JP6105299B2 - Composition for organic electroluminescence device and organic electroluminescence device - Google Patents

Description

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

The organic electroluminescent element is a self-luminous element that emits surface light. When used as a lighting device, it can reduce power consumption and contribute to energy saving compared to incandescent and fluorescent lamps that are currently mainstream. This element is expected to be used as next-generation lighting. In addition, the element itself is very thin, light, flexible, and flexible. Practical use is expected as an excellent lighting device.

An organic electroluminescent element has a structure in which one or more layers including a light emitting layer formed by containing a luminescent organic compound are sandwiched between an anode and a cathode, and is injected from holes and cathodes injected from the anode. The emitted electrons excite the light-emitting organic compound using energy when recombining to obtain light emission. The most basic organic electroluminescent device has a structure in which a light emitting layer is sandwiched between an anode and a cathode, but it is necessary to improve performance such as lower drive voltage and longer life. Depending on the case, a hole injection layer, a hole transport layer, an electron blocking layer, an interlayer, a hole blocking layer, an electron transport layer, an electron injection layer may be provided, and two or more charge generation layers may be provided. A multi-photon emission type organic electroluminescence device in which an organic electroluminescence device structure is built up is also proposed.

There are two types of film forming methods for forming the organic compound layer, vapor deposition and coating. In many of the organic electroluminescent devices that are currently commercialized, an organic compound layer is formed by vapor deposition. Since vapor deposition can be easily multi-layered, functional separation is achieved by layers to achieve high efficiency and long life. On the other hand, in order to produce an organic electroluminescent element by vapor deposition, a large-scale manufacturing apparatus for continuously vapor-depositing a plurality of organic compounds is required, and it is considered that enormous initial investment is required.
On the other hand, film formation by coating does not require a large-scale manufacturing apparatus and can be manufactured by roll-to-roll, and is advantageous for increasing the screen from the viewpoint of manufacturing cost and processing time. Depending on the type, there is a problem that the lower layer dissolves when the upper layer is applied, and there is a problem that it is difficult to increase the number of layers for lowering the driving voltage and extending the life. As an example, in the case of an organic electroluminescent device having a forward structure in which an organic compound layer and a cathode are laminated on an anode formed on a substrate, a solution containing an organic solvent is applied on the light emitting layer to apply electrons. When the transport layer and the electron injection layer are formed, the light emitting layer is dissolved. Therefore, it is difficult to form the layer on the light emitting layer by applying a solution containing an organic solvent.
As a method for producing a very general coating type organic electroluminescence device, for example, poly (3,4-ethylenedioxythiophene / styrenesulfonic acid) is formed on an anode made of ITO (indium tin oxide) formed on a substrate. ) (PEDOT / PSS) hole injection / hole transport layer (buffer layer) formed by coating from an aqueous dispersion, poly (dioctylfluorene-alt-N- (4-butylphenyl) diphenylamine) (TFB) ) Is formed by application from a toluene solution, followed by insolubilization treatment (which is thought to be caused by a crosslinking reaction, etc.) by heating, and further a light emitting layer made of poly (dioctylfluorene) or the like is formed from a toluene solution. After forming, the cathode is lithium fluoride (LiF) / calcium (Ca) / aluminum (Al). How to film at empty deposition and the like (Non-Patent Document 1).
As described above, since the organic compound layer forming the light emitting layer often uses a compound soluble in a nonpolar solvent such as toluene or xylene, it is very difficult to form an organic compound layer between the light emitting layer and the cathode. There were few examples.

Among these, several organic electroluminescent devices have been proposed in which a layer is formed by applying an organic compound-containing solution between the light emitting layer and the cathode, and a layer made of polyethyleneimine or polyethylene glycol is included therein. An organic electroluminescent device in which is formed has been reported (see Non-Patent Documents 2 and 3). Since polyethyleneimine or polyethylene glycol can be dissolved in water or a lower alcohol solvent, if a layer is formed using polyethyleneimine or polyethylene glycol dissolved in water or a lower alcohol solvent, water or It is possible to form a layer by coating on a layer (eg, a light emitting layer) formed of a compound that is not soluble in a lower alcohol solvent.

Stelios A. Choulis et al. , Advanced Functional Materials, Vol. 16, 1075 (2006) Yinhua Zhuo et al. , Science, Vol. 336, 327 (2012) Tzung-Fang Guo et al. , Applied Physics Letters, Vol. 87,013504 (2005)

As described above, it has been proposed to use polyethyleneimine or polyethylene glycol as the material of the layer constituting the organic electroluminescent element, and if these are used, the layer is formed of a compound that does not dissolve in water or a lower alcohol solvent. It is possible to form a layer on it without dissolving it. However, when a layer is formed by coating using polyethyleneimine or polyethylene glycol, there are the following problems. That is, in general, it is difficult to obtain reproducibility and uniformity when attempting to reduce the film thickness of the organic compound layer. However, since polyethyleneimine and polyethylene glycol are insulators, there is a problem that when the film thickness is increased, the resistance increases and the drive voltage of the organic electroluminescent element increases.

The present invention has been made in view of the above situation, and can be applied without dissolving the lower layer when forming the organic compound layer, and can suppress an increase in the driving voltage of the organic electroluminescent element. It is an object of the present invention to provide a possible composition for an organic electroluminescent element and an organic electroluminescent element formed using the composition for an organic electroluminescent element.

The inventors of the present invention have made various studies on methods that can form an organic compound layer by coating without dissolving the lower layer, and can also suppress an increase in driving voltage of the obtained organic electroluminescent element. A material for forming a layer of an organic electroluminescence device comprising a composition comprising a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton, and a π-electron conjugated compound soluble in water or a lower alcohol Then, when forming a layer by coating, it is found that the layer can be formed without dissolving the lower layer, and the increase in the driving voltage of the obtained organic electroluminescent element can be suppressed. The invention has been reached.

