JP2012079533A - Manufacturing method of organic electroluminescent element and organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element with high light extraction efficiency.SOLUTION: In this manufacturing method, a luminescent layer which has a luminescent material of an aspect ratio of 3 or larger and a host material capable of developing liquid crystal property is applied for deposition in the temperature range in which the host material develops the liquid crystal property.

Description

  The present invention relates to a method for manufacturing an organic electroluminescent element and an organic electroluminescent element.

As a device using organic materials, organic electroluminescent elements (hereinafter also referred to as organic EL elements) are expected to develop as lighting applications as solid light emitting large-area full-color display elements and inexpensive large-area surface light sources. ing. In general, an organic electroluminescent element is composed of an organic layer including a light emitting layer and a pair of counter electrodes sandwiching the organic layer. When a voltage is applied to such an organic electroluminescence device, electrons are injected from the cathode and holes are injected from the anode into the organic layer. The electrons and holes recombine in the light emitting layer, and light is emitted by releasing energy as light when the energy level returns from the conduction band to the valence band.
In a normal organic EL element, since the direction of the transition dipole moment of the light emitting material is random, the light is emitted isotropically as a whole.

In general, an organic EL element has a refractive index higher than that of each layer including the light emitting layer and a substrate of the element (glass substrate). For example, in an organic electroluminescent element, an organic layer such as a light emitting layer has a refractive index of 1.6-2.1. For this reason, when the transition dipole moment of the light emitting material emits isotropically in a random orientation as a whole, most of the emitted light is totally reflected at the interface, so about 20 of the light emitted from the light emitting layer. % Can be taken out of the device. In order to obtain high luminance in this state, it is necessary to emit light excessively. As a result, there is a problem that the durability of the element is lowered.
On the other hand, by horizontally aligning the transition dipole moment of the luminescent material on the substrate, anisotropic emission that increases the luminescent component in the direction perpendicular to the substrate surface can be obtained, so total reflection at the interface can be suppressed, It is known that the light extraction efficiency is improved in principle.

Such a horizontal alignment element can be manufactured by applying a liquid crystalline host material and controlling the direction of the transition dipole moment of the light emitting material.
For example, Patent Document 1 uses a light-emitting discotic liquid crystal layer as a light-emitting layer for the purpose of obtaining an organic EL element having high light extraction efficiency, excellent durability, and excellent light beam directivity. It is described.
Patent Document 2 discloses light emission in which a phosphorescent compound having a planar molecular skeleton is mixed with a liquid crystal compound exhibiting a discotic phase or a smectic phase to form a light emitting layer by vapor deposition for the purpose of improving light extraction efficiency. An element is described.

JP-A-10-321371 JP 2002-43056 A

An organic EL element can be produced by forming a light emitting layer and other organic layers by a dry method such as vapor deposition or a wet method such as coating. However, a wet method is attracting attention from the viewpoint of productivity. Yes. For example, in Patent Document 1, a light emitting layer is formed by spin coating a discotic liquid crystal composition.
However, in the film formation by coating, the orientation of the liquid crystalline material may be deteriorated due to coating unevenness. In spin coating or the like, coating is usually performed at room temperature in order to suppress unevenness due to solvent volatilization, but the orientation of the liquid crystal material is low at room temperature. For this reason, the orientation of the liquid crystalline material is improved by heating after coating, but it may be crystallized by heating. Therefore, in the film formation by coating, it is required to improve the decrease in light extraction efficiency due to the decrease in orientation and crystallization.

  An object of the present invention is to provide an organic electroluminescent device having high light extraction efficiency.

  In view of the above situation, the present inventors have conducted intensive research and found that when applying a liquid crystalline host material, the temperature of the material exhibits liquid crystallinity, thereby achieving a uniform and highly oriented light emitting layer. It was also found that the material can be prevented from being crystallized unexpectedly.

（一般式（１）中、Ｘ，Ｙ，Ｚは、炭素原子又は窒素原子を表し、ＺとＹのいずれか一方が窒素原子である。Ｙが窒素原子のときは、Ｘは炭素原子である。ｍ、ｎ、ｐ、ｑは、それぞれ独立に０〜３の整数を表す。Ａｒはアリール基を表す。Ｒ_１〜Ｒ_４は、それぞれ独立に、アルキル基、アリール基、アルコキシ基、アリールオキシ基、フッ素原子、シアノ基、シリル基、又はヘテロ環基を表し、ｍ、ｎ、ｐ、ｑが２以上の場合、複数のＲ_１〜Ｒ_４は各々隣同士で互いに連結して環状構造を形成してもよい。）
一般式（２）

（一般式（２）中、Ｘ，Ｙ，Ｚは、炭素原子又は窒素原子を表し、ＺとＹのいずれか一方が窒素原子である。Ｙが窒素原子のときは、Ｘは炭素原子である。ｒ、ｓ、ｔ、ｕは、それぞれ独立に０〜３の整数を表す。Ｒ_５〜Ｒ_８は、それぞれ独立に、アルキル基、アリール基、アルコキシ基、アリールオキシ基、フッ素原子、シアノ基、シリル基、又はヘテロ環基を表し、ｒ、ｓ、ｔ、ｕが２以上の場合、複数のＲ_５〜Ｒ_８は各々隣同士で互いに連結して環状構造を形成してもよい。Ｗ_１とＷ_２とは、アルキル基を表し、互いに結合して環状構造を形成してもよい。）
一般式（３）

（一般式（３）中、Ｒ_９〜Ｒ_１６は、それぞれ独立に、水素原子、アルキル基、アリール基、シリル基、又はヘテロ環基を表し、Ｒ_９とＲ_１１、Ｒ_１１とＲ_１２、Ｒ_１２とＲ_１０、Ｒ_１４とＲ_１５、Ｒ_１３とＲ_１６は、互いに結合して環状構造を形成してもよい。）
一般式（４）

（一般式（４）中、Ｘ，Ｙ，Ｚは、炭素原子又は窒素原子を表し、ＺとＹのいずれか一方が窒素原子である。Ｙが窒素原子のときは、Ｘは炭素原子である。ｍ、ｎ、ｐ、ｇは、それぞれ独立に０〜３の整数を表す。Ａｒはアリール基を表す。Ｒ_１〜Ｒ_３及びＲ_３０、それぞれ独立に、アルキル基、アリール基、アルコキシ基、アリールオキシ基、フッ素原子、シアノ基、シリル基、又はヘテロ環基を表し、ｍ、ｎ、ｐ、ｇが２以上の場合、複数のＲ_１〜Ｒ_３及びＲ_３０は各々隣同士で互いに連結して環状構造を形成してもよい。Ｍ、Ｑとしては、それぞれ独立に炭素原子又は窒素原子である。）
一般式（５）

（一般式（５）中、Ｚは、炭素原子又は窒素原子を表す。ｍ、ｎ、ｇはそれぞれ独立に０〜３の整数を表す。Ａｒはアリール基を表す。Ｒ_１、Ｒ_２及びＲ_３０は、それぞれ独立に、アルキル基、アリール基、アルコキシ基、アリールオキシ基、フッ素原子、シアノ基、シリル基、又はヘテロ環基を表し、ｍ、ｎ、ｇが２以上の場合、複数のＲ_１、Ｒ_２及びＲ_３０は各々隣同士で互いに連結して環状構造を形成してもよい。Ｍ、Ｑとしては、それぞれ独立に炭素原子又は窒素原子である。）
［９］
前記有機電界発光素子が陽極と陰極との間に前記発光層を有する有機電界発光素子であって、前記燐光発光材料の遷移双極子モーメントが前記陽極に対して水平に配向されている、［６］〜［８］のいずれか１項に記載の有機電界発光素子の作製方法。
［１０］
前記発光層がフッ素原子含有化合物を０．０００１質量％〜１０質量％含有する、［１］〜［９］のいずれか１項に記載の有機電界発光素子の作製方法。
［１１］
［１］〜［１０］のいずれか１項に記載の作製方法により作製された有機電界発光素子。 That is, the means for solving the problems are as follows.
[1]
A method for producing an organic electroluminescent device having a light emitting layer including a light emitting material having an aspect ratio of 3 or more and a host material capable of exhibiting liquid crystallinity,
A method for manufacturing an organic electroluminescent element, wherein the light emitting layer is applied and formed in a temperature range in which the host material exhibits liquid crystallinity.
[2]
[1] The temperature range when the light emitting layer is coated and formed is a temperature higher than 40 ° C. and a temperature lower by 5 ° C. or more than the phase transition temperature from the liquid crystal phase to the isotropic phase of the host material. A method for producing an organic electroluminescent element.
[3]
The method for producing an organic electroluminescent element according to [1] or [2], wherein the host material has an aspect ratio of 3 or more.
[4]
The method for producing an organic electroluminescent element according to any one of [1] to [3], wherein the host material is a discotic liquid crystalline material.
[5]
The method for producing an organic electroluminescent element according to [4], wherein the discotic liquid crystalline material exhibits a discotic nematic liquid crystal phase.
[6]
The method for producing an organic electroluminescent element according to any one of [1] to [5], wherein the light emitting material is a phosphorescent light emitting material.
[7]
The method for producing an organic electroluminescent element according to [6], wherein the phosphorescent material is a platinum complex.
[8]
The method for producing an organic electroluminescent element according to [6] or [7], wherein the phosphorescent material is at least one selected from phosphorescent compounds represented by the following general formulas (1) to (5): .
General formula (1)

(In the general formula (1), X, Y, and Z represent a carbon atom or a nitrogen atom, and one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. M, n, p and q each independently represents an integer of 0 to 3. Ar represents an aryl group, and R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group or an aryloxy group. Group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and q are 2 or more, a plurality of R _{1 to} R ₄ are connected to each other to form a cyclic structure. It may be formed.)
General formula (2)

(In General Formula (2), X, Y, and Z represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. R, s, t and u each independently represents an integer of 0 to 3. R _{5 to} R ₈ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group. , A silyl group, or a heterocyclic group, and when r, s, t, and u are 2 or more, a plurality of R _{5 to} R ₈ may be connected to each other to form a cyclic structure. ₁ and W ₂ represent an alkyl group and may be bonded to each other to form a cyclic structure.
General formula (3)

(In General Formula (3), R _{9 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ may combine with each other to form a cyclic structure.)
General formula (4)

(In General Formula (4), X, Y, and Z represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. M, n, p and g each independently represents an integer of 0 to _3. Ar represents an aryl group, R _{1 to} R ₃ and R ₃₀ , each independently an alkyl group, an aryl group, an alkoxy group, An aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and g are 2 or more, a plurality of R _{1 to} R ₃ and R ₃₀ are connected to each other adjacent to each other. A cyclic structure may be formed, and M and Q are each independently a carbon atom or a nitrogen atom.)
General formula (5)

(In General Formula (5), Z represents a carbon atom or a nitrogen atom. M, n, and g each independently represents an integer of 0 to _3. Ar represents an aryl group. R ₁ , R _2, and R ₃₀ independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, or g is 2 or more, a plurality of R ₁ , R ₂ and R ₃₀ may be linked to each other to form a cyclic structure, and M and Q are each independently a carbon atom or a nitrogen atom.)
[9]
The organic electroluminescent device is an organic electroluminescent device having the light emitting layer between an anode and a cathode, and a transition dipole moment of the phosphorescent material is oriented horizontally with respect to the anode [6 ] The manufacturing method of the organic electroluminescent element of any one of [8].
[10]
The method for producing an organic electroluminescent element according to any one of [1] to [9], wherein the light emitting layer contains 0.0001% by mass to 10% by mass of a fluorine atom-containing compound.
[11]
[1] An organic electroluminescent device produced by the production method according to any one of [10].

