JP2016213312A - Material for organic electroluminescent element, organic electroluminescent element, and organometallic complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material for organic electroluminescent element capable of improving the emission lifetime and voltage rise during element drive, while suppressing occurrence of a dark spot after element drive, and to provide an organic electroluminescent element, and an organometallic complex in which the antioxidant action of the complex is improved.SOLUTION: In a material for organic electroluminescent element containing a neutral organometallic complex, the organometallic complex has at least two ligands having an intramolecular hydrogen bondable substituent group. One intramolecular hydrogen bondable substituent group of the ligand is substituted to a position capable of forming a hydrogen bond with an intramolecular hydrogen bondable substituent group of other ligand constituting the same metallic complex molecule.SELECTED DRAWING: None

Description

  The present invention relates to an organic electroluminescent element material, an organic electroluminescent element, and an organometallic complex, and particularly, an organic material that can improve light emission lifetime and voltage increase during element driving, and can suppress generation of dark spots after element driving. The present invention relates to a material for an electroluminescence element and an organic electroluminescence element. Moreover, it is related with the organometallic complex which improved the antioxidant action of the complex.

Organometallic complexes (hereinafter also simply referred to as “metal complexes”), which are typical organic electronics materials, are used in various organic electronics devices as charge transport materials, light-emitting materials, organic semiconductors, and the like. Since the characteristics of the metal complex have a great influence on the performance of the organic electronic device, it is extremely important to prepare a metal complex suitable for the purpose as one means for improving the device characteristics. However, the properties of organic compounds often change dramatically depending on the combination of structure and substituents, and metal complexes are no exception.
For example, a metal complex used as a light-emitting material in an organic electroluminescence element (hereinafter also referred to as an “organic EL element”), which is one of organic electronics elements, controls the emission wavelength, lifetime, productivity, etc. of the element. Many problems remain to be improved in these characteristics.

  An organometallic complex is a compound composed of a central metal and an organic ligand, and has so far succeeded in controlling the characteristics required for the device by changing the structure of the ligand. However, this method is an approach for obtaining a solution from an infinite number of combinations of the basic skeleton of the ligand and substituents, and there is also an aspect that cannot be said to be an optimal method for obtaining necessary characteristics.

On the other hand, in Patent Document 1 and Patent Document 2 in recent years, attention has been paid to the number of ligands apart from the above approach, and an invention has been made in which a new type metal complex using a cage-like ligand is used for an organic EL element. ing.
However, cage-like ligands are difficult to synthesize and have limited structural freedom, so the positional relationship between the central metal and the ligand is often not optimal and is sufficient as a metal complex. Therefore, the performance of an element including these has not necessarily reached a satisfactory level.

  Therefore, the organometallic complex used as the organic electronics element material is easy to synthesize and, for example, when used in an organic EL element, emission lifetime, voltage increase during element driving, generation of dark spots after element driving There is a demand for organometallic complexes that can further improve various performances and disadvantages such as the above-mentioned approaches from the viewpoint of the combination of the basic skeleton and substituents of the ligand and the steric structure of the ligand. Research and development from a different viewpoint is required.

International Publication No. 2011/004639 JP 2009-267255 A

  The present invention has been made in view of the above-described problems and circumstances, and the problem to be solved is that it is possible to improve the light emission lifetime and the voltage increase during element driving, and to suppress the generation of dark spots after element driving. It is to provide an organic electroluminescent element material and an organic electroluminescent element. Moreover, it is providing the organometallic complex which improved the antioxidant action of the complex.

In order to solve the above-mentioned problems, the present inventor has gone through the search for an infinite number of combinations of the basic skeleton of the ligand and the substituent, and studied a new ligand structure that can improve the defects of the cage ligand. As a result, an invention relating to an organometallic complex capable of forming an intramolecular hydrogen bond between ligands, which has not been known so far, has been completed.
That is, the said subject which concerns on this invention is solved by the following means.

1. A material for an organic electroluminescence device containing a neutral organometallic complex,
The organometallic complex has at least two ligands having a substituent capable of intramolecular hydrogen bonding, and
One substituent capable of hydrogen bonding in the molecule of the ligand is substituted at a position where a hydrogen bond can be formed with a substituent capable of hydrogen bonding in the molecule of another ligand constituting the same metal complex molecule. A material for an organic electroluminescence device, characterized by comprising:

  2. 2. The material for an organic electroluminescence element according to item 1, wherein the number of ligands constituting the organometallic complex is at least three.

  3. 3. The organic electroluminescent element material according to item 1 or 2, wherein three ligands constituting the organometallic complex form an intramolecular hydrogen bond.

  4). The atom on the ligand to which the substituent capable of intramolecular hydrogen bonding is bonded is adjacent to the atom on the ligand covalently bonded to the central metal of the organometallic complex. The organic electroluminescent element material according to any one of items 1 to 3.

5. An organic electroluminescent device having one or more organic layers including a light emitting layer between at least one pair of an anode and a cathode,
Any of the said organic layers contains the organic electroluminescent element material as described in any one of 1st term | claim to 4th term | claim, The organic electroluminescent element characterized by the above-mentioned.

  6). 6. The organic electroluminescent element according to item 5, wherein the light emitting layer contains the material for an organic electroluminescent element.

〔式中、Ｍは、Ｉｒ、Ｐｔ、Ｒｈ、Ｒｕ、Ａｇ、Ｃｕ又はＯｓを表す。Ａ_１、Ａ_２、Ｂ_１、及びＢ_２は、各々、炭素原子又は窒素原子を表す。環Ｚ_１は、Ａ_１及びＡ_２と共に形成される６員の芳香族炭化水素環又は５員若しくは６員の芳香族複素環を表す。環Ｚ_２は、Ｂ_１及びＢ_２と共に形成される５員又は６員の芳香族複素環を表す。環Ｚ_１及び環Ｚ_２は、置換基を有していてもよく、更に置換基同士が結合して縮環構造を形成していてもよい。また、各々の配位子の置換基が互いに結合して、配位子同士が連結していてもよい。Ｌ′は、Ｍに配位したモノアニオン性の二座配位子を表す。ｍ′は、０〜２の整数を表す。ｎ′は、１〜３の整数を表す。ｍ′＋ｎ′は、２又は３である。ｍ′及びｎ′が２以上のとき、環Ｚ_１及び環Ｚ_２で表される配位子及びＬ′は各々同じでも異なっていてもよい。〕 7). Item 5 or 6, wherein the light emitting layer contains a phosphorescent organometallic complex having a structure represented by the following general formula (DP) as the material for the organic electroluminescence element. The organic electroluminescent element of the item.

[Wherein M represents Ir, Pt, Rh, Ru, Ag, Cu or Os. A ₁ , A ₂ , B ₁ , and B ₂ each represent a carbon atom or a nitrogen atom. Ring Z ₁ represents a 6-membered aromatic hydrocarbon ring or 5-membered or 6-membered aromatic heterocycle formed together with A ₁ and A ₂ . Ring Z ₂ represents a 5-membered or 6-membered aromatic heterocycle formed together with B ₁ and B ₂ . Ring Z ₁ and ring Z ₂ may have a substituent, and the substituents may be bonded to each other to form a condensed ring structure. Moreover, the substituent of each ligand may mutually couple | bond together and the ligands may connect. L ′ represents a monoanionic bidentate ligand coordinated to M. m ′ represents an integer of 0 to 2. n ′ represents an integer of 1 to 3. m ′ + n ′ is 2 or 3. When m ′ and n ′ are 2 or more, the ligands represented by ring Z ₁ and ring Z ₂ and L ′ may be the same or different. ]

  8). The organic electroluminescent element according to any one of items 5 to 7, wherein an Ir complex is contained as the phosphorescent organic metal complex contained in the light emitting layer.

  9. The organic electroluminescent element according to any one of Items 5 to 8, wherein the organic layer is formed by a wet process.

10. An organometallic complex having the same structure as the organometallic complex contained in the material for an organic electroluminescent element according to any one of Items 1 to 4,
Having at least two ligands having substituents capable of intramolecular hydrogen bonding; and
One substituent capable of hydrogen bonding in the molecule of the ligand is substituted at a position where a hydrogen bond can be formed with a substituent capable of hydrogen bonding in the molecule of another ligand constituting the same metal complex molecule. An organometallic complex characterized in that

Provided are an organic electroluminescence element material and an organic electroluminescence element that can improve the light emission lifetime and the voltage increase during element driving, and can suppress the generation of dark spots after element driving by the above-described means of the present invention. Can do. Moreover, the organometallic complex which improved the antioxidant action of the complex can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
As one of the means for improving the stability of the complex, for example, in the case of a complex formed of two ligands and a central metal complex, the ligands are connected to each other with a single ligand and the central metal. There is a technique for forming a complex.
The principle of reducing the constituent elements of the complex and improving the stability (decomposition resistance) of the complex can be explained by a change in entropy. The following describes an example in which the number of constituent elements of the complex is reduced and the entropy effect is utilized for the stability of the complex.

