Composition for organic electroluminescent element, organic electroluminescent element, and organic electroluminescent display

Abstract

To provide a composition for an organic electroluminescent element that is for producing the organic electroluminescent element capable of being driven at low voltages and having a long drive life.SOLUTION: A composition for an organic electroluminescent element includes an organic polymer compound having repeating units represented by the following formula (1) and an organic solvent. The absorbance at an optical path length of 10 mm and a wavelength of 500 nm is 0.2 or higher, and the absorbance at an optical path length of 10 mm and a wavelength of 800 nm is 0.05 or higher.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composition for an organic electroluminescent device, and an organic electroluminescent device using this composition. This invention relates to a field-emitting element and an organic EL display equipped therewith. [Background technology]

[0002] In recent years, inorganic materials such as ZnS have been used as electroluminescence (EL) elements. Instead, development is underway on electroluminescent devices using organic materials (organic electroluminescent devices). In organic electroluminescent devices, high luminescence efficiency is one of the important factors, but luminescence Regarding the ratio, the hole transport layer contains aromatic amine compounds and 8-hydroxyquinoline This was significantly improved by using an organic electroluminescent device equipped with a light-emitting layer made of a titanium complex.

[0003] A major challenge to expanding the demand for organic electroluminescent devices is the decrease in driving voltage. For example, Display elements in portable devices require low-voltage operation from batteries, and also for applications other than portable use. Even in general applications, there is a demand for display elements with low power consumption, and a decrease in drive voltage is a significant factor. This directly leads to a reduction in power consumption. Furthermore, the gradual increase in drive voltage during continuous operation is also a factor. Maintaining stable display characteristics of the display element is a major challenge.

[0004] To solve these problems, a hole transport compound and an electron acceptor compound are reacted, It is disclosed that a cation radical species that acts as a carrier of charge transport is generated (Patent text) References 1-3, Non-Patent Document 1). Generally, arylamine polymers have hole transport properties, and organic It is suitably used as a hole transport material in field-luminescent devices. Arylamine polymer and electron receiver Reacting a capacitive compound to generate a cation radical species that serves as a carrier for charge transport Thereby, hole injection from the electrode is promoted, and the organic electroluminescent device can be operated at a lower voltage or have a longer lifespan .

[0005] In recent years, the energy difference between the ground state and the excited state of the light-emitting layer material used in organic electroluminescent devices has tended to increase. Along with this, light-emitting layer materials with a deep ionization potential have come to be used . As the ionization potential of the light-emitting layer material has become deeper, hole injection layers and hole transport layers used between the anode and the light-emitting layer also need to have materials with a deep ionization potential . By substituting an electron-withdrawing group containing a fluorine atom into an arylamine polymer, it is possible to deepen the ionization potential of the arylamine polymer . However, in the conventional technology, the generation of cation radical species that serve as carriers for charge transport on the arylamine polymer substituted with an electron-withdrawing group containing a fluorine atom is insufficient, and improvement has been demanded

[0006] . . .

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0008]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention aims to provide a composition for an organic electroluminescent device, an organic electroluminescent device, and an organic EL display including the same, which can be driven at a low voltage and have a long driving life. and have a long driving life.

Means for Solving the Problems

[0010] As a result of intensive studies, the inventors of the present invention have found that by dissolving an arylamine polymer having an electron-withdrawing group substituted with a specific fluorine atom and an electron-accepting compound in an organic solvent and reacting them, the absorbance at an optical path length of 10 mm and a wavelength of 500 nm is 0.2 or more, and further, the absorbance at an optical path length of 10 mm and a wavelength of 800 nm is 0.05 or more, and have found that the above problems can be solved, thus arriving at the present invention. [[ID=二十九]]

[0011] That is, the present invention provides a composition for an organic electroluminescent device including an arylamine polymer having an electron-withdrawing group substituted with a specific fluorine atom and an organic solvent, wherein the absorbance at an optical path length of 10 mm and a wavelength of 500 nm is 0.2 or more, and the absorbance at an optical path length of 10 mm and a wavelength of 800 nm is 0.05 or more. The present invention also provides an organic electroluminescent device including an organic layer formed using the composition, and an organic EL display including the device. exists in the display. [1] including an organic polymer compound having a repeating unit represented by the following formula (1) and an organic solvent ​In an organic electroluminescent element composition, the absorbance at an optical path length of 10 mm and a wavelength of 500 nm is The value is 0.2 or higher, and the absorbance at a path length of 10 mm and a wavelength of 800 nm is 0.05 or higher. A composition for an organic electroluminescent element characterized by certain features.

