TW201427136A - Organic electroluminescent element - Google Patents

Abstract

The object of the present invention is to provide an organic electroluminescent element using a light-scattering hole injecting and transporting layer, which is capable of easily forming by a coating or likes and is excellent in an efficiency of light ejection. The organic electroluminescent element of the present invention is an organic electroluminescent element comprises: an anode, a cathode, and at least one layer selected from a hole injecting layer and a hole transporting layer, which are formed between the anode and the cathode, wherein at least one layer selected from the hole injecting layer and the hole transporting layer includes dispersed particles, and at least one layer selected from the hole injecting layer and the hole transporting layer has a thickness of 100 nm or more and 1000 nm or less.

Description

Organic electric field light-emitting element and method of manufacturing same

The present invention relates to an organic electric field light-emitting element and a method of manufacturing the same.

An organic electroluminescent device (hereinafter referred to as "electroluminescence" includes an anode, a cathode, and a light-emitting layer formed between two electrodes on a glass substrate. The light-emitting layer is generated by energization of the two electrodes. The light is taken out to the outside through the anode (for example, a transparent electrode such as ITO) and the glass substrate. However, it is known that at the interface between the light-emitting layer and the ITO, the interface between the ITO and the glass substrate, and the interface between the glass substrate and the atmosphere, The reflection due to the difference in refractive index is generated, so that most of the luminescent light cannot be taken out, and the light taken out is only about 20% of the luminescent light.

A method of introducing a light scattering layer for improving the light extraction efficiency of an organic electric field light-emitting element is known. The light scattering layer has different effects depending on the position to be introduced, and when it is disposed between the light-emitting layer and the anode (ITO or the like), the highest light extraction effect can be obtained. The reason is that a scattering effect can be imparted to the luminescent light that is reflected at the light-emitting layer and all the interfaces of the ITO, the ITO and the glass substrate, and the glass substrate and the atmosphere.

It has been reported that when a light-scattering layer is formed between the light-emitting layer and the anode (ITO or the like), it is also carried out by a simple and highly productive coating method.

For example, Patent Document 1 discloses a general organic resin such as polymethyl methacrylate The material is coated with a material in which inorganic conductive fine particles such as ITO are dispersed to form a light-scattering layer.

Further, the organic electroluminescent device disclosed in Patent Document 2 is a poly(3,4-ethylenedioxythiophene)/polystyrenesulfonic acid (hereinafter referred to as "PEDOT/" which is a hole injecting and transporting material. In PSS"), a hole transport layer in which cerium oxide particles or silver nanoparticles are dispersed is dispersed.

Further, Patent Document 3 reports that the luminous efficiency of an organic electric field element is improved by using a PEDOT/PSS layer in which cerium oxide particles having a particle diameter of 1 to 100 nm and titanium oxide particles having a particle diameter of 100 to 1000 nm are co-dispersed.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent No. 4949149

Patent Document 2: International Publication No. 2009/141903

Patent Document 3: US Patent Application Publication No. 2011/0045392

However, in the light-scattering layer described in Patent Document 1, since the general-purpose organic resin (generally having a refractive index of less than 1.5 to 1.6) is used as the bonding component, it is predicted that the light-scattering layer and the light-emitting layer are formed (generally, the refractive index is 1.7 or more). The effect of total reflection at the interface and the removal of light is low. In fact, the publication has a film thickness of 4 μm or more. Further, since the general-purpose organic resin is inferior in solvent resistance and heat resistance and has a large thermal expansion coefficient, it is limited in the production of an organic electroluminescent device. Further, since it is additionally formed for the purpose of obtaining only the light scattering function, there is a problem that it is necessary to add a step in the production of the organic electric field light-emitting element.

On the other hand, Patent Document 2 is based on a material that will be transported in a hole. The dispersion in which the particles are mixed in the PEDOT/PSS is subjected to spin coating to form a hole injecting layer containing particles. Although it is a simple method in which the hole transport layer and the scattering layer can be formed in one coating step, the light extraction effect cannot be obtained as shown in Comparative Examples 1 and 2 described later. When the particle diameter is about 20 to 30 nm and the thickness of the hole transport layer is less than 100 nm, the light scattering property is weak, and it is estimated that the light extraction effect cannot be exhibited.

Patent Document 3 discloses that an organic electric field element of a PEDOT/PSS layer in which a cerium oxide particle having a particle diameter of 20 to 30 nm and a titanium oxide particle having a particle diameter of 20 to 130 nm is co-dispersed is used to improve the luminous efficiency. However, in PEDOT/PSS, in addition to the above particles, DMSO which is a high boiling point solvent is added to improve conductivity, and the addition of DMSO may lower the driving voltage to increase the luminous efficiency. Therefore, Patent Document 3 considers that the improvement in light extraction efficiency caused by the above-described particles is not clearly described. Also, since PEDOT/PSS is generally supplied only by a thin dispersion, it is actually difficult to obtain a sufficient film thickness. When PEDOT/PSS which is a binder is used and a sufficient film thickness cannot be obtained, the above-mentioned particles may become protrusions on the surface of the coating film. This phenomenon can cause a short circuit or no light emission of the organic electric field light-emitting element. The embodiment of Patent Document 3 does not describe the film thickness of the hole transport layer at all.

As described above, although there has been a report of attempting to form a light-scattering film by applying a hole transporting material containing particles, a practical technique has not yet been reached. The reason is that a hole injection transport layer having effective light scattering energy can be obtained, and various conditions such as a structure of a hole transporting material, a particle condition, a film thickness, and a surface shape are required.

An object of the present invention is to provide an organic electroluminescence device which is formed by using a light-scattering hole which is easily formed by coating or the like and which is excellent in light extraction efficiency.

The inventors of the present invention have made intensive studies in view of the above problems, and have found that the film thickness of at least one layer selected from the hole injection layer and the hole transport layer is set to 100 nm or more and 1000 nm or less. The above problem can be solved by selecting at least one of the hole injection layer and the hole transport layer to be dispersed, and the present invention has been completed.

That is, the present invention is as follows.

[1] An organic electroluminescence device comprising: an anode and a cathode; and an organic electroluminescent element selected from at least one of a hole injection layer and a hole transport layer formed between the anode and the cathode The film is dispersed in at least one of the hole injection layer and the hole transport layer, and at least one layer is selected from the hole injection layer and the hole transport layer. 100 nm or more and 1000 nm or less.

[2] The organic electroluminescence device according to the above [1], wherein the hole injecting the transport material is selected from at least one of the hole injection layer and the hole transport layer. Amine polymer compound.

[3] The organic electroluminescent device according to the above [1], wherein the particles are at least one selected from the group consisting of metal oxides, composite oxides, and polymer materials.

The organic electroluminescent device of any one of the above-mentioned [1], wherein the average particle diameter of the particles is 10 nm or more and 300 nm or less.

[5] The organic electroluminescence device according to any one of the above [1], wherein at least one of the hole injection layer and the hole transport layer is selected from the group consisting of the hole injection layer and the hole transport layer. Membrane formation.

[6] The organic electroluminescence device according to any one of [1] to [5] further comprising a hole transport layer and a light-emitting layer.

[7] An organic EL display device comprising the method according to any one of the above [1] to [6] Machine electric field illuminating element.

[8] An organic EL illumination device according to any one of the above [1] to [6].

According to the present invention, it is possible to provide an organic electroluminescence device in which at least one layer is selected from a light-scattering hole injection layer and a hole transport layer which are easily and easily used by coating or the like and which have excellent light extraction efficiency.

1‧‧‧ hole injection layer

2‧‧‧ hole transport layer

3‧‧‧Lighting layer

4‧‧‧Electronic injection layer

5‧‧‧ cathode

6‧‧‧Anode

7‧‧‧ glass substrate

8‧‧‧

9‧‧‧Flake dehydrated material

10‧‧‧ cone glass

11‧‧‧Photocurable resin

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an example of an embodiment of an organic electroluminescence device of the present invention.

Fig. 2 is a schematic cross-sectional view showing another example of the embodiment of the organic electroluminescent device of the present invention.

The present invention will be described in detail below, but the present invention is not limited by the following description without departing from the scope of the invention. Further, the present invention will be described with reference to the appropriate drawings.

The present invention exists as follows.

An organic electroluminescence device comprising: an anode and a cathode; and an organic electroluminescence element formed between the anode and the cathode to form at least one layer from the hole injection layer and the hole transport layer; wherein The particles are dispersed in at least one of the hole injection layer and the hole transport layer, and at least one of the hole injection layer and the hole transport layer is selected to have a thickness of 100 nm or more. Below 1000nm."

The organic electroluminescence device of the present invention includes an anode and a cathode, and includes at least one layer selected from a hole injection layer and a hole transport layer formed between the anode and the cathode. In addition, the correlation selects at least one layer from the hole injection layer and the hole transport layer. In addition, an organic semiconductor layer which is formed between the anode and the cathode can be described later. In addition, the hole injection layer and the hole transport layer are also collectively referred to as "hole injection and transport layer".

1. Hole injection ‧ transport layer

As shown in Fig. 1 and Fig. 2, the hole injection/transport layer (1, 2) of the present invention is responsible for injecting and transporting a layer of a hole from the anode 6 side toward the light-emitting layer 3 side, and is formed adjacent to the anode 6. Further, it is preferable that the hole injection/transport layer (1, 2) strengthens the function of injecting a hole from the anode 6 toward the light-emitting layer 3 side.

The thickness of the hole injection/transport layer (1, 2) is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more. Further, it is usually 1000 nm or less, preferably 900 nm or less, more preferably 800 nm or less. If it is within the above range, it is a thickness that can obtain a sufficient scattering effect, and the loss of light amount due to the absorption of the hole injection layer itself does not exceed the thickness of the light amount gain due to the scattering effect, and thus is suitable. It is a light scattering film.

Further, the two layers of the hole injection layer 1 and the hole transport layer 2 may be formed according to the film thickness, or any one of them may be formed according to the film thickness. It is preferable that the layer in which the particles are dispersed as described later is formed in accordance with the above film thickness.

The hole injection ‧ transport layer (1, 2) preferably contains a hole injection transport compound, and more preferably contains a hole injection transport compound and an electron acceptor compound. Further, it is preferable that the hole injection layer contains a cationic radical compound, more preferably a cationic radical compound, and a hole injection transporting compound.

The hole injection layer of the present invention is formed by a wet film formation method. The method of forming the hole injection layer will be described below.

<hole injection of transportable compound>

In the case of performing wet film formation, the hole is injected into the hole and injected into the front layer of the transport layer, and the composition for forming the transport layer is usually filled with a hole which is to be injected into the hole and transport layer. Transportable compound. Further, when the wet film formation method is carried out, it usually contains a solvent. The hole injection ‧ the composition for forming the transport layer is preferably a hole in which the hole is injected and the transport hole is injected with high energy efficiency. Therefore, it is preferable that the hole mobility is large, and it is less likely to cause impurities which may become traps at the time of manufacture and use. Further, it is preferably excellent in stability, small in ionization potential, and high in transparency to visible light. In particular, when the hole injection layer is adjacent to the light-emitting layer, it is preferred that the light-emitting layer from the light-emitting layer does not emit light or does not form an excimer with the light-emitting layer, resulting in a decrease in luminous efficiency.

The hole injection polymerizable compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV from the viewpoint of the charge injection barrier of the ‧ transport layer from the anode to the hole. Examples of the hole injection-transporting compound include, for example, an aromatic amine compound, a phthalocyanine compound, a porphyrin compound, an oligothiophene compound, a polythiophene compound, a benzylphenyl compound, and a tertiary group bonded by a thiol group. An amine compound, an anthraquinone compound, a decazane compound, a quinophthalone compound, or the like.

Among the above-exemplified compounds, an aromatic amine compound and a more preferred aromatic tertiary amine polymer compound are preferred from the viewpoint of amorphousness and visible light transmittance. Here, the "aromatic tertiary amine polymer compound" means a compound having an aromatic tertiary amine structure, and also includes a compound having a group derived from an aromatic tertiary amine.

The type of the aromatic tertiary amine polymer compound is not particularly limited, and a polymer compound having a weight average molecular weight of 3,000 or more and 1,000,000 or less is preferably used from the viewpoint of more easily obtaining a uniform light emission by the surface smoothing effect. A polymeric compound in which repeating units are linked together).

Since the aromatic tertiary amine polymer compound can be uniformly dissolved in the solvent, the aromatic tertiary amine polymer compound solution can be regarded as a uniform dispersion medium. Therefore, the particles can be uniformly dispersed, and the film obtained by the film formation can obtain a film in which the particles are uniformly dispersed.

On the other hand, the PEDOT/PSS solutions described in Patent Documents 2 and 3 are bonded to PSS by PEDOT to form clusters. That is, the cluster belonging to the dispersoid is a dispersion liquid dispersed in an aqueous solvent belonging to a dispersion medium. Since the solid content concentration of the PEDOT/PSS dispersion is usually several % or less, when any particles are dispersed in the dispersion, the dispersion is usually dispersed, and it is difficult to disperse the particles in the dispersion. As a result, if the film formation is carried out, the state in which the particles are agglomerated appears, which makes it difficult to obtain a film in which the particles are uniformly dispersed.

Further, since the PSS system contains a sulfonic acid group, the PEDOT/PSS dispersion is acidic, and if the dispersion of the particles is more mixed therein, the dispersibility of the particles is deteriorated due to the acidic relationship, and aggregation is likely to occur. Precipitation situation. Therefore, it is difficult to use such a dispersion to obtain a film in which particles are uniformly dispersed in PEDOT/PSS.

Hereinafter, the aromatic tertiary amine polymer compound will be described in detail.

(related molecular weight)

The aromatic tertiary amine polymer compound of the present invention has a weight average molecular weight (Mw) of 3,000 or more and 1,000,000 or less, and is quite suitable for an organic electroluminescent device.

When the weight average molecular weight of the aromatic tertiary amine polymer compound is within the above range, the solubility of the aromatic tertiary amine polymer compound in an organic solvent is good at the time of wet film formation, and it is easier to form a uniform film because It is difficult to cause high molecular weight of impurities, so refining is easy, and industrial disadvantages are less likely to occur.

Further, when the weight average molecular weight is lower than the lower limit value, the glass transition temperature, the melting point, and the vaporization temperature are lowered, so that heat resistance may be significantly impaired.

When the layer containing the aromatic tertiary amine polymer compound is formed by a wet film formation method, the weight average molecular weight is preferably 100,000 or less, more preferably 60,000 from the viewpoints of solubility, film formability, and heat resistance. the following. Similarly, the lower limit is preferably 5,000 or more, more preferably 10,000 or more.