  Table A shows the complex stability of various cadmium amine complexes decomposed into thermodynamic parameters.

  For example, No. 1 which is a chelate complex. 3 (cadmium ethylenediamine complex) and No. 3 which is a non-chelate complex. Comparing the two complexes (cadmium 2-methylamine complex), both have the same enthalpy (which may be interpreted as adsorption power), but the entropy is greatly different. This difference in entropy term, that is, 5.8 kJ / mol, is the difference in stability between chelate and non-chelate. This is a large stabilization energy corresponding to 21% of the Gibbs free energy of the complex of 2.

  It can be understood sensuously that chelate complexes are stable, and their stability is generally well known, but it is not surprisingly known that most of this source is an entropy effect. So where does this entropy effect come from? Entropy can also be expressed as the product of the Boltzmann distribution and the number of components. In the case of a chelate complex, it is easy to understand by considering this change in the number of components.

  As shown in equation (a), No. In the case of 2 non-chelate complexes, the number of components before complex formation is 3, and the number of components after complex formation is also 3. On the other hand, as shown in equation (b), No. In the case of 3 chelate complexes, the number of components before complex formation is 2, and the number of components after complex formation is 3, indicating that the number of components increases. That is, entropy increases.

  Next, how much this chelate complex formation affects the durability will be described with specific examples (see KONICA TECHNICICAL REPORT p. 83-p. 86, vol. 14 (2001)).

  Konica Photochelate (registered trademark), a chelate dye transfer printing material, has a chelate-forming reaction when a dye with a structure that can be a ligand is diffused and transferred to a metal ion compound in the image receiving layer. This is an image forming system in which a chelate dye is formed and fixed, but this formed image dye (chelate complex dye) is not only fixed but also has improved durability and light resistance and heat resistance. Print.

  This effect is shown by comparison between FIG. 7 (A) and FIG. 7 (B). FIG. 7 is an example showing color image fastness using a chelate complex dye. FIG. 7 shows changes in the density of cyan, magenta, and yellow dyes represented by C, M, and Y, respectively, as a result of the dark blue color experiment at 65 ° C. FIG. 7 (A) shows a Konica photochelate using a chelate complex dye, and FIG. 7 (B) shows a typical normal dye thermal transfer. The difference is obvious at a glance. It can be seen that the pigment is present without fading.

  That is, in the photochelate, the entropy of the film containing the dye is originally larger at the stage of forming the image, and the entropy effect produces the stability of the film. It can be considered that it meets the requirements.

  Thus, by effectively utilizing the entropy effect, a film formed mainly of an organic material can increase Gibbs free energy in its initial state, and the increase effect is long-term. It can be said that it is large enough to suppress fluctuations even under severe deterioration conditions such as storage at high temperatures.

As described above, conventionally, a method has been used in which the ligands are covalently bonded and the stability of the complex is enhanced by the entropy effect generated by reducing the number of ligands during complex formation. As a result of intensive investigations on the method for further improving the stability of the complex, the present inventors have found that the ligands are linked with an intramolecular hydrogen bond, so that the stability is higher than that of the organometallic complex connected with a covalent bond. As a result, the anti-oxidation effect of the organometallic complex is improved, and when the organometallic complex is used in a material for an organic electroluminescence element and an organic electroluminescence element, the emission lifetime and the voltage increase during driving of the element are improved. And it discovered that generation | occurrence | production of the dark spot after element drive was suppressed, and came to this invention.
For example, there is a high possibility that the hydroxy group of a metal complex having a hydroxy group has been arranged at a position where an intramolecular hydrogen bond can be formed by chance, but there has been no study of its effect. It is considered that the present invention has been completed by elucidating the effects described above for the first time in the present invention.

The intramolecular hydrogen bond between the ligands of the complex will be described with reference to compound examples and comparative compounds.
Comparative 1 which is a conventionally known dopant for organic EL has excellent characteristics as a dopant, and it is considered that the arrangement of the ligand and the central metal maintains a good positional relationship. On the other hand, since Comparative 2 is a structure in which ligands are bonded by a covalent bond, the structure is distorted when considering the entire metal complex, and the ligand and the central metal maintain a good positional relationship. Is difficult. In contrast, the compound of the present invention has a hydrogen-bonding substituent at a position where an intramolecular hydrogen bond can be formed, and an intramolecular hydrogen bond having a higher degree of freedom than a covalent bond is used as a means for binding between ligands. Since it is used, it is thought that the structure which maintains the positional relationship between the ligand of Comparative 1 and the central metal can be maintained. From the above, the compound of the present invention using an intramolecular hydrogen bond is required as a structure capable of exhibiting the stabilization due to the entropy effect while utilizing the characteristics of Comparative Example 1.
In addition, although the following is a schematic diagram, the same effect can be confirmed also by examination of the molecular structure by the molecular calculation mentioned later.

Schematic diagram showing an example of a display device composed of organic EL elements Schematic diagram of an active matrix display device Schematic showing the pixel circuit Schematic diagram of a passive matrix display device Schematic of lighting device Schematic diagram of lighting device An example of color image fastness using a chelate complex dye NMR spectrum chart of Compound D-102 Thermal analysis chart of Compound D-102

The organic electroluminescent device material of the present invention is a material for an organic electroluminescent device containing a neutral organometallic complex, and the organometallic complex has a ligand having a substituent capable of intramolecular hydrogen bonding. One of the substituents having at least two and capable of intramolecular hydrogen bonding of the ligand has a hydrogen bond with a substituent capable of intramolecular hydrogen bonding of another ligand constituting the same metal complex molecule. It is substituted at a position where it can be formed.
This feature is a technical feature common to or corresponding to the inventions according to claims 1 to 10.

Although various forms can be taken as an embodiment of the present invention, it is preferable that the number of ligands constituting the organometallic complex is three from the viewpoint of manifesting the effect of the present invention.
In addition, it is preferable from the viewpoint of the stability of the organometallic complex that the three ligands constituting the organometallic complex form an intramolecular hydrogen bond.
Furthermore, the atom on the ligand to which the substituent capable of intramolecular hydrogen bonding is bonded is adjacent to the atom on the ligand covalently bonded to the central metal of the organometallic complex. From the viewpoints of further stability of the organometallic complex, ease of synthesis, and the like.

The organic electroluminescent device of the present invention is an organic electroluminescent device having one or a plurality of organic layers including a light emitting layer between at least one pair of an anode and a cathode, and any one of the organic layers is the organic It contains an electroluminescent element material.
Although various forms can be taken as embodiments of the present invention, it is preferable that the light emitting layer contains the material for an organic electroluminescence element from the viewpoint of manifesting the effects of the present invention.
In addition, the phosphorescent organometallic complex includes that the phosphorescent layer contains a phosphorescent organometallic complex having a structure represented by the general formula (DP) as the material for the organic electroluminescence element. From the viewpoint of stability and the like, it is preferable.
In addition, it is preferable that an Ir complex is contained as the phosphorescent organometallic complex contained in the light emitting layer because the effects of the present invention are more remarkably exhibited.
Furthermore, the organic layer is preferably formed by a wet process.

  The organometallic complex of the present invention is an organometallic complex having the same structure as the organometallic complex contained in the material for an organic electroluminescence element, and includes at least a ligand having a substituent capable of intramolecular hydrogen bonding. One of the two substituents that can form an intramolecular hydrogen bond of the ligand can form a hydrogen bond with an intramolecular hydrogen bondable substituent of another ligand that constitutes the same metal complex molecule. It is characterized by being substituted at various positions.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

[Materials for organic electroluminescence elements]
The organic electroluminescence element material of the present invention (hereinafter also simply referred to as “organic EL element material”) is an organic electroluminescence element material containing a neutral organometallic complex, and the organometallic complex is And at least two ligands having substituents capable of intramolecular hydrogen bonding, and one of the ligands capable of intramolecular hydrogen bonding is another arrangement constituting the same metal complex molecule. The ligand is characterized by being substituted at a position capable of forming a hydrogen bond with a substituent capable of forming an intramolecular hydrogen bond.

In the present invention, the hydrogen bond refers to a lone pair of electrons such as nitrogen, oxygen, sulfur, fluorine, and a π-electron system in which a hydrogen atom covalently bonded to an atom (negative atom) having a large electronegativity is located in the vicinity. This is a non-covalent attractive interaction. There are hydrogen bonds that work between different molecules (intermolecular force) and those that work between different parts of a single molecule (intramolecular). In the present invention, hydrogen bonds formed within a molecule, Intended for hydrogen bonds that can be formed in metal complex molecules. Since the complex of the invention has a relatively large molecular weight and many complex structures, it is easy to think of it by referring to, for example, hydrogen bonds formed in DNA or protein molecules. Specifically, the distance between substituents in which hydrogen bonds act is often about 500 pm or less in DNA, and more specifically about 400 pm or less in many cases. You can refer to this value. For example, when a hydrogen bond is formed between a hydroxy group formed from an oxygen atom (A) and a hydrogen atom and an oxygen atom (B) of another substituent, the oxygen atom (A) and the oxygen atom (B) The relative distance between them will be taken into account. The relative distance can be obtained using molecular orbital calculation (gaussian 09) or the like.