  ADVANTAGE OF THE INVENTION According to this invention, an organic electroluminescent element with high light extraction efficiency can be provided.

It is the schematic which shows an example of the layer structure of the organic electroluminescent element which concerns on this invention.

  Hereinafter, the present invention will be described in detail. In the present specification, “to” indicates a range including the numerical values described before and after the minimum and maximum values, respectively.

[Method for Fabricating Organic Electroluminescent Device]
The method for producing an organic electroluminescent device of the present invention is a method for producing an organic electroluminescent device having a light emitting layer containing a light emitting material having an aspect ratio of 3 or more and a host material capable of exhibiting liquid crystallinity. The light emitting layer is applied and formed in a temperature range where the liquid crystallinity is exhibited.
By applying the host material at a temperature at which liquid crystallinity is exhibited, the host material can be aligned without being crystallized, and light extraction efficiency can be improved.

  From the viewpoint of improving the orientation of the host material and suppressing crystallization, the temperature range for coating the light emitting layer is higher than 40 ° C. and the phase transition temperature from the liquid crystal phase to the isotropic phase of the host material. Is preferably 5 ° C. or lower. More preferably, the temperature is higher than 45 ° C. and lower than the phase transition temperature from the liquid crystal phase to the isotropic phase of the host material by 10 ° C. or more. For example, the temperature range when the light emitting layer is applied and formed is preferably 40 ° C. to 120 ° C., more preferably 60 ° C. to 100 ° C.

The light-emitting layer can be formed by coating a substrate with a host material and, if necessary, a coating solution in which other materials are dissolved or dispersed in a solvent. In this case, the temperature at the time of application | coating film-forming can be adjusted by making the substrate temperature at the time of application | coating into the said temperature range. The means for heating the substrate is not particularly limited, and a known heating means can be used.
Examples of the method for applying the coating liquid include spin coating, casting, micro gravure coating, bar coating, roll coating, wire bar coating, dip coating, slit coating, capillary coating, and spray coating. Method, nozzle coating method, ink jet method and the like.

Hereinafter, materials that can be used for the coating liquid for forming the light emitting layer will be described.
(Host material)
The host material used in the present invention is a host material capable of exhibiting liquid crystallinity (hereinafter referred to as liquid crystal host material). By producing the light emitting layer by the method of the present invention, the liquid crystalline host material is oriented, whereby the orientation of the transition dipole moment of the light emitting material can be improved, and the light extraction rate is improved.
From the viewpoint of orientation, the liquid crystalline host material is preferably a highly planar material, preferably has an aspect ratio of 2.5 or more, more preferably 2.5 to 30, and even more preferably 3 to 20. .
The aspect ratio is a ratio (molecular diameter / molecular thickness) between the molecular diameter and the molecular thickness of the liquid crystalline host material.
Here, the molecular diameter means the longest molecular length, and is defined as follows by theoretical calculation. The theoretical calculation here is performed using a density functional method. Specifically, using Gaussian 03 (US Gaussian), basis function: 6-31G ^* , exchange correlation functional: B3LYP / LANL2DZ, Perform structural optimization calculations. Using the optimized structure obtained by the structure optimization calculation, the length of the longest molecular length in the ball and stick display is defined as the molecular diameter of the liquid crystalline host material.
In addition, the molecular thickness is assumed to be the above-mentioned molecular diameter as the x-axis, the y-axis is taken so that the molecular length in the y-axis direction becomes the maximum in this state, and the direction perpendicular to the x and y axes is taken as the z-axis. Means the thickness of the molecule in the z-axis direction. The molecular thickness is also obtained by the same method as the molecular diameter, and the length in the thickness direction of the molecule in the ball and stick display is defined as the molecular thickness.

  As the liquid crystal host material having high flatness, a discotic liquid crystal material (disk-like liquid crystal material) is preferable.

(Discotic liquid crystalline material)
The discotic liquid crystalline material is a liquid crystalline material composed of discotic molecules with high planarity, and has a refractive index of negative optical uniaxiality.
The liquid crystal phase discotic liquid crystalline material is expressed, columnar liquid crystal phase, discotic nematic liquid crystal phase (N _D phase), and the like. Among these, a discotic nematic liquid crystal phase exhibiting good monodomain properties is preferable.
Note that the presence or absence of the liquid crystallinity of the material can be determined by observing with a polarizing microscope.

  Examples of discotic liquid crystalline materials include C.I. Benzene derivatives described in a research report of Destrade et al. (Mol. Cryst. 71, 111 (1981)), C.I. Destrode et al. (Mol. Cryst. 122, 141 (1985), Physics lett, A, 78, 82 (1990)). The cyclohexane derivatives described in the research report of Kohne et al. (Angew. Chem. 96, 70 (1984)) and M.M. Lehn et al. (JCS, Chem. Commun., 1794 (1985)), J.C. Azacrown-type and phenylacetylene-type macrocycles described in the research report of Zhang et al. (J. Am. Chem. Soc. 116, 2655 (1994)) are included.

The discotic liquid crystalline material includes a compound having a structure in which a linear alkyl group, an alkoxy group, and a substituted benzoyloxy group are radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the center of the molecule. The molecule or the assembly of molecules is preferably a compound having rotational symmetry and imparting a certain orientation.
The discotic liquid crystalline material does not require that the compound contained in the organic electroluminescent device finally has liquid crystallinity, and has, for example, a group in which a low molecular weight discotic liquid crystalline molecule reacts with heat or light. As a result, a compound which is polymerized or cross-linked by reaction with heat or light to become polymerized and loses liquid crystallinity is also included. Preferred examples of the discotic liquid crystalline material are described in JP-A-8-50206. Moreover, about superposition | polymerization of a discotic liquid crystalline material, Unexamined-Japanese-Patent No. 8-27284 has description.

  The discotic liquid crystal phase-isotropic phase transition temperature of the discotic liquid crystal material is preferably 50 to 300 ° C, more preferably 70 to 300 ° C, and particularly preferably 100 ° C to 300 ° C.

  Examples of the discotic liquid crystalline material include, but are not limited to, the following compounds.

In the above compound (D1) ~ (D11), L is as defined _{R T} in the general formula (T-I) described below.
In the compounds (D1) to (D11), (D1), (D3), (D5), (D9), and (D11) are preferable, and a triphenylene derivative represented by (D3) is more preferable.

(Triphenylene derivative showing liquid crystallinity)
Hereinafter, the triphenylene derivative represented by (D3) will be described. Hereinafter, (D4) is described again as the following general formula (TI).

In the above general formula (T-I), R _T represents R _T ¹ —, R _T ¹ —O—, R _T ¹ —CO—O—, or R _T ¹ —O—CO—. Although all the compounds having these groups are not discotic liquid crystalline, an appropriate group that exhibits discotic liquid crystallinity can be selected and used based on known techniques. Examples of R _T ¹ include an alkyl group, an alkyl group in which a ring such as a phenylene group or a cyclohexylene group is combined, an oxygen group in which an oxygen atom is arranged between carbon and carbon of the alkyl group, and the like.

The R _{T, ^{specifically, R T 2 -, R T}} 2 -O-Ph-, R T 2 -Ph-, R T 2 - (O-R T 3) nT -, R T 2 - ( ^{_{O-R T 3) nT -O-}} , R T 2 -O-, R T 2 -O-R T 3 -, -O- R T 2 -O-R T 3, R T 2 -O-Ph- COO—, R _T ² — (O—R _T ³ ) _nT —O—Ph—COO—, R _T ² —O—Ph—CH═CH—COO—, R _T ² —CH═CH—COO—, CH ₂ = CH—COO—R _T ³ —O—Ph—COO— is exemplified. Here, R _T ² represents an alkyl group which may have a polymerizable group, R _T ³ represents an alkylene group, Ph represents a phenylene group which may have a substituent, n _T , Is a repeating number _of- (O-R _T ³ )-and represents an integer of 1 or more.

Examples of the polymerizable group include a styryl group, an allyl group, an acrylic ester group, a methacrylic ester group, a crotonic ester group, an epoxy group, and the like. An allyl group is more preferable.
Carbon number of the alkyl group part in the alkyl group which may have a polymerizable group represented by R _T ² is preferably in the range of 1-20, more preferably in the range of 1-15, and further Preferably it is the range of 1-10.
Carbon number of the alkylene group represented by R _T ³ is preferably in the range of 1 to 10, more preferably in the range of 1 to 10, and further preferably in the range of 2 to 8.
Ph represents a phenylene group which may have a substituent. Examples of the substituent which may have a fluorine atom, an alkyl group, and an alkoxy group include an alkyl group and an alkoxy group from the viewpoint of liquid crystallinity. Groups are preferred. The number of carbon atoms of the alkyl group or alkoxy group as a substituent is preferably in the range of 1 to 10, more preferably in the range of 1 to 8, still more preferably in the range of 1 to 5.
n _{T ^{is, - (O-R T 3}} ) - number of repetitions of the represents an integer of 1 or more. n _T is preferably an integer of 1 to 10, more preferably an integer from 1 to 6, more preferably an integer of 1 to 3.

The R _T, in terms of liquid crystal phase ^{_{expression, R T 2 -, R T}} 2 -O-Ph-, R T 2 -Ph-, R T 2 - (O-R T 3) nT -, R T 2 -(O-R _T ³ ) _nT -O-, R _T ² -O-Ph-COO-, R _T ^2- (O-R _T ³ ) n _T -O-Ph-COO-, R _T ² -O ^{_{-Ph-CH = CH-COO-,}} R T 2 -CH = CH-COO- is preferred, in view of the organic EL device ^{_{performance, R T 2 -, R T}} 2 -O-Ph-, R T 2 -Ph ^{_{-, R T 2 - (O}} -R T 3) nT -, R T 2 - (O-R T 3) nT -O-, but more preferable.

  Preferred examples of the discotic liquid crystalline material include the following pyrene derivatives.

(Pyrene derivatives exhibiting liquid crystallinity)
As the pyrene derivative exhibiting liquid crystallinity, any conventionally known discotic liquid crystalline pyrene derivative can be used, and examples thereof include a pyrene derivative represented by the following general formula (PI).