Further, the number average molecular weight (Mn) of the aromatic tertiary amine polymer compound of the present invention is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and usually 500 or more, preferably 1,500 or more. More preferably, it is more than 3,000.

Further, the degree of dispersion (Mw/Mn) of the aromatic tertiary amine polymer compound of the present invention is usually 10 or less, preferably 2.5 or less, more preferably 2.0 or less, and more preferably 1.0 or more, and more preferably 1.1. The above is particularly good for 1.2 or more.

If it is in the above range, it can be easily purified, and the aromatic tertiary amine polymer compound is excellent in solubility in an organic solvent and charge transporting ability, and is preferable.

The weight average molecular weight (and number average molecular weight) of the present invention is determined by SEC (size exclusion chromatography) measurement. In the SEC measurement, the higher the molecular weight component, the shorter the elution time, and the lower the molecular weight component, the longer the elution time is, and the calibration curve calculated from the dissolution time of the known molecular weight polystyrene (standard sample) is used. The weight average molecular weight (and the number average molecular weight) can be calculated by converting the dissolution time of the sample into a molecular weight.

(related preferred repeating unit)

The aromatic tertiary amine polymer compound contained in the composition for an organic electroluminescence device of the present invention preferably contains a polymer having a repeating unit represented by the following formula (2).

[Chemical 1]

(In the formula (2), m represents an integer of 0 to 3; and Ar ³¹ and Ar ³² represent a divalent or aromatic hydrocarbon ring group which may be independently bonded, or may have a substituent. An aromatic heterocyclic group; Ar ³³ to Ar ³⁵ are each an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ³³ and Ar ³⁵ represent a monovalent group. Ar ³⁴ represents a divalent group. However, both Ar ³¹ and Ar ^{32 are} not directly bonded at the same time.

Further, in the case of the formula (2), when Ar ³⁴ and Ar ³⁵ are plural, the lines may be the same or different. )

In the formula (2), Ar ³¹ and Ar ³² each represent a divalent or aromatic aromatic hydrocarbon group which may be independently bonded, or an aromatic heterocyclic group which may have a substituent; Ar ³³ ~ Ar ³⁵ represents an aromatic hydrocarbon ring group which may be independently substituted or an aromatic heterocyclic group which may have a substituent.

The aromatic hydrocarbon ring group which may have a substituent may, for example, have one or two free valence benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, anthracene rings, tetraazene rings, anthracene rings, benzofluorenes. ring, A monocyclic or 2~5 condensed ring of a six-membered ring having one or two free valences, such as a ring, a triphenyl ring, an anthracene ring, a scallion ring, or an anthracene ring. Here, the "free valence" in the present invention is as described in the Organic Chemistry ‧ Biochemical Nomenclature (I) (Revised 2nd Edition, Nan Jiang Tang, published in 1992), which means that a bond can be formed with other free valences. .

The aromatic heterocyclic group which may have a substituent may, for example, have one or two free valences of a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, Diazole ring, anthracene ring, indazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, fluorinated pyrrole ring, fluorinated furan ring, thiophene Furan ring, benzopyrene Oxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyridyl Ring, 哒 Ring, pyrimidine ring, three Ring, quinoline ring, isoquinoline ring, Porphyrin ring, quinolin a ring of five or six-membered rings having one or two free valences, such as a porphyrin ring, a phenanthridine ring, a benzimidazole ring, an acridine ring, a quinazoline ring, a quinazolinone ring, an anthracene ring, or the like ~4 condensed ring.

From the viewpoints of solubility to a solvent and heat resistance, Ar ³¹ to Ar ^{35 are} preferably a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene having one or two free valences, which may be independently or independently substituted. A ring selected from the group consisting of a ring, a triphenyl ring, an anthracene ring, a thiophene ring, a pyridine ring, and an anthracene ring.

Further, Ar ³¹ to Ar ^{35 are} preferably a group in which one or two or more kinds of rings are directly bonded from the above group or a group which is bonded by a -CH=CH- group, and more preferably a biphenyl group. And triphenyl and the like.

The aromatic hydrocarbon ring group which may have a substituent and the aromatic heterocyclic group which may have a substituent may be, for example, the group described in the following <Substituent Group Z>.

<Substituent group Z>

A methyl group, an ethyl group or the like preferably has an alkyl group having 1 to 24 carbon atoms and more preferably 1 to 12 carbon atoms; a vinyl group or the like preferably having 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms; an ethynyl group or the like. Preferably, the alkynyl group having a carbon number of 2 to 24, more preferably having a carbon number of 2 to 12; a methoxy group having a preferred carbon number of 1 to 24, more preferably having a carbon number of 1 to 12; a methoxy group; More preferably, the naphthyloxy group, the pyridyloxy group and the like have an aryloxy group having 4 to 36 carbon atoms and more preferably 5 to 24 carbon atoms; the methoxycarbonyl group and the ethoxycarbonyl group have a preferred carbon number of 2 to 24, more preferably 2 carbon atoms; ~12 alkoxycarbonyl; Preferred dimethylamino group, diethylamino group, etc., preferably having 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms; diphenylamine group, xylylene group, N-carbazolyl group, etc. 10 to 36, more preferably 12 to 24 diarylamine groups; phenylmethylamino group and the like preferably 6 to 36 carbon atoms, more preferably 7 to 24 carbon atoms arylalkylamine groups; ethyl sulfonyl group, benzene Mercapto group and the like preferably having a carbon number of 2 to 24, more preferably a carbon number of 2 to 12; a halogen atom such as a fluorine atom or a chlorine atom; a trifluoromethyl group having a preferred carbon number of 1 to 12, more preferably a carbon number of 1 ~6 haloalkyl; methylthio, ethylthio and the like preferably having a carbon number of 1 to 24, more preferably having a carbon number of 1 to 12; a preferred carbon such as a phenylthio group, a naphthylthio group or a pyridylthio group; a number of 4 to 36, more preferably a carbon number of 5 to 24 arylthio groups; a trimethyl decyl group, a triphenyl decyl group, etc., preferably having a carbon number of 2 to 36, more preferably a carbon number of 3 to 24; Preferably, the oxyalkylene group, the triphenylphosphonium oxyalkyl group and the like have a carbon number of 2 to 36, more preferably a carbon number of 3 to 24; a cyano group; a phenyl group, a naphthyl group or the like, preferably a carbon number of 6~ 36. More preferably, the aromatic hydrocarbon ring group having 6 to 24 carbon atoms; the thienyl group and the pyridyl group are preferably an aromatic heterocyclic group having 3 to 36 carbon atoms and more preferably 4 to 24 carbon atoms.

Each of the above substituents may further have a substituent, and examples thereof may be, for example, the groups exemplified for the above substituent group Z.

The aromatic hydrocarbon ring group and the aromatic heterocyclic group in Ar ³¹ to Ar ³⁵ may have a molecular weight of a substituent, and are preferably 500 or less, more preferably 250 or less, including a further substituted group.

From the viewpoint of solubility in a solvent, the substituent which the aromatic hydrocarbon ring group and the aromatic heterocyclic group in Ar ³¹ to Ar ³⁵ may have are preferably each independently an alkyl group having 1 to 12 carbon atoms and carbon. Alkoxy groups numbered from 1 to 12.

Further, when m is 2 or more, the repeating unit represented by the above formula (2) has two or more Ar ³⁴ and Ar ³⁵ . In this case, the Ar ³⁴ and the Ar ³⁵ may be the same or different from each other. Further, the Ar ³⁴ and the Ar ³⁵ may be directly bonded to each other or to each other via a linking group to form a cyclic structure.

m of the formula (2) represents an integer of 0 or more and 3 or less.

From the viewpoint of improving the solubility and film formability of the aromatic tertiary amine polymer compound in an organic solvent, m is preferably 0.

In addition, from the viewpoint of enhancing the hole transporting ability of the aromatic tertiary amine polymer compound, m is 1 or more and 3 or less.

(conjugated polymer)

Since the aromatic tertiary amine polymer compound of the present invention is a repeating unit having a conjugated structure, it is preferably a conjugated polymer from the viewpoint of having sufficient charge transporting ability and sufficient solubility to a solvent.

More specifically, a polymer composed of a repeating unit represented by the above formula (2) is preferred.

(insoluble base)

In addition, when the aromatic tertiary amide polymer compound of the present invention is a conjugated polymer, it is preferable to further insolubilize from the viewpoint of being easy to laminate and having excellent surface flatness at the time of film formation. base. That is, the aromatic tertiary amine polymer compound of the present invention is preferably a conjugated polymer having an insolubilizing group.

The term "insolubilizing group" refers to the use of active energy lines such as heat and/or light. The base which reacts by the reaction, and has a group which can reduce the solubility effect on the organic solvent and water compared with the reaction before the reaction.

In the present invention, the insolubilizing group is preferably a dissociable group or a crosslinkable group.

The substituent of the aromatic tertiary amine polymer compound is a group containing an insolubilizing group, and the position having an insolubilizing group may be in the repeating unit represented by the above formula (2), or may be represented by the formula (2). A portion other than the repeating unit (for example, a terminal group).

In the following, an aromatic tertiary amine polymer compound having a dissociable group is also referred to as a "dissociable polymer", and an aromatic tertiary amine polymer compound having a crosslinkable group is also referred to as "highly crosslinkable". The situation of the molecule.

<dissociation base>

The "dissociable group" means a group which is soluble in a solvent, and is thermally dissociated from a bonded group (for example, a hydrocarbon ring) at 70 ° C or higher. Further, by dissociating the dissociable group, the solubility of the polymer in the solvent can be lowered.

However, after dissociation, a group which undergoes a bonding reaction with other atoms (for example, dissociation by hydrolysis) is excluded. The group dissociated by hydrolysis will have active protons in the molecule after dissociation. If the active proton is present in the element, it will affect the characteristics of the element.

The dissociative group is bonded to the hydrocarbon ring, which is preferably condensed on an aromatic hydrocarbon ring having no polar group, preferably using a retro Diels-Alder reaction. ) the base for thermal dissociation.

Further, the temperature at which thermal dissociation is carried out is preferably 100 ° C or higher, more preferably 120 ° C or higher, and is preferably 300 ° C or lower, more preferably 240 ° C or lower.

If it is within the above range, the synthesis of the polymer is easy, and it is difficult to induce at the time of film formation. The compound is decomposed and the like.

Further, in particular, it has a group having a three-dimensional structure for suppressing the intermolecular stacking, and is preferred because it is excellent in solubility. An example of a reaction in which a dissociable group is dissociated from a compound is as follows.

Further, in the case of the above reaction formula, the dissociable group is a portion surrounded by a circular frame in the structure shown below.

Examples of dissociation of such dissociable groups are, for example, desulfinylacetamide (see JACS, V124, No. 30, 2002, 8813); dealkylation, dealcoholation, dealkylation (see H. kwart and K. King, Department of Chemistry, University of Delaware, Nework, Delaware 19771, p415-447 (1967), O. Diels and K. Alder, Ber., 62, 554 (1929) and MC Kloetzel, Org. Reactions, 4, 6 ( 1948)); Azole (cf. ND Field, J. Am. Chem. Soc., 83, 3504 (1961)); de-diene (cf. R. Huisgen, M. Seidel, G. Wallbillich, and H. Knupfer, Tetrahedron, 17, 3 ( 1962)); Azole (cf. R. Huisgen and M, Christi, Angew. Chem. Intern. Ed. Engl., 5, 456 (1967)); detriazole (cf. R. Kreher and J. Seubert, Z. Naturforach., 20B, 75 ( 1965)) and so on.

Among the above, in particular, from the viewpoint that the dissociable group is more stable and easier to synthesize, the hydrocarbon ring to which the dissociable group is bonded is preferably a ring containing an ethylene bridging group or an ethylene bridging group.

Such a dissociable group can prevent the intermolecular stacking of its bulky molecular structure or the polymer having good solubility to an organic coating solvent before heat treatment. Further, since the dissociable group is dissociated from the polymer by the heat treatment, the solubility of the compound after heating to the solvent can be remarkably suppressed, and the organic layer containing the compound can be provided with an organic solvent-repellent property. Therefore, on the organic layer formed by using the dissociable polymer of the present invention, the organic thin film can be easily laminated by a wet film formation method.

Specific examples of the group containing the dissociable group are as follows, but the present invention is not limited to the above.

A specific example of the case where the group containing a dissociable group is a divalent group is the following <base group A containing a divalent dissociable group>.

<base group A containing a divalent dissociable group>

Specific examples of the dissociative group monovalent group are as follows: <base group B containing a monovalent dissociable group>.

<base group B containing a monovalent dissociable group>

<Arrangement and ratio of repeating units, etc.>

The conjugated polymer having a dissociable group has a dissociative group in the structure, and the structure of the repeating unit or the like is not particularly limited, and it is preferred that the repeating unit has an aromatic ring in the aromatic ring. The above dissociable group is bonded to the condensed hydrocarbon ring.

Further, among them, from the viewpoint of excellent film formability, a conjugated polymer having a dissociative group containing a repeating unit is preferable, and the repeating unit has a dissociable group bond containing an ethylene bridging group or an ethylene bridging group. Part of the structure of the knot.

Further, the ethylene bridging group or the ethylene bridging group is preferably contained in a hydrocarbon ring, and the hydrocarbon ring is more preferably a six-membered ring.

The conjugated polymer having a dissociable group of the present invention has a repeating unit having a structure of a bonded portion of a dissociable group, and preferably contains a repeating unit having a partial structure represented by the following chemical formula (U3) or (U4). In this case, the content of the repeating unit (U3) or (U4) in the polymer chain is preferably 10 mol% or more, more preferably 30 mol% or more.

(In the formula (U3), the ring A ¹ represents an aromatic ring. The aromatic ring may have a substituent. Further, the substituent may form a ring directly or via a divalent linking group. S ²¹ , S ²² R ²¹ to R ²⁶ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, and An aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an indenyl group which may have a substituent, an alkenyl group which may have a substituent, or may have The alkynyl group of the substituent, the oxime group which may have a substituent, the arylamine group which may have a substituent, the heteroarylamine group which may have a substituent, or the mercaptoamine group which may have a substituent. ¹ and X ² are each a divalent aromatic hydrocarbon ring group having 6 or more and 50 or less carbon atoms which may have a substituent, or a divalent aromatic group having 5 or more and 50 or less carbon atoms which may have a substituent. Heterocyclic group.