<< Compound having structure represented by general formula (DP) >>
The organic electroluminescent element material of the present invention is an organic electroluminescent element material containing a neutral organometallic complex, wherein the organometallic complex has a structure represented by the following general formula (DP) It is preferable that
In addition, the organic electroluminescent element material of this invention may contain compounds other than the compound which has a structure represented by the following general formula (DP) within the range which does not inhibit the effect of this invention.

〔式中、Ｍは、Ｉｒ、Ｐｔ、Ｒｈ、Ｒｕ、Ａｇ、Ｃｕ又はＯｓを表す。Ａ_１、Ａ_２、Ｂ_１、及びＢ_２は、各々、炭素原子又は窒素原子を表す。環Ｚ_１は、Ａ_１及びＡ_２と共に形成される６員の芳香族炭化水素環又は５員若しくは６員の芳香族複素環を表す。環Ｚ_２は、Ｂ_１及びＢ_２と共に形成される５員又は６員の芳香族複素環を表す。環Ｚ_１及び環Ｚ_２は、置換基を有していてもよく、更に置換基同士が結合して縮環構造を形成していてもよい。また、各々の配位子の置換基が互いに結合して、配位子同士が連結していてもよい。Ｌ′は、Ｍに配位したモノアニオン性の二座配位子を表す。ｍ′は、０〜２の整数を表す。ｎ′は、１〜３の整数を表す。ｍ′＋ｎ′は、２又は３である。ｍ′及びｎ′が２以上のとき、環Ｚ_１及び環Ｚ_２で表される配位子及びＬ′は各々同じでも異なっていてもよい。〕

[Wherein M represents Ir, Pt, Rh, Ru, Ag, Cu or Os. A ₁ , A ₂ , B ₁ , and B ₂ each represent a carbon atom or a nitrogen atom. Ring Z ₁ represents a 6-membered aromatic hydrocarbon ring or 5-membered or 6-membered aromatic heterocycle formed together with A ₁ and A ₂ . Ring Z ₂ represents a 5-membered or 6-membered aromatic heterocycle formed together with B ₁ and B ₂ . Ring Z ₁ and ring Z ₂ may have a substituent, and the substituents may be bonded to each other to form a condensed ring structure. Moreover, the substituent of each ligand may mutually couple | bond together and the ligands may connect. L ′ represents a monoanionic bidentate ligand coordinated to M. m ′ represents an integer of 0 to 2. n ′ represents an integer of 1 to 3. m ′ + n ′ is 2 or 3. When m ′ and n ′ are 2 or more, the ligands represented by ring Z ₁ and ring Z ₂ and L ′ may be the same or different. ]

When the ring Z ₁ represents a 6-membered aromatic hydrocarbon ring, the 6-membered aromatic hydrocarbon ring includes a benzene ring, an aromatic hydrocarbon ring in addition to the 6-membered aromatic hydrocarbon ring. Examples of the condensed ring include a naphthalene ring and an anthracene ring.
When the ring Z ₁ represents a 5-membered or 6-membered aromatic heterocyclic ring, examples of the 5-membered aromatic heterocyclic ring include a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a tetrazole ring, an oxazole ring, Examples thereof include an oxazole ring, a thiazole ring, an isothiazole ring, an oxadiazole ring, and a thiadiazole ring.
Of these, a pyrazole ring and an imidazole ring are preferable, and an imidazole ring is more preferable. These rings may be further substituted with a substituent selected from the following substituent group. Preferred as the substituent are an alkyl group and an aryl group, and more preferred are a substituted alkyl group and an unsubstituted aryl group.
Examples of the 6-membered aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyridazine ring, and a pyrazine ring.

Ring Z ₂ is preferably a 5-membered aromatic heterocyclic, aromatic heterocyclic 5-membered, aromatic heterocyclic 5-membered shown by the ring Z1. In particular, at least one of B ₁ and B ₂ is preferably a nitrogen atom.

Examples of the substituent that the ring Z ₁ and the ring Z ₂ may have include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group, a hexyl group, and an octyl group). , Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg, vinyl group, aryl group etc.), alkynyl group (eg, ethynyl group, Propargyl group etc.), aromatic hydrocarbon ring group (aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl Group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, bif Nitryl group, etc.), aromatic heterocyclic groups (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazole- 1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, Dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) ), Quinoxalinyl group, pyridazinyl group, triazinyl Group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyl) Oxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group) 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, naphtho group, etc.) Ruthio 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 (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group) , Phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group) Propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethyl group) Carbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (eg, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group) Pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcal Bonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octyl) Aminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group) Cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), Finyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (For example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group) 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, tri Phenylsilyl group, phenyldiethylsilyl group, etc.).
Of these substituents, preferred are an alkyl group and an aryl group.

Further, the substituents may be bonded to each other to form a condensed ring structure. Moreover, the substituent of each ligand may mutually couple | bond together and the ligands may connect.
L ′ represents a monoanionic bidentate ligand coordinated to M. Examples of the monoanionic bidentate ligand include phenylpyridine having a substituent, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, picolinic acid, acetylacetone, and the like.
m ′ represents an integer of 0 to 2. n ′ represents an integer of 1 to 3. m ′ + n ′ is 2 or 3. When m ′ and n ′ are 2 or more, the ligands represented by ring Z ₁ and ring Z ₂ and L ′ may be the same or different.
M represents Ir, Pt, Rh, Ru, Ag, Cu or Os. Among these, iridium (Ir) and platinum (Pt) are preferable, and iridium is more preferable.

  The general formula (DP) is preferably represented by the following general formula (DP-1) or (DP-2).

一般式（ＤＰ−１）において、Ｍ、Ａ_１、Ａ_２、Ｂ_１、Ｂ_２、環Ｚ_１、Ｌ′、ｍ′及びｎ′は、一般式（ＤＰ）におけるＭ、Ａ_１、Ａ_２、Ｂ_１、Ｂ_２、環Ｚ_１、Ｌ′、ｍ′及びｎ′と同義である。
Ｂ_３〜Ｂ_５は、芳香族複素環を形成する原子群であり、置換基を有していてもよい炭素原子、窒素原子、酸素原子、又は硫黄原子を表す。Ｂ_３〜Ｂ_５が有する置換基としては、前述の一般式（ＤＰ）における環Ｚ_１及び環Ｚ_２が有する置換基と同義の基が挙げられる。

In the general formula (DP-1), M, A ₁ , A ₂ , B ₁ , B ₂ , ring Z ₁ , L ′, m ′ and n ′ are M, A ₁ , A ₂ in the general formula (DP). , B ₁ , B ₂ , ring Z ₁ , L ′, m ′ and n ′.
B < ₃ > -B < ₅ > is an atom group which forms an aromatic heterocyclic ring, and represents the carbon atom, nitrogen atom, oxygen atom, or sulfur atom which may have a substituent. Examples of the substituent that B _{3 to} B ₅ have include the same groups as the substituents that the ring Z ₁ and the ring Z ₂ have in the general formula (DP).

In the general formula (DP-1), the aromatic heterocycle formed by B _{1 to} B ₅ is represented by any one of the following general formulas (DP-1a), (DP-1b), and (DP-1c). It is preferable.

一般式（ＤＰ−１ａ）、（ＤＰ−１ｂ）及び（ＤＰ−１ｃ）において、＊１は、Ａ_２との結合部位を表し、＊２は、Ｍとの結合部位を表す。
Ｒｂ_３〜Ｒｂ_５は、水素原子又は置換基を表し、Ｒｂ_３〜Ｒｂ_５で表される置換基としては、前述の一般式（ＤＰ）における環Ｚ_１及び環Ｚ_２が有する置換基と同義の基が挙げられる。
一般式（ＤＰ−１ａ）におけるＢ_４及びＢ_５は、炭素原子又は窒素原子であり、より好ましくは少なくとも一つは炭素原子である。
一般式（ＤＰ−１ｃ）におけるＢ_３及びＢ_４は、炭素原子又は窒素原子であり、より好ましくは少なくとも一つは炭素原子である。

Formula (DP-1a), in (DP-1b) and (DP-1c), * 1 represents a binding site to _{A 2,} * 2 represents a bonding site with the M.
Rb _{3 to} Rb ₅ represent a hydrogen atom or a substituent, and the substituent represented by Rb _{3 to} Rb ₅ has the same meaning as the substituent that the ring Z ₁ and ring Z ₂ in the general formula (DP) have. The group of is mentioned.
B ₄ and B ₅ in the general formula (DP-1a) are a carbon atom or a nitrogen atom, and more preferably at least one is a carbon atom.
B ₃ and B ₄ in the general formula (DP-1c) are a carbon atom or a nitrogen atom, and more preferably at least one is a carbon atom.

