coating under a condition of 5000 rpm for 30 seconds. It vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 15 nm.

Subsequently, this substrate is fixed to a substrate holder of a vacuum deposition apparatus, the vacuum chamber is decompressed to 4 × 10 ⁻⁴ Pa, lithium fluoride 1.0 nm is deposited as a cathode buffer layer, and aluminum 110 nm is deposited as a cathode to form a cathode. Then, an organic EL element 2-4 was produced.

<< Production of Organic EL Elements 2-1 to 2-12 >>
In the production of the organic EL element 2-4, an attempt was made to produce each of the organic EL elements in the same manner as in the organic EL element 2-4 except that PVK was replaced with the compounds shown in Table 2. In 2-3, when the electron transport layer was applied, the light emitting layer melted, and the device could not be formed. Organic EL elements 2-5 to 2-12 could be prepared in the same manner as organic EL element 2-4.

<< Evaluation of Organic EL Elements 2-4 to 2-12 >>
When evaluating the obtained organic EL elements 2-4 to 2-12, the non-light emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material in the periphery, and this is placed on the cathode to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 2 and 3 was formed and evaluated.

  FIG. 2 is a schematic diagram of the lighting device, and the organic EL element 201 is covered with a glass cover 202. Note that the sealing operation with the glass cover was performed in a glove box in a nitrogen atmosphere without bringing the organic EL element 201 into contact with the atmosphere (in a high purity nitrogen gas atmosphere with a purity of 99.999% or more).

  FIG. 3 is a cross-sectional view illustrating one embodiment of the lighting device of the present invention. In FIG. 3, reference numeral 205 denotes a cathode, 206 denotes an organic EL layer, and 207 denotes a glass substrate with a transparent electrode. The glass cover 202 is filled with nitrogen gas 208 and a water catching agent 209 is provided.

  Next, the external extraction quantum efficiency and emission lifetime were measured as follows.

(External extraction quantum efficiency)
About the produced organic EL element, the external extraction quantum efficiency (%) when applying a constant current of ^2.5 mA / cm ² at 23 ° C. in a dry nitrogen gas atmosphere was measured.

  For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used in the same manner.

  The measurement results of the external extraction quantum efficiency in Table 2 are expressed as relative values when the measurement value of the organic EL element 2-4 is 100.

(lifespan)
When driven at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ 0.5). As an index of life.

  For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.

  The lifetime measurement results in Table 2 are expressed as relative values when the organic EL element 2-4 is 100.

  The obtained results are shown in Table 2.

  From Table 2, it is clear that the organic EL device of the present invention exhibits high external extraction quantum efficiency, a low driving voltage, and a long emission lifetime as compared with the comparison.

Example 3
<< Production of Organic EL Element 3-4 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After forming the film by spin coating, the film was dried at 200 ° C. for 1 hour to provide a 20 nm-thick hole transport layer.

  The substrate 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 formed on the hole transport layer by spin coating at 1500 rpm for 30 seconds. In a nitrogen atmosphere, ultraviolet light was irradiated for 180 seconds to perform photopolymerization / crosslinking to form a second hole transport layer having a thickness of about 20 nm.

  On this second hole transport layer, a solution prepared by dissolving 100 mg of PVK and 10 mg of dopant 5 in 10 ml of toluene was formed by spin coating at 1000 rpm for 30 seconds. It vacuum-dried at 120 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, a solution obtained by dissolving 50 mg of the electron transporting material 2 in 10 ml of iso-butanol was formed on this light emitting layer by spin coating at 5000 rpm for 30 seconds. It vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 20 nm.

Subsequently, this substrate is fixed to a substrate holder of a vacuum deposition apparatus, the vacuum chamber is decompressed to 4 × 10 ⁻⁴ Pa, lithium fluoride 1.0 nm is deposited as a cathode buffer layer, and aluminum 110 nm is deposited as a cathode to form a cathode. Then, an organic EL element 3-4 was produced.

<< Production of Organic EL Elements 3-1 to 3-10 >>
In the production of the organic EL element 3-4, an attempt was made to produce each of the organic EL elements in the same manner as in the organic EL element 3-4 except that PVK was replaced with the compounds shown in Table 3. In 3-3, when the electron transport layer was applied, the light emitting layer melted, and the device could not be formed. Organic EL elements 3-5 to 3-10 were prepared in the same manner as organic EL element 3-4.

  Organic EL elements 3-4 to 3-10 were produced.

<< Evaluation of Organic EL Elements 3-4 to 3-10 >>
When evaluating the obtained organic EL elements 3-4 to 3-10, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material in the periphery, and this is placed on the cathode to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 2 and 3 was formed and evaluated.