In formula _{(P-I), R} P ^{_{is, R P 1 -, R P}} 1 -O-, means R P 1 -CO-O- or. p is the number of substituents and represents an integer of 1 to 5. Although all the compounds having these groups are not discotic liquid crystalline, an appropriate group that exhibits discotic liquid crystallinity can be selected and used based on known techniques. Examples of _RP ¹ include an alkyl group, an alkyl group in which a ring such as a phenylene group or a cyclohexylene group is combined, an oxygen group in which an oxygen atom is disposed between carbon and carbon of the alkyl group, and the like.

The R _{P, ^{specifically, R P 2 -, R P}} 2 -O-, R P 2 -O-R P 3 -, R P 2 -O-R P 3 -O-, R P 2 - ^{_{O-Ph-COO-, R P}} 2 - (O-R P 3) nP -O-Ph-COO-, R P 2 -O-Ph-CH = CH-COO-, CH 2 = CH-COO-R _P ³ —O—Ph—COO—, R _P ² —CH═CH—COO— may be mentioned. Here, R _P ² represents an alkyl group which may have a polymerizable group, R _P ³ represents an alkylene group, Ph represents a phenylene group which may have a substituent, n _P , Is a repeating number of — (O—R _P ³ ) — and represents an integer of 1 or more.

R _P ² represents an alkyl group which may have a polymerizable group, when having a polymerizable group, it is preferable from the viewpoint of the expression of the N _D phase having a polymerizable group at the top end of the alkyl group. Examples of the polymerizable group include an acrylic acid ester group, a methacrylic acid ester group, a crotonic acid ester group, and an epoxy group. From the viewpoint of polymerization speed, ease of synthesis, and cost, an acrylic acid ester group and a methacrylic acid ester group. Groups are preferred, and acrylate groups are more preferred.
The carbon number of the alkyl group moiety in the alkyl group which may have a polymerizable group represented by R _P ² is preferably in the range of 1-20, more preferably in the range of 1-15, and further Preferably it is the range of 1-10.
The number of carbon atoms of the alkylene group represented by R _P ³ is preferably in the range of 1 to 10, more preferably in the range of 1 to 9, and still more preferably in the range of 2 to 8.
Ph represents a phenylene group which may have a substituent. Examples of the substituent which may have a fluorine atom, an alkyl group, and an alkoxy group include an alkyl group and an alkoxy group from the viewpoint of liquid crystallinity. Groups are preferred. The number of carbon atoms of the alkyl group or alkoxy group as a substituent is preferably in the range of 1 to 10, more preferably in the range of 1 to 8, still more preferably in the range of 1 to 5.
n _{P ^{is, - (O-R P 3}} ) - number of repetitions of the represents an integer of 1 or more. n _P is preferably an integer of from 1 to 10, more preferably an integer from 1 to 6, more preferably an integer of 1 to 3.

The R _P, in terms of liquid crystal phase _{stabilization,} ^R P 2 -O- are preferred.
p is the number of substituents, preferably an integer of 1 to 3, more preferably an integer of 1 or 2. The pyrene derivative represented by the general formula (PI) preferably has a substituent at least at the 4-position of the benzene ring from the viewpoint of improving the aspect ratio by expanding the molecular size.

  The pyrene derivative represented by the general formula (P-I) is preferably a pyrene derivative represented by the following general formula (P-II) from the viewpoint of expansion of the liquid crystal temperature range.

In the general formula _{(P-II), R} P has the same meaning as _{R P} in the general formula (P-I).

Specific examples and preferred ranges of _{R P} in the general formula (P-II) are the same as those in general formula (P-I).

The molecular radius of the discotic liquid crystalline material is preferably 0.4 nm to 3 nm, more preferably 1.0 nm to 2.5 nm, and particularly preferably 1.0 nm to 2.0 nm.
The molecular radius of the discotic liquid crystalline host material is defined as the radius when the whole molecule including the side chain is a disk.
The molecular radius is defined as follows by theoretical calculation. The theoretical calculation here is performed using a density functional method. Specifically, using Gaussian 03 (Gaussian, USA), the basis function is 6-31G ^* and the exchange correlation functional is B3LYP / LANL2DZ. Perform optimization calculations. Using the optimized structure obtained by the structure optimization calculation, the molecular radius of the discotic liquid crystalline material is obtained.

  70 mass%-99.9 mass% are preferable with respect to the total solid, and, as for content of the liquid crystalline host material in the coating liquid for light emitting layer formation, 75 mass%-99 mass% are more preferable, and 80 mass%. -95% by weight is particularly preferred.

(Luminescent material)
The coating solution for forming the light emitting layer can contain a light emitting material.
The light emitting material has an aspect ratio (molecular core diameter / molecular core thickness) between the molecular core diameter and the molecular core thickness of at least 3 from the viewpoint of improving its own orientation without disturbing the alignment of the liquid crystalline host material. 3 to 30 is more preferable, and 4 to 20 is particularly preferable. The molecular core diameter means the longest molecular length of a chromophore (a chromophore linked by a conjugated system, a luminescent skeleton).
The molecular core diameter is defined as follows by theoretical calculation. The theoretical calculation here is performed using a density functional method. Specifically, using Gaussian 03 (US Gaussian), basis function: 6-31G ^* , exchange correlation functional: B3LYP / LANL2DZ
Then, the structure optimization calculation is performed. Using the optimized structure obtained by the structure optimization calculation, the length of the longest molecular length in the ball and stick display is defined as the molecular core diameter of the phosphorescent compound.
The molecular core thickness means the thickness of the molecule when the chromophore is a plane.
The molecular core thickness is also determined by the same method as the molecular core diameter, and the length in the thickness direction of the molecule in the ball and stick display is defined as the molecular core thickness.

The molecular radius of the light emitting material is preferably 0.40 nm to 3.0 nm, more preferably 0.80 nm to 2.5 nm, and particularly preferably 1.20 nm to 2.0 nm. This range is preferable from the viewpoints of improving the orientation, ease of controlling the emission intensity and emission wavelength, and the like.
Here, the molecular radius of the luminescent material is defined as the radius when the entire molecule including the side chain is a disk.
As with the molecular core diameter, the molecular radius is defined as follows by theoretical calculation. The theoretical calculation here is performed using a density functional method. Specifically, using Gaussian 03 (Gaussian, USA), the basis function is 6-31G ^* and the exchange correlation functional is B3LYP / LANL2DZ. Perform optimization calculations. Using the optimized structure obtained by the structure optimization calculation, the molecular radius of the light emitting material is obtained.
The molecular core thickness means the molecular thickness when the chromophore is a plane. The molecular core thickness is also obtained by the same method as the molecular core diameter, and the length in the thickness direction of the molecule in the ball and stick display is defined as the molecular core thickness.

  The size ratio between the molecular radius of the light emitting material and the molecular radius of the liquid crystalline host material (molecular radius of the light emitting material / molecular radius of the liquid crystalline host material) is 0.8 to 1.2, 0.85 to 1 .15 is more preferable, and 0.9 to 1.1 is particularly preferable. When the size ratio is within this range, the luminance in the front direction of the organic electroluminescent element increases. This is because even when a luminescent material is mixed with a liquid crystal host material, the orientation order (order parameter) of the liquid crystal host material is not lowered. It is presumed that the orientation direction of the material molecules becomes uniform. Note that the front direction of the organic electroluminescent element refers to a direction viewed from this direction, in which the organic electroluminescent element is placed upright and a perpendicular line is drawn from the substrate side to the light emitting layer.

There is no restriction | limiting in particular as a luminescent material, Although it can select suitably according to the objective, A phosphorescent luminescent material is preferable.
Examples of the light emitting material include a complex containing a transition metal atom. These may be used alone or in combination of two or more.
The complex may have one transition metal atom in the compound, or may be a so-called binuclear complex having two or more. Different metal atoms may be contained at the same time.

Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Listed by Yersin, “Photochemistry and Photophysics of Coordination Compounds”, published by Springer-Verlag, 1987, Akio Yamamoto, “Organic Metal Chemistry-Fundamentals and Applications,” published by Soukabo, 1982, etc. It is done.
Examples of the ligand include aromatic carbocyclic ligand, nitrogen-containing heterocyclic ligand, diketone ligand, carboxylic acid ligand, alcoholate ligand, carbon monoxide ligand, isonitrile coordination Child, cyano ligand and the like. Among these, a nitrogen-containing heterocyclic ligand is particularly preferable.
Examples of the aromatic carbocyclic ligand include a cyclopentadienyl anion, a benzene anion, and a naphthyl anion.
Examples of the nitrogen-containing heterocyclic ligand include phenylpyridine, benzoquinoline, quinolinol, bipyridyl, phenanthroline and the like.
Examples of the diketone ligand include acetylacetone.
Examples of the carboxylic acid ligand include an acetic acid ligand.
Examples of the alcoholate ligand include a phenolate ligand.

  Examples of the transition metal atom include ruthenium, rhodium, palladium, osmium, platinum and the like. Among these, platinum (platinum complex) which becomes tetradentate which is a planar coordination structure is preferable in that the aspect ratio is 3 or more, and a platinum complex having a salen or porphyrin skeleton is more preferable.

The platinum complex is preferably selected from phosphorescent compounds represented by the following general formulas (1) to (5).
General formula (1)

(In general formula (1), X, Y, and Z represent a carbon atom or a nitrogen atom, and when either Z or Y is a nitrogen atom and Y is a nitrogen atom, X is a carbon atom. M, n, p and q each independently represents an integer of 0 to 3. Ar represents an aryl group, R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group, Represents an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and q are 2 or more, a plurality of R _{1 to} R ₄ are connected to each other to form a cyclic structure May be formed.)

In general formula (1), X, Y, and Z represent a carbon atom or a nitrogen atom, and when either Z or Y is a nitrogen atom and Y is a nitrogen atom, X is a carbon atom. . Preferably, Z is a carbon atom, Y is a nitrogen atom, and X is a carbon atom.
m, n, p, and q each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, and more preferably 0 to 1. n is preferably 0 to 2, and more preferably 0 to 1. p is preferably 0 to 2, and more preferably 0 to 1. q is preferably 0 to 2, and more preferably 0 to 1.

R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms. Specifically, for example, methyl group, octyl group, decyl group, dodecyl group, n-butyl group, t-butyl group, t-amyl group, s- A butyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a hydrocarbon group having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. . The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
Among these, from the viewpoint of aspect ratio, in the case of a linear alkyl group or a group other than an alkyl group, it is preferable to have an alkyl group as a substituent.
R ₁ and R ₂ are preferably an alkyl group, an aryl group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an aryl group, and a phenyl group.
R ₃ and R ₄ are preferably an alkyl group or an aryl group, more preferably a methyl group, a trifluoromethyl group, or a phenyl group, and even more preferably a methyl group or a trifluoromethyl group.