一般式（ＤＰ−２）において、Ｍ、Ａ_１、Ａ_２、Ｂ_１、Ｂ_２、環Ｚ_１、Ｌ′、ｍ′及びｎ′は、一般式（ＤＰ）におけるＭ、Ａ_１、Ａ_２、Ｂ_１、Ｂ_２、環Ｚ_１、Ｌ′、ｍ′及びｎ′は、と同義である。
環Ｚ_２は、Ｂ_１〜Ｂ_３と共に形成される５員の芳香族複素環を表す。
Ａ_３及びＢ_３は、炭素原子又は窒素原子を表す。Ｌ″は、２価の連結基を表す。

In the general formula (DP-2), M, A ₁ , A ₂ , B ₁ , B ₂ , ring Z ₁ , L ′, m ′ and n ′ are M, A ₁ , A ₂ in the general formula (DP). , B ₁ , B ₂ , ring Z ₁ , L ′, m ′ and n ′ are as defined above.
Ring Z ₂ represents a 5-membered aromatic heterocycle formed together with B _{1 to} B ₃ .
A ₃ and B ₃ represent a carbon atom or a nitrogen atom. L ″ represents a divalent linking group.

  Examples of the divalent linking group represented by L ″ include an alkylene group, an alkenylene group, an arylene group, a heteroarylene group, a divalent heterocyclic group, —O—, —S—, or any combination thereof. Linking groups and the like.

  The general formula (DP-2) is preferably represented by the general formula (DP-2a).

一般式（ＤＰ−２ａ）において、Ｍ、Ａ_１、Ａ_２、Ｂ_１、Ｂ_２、環Ｚ_１、環Ｚ_２、Ｌ′、ｍ′及びｎ′は、一般式（ＤＰ−２ａ）におけるＭ、Ａ_１、Ａ_２、Ｂ_１、Ｂ_２、環Ｚ_１、環Ｚ_２、Ｌ′、ｍ′及びｎ′と同義である。
Ｌ″_１及びＬ″_２は、Ｃ−Ｒｂ_６又は窒素原子を表す。Ｒｂ_６は、水素原子又は置換基を表す。Ｌ″_１及びＬ″_２が、Ｃ−Ｒｂ_６の場合は、Ｒｂ_６同士が互いに結合し環を形成してもよい。

In the general formula (DP-2a), M, A ₁ , A ₂ , B ₁ , B ₂ , ring Z ₁ , ring Z ₂ , L ′, m ′ and n ′ are M in the general formula (DP-2a). , A ₁ , A ₂ , B ₁ , B ₂ , ring Z ₁ , ring Z ₂ , L ′, m ′ and n ′.
L ″ ₁ and L ″ ₂ represent C—Rb ₆ or a nitrogen atom. Rb ₆ represents a hydrogen atom or a substituent. When L ″ ₁ and L ″ ₂ are C—Rb ₆ , Rb ₆ may be bonded to each other to form a ring.

In the general formulas (DP), (DP-1), (DP-2), and (DP-2a), A ₂ is preferably a carbon atom, and A ₁ is preferably a carbon atom. More preferably, the ring Z ₁ is a substituted or unsubstituted benzene ring or pyridine ring, and more preferably a benzene ring.

<< Specific Example of Compound Having Structure Represented by General Formula (DP) >>
Specific examples of the compound having a structure represented by the above general formula (DP) of the present invention are shown below. The present invention is not limited to these.

<< Synthesis Example of Compound having Structure Represented by General Formula (DP) >>
Although the synthesis example of the compound which has a structure represented with the said general formula (DP) of this invention is demonstrated, this invention is not limited to this.
Hereinafter, although the synthesis example of the compound of this invention is demonstrated, this invention is not limited to this. A method for synthesizing D-102 in a specific example will be described as an example. Compounds of the present invention other than D-102 were synthesized in a similar manner.

（化合物Ｄ−１０２の合成）

(Synthesis of Compound D-102)

D-102Lig (3.90 g), iridium acetate (0.90 g) and 100 mL of ethylene glycol were placed in a 200 mL eggplant flask, and stirring was continued for 10 hours at 160 ° C. under a nitrogen stream. After completion of the reaction, the reaction mixture was cooled to room temperature, and the precipitate was separated by filtration. The collected solid was purified by silica gel chromatography to obtain 1.40 g of a yellow target product. An NMR spectrum chart and a thermal analysis chart are shown in FIGS.
For the NMR spectrum chart, an FT-NMR Lambda 400 (manufactured by JEOL Ltd.) apparatus was used, and the measurement conditions were magnetic field strength: 400 MHz, solvent: dichloromethane-d2, and measurement temperature: 25 ° C.
In addition, the thermal analysis chart uses a differential thermothermal gravimetric simultaneous measurement apparatus SII TG / DTA6200, and the measurement conditions are nitrogen gas flow, temperature increase rate: 10 ° C./min, measurement range: 30 ° C. to 500 ° C., sample mass : 3.23 mg. In the thermal analysis chart, the vertical axis indicates the weight reduction degree, and the horizontal axis indicates the temperature.

<< Other characteristics of the compound having the structure represented by the general formula (DP) >>
The compound having the structure represented by the above general formula (DP) is not limited to the organic EL element material, but has an antioxidant action, and is suitably used for organometallic complexes used as various organic electronics element materials.
The organometallic complex of the present invention also functions as an antioxidant and functions as an image stabilizer as one of its functions. For example, a dye used for image formation undergoes a fading process due to singlet oxygen. When the metal complex is arranged in the vicinity of the dye molecule, the action of quenching the singlet oxygen of the metal complex works, and as a result, the decomposition of the dye molecule can be suppressed.

[Organic electroluminescence device]
The organic electroluminescent device of the present invention is an organic electroluminescent device having one or a plurality of organic layers including a light emitting layer between at least one pair of an anode and a cathode, and any one of the organic layers is the organic It contains an electroluminescent element material.
Although various forms can be taken as embodiments of the present invention, it is preferable that the light emitting layer contains the material for an organic electroluminescence element from the viewpoint of manifesting the effects of the present invention.
In addition, the phosphorescent organic compound may contain the phosphorescent organic metal complex having the structure represented by the general formula (DP) as the organic electroluminescent element material. It is preferable from the viewpoint of the stability of the metal complex.
In addition, it is preferable that an Ir complex is contained as the phosphorescent organometallic complex contained in the light emitting layer because the effects of the present invention are more remarkably exhibited.
Furthermore, the organic layer is preferably formed by a wet process.

<< Constituent layer of organic electroluminescence element >>
In the organic EL device of the present invention, preferred specific examples of the layer structure of various organic layers sandwiched between the anode and the cathode are shown below, but the present invention is not limited thereto.

(I) Anode / light emitting layer unit / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer unit / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer unit / hole blocking Layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emission Layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode

Furthermore, the light emitting layer unit may have a non-light emitting intermediate layer between a plurality of light emitting layers, and may have a multi-photon unit configuration in which the intermediate layer is a charge generation layer. In this case, as the charge generation layer, ITO (indium tin oxide), IZO (indium zinc oxide), ZnO ₂ , TiN, ZrN, HfN, TiO _x , VO _x , CuI, InN, GaN, CuAlO _{2 are used.} , CuGaO ₂ , SrCu ₂ O ₂ , LaB ₆ , RuO _{2 and} other conductive inorganic compound layers, Au / Bi ₂ O _{3 and} other bilayer films, SnO ₂ / Ag / SnO ₂ , ZnO / Ag / ZnO, Bi ₂ O ₃ / Au / Bi ₂ O ₃ , TiO ₂ / TiN / TiO ₂ and multilayer films such as TiO ₂ / ZrN / TiO ₂ , fullerenes such as C ₆₀ , conductive organic layer such as oligothiophene, metal phthalocyanine And conductive organic compound layers such as metal-free phthalocyanines, metalloporphyrins and metal-free porphyrins.

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

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

<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 or the electron transport layer and 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 thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the stability of the emission color against the drive current and the uniformity of the film, preventing unnecessary application of high voltage during light emission. Preferably, it is adjusted to the range of 2 nm to 5 μm, more preferably adjusted to the range of 2 to 200 nm, and particularly preferably adjusted to the range of 5 to 100 nm.