That is, the present invention relates to a composition used for forming an organic electroluminescence device having a structure in which a plurality of layers are laminated between a cathode and an anode formed on a substrate. An organic electroluminescent element composition comprising a polymer having an alkylene oxide structure and / or a polyalkyleneimine structure in a main chain skeleton, and a π-electron conjugated compound soluble in water or a lower alcohol. .
This invention is also an organic electroluminescent element formed using the said composition for organic electroluminescent elements.
The present invention is described in detail below.
A combination of two or more preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

The composition for organic electroluminescent elements of the present invention comprises a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton, and a π-electron conjugated compound soluble in water or a lower alcohol. . A layer formed from the composition for organic electroluminescence device of the present invention by adding a highly conductive π electron conjugated compound to a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton. The electrical conductivity of can be improved. As a result, even when the thickness of the organic compound layer is increased, an increase in driving voltage of the organic electroluminescent element can be suppressed.
The composition for organic electroluminescent elements of the present invention comprises a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton, and one π-electron conjugated compound soluble in water or lower alcohol, respectively. It may be a thing and 2 or more types may be included. Further, as long as it contains a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton and a π-electron conjugated compound soluble in water or a lower alcohol, it may contain other components. Good.

The polyalkylene oxide structure of the polymer having the polyalkylene oxide structure in the main chain skeleton is preferably a structure formed of an alkylene oxide having 2 to 4 carbon atoms. A polymer having a structure formed of an alkylene oxide having such a carbon number is easily soluble in water or a lower alcohol and is available at low cost. More preferably, it is a structure formed of an alkylene oxide having 2 or 3 carbon atoms.
The polyalkyleneimine structure of the polymer having the polyalkyleneimine structure in the main chain skeleton is preferably a structure formed of an alkyleneimine having 2 to 4 carbon atoms. A polymer having a structure formed of such an alkyleneimine having a carbon number is easily soluble in water or a lower alcohol and is available at a low cost. More preferably, it is a structure formed by alkyleneimine having 2 or 3 carbon atoms.

The polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton may be any polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton. It may be a copolymer having a structure other than an alkylene oxide structure and / or a polyalkyleneimine structure.

When the polymer having the polyalkylene oxide structure and / or polyalkyleneimine structure in the main chain skeleton has a structure other than the polyalkylene oxide structure and / or the polyalkyleneimine structure, the polyalkylene oxide structure and / or the polyalkyleneimine structure Examples of the monomer that is a raw material having a structure other than that include ethylene, propylene, butene, acetylene, acrylic acid, styrene, and vinyl carbazole, and one or more of these can be used. . Moreover, the thing of the structure where the hydrogen atom couple | bonded with the carbon atom of these monomers was substituted by the other organic group can also be used suitably. Examples of the other organic group substituted with a hydrogen atom include a hydrocarbon group having 1 to 10 carbon atoms that may contain at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom. Is mentioned.

The polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton is composed of a polyalkylene oxide structure and / or a polyalkylene out of 100% by mass of the monomer component forming the main chain skeleton of the polymer. The monomer that forms an imine structure is preferably 30% by mass or more. More preferably, it is 50 mass% or more, More preferably, it is 80 mass% or more. Most preferably, the amount of the monomer forming the polyalkylene oxide structure and / or polyalkyleneimine structure is 100% by mass, that is, the polymer having the polyalkylene oxide structure and / or polyalkyleneimine structure in the main chain skeleton. Is a homopolymer of polyalkylene oxide and / or polyalkyleneimine.

The polymer having the polyalkylene oxide structure and / or polyalkyleneimine structure in the main chain skeleton preferably has a weight average molecular weight of 100 to 80,000. More preferably, it is 200-20,000, More preferably, it is 500-10,000.
The weight average molecular weight can be determined by GPC (gel permeation chromatography) measurement under the following conditions.
Measuring instrument: Waters Alliance (2695) (trade name, manufactured by Waters)
Molecular weight column: TSKguard column α, TSKgel α-3000, TSKgel α-4000, TSKgel α-5000 (all manufactured by Tosoh Corporation) are connected in series. Eluent: 100 mM boric acid aqueous solution 14304 g and 50 mM sodium hydroxide aqueous solution 96 g Standard material for solvent calibration curve mixed with 3600 g of acetonitrile and polyethylene glycol (manufactured by Tosoh Corporation)
Measurement method: The molecular weight is measured by dissolving the object to be measured in the eluent so that the solid content is about 0.2% by mass, and using the product filtered through a filter as the measurement sample.

Examples of the π-electron conjugated compound are not particularly limited as long as they are π-electron conjugated compounds soluble in water or lower alcohol, but benzene ring, pyridine ring, imidazole ring, thiophene ring, oxazole ring, thiazole ring, A low molecular compound or a high molecular compound containing a triazole ring, a thiadiazole ring, or the like, or a π-conjugated unit in which these are further condensed is preferable.
Specifically, the π-electron conjugated compound is represented by the following general formula (1), (2) or (3);

(Wherein R ¹ is the same or different and represents an aryl group, aryloxy group, heteroaryl group, or heteroaryloxy group which may have a substituent. R ² is the same or different. And represents a hydrogen atom or a monovalent organic group, n represents the number of benzene rings bonded to the phosphorus atom, and is an integer of 1 to 3.)

(In the formula, R ³ is the same or different and represents a hydrogen atom or a monovalent organic group. When there are a plurality of monovalent organic groups represented by R ³ , some of the plurality of organic groups. Alternatively, all may be bonded to form an aromatic ring or an aromatic heterocyclic ring together with a part of the aromatic heterocyclic ring containing N. A part of the plurality of organic groups may be bonded to form an aromatic ring or aromatic ring. In the case where a heterocyclic group is formed, the remaining organic group may be bonded to an aromatic ring or an aromatic heterocyclic ring formed from a part of the plurality of organic groups, or an aromatic group containing N. It may be bonded to a heterocyclic group. M represents the number of R ³ bonded to the aromatic heterocyclic ring containing N, and is an integer of 1 to ^3. )

(In the formula, R ⁴ and R ⁵ are the same or different and represent a hydrogen atom or a monovalent organic group. X ¹ and X ² are the same or different and represent a carbon atom, a nitrogen atom or an oxygen atom. The bond portion that connects the carbon atom to which X ¹ and R ⁴ are bonded, and the dotted line portion in the bond portion that connects the carbon atom to which X ² and R ⁴ are bonded are double X ¹ or X ² and the carbon atom. It is preferably any of the compounds represented by the above).