[0012] [ka]

[0013] (In formula (1), Ar 1 This is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, which may have substituents, or is substituted. A divalent aromatic heterocyclic group having 3 to 50 carbon atoms, which may have a group, or a substituent having A good aromatic hydrocarbon group or an aromatic heterocyclic group which may have substituents is directly or This represents a divalent group linked together via a linking group. G represents a phenylene group or naphthylene group containing substituent A of formula (1-1), A consists of F, CF3, and SF5. Ar 2 A is an aromatic hydrocarbon group having 6 to 60 carbon atoms, which may have substituents. , an aromatic heterocyclic group having 3 to 50 carbon atoms which may have substituents, or which have substituents A group selected from a good aromatic hydrocarbon group and an aromatic heterocyclic group which may have substituents. This represents a monovalent group that is linked directly or via a linking group. m is an integer from 1 to 4. n is an integer between 1 and 6.

[0014] [2] The organic solvent is less than or equal to an ether-based solvent, a ketone-based solvent, or a hydrocarbon-based solvent. The organic electroluminescent element composition according to [1], characterized by containing at least one of these elements. [3] The absorption at 500 nm and 800 nm is derived from cationic radical species. A composition for an organic electroluminescent element according to any one of [1] to [2], characterized by the above. [4] Organic electroluminescent element comprising a substrate and an anode, an organic layer, and a cathode provided on the substrate. A child wherein the organic layer is an organic electroluminescent composition according to any one of [1] to [3]. An organic electroluminescent element characterized by comprising an organic layer formed using [a specific method / tool]. [5] The organic layer is characterized in that it includes a light-emitting layer, and the light-emitting layer is formed by a wet film deposition method. The organic electroluminescent element described in [4]. [6] The light-emitting layer is characterized by containing a light-emitting low molecular weight compound, [4] or [5] Organic electroluminescent element as described in [ ]. The features include an organic electroluminescent element as described in any of [7], [4], to [6]. Organic EL display. [Effects of the Invention]

[0015] The organic electroluminescent element obtained using the organic electroluminescent element composition of the present invention is low voltage It is drivable, can reduce power consumption, and has a long operating life. According to the present invention, an organic electroluminescent element has stable display characteristics when driven at low voltage. We can provide EL displays. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic cross-sectional view showing an example of the structure of the organic electroluminescent element of the present invention. [Modes for carrying out the invention]

[0017] The present invention provides a composition for organic electroluminescent devices, an organic electroluminescent device, and an organic EL display. The details will be explained below, but the description of the constituent elements described below is an example of an embodiment of the present invention (substitute (The table is an example) and the present invention is not limited to these contents unless it exceeds the gist thereof.

[0018] <Composition for Organic Electroluminescent Light-Emitting Devices> The organic electroluminescent light-emitting composition of the present invention has repeating units represented by the following formula (1) In an organic electroluminescent device composition comprising an organic polymer compound and an organic solvent, by the following method The absorbance at the measured wavelength of 500 nm is 0.2 or higher, and at a wavelength of 800 nm... It is characterized by having an absorbance of 0.2 or higher.

[0019] [ka]

[0020] (In formula (1), Ar 1 This is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, which may have substituents, or is substituted. A divalent aromatic heterocyclic group having 3 to 50 carbon atoms, which may have a group, or a substituent having A good aromatic hydrocarbon group or an aromatic heterocyclic group which may have substituents is directly or This represents a divalent group linked together via a linking group. G represents a phenylene group or naphthylene group containing substituent A of formula (1-1), A consists of F, CF3, and SF5. Ar 2 A is an aromatic hydrocarbon group having 6 to 60 carbon atoms, which may have substituents. , an aromatic heterocyclic group having 3 to 50 carbon atoms which may have substituents, or which have substituents A group selected from a good aromatic hydrocarbon group and an aromatic heterocyclic group which may have substituents. This represents a monovalent group that is linked directly or via a linking group. m is an integer from 1 to 4. n is an integer between 1 and 6.