  For the production of the light emitting layer, a light emitting dopant or a host compound described later is used, for example, a vacuum deposition method or a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll). Examples thereof include a coating method, an inkjet method, a printing method, a spray coating method, a curtain coating method, and an LB method (Langmuir Brodgett method). In addition, when using the hexadentate ortho metal iridium complex based on this invention as a material of a light emitting layer, it is preferable to form into a film by a wet process.

  In the light emitting layer of the organic EL device of the present invention, a light emitting dopant (a phosphorescent dopant (also referred to as a phosphorescent dopant or a phosphorescent dopant group) or a fluorescent dopant) compound and a light emitting host compound are contained. It is preferable to contain.

(1) Luminescent dopant As the luminescent dopant (also referred to as “luminescent dopant” or simply “dopant”), a fluorescent dopant (also referred to as a fluorescent compound), a phosphorescent dopant (phosphorescent material, phosphorescent compound) , Also referred to as a phosphorescent compound or the like).
The present invention is characterized in that an organometallic complex having a structure represented by the above general formula (DP) is used as the phosphorescent dopant. In the present invention, it is particularly preferable that the phosphorescent dopant is an iridium complex.
In the invention, various light-emitting dopants described in detail below can be used in combination.

(1.1) Phosphorescent dopant The phosphorescent dopant according to the present invention (also referred to as “phosphorescent dopant” or “phosphorescent dopant”) is a compound in which light emission from an excited triplet is observed, Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and is defined as a compound having a phosphorescence quantum yield of 0.01 or more at 25 ° C. 1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.

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

(1.2) Fluorescent dopants Fluorescent dopants (also referred to as “fluorescent compounds”) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, and fluorescein dyes. Examples include dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes, polythiophene dyes, rare earth complex phosphors, and compounds having high fluorescence quantum yields typified by laser dyes.

(1.3) Combined use with conventionally known dopants In addition, the luminescent dopant according to the present invention may be used in combination of a plurality of types of compounds, a combination of phosphorescent dopants having different structures, or a phosphorescent dopant. And a fluorescent dopant may be used in combination.

  Here, as a luminescent dopant, as a specific example of a conventionally known luminescent dopant that may be used in combination with a compound (organometallic complex) having a structure represented by the general formula (DP) according to the present invention, D- Although 1-D-47 is mentioned, this invention is not limited to these.

(2) Luminescent Host Compound In the present invention, the luminescent host compound (also referred to as “luminescent host”, “luminescent host”, or “host compound”) is a compound contained in the luminescent layer. Is defined as a compound having a phosphorescence quantum yield of phosphorescence emission of less than 0.1 at room temperature (25 ° C.). The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  There is no restriction | limiting in particular as a luminescent host which can be used for this invention, The compound conventionally used with an organic EL element can be used. Typically, carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds and other basic skeletons, carboline derivatives and diazacarbazole derivatives (where, Examples of the diazacarbazole derivative include those in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.

  Known light-emitting host compounds that can be used in the present invention include compounds that have a hole transporting ability or an electron transporting ability, prevent the emission of longer wavelengths, and have a high Tg (glass transition temperature). preferable.

  In the present invention, conventionally known luminescent host compounds may be used alone or in combination of two or more. By using a plurality of types of luminescent host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Further, by using a plurality of kinds of the organometallic complex of the present invention and / or a conventionally known compound used as the phosphorescent dopant, it becomes possible to mix different emission colors, thereby obtaining an arbitrary emission color. .

  The luminescent host compound used in the present invention may be a low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable luminescent host). ), Or one or more of such compounds may be used.

  Specific examples of known luminescent host compounds include the compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. , 2002-302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Hereinafter, although the specific example (OC-1 to OC-32) used as a luminescent host compound of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

  Furthermore, a compound represented by the following general formula (A) or general formula (B) is particularly preferable as the light-emitting host compound of the light-emitting layer of the organic EL device of the present invention.

  In the general formulas (A) and (B), Xa represents an oxygen atom or a sulfur atom. Xb, Xc, Xd and Xe each represent a hydrogen atom, a substituent or a group represented by the following general formula (C). At least one of Xb, Xc, Xd, and Xe represents a group represented by the following general formula (C), and at least one of the groups represented by the following general formula (C) represents Ar as a carbazolyl group. .

In general formula (C), L ₄ represents a divalent linking group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. n represents an integer of 0 to 3, and when n is 2 or more, the plurality of L ₄ may be the same or different. * Represents a linking site with the general formula (A) or (B). In the compound represented by the general formula (A), preferably at least two of Xb, Xc, Xd and Xe are represented by the general formula (C), and more preferably Xc is represented by the general formula (C). In addition, Ar in the general formula (C) represents a carbazolyl group represented by the following general formula (D).

In general formula (D), Xf represents N (R ″), an oxygen atom or a sulfur atom, E _{1 to} E ₈ represent C (R ″ ₁ ) or N, R ″ and R ″ ₁ are hydrogen atoms, It represents a substituent or a linking site with L ₄ in formula (C). * Represents a linking site with L ₄ in the general formula (C).

  Hereinafter, H-1 to H-56 are given as specific examples of the compound represented by the general formula (A) preferably used as a host compound (also referred to as a light emitting host) of the light emitting layer of the organic EL device of the present invention. However, the present invention is not limited to these.

  In addition, a compound represented by the following general formula (A ′) is also particularly preferably used as a light-emitting host of the light-emitting layer of the organic EL device of the present invention.

In the general formula (A ′), Xa represents an oxygen atom or a sulfur atom, and Xb and Xc each represents a substituent or a group represented by the general formula (C).
At least one of Xb and Xc represents a group represented by the general formula (C), and at least one of the groups represented by the general formula (C) represents Ar as a carbazolyl group.

In the compound represented by the general formula (A ′), Ar in the general formula (C) preferably represents a carbazolyl group which may have a substituent, and more preferably, in the general formula (C). Ar may have a substituent and represents a carbazolyl group linked to L ₄ in formula (C) at the N-position.

  The compound represented by the general formula (A ′) that is preferably used as a host compound (also referred to as a light-emitting host) of the light-emitting layer of the organic EL device of the present invention is specifically a specific example previously used as a light-emitting host. OC-9, OC-11, OC-12, OC-14, OC-18, OC-18, OC-29, OC-30, OC-31 and OC-32 mentioned as, but the present invention is not limited to these. Not.

《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 with a single layer or a plurality of layers.

  The electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer, and as a constituent material of the electron transport layer, any one of conventionally known compounds may be selected and used in combination. Is also possible.

Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include polycyclic aromatic hydrocarbons such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, At least one of the carbon atoms of the hydrocarbon ring constituting the carboline ring of the ring tetracarboxylic anhydride, carbodiimide, fluorenylidenemethane derivative, anthraquinodimethane and anthrone derivative, oxadiazole derivative, carboline derivative, carboline derivative is nitrogen Derivatives having a ring structure substituted with an atom, hexaazatriphenylene derivatives and the like.
Furthermore, in the oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material.
A polymer material in which these materials are introduced into a polymer chain, or a polymer material having these materials as a polymer main chain can also be used.

  In addition, organometallic complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these organometallic complexes are indium, magnesium Organometallic complexes replaced with copper, calcium, tin, gallium or lead can also be used as the electron transporting material.

In addition, metal-free or metal phthalocyanine, or those having a terminal substituted with an alkyl group or a sulfonic acid group can be used as the electron transport material.
In addition, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is formed of an electron transport material, for example, a vacuum deposition method or a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, a spray method). The film is preferably formed by thinning by a coating method, a curtain coating method, an LB method (such as Langmuir Brodgett method)).

  Although there is no restriction | limiting in particular about the layer thickness of an electron carrying layer, Usually, about 5-5000 nm, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  The electron transport layer may be doped with an n-type dopant such as an organometallic complex or a metal halide.

  Specific examples of known electron transport materials include compounds described in the following documents. For example, ET-1 to ET-39 described in [0096] to [0104] of JP2012-169325A and E1-1 to ET1 to [0082] of JP2012-104536A are disclosed. And compounds such as E5-6.

"cathode"
As the cathode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures and rare earth metals. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, A magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum or the like is preferred.

  The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the layer thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm.

In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.
In addition, a transparent or translucent cathode can be produced by producing a conductive transparent material mentioned in the explanation of the anode described later on the cathode after producing the metal with a layer thickness of 1 to 20 nm. By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

<< Injection layer: electron injection layer (cathode buffer 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, 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. You may let them.

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

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Representative phthalocyanine buffer layer, hexaazatriphenylene derivative buffer layer, oxide buffer layer typified by vanadium oxide, amorphous carbon as described in JP-T-2003-519432 and JP-A-2006-135145 Examples thereof include a buffer layer, a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) and polythiophene, and an orthometalated complex layer represented by tris (2-phenylpyridine) iridium complex.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by, alkali metal compound buffer layer typified by lithium fluoride and potassium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride and cesium fluoride, typified by aluminum oxide Examples thereof include an oxide buffer layer. The buffer layer (injection layer) is preferably a very thin film, and the layer 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.