In the formula (U4), the ring B ¹ represents an aromatic ring. The above aromatic ring may have a substituent. Further, the substituents may form a ring directly or via a divalent linking group. S ³¹ to S ³⁴ , R ³¹ to R ³⁶ , X ³ and X ⁴ are each independently the same as those exemplified for the above S ²¹ , S ²² , R ²¹ to R ²⁶ , X ¹ and X ² . n ¹ to n ⁴ represent integers of 0 to 5 which are independent of each other. )

In the chemical formulas (U3) and (U4), the ring A ¹ and the ring B ¹ each represent an aromatic ring to which a dissociable group is bonded, and may be an aromatic hydrocarbon ring or an aromatic hetero ring, and it is an electrochemistry. From the viewpoint of excellent stability and difficulty in localization of charge, an aromatic hydrocarbon ring is preferred. Further, the aromatic ring may have a substituent. Further, the substituents may form a ring directly or via a divalent linking group.

When the ring A ¹ and the ring B ¹ are aromatic hydrocarbon rings, the number of carbon atoms in the aromatic hydrocarbon ring is usually 6 or more. Further, it is usually 40 or less, preferably 30 or less, and more preferably 20 or less. Further, when the ring A ¹ and the ring B ¹ are aromatic heterocyclic rings, the number of nucleus carbon atoms of the aromatic heterocyclic ring is usually 3 or more, preferably 4 or more, more preferably 5 or more. Further, it is usually 50 or less, preferably 30 or less, and more preferably 20 or less.

The aromatic hydrocarbon ring system may be, for example, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, an anthracene ring, a tetraazene ring, an anthracene ring, a benzofluorene ring, Ring, benzo Ring, extended triphenyl ring, scallions ring, ring and so on.

Among the above, the ring A ¹ and the ring B ¹ are each preferably selected from the group consisting of a benzene ring, a naphthalene ring, an anthracene ring and a tetrazene ring.

Further, the aromatic heterocyclic ring may be, for example, a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, Diazole ring, anthracene ring, indazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, fluorinated pyrrole ring, fluorinated furan ring, thiophene Furan ring, benzopyrene Oxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyridyl Ring, 哒 Ring, pyrimidine ring, quinoline ring, isoquinoline ring, quin A porphin ring, an acridine ring, a quinazoline ring, a quinazolinone ring or the like.

Further, the ring A ¹ and the ring B ¹ in the above chemical formulas (U3) and (U4) may be formed of two or more kinds of ring structure units of the same type or different types of 1 or more and 10 or less, and may be contained directly or via One or more divalent linking groups are selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, a chain group having a nucleus carbon number of 1 or more and 20 or less, and an aliphatic group having 1 or more carbon atoms and 20 or less carbon atoms. Structure. Further, the ring structure unit to be linked may be the same as the above-mentioned aromatic hydrocarbon ring or aromatic hetero ring, or may form a different aromatic hydrocarbon ring or aromatic hetero ring. Further, the aromatic hydrocarbon ring and the aromatic heterocyclic ring may have a substituent.

The substituent of the ring A ¹ or the ring B ¹ may be, for example, a methyl group, an ethyl group, a n-propyl group, a 2-propyl group, a n-butyl group, an isobutyl group or a t-butyl group having a carbon number of 1 or more and 10 or less. a linear or branched alkyl group; an alkenyl group having 1 or more and 8 or less carbon atoms such as a vinyl group, an allyl group or a 1-butenyl group; an alkynyl group having 1 or more and 8 or less carbon atoms such as an ethynyl group or a propynyl group; An aralkyl group having a carbon number of 2 or more and 8 or less; an arylamine group such as an anilino group, a diphenylamino group or a xylylene group; a heteroarylamino group such as a pyridylamino group, a thienylamino group or a dithienylamino group; a mercaptoamine group such as a sulfhydryl group or a benzhydrylamino group; an alkoxy group having 1 or more and 8 or less carbon atoms such as a methoxy group, an ethoxy group or a butoxy group; an acryloxy group and a methylcarbonyloxy group; a fluorenyloxy group having 1 or more and 15 or less carbon atoms such as an ethoxycarbonyloxy group, a hydroxycarbonylmethylcarbonyloxy group, a hydroxycarbonylethylcarbonyloxy group or a hydroxyphenylcarbonyloxy group; a phenoxy group, a 1-naphthyloxy group, and a 2- An aryloxy group having a carbon number of 10 or more and 20 or less, such as a naphthyloxy group. The substituents may also be directly or via -O-, -S-, >CO, >SO ₂ , -(C _α H _2α )-, -O-(C _β H _2β )-, substituted or unsubstituted The alkylene group having 2 or more carbon atoms and 20 or less carbon atoms may be bonded to a divalent linking group such as an alkylene group having 2 or more and 20 or less carbon atoms having a substituent to form a cyclic structure. The above α and β each represent an integer of 1 or more and 20 or less.

These substituents may be substituted with one or two or more, or one or two or more of the ring A ¹ or the ring B ¹ .

In the above chemical formula (U3) and chemical formula (U4), S ²¹ , S ²² , R ²¹ to R ²⁶ , S ³¹ -S ³⁴ , and R ³¹ to R ³⁶ represent independent hydrogen atoms; hydroxyl group; methyl group, ethyl group a n-propyl group, a 2-propyl group, a n-butyl group, an isobutyl group, a tert-butyl group or the like, which may have a substituent or a straight or branched alkyl group having a carbon number of usually 1 or more and usually 50 or less, preferably 10 or less. Or an aromatic hydrocarbon ring group having a nucleus carbon number of 5 or more and 50 or less, or an aromatic heterocyclic group having a nucleus number of 5 or more and 40 or less, or a benzyl group or the like The number of carbon atoms of the substituent is usually 6 or more, preferably 7 or more, and usually 50 or less, preferably 8 or less; methoxy, ethoxy, butoxy or the like may have a carbon number of a substituent. An alkoxy group of 1 or more, usually 50 or less, preferably 8 or less; a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group or the like may have a substituent having a nucleus carbon number of usually 5 or more, preferably 6 or more. And an aryloxy group of usually 50 or less, preferably 15 or less; or a fluorenyl group having a substituent having a nucleus carbon number of usually 2 or more and 50 or less; a vinyl group, an allyl group, a 1-butenyl group, or the like The alkenyl group having a carbon number of the substituent is usually 1 or more and 8 or less; the ethynyl group, the propynyl group or the like may have an alkynyl group having a carbon number of usually 1 or more and 8 or less; an acryloxy group, a methoxycarbonyl group; Further, an ethoxycarbonyl group, a hydroxycarbonylmethylcarbonyloxy group, a hydroxycarbonylethylcarbonyloxy group, a hydroxyphenylcarbonyloxy group or the like may have a substituent having a nucleus carbon number of usually 2 or more, usually 50 or less, preferably 15 or less. An aryl group, an anilino group, a diphenylamino group, a xylylene group, or the like may have an arylamine group having a nucleus carbon number of usually 6 or more and 50 or less; a pyridylamino group, a thienylamino group, a dithienylamino group, or the like may be used. a heteroarylamine group having a substituent having a nucleus carbon number of usually 5 or more and 50 or less; or a fluorenyl group having a carbon number of 2 or more and 50 or less, which may have a substituent, such as an acetylamino group or a benzhydrylamino group. Amine.

The conjugated polymer having a dissociable group of the present invention preferably contains a repeating unit represented by the above formula (2).

(proportion of thermally dissociable soluble groups)

The dissociable group may also be contained in a portion other than the repeating unit of the above dissociable polymer. The dissociative group contained in the dissociable polymer chain is preferably 5 or more on average, more preferably 10 or more on average, and 50 or more on average.

In the above range, it is preferred to use an organic layer formed of a dissociable polymer to reduce the solubility of the organic solvent.

Hereinafter, preferred specific examples of the dissociable polymer of the present invention are as follows, but the present invention is not limited to these. Further, in the formula, n represents the number of repetitions of the repeating unit.

(crosslinking base)

Further, when the aromatic tertiary amine polymer compound of the present invention is a conjugated polymer, it is possible to cause a reaction (crosslinking reaction) before and after irradiation with heat and/or active energy rays. From the viewpoint that the solubility of the solvent is largely different, the insoluble group preferably has a crosslinkable group.

Here, the "crosslinking group" refers to a group which generates a novel chemical bond by irradiation with heat and/or an active energy ray and reacts with the same or different groups of molecules located in the vicinity.

The crosslinkable group is, for example, a group exemplified as the crosslinkable group T from the viewpoint of easy crosslinking.

<Crosslinking base group T>

(In the formula, R ⁸¹ to R ⁸⁵ each represents a hydrogen atom or an alkyl group which is independent of each other. Ar ⁴¹ represents an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent. The benzocyclobutene ring may have a substituent, and the substituents may be bonded to each other to form a ring.

From the viewpoint of high reactivity and easy insolubilization, a group such as a cyclic ether group such as an epoxy group or an oxetanyl group or a vinyl ether group which undergoes insolubilization reaction by cationic polymerization is preferable. Among them, from the viewpoint of easily controlling the rate of cationic polymerization, more preferred is oxetane The alkyl group is preferably a vinyl ether group from the viewpoint of less likely to form a hydroxyl group which may cause deterioration of the element when cationic polymerization is carried out.

From the viewpoint of further improving electrochemical stability, a group which undergoes a cycloaddition reaction such as an arylvinylcarbonyl group such as a cinnamyl group or a benzocyclobutene ring having one free valence is preferable.

Further, among the crosslinkable groups, a benzocyclobutene ring having one free valence is more preferable from the viewpoint of particularly stable structure after insolubilization.

Specifically, it is preferably a group represented by the following formula (5).

(The benzocyclobutene ring in the formula (5) may have a substituent. Further, the substituents may be bonded to each other to form a ring.)

The crosslinkable group may be directly bonded to an aromatic hydrocarbon ring group or an aromatic heterocyclic group in the molecule, or may be bonded via a divalent group. The divalent group is preferably a group selected from the -O- group, the -C(=O)- group or the -CH ₂ - group (which may also have a substituent), in any order, 1 to 30 The divalent group is bonded to an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Specific examples of the crosslinkable group via the above-mentioned divalent group, that is, the group containing a crosslinkable group are as shown in the following <base group T' containing a crosslinkable group, but the present invention is not limited to these. .

<Base group T containing crosslinkable group>

[化10]

[11]

(proportion of crosslinkable groups)

The crosslinkable group of the crosslinkable polymer of the present invention can be expressed by the number per 1000 molecular weight.

When the crosslinkable group of the crosslinkable polymer is represented by a number per 1000 molecular weight, it is usually 3.0 or less, preferably 2.0 or less, and more preferably 1000 per molecular weight. It is 1.0 or less, and is usually 0.01 or more, preferably 0.05 or more.

If it is within the above range, a flatter film can be obtained, and the unreacted crosslinkable group after film formation does not easily affect the driving life, which is preferable.

Here, the crosslinkable group of the crosslinkable polymer per 1000 molecular weight is obtained by subtracting the terminal group from the crosslinkable polymer, and calculating the molar ratio of the monomer charged during the synthesis, and the structural formula.

For example, description will be made based on the case of the following compounds.

In the above compound, the molecular weight of the repeating unit excluding the terminal group was 362.33 on average, and the crosslinkable matrix was 0.05 in average per repeating unit. If it is calculated in a simple ratio, the number of crosslinkable groups per molecular weight of 1,000 can be calculated to be 0.138.

Hereinafter, preferred specific examples of the crosslinkable polymer of the present invention are shown below, but the present invention is not limited to these.

[Specific example]

(In the above formula, for example, a = 0.475, b = 0.475, c = 0.025, and d = 0.025.)

[Chemistry 14]

(In the above formula, for example, a = 0.9 and b = 0.1.)

(In the above formula, for example, a = 0.94 and b = 0.06.)

(In the above formula, for example, a = 0.1 and b = 0.9.)

(In the above formula, for example, a = 0.9 and b = 0.1.)

[化18]

(In the above formula, for example, a = 0.1 and b = 0.9.)

(In the above formula, for example, a = 0.8, b = 0.1, and c = 0.1.)

(In the above formula, for example, a = 0.8 and b = 0.2.)

(In the above formula, for example, a = 0.2, b = 0.5, and c = 0.3.)

(In the above formula, for example, a = 0.9442 and b = 0.0558.)

(In the above formula, for example, a = 0.1 and b = 0.9.)

(In the above formula, for example, a = 0.9 and b = 0.1.)

(In the above formula, for example, a = 0.94 and b = 0.06.)

(In the above formula, for example, a = 0.9 and b = 0.1.)

(In the above formula, for example, a = 0.9 and b = 0.1.)

(extra good conjugated polymer having a crosslinkable group)

The crosslinkable polymer of the present invention has a high charge transporting ability and excellent redox stability, and particularly preferably: at least one repeating unit is selected from the group consisting of the following repeating unit group A, and A conjugated polymer in which at least one repeating unit is selected from the group consisting of repeating unit groups B.

<Repeating unit group A>

[化28]

<Repeating Unit Group B>

(glass transition temperature, other physical properties)

The glass transition temperature of the crosslinkable polymer of the present invention is usually 50° C. or higher, and is preferably 80° C. or higher, more preferably 100° C. or higher, from the viewpoint of driving stability including heat resistance of the organic electroluminescent device. Usually 300 ° C or less.

Further, the ionization potential of the conjugated polymer is usually 4.5 eV or more, preferably 4.8 eV or more, and usually 6.0 eV or less, from the viewpoint of excellent charge transport ability. The best is 5.7eV or less.

(Advantages of conjugated polymers having a crosslinkable group)

In the case of a solution for a charge transport film in a solution state, since it belongs to a solution, the molecular motion of the crosslinkable group is larger than that in a solid state. In this case, when the crosslinkable polymer is in a state of aggregation, when the crosslinkable groups are often kept in close proximity to each other, it is presumed that even if it is below the heating temperature for insolubilization, it will still depend on the moderate molecular motion. The probability of cross-linking in the condensed state is increased. In the case of a homogeneous solution which is not in agglomerated state, since the molecular motion of the molecule of the crosslinkable polymer itself is large, the crosslinkable groups do not always continue to exist close to each other, and therefore will be described below as a heating temperature for insolubilization. In the solution state, there is almost no possibility of crosslinking.