[0021] [Method for measuring absorbance] The absorbance of the organic electroluminescent element composition of the present invention at a wavelength of 500 nm, and at a wavelength of 80 The absorbance at 0 nm was measured using a Hitachi U-3900H spectrophotometer as follows: It is measured under certain conditions. Measurement conditions: Measurement mode: Wavelength scan Data mode: Abs Starting wavelength: 1000nm Ending wavelength: 200nm Scan speed: 300nm / min Sampling interval: 0.50 nm Slit: 5nm Light source switching wavelength: 340nm Cell length: 10mm

[0022] For the reference measurements, the organic solvent contained in each organic electroluminescent element composition was used. Furthermore, the measuring instrument used for the specification of this invention is acceptable as long as it is capable of the same measurement as described above. While not limited to the above-mentioned equipment, other measuring instruments may also be used. It is preferable to use it. The organic electroluminescent light-emitting composition of the present invention has an optical path length of 10 mm, as measured by the above measurement method. The absorbance at a wavelength of 500 nm (hereinafter sometimes referred to as "absorbance (500)") is 0 The absorbance is 0.2 or greater, and the absorbance at a path length of 10 mm and a wavelength of 800 nm (hereinafter referred to as "absorbance (8") It is sometimes referred to as "00)". ) is 0.05 or higher.

[0023] If the absorbance is greater than or equal to the above value, a charge transport film with high charge transport capacity can be obtained, and the resulting device This is preferable because the driving voltage decreases. This is because the absorption at wavelengths of 500 nm and 800 nm is It originates from a cationic radical species, and if the absorbance at this wavelength is high, a sufficient amount of cationic radical is present. This is because calcium species are generated, and hole transport is enhanced. From this perspective, the absorbance (500) of the organic electroluminescent element composition of the present invention is 0.2 It is preferable that it be above 0.3, and more preferably 0.3 or above. The absorbance (800) of the light-emitting element composition is preferably 0.05 or higher, and more preferably... The value is 0.08 or higher.

[0024] There are no particular upper limits on absorbance (500) and absorbance (800), but usually absorbance (5 The value of (00) is 10.0 or less, and the absorbance of (800) is 5.0 or less. The absorbance (500) and absorbance (800) of the organic electroluminescent light-emitting composition of the present invention are as follows: In order to exceed the limit, the organic electroluminescent element composition of the present invention contains a specific organic according to the present invention. A polymer compound is used, and a suitable organic solvent and electron-accepting compound are combined with it. One method involves using a component composition that is conducive to the generation of cation radicals.

[0025] <Composition for hole injection and transport layer formation> When the composition for the organic electroluminescent element of the present invention is a composition for hole injection and transport layer formation, Examples of components are shown below, but the present invention is not limited to these. Furthermore, if the organic electroluminescent light-emitting element composition of the present invention is a hole injection / transport layer forming composition: These are hole injection and transport materials that are easily oxidized by one electron, and electron-accepting compounds that are easily oxidized by one electron. Furthermore, the hole injection / transport material and electron-accepting compounds are dissolved in the solvent, and radical species are stabilized in the solvent. It is preferable that the composition contains an organic solvent that can be harmonized.

[0026] <Hole injection and transport materials> The present invention is used as a composition for forming an organic electroluminescent element, and is used as a hole injection / transport layer composition. In this case, the contained organic compound is preferably a hole injection / transport material. The material used for hole injection and transport should be appropriately selected from the materials listed below to form the configuration of the present invention. It is possible.

[0027] (Molecular weight of hole injection / transport material) The hole injection and transport material according to the present invention may be a low molecular weight compound or a high molecular weight compound. However, in terms of heat resistance, charge transport properties, and film-forming properties, it is preferable that it be a polymer compound. stomach. In this invention, the low molecular weight compound is not one that has a distribution of molecular weights, but rather one with a single molecular weight. This refers to a compound having [a certain characteristic]. Furthermore, the polymer compound in this invention refers to a compound having a distribution in molecular weight. This refers to a compound, for example, one that has repeating units in its structure.