  In a broad sense, the hole blocking layer has a function of an electron transport layer and is composed of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes, while transporting electrons. By blocking holes, the recombination probability of electrons and holes can be improved.

  Moreover, the structure of the electron carrying layer mentioned above 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 includes a carbazole derivative, a carboline derivative, a diazacarbazole derivative (herein, a diazacarbazole derivative refers to any one of the carbon atoms constituting the carboline ring). It is preferable to contain a compound that is replaced with a nitrogen atom.

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

The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied orbital) level of the compound to the vacuum level, and can be determined by the following method, for example.
(1) Wave motion using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), molecular orbital calculation software manufactured by Gaussian, USA. It can be obtained as a value (eV unit converted value) calculated by performing structure optimization using B3LYP / 6-31G * as a function keyword (calculation method and basis function). 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, in a broad sense, has a function of a hole transport layer, and is made of a material having a function of transporting holes while having a remarkably small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination 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 layer thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

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

The hole transport material has any of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, or conductive polymer oligomers, particularly thiophene oligomers.
Further, azatriphenylene derivatives such as those described in JP-T-2003-519432 and JP-A-2006-135145 can also be used as a hole transport material.

  Although the above-mentioned thing can be used as a positive hole transport material, It is preferable to use a porphyrin compound, an aromatic tertiary amine compound, and a styryl amine compound, especially 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-diphenylaminostilbene; N-phenylcarbazole, and also two fused aromatic rings described in US Pat. No. 5,061,569. What is contained in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), Japanese Patent Laid-Open No. 4-308688 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA), etc., in which three triphenylamine units described in 1 are linked in a starburst type Is mentioned.

Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.
In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

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

The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can.
Although there is no restriction | limiting in particular about the layer thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

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

"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, a thin film may be formed by vapor deposition or sputtering of these electrode materials, and a pattern of a desired shape may be formed by photolithography, or when pattern accuracy is not required (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 layer thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

《Support substrate》
The support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention is not particularly limited in the type of glass, plastic, etc., and is transparent. Or 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 (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, 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 polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, 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 1 × 10 ⁻² g / m ² · 24 h or less barrier film, and further measured by a method according to JIS K 7126-1987. A high barrier film having an oxygen permeability of 1 × 10 ⁻³ ml / m ² · 24 h · atm or less and a water vapor permeability of 1 × 10 ⁻⁵ g / m ² · 24 h or less is preferable.

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

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

  Examples of the opaque support substrate include a metal plate such as aluminum and stainless steel, a film, an opaque resin substrate, a ceramic substrate, and the like.

  The external extraction quantum efficiency at room temperature (25 ° C.) of light emission of the organic EL device of the present invention is preferably 1% or more, and more preferably 5% or more.

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

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

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

  Next, a thin film containing organic compounds such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and a cathode buffer layer, which are element materials, is formed thereon.

As a method for forming a thin film, for example, a thin film can be formed by a vacuum deposition method, a wet method (also referred to as a wet process), or the like.
Wet methods include spin coating, casting, die coating, blade coating, roll coating, ink jet, printing, spray coating, curtain coating, and LB, but precise thin films can be formed. In view of high productivity, a method having high roll-to-roll method suitability such as a die coating method, a roll coating method, an ink jet method or a spray coating method is preferable. Different film formation methods may be applied for each layer.

Examples of the liquid medium for dissolving or dispersing the organic EL device material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene and xylene. , Aromatic hydrocarbons such as mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, or organic solvents such as DMF (N, N'-dimethylformamide) and DMSO (Dimethyl sulfoxide) 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 the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a layer thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

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

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

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

  The sealing member may be disposed so as to cover the display area of the organic EL element, and may be a concave plate shape or a flat plate shape. 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 those formed from polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone, and the like.
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 or a metal film can be preferably used because the element can be thinned.
Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / m ² · 24 h · atm or less, and measured by a method according to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is preferably 1 × 10 ⁻³ g / m ² · 24 h or less.

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

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-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 with heat processing, what can be adhesively cured from room temperature (25 degreeC) 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, or silicon nitride may be used. it can.
Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

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

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide and magnesium iodide) and perchloric acids (eg perchloric acid) Barium and 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 device, 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 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 and metal plate / film as those used for the sealing can be used. 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 technique 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), condensing on the substrate. A method of improving the efficiency by imparting the property (Japanese Patent Laid-Open No. Sho 63-314795), a method of forming a reflective surface on the side surface of the element (Japanese Patent Laid-Open No. 1-220394), and between the substrate and the light emitter A method of introducing an antireflection film by introducing a flat layer having an intermediate refractive index (Japanese Patent Laid-Open No. 62-172691), and introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter. A method (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of the substrate, the transparent electrode layer and the light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951), and the like. is there.

  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 brightness or durability.

  When a medium with 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.

  Further, 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 reduced when the thickness of the low-refractive index medium is about the wavelength of light and the thickness of the electromagnetic wave 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, for example, so as to provide a microlens array-like structure, or in combination with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

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

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

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

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light sources. Examples of light sources include lighting devices (home lighting, interior lighting), clocks and backlights for liquid crystals, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, and light. Examples include a light source of a sensor. Although it does not limit to these, it can be effectively used especially for the use as a backlight of a liquid crystal display device and a light source for illumination.

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

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

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

<Display device>
The organic EL element of the present invention is suitably used for a display device. The display device may be single color or multicolor, but here, the multicolor display device will be described.

In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.
In the case of patterning only the light emitting layer, there is no limitation on the method, but a vapor deposition method, an inkjet method, a spin coating method, and a printing method are preferable.

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

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

  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. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

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

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

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

Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a display device composed of organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, a wiring unit C that electrically connects the display unit A and the control unit B, and the like.
The control unit B is electrically connected to the display unit A via the wiring unit C, and sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside. Sequentially emit light according to the image data signal, scan the image, and display the image information on the display unit A.

FIG. 2 is a schematic diagram of a display device using an active matrix method.
The display unit A includes a wiring unit C including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below.
FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

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

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

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

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

When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, since the capacitor 13 holds the charged potential of the image data signal even if the driving of the switching transistor 11 is turned off, the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.
That is, the organic EL element 10 emits light by the switching transistor 11 and the drive transistor 12 that are active elements for the organic EL element 10 of each of the plurality of pixels, and the light emission of the organic EL element 10 of each of the plurality of pixels 3. It is carried out. Such a light emitting method is called an active matrix method.

Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or by turning on / off a predetermined light emission amount by a binary image data signal. Good. The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.
In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

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

《Lighting device》
The organic EL element of the present invention is suitably used for a lighting device.
The organic EL element of the present invention may be used as an organic EL element having a resonator structure. Examples of the purpose of use of the organic EL element having such a resonator structure include a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processing machine, and a light source of an optical sensor. It is not limited. Moreover, you may use for the said use by making a laser oscillation.
Further, the organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a type for directly viewing a still image or a moving image. It may be used as a display device (display).
The driving method when used as a display device for reproducing a moving image may be either a passive matrix method or an active matrix method. Alternatively, it is possible to produce a full-color display device by using two or more organic EL elements of the present invention having different emission colors.

Moreover, the organic EL element material of the present invention can be applied to an organic EL element that emits substantially white light as a lighting device. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials and mixed to obtain white light emission. The combination of a plurality of emission colors may include three emission maximum wavelengths of three primary colors of red, green, and blue, or two of the complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.
In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. Any of those in combination with a dye material that emits light as a light source, but in the white organic EL device according to the present invention, it is only necessary to combine and mix a plurality of light-emitting dopants.

In addition, the organic EL element material forming method of the present invention may be simply arranged by providing a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, or the like, and separately coating with the mask. Since the other layers are common, patterning of a mask or the like is unnecessary, and for example, an electrode film can be formed on one surface by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, or the like, and productivity is improved.
According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.
There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display element, the organometallic complex which concerns on this invention so that it may adapt to the wavelength range corresponding to CF (color filter) characteristic, or Any one of known luminescent materials may be selected and combined to whiten.

<< One aspect of lighting device >>
One mode of a lighting device including the organic EL element of the present invention will be described.
The non-light emitting surface of the organic EL device of the present invention is covered with a glass case, a 300 μm thick glass substrate is used as a sealing substrate, and an epoxy photocurable adhesive (LUX Track LC0629B) was applied. This is stacked on the cathode and brought into close contact with the transparent support substrate, UV light is irradiated from the glass substrate side, cured, and sealed to form an illumination device as shown in FIGS. Can do.