  FIG. 2 is a schematic diagram of the lighting device, and the organic EL element 201 is covered with a glass cover 202. Note that the sealing operation with the glass cover was performed in a glove box in a nitrogen atmosphere without bringing the organic EL element 201 into contact with the atmosphere (in a high purity nitrogen gas atmosphere with a purity of 99.999% or more).

  FIG. 3 is a cross-sectional view illustrating one embodiment of the lighting device of the present invention. In FIG. 3, reference numeral 205 denotes a cathode, 206 denotes an organic EL layer, and 207 denotes a glass substrate with a transparent electrode. The glass cover 202 is filled with nitrogen gas 208 and a water catching agent 209 is provided.

  Next, the external extraction quantum efficiency and emission lifetime were measured as follows.

(External extraction quantum efficiency)
About the produced organic EL element, external extraction quantum efficiency (%) when ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured.

  For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used in the same manner.

  The measurement results of the external extraction quantum efficiency in Table 1 are expressed as relative values when the measurement value of the organic EL element 3-4 is 100.

(lifespan)
When driven at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ 0.5). As an index of life.

  For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.

  Moreover, the measurement result of the lifetime of Table 1 was represented by the relative value when the organic EL element 3-4 was set to 100.

  The obtained results are shown in Table 3.

  From Table 3, it is clear that the organic EL device of the present invention exhibits a high external extraction quantum efficiency, a low driving voltage, and a long emission lifetime as compared with the comparison.

Example 4
<< Production of organic EL full-color display device >>
FIG. 1 shows a schematic configuration diagram of an organic EL full-color display device. After patterning at a pitch of 100 μm on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by forming a 100 nm ITO transparent electrode (102) on a glass substrate 101 as an anode, non-between the ITO transparent electrodes on this glass substrate. A photosensitive polyimide partition 103 (width 20 μm, thickness 2.0 μm) was formed by photolithography.

  A hole injection layer composition having the following composition is ejected and injected between polyimide partition walls on the ITO electrode using an inkjet head (manufactured by Epson; MJ800C), irradiated with ultraviolet light for 2 minutes, and dried at 60 ° C. for 10 minutes. A hole injection layer 104 having a thickness of 40 nm was produced by the treatment.

  On the hole injection layer, the following blue light-emitting layer composition, green light-emitting layer composition, and red light-emitting layer composition were similarly discharged and injected using an inkjet head, and dried at 60 ° C. for 10 minutes. Each light emitting layer (105B, 105G, 105R) was formed. Finally, Al (106) was vacuum-deposited as a cathode so as to cover the light emitting layer 105, and an organic EL element was produced.

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

(Hole injection layer composition)
Hole transport material 1 20 parts by mass cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (blue light emitting layer composition)
Compound Example 1-1 0.7 parts by mass of dopant 4 0.04 parts by mass of cyclohexylbenzene 50 parts by mass of isopropyl biphenyl 50 parts by mass (green light emitting layer composition)
Compound Example 1-1 0.7 parts by mass of dopant 1 0.04 parts by mass of cyclohexylbenzene 50 parts by mass of isopropyl biphenyl 50 parts by mass (red light emitting layer composition)
Compound Example 1-1 0.7 parts by mass of dopant 2 0.04 parts by mass of cyclohexylbenzene 50 parts by mass of isopropyl biphenyl 50 parts by mass (electron transport layer composition)
Electron transport material 1 20 parts by mass 1-butanol 50 parts by mass Isopropyl biphenyl 50 parts by mass

Example 5
<< Production of White Organic EL Element 5-1 >>
A hole transport layer / second hole transport layer was formed on the transparent electrode substrate of Example 2 by the spin coating method in the same manner as in Example 2, and 100 mg of Compound Example 1-1, 10 mg as a light emitting layer was further formed. A solution prepared by dissolving 5 mg of dopant 5 and 0.1 mg of dopant 3 in 10 ml of toluene was formed into a film by spin coating under conditions of 1000 rpm and 30 seconds. It vacuum-dried at 120 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, in the same manner as in Example 2, an electron transport layer, a lithium fluoride layer, and an aluminum cathode were formed to produce a white light-emitting organic EL element 5-1. The obtained organic EL element 5-1 was sealed in the same manner as in Example 2.

  When this organic EL element 5-1 was energized, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, it turned out that white light emission is obtained similarly even if it replaces a host compound with the other compound which concerns on this invention.

Example 6
<< Production of Organic EL Element 6-1 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, 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.