When R ² in the general formula (1) is a monovalent organic group, examples of the monovalent organic group include a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, and an amino group. , Cyano group, fluoro group, chloro group and the like. As a hydrocarbon group, any of a C1-C6 alkyl group, an alkenyl group, and an alkynyl group is preferable.
When the aryl group, aryloxy group, heteroaryl group, or heteroaryloxy group in R ¹ of the general formula (1) has a substituent, the substituent is a hydrocarbon having 1 to 6 carbon atoms. Group, a C1-C6 alkoxy group, a hydroxyl group, an amino group, a cyano group, a fluoro group, and a chloro group.

In the above general formula (2), when R ³ is a monovalent organic group and does not form an aromatic ring or an aromatic heterocycle, the monovalent organic group includes a hydrocarbon group having 1 to 6 carbon atoms, Examples thereof include an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, an amino group, a cyano group, a fluoro group, and a chloro group. Examples of the hydrocarbon group, those R ² in the general formula (1) is similar to the case of the hydrocarbon group is preferred.
There are a plurality of monovalent organic groups represented by R ³ , and some or all of the plurality of organic groups are bonded together with a part of the aromatic heterocyclic ring containing N, or an aromatic ring or an aromatic heterocyclic ring In the case of forming an aromatic ring, examples of the aromatic ring or aromatic heterocyclic ring include aromatic rings such as a benzene ring, a naphthalene ring, and an anthracene ring; and heterocyclic rings such as a pyridine ring, a quinoline ring, and an isoquinoline ring. Among these, a benzene ring, a naphthalene ring, or a quinoline ring is preferable.
That is, in the structure represented by the general formula (2), there are a plurality of monovalent organic groups represented by R ³ , and the plurality of organic groups are combined to form an aromatic heterocyclic ring containing N. A preferred structure in the case where an aromatic ring or an aromatic heterocycle is formed together with a part of is a structure of any one of the following general formulas (2-1) to (2-3).

(Wherein, ^{R 3} is .m ¹ and ^{m 2} is the same as in the general formula (2) are the same or different, represents the number of ^{R 3} of bonding to the ring structure, an integer of 0 to 2. )

(In the formula, R ³ is the same as in the general formula (2). M ¹ , m ² and m ³ are the same or different and represent the number of R ³ bonded to the ring structure, and an integer of 0 to 2) .)

(In the formula, R ³ is the same as in the general formula (2). M ¹ , m ² and m ³ are the same or different and represent the number of R ³ bonded to the ring structure, and an integer of 0 to 2) .)

In the above general formula (3), X ¹ and X ² are the same or different and represent a carbon atom, a nitrogen atom or an oxygen atom, but X ¹ and X ² are both nitrogen atoms, or X ¹ is carbon. an atom, or X ² is an oxygen atom, X ¹ is an oxygen atom, or X ² is a carbon atom, X ¹ is an oxygen atom, it is preferred that X ² is a nitrogen atom. When X ¹ and X ² are both nitrogen atoms, the 5-membered ring to which R ⁴ and R ⁵ are bonded is a triazole ring, and when X ¹ is a carbon atom and X ² is an oxygen atom , R ⁴ , and R ⁵ bonded to each other are an isoxazole ring, when X ¹ is an oxygen atom, and when X ² is a carbon atom, it is an oxazole ring, and X ¹ is an oxygen atom. When X ² is a nitrogen atom, it becomes an oxadiazole ring.
R ⁴ and R ⁵ are the same or different and represent a hydrogen atom or a monovalent organic group, and examples of the monovalent organic group include an alkyl group having 1 to 6 carbon atoms and an alkylamino group having 1 to 6 carbon atoms. And amino groups. R ⁴ is preferably an alkyl group having 1 to 6 carbon atoms, an amino group, or an alkylamino group having 1 to 6 carbon atoms. R ⁵ is preferably a hydrogen atom or an amino group.

As the π-electron conjugated compound represented by the general formula (1), a phosphine oxide compound such as diphenylphosphine oxide, diphenylmethylphosphine oxide or triphenylphosphine oxide is preferable.
Examples of the π-electron conjugated compound represented by the general formula (2) include pyridine compounds such as dimethylpyridine, aminopyridine, and cyanopyridine, pyridine condensed ring compounds such as aminoquinoline, benzoquinoline, and phenanthroline, and poly (vinyl). High molecular compounds such as pyridine) are preferred.
As the π-electron conjugated compound represented by the general formula (3), a heterocyclic compound such as aminomethylisoxazole or diaminotriazole is preferable.
More preferred is triphenylphosphine oxide, 3-cyanopyridine, 4-cyanopyridine, 1,10-phenanthroline, or poly (4-vinylpyridine), and even more preferred is triphenylphosphine oxide or poly (4 -Vinylpyridine).

The preferred concentration of the polymer having a polyalkylene oxide structure and / or polyalkyleneimine structure in the main chain skeleton and the π-electron conjugated compound soluble in water or lower alcohol in the composition for organic electroluminescence device of the present invention is organic. The polyalkylene oxide structure and / or polyalkyleneimine in 100% by mass of the composition for organic electroluminescent elements of the present invention varies depending on the coating method and conditions for forming the layer by coating the composition for electroluminescent elements. The concentration of the polymer having a structure in the main chain skeleton is preferably 0.1 to 10% by mass.
Moreover, it is preferable that the density | concentration of the (pi) electron conjugated compound soluble in water or a lower alcohol in the composition for organic electroluminescent elements of this invention is 0.02-2 mass%.
The organic electroluminescent device composition of the present invention comprises a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton, and a π-electron conjugated compound soluble in water or a lower alcohol. It is preferable to contain in each preferable ratio. In such a preferable ratio, the concentration may be appropriately set according to the coating method and conditions.
In addition, the composition for organic electroluminescent elements here means the whole composition containing a solvent in addition to the solid content in the composition.