[0028] When the hole injection / transport material is a low molecular weight compound, its molecular weight is usually 300 or higher, preferably. The range is 500 or more, and usually 5000 or less, preferably 2500 or less. If the molecular weight of the input / transport material is too small, the charge transport performance may decrease, and if it is too large, it may dissolve. The ability to solve the problem may decrease. On the other hand, when the hole injection / transport material is a polymer compound, the weight-average molecular weight is usually 500. Preferably 2000 or more, more preferably 4000 or more, and usually 2,000. A range of 000 or less, preferably 500,000 or less, more preferably 200,000 or less. Therefore, if the weight-average molecular weight of the hole injection / transport material falls below this lower limit, hole injection / transport The film-forming properties of the material may be reduced, and the glass material used for hole injection and transport may also be affected. The transition temperature, melting point, and vaporization temperature will decrease, which may significantly impair the heat resistance. When the weight-average molecular weight of the pore-injection / transport material exceeds this upper limit, the molecular weight of impurities increases. This may make it difficult to purify hole injection and transport materials.

[0029] This weight-average molecular weight was determined by SEC (size exclusion chromatography) measurement. In SEC measurements, components with higher molecular weight have shorter elution times, and components with lower molecular weight have shorter elution times. This will be lengthy, but here is a calibration curve calculated from the elution time of polystyrene (standard sample) with a known molecular weight. By using this method and converting the sample elution time to molecular weight, the weight-average molecular weight is calculated. The same calculation is performed for the number-average molecular weight. The weight of hole-transporting polymer compounds, etc., described later... The same applies to quantity-average molecular weight and number-average molecular weight.

[0030] (Structure of hole injection and transport materials) <<Definition>> The structures of the electron-accepting compound and charge-transporting polymer compound (polymer) according to the present invention are described below. For detailed explanation, unless otherwise specified, the common substructures are as follows: Let's assume that. In the present invention, "may have substituents" means that it may have one or more substituents. This means...

[0031] <Aromatic hydrocarbon group> Aromatic hydrocarbon groups are defined as groups of compounds whose bonding state within the structure is determined later. This refers to a monovalent, divalent, or trivalent or more aromatic hydrocarbon ring structure. In the structure of an aromatic hydrocarbon ring, the number of carbon atoms is usually not restricted, but is preferable. The carbon number is 6 or more and 60 or less, and more preferably 48 or less as the upper limit of the carbon number. More preferably, the number of carbon atoms is 30 or less. Specifically, as aromatic hydrocarbon groups, Naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene Ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, flu orantene rings, fluorene rings, and other 6-membered monocyclic or 2-5 fused ring groups, or these Examples include structures in which multiple groups selected from are linked together. Multiple aromatic hydrocarbon rings are linked together. When connecting, a structure of 2 to 10 units is usually used, and a structure of 2 to 5 units is also used. This is preferable. When multiple aromatic hydrocarbon rings are linked, the same structure may be linked. Different structures may be connected.

[0032] Preferably, the aromatic hydrocarbon ring structure is a benzene ring, a biphenyl ring, i.e., benzene. A structure in which two rings are linked, a terphenyl ring, or a structure in which three benzene rings are linked, a quarter These are structures consisting of four linked phenylene rings (benzene rings), naphthalene rings, and fluorene rings. .

[0033] <Aromatic heterocyclic group> Aromatic heterocyclic groups are defined according to their bonding state within the structure of the compounds described later. This refers to a monovalent, divalent, or trivalent or more aromatic heterocyclic structure. In the structure of an aromatic heterocycle, the number of carbon atoms is not usually limited, but preferably The carbon number is 3 or more and 60 or less, and more preferably 48 or less as the upper limit of the carbon number. More preferably, the carbon number is 30 or less. Specifically, as aromatic heterocyclic groups, furan Ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, Imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazo Pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienopyrrole ring, thienopyrrole fen Ring, phlopyrrole ring, flofuran ring, thienofuran ring, benzoisoxazole ring, ben Zoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, Pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, synnoline ring, quinoxali cin ring, phenanthidine ring, benzimidazole ring, perimidine ring, quinazoline ring, quina A divalent group of a 5-6 membered mono-ring or 2-4 fused ring, such as a zolinone ring or azulene ring. Examples include groups formed by linking multiple such groups. When multiple aromatic heterocycles are linked together, the same structure is formed. They may be linked, and different structures may be linked. When multiple aromatic heterocycles are linked, Typically, a structure consisting of 2 to 10 connected units is common, and a structure consisting of 2 to 5 connected units is preferred. . Preferred aromatic heterocyclic structures include a thiophene ring, a benzothiophene ring, and a pyrimidine. These are rings, triazine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings.