  This substrate was transferred to a nitrogen atmosphere, and a mixed solution prepared by dissolving 50 mg of the hole transporting material 3 and 5 mg of the hole transporting material 4 in 10 ml of toluene on the hole transporting layer was positive at 1500 rpm for 30 seconds. A thin film was formed by spin coating on the hole 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.

  On this second hole transport layer, a thin film was formed by spin coating using a solution obtained by dissolving 100 mg of Comparative Compound 3 and 10 mg of (162) in 10 ml of toluene at 600 rpm for 30 seconds. 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 material 3 in 10 ml of hexafluoroisopropanol (HFIP) at 2000 rpm for 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and was set as the 1st electron carrying layer.

Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, 200 mg of the electron transport material 2 was put into a molybdenum resistance heating boat, and attached to the vacuum vapor deposition apparatus. After depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing the electron transport material 2 is energized and heated, and deposited on the first electron transport layer at a deposition rate of 0.1 nm / second. Further, a second electron transport layer having a thickness of 20 nm was provided.

  Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the organic EL element 6-1 was produced.

  In the production of the organic EL element 6-1, an organic EL element 6-2 was produced in the same manner as the organic EL element 6-1, except that the comparative compound 3 was replaced with Compound Example 1-2.

<< Evaluation of Organic EL Elements 6-1 and 6-2 >>
When evaluating the obtained organic EL elements 6-1 and 6-2, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material in the periphery, and this is placed on the cathode to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 2 and 3 was formed and evaluated.

  FIG. 2 is a schematic diagram of the lighting device, and the organic EL element 201 is covered with a glass cover 202. The sealing operation with the glass cover was performed in a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more) without bringing the organic EL element 201 into contact with the atmosphere.

  FIG. 3 is a cross-sectional view illustrating one embodiment of the lighting device of the present invention. In FIG. 3, reference numeral 205 denotes a cathode, 206 denotes an organic EL layer, and 207 denotes a glass substrate with a transparent electrode. The glass cover 202 is filled with nitrogen gas 208 and a water catching agent 209 is provided.

  Next, the external extraction quantum efficiency and emission lifetime were measured as follows.

(External extraction quantum efficiency)
About the produced organic EL element, external extraction quantum efficiency (%) when ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used in the same manner. Moreover, the measurement result of the external extraction quantum efficiency in Table 4 was expressed as a relative value when the measurement value of the organic EL element 2-4 was set to 100.

(lifespan)
When driven at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ 0.5). As an index of life. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used. Moreover, the measurement result of the lifetime of Table 4 was represented by the relative value when the organic EL element 6-1 was set to 100.

  The results obtained are shown in Table 4.

Claims (20)