The polymer having the polyalkylene oxide structure and / or the polyalkyleneimine structure in the main chain skeleton is soluble in water or a lower alcohol. As the π electron conjugated compound, those soluble in water or lower alcohol are used. Thereby, water or a lower alcohol can be used as a solvent which the composition for organic electroluminescent elements of this invention contains.
If water or a lower alcohol is used as the solvent contained in the composition for organic electroluminescent elements of the present invention, a layer formed by coating is formed thereon without dissolving the layer formed by the compound that does not dissolve in water or the lower alcohol. It is possible.
It does not specifically limit as said lower alcohol, A C1-C8 alcohol is preferable, More preferably, it is a C1-C3 alcohol.
As the lower alcohol, methanol, ethanol, 1-propanol, or 2-propanol can be suitably used, and among these, methanol or ethanol is more preferable.

The amount of the solvent is a π-electron conjugated system soluble in a polymer, water, or lower alcohol having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton in the composition for organic electroluminescent elements of the present invention. What is necessary is just to set suitably the density | concentration of a compound so that it may become a suitable density | concentration according to the application method and conditions of the composition.

The composition for organic electroluminescent elements of the present invention is used for forming an organic electroluminescent element having a structure in which a plurality of layers are laminated between a cathode and an anode formed on a substrate.
Hereinafter, the organic electroluminescence device will be described in detail.
Such an organic electroluminescent element formed using the composition for an organic electroluminescent element of the present invention is also one aspect of the present invention.

The organic electroluminescent element of the present invention is an element having a forward structure in which a plurality of layers are laminated between a cathode and an anode formed on a substrate, and each layer laminated between the cathode and the anode is It is mainly formed of an organic compound or an organometallic compound.
Of the layers stacked between the cathode and the anode, one layer is a light emitting layer, and has an electron injection layer and, if necessary, an electron transport layer between the cathode and the light emitting layer, and emits light from the anode. An element having a hole transport layer and / or a hole injection layer between the layers is preferable. Moreover, the organic electroluminescent element of this invention may have another layer between these each layer, However, It is preferable that it is an element comprised only from these each layer. That is, an element in which an anode, a hole injection layer and / or a hole transport layer, a light emitting layer, and if necessary, an electron transport layer, an electron injection layer, and a cathode are stacked adjacently in this order on a substrate. Is preferred. Each of these layers may be composed of one layer, or may be composed of two or more layers.
In the organic electric field element having the above configuration, when the element does not have an electron transport layer, the electron injection layer and the light emitting layer are adjacent to each other. When the device has only one of a hole transport layer and a hole injection layer, the one layer is stacked adjacent to the light emitting layer and the anode, and the device transports the hole. When both the layer and the hole injection layer are provided, these layers are laminated adjacently in the order of the anode, the hole injection layer, the hole transport layer, and the light emitting layer.

The composition for organic electroluminescent elements of the present invention is preferably used for forming an electron injection layer. When an electron injection layer is formed using the composition for organic electroluminescent elements of the present invention, even when a light emitting layer or an electron transport layer is formed by applying a material dissolved in an organic solvent, a lower light emitting layer or an electron transport layer is formed. It becomes possible to apply and form the electron transport layer on the substrate without dissolving it.

The average thickness of the electron injection layer using the composition for organic electroluminescent elements of the present invention is preferably 1 to 30 nm. More preferably, it is 1 to 10 nm.
The average thickness of the electron injection layer can be measured by a stylus profilometer or spectroscopic ellipsometry.

Use of the composition for organic electroluminescent elements of the present invention as an electron transporting layer is one of the preferred embodiments of the present invention. When forming an electron carrying layer using the composition for organic electroluminescent elements of this invention of this invention, an electron injection layer will be provided separately. As a compound that can be used separately as an electron injection layer, lithium fluoride, cesium fluoride, lithium carbonate, cesium carbonate, or the like can be given.

In the organic electroluminescent element of the present invention, as a material for forming the light emitting layer, any compound that can be usually used as the material of the light emitting layer can be used, whether it is a low molecular compound or a high molecular compound. It is also possible to use a mixture of these.
In the present invention, the low molecular weight material means a material that is not a polymer material (polymer), and does not necessarily mean an organic compound having a low molecular weight.

Examples of the polymer material forming the light emitting layer include polyacetylene compounds such as trans-type polyacetylene, cis-type polyacetylene, poly (di-phenylacetylene) (PDPA), and poly (alkylphenylacetylene) (PAPA); (Para-phenvinylene) (PPV), poly (2,5-dialkoxy-para-phenylenevinylene) (RO-PPV), cyano-substituted-poly (para-phenvinylene) (CN-PPV), poly (2 Polyparaphenylene vinylene compounds such as -dimethyloctylsilyl-para-phenylene vinylene (DMOS-PPV), poly (2-methoxy-5- (2'-ethylhexoxy) -para-phenylene vinylene) (MEH-PPV) Poly (3-alkylthiophene) (PAT), poly (oxy Polythiophene compounds such as (Lopylene) triol (POP); poly (9,9-dialkylfluorene) (PDAF), poly (dioctylfluorene-alt-benzothiadiazole) (F8BT), α, ω-bis [N, N ′ -Di (methylphenyl) aminophenyl] -poly [9,9-bis (2-ethylhexyl) fluorene-2,7-zyl] (PF2 / 6am4), poly (9,9-dioctyl-2,7-divinylene) Polyfluorene-based compounds such as fluorenyl-ortho-co (anthracene-9,10-diyl); poly (para-phenylene) (PPP), poly (1,5-dialkoxy-para-phenylene) (RO— Polyparaphenylene compounds such as PPP); polycarbazol such as poly (N-vinylcarbazole) (PVK) Polysilane compounds such as poly (methylphenylsilane) (PMPS), poly (naphthylphenylsilane) (PNPS), poly (biphenylylphenylsilane) (PBPS); and Japanese Patent Application No. 2010-230995, Examples thereof include boron compound-based polymer materials described in Japanese Patent Application No. 2011-6457.