(related non-conjugated polymer)

The aromatic tertiary amine polymer compound of the present invention is preferably a non-conjugated polymer. The reason is that when the amine moiety is a cation radical by the electron acceptor compound, since the main chain is not conjugated, the cation radical does not easily move in a state where no voltage is applied. That is, the cationic radicals are uniformly distributed in the polymer chain. Therefore, it is preferred that the cationic radical propagates in the polymer chain and is less likely to cause aggregation due to localization of the polymer.

Among the non-conjugated polymers, the repeating unit represented by the above formula (2) is preferably contained, and the reason for the high transportability from the hole injection is that the repeating unit represented by the following formula (1) is preferably contained. molecule.

(In the formula (1), Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ³ to Ar ⁵ represent each a divalent aromatic hydrocarbon ring group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. In Ar ¹ to Ar ⁵ , a bond may also be bonded to the same N atom. The groups are bonded to each other to form a ring. The X system represents a divalent linking group.)

Ar ¹ to Ar ⁵ each represent an aromatic hydrocarbon ring group which may be independently substituted or an aromatic heterocyclic group which may have a substituent. These two groups, which may also be bonded on the same N atom, are bonded to each other to form a ring.

From the viewpoints of solubility, heat resistance, hole injection and transportability of the aromatic tertiary amine polymer compound, Ar ¹ and Ar ² are preferably each independently a one having a free valence of a substituent. The benzene ring, the naphthalene ring, the phenanthrene ring, the thiophene ring, and the pyridine ring are more preferably a phenyl group or a naphthyl group.

Further, Ar ³ to Ar ⁵ are preferably independently a benzene ring having two free valences, a naphthalene ring, and a stretching three from the viewpoint of hole injection and heat transportability including heat resistance and oxidation-reduction potential. A benzene ring or a phenanthrene ring is more preferably a phenyl group, a phenyl group, and a naphthyl group.

The aromatic hydrocarbon ring group of Ar ¹ to Ar ⁵ and the substituent which the aromatic heterocyclic group may have may be synonymous with the above-mentioned <substituent group Z>. Further, the preferred bases in the relevant ones are also the same.

The molecular weight of the substituent is usually 400 or less, and preferably 250 or less.

(linker X)

Further, in the repeating unit represented by the above formula (1), the linking group X is preferably a divalent linking group selected from the following <linking group group X'.

<connection base group X'>

(In the formula, Ar ¹¹ to Ar ²⁸ each independently represent an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ⁴¹ and R ⁴² each represent independently hydrogen. Atom or any substituent.)

Ar ¹¹ to Ar ²⁸ may be, for example, the same groups as described above for Ar ¹ to Ar ⁵ . R ⁴¹ and R ⁴² are a hydrogen atom or a substituent. When the substituent is exemplified, for example, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a decyl group, a decyloxy group, an aromatic hydrocarbon group or an aromatic heterocyclic group can be used. A preferred embodiment can be exemplified, for example, in the above <Substituent Group Z>.

The substituent which the aromatic hydrocarbon ring group and the aromatic heterocyclic group in Ar ¹¹ to Ar ²⁸ may have may be, for example, those exemplified in the above-mentioned <Substituent Group Z>.

In addition, the aromatic tertiary amine polymer compound used in the present invention is injected from a hole and has a very high transportability, and the above formula (1) is preferably a formula (1-1) or a better system. The following formula (1-2).

(In the formula (1-1), R ¹ to R ⁵ each represent a substituent which is independent of each other. p and q represent an integer of 0 to 5 which are independent of each other. r, s and t represent independent 0 to 4 Integer. The X system is synonymous with the formula (1).)

In the above formula (1-1), specific examples of R ¹ to R ⁵ may be those exemplified as the substituent group Z which may be possessed by the above Ar ¹ to Ar ⁵ .

Then, in the case of the formula (1-1), in the case where R ¹ to R ⁵ are plural, each of R ¹ to R ⁵ may be the same or different from each other.

(wherein Y represents a linking group selected from the following linking group X".)

<Connection base group X">

(In the formula, Ar ¹¹ to Ar ¹⁷ each independently represent an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent.)

The Ar ¹¹ to Ar ¹⁷ system may be, for example, the same groups as the above Ar ¹ to Ar ⁵ , and preferred examples are also the same.

(Specific example of repeating unit of aromatic tertiary amine polymer compound)

Hereinafter, preferred examples of the repeating unit constituting the aromatic tertiary amine polymer compound of the present invention are exemplified, but the present invention is not limited thereto.

[化36]

In the above specific examples, from the viewpoints of heat resistance and charge transporting ability, P-1 to P-11, P-13 to P-18, P-20, P-21, P-23, and P-25 are preferred. , repeating unit of P-26, more preferably repeating units of P-1, P-3, P-4, P-6, P-9, P-10, especially good P-1~P-11, P -13~P-18, P-20, P-21, P-23, P-25, P-26 repeating units, and more preferably P-1, P-3, P-4, P-6, The repeating unit of P-9 and P-10 is preferably a repeating unit of P-1 and P-4.

The aromatic tertiary amine polymer compound of the present invention may be a polymer containing two or more different repeating units.

Further, Ar ¹ to Ar ⁵ or the linking group X in the repeating unit represented by the formula (1) may be different and may be different repeating units.

In the composition for an organic electroluminescence device of the present invention, the content of the aromatic tertiary amine polymer compound is usually 1% by weight or more, preferably 2% by weight or more, and usually 6 wt% or less, preferably 5% by weight or less. If the content of the aromatic tertiary amine polymer compound is too small, the charge transporting ability may be insufficient. Further, if the amount is too large, the solubility of the aromatic tertiary amine polymer compound in the organic solvent may be lowered. When two or more different aromatic tertiary amine polymer compounds are used in combination, the total content of these is included in the above range.

<Electron acceptor compound>

The "electron acceptor compound" preferably has an oxidizing power and has a compound capable of accepting an electron from the transporting compound into the transporting hole, and particularly preferably a compound having an electron affinity of 4 eV or more, more preferably 5 eV. The above compounds.

Such an electron acceptor compound can be, for example, a group consisting of a triarylboron compound, a metal halide, a Lewis acid, an organic acid, a phosphonium salt, a salt of an arylamine and a metal halide, a salt of an arylamine and a Lewis acid. One or two or more compounds are selected from the group.

The electron acceptor compound contained in the composition for an organic electroluminescence device of the present invention preferably has a long period type periodic table (hereinafter, unless otherwise stated, the term "periodic table" is used to mean In the elements of Groups 15 to 17 of the periodic periodic table, an ionic compound having a structure in which at least one organic group is bonded by a carbon atom is more preferably one of the following formulas (I-1) to (I-3). The compound shown.

[化37]

In the formulae (I-1) to (I-3), R ⁵¹ , R ⁶¹ and R ⁷¹ each represent an organic group independently bonded to D ¹ to D ³ by a carbon atom; R ⁵² , R ⁶² and R ⁶³ and R ⁷² to R ⁷⁴ represent independent substituents. Two or more adjacent groups of R ⁵¹ to R ⁷⁴ may be bonded to each other to form a ring.

When R ⁵¹ , R ⁶¹ and R ⁷¹ are an organic group having a carbon atom at a bonding portion with D ¹ to D ³ , the type is not particularly limited unless it is impaired by the effects of the present invention. The term "organic group" as used in the present invention means a group containing at least one carbon atom.

The molecular weights of R ⁵¹ , R ⁶¹ and R ⁷¹ are usually in the range of 1,000 or less, preferably 500 or less, based on the value including the substituent. Preferred examples of R ⁵¹ , R ⁶¹ and R ⁷¹ include, for example, an alkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group from the viewpoint of making the positive charge non-localized. Among them, an aromatic hydrocarbon ring group or an aromatic heterocyclic group is preferred from the viewpoint of making the positive charge non-localized and thermally stable.

The aromatic hydrocarbon ring system is a monocyclic or 2 to 5 condensed ring having a free valence of five or six members, and for example, a positive charge can be a non-localized group on the group. Specific examples are, for example, a benzene ring having a free valence, a naphthalene ring, an anthracene ring, a phenanthrene ring, an anthracene ring, a tetrazene ring, an anthracene ring, a benzofluorene ring, Ring, extended triphenyl ring, anthracene ring, anthracene ring, and the like.

The aromatic heterocyclic group is a monocyclic or 2 to 4 condensed ring having a free valence of a five or six membered ring, and for example, a positive charge can be made to be a non-localized group on the group. Specific examples may be, for example, a furan ring having 1 free valence, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, a triazole ring, an imidazole ring, Diazole ring, anthracene ring, indazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, fluorinated pyrrole ring, fluorinated furan ring, thiophene Furan ring, benzopyrene Oxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyridyl Ring, 哒 Ring, pyrimidine ring, three Ring, quinoline ring, isoquinoline ring, Porphyrin ring, quinolin A porphyrin ring, a phenanthridine ring, a benzimidazole ring, an acridine ring, a quinazoline ring, a quinazolinone ring, an anthracene ring or the like.

The alkyl group may be, for example, a linear chain, a branched chain or a cyclic alkyl group, and the carbon number thereof is usually 1 or more, and usually 12 or less, preferably 6 or less. Specific examples may be, for example, methyl, ethyl, n-propyl, 2-propyl, n-butyl, isobutyl, tert-butyl, cyclohexyl and the like.

The alkenyl group may have, for example, a carbon number of usually 2 or more, and usually 12 or less, preferably 6 or less. Specific examples may be, for example, a vinyl group, an allyl group, a 1-butenyl group or the like.

The alkynyl group may, for example, have a carbon number of usually 2 or more, and usually 12 or less, preferably 6 or less. Specific examples may be, for example, an ethynyl group, a propynyl group or the like.

The types of R ⁵² , R ⁶² , R ⁶³ and R ⁷² to R ⁷⁴ are not particularly limited as long as they do not impair the effects of the present invention. The molecular weights of R ⁵² , R ⁶² , R ⁶³ and R ⁷² to R ⁷⁴ are usually in the range of 1,000 or less, preferably 500 or less, based on the value including the substituent. Examples of R ⁵² , R ⁶² , R ⁶³ and R ⁷² to R ⁷⁴ may, for example, be a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, an amine group or an alkoxy group. Base, aryloxy, fluorenyl, alkoxycarbonyl, aryloxycarbonyl, alkoxycarbonyl, alkylthio, arylthio, sulfonyl, alkanesulfonyl, arylsulfonyl, sulfonyloxy, cyanide Base, hydroxyl group, thiol group, decyl group, and the like. Among them, similarly to R ⁵¹ , R ⁶¹ and R ⁷¹ , from the viewpoint of a large electron acceptor property, an organic group having a carbon atom at a bonding portion with D ¹ to D ³ is preferred. For example, an alkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group. In particular, from the viewpoint of a large electron acceptor property and thermal stability, an aromatic hydrocarbon ring group or an aromatic heterocyclic group is preferred.

The alkyl group, the alkenyl group, the alkynyl group, the aromatic hydrocarbon ring group, and the aromatic heterocyclic group may be the same as those described for the related R ⁵¹ , R ⁶¹ and R ³¹ , for example.

The amine group may be, for example, an alkylamino group, an arylamino group, a mercaptoamine group or the like.

The alkylamine group may, for example, be an alkylamine group having a carbon number of usually 1 or more, and usually 12 or less, preferably 6 or less, having 1 or more alkyl groups. Specific examples may be, for example, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamine group or the like.

The arylamine group may, for example, be an arylamine group having 1 or more carbon atoms, preferably 4 or more, and usually 25 or less, preferably 15 or less, having 1 or more aromatic hydrocarbon ring groups or aromatic heterocyclic groups. Specific examples may be, for example, an anilino group, a diphenylamino group, a toluidine group, a pyridylamino group, a thienyl group, and the like.

The mercaptoamine group may, for example, be a mercaptoamine group having a carbon number of usually 2 or more, usually 25 or less, preferably 15 or less, and having 1 or more mercapto groups. Specific examples may be, for example, an ethenylamino group, a benzhydrylamino group or the like.

The alkoxy group may, for example, be an alkoxy group having a carbon number of usually 1 or more, usually 12 or less, preferably 6 or less. Specific examples may be, for example, a methoxy group, an ethoxy group, a butoxy group or the like.

The aryloxy group may, for example, be an aryloxy group having an aromatic hydrocarbon ring group or an aromatic heterocyclic group having a carbon number of usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples may be, for example, a phenoxy group, a naphthyloxy group, a pyridyloxy group, a thienyloxy group or the like.

The fluorenyl group may, for example, be a fluorenyl group having a carbon number of usually 1 or more, usually 25 or less, preferably 15 or less. Specific examples may be, for example, a decyl group, an ethyl fluorenyl group, a benzamidine group or the like.

The alkoxycarbonyl group may, for example, be an alkoxycarbonyl group having a carbon number of usually 2 or more, usually 10 or less, preferably 7 or less. Specific examples may be, for example, a methoxycarbonyl group, an ethoxycarbonyl group or the like.

The aryloxycarbonyl group may have, for example, a carbon number of usually 3 or more, preferably 4 or more, and Usually, it is 25 or less, preferably 15 or less, which has an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Specific examples may be, for example, a phenoxycarbonyl group, a pyridyloxycarbonyl group or the like.

The alkoxycarbonyl group may, for example, be an alkylcarbonyloxy group having a carbon number of usually 2 or more, usually 10 or less, preferably 7 or less. Specific examples may include, for example, an ethenyloxy group, a trifluoroacetoxy group, and the like.

The alkylthio group may, for example, be an alkylthio group having a carbon number of usually 1 or more, usually 12 or less, preferably 6 or less. Specific examples may be, for example, a methylthio group, an ethylthio group or the like.

The arylthio group may, for example, be an arylthio group having a carbon number of usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 14 or less. Specific examples may be, for example, a phenylthio group, a naphthylthio group, a pyridylthio group or the like.

Specific examples of the alkanesulfonyl group and the arylsulfonyl group may be, for example, a methylsulfonyl group or a toluenesulfonyl group.

Specific examples of the sulfonyloxy group may be, for example, a methylsulfonyloxy group, a toluenesulfonyloxy group or the like.

Specific examples of the decyl group may be, for example, a trimethyldecyl group, a triphenyldecylalkyl group or the like.

The groups exemplified above for R ⁵¹ , R ⁶¹ , R ⁷¹ and R ⁵² , R ⁶² , R ⁶³ and R ⁷² to R ⁷⁴ may be further substituted by other substituents without departing from the gist of the present invention. . The type of the substituent is not particularly limited, and for example, in addition to the groups exemplified for the above R ⁵¹ , R ⁶¹ , R ⁷¹ and R ⁵² , R ⁶² , R ⁶³ and R ⁷² to R ⁷⁴ , For example, a halogen atom, a cyano group, a thiocyano group, a nitro group or the like. Among them, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, or an aromatic hydrocarbon ring is preferred from the viewpoint of not impeding the heat resistance and electron acceptability of the ionic compound (electron acceptor compound). Base, aromatic heterocyclic group.