A method for producing an organic electroluminescence device having a light emitting layer and an electron transport layer,
A compound having a partial structure represented by the following general formula (1) and having a solubility in iso-butanol at 25 ° C. under normal pressure of 0.05 g / L or less, and represented by the following general formula (2) Forming the light emitting layer containing a metal complex compound;
Forming the electron transport layer on the light emitting layer by a wet method;
The manufacturing method of the organic electroluminescent element characterized by having.
(In the general formula (1), Ar represents a divalent arylene group, Ya represents any of O, S, and N-Ra, Yb represents any of O, S, and N-Rb, and Ya and Yb may be different or the same, Ra and Rb each represent a substituent or a bond, and RA and RB each represent an aromatic hydrocarbon ring group, an aromatic heterocyclic group, an alkyl group, an alkenyl group, or an acyloxy group, when RA and RB have multiple, they are _.Xa 1 _{~Xa 8} and _Xb 1 _{~Xb 8} may be the same or different from each other represent C-Ra ₁ or a nitrogen atom, Ra ₁ is hydrogen atom, a substituent or If the .C-Ra ₁ representing a bond there are a plurality, Ra ₁ may be the same or different from each other.)
(In General Formula (2), X ₄ represents a carbon atom or a nitrogen atom, and has an aromatic hydrocarbon ring group having a substituent or an aromatic heterocyclic group having a substituent. Y is a carbon atom or nitrogen. Represents an atom, A represents a 6-membered aromatic hydrocarbon ring or aromatic heterocycle, B represents a 5-membered or 6-membered aromatic heterocycle, and X ₁ -L ₁ -X ₂ represents a bidentate arrangement. X ₁ and X ₂ each independently represents a carbon atom, a nitrogen atom or an oxygen atom, L ₁ represents an atomic group which forms a bidentate ligand together with X ₁ and X ₂ , m1 1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, but m1 + m2 is 2 or 3. M as a central metal represents a group 8-10 metal in the periodic table. ) The said general formula (2) is represented by the following general formula (3), The manufacturing method of the organic electroluminescent element of Claim 1 characterized by the above-mentioned.
(In the general formula (3), Z is an aromatic hydrocarbon ring group or table to an aromatic heterocyclic group having a substituent. A is a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring having a substituent X ₁ -L ₁ -X ₂ represents a bidentate ligand, X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom, and L ₁ represents ₂ together with X ₁ and X 2. Represents an atomic group forming a ligand of a locus, m1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, and m1 + m2 is 2 or 3. A central metal. M represents a metal of group 8 to 10 in the periodic table.) The method for producing an organic electroluminescent element according to claim 2, wherein A in the general formula (3) represents a benzene ring. The method for producing an organic electroluminescent element according to claim 2 or 3, wherein the metal complex compound represented by the general formula (3) is composed of only the same ligand. M of the said General formula (3) is iridium or platinum, The manufacturing method of the organic electroluminescent element of any one of Claims 2-4 characterized by the above-mentioned. The molecular weight of the compound having the partial structure represented by the general formula (1) is 700 to 3000, The method for producing an organic electroluminescent element according to any one of claims 1 to 5. Ar in the said General formula (1) is represented by following General formula (4), The manufacturing method of the organic electroluminescent element of any one of Claims 1-6 characterized by the above-mentioned.
(In the general formula (4), Yc represents O, S, one of the N-Rc, Rc is _.Xc 1 Xc ₈ representing a substituent represents a carbon atom or a nitrogen atom, the same even if different from each other When any of Xc _{1 to} Xc ₈ is a carbon atom, Rc ₁ to Rc ₈ bonded to the carbon atom represents a hydrogen atom or a substituent, and any of Xc _{1 to} Xc ₈ is nitrogen. In the case of an atom, Rc ₁ to Rc ₈ bonded to the nitrogen atom each represent an unshared electron pair, and at least two of Rc and Rc _{1 to} Rc ₈ are used for connection.) 8. The method for producing an organic electroluminescent element according to claim 7, wherein all of Xc _{1 to} Xc ₈ in the general formula (4) are carbon atoms. Yc is O or N-Rc, The manufacturing method of the organic electroluminescent element of Claim 7 or 8 characterized by the above-mentioned. Yc is N-Rc, The manufacturing method of the organic electroluminescent element of Claim 9 characterized by the above-mentioned. The method for producing an organic electroluminescent element according to claim 7, wherein Rc ₃ and Rc ₆ in the general formula (4) are used for connection. Ar in the said General formula (1) is represented by following General formula (5), The manufacturing method of the organic electroluminescent element of any one of Claims 1-6 characterized by the above-mentioned.
(In General Formula (5), Xd _{1 to} Xd ₆ represent a carbon atom or a nitrogen atom, and may be different or the same. When any of Xd _{1 to} Xd ₆ is a carbon atom, Rd ₁ to Rd ₆ bonded to each other represent a hydrogen atom or a substituent, and when any of Xd _{1 to} Xd ₆ is a nitrogen atom, Rd ₁ to Rd ₆ bonded to the nitrogen atom are each not shared. Represents an electron pair, and at least two of Rd _{1 to} Rd ₆ are used for connection.) The method for producing an organic electroluminescent element according to claim 12, wherein all of Xd _{1 to} Xd ₆ in the general formula (5) are carbon atoms. 14. The method for producing an organic electroluminescence element according to claim 12, wherein Rd ₁ and Rd ₃ in the general formula (5) are used for connection. Ya in the said General formula (1) represents N-Ra, The manufacturing method of the organic electroluminescent element of any one of Claims 1-14 characterized by the above-mentioned. Ra in the said General formula (1) is used for the connection with Ar, The manufacturing method of the organic electroluminescent element of Claim 15 characterized by the above-mentioned. The process for forming the electron transport layer is performed by applying a solution in which an electron transport material is dissolved in a solvent containing alcohols, and manufacturing the organic electroluminescence device according to any one of claims 1 to 16. Method. The method for producing an organic electroluminescent element according to claim 1, wherein in the step of forming the electron transport layer, a solution in which an electron transport material is dissolved in n-butanol is applied. The method for producing an organic electroluminescent element according to claim 1, wherein in the step of forming the electron transport layer, a solution in which an electron transport material is dissolved in iso-butanol is applied. The method for producing an organic electroluminescent element according to claim 1, wherein in the step of forming the light emitting layer, the light emitting layer is formed by a wet method.