Examples of the low molecular weight material forming the light emitting layer include a tricoordinate iridium complex having 2,2′-bipyridine-4,4′-dicarboxylic acid as a ligand, and factory (2-phenylpyridine). Iridium (Ir (ppy) ₃ ), 8-hydroxyquinoline aluminum (Alq ₃ ), tris (4-methyl-8 quinolinolate) aluminum (III) (Almq ₃ ), 8-hydroxyquinoline zinc (Znq ₂ ), (1, 10-phenanthroline) -tris- (4,4,4-trifluoro-1- (2-thienyl) -butane-1,3-dionate) europium (III) (Eu (TTA) ₃ (phen)), 2, Various metal complexes such as 3,7,8,12,13,17,18-octaethyl-21H, 23H-porphine platinum (II); Benzene compounds such as zen (DSB) and diamino distyryl benzene (DADSB); naphthalene compounds such as naphthalene and nile red; phenanthrene compounds such as phenanthrene; chrysene compounds such as chrysene and 6-nitrochrysene A perylene compound such as perylene, N, N′-bis (2,5-di-t-butylphenyl) -3,4,9,10-perylene-di-carboximide (BPPC); Coronene compounds; anthracene compounds such as anthracene and bisstyrylanthracene; pyrene compounds such as pyrene; 4- (di-cyanomethylene) -2-methyl-6- (para-dimethylaminostyryl) -4H-pyran (DCM) pyran compounds; acridine compounds such as acridine Compound; stilbene compound such as stilbene; thiophene compound such as 2,5-dibenzoxazole thiophene; benzoxazole compound such as benzoxazole; benzimidazole compound such as benzimidazole; 2,2′- Benzothiazole compounds such as (para-phenylenedivinylene) -bisbenzothiazole; butadiene compounds such as bistyryl (1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene; naphthalimides such as naphthalimide Phthalimide compounds; coumarin compounds such as coumarin; perinone compounds such as perinone; oxadiazole compounds such as oxadiazole; aldazine compounds; 1,2,3,4,5-pentaphenyl-1 , 3-Cyclopentadiene Cyclopentadiene compounds such as PPCP); quinacridone compounds such as quinacridone and quinacridone red; pyridine compounds such as pyrrolopyridine and thiadiazolopyridine; 2,2 ′, 7,7′-tetraphenyl-9, Spiro compounds such as 9′-spirobifluorene; metal or metal-free phthalocyanine compounds such as phthalocyanine (H ₂ Pc) and copper phthalocyanine; and JP 2009-155325 A and JP 2011-184430 A And boron compound materials described in Japanese Patent Application No. 2011-6458.

Although the average thickness of the said light emitting layer is not specifically limited, It is preferable that it is 10-150 nm. More preferably, it is 20-100 nm.
The average thickness of the light emitting layer can be measured by a stylus profilometer or spectroscopic ellipsometry. When the light emitting layer is formed by a vacuum deposition method, it can be measured at the time of film formation by a quartz oscillator film thickness meter.

In the organic electroluminescent device of the present invention, the electron injection layer is preferably formed directly on the light emitting layer, but an electron transport layer may be formed between the light emitting layer and the electron injection layer. When the electron transport layer is formed, as the material, any compound that can be normally used as the material of the electron transport layer can be used, and these compounds may be mixed and used.
Examples of compounds that can be used as the material for the electron transport layer include pyridine derivatives such as tris-1,3,5- (3 ′-(pyridin-3 ″ -yl) phenyl) benzene (TmPyPhB), ( Quinoline derivatives such as 2- (3- (9-carbazolyl) phenyl) quinoline (mCQ)), pyrimidine derivatives such as 2-phenyl-4,6-bis (3,5-dipyridylphenyl) pyrimidine (BPyPPM), Pyrazine derivatives, phenanthroline derivatives such as bathophenanthroline (BPhen), 2,4-bis (4-biphenyl) -6- (4 ′-(2-pyridinyl) -4-biphenyl)-[1,3,5] triazine Triazine derivatives such as (MPT), 3-phenyl-4- (1′-naphthyl) -5-phenyl-1,2,4-triazole (T A triazole derivative such as Z), an oxazole derivative, an oxadiazole derivative such as 2- (4-biphenylyl) -5- (4-tert-butylphenyl-1,3,4-oxadiazole) (PBD), Imidazole derivatives such as 2,2 ′, 2 ″-(1,3,5-bentriyl) -tris (1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring tetracarboxylic such as naphthalene and perylene Various metal complexes represented by acid anhydride, bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (Zn (BTZ) ₂ ), tris (8-hydroxyquinolinato) aluminum (Alq3), 2,5- Shiro such as bis (6 ′-(2 ′, 2 ″ -bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy) An organosilane derivative represented by a ruthenium derivative can be used, and one or more of these can be used.
Among these, a metal complex such as Alq ₃ and a pyridine derivative such as TmPyPhB are preferable.

When the organic electroluminescent element of the present invention has a hole transport layer, various p-type high molecular materials and various p-type low molecular materials are used alone as the hole transport organic material used as the hole transport layer. Or they can be used in combination.
Examples of the p-type polymer material (organic polymer) include polyarylamines, fluorene-arylamine copolymers, fluorene-bithiophene copolymers, poly (N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, Examples thereof include polyalkylthiophene, polyhexylthiophene, poly (p-phenylene vinylene), polytinylene vinylene, pyrene formaldehyde resin, ethylcarbazole formaldehyde resin, and derivatives thereof.
These compounds can also be used as a mixture with other compounds. As an example, the polythiophene-containing mixture includes poly (3,4-ethylenedioxythiophene / styrene sulfonic acid) (PEDOT / PSS).