In the formulae (I-1) to (I-3), D ¹ and D ² represent elements after the third cycle of the periodic table (specifically, the third to sixth cycles), and D ³ represents the second cycle of the periodic table. (specifically, the second to sixth cycles), D ¹ represents a Group 17 element of the long-period periodic table, D ² represents an element of Group 16, and D ³ represents an element of Group 15.

Among them, from the viewpoint of electron acceptability and ease of availability, elements before the fifth cycle of the periodic table are preferred. That is, D ^{1 is} preferably any one of an iodine atom, a bromine atom, and a chlorine atom, and D ^{2 is} preferably any one of a ruthenium atom, a selenium atom, and a sulfur atom, and D ^{3 is} preferably a ruthenium atom or an arsenic atom. Any one of a phosphorus atom and a nitrogen atom. Particularly, in terms of electron acceptor property and compound stability, D ¹ in the formula (I-1) is an electron acceptor compound of a bromine atom or an iodine atom, and D in the formula (I-2) ² is an electron acceptor compound of a selenium atom or a sulfur atom, and an electron acceptor compound wherein D ³ in the formula (I-3) is a nitrogen atom, and more preferably, D ¹ in the formula (I-1) is iodine. An electron accepting compound of an atom, and D ³ in the formula (I-3) is an electron accepting compound of a nitrogen atom.

In the formulae (I-1) to (I-3), Z ₁ ^n1- to Z ₃ ^n3- represent independent conjugated anions. The type of the conjugated anion is not particularly limited, and may be a monoatomic ion or a wrong ion. However, since the size of the conjugated anion is larger, the negative charge is more non-localized, and the positive charge is more non-localized, so that the electron acceptor capacity is increased, and thus the wrong ion is superior to the single atom ion.

n ₁ ~ n ₃ are independent of any positive integer corresponding to the conjugated anion Z ₁ ^n1- ~Z ₃ ^{n3-ionovalent} . The value of n ₁ to n ₃ is not particularly limited, and is preferably 1 or 2, more preferably 1.

Specific examples of Z ₁ ^n1- to Z ₃ ^n3- may be, for example, hydroxide ions, fluoride ions, chloride ions, bromide ions, iodide ions, cyanide ions, nitrate ions, nitrite ions , sulfate ion, sulfite ion, perchlorate ion, perbromate ion, periodate ion, chlorate ion, chlorite ion, hypochlorite ion, phosphate ion, phosphite ion, two Phosphate ion, borate ion, isocyanate ion, sulfur hydride ion, tetrafluoroborate ion, hexafluoroborate ion, hexafluorophosphate ion, hexachloroantimonate ion; acetate ion, trifluoroacetate a carboxylate ion such as an ion or a benzoate ion; a sulfonate ion such as a methanesulfonic acid or a trifluoromethanesulfonate ion; an alkoxy ion such as a methoxy ion or a third butoxy ion; and the like, preferably a tetrafluoroboric acid. Root ions and hexafluoroborate ions.

Further, the conjugated anion Z ₁ ⁿ¹ - to Z ₃ ⁿ³ is preferably one of the following formulas (I-4) to (I-6) from the viewpoints of stability of the compound and solubility in an organic solvent. The wrong ions are shown in the larger size point of view, because the negative charge is non-localized, and thus the positive charge is non-localized, and the electron acceptor capacity is increased, which is better (I-6). Wrong ions.

In the formulae (I-4) and (I-6), E ¹ and E ³ each represent a group 13 element of the long-period periodic table. In particular, a boron atom, an aluminum atom, and a gallium atom are preferred, and a boron atom is preferred from the viewpoints of stability of the compound, ease of synthesis, and purification.

In the formula (I-5), E ² represents a group 15 element of the long period type periodic table. Among them, a phosphorus atom, an arsenic atom, and a ruthenium atom are preferred, and a phosphorus atom is preferred from the viewpoints of ease of compound stability, synthesis and purification, and toxicity.

In the formulae (I-4) and (I-5), Q ₄ and Q ₆ represent a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom, and it is preferred from the viewpoints of stability, synthesis and purification of the compound. It is a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

In the formula (I-6), Ar ⁶¹ to Ar ⁶⁴ each represent an independent aromatic hydrocarbon ring group or an aromatic heterocyclic group. Examples of the aromatic hydrocarbon ring group and the aromatic heterocyclic group can be, for example, a single ring or a ring of five or six-membered rings having one free valence, similar to those exemplified in the above-mentioned related R ⁵¹ , R ⁶¹ and R ⁷¹ . ~4 condensed ring. Among them, from the viewpoint of stability of the compound and heat resistance, a benzene ring, a naphthalene ring, a pyridine ring, and a pyrene having one free valence are preferred. Ring, 哒 Ring, pyrimidine ring, three Ring, quinoline ring, isoquinoline ring.

The aromatic hydrocarbon ring group and the aromatic heterocyclic group exemplified in Ar ⁶¹ to Ar ⁶⁴ may be further substituted by other substituents without departing from the gist of the present invention. The kind of the substituent is not particularly limited, and any substituent may be applied, and an electrophilic group is preferred.

For exemplifying a preferred electrophilic group of a substituent which Ar ⁶¹ to Ar ⁶⁴ may have, for example, a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom; a cyano group; a thiocyano group; a nitro group; An alkanesulfonyl group such as a sulfonyl group; a sulfonyl group such as a toluenesulfonyl group; a fluorenyl group having a carbon number of usually 1 or more, usually 12 or less, preferably 6 or less, such as a fluorenyl group, an ethyl fluorenyl group or a benzamidine group; The number of carbon atoms such as an oxycarbonyl group or an ethoxycarbonyl group is usually 2 or more, usually 10 or less, preferably 7 or less, and the carbon number such as a phenoxycarbonyl group or a pyridyloxycarbonyl group is usually 3 or more, preferably 4 or more, and usually 25 or less. More preferably, the aryloxycarbonyl group having an aromatic hydrocarbon ring group or an aromatic heterocyclic group; an aminocarbonyl group; an aminosulfonyl group; a trifluoromethyl group or a pentafluoroethyl group having a carbon number of usually 1 or more; Usually, a linear, branched or cyclic alkyl group of 10 or less, preferably 6 or less, has a halogenated alkyl group substituted by a halogen atom such as a fluorine atom or a chlorine atom.

Among them, it is more preferred that at least one of Ar ⁶¹ to Ar ⁶⁴ has a fluorine atom or a chlorine atom as a substituent of 1 or more. In particular, from the viewpoint of making the negative charge efficiency non-localized and having moderate sublimation properties, a perfluoroaryl group in which all hydrogen atoms of Ar ⁶¹ to Ar ⁶⁴ are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroaryl group may be, for example, pentafluorophenyl, heptafluoro-2-naphthyl, tetrafluoro-4-pyridyl or the like.

The molecular weight of the electron accepting compound of the present invention is usually 100 or more, preferably It is 300 or more, more preferably 400 or more, and usually 5,000 or less, preferably 3,000 or less, more preferably 2,000 or less. If the molecular weight of the electron acceptor compound is too small, there is a possibility that the electron acceptor ability is lowered because the non-localization of the positive charge and the negative charge is insufficient. On the other hand, if the molecular weight of the electron acceptor compound is too large, there is an electron. The receptor compound itself constitutes the possibility of a charge transport disorder.

Specific examples of the electron acceptor compound of the present invention are as follows, but the present invention is not limited to these.

In the above specific examples, from the viewpoints of electron acceptability, heat resistance, and solubility in an organic solvent, A-1 to 48, A-54, A-55, A-60 to 62, and A-64 are preferred. 75, A-79~83, B-1~20, B-24, B-25, B-27, B-30~37, B-39~43, C-1~10, C-19~21, Compounds of C-25~27, C-30, C-31, D-15~28, more preferably A-1~9, A-12~15, A-17, A-19, A-24, A -29, A-31~33, A-36, A-37, A-65, A-66, A-69, A-80~82, B-1~3, B-5, B-7~10 , B-16, B-30, B-33, B-39, C-1~3, C-5, C-10, C-21, C-25, C-31, D-17~28 compounds , Particularly preferred are compounds of A-1~7, A-80, and D-21~24.

The method for producing the electron acceptor compound described above is not particularly limited, and it can be produced by various methods. For example, Chem. Rev., vol. 66, p. 243, 1966, and J. Org. Chem., Vol. 53, p. 5571, 1988, and the like.

The composition for an organic electroluminescence device of the present invention may contain any one of the above-described electron acceptor compounds, or may be contained in any combination or ratio. Further, two or more electron acceptor compounds conforming to any one of the formulae (I-1) to (I-3) may be combined, or a combination of the different formulas (I-1) to (I-3) may be combined. Two or more electron acceptor compounds.

In the composition for an organic electroluminescence device of the present invention, the electron acceptor compound is particularly preferably a compound represented by the following formula (3).

In the composition for an organic electroluminescence device of the present invention, the content of the electron acceptor compound is usually 0.1% by weight or more, preferably 1% by weight based on the value of the aromatic tertiary amine polymer compound. The above is usually 100% by weight or less, preferably 40% by weight or less. When the content rate of the electron acceptor compound is too small, the driving voltage may increase. On the other hand, if the content of the electron acceptor compound is too large, the film formability may be lowered. When two or more kinds of electron accepting compounds are used in combination, the total content of these is included in the above range.

2. Particles

In the hole injection/transport layer of the present invention, particles are dispersed. The particles preferably have less light absorption in the light-emitting wavelength region of the light-emitting element, and more preferably have no light absorbability.

‧Material

The dispersed particle system can be selected from metal oxides, composite oxides, and polymer materials.

The metal oxide may be, for example, titanium oxide, zinc oxide, cerium oxide, aluminum oxide, zirconium oxide, cerium oxide, tin oxide, copper oxide, silver oxide, iron oxide, cerium oxide, tungsten oxide, indium oxide, manganese oxide, oxidation. Vanadium, cerium oxide, barium titanate, barium titanate, and the like.

Further, the composite oxide may be, for example, indium-tin oxide (ITO), aluminum-zinc oxide (AZO), gallium-zinc oxide (GZO) or the like.

These are all known substances and are readily available. Moreover, the raw material, the production method, and the like are not particularly limited. At this time, the metal oxide particles may also be subjected to a surface treatment. The surface treatment method may be, for example, adding a surface treatment agent to the metal oxide particle powder, and performing uniform mixing using a ball mill, a bead mill, a kneading machine, or the like, or heat treatment, etc., to adsorb or chemically treat the surface treatment agent. A method of bonding to metal oxide particles or the like. The chemical species introduced by the surface treatment may be, for example, inorganic oxides such as aluminum hydroxide, cerium oxide, or zirconium oxide; organic acids such as stearic acid; inorganic acids such as phosphoric acid; and polyfluorene.

The polymer material may be, for example, an acrylic resin, a polystyrene resin, a polyurethane resin, a melamine resin or the like. The spherical particles of these polymer materials are commercially available and can be easily obtained. Since the present invention forms a hole injection/transport layer by a wet film formation method, it is more preferable to use a crosslinked polymer material which is excellent in solubility resistance to a dispersion medium.

The particle system of the polymer material can be, for example, a comprehensive function of the comprehensive research chemical system "Trademark name: Chemisnow", the product of the spheroidal microparticle polymer (trade name: Techpolymer) and Nissan Chemical Co., Ltd. "trade name: OPTBEADS", the same trademark Name: HYPERTECH", Toray (share) "trade name: TORAYPEARL".

‧Refractive index

The refractive index of the particles can be obtained regardless of whether the refractive index of the particles is higher or lower than the refractive index of the hole-injecting compound (about 1.65~1.7), but it can be used to obtain a hole with high scattering performance. The refractive index of the particles is preferably 0.05 or more, more preferably 0.10 or more, and particularly preferably 0.20 or more with respect to the refractive index of the transporting compound to be injected into the cavity. Moreover, when the refractive index of the hole injection/transport layer is higher than the refractive index of the light-emitting layer (about 1.7), there is no loss due to total reflection at the interface, so the hole is injected and the refraction of the transport layer is The higher the rate, the better. Therefore, the refractive index of the particles is preferably higher than the refractive index of the hole-transporting compound itself, and the refractive index of the particles is preferably 1.70 or more, more preferably 1.75 or more, more preferably 1.85 or more, and the best system is 2.00. the above. According to the above, the particles are particularly preferably titanium oxide, barium titanate, zinc oxide, zirconium oxide, cerium oxide, tin oxide, or ITO.

‧particle size

Generally, the fine particles are classified into primary particles which are considered to be unit particles from the geometrical appearance of the appearance, and secondary particles which are plural sets by the primary particles. The particles of the present invention may be either primary particles or secondary particles, and the particles have an average particle diameter of 10 nm to 300 nm, preferably 50 to 250 nm, more preferably 100 to 200 nm. By using particles having an average particle diameter in such a range, it is possible to obtain an excellent surface flatness hole injection/transport layer having excellent scattering performance and no short-circuit of the organic electroluminescent element.

Further, the average particle diameter of the present invention is a value measured in accordance with a dynamic light scattering method.

‧ particle dispersion method

In the present invention, particles may be mixed alone or two or more kinds of particles may be mixed in the hole injection/transport layer forming composition.

The mixing ratio of the hole injecting the transporting compound to the particles is not particularly limited and can be arbitrarily selected. The solid weight of the transporting compound and the particles is preferably 95:5~20:80, better 90:10~25:75, and 80:20~30:70. If the solid weight ratio of the particles is 5 or more, sufficient scattering performance can be obtained, and if it is 80 or less, the hole can be injected into the ‧ transport layer to have sufficient conductivity. The surface of the particles or the surface portion of the primary particles contained in the secondary particles may be coated with a dispersing agent. In this case, the "weight of the particles" may also include the weight of the dispersing agent covering the particles.

Further, when mixing, the particles may be mixed in a powder form and dispersed, or may be dispersed in a suitable solvent before being mixed in the form of a particle dispersion. From the viewpoint of being able to be easily mixed and dispersed with the hole injection and the transport layer forming composition, it is preferred to carry out the method of mixing before the particle dispersion liquid is formed in advance.