Examples of the aryl group represented by Ar include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group represented by Ar may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group, preferably 1 to 6 carbon atoms. Are an alkyl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group (preferably a trifluoromethyl group), and more preferably an alkyl group having 1 to 6 carbon atoms and a fluorine atom. Ar is more preferably a phenyl group having a substituent, and the substituent is preferably a methyl group, a t-butyl group, a 4-pentyl-cyclohexyl group, a 4-pentyl-cyclohexylmethoxy group, or the like.
When m, n, p, q is 2 or more, a plurality of R _{1 to} R ₄ may be connected to each other adjacent to each other to form a cyclic structure.
General formula (2)

(In General Formula (2), X, Y, and Z represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. R, s, t and u each independently represents an integer of 0 to 3. R _{5 to} R ₈ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group. , A silyl group, or a heterocyclic group, and when r, s, t, and u are 2 or more, a plurality of R _{5 to} R ₈ may be connected to each other to form a cyclic structure. ₁ and W ₂ represent an alkyl group and may be bonded to each other to form a cyclic structure.

  In the general formula (2), X, Y, and Z are synonymous with X, Y, and Z in the general formula (1), and preferred ranges are also the same.

R < ₅ > -R < ₈ > is synonymous with R < ₁ > -R < ₄ > of General formula (1).
R ₅ and R ₆ are preferably an alkyl group, an alkoxy group, an aryl group, a fluorine atom, or a cyano group.
As the alkyl group represented by R ₅ and R ₆ , an optionally substituted methyl group, butyl group, octyl group, decyl group, dodecyl group and the like are preferable, and a butyl group, a trifluoromethyl group, an octyl group, A decyl group is more preferred.
The alkoxy group represented by R ₅ and R ₆ is preferably a decyloxy group.
The aryl group represented by R ₅ and R ₆ is preferably a phenyl group which may have a substituent, and the substituent is preferably an alkyl group, more preferably a propyl group or a butyl group.
R ₇ and R ₈ are preferably an alkyl group or an aryl group.

r, s, t, and u each independently represent an integer of 0 to 3. Among these, r is preferably 0 to 2, and more preferably 0 or 1. s is preferably 0 to 2, more preferably 0 or 1. t is preferably 0 or 1, and u is preferably 0 or 1.
When r, s, t, u is 2 or more, the plurality of R _{5 to} R ₈ may be connected to each other adjacent to each other to form a cyclic structure. Examples of the cyclic structure include a benzofuran ring.

W ₁ and W ₂ represent an alkyl group having 1 to 10 carbon atoms and may be bonded to each other to form a cyclic structure.
Examples of the alkyl group represented by W ₁ and W ₂ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and a pentyl group.
Examples of the cyclic structure formed by combining W ₁ and W ₂ include a cyclohexyl cyclic structure.
W ₁ and W ₂ are preferably a methyl group or a cyclohexyl cyclic structure from the viewpoint of a high aspect ratio.
General formula (3)

(In General Formula (3), R _{9 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ may combine with each other to form a cyclic structure.)

In General Formula (3), R _{9 to} R ₁₆ represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ may be bonded to each other to form a cyclic structure.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. As said alkyl group, C1-C12 is preferable, for example, a methyl group, an octyl group, a decyl group, a dodecyl group, n-butyl group, t-butyl group, t-amyl group, s-butyl group etc. are mentioned. It is done.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specifically includes, for example, methoxy group, pentyloxy group, octyloxy group, decyloxy group, dodecyloxy group, s-octyloxy group, benzyloxy group, and the like. Can be mentioned.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, and may be condensed. Specifically, for example, a phenyloxy group, a toluyloxy group, a naphthyloxy group Etc.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. As said silyl group, C3-C18 is preferable and a trimethylsilyl group, t-butyldimethylsilyl group, a triphenylsilyl group, t-butyldiphenylsilyl group, etc. are mentioned.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.

R _{9 to} R ₁₀ are preferably a hydrogen atom or a heteroaromatic ring in which R ₉ and R ₁₁ , and R ₁₀ and R ₁₂ are bonded to each other. Examples of the heteroaromatic ring include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a triazole ring, an oxadiazole ring, and a thiadiazole ring. Preferably, it is a pyridine ring.
R _{13, R 14,} R _{15, R 16 is} preferably _{R 13} and _{R 16, R 14} and _{R 15} is an aromatic ring bonded respectively. Examples of the aromatic ring include a benzene ring.
R ₁₁ and R ₁₂ preferably represent a hydrogen atom, an alkyl group, or an aromatic ring in which R ₁₁ and R ₁₂ are bonded. Examples of the aromatic ring to which R ₁₁ and R ₁₂ are bonded include a benzene ring or a naphthalene ring.
Heteroaromatic ring in which R ₉ and R ₁₁ , R ₁₀ and R ₁₂ are bonded, and R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are aromatic rings in which R ₁₃ and R ₁₆ , R ₁₄ and R ₁₅ are bonded, respectively. May have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, and a fluorine atom, and include a methyl group, an n-butyl group, a t-butyl group, an s-butyl group, and an undecyl group. , Butoxy group, pentyloxy group, decyloxy group, dodecyloxy group and fluorine atom are preferred.
Among these, an aromatic ring in which R ₁₃ and R ₁₆ , R ₁₄ and R ₁₅ , and R ₁₁ and R ₁₂ are bonded from the viewpoint of aspect ratio and molecular size is preferable.

As a more preferable aspect of the compound represented by General formula (3), the compound of following General formula (6) is mentioned.
General formula (6)

In the structural formula (6), B may form either an aromatic or non-aromatic 6-membered ring.
R _{17 to} R ₂₆ represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and R ₁₇ and R ₁₈ , R ₁₈ and R ₁₉ , R ₁₉ and R ₂₀ , R ₂₁ and R ₂₂ , R ₂₂ and R ₂₃ , R ₂₃ and R ₂₄ , and R ₂₅ and R ₂₆ may be bonded to each other to form a cyclic structure.
R ₁₇ , R ₂₀ , R ₂₁ and R ₂₄ are preferably a hydrogen atom or an alkyl group.
R ₁₈ , R ₁₉ , R ₂₂ and R ₂₃ are preferably an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an alkoxy group, a decyloxy group or a dodecyl group. An oxy group is more preferable.
R _{25 to} R ₂₆ are preferably a hydrogen atom, an alkyl group, a fluorine atom, or an aromatic ring in which R ₂₅ and R ₂₆ are bonded.
B is preferably a non-aromatic 6-membered ring, more preferably a pyridine ring. The ring may have a substituent, and examples of the substituent include an alkyl group (methyl group, butyl group).
From the viewpoint of the aspect ratio, R _{17 to} R ₂₆ preferably have an alkyl group as a substituent in the case of a chain alkyl group or a group other than an alkyl group.
General formula (4)

(In General Formula (4), X, Y, and Z represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. M, n, p and g each independently represents an integer of 0 to _3. Ar represents an aryl group, R _{1 to} R ₃ and R ₃₀ , each independently an alkyl group, an aryl group, an alkoxy group, An aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and g are 2 or more, a plurality of R _{1 to} R ₃ and R ₃₀ are connected to each other adjacent to each other. A cyclic structure may be formed, and M and Q are each independently a carbon atom or a nitrogen atom.)

In General Formula (4), R _{1 to} R ₃ , Ar, X, Y, Z, m, n, and p have the same meanings as in General Formula (1), and preferred ranges are also the same.
M and Q are each independently a carbon atom or a nitrogen atom.
g represents an integer of 0 to 3, and an integer of 0 to 2 is preferable.

R ₃₀ represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms. Specifically, for example, methyl group, octyl group, decyl group, dodecyl group, n-butyl group, t-butyl group, t-amyl group, s- A butyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, and may be condensed, and specifically includes a phenyloxy group, a toluyloxy group, a naphthyloxy group, and the like. Can be mentioned.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
R ₃₀ is preferably a fluorine atom.
From the viewpoint of aspect ratio, R ₃₀ preferably has an alkyl group as a substituent in the case of a chain alkyl group or a group other than an alkyl group.
General formula (5)

(In General Formula (5), Z represents a carbon atom or a nitrogen atom. M, n, and g each independently represents an integer of 0 to _3. Ar represents an aryl group. R ₁ , R _2, and R ₃₀ independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, or g is 2 or more, a plurality of R ₁ , R ₂ and R ₃₀ may be linked to each other to form a cyclic structure, and M and Q are each independently a carbon atom or a nitrogen atom.)

In general formula (5), R ₁ , R ₂ , Ar, Z, m, and n have the same meanings as in general formula (1), and the preferred ranges are also the same. Furthermore, M, _{Q, R 30,} g is the general formula (4) synonymous, and their preferable ranges are also the same.

  Examples of the phosphorescent compounds represented by the general formulas (1) to (5) include, but are not limited to, the following compounds.

The platinum complexes represented by the general formulas (1) to (5) are described in, for example, Journal of Organic Chemistry 53,786, (1988), G.A. R. Newkome et al. ), Page 789, method described in left line 53 to right line 7, line 790, method described in left line 18 to line 38, method 790, method described in right line 19 line to line 30 and The combination, Chemische Berichte 113, 2749 (1980), H.C. Lexy et al.), Page 2752, lines 26-35, and the like.
For example, a ligand or a dissociated product thereof and a metal compound are mixed with a solvent (for example, a halogen solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfone solvent, In the presence of a sulfoxide solvent, water, etc., or in the absence of a solvent, in the presence of a base (inorganic and organic bases such as sodium methoxide, t-butoxypotassium, triethylamine, potassium carbonate, etc.) Or in the absence of a base, at room temperature or below, or by heating (in addition to normal heating, a method of heating with a microwave is also effective).

  The content of the luminescent material in the coating solution for forming the luminescent layer is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 25% by mass, and more preferably 5% by mass to 20% by mass with respect to the total solid content. Mass% is particularly preferred.

(Other compounds)
The coating solution for forming the light emitting layer may further contain a fluorine atom-containing compound and other additives.

(Fluorine atom-containing compound)
The fluorine atom-containing compound has the property of being localized on the air interface side in the light emitting layer, and by incorporating the fluorine atom containing compound in the light emitting layer, the liquid crystalline host material and the light emitting material are effective against the anode. In particular, it can be oriented in the horizontal direction, which is preferable from the viewpoint of improving the light extraction efficiency.

The fluorine atom-containing compound preferably has 3 or more side chain substituents containing 4 or more fluorine atoms from the viewpoint of localization on the air interface side, solvent solubility, and film-forming property. 18 is more preferable, and 4 to 12 is particularly preferable. From the same viewpoint, it is preferable that 4 or more fluorine atoms are contained per side chain substituent, more preferably 6 to 30 atoms, and particularly preferably 8 to 25 atoms. The number of fluorine atoms can be measured by elemental analysis, MASS, ¹ H-NMR, ¹⁹ F-NMR.

  As the fluorine atom-containing compound, for example, compounds represented by the following structural formulas (A) and (B) are preferable.

In the structural formula (A), R ₂₇ and R ₂₈ each independently represents a substituted or unsubstituted alkyl group having 4 or more fluorine atoms, —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₆ H, —CH ₂ (CF ₂ ) ₈ H, — (CH ₂ ) ₃ C ₄ F ₉ , —CH ₂ CH ₂ OCH ₂ CH ₂ C ₆ F _{13 and the} like are preferable.