Examples of the p-type low molecular weight material include 1,1-bis (4-di-para-triaminophenyl) cyclohexane, 1,1′-bis (4-di-para-tolylaminophenyl)- Arylcycloalkane compounds such as 4-phenyl-cyclohexane; 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′, N′-tetraphenyl-1,1′-biphenyl-4, 4′-diamine, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine (TPD1), N, N′-diphenyl-N , N′-bis (4-methoxyphenyl) -1,1′-biphenyl-4,4′-diamine (TPD2), N, N, N ′, N′-tetrakis (4-methoxyphenyl) -1,1 '-Biphenyl-4,4'-diamine (TPD3), N N′-di (1-naphthyl) -N, N′-diphenyl-1,1′-biphenyl-4,4′-diamine (α-NPD), arylamine compounds such as TPTE; N, N, N ', N'-tetraphenyl-para-phenylenediamine, N, N, N', N'-tetra (para-tolyl) -para-phenylenediamine, N, N, N ', N'-tetra (meta-tolyl) ) -Phenylenediamine compounds such as meta-phenylenediamine (PDA); Carbazole compounds such as carbazole, N-isopropylcarbazole, and N-phenylcarbazole; Stilbenes such as stilbene and 4-di-para-tolylaminostilbene system compound; oxazole-based compounds such as _{O x} Z; triphenylmethane, triphenylmethane compounds such as m-MTDATA; 1-full Pyrazoline compounds such as nil-3- (para-dimethylaminophenyl) pyrazoline; benzine (cyclohexadiene) compounds, triazole compounds such as triazole; imidazole compounds such as imidazole, 1,3,4-oxa Oxadiazole compounds such as diazole, 2,5-di (4-dimethylaminophenyl) -1,3,4, -oxadiazole; anthracene, anthracene such as 9- (4-diethylaminostyryl) anthracene Fluorenone, 2,4,7, -trinitro-9-fluorenone, fluorenone such as 2,7-bis (2-hydroxy-3- (2-chlorophenylcarbamoyl) -1-naphthylazo) fluorenone; polyaniline Aniline compounds such as silane Compound; 1,4-dithioketo-3,6-diphenyl-pyrrolo- (3,4-c) pyrrolopyrrole compound such as pyrrolopyrrole; fluorene compound such as fluorene; porphyrin, such as metal tetraphenylporphyrin Porphyrin compounds; quinacridone compounds such as quinacridone; metal or metal-free phthalocyanine compounds such as phthalocyanine, copper phthalocyanine, tetra (t-butyl) copper phthalocyanine, iron phthalocyanine; copper naphthalocyanine, vanadyl naphthalocyanine, monochlorogallium Metallic or metal-free naphthalocyanine compounds such as naphthalocyanine; N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine, N, N, N ′, N′-tetraphenyl Benzidine like benzidine Thing, and the like.

When the organic electroluminescent element of the present invention has an electron transport layer or a hole transport layer, the average thickness of these layers is not particularly limited, but is preferably 10 to 150 nm. More preferably, it is 20-100 nm.
The average thicknesses of the electron transport layer and the hole transport layer can be measured by a stylus profilometer or spectroscopic ellipsometry. When each layer is formed by a vacuum deposition method, it can be measured at the time of film formation by a quartz oscillator film thickness meter.

When the organic electroluminescent device of the present invention has a hole injection layer, any organic compound that can be usually used as a material for the hole injection layer can be used as a material thereof. Also good.
Examples of the organic compound that can be used as the material for the hole injection layer include the compounds mentioned as the material for the hole transport layer, and one or more of these can be used.

In the organic electroluminescence device of the present invention, the anode formed on the substrate contains ITO (indium tin oxide), IZO (indium zinc oxide), FTO (fluorine tin oxide), In ₃ O ₃ , SnO ₂ , and Sb. Examples thereof include oxides such as SnO ₂ and Al-containing ZnO. Among these, ITO, IZO, and FTO are preferable.

The average thickness of the anode is not particularly limited, but is preferably 10 to 500 nm. More preferably, it is 100-200 nm. The average thickness of the anode can be measured by a stylus profilometer or spectroscopic ellipsometry.

In the organic electroluminescent element of the present invention, examples of the cathode include Mg, Ca, Sr, Ba, Li, Al, Au, and alloys containing these. Among these, Mg, Ca, or Al is preferable.

The average thickness of the cathode is not particularly limited, but is preferably 10 to 1000 nm. More preferably, it is 30-150 nm. Even when an opaque material is used, for example, by setting the average thickness to about 10 to 30 nm, it can be used as a top emission type or transparent type cathode.
The average thickness of the cathode can be measured at the time of film formation with a crystal oscillator thickness meter.

In the organic electroluminescent device of the present invention, it is preferable that at least two adjacent layers among the plurality of layers between the cathode and the anode are formed by coating, and the electron injection layer is directly formed on the light emitting layer. It is more preferable that the light emitting layer and the electron injecting layer are formed by coating.
The film formation method by coating includes spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic method. Examples thereof include a printing method, an offset printing method, and an inkjet printing method. Among these, the spin coat method or the slit coat method is preferable because the film thickness can be more easily controlled.

When the organic compound layer is formed by applying an organic compound solution, as a solvent for coating and forming an organic compound layer other than the layer formed by applying the composition for organic electroluminescent elements of the present invention, for example, , Inorganic solvents such as carbon disulfide, carbon tetrachloride, ethylene carbonate, ketone solvents such as methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), cyclohexanone, diethyl ether , Diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol), etc. Tel solvent, cellosolve solvent such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvent such as hexane, pentane, heptane, cyclohexane, aromatic hydrocarbon solvent such as toluene, xylene, benzene, pyridine, Aromatic heterocyclic compounds such as pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, amide solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), chlorobenzene, dichloromethane, chloroform Halogen compound solvents such as 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate, ethyl formate, sulfur compound solvents such as dimethyl sulfoxide (DMSO), sulfolane, acetonitrile, propionitrile, acrylonite Nitrile solvents such as Le, trichloroacetic acid, various organic solvents such as an organic acid solvents such as trifluoroacetic acid or a mixed solvent containing these.
Among these, as the solvent, a nonpolar solvent is suitable, for example, an aromatic hydrocarbon solvent such as xylene, toluene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, pyridine, pyrazine, furan, Examples include aromatic heterocyclic compound solvents such as pyrrole, thiophene, and methylpyrrolidone, and aliphatic hydrocarbon solvents such as hexane, pentane, heptane, and cyclohexane. These can be used alone or in combination.

The organic electroluminescent element of the present invention is preferably sealed. As the sealing step, a normal method can be used as appropriate. For example, a method of adhering a sealing container in an inert gas, a method of forming a sealing film directly on an organic electroluminescent element, or the like can be given. In addition to these, a method of enclosing a moisture absorbing material may be used in combination.