  FIG. 5 shows a schematic diagram of the illumination device. The organic EL element 101 of the present invention is covered with a glass cover 102 (note that the sealing operation with the glass cover is a glove box under a nitrogen atmosphere (purity 99.75%) without bringing the organic EL element 101 into contact with the atmosphere. In an atmosphere of high-purity nitrogen gas of 999% or more).

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

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

[Example 1]
<< Production of Organic EL Element 1-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

  A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by HC Starck Co., Ltd., CLEVIO P VP AI 4083) to 70% with pure water on the transparent support substrate. After forming a thin film by spin coating at 3000 rpm for 30 seconds, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a layer thickness of 20 nm.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD is placed in a molybdenum resistance heating boat as a hole transport material, and OC- 200 mg of 30 was put, 200 mg of ET-1 as an electron transport material was put in another resistance heating boat made of molybdenum, and 100 mg of Comparative 1 was put as a dopant in another resistance heating boat made of molybdenum, and attached to a vacuum deposition apparatus.

Next, the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, and the heating boat containing α-NPD was energized and heated, evaporated on the transparent support substrate at a deposition rate of 0.1 nm / second, and a layer thickness of 20 nm. The second hole transport layer was provided.

  Further, the heating boat containing OC-30 as a host compound and Comparative 1 as a dopant was energized and heated, and deposited on the second hole transport layer at a deposition rate of 0.1 nm / second and 0.006 nm / second, respectively. A light emitting layer having a layer thickness of 40 nm was provided by co-evaporation.

Furthermore, it supplied with electricity to the said heating boat containing ET-1, and heated, and it vapor-deposited on the said light emitting layer with the vapor deposition rate of 0.1 nm / sec, and provided the electron carrying layer with a layer thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature (25 degreeC).

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a layer thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-105 >>
In preparation of the organic EL element 1-1, the dopant in the light emitting layer was changed to the compounds described in Table 1-1 to Table 1-3.
Other than that produced the organic EL elements 1-2 to 1-105 in the same manner.

<< Evaluation of Organic EL Elements 1-1 to 1-105 >>
When evaluating the obtained organic EL elements 1-1 to 1-105, 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. In addition, an epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and a lighting device as shown in FIGS. 5 and 6 was produced and evaluated.
The following evaluation was performed for each sample thus prepared. The evaluation results are shown in Table 1-1 to Table 1-3.

(1) External extraction quantum efficiency (also simply referred to as efficiency)
The organic EL device is turned on at room temperature (25 ° C.) under a constant current condition of ^2.5 mA / cm ² and the emission luminance (L) [cd / m ² ] immediately after the start of lighting is measured. Efficiency (η) was calculated.
Here, the measurement of emission luminance was performed using CS-1000 (manufactured by Konica Minol), and the external extraction quantum efficiency was expressed as a relative value where the organic EL element 1-1 was 100.

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

(3) Voltage rise at the time of driving The voltage when the organic EL element was driven at room temperature (25 ° C.) and a constant current condition of ^2.5 mA / cm ² was measured, respectively, and the measurement result was calculated by the calculation formula shown below. Calculated.
It represents with the relative value which sets the organic EL element 1-1 to 100.
Voltage rise at the time of driving (relative value) = drive voltage at half brightness-initial drive voltage Note that a smaller value indicates a smaller voltage rise at the time of driving for comparison.

(4) Calculation of relative positions of substituents capable of forming intramolecular hydrogen bonds The relative positions of substituents capable of forming intramolecular hydrogen bonds in metal complexes (dopants) in Table 1-1 to Table 1-3 are molecular orbitals. Calculation was performed using calculation software (gaussian 09 manufactured by Gaussian, USA) (Revision C.01, MJ Frisch, et al, Gaussian, Inc., 2010.).
When the intramolecular hydrogen bond is possible at a relative position of 500 pm or less, “◎” is indicated, and when there is no substituent capable of intramolecular hydrogen bond within the relative position of 500 pm, “−” is indicated.

  As is clear from the results shown in Table 1-1 to Table 1-3, the organic EL elements 1-3 to 1-105 of the present invention are compared to the organic EL elements 1-1 and 1-2 of the comparative example. It can be seen that the device characteristics are improved, such as high luminous efficiency and long life, and suppression of voltage rise during driving. It can also be seen that intramolecular hydrogen bonding is possible at a relative position of 500 pm or less.

[Example 2]

<< Preparation of White Light-Emitting Organic EL Element 2-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD is placed in a molybdenum resistance heating boat as a hole transport material, and OC- 200 mg of ET-2 as an electron transport material in another molybdenum resistance heating boat, 100 mg of Comparative 1 as a dopant in another molybdenum resistance heating boat, and as a dopant in another molybdenum resistance heating boat as a dopant 100 mg of D-10 was put and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, each of the heating boats containing α-NPD was separately energized, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. A first hole transport layer was provided.

  Further, when the heating boat containing OC-11 as the host compound, Comparative 1 as the blue dopant and D-10 as the red dopant was energized, the deposition rate of OC-11, Comparative 1 and D-10 was 100: 5. Was adjusted to 0.6, and the light emitting layer was provided by vapor deposition so as to have a layer thickness of 30 nm.

Furthermore, the heating boat containing ET-2 was energized and heated, and deposited on the light-emitting layer at a deposition rate of 0.1 nm / second to provide an electron transport layer having a layer thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature (25 degreeC).

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a layer thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 2-1 was produced.

  When the produced organic EL element 2-1 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 with the other compound of illustration.

<< Production of Organic EL Elements 2-2 to 2-69 >>
In preparation of the organic EL element 2-1, the blue dopant in the light emitting layer was changed to the compounds shown in Table 2-1 and Table 2-2.
Other than that produced the organic EL element 2-2 to 2-69 similarly.

<< Evaluation of Organic EL Elements 2-1 to 2-69 >>
When evaluating the obtained organic EL elements 2-1 to 2-69, the organic EL element was sealed in the same manner as the organic EL element 1-1 of Example 1, and as shown in FIGS. A lighting device was fabricated and evaluated.
Each sample thus produced was evaluated for external extraction quantum efficiency, half life, and voltage increase during driving in the same manner as in Example 1. The evaluation results are shown in Table 2-1 and Table 2-2. In addition, the measurement result of the external extraction quantum efficiency in Table 2-1 and Table 2-2, the light emission lifetime, and the voltage rise at the time of a drive was represented by the relative value which sets the measured value of the organic EL element 2-1 to 100.

  As is clear from the results shown in Tables 2-1 and 2-2, the organic EL elements 2-3 to 2-69 of the present invention are compared to the organic EL elements 2-1 and 2-2 of the comparative example. It can be seen that the device characteristics are improved, such as high luminous efficiency and long life, and suppression of voltage rise during driving.

[Example 3]
<< Production of Organic EL Element 3-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanState Co., Ltd.) on which a 100 nm ITO (indium tin oxide) film was formed as an anode on a 100 mm × 100 mm × 1.1 mm glass substrate. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

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

  On the first hole transport layer, a hole transport material Poly (N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl)) benzidine (manufactured by American Dye Source, ADS- A thin film was formed by spin coating using the chlorobenzene solution of No. 254). Heat drying at 150 ° C. for 1 hour to provide a second hole transport layer having a layer thickness of 40 nm.

  On this 2nd hole transport layer, using OC-11 as a host compound and the butyl acetate solution of the comparison 1 as a dopant, a thin film is formed with a spin coat method, and it heat-drys at 120 degreeC for 1 hour, layer thickness A 30 nm light emitting layer was provided.

  On this light emitting layer, a 1-butanol solution of ET-2 as an electron transport material was used, a thin film was formed by a spin coating method, and an electron transport layer having a layer thickness of 20 nm was provided.

This substrate was attached to a vacuum deposition apparatus, and the vacuum chamber was decompressed to 4 × 10 ⁻⁴ Pa. Subsequently, lithium fluoride was vapor-deposited to form an electron injection layer having a layer thickness of 1.0 nm, and aluminum was vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 3-1 was produced.

<< Production of Organic EL Elements 3-2 to 3-105 >>
In preparation of the organic EL element 3-1, the dopant in the light emitting layer was changed to the compounds shown in Tables 3-1 to 3-3.
Other than that produced the organic EL elements 3-2 to 3-105 in the same manner.

<< Evaluation of Organic EL Elements 3-1 to 3-105 >>
When evaluating the obtained organic EL elements 3-1 to 3-105, the organic EL element was sealed in the same manner as the organic EL element 1-1 of Example 1, and as shown in FIGS. A lighting device was fabricated and evaluated.
Each sample thus produced was evaluated for external extraction quantum efficiency, half life, and voltage increase during driving in the same manner as in Example 1. The evaluation results are shown in Tables 3-1 to 3-3. In addition, the measurement result of the external extraction quantum efficiency in Table 3-1 to Table 3-3, a half life, and the voltage rise at the time of a drive was represented by the relative value which sets the measured value of the organic EL element 3-1 to 100.