In Structural Formula (B), R ₂₉ represents a substituted or unsubstituted alkyl group or acyl group having 4 or more fluorine atoms, —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₆ H, _{-CH 2 (CF 2) 8 H} , - (CH 2) 3 C 4 F 9, such as _{-CH 2 CH 2 OCH 2 CH 2} C 6 F 13 are preferred.

  The content of the fluorine atom-containing compound in the coating solution for forming the light emitting layer is preferably 0.0001% by mass to 5% by mass, more preferably 0.001% by mass to 2% by mass with respect to the total solid content. 01 mass%-1 mass% are especially preferable.

(solvent)
Examples of the solvent of the coating solution for forming the light emitting layer include organic solvents such as hydrocarbon solvents, ketone solvents, halogenated hydrocarbon solvents, alcohol solvents, ether solvents, and ester solvents.
Examples of the hydrocarbon solvent include hexane, octane, decane, toluene, xylene, ethylbenzene, 1-methylnaphthalene, 1,2-dichlorobenzene, and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, tetrachloromethane, dichloroethane, trichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene, chlorotoluene and the like.
Examples of the alcohol solvent include methanol, propanol, butanol, pentanol, hexanol, cyclohexanol, methyl cellosolve, ethyl cellosolve, and ethylene glycol.
Examples of the ether solvent include dibutyl ether, tetrahydrofuran, dioxane, anisole and the like.
Examples of the ester solvent include ethyl acetate, butyl acetate, and amyl acetate.
The solid content with respect to the solvent in the coating solution is not particularly limited, and the viscosity of the coating solution can be arbitrarily selected according to the film forming method.

It is preferable to orient the transition dipole moment of the phosphorescent material horizontally with respect to the anode by the method for producing an organic electroluminescent element of the present invention. The transition dipole moment of the luminescent material is oriented horizontally with respect to the anode, which is advantageous in that the light emission component in the direction perpendicular to the anode is increased and the light extraction efficiency is improved.
The direction of the transition dipole moment is defined as follows by theoretical calculation. The theoretical calculation here is performed using Gaussian 03 (Gaussian, USA). As the molecular structure used for the calculation, the direction of the transition dipole moment can be obtained by performing the structure optimization calculation and using the structure having the minimum generation energy.
Or after forming a light emitting layer, it can also measure by an ATR-IR measuring method or a grazing incidence UV measuring method.

  In the method for producing an organic electroluminescent element of the present invention, it is preferable that the liquid crystalline host material is applied and formed at a temperature at which a liquid crystal phase can be developed, and then the molecular orientation state of the liquid crystalline host material is maintained and fixed. . The immobilization is preferably performed by a polymerization method or a liquid crystal phase-glass transition. As the polymerization reaction, a thermal polymerization reaction or a photopolymerization reaction using a polymerization initiator can be used, but from the viewpoint of device performance, a method not using a polymerization initiator is preferable, and a thermal polymerization reaction using a styryl group or a silane is preferable. Examples thereof include a sol-gel hardening method using a coupling agent.

Examples of the polymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin compounds (US). Patent No. 2722512), a polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (described in US Pat. No. 3,549,367), acridine and phenazine Compounds (described in JP-A-60-105667 and US Pat. No. 4,239,850) and oxadiazole compounds (described in US Pat. No. 4,221,970) are included.
The content of the polymerization initiator in the coating solution for forming the light emitting layer is preferably 0.001% by mass to 5% by mass and more preferably 0.001% by mass to 1% by mass with respect to the total solid content.

In the method for producing an organic electroluminescent element of the present invention, at least a part of the liquid crystalline host material may be uniaxially aligned by further irradiating the light-emitting layer formed by coating. Examples of the light to be irradiated include ultraviolet rays linearly polarized in one direction or electron beams. Among these, ultraviolet rays are preferably used. The irradiation energy of light irradiation ^is preferably ^{20mJ / cm 2 ~50J / cm 2} , more preferably ^{20~5,000mJ / cm 2, 100mJ / cm} 2 ~800mJ / cm 2 is particularly preferred. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

[Organic electroluminescence device]
The organic electroluminescent element in the present invention will be described in detail.
The organic electroluminescent element in the present invention includes a light emitting layer formed by the above-described method for producing an organic electroluminescent element. A preferred embodiment is an organic electroluminescence device having a pair of electrodes including an anode and a cathode and at least one organic layer including a light emitting layer between the electrodes on a substrate.

In the organic electroluminescent element of the present invention, the light emitting layer is an organic layer, and further includes at least one organic layer between the light emitting layer and the anode, but may further have an organic layer in addition to these.
In view of the properties of the light-emitting element, at least one of the anode and the cathode is preferably transparent or translucent.
FIG. 1 shows an example of the configuration of an organic electroluminescent device according to the present invention.
In the organic electroluminescent element 10 according to the present invention shown in FIG. 1, a light emitting layer 6 is sandwiched between an anode 3 and a cathode 9 on a support substrate 2. Specifically, a hole injection layer 4, a hole transport layer 5, a light emitting layer 6, a hole block layer 7, and an electron transport layer 8 are laminated in this order between the anode 3 and the cathode 9.

<Structure of organic layer>
There is no restriction | limiting in particular as a layer structure of the said organic layer, Although it can select suitably according to the use and objective of an organic electroluminescent element, It is preferable to form on an anode or a cathode. In this case, the organic layer is formed on the front surface or one surface on the anode or the cathode.
There is no restriction | limiting in particular about the shape of a organic layer, a magnitude | size, thickness, etc., According to the objective, it can select suitably.

Specific examples of the layer configuration include the following, but the present invention is not limited to these configurations.
Anode / hole transport layer / light emitting layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode.
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode.
The element configuration, the substrate, the cathode, and the anode of the organic electroluminescence element are described in detail in, for example, Japanese Patent Application Laid-Open No. 2008-270736, and the matters described in the publication can be applied to the present invention.

<Board>
The substrate used in the present invention is preferably a substrate that does not scatter or attenuate light emitted from the organic layer. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.

<Anode>
The anode usually only needs to have a function as an electrode for supplying holes to the organic layer, and there is no particular limitation on the shape, structure, size, etc., depending on the use and purpose of the light-emitting element, It can select suitably from well-known electrode materials. As described above, the anode is usually provided as a transparent anode.

<Cathode>
The cathode usually has a function as an electrode for injecting electrons into the organic layer, and there is no particular limitation on the shape, structure, size, etc., and it is known depending on the use and purpose of the light-emitting element. The electrode material can be selected as appropriate.

  Regarding the substrate, anode, and cathode, the matters described in paragraphs [0070] to [0089] of JP-A-2008-270736 can be applied to the present invention.

<Organic layer>
The organic layer in the present invention will be described.

[Formation of organic layer]
In the organic electroluminescent device of the present invention, each organic layer other than the light emitting layer may be any one of a dry coating method such as a vapor deposition method and a sputtering method, a solution coating process such as a transfer method, a printing method, a spin coating method, and a bar coating method. Also, it can be suitably formed. When the wet method is used, the organic layer can be easily increased in area, and a light-emitting element having high luminance and excellent light emission efficiency can be obtained efficiently at low cost, which is preferable. Vapor deposition, sputtering, etc. can be used as dry methods, and dipping, spin coating, dip coating, casting, die coating, roll coating, bar coating, gravure coating, and spray coating as wet methods. An ink jet method or the like can be used. These film forming methods can be appropriately selected according to the material of the organic layer. When the film is formed by a wet method, it may be dried after the film is formed. Drying is performed by selecting conditions such as temperature and pressure so that the coating layer is not damaged.

The coating solution used in the wet film-forming method (coating process) usually comprises an organic layer material and a solvent for dissolving or dispersing it. A solvent is not specifically limited, What is necessary is just to select according to the material used for an organic layer. Specific examples of the solvent include halogen solvents (chloroform, carbon tetrachloride, dichloromethane, 1,2-dichloroethane, chlorobenzene, etc.), ketone solvents (acetone, methyl ethyl ketone, diethyl ketone, n-propyl methyl ketone, cyclohexanone, etc.), Aromatic solvents (benzene, toluene, xylene, etc.), ester solvents (ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, diethyl carbonate, etc.), ether solvents (Tetrahydrofuran, dioxane, etc.), amide solvents (dimethylformamide, dimethylacetamide, etc.), dimethyl sulfoxide, alcohol solvents (methanol, propanol, butanol, etc.), water and the like.
The solid content with respect to the solvent in the coating solution is not particularly limited, and the viscosity of the coating solution can be arbitrarily selected according to the film forming method.

[Light emitting layer]
In the organic electroluminescent device of the present invention, the light emitting layer preferably contains at least one liquid crystalline host material and a light emitting material.
As the light emitting material, from the viewpoint of orientation, the light emitting material having high planarity described above is preferable, a phosphorescent light emitting material is preferable, and a platinum complex is more preferable. A luminescent material may be used independently or may use 2 or more types together.

  Although content in particular of the luminescent material in a light emitting layer is not restrict | limited, For example, it is preferable that it is 0.1-30 mass%, it is more preferable that it is 1-25 mass%, and it is 5-20 mass%. Particularly preferred.

The host compound is a compound that causes energy transfer from the excited state to the light-emitting material, and as a result, causes the light-emitting material to emit light. Alternatively, a compound that transmits holes or electrons and recombines them on the light emitting material to assist the light emitting material in an excited state may be used.
In the present invention, the liquid crystal host material described above is contained. 70 mass%-99.9 mass% are preferable, as for content in this light emitting layer of this liquid crystalline host material, 75 mass%-99 mass% are more preferable, and 80 mass%-95 mass% are especially preferable.

  As the host material, materials other than the above-mentioned liquid crystalline host materials may be contained. Specific examples thereof include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline. Derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds , Porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidene derivatives Derivatives, distyrylpyrazine derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal complexes having metal phthalocyanine, benzoxazole, benzothiazole, etc. as ligands, polysilanes Examples thereof include conductive polymers such as compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, polythiophenes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, and the like. A host compound may be used individually by 1 type, or may use 2 or more types together.

  The light emitting layer may contain the aforementioned fluorine atom-containing compound. The content of the fluorine atom-containing compound in the light emitting layer is preferably 0.0001% by mass to 5% by mass, more preferably 0.001% by mass to 2% by mass, and 0.01% by mass to 1% with respect to the total solid content. Mass% is particularly preferred.

  The thickness of the light emitting layer is preferably 10 to 200 nm, more preferably 20 to 80 nm, from the viewpoint of suppressing an increase in driving voltage and preventing a short circuit.