The organic electroluminescent element of the present invention may be one in which each layer constituting the organic electroluminescent element is laminated on a substrate. When each layer is laminated on the substrate, it is preferable that each layer is formed on the electrode formed on the substrate. In this case, the organic electroluminescent element of the present invention may be a top emission type that extracts light to the side opposite to the side where the substrate is present, or a bottom emission type that extracts light to the side where the substrate is present. May be.

As the material of the substrate, resin materials such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, polyarylate, quartz glass, soda glass, etc. A glass material etc. are mentioned, These 1 type (s) or 2 or more types can be used.
In the case of the top emission type, an opaque substrate can be used. For example, an oxide film (insulating film) is formed on the surface of a ceramic substrate such as alumina or a metal substrate such as stainless steel. A substrate made of a resin material or the like can also be used.

The average thickness of the substrate is preferably 0.1 to 30 mm. More preferably, it is 0.1-10 mm.
The average thickness of the substrate can be measured with a digital multimeter or a caliper.

The organic electroluminescent element of the present invention can change the emission color by appropriately selecting the material of the organic compound layer, and can also obtain a desired emission color by using a color filter or the like in combination. Therefore, it can be suitably used as a light emitting part of a display device or a lighting device.

Since the organic electroluminescent element of the present invention has the above-described configuration, it can be applied without dissolving the lower layer when forming the organic compound layer, and the drive voltage of the organic electroluminescent element can be increased. It is possible to suppress. Such a composition for organic electroluminescent elements of the present invention can be suitably used as a light emitting site of a lighting device or a display device.

FIG. 1 is a graph showing the voltage-luminance characteristics of the organic electroluminescent elements produced in Example 1, Comparative Example 1 and Reference Example 1. FIG. 2 is a graph showing the voltage-luminance characteristics of the organic electroluminescent elements prepared in Example 2, Comparative Example 2, and Reference Example 2.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

<Production of organic electroluminescence device>
Example 1
[1] A commercially available transparent glass substrate with an ITO electrode layer having an average thickness of 0.7 mm was prepared. At this time, the ITO electrode (anode) of the substrate used was patterned to a width of 2 mm. This substrate was subjected to ultrasonic cleaning in acetone and isopropanol for 10 minutes, and then boiled in isopropanol for 5 minutes. The substrate was taken out from isopropanol, dried by nitrogen blowing, and UV ozone cleaning was performed for 20 minutes.
[2] This substrate is set on a spin coater, and a commercially available aqueous dispersion of poly (3,4-ethylenedioxythiophene / styrene sulfonic acid) (PEDOT / PSS) is added dropwise to the substrate at 60 rpm at 1,800 rpm. Rotating for 2 seconds and further drying on a hot plate at 150 ° C. for 10 minutes, a hole injection layer made of PEDOT / PSS was formed on the anode. The average thickness of the hole injection layer was 60 nm. The average thickness of the hole injection layer was measured with a stylus type step gauge.
[3] A 0.2% xylene solution of commercially available poly (dioctylfluorene-alt-N- (4-butylphenyl) diphenylamine) (TFB) was prepared. The substrate produced in the above step [2] was set on a spin coater. A TFB-xylene solution is dropped on the hole injection layer formed in the above step [2], rotated at 1000 rpm for 30 seconds, and dried on a hot plate at 200 ° C. for 60 minutes in an argon atmosphere. The excess TFB was removed by rinsing with excess xylene, and an interlayer layer made of TFB was formed on the hole injection layer. The average thickness of the interlayer was 1 nm. The average thickness of the interlayer layer was measured with a stylus type step gauge.
[4] A 1% xylene solution of commercially available poly (dioctylfluorene-alt-benzothiadiazole) (F8BT) was prepared. The substrate produced in the above step [3] was set on a spin coater. An F8BT-xylene solution was dropped on the interlayer layer formed in the above step [3] and rotated at 2,000 rpm for 30 seconds to form a light emitting layer made of F8BT on the interlayer layer. The average thickness of the light emitting layer was 40 nm. The average thickness of the light emitting layer was measured with a stylus type step gauge.
[5] A commercially available mixed ethanol solution of polyethyleneimine SP-200 manufactured by Nippon Shokubai Co., Ltd. and triphenylphosphine oxide was prepared. At this time, the concentration of triphenylphosphine oxide was 0.5%, and the concentration of polyethyleneimine oxide was 1%. The substrate produced in the above step [4] was set on a spin coater. A polyethyleneimine-triphenylphosphine oxide mixed ethanol solution was dropped on the light emitting layer formed in the above step [4] and rotated at 2,000 rpm for 30 seconds to form an electron injection layer on the light emitting layer. . The average thickness of the electron injection layer was 10 nm. The average thickness of the electron injection layer was measured with a stylus type step gauge.
[6] The substrate produced in the above step [5] was fixed to the substrate holder of the vacuum evaporation apparatus. An aluminum wire (Al) was placed in an alumina crucible and set in a vapor deposition source. The inside of the vacuum deposition apparatus was depressurized to about 1 × 10 ⁻⁴ Pa, and Al (cathode) was deposited on the electron injection layer so as to have an average thickness of 100 nm, thereby producing an organic electroluminescence device (1). The average thickness of the cathode was measured at the time of film formation with a crystal oscillator thickness meter. In addition, when vapor-depositing a cathode, the vapor deposition surface was made into the strip | belt shape of width 2mm using the stainless steel vapor deposition mask. That is, the light emitting area of the produced organic electroluminescent element was 4 mm ² .

Example 2
In the step [5], polyethylene glycol (1%)-triphenylphosphine oxide (0.5%) mixed ethanol was used instead of the polyethyleneimine (1%)-triphenylphosphine oxide (0.5%) mixed ethanol solution. An organic electroluminescent element (2) was produced in the same manner as in Example 1 except that it was used. The average thickness of the electron injection layer was 10 nm. The average thickness of the electron injection layer was measured with a stylus type step gauge.

Comparative Example 1
In Step [5], the same procedure as in Example 1 was used except that a polyethyleneimine (1%) ethanol solution was used instead of the polyethyleneimine (1%)-triphenylphosphine oxide (0.5%) mixed ethanol solution. An organic electroluminescent element (Comparative 1) was produced. The average thickness of the electron injection layer was 10 nm. The average thickness of the electron injection layer was measured with a stylus type step gauge.