The preparation method of the particle dispersion liquid is generally prepared by mixing a solvent and a particle, and if necessary, a dispersing agent and a ball for pulverization, in a form of a concentration of 5 to 70% by weight in advance, and dispersing the particles to prepare a particle dispersion. liquid. The dispersion treatment method may also use, for example, a dispersion treatment using an ultrasonic disperser; using a sand mill, an attritor, a bead mill, a bead mill, a ball mill, a fluidizer, a high speed mixer Any method such as a dispersion method by a homogenizer, a paint shaker, or the like.

In order to enhance the dispersion stability of the particles, it is usually possible to contain a low molecular dispersant or a polymer dispersant which is commercially available as a dispersant. Especially from the hole injection ‧ transport layer From the viewpoint of particle dispersion stability in the composition for forming, it is preferred to incorporate a polymer dispersant.

The polymer dispersant may be, for example, an urethane dispersant, a polyethylenimine dispersant, a polyoxyethylene alkyl ether dispersant, a polyethylene oxide diester dispersant, or a sorbitan fat. A family ester dispersant, an aliphatic modified polyester dispersant, and the like. These dispersing agents may be used alone or in combination of two or more. When the dispersant is contained, the content of the dispersant to the particles is preferably from 0.1 to 50% by weight, more preferably from 0.5 to 35% by weight, particularly preferably from 1 to 30% by weight, most preferably from 2 to 25 weight%. If the content of the dispersant to the particles is less than 0.1% by weight, the dispersion stability of the particles in the dispersion may be deteriorated; conversely, if it exceeds 50% by weight, the hole may be injected into the transport layer. The possibility of a reduction in hole mobility.

Further, a dispersing agent which causes the aforementioned cationic radical compound to be unstable may not be used. For example, a system for performing cationic radical radicalization using 4-isopropyl-4-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate for an aromatic tertiary amine polymer compound, if used together with an amine group or ammonium The cationic radical dispersant immediately causes the cationic radical to disappear, causing a decrease in the conductivity of the hole injection and the transport layer, resulting in an adverse effect of an increase in the driving voltage of the organic electroluminescent element.

3. Wet film forming method

When a hole injection/transport layer is formed by a wet film formation method, a material containing a hole injection layer and a transport layer (that is, a hole injecting a transport compound of the present invention) and a material of a particle are usually dissolved or The dispersed solvent (hole injection, solvent for the transport layer) is mixed to prepare a film-forming composition (hole injection/transport layer formation composition), and the hole is injected into the ‧ transport layer-forming composition The film is formed on a layer (usually an anode) corresponding to the lower layer of the hole injection layer, and is formed by drying. In addition, when a hole is injected into the transport layer, When a layer containing no particles is formed, layer formation can also be carried out by a suitably known vapor deposition method.

The hole injection ‧ the concentration of the transportable compound injected into the transport layer forming composition, and the total solid concentration of the hole injection transporting compound and the particles can be arbitrarily removed without significantly impairing the effects of the present invention. From the viewpoint of film thickness uniformity, the lower the better, and on the other hand, from the viewpoint that the hole injection and the transport layer are less likely to cause defects, and the fact that a thick film is easily obtained, the higher the better. Specifically, it is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and particularly preferably 0.5% by weight or more, and on the other hand, preferably 70% by weight or less, more preferably 60% by weight or less. It is preferably 50% by weight or less.

The film thickness of the hole injection/transport layer of the present invention is 100 nm or more and 1000 nm or less. Compared with the hole injection of the general organic electric field element, the transport layer is thicker under tens of nm, but the invention is characterized in that the film thickness can be formed by single coating or repeated coating can be repeated. And formed.

When formed by overlapping coating, the hole injection-transporting compound preferably has a crosslinkable group. In the case of having a crosslinkable group, the heat-transfer coating is applied, and the transporting compound is injected into the hole to improve the solvent resistance. Therefore, even if the composition for forming a hole injection layer is overlaid, the formation is completed. The film is also not reduced by dissolution, and the film thickness is effectively increased. Further, by performing cross-linking, the particles are fixed in the coating film in a uniformly dispersed state, so that it is possible to avoid the problem that the particles are agglomerated with each other and phase-separated with the transporting compound into the hole.

It is also possible to superimpose a hole injection ‧ transport layer forming composition which does not contain particles on a hole injection/transport layer containing particles. Although the hole containing the particles is injected and the transport layer may have poor surface flatness, the surface flatness of the hole injection and the transport layer can be improved by this method, and it is also expected to be improved with the hole transport layer or the light-emitting layer. Adjacency table The effect of the hole injection performance near the surface.

The hole injection and the solvent for forming the transport layer can be selected from those in which a transportable compound can be injected into a dissolved cavity and the particles can be stably dispersed.

When a pre-modulated particle dispersion liquid and a solution in which a hole is injected into a transporting compound are mixed to prepare a hole injection/transport layer forming composition, the hole is injected and the transport layer forming composition is preserved. From the viewpoint of stability, it is preferred that the particle dispersion is the same solvent type as the solution for injecting the transport compound into the cavity. The solvent may be, for example, an ether solvent, an ester solvent, an aromatic hydrocarbon solvent or a guanamine solvent.

The ether solvent may, for example, be an aliphatic ether such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether or propylene glycol-1-monomethyl ether acetate (PGMEA), or 1,2-dimethoxybenzene or 1, 3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-di An aromatic ether such as methyl anisole or the like.

The ester solvent may, for example, be an aromatic ester such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate or n-butyl benzoate.

The aromatic hydrocarbon solvent may be, for example, toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene or a ring. Hexabenzene, methylnaphthalene, and the like. The guanamine-based solvent may, for example, be N,N-dimethylformamide or N,N-dimethylacetamide.

In addition to these, it is also possible to use dimethyl hydrazine or the like.

In the general wet film formation method, the coating liquid is applied to the coating after being filtered by a filtration filter to remove fine dust and insoluble matter. However, since the hole injection/transport layer forming composition of the present invention contains the coating liquid of the particles, the composition does not pass according to the opening diameter of the filter filter. In this case, it is preferred to inject the dispersion of the particle dispersion and the hole into the solution of the transporting compound, respectively, by filtering with a suitable filter for opening pore size filtration, and then mixing to prepare a hole injection and a transport layer shape. A method of using a composition.

In addition, the viscosity of the composition for forming the hole and the layer for transporting the layer is about 0.5 mPa·s to 500 mPa·s from the viewpoint of coatability. Further, in the composition, an additive such as a surfactant, a flow regulating agent, or an antifoaming agent may be mixed as needed within a range in which the performance of the organic electroluminescent device is not caused to occur.

Hole injection ‧ The transport layer is formed by the wet film formation method, usually after the hole is injected into the ‧ transport layer forming composition, and then coated into a film under the hole injection ‧ transport layer The layer (usually an anode) is applied by drying.

Hole injection ‧ The transport layer is usually dried after being formed into a film by heating, drying under reduced pressure, or the like.

In addition, the hole injection ‧ transport layer can also be cross-linked.

The coating method may be, for example, spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, nozzle coating, ink jetting. A known method such as a method, a screen printing method, a gravure printing method, or a quick-drying printing method. From the viewpoint of obtaining surface flatness more easily and simply, a spin coating method, a die coating method, and a dip coating method are preferred.

In particular, when an aromatic amine is used, since the aromatic amine absorbs light, the film thickness is generally not set to 100 nm or more. However, the present inventors have found that when particles are dispersed in an aromatic amine, the film thickness is set to be 100 nm or more, and the light extraction efficiency can be unexpectedly improved.

4. Organic electric field light-emitting element

Hereinafter, an embodiment of an organic electroluminescence device, an organic EL display device, and an organic EL illumination device including the hole injection/transport layer of the present invention will be described in detail, but the present invention is not in the scope of the purpose of the present invention. These contents are limited.

(substrate)

The substrate is a support for the organic electroluminescent device, and for example, a plate made of quartz or glass, a metal plate, a metal foil, a plastic film (or a sheet), or the like is used. Among these, a plate of a transparent synthetic resin such as a glass plate, a polyester, a polymethacrylate, a polycarbonate or a polyfluorene is preferred. The substrate system is preferably a material having high gas barrier properties from the viewpoint that it is less likely to cause deterioration of the organic electric field light-emitting element due to external air. Therefore, in particular, when a material having a low gas barrier property such as a synthetic resin substrate is used, it is preferable to design a dense tantalum oxide film or the like on at least one side of the substrate to improve gas barrier properties.

(anode)

The anode is responsible for the function of injecting holes into the layer on the side of the light-emitting layer. The anode is usually made of a metal such as aluminum, gold, silver, nickel, palladium or platinum; a metal oxide such as an oxide of indium and/or tin; a halogenated metal such as copper iodide; carbon black and poly(3-methylthiophene). ), a conductive polymer such as polypyrrole or polyaniline, and the like. The formation of the anode is usually carried out by a dry method such as a sputtering method or a vacuum deposition method. In addition, when an anode is formed using, for example, metal fine particles such as silver or fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, or conductive polymer fine powder, it is dispersed in a suitable binder resin solution. It can also be formed by applying it to a substrate. Further, in the case of a conductive polymer, a thin film may be directly formed on a substrate by electrolytic polymerization, or a conductive polymer may be applied onto the substrate to form an anode (Appl. Phys. Lett., Vol. 60, p. 2711) ,1992).

The anode usually has a single layer structure, but a laminated structure can also be formed as appropriate. In the case of an anode laminated structure, different conductive materials may be laminated on the first layer anode. The thickness of the anode can be determined by matching the necessary transparency and material. In particular, when high transparency is required, it is preferred that the visible light transmittance is 60% or more. The thickness is more than 80% of the thickness. The thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, when transparency is not required, the thickness of the anode may be arbitrarily set to a thickness in accordance with necessary strength, and in this case, the anode may be formed to have the same thickness as the substrate.

When film formation is performed on the surface of the anode, it is preferable to remove impurities on the anode by adjusting ultraviolet rays, ozone, oxygen plasma, argon plasma, etc. before the film formation, and adjust the ionization potential to increase the electricity. Hole injection.

(lighting layer)

The light-emitting layer is a layer that is responsible for the function of light emission by recombining a hole injected from the anode and electrons injected from the cathode when an electric field is applied between the pair of electrodes. The luminescent layer is a layer formed between the anode and the cathode, and the luminescent layer is formed between the hole injection ‧ the transport layer and the cathode when the hole is injected into the anode and the transport layer is formed on the anode The case of the hole transport layer is formed between the hole transport layer and the cathode.

The film thickness of the light-emitting layer may be arbitrarily removed without significantly impairing the effects of the present invention, but from the viewpoint that the film is less likely to be defective, the thicker the better, and on the other hand, from the viewpoint of easily forming a low driving voltage. The thinner the better. Therefore, it is preferably 3 nm or more, more preferably 5 nm or more, and on the other hand, it is usually preferably 200 nm or less, more preferably 100 nm or less.

The light-emitting layer contains at least a material having a light-emitting property (light-emitting material), and preferably a material having a charge transport property (charge transporting material).

(Luminescent material)

The luminescent material emits light according to a desired luminescent wavelength, and is not particularly limited as long as it does not impair the effects of the present invention, and a known luminescent material can be used. The luminescent material may be a fluorescent luminescent material or a phosphorescent luminescent material, and is preferably a material having good luminous efficiency. The viewpoint of internal quantum efficiency is preferably a phosphorescent material.

The fluorescent material can be, for example, the following materials.

The fluorescent material (blue fluorescent material) imparting blue light emission may be, for example, naphthalene, anthracene, anthracene, anthracene, coumarin, , p-bis(2-phenylvinyl)benzene, and the like.

The fluorescent material (green fluorescent material) to which green light is emitted may be, for example, a quinophthalone derivative, a coumarin derivative, an aluminum complex such as Al(C ₉ H ₆ NO) ₃ or the like.

A fluorescent material (yellow fluorescent material) that imparts yellow light emission may be, for example, rubrene, an acridone derivative or the like.

A fluorescent material (red fluorescent material) that imparts red light emission can be, for example, DCM [4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran,4-(dicyanic acid) 2-methyl-6-(4-dimethylamino-styrene)-4H-pyran] compound, benzopyran derivative, Rhodamine derivative, benzo sulfur Derivative, azabenzo sulfur (azabenzothioxantene) and the like.

Further, the phosphorescent material may, for example, contain an organometallic complex or the like of a metal selected from Groups 7 to 11 of the long-period periodic table. The metal selected from Groups 7 to 11 of the periodic table may preferably be, for example, ruthenium, rhodium, palladium, silver, rhodium, iridium, iridium, platinum, gold or the like.

The ligand of the organometallic complex, preferably a (hetero)arylpyridine ligand, a (hetero)arylpyrazole ligand, etc., from a (hetero)aryl group, and such as pyridine, pyrazole, phenanthrene The ligand to which the porphyrin or the like is bonded is more preferably a phenylpyridine ligand or a phenylpyrazole ligand. The "(hetero)aryl group" herein means an aryl group or a heteroaryl group.

Preferred phosphorescent materials are, for example, tris(2-phenylpyridine)fluorene, tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum. a phenylpyridine complex such as tris(2-phenylpyridine)anthracene or tris(2-phenylpyridinium)anthracene, and octaethylporphyrin platinum, a porphyrin complex such as octaphenylporphyrin platinum, octaethylporphyrin palladium, octaphenylporphyrin palladium or the like.

The polymer light-emitting material can be, for example, poly(9,9-dioctylfluorene-2,7-diyl), poly[(9,9-dioctylfluorene-2,7-diyl)-co- (4,4'-(N-(4-Self-butylphenyl))diphenylamine)], poly[(9,9-dioctylfluoren-2,7-diyl)-co-( a polyfluorene-based material such as 1,4-benzo-2(2,1'-3}-triazole)]; poly[2-methoxy-5-(2-ethylhexyloxy)-1,4 - phenylene vinylene] and other styrene-based materials.

(charge transport material)

The charge transporting material is a material having a positive electric charge (hole) or a negative electric charge (electron) transporting property, and is not particularly limited as long as it does not impair the effects of the present invention, and a known luminescent material can be used.

As the charge transporting material, a compound or the like which is conventionally used for the light-emitting layer of the organic electroluminescent device can be used, and a compound which is used as a main material of the light-emitting layer is particularly preferable.