(Hole injection layer, hole transport layer)
The organic electroluminescent element of the present invention may have a hole injection layer and a hole transport layer. The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side.
The hole injection layer and the hole transport layer are described in detail, for example, in JP-A-2008-270736 and JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

(Electron injection layer, electron transport layer)
The organic electroluminescent element of the present invention may have an electron injection layer and an electron transport layer. The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injection material and the electron transport material used for these layers may be a low molecular compound or a high molecular compound.
The electron injection layer and the electron transport layer are described in detail, for example, in JP-A-2008-270736 and JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

(Hole blocking layer)
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. In the present invention, a hole blocking layer can be provided as an organic layer adjacent to the light emitting layer on the cathode side.
As an example of the organic compound constituting the hole blocking layer, aluminum (III) bis (2-methyl-8-quinolinato) 4-phenylphenolate (Aluminum (III) bis (2-methyl-8-quinolinato) 4- aluminum complexes such as phenylphenolate (abbreviated as BAlq), triazole derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10-) phenanthroline derivatives such as phenanthroline (abbreviated as BCP), triphenylene derivatives, carbazole derivatives, and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm.
The hole blocking layer may have a single layer structure made of one or more of the materials described above, or may have a multilayer structure made of a plurality of layers having the same composition or different compositions.

(Electronic block layer)
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side. In the present invention, an electron blocking layer can be provided as an organic layer adjacent to the light emitting layer on the anode side.
As an example of the organic compound constituting the electron blocking layer, for example, those mentioned as the hole transport material described above can be applied.
The thickness of the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm.
The electron blocking layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

[Other organic layers]
The organic electroluminescent device of the present invention has a protective layer described in JP-A-7-85974, 7-192866, 8-22891, 10-275682, 10-106746, etc. Also good. The protective layer is formed on the uppermost surface of the light emitting element. Here, when the base material, the transparent electrode, the organic layer, and the back electrode are laminated in this order, the top surface refers to the outer surface of the back electrode, and the base material, the back electrode, the organic layer, and the transparent electrode are laminated in this order. In some cases, it refers to the outer surface of the transparent electrode. The shape, size, thickness and the like of the protective layer are not particularly limited. The material for forming the protective layer is not particularly limited as long as it has a function of suppressing intrusion or permeation of a light-emitting element such as moisture or oxygen into the element. Silicon, germanium oxide, germanium dioxide or the like can be used.

  The method for forming the protective layer is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular sensing epitaxy, cluster ion beam, ion plating, plasma polymerization, plasma CVD, laser CVD Thermal CVD method, coating method, etc. can be applied.

[Sealing]
The organic electroluminescent element is preferably provided with a sealing layer for preventing moisture and oxygen from entering. As a material for forming the sealing layer, a copolymer of tetrafluoroethylene and at least one comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, polyethylene, polypropylene, polymethyl methacrylate, polyimide, Polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, chlorotrifluoroethylene or a copolymer of dichlorodifluoroethylene and another comonomer, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0. 1% or less moisture-proof material, metal (In, Sn, Pb, Au, Cu, Ag, Al, Tl, Ni, etc.), metal oxide (MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, _{CaO, BaO, Fe 2 O 3} , Y 2 O 3, TiO 2 , etc.), metal fluorides (M _{F 2, LiF, AlF 3,} CaF 2 , etc.), liquid fluorinated carbon (perfluoroalkane, perfluoro amines, perfluoroether, etc.), the liquid fluorinated carbon as dispersed adsorbent moisture or oxygen, etc. Can be used.

  The organic electroluminescence device of the present invention emits light by applying a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. Obtainable.

  The driving method of the organic electroluminescence device of the present invention is described in JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-2441047. The driving methods described in each publication, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429, 6023308, and the like can be applied.

The present invention will be described more specifically with reference to the following examples. The materials, reagents, substance amounts and ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.
Hereinafter, the mixing ratio of the solvent represents a volume ratio.

(Synthesis Example 1)
<Synthesis of phosphorescent compound 1>

-Synthesis of Compound 1a-
2,4-Dihydroxybenzaldehyde (20 g), n-decyl bromide (32 g) and potassium carbonate (20 g) were mixed in 200 ml of DMAc (dimethylacetamide) and reacted at 60 ° C. for 4 hours. The reaction solution was filtered, and the obtained filtrate was poured into ethyl acetate / saturated brine, and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/10) to obtain Compound 1a (20.3 g).
-Synthesis of Compound 1b-
To an ethanol solution (30 ml) of compound 1a (3 g) and 4,5-dimethyl-1,2-phenylenediamine (0.73 g), 5 drops of acetic acid was dropped with a 1 ml Komagome pipette and reacted at 80 ° C. for 6 hours. The precipitated solid was collected by filtration and recrystallized with ethanol to obtain Compound 1b (2.7 g).
-Synthesis of phosphorescent compound 1-
To a solution of compound 1b (1.5 g) and sodium acetate (0.19 g) in acetonitrile (30 ml), a solution of PtCl ₂ (0.61 g) in DMSO (dimethyl sulfoxide) (15 ml) was added dropwise at 80 ° C. for 7 hours. Reacted. The reaction solution is concentrated under reduced pressure, and the resulting solid is washed with ethanol, purified by silica gel column chromatography (developing solvent: chloroform / hexane = 8/1), and recrystallized from ethyl acetate to obtain a phosphorescent compound. 1 (0.72 g) was obtained. The compound was identified by elemental analysis, NMR and MASS spectrum. The appearance was a yellow solid.
The molecular core diameter, molecular core thickness, and molecular radius of phosphorescent compound 1 were calculated by performing structural optimization with Gaussian 03 (US Gaussian). As a result, the aspect ratio was 12.3, and the molecular radius was 1.91 nm.

(Synthesis Example 2)
<Synthesis of phosphorescent compound 2>

-Synthesis of Compound 2b-
Three drops of acetic acid were added dropwise to a solution of compound 1a (4 g) synthesized in Example 1 and ethylenediamine (0.43 g) in ethanol (40 ml) with a 1 ml Komagome pipette and reacted at 80 ° C. for 6 hours. The precipitated solid was collected by filtration and recrystallized with ethanol to obtain Compound 2b (3.9 g).
-Synthesis of phosphorescent compound 2-
To a acetonitrile solution (60 ml) of compound 2b (3.7 g) and sodium acetate (0.52 g), a DMSO solution (30 ml) of PtCl ₂ (1.7 g) was added dropwise at 80 ° C. and reacted for 7 hours. The reaction solution is concentrated under reduced pressure, and the resulting solid is washed with ethanol, purified by silica gel column chromatography (developing solvent: chloroform / hexane = 9/1), and heated and washed with isopropyl alcohol to obtain a phosphorescent compound. 2 (2.1 g) was obtained. The compound was identified by elemental analysis, NMR and MASS spectrum. The appearance was a yellow solid.
The molecular core diameter, molecular core thickness and molecular radius of the phosphorescent compound 2 were calculated by optimizing the structure with Gaussian 03 (Gaussian, USA). As a result, the aspect ratio was 4.5, and the molecular radius was 1.91 nm.

(Synthesis Example 3)
<Synthesis of phosphorescent compound 3>

-Synthesis of Compound 3b-
Two drops of acetic acid were added dropwise to a solution of compound 1a (4.37 g) synthesized in Example 1 and o-phenylenediamine (0.85 g) in ethanol (45 ml) with a 1 ml Komagome pipette and reacted at 80 ° C. for 3 hours. The precipitated solid was collected by filtration and recrystallized from ethanol to obtain Compound 3b (3.7 g).
-Synthesis of phosphorescent compound 3-
A DMSO solution (30 ml) of PtCl ₂ (1.27 g) was added dropwise at 80 ° C. to an acetonitrile solution (60 ml) of compound 3b (3 g) and sodium acetate (0.39 g), and the mixture was reacted for 7 hours. The reaction solution is concentrated under reduced pressure, and the resulting solid is washed with ethanol, purified by silica gel column chromatography (developing solvent: chloroform / hexane = 6/1), and recrystallized from ethyl acetate to obtain a phosphorescent compound. 3 (1.8 g) was obtained. The compound was identified by elemental analysis, NMR and MASS spectrum. The appearance was a yellow solid.
The molecular core diameter, molecular core thickness, and molecular radius of the phosphorescent compound 3 were calculated by performing structural optimization with Gaussian 03 (US Gaussian). As a result, the aspect ratio was 12.3, and the molecular radius was 1.91 nm.

(Synthesis Example 4)
<Synthesis of phosphorescent compound 4>

-Synthesis of Compound 4a-
Bromine (5 ml) was added dropwise to a sulfuric acid solution (46 ml) of 1,2-dinitrobenzene (4.6 g) and silver sulfate (17 g), reacted at 100 ° C. for 30 minutes, then reacted at 120 ° C. for 30 minutes, The reaction was carried out at 180 ° C. for 6 hours. After completion of the reaction, the reaction solution was poured into ice water, and the precipitated solid was filtered. Ethyl acetate was added to the obtained filtrate, and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/5) and recrystallized from hexane / ethyl acetate = 6/1 to obtain Compound 4a (1.6 g).
-Synthesis of Compound 4b-
Triethylamine (1.27 ml) was added dropwise to a THF (tetrahydrofuran) solution (24 ml) of compound 4a (0.6 g), copper iodide (35 mg), tetrakistriphenylphosphine palladium (106 mg), and 1-undecyl (0 .77 ml) was added dropwise and allowed to react for 12 hours at room temperature under a nitrogen atmosphere. The reaction solution was poured into ethyl acetate / dilute hydrochloric acid (mixing ratio: ethyl acetate / dilute hydrochloric acid = 1/1), and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/40, after development, 1/20) to obtain Compound 4b (0.34 g).
-Synthesis of Compound 4c-
To 10% Pd / C (63 mg), an ethanol solution (10 ml) of compound 4b (0.33 g) was added dropwise, and then saturated hydrazine (4.93 g) was added dropwise and reacted at 85 ° C. for 5 hours. The reaction mixture was filtered through celite and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/1) to obtain Compound 4c (0.27 g).
-Synthesis of Compound 4d-
To a solution of compound 4c (0.19 g) and compound 1a (0.15 g) in ethanol (3 ml), 1 drop of acetic acid was dropped with a 1 ml Komagome pipette at 70 ° C. and reacted for 6 hours. After concentration under reduced pressure, the concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/6) to obtain Compound 4d (0.28 g).
-Synthesis of phosphorescent compound 4-
To a solution of compound 4d (0.2 g) and sodium acetate (37 mg) in acetonitrile (7 ml), a DMSO solution (3.5 ml) of PtCl ₂ (62 mg) was added dropwise at 80 ° C. and reacted for 5 hours. The reaction solution was concentrated under reduced pressure, and the concentrated residue was purified by silica gel column chromatography (developing solvent: chloroform / hexane = 1/1) to obtain phosphorescent compound 4 (0.22 g). The compound was identified by elemental analysis, NMR and MASS spectrum. The appearance was a yellow amorphous solid.
The molecular core diameter, molecular core thickness and molecular radius of the phosphorescent compound 4 were calculated by optimizing the structure with Gaussian 03 (US Gaussian Co., Ltd.). As a result, the aspect ratio was 12.3, and the molecular radius was 1.91 nm.