Comparative Example 2
In Step [5], the same procedure as in Example 2 was performed except that a polyethylene glycol (1%) ethanol solution was used instead of the polyethylene glycol (1%)-triphenylphosphine oxide (0.5%) mixed ethanol solution. An organic electroluminescent element (Comparative 2) was produced. The average thickness of the electron injection layer was 10 nm. The average thickness of the electron injection layer was measured with a stylus type step gauge.

Reference example 1
In Step [5], an organic electroluminescent device (Reference 1) was prepared in the same manner as in Comparative Example 1 except that a polyethyleneimine (0.1%) ethanol solution was used instead of the polyethyleneimine (1%) ethanol solution. Produced. The average thickness of the electron injection layer was 1 nm. The average thickness of the electron injection layer was measured with a stylus type step gauge.

Reference example 2
In Step [5], an organic electroluminescent device (Reference 2) was prepared in the same manner as in Comparative Example 2 except that a polyethylene glycol (0.1%) ethanol solution was used instead of the polyethylene glycol (1%) ethanol solution. Produced. The average thickness of the electron injection layer was 1 nm. The average thickness of the electron injection layer was measured with a stylus type step gauge.

<Measurement of emission characteristics of organic electroluminescence device>
Voltage application to the device and current measurement were performed using a “2400 type source meter” manufactured by Keithley. Luminance was measured with “LS-100” manufactured by Konica Minolta.
The voltage-luminance characteristics of the organic electroluminescent devices (1), (Comparative 1) and (Reference 1) prepared in Example 1, Comparative Example 1 and Reference Example 1 when a DC voltage is applied in an argon atmosphere are shown. As shown in FIG.
The organic electroluminescent elements (2), (Comparative 2) and (Reference 2) produced in Example 2, Comparative Example 2 and Reference Example 2 were subjected to voltage-luminance characteristics when a DC voltage was applied in an argon atmosphere. As shown in FIG.

As is clear from FIG. 1, in Example 1 in which a composition containing polyethyleneimine and triphenylphosphine oxide was used for the electron injection layer, a comparative example in which a composition not containing triphenylphosphine oxide was used for the electron injection layer. Compared to 1, it was found that the increase in drive voltage can be suppressed. Further, in Example 1, an increase in drive voltage can be suppressed to the same extent as in Reference Example 1 in which a composition containing no triphenylphosphine oxide is used for the electron injection layer and the thickness of the electron injection layer is reduced. I understood.
Further, as apparent from FIG. 2, in Example 2 in which a composition containing polyethylene glycol and triphenylphosphine oxide was used for the electron injection layer, a composition not containing triphenylphosphine oxide was used for the electron injection layer. As compared with Comparative Example 2, it was found that the increase in driving voltage can be suppressed. Furthermore, in Example 2, an increase in driving voltage can be suppressed as compared with Reference Example 2 in which a composition containing no triphenylphosphine oxide is used for the electron injection layer and the thickness of the electron injection layer is reduced. I understood.
From the above results, electron injection of the composition of the present invention comprising a polymer having a polyalkylene oxide structure and / or a polyalkyleneimine structure in the main chain skeleton and a π-electron conjugated compound soluble in water or a lower alcohol. In the organic electroluminescent element used for the layer, it was found that an increase in driving voltage can be suppressed even when the electron injection layer is thick.

Claims (4)

For the formation of a layer on a layer formed of a compound that does not dissolve in water or a lower alcohol solvent of an organic electroluminescence device having a structure in which a plurality of layers are laminated between a cathode and an anode formed on a substrate A composition used, comprising:
The compositions viewed contains a polyalkylene oxide structure and / or polyalkylene imine structure and a polymer having a main chain skeleton, a soluble π-electron conjugated compound in water or a lower alcohol,
The π-electron conjugated compound has the following general formula (1), (2) or (3);

(Wherein R ¹ is the same or different and represents an aryl group, aryloxy group, heteroaryl group, or heteroaryloxy group which may have a substituent. R ² is the same or different. And represents a hydrogen atom or a monovalent organic group, n represents the number of benzene rings bonded to the phosphorus atom, and is an integer of 1 to 3.)

(In the formula, R ³ is the same or different and represents a hydrogen atom or a monovalent organic group. When there are a plurality of monovalent organic groups represented by R ³ , some of the plurality of organic groups. Alternatively, all may be bonded to form an aromatic ring or an aromatic heterocyclic ring together with a part of the aromatic heterocyclic ring containing N. A part of the plurality of organic groups may be bonded to form an aromatic ring or aromatic ring. In the case where a heterocyclic group is formed, the remaining organic group may be bonded to an aromatic ring or an aromatic heterocyclic ring formed from a part of the plurality of organic groups, or an aromatic group containing N. It may be bonded to a heterocyclic group. M represents the number of R ³ bonded to the aromatic heterocyclic ring containing N, and is an integer of 1 to ^3. )

(In the formula, R ⁴ and R ⁵ are the same or different and represent a hydrogen atom or a monovalent organic group. X ¹ and X ² are the same or different and represent a carbon atom, a nitrogen atom or an oxygen atom. The bond portion that connects the carbon atom to which X ¹ and R ⁴ are bonded, and the dotted line portion in the bond portion that connects the carbon atom to which X ² and R ⁴ are bonded are double X ¹ or X ² and the carbon atom. (Indicates that it may be connected by a bond.)
The composition for organic electroluminescent elements characterized by being one of the compounds represented by these. The composition for an organic electroluminescent element is used for an organic electroluminescent element in which at least one layer among a plurality of layers between a cathode and an anode is formed by coating. Composition for organic electroluminescence device. The polymer has a main chain skeleton having a polyalkylene oxide structure formed by an alkylene oxide having 2 to 4 carbon atoms and / or a polyalkylene imine structure formed by an alkylene imine having 2 to 4 carbon atoms. The composition for organic electroluminescent elements according to claim 1 or 2 . It forms using the composition for organic electroluminescent elements in any one of Claims 1-3 , The organic electroluminescent element characterized by the above-mentioned.

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