The charge transporting material may specifically be, for example, an aromatic amine compound, a phthalocyanine compound, a porphyrin compound, an oligothiophene compound, a polythiophene compound, or a benzylphenyl compound, and a tertiary amine is bonded to the thiol group. a compound, an anthraquinone compound, a guanidine compound, a decylamine compound, a phosphonium compound, a quinophthalone compound, etc., are used as an exemplary compound used for injection of a transporting compound into a cavity of a hole injection/transport layer. Further, for example, an anthraquinone compound, an anthraquinone compound, an oxazole compound, a pyridine compound, or a phenanthroline compound, An electron transporting compound such as a bisazole compound or a silole compound or the like.

Further, it is preferred to use, for example, a 4,4'-bis[N-(1-naphthyl)-N-anilino]biphenyl group, which contains two or more tertiary amines and two or more condensations. An aromatic diamine in which an aromatic ring is substituted with a nitrogen atom (Japanese Patent Laid-Open No. Hei 5-234681); 4,4',4"-tris(1-naphthylanilino)triphenylamine has a star burst Aromatic amine compound of the formula (J. Lumin., vol. 72-74, p. 985, 1997); an aromatic amine compound composed of a tetramer of triphenylamine (Chem. Commun. , p. 2175, 1996); lanthanide compounds such as 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirobifluorene (Synth.Metals, Vol. 91, 209) (1997); an oxazole-based compound such as 4,4'-N, N'-dicarbazolebiphenyl or the like, which is exemplified as a hole injecting a transporting compound into a hole transporting layer, and the like. Further, for example, 2-(4-biphenyl)-5-(p-t-butylphenyl)-1,3,4- Diazole (tBu-PBD), 2,5-bis(1-naphthyl)-1,3,4- Diazole (BND), etc. Diazole compound; 2,5-bis(6'-(2',2"-bibipyridine))-1,1-dimethyl-3,4-diphenylnonol (PyPySPyPy) Noroline compound; phenanthroline compound such as phenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, batholine) and many more.

<Light-emitting layer formation by wet film formation method>

The method for forming the light-emitting layer may be a vacuum deposition method or a wet film formation method, and from the viewpoint of excellent film formability, a wet film formation method, a better spin coating method, and an ink jet method are preferred. . When the light-emitting layer is formed by the wet film formation method, it is usually the same as the case where the hole injection/transport layer is formed by the wet film formation method, and the composition for forming the transport layer is replaced by the hole injection. The material of the light-emitting layer and the solvent (the solvent for the light-emitting layer) which can be dissolved therein are mixed, and the composition for forming a light-emitting layer can be formed.

The solvent may be, for example, a related hole injection, an ether solvent, an ester solvent, an aromatic hydrocarbon solvent or a guanamine solvent, which may be exemplified by a transport layer, and may be, for example, an alkane solvent or a halogenated aromatic hydrocarbon solvent. An aliphatic alcohol solvent, an alicyclic alcohol solvent, an aliphatic ketone solvent, and an alicyclic ketone solvent. Specific examples of the solvent are given below, but are not limited to those before the effect of the present invention is impaired.

For example: an aliphatic ether solvent such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether or propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethyl Oxybenzene, anisole, phenylethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole An aromatic ether solvent such as diphenyl ether; an aromatic ester such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, ethyl benzoate, propyl benzoate or n-butyl benzoate; Solvent; toluene, xylene, mesitylene, cyclohexylbenzene, tetrahydronaphthalene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, An aromatic hydrocarbon solvent such as cyclohexylbenzene or methylnaphthalene; a guanamine solvent such as N,N-dimethylformamide or N,N-dimethylacetamide; n-decane, cyclohexane, and ethyl An alkane solvent such as cyclohexane, decalin or bicyclohexane; a halogenated aromatic hydrocarbon solvent such as chlorinated benzene, dichlorobenzene or trichlorobenzene; or an aliphatic alcohol solvent such as butanol or hexanol; An alicyclic alcohol solvent such as cyclohexanol or cyclooctanol; a lipid such as methyl ethyl ketone or dibutyl ketone Aliphatic ketone solvent; cyclohexanone, cyclooctanone, fenchone alicyclic ketone solvents and the like. Among these, an alkane type solvent and an aromatic hydrocarbon type solvent are preferable.

(hole blocking layer)

A hole blocking layer may be provided between the light emitting layer and an electron injecting layer to be described later. The hole blocking layer is a layer laminated on the light-emitting layer so as to be adjacent to the interface of the light-emitting layer on the cathode side.

The hole blocking layer has a function of preventing a hole moved from the anode from reaching the cathode, and a function of efficiently transporting electrons injected from the cathode toward the light emitting layer. The physical properties of the material constituting the hole blocking layer are, for example, high electron mobility, low hole mobility, large energy gap (difference in HOMO and LUMO), and high excitation triplet energy level (T1).

The material of the hole stop layer satisfying such conditions may be, for example, bis(2-methyl-8-quinolinyl)(phenol) aluminum, bis(2-methyl-8-quinolinyl) (triphenyl) Mixed ligand complex such as hydrazinyl)aluminum; bis(2-methyl-8-quinolinyl)aluminum- μ -oxy-bis-(2-methyl-8-quinolinyl)aluminum a metal complex such as a dinuclear metal complex; a styryl compound such as a stilbene biphenyl derivative (Japanese Patent Laid-Open No. Hei 11-242996); 3-(4-biphenyl)-4-phenyl a triazole derivative such as -5 (4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Laid-Open No. Hei 7-41759); phenanthroline derivative such as batholine (Japanese Patent) Japanese Patent Laid-Open No. Hei 10-79297, and the like. Further, a compound having at least one of the 2, 4, and 6 substituted pyridine rings described in International Publication No. 2005/022962 is also a preferred material for the hole blocking layer.

The method of forming the hole blocking layer is not limited. Therefore, it can be formed by a wet film formation method, a vapor deposition method, or the like.

The film thickness of the hole blocking layer may be any thickness before the effect of the present invention is not significantly impaired, and is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

(electron transport layer)

The electron transport layer is disposed between the light emitting layer and the electron injecting layer for the purpose of further improving the current efficiency of the element.

The electron transport layer is formed by a compound which can transport electrons injected from the cathode to the light-emitting layer in a direction in which an electric field can be applied. The electron transporting compound used in the electron transporting layer is required to have a high electron injection efficiency from the cathode or the electron injecting layer and a high electron mobility to efficiently transport the injected electrons.

The electron transporting compound used in the electron transporting layer is usually preferably a compound having high electron injection efficiency from the cathode or the electron injecting layer and capable of transporting the injected electrons efficiently. The electron transporting compound may be, for example, a metal complex such as an aluminum complex of 8-hydroxyquinoline (Japanese Patent Laid-Open Publication No. SHO 59-194393); a metal complex of 10-hydroxybenzo[h]quinoline Compound Diazole derivatives, stilbene biphenyl derivatives, indole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzo Oxazole metal complex, benzothiazole metal complex, tribenzimidazole benzene (US Patent No. 5645948), quin A porphyrin compound (Japanese Patent Laid-Open No. Hei 6-207169), a phenanthroline derivative (Japanese Patent Laid-Open No. Hei 5-331459), 2-tert-butyl-9,10-N,N'-dicyano group Diimine, n-type hydrogenated amorphous tantalum carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

The film thickness of the electron transport layer is usually 1 nm or more, preferably 5 nm or more, and on the other hand, usually 300 nm or less, preferably 100 nm or less.

The electron transport layer can be formed by laminating on the hole blocking layer by a wet film formation method or a vacuum deposition method in the same manner as described above. Vacuum evaporation is usually used.

(electron injection layer)

The electron injecting layer has a function of efficiently injecting electrons injected from the cathode into the electron transporting layer or the light emitting layer.

When electron injection is performed with high efficiency, the material forming the electron injecting layer is preferably a metal having a low work function. For example, an alkali metal such as sodium or cesium; an alkaline earth metal such as barium or calcium, or the like can be used. The film thickness is usually preferably 0.1 nm or more and 5 nm or less.

Further, by doping such as sodium in an organic electron transporting material represented by a metal complex such as a nitrogen-containing heterocyclic compound such as phenanthroline or an aluminum complex of 8-hydroxyquinoline, An alkali metal such as potassium, lanthanum, lithium, or lanthanum (described in Japanese Patent Laid-Open No. Hei 10-270171, JP-A-2002-100478, JP-A-2002-100482, and the like) can also enhance electron injection. ‧ It is preferred to have good transportability and excellent film quality.

The film thickness is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injecting layer can be formed by laminating the light emitting layer or the hole blocking layer on the light emitting layer by a wet film forming method or a vacuum vapor deposition method.

The details of the wet film formation method are the same as those of the above-mentioned light-emitting layer.

(cathode)

The cathode system functions to inject electrons into a layer (electron injection layer, light-emitting layer, or the like) on the side of the light-emitting layer.

The material of the cathode may be a material used for the above anode, and it is preferable to use a metal having a low work function under the premise of performing electron injection with high efficiency, and for example, a metal such as tin, magnesium, indium, calcium, aluminum or silver can be used. Or such alloys and the like. Specific examples are, for example, alloy electrodes of low work function such as magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy, and the like.

From the viewpoint of component stability, it is preferable to laminate a metal layer having a high work function and a stable atmosphere to the cathode, and to protect a cathode composed of a low work function metal. The metal layer to be laminated may be, for example, a metal such as aluminum, silver, copper, nickel, chromium, gold or platinum.

The film thickness of the cathode is usually the same as that of the anode.

(other layers)

The organic electroluminescent device of the present invention may be further provided without further obscuring the effects of the present invention, and may further be provided with other layers. That is, any other layer described above may be provided between the anode and the cathode.

<Other components>

Alternatively, the reverse structure described above may be formed, and the substrate may be laminated in the order of the cathode, the electron injection layer, the light-emitting layer, the hole injection, the transport layer, and the anode.

<Other>

When the organic electroluminescent device of the present invention is used in an organic electric field light-emitting device, it may be used as a single organic electroluminescent device, or in a configuration in which a plurality of organic electroluminescent devices are arranged in an array, or an anode and a cathode may be used. The configuration is arranged in an XY matrix.

5. Organic EL display device

The organic EL display device of the present invention can use the above-described organic electroluminescent device of the present invention. The type and structure of the organic EL display device of the present invention are not particularly limited, and the organic electroluminescent device of the present invention can be assembled in accordance with a conventional method.

For example, the organic EL display device of the present invention can be formed in accordance with the method described in "Organic EL Display" (Ohm Corporation, published on August 20, 2006, at the time of Shimoishi, Anda Chiba, and Murata Yuki).

6. Organic EL lighting

The organic EL illumination of the present invention uses the above-described organic electroluminescent device of the present invention. The type and structure of the organic EL illumination of the present invention are not particularly limited, and the organic electroluminescence device of the present invention can be assembled in accordance with a conventional method.

[Examples]

Hereinafter, the present invention will be described in more detail by way of Production Examples, Examples and Comparative Examples. However, the present invention is not limited to the following examples. In addition, the various manufacturing conditions and evaluation result values of the following examples have preferred values of the upper limit or the lower limit of the embodiment of the present invention, and the preferred range may also be the above upper or lower limit, and the following embodiment values. Or a range specified by the combination of values of the embodiments.

1. Determination of particle size of scattering particle dispersion

The average particle diameter of the scattering particle dispersion was measured using a thick particle size analyzer (FPAR-1000 type, dynamic light scattering method) manufactured by Otsuka Electronics Co., Ltd.

2. Determination of film thickness and surface roughness Ra

The film thickness of the hole injection layer was measured using a gradient ‧ surface roughness ‧ fine shape measuring device ("P-15 type") manufactured by KLA-Tencor Japan Co., Ltd. The surface roughness was measured as the arithmetic mean roughness Ra between 2000 μm.

<Example 1> 1. Production of organic electric field light-emitting elements 1) Production of organic electric field light-emitting element (A1) of the present invention <Modulation of Particle Dispersion 1>

In a glass bottle with a lid of 30 ml, 1.20 g of titanium oxide powder "TTO-55 (C)" (average primary particle size: 30 to 50 nm) made of Ishihara Sho (for the use of particles) was charged with benzoic acid B. Ester (ethyl benzoate, hereinafter referred to as "EB") 4.74g, BYK chemical dispersant "DISPERBYK-111" 0.12g, and 0.5mm 20 g of zirconium dioxide beads were sealed and swayed by a shallow field iron paint oscillating machine (PC type) for 4 hours to perform dispersion treatment. The dispersion was filtered using a 200 mesh mesh, and the zirconium dioxide beads were removed to obtain a particle dispersion 1. The average particle diameter of the dispersion was 166 nm.

<Modulation of the hole injection transporting composition 1>

The hole having the repeating unit shown below is injected into the transporting compound (HIL-1) and 4-isopropyl-4-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate by weight ratio. 100:20 The mixture was mixed, and ethyl benzoate was added so that the concentration of the mixture became 5.0% by weight, and the hole was injected into the transporting composition 1 by heating.

<Modulation of coating solution for hole injection layer>

A particle dispersion 1 (0.33 g), a hole injection-transporting composition 1 (1.40 g), and 0.93 g of ethyl benzoate were placed in a brown tea bottle, and stirred for 1 minute using a pen mixer. The hole injection layer coating liquid 1 was obtained. The weight ratio of the hole injection-transporting compound to the particles in the composition was 43:57.

<Manufacture of <2mm square organic electric field light-emitting element>

An organic electroluminescent element was produced in accordance with the following method.

1. Preparation of the substrate

ITO was prepared to have an anode thickness of 70 nm on an alkali-free glass substrate (Nippon Electric Glass Co., Ltd. glass substrate "OA-10G", thickness: 0.7 mm), and ITO was carried out so that the light-emitting region became 2 mm squares. The patterning processor (hereinafter referred to as "2 mm square element ITO substrate").

2. Formation of the hole injection layer

In the atmosphere, on the above ITO substrate, the hole injection layer coating liquid 1 is used. Spin coating was applied at 2000 rpm for 30 seconds, and then initially hardened by heating in a clean oven at 230 ° C for 10 minutes. The film thickness at this time was 99 nm. Further, the hole injection layer coating liquid 1 was spin-coated at 2,500 rpm for 30 seconds on the preliminary hard coat film, and was first hardened by heating at 230 ° C for 10 minutes. After confirming that the film thickness reached the target value (about 150 nm), it was hardened by heating at 230 ° C for 1 hour. Thereby, a hole injection layer having a film thickness of 149 nm was formed.

3. Formation of the hole transport layer

On the above hole injection layer, the hole transport layer is a compound shown below: PPD(N,N'-diphenyl-N,N'-bis(9-phenanthryl)-1,1'-biphenyl The group 4,4'-diamine) was formed into a film thickness of 45 nm by a vacuum deposition method.