(Synthesis Example 5)
<Synthesis of phosphorescent compound 5>

-Synthesis of Compound 5a-
A 1M THF solution (130 ml) of LAH (lithium aluminum hydride) was mixed with 100 ml of THF, and a solution of trans-4-pentylcyclohexanecarboxylic acid (23.5 g) in THF (80 ml) was added for 1.5 hours under ice cooling. It was dripped over. After dripping, it was made to react at room temperature for 1.5 hours, and was then made to react at 80 degreeC for 2 hours. The reaction solution was poured into 1N hydrochloric acid ice water and extracted with ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/40, after development, ethyl acetate / hexane = 1/5) to obtain compound 5a (21.9 g).
-Synthesis of Compound 5b-
Phosphorus tribromide (16.8 ml) was added dropwise to an acetonitrile solution (360 ml) of compound 5a (21.9 g) at room temperature, and the mixture was stirred at 45 ° C. for 3 hours. After cooling to room temperature, potassium bromide (50 g) was added over 15 minutes. Further, pyridine (30 ml) was added dropwise, followed by reaction at 80 ° C. for 3 hours. The reaction solution was poured into ethyl acetate / ice water (mixing ratio: ethyl acetate / ice water = 1/1), the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: hexane) to obtain Compound 5b (25.1 g).
-Synthesis of Compound 5c-
To a solution of Compound 5b (24.1 g) and 2,6-dimethyl-4-nitrophenol (17.9 g) in NMP (N-methylpyrrolidone) (240 ml) was added potassium carbonate (20.2 g), After the reaction for 5 hours, the reaction was performed at 100 ° C. for 2.5 hours. Furthermore, after reacting at 130 ° C. for 2 hours, the mixture was poured into 1N aqueous hydrochloric acid / ethyl acetate (mixing ratio: 1N aqueous hydrochloric acid / ethyl acetate = 1/1). The organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: hexane, developed, ethyl acetate / hexane = 1/10), and the resulting crude product was washed with methanol to obtain Compound 5c (23.7 g).
-Synthesis of Compound 5d-
Reduced iron (27.8 g), ammonium chloride (2.7 g), isopropyl alcohol (290 ml) and water (29 ml) were placed in a three-necked flask and stirred with a mechanical stirrer at 95 ° C. (300 rpm). After a small amount of concentrated hydrochloric acid was added dropwise to activate, compound 5c (23.7 g) was added little by little. After stirring for 3 hours under reflux with heating, the reaction mixture was filtered through Celite. The filtrate was poured into ethyl acetate / sodium bicarbonate aqueous solution (mixing ratio: ethyl acetate / sodium bicarbonate aqueous solution = 1/1), and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. did. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/10, 1/5 after development) to obtain Compound 5d (21.3 g).
-Synthesis of Compound 5e-
4-methylpyrazole (5.0 g), 1-chloro-3-iodobenzene (9.68 g), Cu ₂ O (0.29 g) cesium carbonate (26.46 g) and salicylaldehyde oxime (manufactured by Kanto Chemical) (1 .11 g) of DMAc solution (100 ml) was reacted at 140 ° C. for 5 hours under a nitrogen atmosphere. Ethyl acetate was added to the reaction mixture, and the mixture was filtered through celite. The filtrate was poured into saturated brine, and after liquid separation, the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/7) to obtain Compound 5e (6.35 g).
-Synthesis of Compound 5f-
Compound 5e (1.0 g), Compound 5d (0.72 g), t-butoxy potassium (1.1
3 g), Pd (dba) ₂ (27 mg) and 2- (di-t-butylphosphino) biphenyl (manufactured by Wako Pure Chemical Industries, Ltd.) (56.4 mg) in toluene solution (10 ml) at 110 ° C. under nitrogen atmosphere. Reacted for 6 hours. Ethyl acetate and water were added to the reaction solution, and after liquid separation, the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/9) to obtain Compound 5f (0.65 g).
-Synthesis of phosphorescent compound 5-
A benzonitrile solution (3 ml) of compound 5f (0.4 g) and PtCl ₂ (0.17 g) was reacted at 190 ° C. for 24 hours under a nitrogen atmosphere. After the reaction, benzonitrile was distilled off under reduced pressure, and the concentrated residue was purified by silica gel column chromatography (developing solvent: chloroform / hexane = 7/1). The obtained solid was washed with ethanol and then with ethyl acetate to obtain phosphorescent compound 5 (0.3 g). The compound was identified by elemental analysis, NMR and MASS spectrum.
The molecular core diameter, molecular core thickness and molecular radius of the phosphorescent compound 5 were calculated by performing structural optimization with Gaussian 03 (US Gaussian). As a result, the aspect ratio was 3.1, and the molecular radius was 1.93 nm.

(Synthesis Example 6)
<Synthesis of phosphorescent compound 6>

-Synthesis of Compound 6a-
p- (trans-4-pentylcyclohexyl) bromobenzene (manufactured by Tokyo Chemical Industry) (4 g), tri-t-butylphosphonium tetraphenylborate (manufactured by Kanto Chemical) (0.135 g), Pd (dba) ₂ (0.15 g) ), Lithium chloride (0.33 g) and zinc bis [bis (trimethylsilyl) amide] (manufactured by ALDRICH) (3 g) were reacted in a nitrogen atmosphere at 50 ° C. for 6 hours. Ethyl acetate was added to the reaction solution and poured into 1N aqueous hydrochloric acid. After neutralization with potassium carbonate, the solution was separated. After drying with magnesium sulfate, the mixture was concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1 / 3.5) to obtain Compound 6a (3.1 g).
-Synthesis of Compound 6b-
Compound 5e (1.0 g), Compound 6a (0.58 g), t-butoxy potassium (1.13 g), Pd (dba) ₂ (27 mg) and 2- (di-t-butylphosphino) biphenyl (Wako Pure) A toluene solution (10 ml) of (made by Yakuhin) (56.4 mg) was reacted at 110 ° C. for 6 hours under a nitrogen atmosphere. Ethyl acetate and water were added to the reaction solution, and after liquid separation, the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/9) to obtain Compound 6b (0.57 g).
-Synthesis of phosphorescent compound 6-
A benzonitrile solution (3 ml) of compound 6b (0.3 g) and PtCl ₂ (0.14 g) was reacted at 190 ° C. for 24 hours under a nitrogen atmosphere. After the reaction, benzonitrile was distilled off under reduced pressure, and the concentrated residue was purified by silica gel column chromatography (developing solvent: chloroform / hexane = 7/1). The obtained solid was washed with ethanol and then with ethyl acetate to obtain phosphorescent compound 6 (0.27 g). The compound was identified by elemental analysis, NMR and MASS spectrum.
The molecular core diameter, molecular core thickness, and molecular radius of the phosphorescent compound 6 were calculated by performing structural optimization with Gaussian 03 (US Gaussian Co., Ltd.). As a result, the aspect ratio was 3.1, and the molecular radius was 1.74 nm.

(Synthesis Example 7)
<Synthesis of discotic liquid crystalline material 1>

-Synthesis of Host 1a (host-1a)-
To a DME (dimethyl ether) solution (200 ml) of ethyl diethylphosphonoacetate (Wako Pure Chemical Industries, Ltd.) (20 ml) was added NaH (4.0 g) under ice cooling, and the mixture was stirred at room temperature for 10 minutes and then ice-cooled again. Below, a DME solution (60 ml) of decanal (manufactured by Wako Pure Chemical Industries, Ltd.) (18.9 ml) was added dropwise. After reacting at 80 ° C. for 3 hours, the reaction solution was poured into ethyl acetate / dilute hydrochloric acid (mixing ratio: ethyl acetate / dilute hydrochloric acid = 1/1), the organic layer was washed with brine, dried over magnesium sulfate, and then reduced in pressure. Concentrated with. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/30) to obtain host 1a (18.9 g).
-Synthesis of host 1b (host-1b)-
An aqueous solution (40 ml) of lithium hydroxide monohydrate (4.3 g) was added dropwise to a DME solution (100 ml) of host 1a (10.6 g), and reacted at 80 ° C. for 5 hours. The reaction solution was poured into ethyl acetate / dilute hydrochloric acid (mixing ratio: ethyl acetate / dilute hydrochloric acid = 1/1), and the organic layer was washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/3) and recrystallized from normal hexane to obtain host 1b (7.0 g).
-Synthesis of discotic liquid crystalline material 1-
Mesyl chloride (3.2 ml) was added dropwise at −15 ° C. to a THF solution (80 ml) of host 1b (8.6 g) and diisopropylethylamine (7.9 ml). After stirring for 1 hour, diisopropylethylamine (7.9 ml) was added to the reaction solution, and then a THF solution (80 ml) of 2,3,6,7,10,11-hexahydroxytriphenylene hydrate (2 g) was added dropwise. Then, a catalytic amount of dimethylaminopyridine was added and stirred at room temperature for 6 hours. The reaction solution was poured into ethyl acetate / dilute hydrochloric acid (mixing ratio: ethyl acetate / dilute hydrochloric acid = 1/1), and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue is purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/8) and recrystallized with ethanol / normal hexane = 95/5 to obtain discotic liquid crystalline host compound 1 (5.0 g). Got. The compound was identified by elemental analysis, NMR and MASS spectrum. The appearance was a white solid. As a result of calculating the molecular radius of the discotic liquid crystalline material 1 by performing structural optimization with Gaussian 03 (Gaussian, USA), the molecular radius was 1.80 nm. The aspect ratio was 9.1.
When the liquid crystal phase was observed using a polarizing microscope, the liquid crystal phase was shown in the following temperature range.
Cr 48 ° C Nd 79 ° C Iso
(Cr: crystal, Nd: discotic nematic phase, Iso: isotropic phase)
That is, the liquid crystal phase was developed in the temperature range of 48 to 79 ° C., and the phase transition temperature from the liquid crystal phase to the isotropic phase was 79 ° C.
(Synthesis Example 8)
<Synthesis of discotic liquid crystalline material 2>

-Synthesis of discotic liquid crystalline material 2-
Hexabromotriphenylene (1 g) and 4-octyloxyphenyl boric acid (3.2 g) in a xylene / water = 1/1 solution (20 ml / 20 ml) were mixed with Pd (PPh ₃ ) ₄ (0.17 g) and potassium carbonate ( 1.2 g), and the mixture was stirred at 120 ° C. for 12 hours under a nitrogen atmosphere. The reaction solution was poured into ethyl acetate / dilute hydrochloric acid (mixing ratio: ethyl acetate / dilute hydrochloric acid = 1/1), and the organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrated residue is purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/98) and recrystallized with ethanol / normal hexane = 95/5 to obtain discotic liquid crystalline host compound 2 (1.3 g). Got. The compound was identified by elemental analysis, NMR and MASS spectrum. The appearance was a white solid. As a result of calculating the molecular radius of the discotic liquid crystalline material 2 by performing structural optimization with Gaussian 03 (Gaussian, USA), the molecular radius was 1.89 nm. The aspect ratio was 3.1. When the liquid crystal phase was observed using a polarizing microscope, the liquid crystal phase was shown in the following temperature range.
Cr 70 ° C D 125 ° C Iso
(Cr: crystalline phase, D: discotic phase (detailed phase is unknown), Iso: isotropic phase)
That is, the liquid crystal phase was developed in the temperature range of 70 to 125 ° C., and the phase transition temperature from the liquid crystal phase to the isotropic phase was 125 ° C.