  As is apparent from the results shown in Tables 3-1 to 3-3, the organic EL elements 3-3 to 3-105 of the present invention are compared to the organic EL elements 3-1 and 3-2 of the comparative example. It can be seen that the device characteristics are improved, such as high luminous efficiency and long life, and suppression of voltage rise during driving.

[Example 4]
<< Production of Organic EL Elements 4-1 to 4-37 >>
In the production of the organic EL device 1-1 described in Example 1, the dopant in the light emitting layer was changed to the compounds described in Table 4.
Other than that produced the organic EL elements 4-1 to 4-37 in the same manner.

<< Evaluation of Organic EL Elements 4-1 to 4-37 >>
When evaluating the obtained organic EL elements 4-1 to 4-37, the organic EL element was sealed in the same manner as the organic EL element 1-1 of Example 1, and as shown in FIGS. A lighting device was fabricated and evaluated.
The following evaluation was performed for each sample thus prepared. The evaluation results are shown in Table 4.
(1) Thermal stability evaluation About the organic EL elements 4-1 to 4-37, the same vapor deposition boat (molybdenum resistance heating boat) was used, and five elements having the same configuration were produced (for example, the organic EL element 4- 1,4-1b, 4-1c, 4-1d, 4-1e).
Each of the first fabricated elements (for example, the organic EL element 4-1), the third fabricated element (for example, the organic EL element 4-1c), and the fifth fabricated element (for example, the organic EL element 4-1e). ) Was measured for the half-life by the same method as above. The half-life of each element was expressed as a relative value with the organic EL element 4-1 produced for the first time as 100.

  As is clear from the results shown in Table 4, the organic EL elements 4-1 and 4-2 of the comparative example are the element manufactured for the first time, the element manufactured for the third time, the element manufactured for the fifth time, In contrast, the organic EL elements 4-3 to 4-37 of the present invention are reduced to the first element, the third element, and the fifth element. It can be seen that the manufactured element and the half-life are hardly lowered, and the dopant used in the organic EL element of the present invention is excellent in thermal stability.

[Example 5]
<< Production of Organic EL Element 5-1 >>
An organic EL device 5-1 was produced using the same compound and the same method as the organic EL device 1-1 described in Example 1.

<< Production of Organic EL Elements 5-2 to 5-8 >>
In the production of the organic EL element 5-1, the electron transport material ET-1 was changed to the compounds shown in Table 5, and the others were produced in the same manner to produce organic EL elements 5-2 to 5-8, respectively.

<< Evaluation of Organic EL Elements 5-1 to 5-8 >>
When evaluating the obtained organic EL elements 5-1 to 5-8, the organic EL element was sealed in the same manner as the organic EL element 1-1 of Example 1, and as shown in FIGS. A lighting device was fabricated and evaluated.
The following evaluation was performed for each sample thus prepared. The evaluation results are shown in Table 5.

(1) Black spot The organic EL element that was continuously lit until the brightness reached half of the initial brightness was photographed with a microscope (MS-804, lens MP-ZE25-200 manufactured by Moritex Corporation). The photographed image was observed visually to check the situation of black spots (dark spots). The light emitting surface was divided into 100, and the black spot generation ratio was calculated from the number of black spots generated and evaluated according to the following criteria.
A: Black spot generation rate 0% (no black spots are generated)
○: Black spot generation rate 1% or more and less than 5% △: Black spot generation rate 5% or more and less than 10% ×: Black spot generation rate 10% or more

  As is clear from the results shown in Table 5, it can be seen that the organic EL element produced using the organometallic complex according to the present invention has suppressed generation of black spots as compared with the organic EL element of the comparative example.

[Example 6]
<Preparation of ink composition>
Dye material C-1 (pigment described in JP-A-10-264541) 1.2 g, polyvinyl acetal resin (KY-24: manufactured by Denki Kagaku Kogyo) 2.3 g, silicon-knitted urethane resin (SP-2105: Dainichi Seika) (Product) 1.8 g was dissolved in a mixed solution of 53 g of methyl ethyl ketone and 22 g of toluene to prepare an ink composition.

<< Preparation of Evaluation Sheet 6-1 >>
The above ink composition is coated and dried on a polyethylene terephthalate (PET) base having a thickness of 6 μm using a wire bar so that the coating amount after drying is 2.0 g / m ^2. A dye image evaluation sheet 6-1 having a containing layer was prepared. The evaluation sheet was dried for 15 minutes in an oven at 70 ° C. after being temporarily dried with a dryer.

<< Production of Evaluation Sheets 6-2 to 6-115 >>
Evaluation sheets 6-2 to 6-115 were prepared in the same manner except that 0.2 g of the metal complex shown in Table 6-1 to Table 6-3 was added to the ink composition used in the preparation of evaluation sheet 6-1. Produced.

  The following evaluation was performed on each evaluation sheet thus prepared. The evaluation results are shown in Tables 6-1 to 6-3.

(1) Evaluation of dye image for evaluation The maximum reflection density of an image was measured using X-rite 310TR. The dye image was irradiated with a xenon fade meter for 72 hours, and the dye residual ratio (%) obtained by (D1 / D0) × 100 was evaluated with D0 as the density before light irradiation and D1 after the light irradiation as D1.

  As is apparent from the results shown in Tables 6-1 to 6-3, the evaluation sheets 6-3 to 6-115 of the present invention are dyes respectively compared to the evaluation sheets 6-1 and 6-2 of the comparative example. It can be seen that the survival rate is improved.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate 108 with a transparent electrode Nitrogen gas 109 Water capturing Agent A Display unit B Control unit C Wiring unit

Claims (10)

A material for an organic electroluminescence device containing a neutral organometallic complex,
The organometallic complex has at least two ligands having a substituent capable of intramolecular hydrogen bonding, and
One substituent capable of hydrogen bonding in the molecule of the ligand is substituted at a position where a hydrogen bond can be formed with a substituent capable of hydrogen bonding in the molecule of another ligand constituting the same metal complex molecule. A material for an organic electroluminescence device, characterized by comprising:   The organic electroluminescent element material according to claim 1, wherein the number of ligands constituting the organometallic complex is at least three.   3. The organic electroluminescent element material according to claim 1, wherein three ligands constituting the organometallic complex form an intramolecular hydrogen bond. 4.   The atom on the ligand to which the intramolecular hydrogen bondable substituent is bonded is adjacent to the atom on the ligand covalently bonded to the central metal of the organometallic complex. The organic electroluminescent element material according to any one of claims 1 to 3. An organic electroluminescent device having one or more organic layers including a light emitting layer between at least one pair of an anode and a cathode,
Either of the said organic layers contains the organic electroluminescent element material as described in any one of Claim 1- Claim 4. The organic electroluminescent element characterized by the above-mentioned.   6. The organic electroluminescent element according to claim 5, wherein the light emitting layer contains the material for an organic electroluminescent element. The said light emitting layer contains the phosphorescence-emitting organometallic complex which has a structure represented by the following general formula (DP) as said organic electroluminescent element material. 6. The organic electroluminescence device according to 6.

[Wherein M represents Ir, Pt, Rh, Ru, Ag, Cu or Os. A ₁ , A ₂ , B ₁ , and B ₂ each represent a carbon atom or a nitrogen atom. Ring Z ₁ represents a 6-membered aromatic hydrocarbon ring or 5-membered or 6-membered aromatic heterocycle formed together with A ₁ and A ₂ . Ring Z ₂ represents a 5-membered or 6-membered aromatic heterocycle formed together with B ₁ and B ₂ . Ring Z ₁ and ring Z ₂ may have a substituent, and the substituents may be bonded to each other to form a condensed ring structure. Moreover, the substituent of each ligand may mutually couple | bond together and the ligands may connect. L ′ represents a monoanionic bidentate ligand coordinated to M. m ′ represents an integer of 0 to 2. n ′ represents an integer of 1 to 3. m ′ + n ′ is 2 or 3. When m ′ and n ′ are 2 or more, the ligands represented by ring Z ₁ and ring Z ₂ and L ′ may be the same or different. ]   The organic electroluminescent element according to any one of claims 5 to 7, wherein an Ir complex is contained as the phosphorescent organic metal complex contained in the light emitting layer.   The organic electroluminescence device according to any one of claims 5 to 8, wherein the organic layer is formed by a wet process. An organometallic complex having the same structure as the organometallic complex contained in the material for an organic electroluminescence element according to any one of claims 1 to 4,
Having at least two ligands having substituents capable of intramolecular hydrogen bonding; and
One substituent capable of hydrogen bonding in the molecule of the ligand is substituted at a position where a hydrogen bond can be formed with a substituent capable of hydrogen bonding in the molecule of another ligand constituting the same metal complex molecule. An organometallic complex characterized in that

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