In addition, from the time of vapor deposition of the hole transport layer to the end of the following <sealing>, the treatment in a nitrogen atmosphere or a vacuum environment is adopted to avoid contact with oxygen or moisture.

4. Light-emitting layer

On the above-mentioned hole transport layer, the light-emitting layer was formed into a film thickness of 60 nm by vacuum vapor deposition of tris(8-hydroxyquinoline)aluminum (Alq ₃ ).

5. Formation of electron injection layer and cathode

On the electron transport layer, lithium fluoride (LiF) was deposited by vapor deposition to form an electron injecting layer, and then aluminum was used so as to have a film thickness of 80 nm. The vacuum vapor deposition method performs vapor deposition to form a cathode.

6. Seal

Next, in the nitrogen hand working box, a sheet-shaped dehydrated material is attached to the center of the concave portion of the countersunk glass (= glass which is processed into a concave shape), and the photocurable resin is applied to the outer peripheral portion. The beak glass is bonded to the glass substrate so as to cover the laminated body from the light-removed film to the cathode, and the resin is cured by being irradiated with ultraviolet light only to the region where the photocurable resin is applied. An organic electric field light-emitting element is obtained.

A schematic diagram of an organic electroluminescent device produced by the above method is shown in FIG.

2) Production of comparative organic electric field light-emitting elements (B1)

In the step of forming the hole injection layer, the transporting composition 1 is injected into the hole containing no particles, and the hole injection layer is formed so that the film thickness becomes a target value (about 150 nm). Except for this, an organic electroluminescent device (B1) was obtained in the same manner as in the organic electroluminescent device (A1) of the present invention.

2. Evaluation of light extraction effect

Using a total beam measuring system (a spectrometer: Solid-Lambda CCD, integrating sphere: SLMS-1011 manufactured by Labsphere) manufactured by Spectra Co-op Co., Ltd., it was measured that a direct current of 6.0 mA was applied to the produced organic electroluminescent element to emit light. The total beam amount [lumen (lm)].

The total beam amount of the organic electroluminescence device (A1) of the present invention is divided by the quotient of the total beam amount of the comparative organic electroluminescence device (B1) using the hole injection layer not containing particles, and is referred to as "light extraction magnification". Calculate. When the light extraction magnification exceeds 1.00, it is confirmed that there is a light extraction effect.

The light extraction magnification of the organic electroluminescent device of the present invention is 1.36, and it is determined that the light extraction efficiency is effective. fruit.

<Examples 2 to 3>

The target values of the film thicknesses of the hole injection layers were set to about 480 nm and about 600 nm, respectively, and the organic electroluminescent elements (A2) and (A3) and the comparative elements (B2) of the present invention were produced according to the method described in Example 1. (B3). As described in Table 14, even when the hole injection layer is the film thickness, the organic electroluminescent elements (A2) and (A3) of the present invention can still have a light extraction effect.

<Example 4> <Modulation of hole injection layer coating liquid 2 to 8>

The particle dispersion liquid described in the following Table 15 was mixed with the hole injection-transporting composition 1 to prepare hole injection layer coating liquids 2 to 8. The solid content of the sample dispersion No. 147, the trial production No. 236, the trial production No. 280, the trial production No. 281, and the trial production No. 237 of the particle dispersion were particles: dispersant = 10:1, PL-1- of the particle dispersion The solid content of TOL and MS-300K is only particles.

Hole injection layer coating liquid 2 to hole injection layer coating liquid 6 is based on a hole injection ratio of the transporting compound to the particle solids ratio of 53:47, and the hole injection layer coating liquid 7, hole injection The layer coating liquid 8 is prepared by mixing a hole into the transporting composition 1 and the particle dispersion so that the weight ratio of the transporting compound to the solid content of the particles is 50:50, and the hole injection layer is prepared. Coating solution 2~8.

Further, the organic electroluminescent device (A4-1 to A4-7) and the comparative device (B4) described in Table 16 were produced in the same manner as in Example 1 using the hole injection layer coating liquid. . The organic electroluminescence device (A4-1 to A4-7) of the present invention can find the light extraction effect regardless of the case.

<Example 5> <Preparation of Organic Electric Field Light-Emitting Element (A5) of the Present Invention>

An organic electroluminescent element was produced in accordance with the following method.

1. Fabrication of a substrate with an open bank

On the alkali-free glass substrate (Nippon Electric Glass Co., Ltd. glass substrate "OA-10G", thickness: 0.7 mm), ITO having an anode thickness of 70 nm was formed.

SPCM-144 (10.0g) manufactured by Showa Denko, NK Oligo U-6LPA (6.1g) manufactured by Shin-Nakamura Chemical Co., Ltd., IMGACURE 907 (0.8g) manufactured by Ciba, and propylene glycol monomethyl ether acetate (22.1) g) The mixture was mixed to prepare a negative photosensitive resin solution, and a negative photosensitive resin solution was spin-coated on the anode, and passed through a light-shielding mask having an opening area of 6 mm × 6 mm, and exposed by ultraviolet irradiation. After being developed by using an aqueous solution of tetramethylammonium hydroxide, it is allowed to stand in a hot air oven at 260 ° C for 1 hour. The bank was calcined to form an open bank having a wall surface height of 1.4 μm and an opening area of 6 mm × 6 mm.

<Modulation of the hole injection transporting composition 2>

A hole having a repeating unit shown below is injected into a transporting compound (HIL-2) and 4-isopropyl-4-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate at a weight ratio of 100 2: The mixture was mixed, and ethyl benzoate was added so that the concentration of the mixture became 6.0% by weight, and the mixture was heated and dissolved to prepare a hole for injecting the transportable composition 2.

<Modulation of the hole injection layer coating liquid 9>

The particle dispersion liquid 1 and the hole were injected into the transporting composition 2, and the weight ratio of the solid content of the transporting compound to the particles was 50:50, and the hole injection layer coating liquid 9 was prepared.

On the anode surrounded by the open bank, the hole injection layer coating liquid 9 is spin-coated to form a hole injection layer. Hereinafter, a 6 mm square organic electroluminescent element (A5) was produced in the same manner as in Example 1.

An outline of an organic electroluminescent device produced in accordance with the above method is shown in FIG.

<Preparation of Organic Electric Field Light-Emitting Element (A6) and Comparative Element (B5) and (B6) of the Present Invention>

Except for the hole injection layer coating liquid 1 described in Table 15, except for the hole injection layer coating liquid 1 described in Table 15, the organic electroluminescent element was produced in the same order as the production of the organic electroluminescent element (A5). A6), in addition to the formation of the hole injection layer, the above-described holes are used to inject the transportable compositions 2 and 1, and the rest are produced in the same order as the production of the organic electroluminescent element (A5) (B5) And (B6).

In either case, the light extraction effect can be found in the elements of the present invention. Further, from the comparison between Example 1 and Example 6, it was confirmed that the present invention can be found when the light-emitting area is large. The light extraction effect is larger (size dependent effect).

<Comparative Examples 1, 2> <Modulation of the hole injection layer coating liquid 10 to 13>

PEDOT/PSS dispersion made by Heraeus Co., Ltd. "Clevios P VP AL4083 (PEDOT/PSS = 1/6 weight ratio, solid content concentration: 1.5%), and colloidal cerium oxide sol "Snowtex OS" manufactured by Nissan Chemical Industries Co., Ltd., according to PEDOT /PSS and the solid weight ratio of the particles were mixed at a ratio of 50:50 to prepare a hole injection layer coating liquid 10. Further, the hole injection layer coating liquid 11 was prepared by combining "Snowtex O40".

Furthermore, according to the combination of the PEDOT/PSS dispersion "Clevios P VP CH8000 (PEDOT/PSS = 1/20 weight ratio, solid content concentration 3%) and "Snowtex OS" or "Snowtex O40" manufactured by Heraeus Co., Ltd., The hole injection layer coating liquids 12 and 13 (all mixed according to PEDOT/PSS and a solid weight ratio of particles to 50:50).

The hole injection layer coating liquids 10 to 13, and "CLEVIOS P VP AL4083" and "Clevios P VP CH8000" were respectively spin-coated on a 2 mm square element ITO substrate, and were applied to a 135 ° C hot plate. Heated and dried in minutes to form a hole Inject the layer. Then, organic electroluminescent elements (C1-1 to C2-2) and comparative elements (D1, D2) outside the invention were produced in the order described in the first embodiment. As shown in Table 20.

The components other than the invention had a light extraction magnification of 1.00 or less, and no light extraction effect was observed.

<Comparative Example 3> 1) Production of organic electric field light-emitting element (E1) <Modulation of the hole injection layer coating liquid 14>

The particle dispersion liquid 1-2 was prepared in the same manner as in Example 1. The average particle diameter of the dispersion at this time was 118 nm. The particle dispersion liquid 1-2 (25 parts by weight) and the hole injection-transporting composition 1 (100 parts by weight) prepared in the same manner as in Example 1 were mixed to prepare a hole injection layer coating liquid 14. The weight ratio of the hole injection-transporting compound to the particles in the composition was 54:46.

On the same substrate as the user of Example 1, the hole injection layer coating liquid 14 was spin-coated at 1000 rpm for 30 seconds, and immediately placed in a vacuum dryer for 1 minute under reduced pressure drying. Then, using a heating plate at 230 ° C for 10 minutes to form a hardening Coating film. The film thickness at this time was 310 nm. In the same manner as in the hard coat film, the hard coat film was laminated to form a film four times. Further, on the cured coating film, the hole injection layer coating liquid 14 was spin-coated at 1500 rpm for 30 seconds, and immediately placed in a vacuum dryer for 1 minute under reduced pressure drying, followed by heating at 230 ° C. The plate was heated for 10 minutes to form a hard coating film. As described above, a hole injection layer having a film thickness of 1570 nm was formed on the substrate.

On the hole injection layer, a hole transport layer, a light-emitting layer, an electron injection layer, and a cathode were formed in the same manner as in Example 1, and an organic electroluminescence element (E1) was obtained by sealing.

2) Production of organic electric field light-emitting element (F1)

In the step of forming the hole injection layer, the transportable composition 1 is injected using a cavity containing no particles, and the organic electroluminescent device (F1) is obtained in the same manner as the organic electroluminescent device (E1). The hole injection layer film thickness at this time was 1500 nm.

3) Evaluation of light extraction effect

The evaluation was carried out in accordance with the method described in Example 1. As a result, as shown in Table 21, when the hole injection layer was the film thickness, almost no light extraction effect was observed.

<Example 6> 1) Production of organic electric field light-emitting element (G1) of the present invention <Modulation of the hole injection transporting composition 3>

A hole having a repeating unit shown below is injected into a transporting compound (HIL-3), and 4-isopropyl-4-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, by weight ratio 100. 2: The mixture was mixed, and ethyl benzoate was added so as to have a mixture concentration of 5.0% by weight, and the mixture was heated to dissolve, and the hole was injected into the transportable composition 3.

<Modulation of the hole injection layer coating liquid 15>

The particle dispersion liquid 1-2 and the hole are injected into the transporting composition 3, and the weight ratio of the solid content of the transporting compound to the particles is 54:46, and the hole injection layer coating liquid is prepared. 15.

On the same substrate as the user of Example 1, the hole injection layer coating liquid 15 was spin-coated at 1000 rpm for 30 seconds, and immediately placed in a vacuum dryer for 1 minute under reduced pressure drying. Next, the plate was heated by a hot plate at 230 ° C for 10 minutes to form a cured coating film. The film thickness at this time was 330 nm. Further, on the cured coating film, the hole injection layer coating liquid 15 was spin-coated at 1500 rpm for 30 seconds, and immediately placed in a vacuum dryer for 1 minute under reduced pressure drying, followed by heating at 230 ° C. Heating was performed for 10 minutes to form a hard coating film. As described above, a hole injection layer having a film thickness of 530 nm was formed on the substrate.

On the hole injection layer, a hole transport layer, a light-emitting layer, an electron injection layer, and a cathode were formed in the same manner as in Example 1, and the organic electroluminescence element (G1) was obtained by sealing.

2) Production of organic electroluminescent element (H1) for comparison

In the step of forming the hole injection layer, the transportable composition 3 is injected into the cavity containing no particles, and the organic electroluminescent device (H1) is obtained in the same manner as the organic electroluminescent device (G1). The hole injection layer film thickness at this time was 460 nm.

3) Evaluation of light extraction effect

The evaluation was carried out in accordance with the method described in Example 1. As a result, as shown in Table 22, the light extraction effect was also observed when the hole injection-transporting compound was (HIL-3).

The present invention has been described with reference to the specific embodiments thereof, and various modifications and changes can be made without departing from the spirit and scope of the invention. The present application is based on the Japanese Patent Application (Japanese Patent Application No. 2012-248541) filed on Nov. 12, 2012, which is incorporated herein by reference.

1‧‧‧ hole injection layer

2‧‧‧ hole transport layer

3‧‧‧Lighting layer

4‧‧‧Electronic injection layer

5‧‧‧ cathode

6‧‧‧Anode

7‧‧‧ glass substrate

9‧‧‧Flake dehydrated material

10‧‧‧ cone glass

11‧‧‧Photocurable resin

Claims (8)

An organic electroluminescence device comprising: an anode and a cathode; and an organic electroluminescence device that selects at least one of a hole injection layer and a hole transport layer formed between the anode and the cathode; In at least one of the hole injection layer and the hole transport layer, particles are dispersed, and at least one of the hole injection layer and the hole transport layer is selected to have a film thickness of 100 nm or more and 1000 nm or less. . The organic electroluminescent device of claim 1, wherein at least one of the hole injection layer and the hole transport layer is selected to contain a hole in which the transporting material is high in aromatic tertiary amine. Molecular compound. The organic electroluminescence device of the first or second aspect of the invention, wherein the particles are at least one selected from the group consisting of metal oxides, composite oxides, and polymer materials. The organic electroluminescence device according to any one of claims 1 to 3, wherein the particles have an average particle diameter of 10 nm or more and 300 nm or less. The organic electroluminescence device according to any one of claims 1 to 4, wherein at least one of the hole injection layer and the hole transport layer is selected by a wet film formation method. The organic electroluminescence device according to any one of claims 1 to 5, further comprising a hole transport layer and a light-emitting layer. An organic EL display device comprising the organic electroluminescence device according to any one of claims 1 to 6. An organic EL illumination device comprising the organic electroluminescence device of any one of claims 1 to 6.