Example 1
<Production of substrate>
A quartz glass substrate of 25 mm × 25 mm × 0.7 mm was washed and treated with UV ozone, and then an alignment film (horizontal alignment film SE-130 manufactured by Nissan Chemical Industries) was applied by spin coating. By heating for 1 hour, a base substrate (alignment film thickness 200 nm) was obtained.
<Preparation of coating solutions 1-6>
A chloroform solution (coating solution) having a solid content of 2% by mass of discotic liquid crystalline material 1 (93 mg), phosphorescent compound 1 (7 mg) and fluorine atom-containing compound 1 (0.2 mg) represented by the following structural formula 1) was prepared.
Coating solutions 2 to 6 were prepared in the same manner as the coating solution 1 except that the phosphorescent compound 1 was changed to the phosphorescent compounds 2 to 6 in the coating solution 1.

<Preparation of coating solutions 7 and 8>
A coating solution 7 was prepared in the same manner as the coating solution 1 except that the discotic liquid crystalline material 1 was changed to the discotic liquid crystalline material 2 in the coating solution 1. Moreover, the coating liquid 8 was prepared like the coating liquid 5 except having changed the discotic liquid crystalline material 1 into the discotic liquid crystalline material 2 in the coating liquid 5. FIG.

<Preparation of coating liquid 9>
A coating solution 9 was prepared in the same manner as the coating solution 1 except that the phosphorescent compound 1 was changed to the phosphorescent compound 7 in the coating solution 1.

<Preparation of Samples 1-44>
Each of the light emitting layer forming coating solutions 1 to 9 was spin-coated (1500 rpm, 20 seconds) on a base substrate prepared in a nitrogen atmosphere. The substrate temperature at the time of spin coating was set to the temperature shown in Table 1. Thereafter, the substrate was vacuum dried at room temperature to obtain each sample.
The degree of orientation S of each sample was measured by the polarized ATR-IR method.
Evaluation of orientation was performed according to the following criteria.
○: Order degree S ≧ 0.6
Δ: degree of order 0.2 ≦ S <0.6
×: Order degree 0 ≦ S <0.2

  As shown in Table 1, when the substrate temperature is set to a temperature at which the liquid crystal phase of the liquid crystalline host material develops and a coating solution is applied to the substrate by spin coating to form a layer, the liquid crystalline host material is applied to the substrate in the layer. It can be seen that it is horizontally oriented.

(Example 2)
-Preparation of coating solution for forming light emitting layer-
MEK (methyl ethyl ketone) (99% by mass) is mixed with phosphorescent compound 1 (0.1% by mass) and discotic liquid crystalline material 1 (0.9% by mass) to obtain a coating solution 10 for forming a light emitting layer. It was.
The light emitting layer forming coating solutions 11 to 15 and 18 were prepared in the same manner as the light emitting layer forming coating solution 10 except that the phosphorescent compound 1 was changed to the phosphorescent compounds 2 to 7 in the light emitting layer forming coating solution 1. Prepared.
Further, in the light emitting layer forming coating solutions 10 and 14, the light emitting layer forming coating is performed in the same manner as the light emitting layer forming coating solutions 10 and 14, except that the discotic liquid crystalline material 1 is changed to the discotic liquid crystalline material 2. Liquids 16 and 17 were prepared, respectively.

<Production of organic electroluminescence device>
-Production of organic electroluminescent element 1-
A transparent support substrate was formed by depositing ITO to a thickness of 150 nm on a 25 mm × 25 mm × 0.7 mm glass substrate. This transparent support substrate was etched and washed.
On this ITO glass substrate, 2 parts by mass of PTPDES-2 (manufactured by Chemipro Kasei, Tg = 205 ° C.) represented by the following structural formula was dissolved in 98 parts by mass of cyclohexanone for electronics industry (manufactured by Kanto Chemical), and the thickness was about After spin coating (2,000 rpm, 20 seconds) to 40 nm, a hole injection layer was formed by drying at 120 ° C. for 30 minutes and annealing at 160 ° C. for 10 minutes.

On the hole injection layer, the light emitting layer forming coating solution 10 was spin coated (1,300 rpm, 30 seconds) so as to have a thickness of about 40 nm to obtain a light emitting layer. The substrate temperature at the time of spin coating was set to the temperature shown in Table 2.
Next, BAlq (bis- (2-methyl-8-quinolinolato) -4- (phenyl-phenolato) -aluminum (III)) represented by the following structural formula is formed on the light emitting layer as an electron transporting layer. It formed by the vacuum evaporation method so that it might become 40 nm.

On the electron transport layer, lithium fluoride (LiF) was formed as an electron injection layer by a vacuum deposition method so as to have a thickness of 1 nm. Furthermore, 70 nm of metal aluminum was vapor-deposited to make a cathode.
The laminate produced as described above is placed in a glove box substituted with argon gas, and sealed using a stainless steel sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). Thereby, the organic electroluminescent element 1 was produced.

-Production of organic electroluminescent elements 2-27-
Organic electroluminescent devices 2 to 27 were produced in the same manner as the organic electroluminescent device 1 except that the coating solution for forming the luminescent layer and the substrate temperature at the time of forming the luminescent layer were changed as shown in Table 2.

<Measurement of light extraction efficiency>
The organic electroluminescent element 1 was put into a PL quantum yield measuring apparatus manufactured by Hamamatsu Photonics, and excited at the main absorption wavelength of the phosphorescent compound, and the quantum yield (PL quantum efficiency) was measured. The organic electroluminescent elements 2 to 27 were similarly measured. The results are shown in Table 2. In addition, the result showed the thing apply | coated at room temperature among the elements obtained from the same light emitting layer coating liquid, and showed it by the relative value as 0.5.

<Element durability evaluation>
At an initial light emission luminance of 500 cd / m ² , a constant current was applied to the organic electroluminescent elements 1 to 18 at room temperature to continuously drive the device, and the time until the light emission luminance decreased to ½ was measured. Based on the measured values, the elements 1 to 3 were relatively evaluated with the luminance half-life of the element 1 being 1. For elements 4 to 6, elements 7 to 9, 10 to 12, 13 to 15, 16 to 18, 19 to 21, 22 to 24, and 25 to 27, the luminance half-life of the first element is set to 1 for relative evaluation. did. The results are shown in Table 2.

As can be seen from Table 2, the organic electroluminescent device of the present invention was superior in light extraction efficiency and device durability (luminance half-life) as compared with the organic electroluminescent device of the comparative example. Since the organic affinity and ionization potential of the organic electroluminescent devices made from the same coating solution are the same, the difference in device durability is that the transition dipole moment of the phosphorescent compound is oriented horizontally with respect to the anode. This is presumed to be due to an improvement in light extraction efficiency due to the above.
Since the organic electroluminescence device of the present invention has improved light extraction efficiency, it has high external quantum efficiency and excellent luminance stability over time.

DESCRIPTION OF SYMBOLS 2 ... Substrate 3 ... Anode 4 ... Hole injection layer 5 ... Hole transport layer 6 ... Light emitting layer 7 ... Hole block layer 8 ... Electron transport layer 9 ...・ Cathode 10: Organic electroluminescent device

Claims (11)

A method for producing an organic electroluminescent device having a light emitting layer including a light emitting material having an aspect ratio of 3 or more and a host material capable of exhibiting liquid crystallinity,
A method for manufacturing an organic electroluminescent element, wherein the light emitting layer is applied and formed in a temperature range in which the host material exhibits liquid crystallinity.   2. The temperature range in coating and forming the light emitting layer is a temperature higher than 40 ° C. and a temperature lower by 5 ° C. or more than a phase transition temperature from a liquid crystal phase to an isotropic phase of the host material. A method for producing an organic electroluminescent element.   The method for producing an organic electroluminescent element according to claim 1, wherein an aspect ratio of the host material is 3 or more.   The manufacturing method of the organic electroluminescent element of any one of Claims 1-3 whose said host material is a discotic liquid crystalline material.   The manufacturing method of the organic electroluminescent element of Claim 4 with which the said discotic liquid crystalline material expresses a discotic nematic liquid crystal phase.   The manufacturing method of the organic electroluminescent element of any one of Claims 1-5 whose said luminescent material is a phosphorescent luminescent material.   The method for producing an organic electroluminescent element according to claim 6, wherein the phosphorescent material is a platinum complex. The method for producing an organic electroluminescent element according to claim 6 or 7, wherein the phosphorescent material is at least one selected from phosphorescent compounds represented by the following general formulas (1) to (5).
General formula (1)

(In the general formula (1), X, Y, and Z represent a carbon atom or a nitrogen atom, and one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. M, n, p and q each independently represents an integer of 0 to 3. Ar represents an aryl group, and R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group or an aryloxy group. Group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and q are 2 or more, a plurality of R _{1 to} R ₄ are connected to each other to form a cyclic structure. It may be formed.)
General formula (2)

(In General Formula (2), X, Y, and Z represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. R, s, t and u each independently represents an integer of 0 to 3. R _{5 to} R ₈ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group. , A silyl group, or a heterocyclic group, and when r, s, t, and u are 2 or more, a plurality of R _{5 to} R ₈ may be connected to each other to form a cyclic structure. ₁ and W ₂ represent an alkyl group and may be bonded to each other to form a cyclic structure.
General formula (3)

(In General Formula (3), R _{9 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ may combine with each other to form a cyclic structure.)
General formula (4)

(In General Formula (4), X, Y, and Z represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. M, n, p and g each independently represents an integer of 0 to _3. Ar represents an aryl group, R _{1 to} R ₃ and R ₃₀ , each independently an alkyl group, an aryl group, an alkoxy group, An aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and g are 2 or more, a plurality of R _{1 to} R ₃ and R ₃₀ are connected to each other adjacent to each other. A cyclic structure may be formed, and M and Q are each independently a carbon atom or a nitrogen atom.)
General formula (5)

(In General Formula (5), Z represents a carbon atom or a nitrogen atom. M, n, and g each independently represents an integer of 0 to _3. Ar represents an aryl group. R ₁ , R _2, and R ₃₀ independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, or g is 2 or more, a plurality of R ₁ , R ₂ and R ₃₀ may be linked to each other to form a cyclic structure, and M and Q are each independently a carbon atom or a nitrogen atom.)   The organic electroluminescent device having the light emitting layer between an anode and a cathode, wherein the transition dipole moment of the phosphorescent material is oriented horizontally with respect to the anode. The manufacturing method of the organic electroluminescent element of any one of 6-8.   The manufacturing method of the organic electroluminescent element of any one of Claims 1-9 in which the said light emitting layer contains 0.0001 mass%-10 mass% of fluorine atom containing compounds.   The organic electroluminescent element produced by the production method of any one of Claims 1-10.

Images