[0034] <Bridging group> A crosslinking group is a group located near the crosslinking group due to irradiation with heat and / or active energy rays. This refers to a group that reacts with other crosslinking groups to form new chemical bonds. The group may be the same as the bridging group or a different group. The crosslinking group is not limited to, but may include groups containing alkenyl groups, groups containing conjugated diene structures, Groups containing an alkynyl group, groups containing an oxirane structure, groups containing an oxetane structure, aziridine Groups containing structures, azide groups, groups containing maleic anhydride structures, alkenyls bonded to aromatic rings Examples include groups containing a group, and cyclobutene rings fused to aromatic rings. Preferred crosslinking groups include Examples include those represented by any of the following formulas (X1) to (X18) in the following crosslinking group T. It is preferable.

[0035] <Bridging group T>

[0036] [ka]

[0037] [In formulas (X1) to (X18), Q represents a direct bond or linking group. The asterisk (*) indicates the joining position. R in formula (X4), formula (X5), formula (X6) and formula (formula 10) 110 is a hydrogen atom or This represents an alkyl group that may have an alternative group. In formulas (X1) to (X4), the benzene ring and the naphthalene ring may have substituents. Furthermore, substituents may bond to each other to form a ring. In formulas (X1) to (X3), the cyclobutene ring may have substituents.

[0038] (Q) If Q in equations (X1) to (X18) is a linking group, the linking group is not particularly limited, however Preferably, an alkylene group, a divalent oxygen atom, or a divalent aromatic carbon which may have substituents. It is a hydrogenated group.

[0039] The alkylene group typically has 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably A mashiku is an alkylene group having 1 to 6 carbon atoms. The divalent aromatic hydrocarbon group typically has 6 or more carbon atoms, and usually 36 or fewer carbon atoms. Preferably 30 or less, more preferably 24 or less, and having an aromatic hydrocarbon ring structure. A benzene ring is preferred, and the substituents that may be present are selected from the substituent group Z described below. It is possible.

[0040] R 110The alkyl group represented by is linear, branched, or cyclic, and has one or more carbon atoms. Preferably, it is 24 or less, more preferably 12 or less, and even more preferably 8 or less. The benzene ring and naphthalene ring in formulas (X1) to (X4), and formulas (X4) and (X 5) R in equations (X6) and (X10) 110 Preferred substituents that may be present These are alkyl groups, aromatic hydrocarbon groups, alkyloxy groups, and aralkyl groups.

[0041] The alkyl group as a substituent has a linear, branched, or cyclic structure, and preferably has 24 carbon atoms. The following is more preferably 12 or less, even more preferably 8 or less, and preferably 1 or more. ru. The number of carbon atoms in the aromatic hydrocarbon group as a substituent is preferably 24 or less, more preferably 1 The aromatic hydrocarbon is 8 or less, more preferably 12 or less, and preferably 6 or more. The group may further have the alkyl group as a substituent.

[0042] The number of carbon atoms in the alkyloxy group as a substituent is preferably 24 or less, more preferably k is 12 or less, more preferably 8 or less, and preferably 1 or more. The number of carbon atoms in the aralkyl group as a substituent is preferably 30 or less, more preferably The aralkyl group is 24 or less, more preferably 14 or less, and more preferably 7 or more. The alkylene group contained is preferably in a linear or branched structure. The aryl group contained in the aralkyl group The group may further have the alkyl group as a substituent.

[0043] Preferably substituents that the cyclobutene ring of formulas (X1) to (X3) may have , alkyl group. The alkyl group as a substituent has a linear, branched, or cyclic structure, carbon The prime number is preferably 24 or less, more preferably 12 or less, and even more preferably 8 or less. Preferably, it is 1 or more. The bridging group is a bridging group represented by any of the formulas (X1) to (X3), which can be bridged by heat alone. This is preferable because it facilitates bridge reactions, has low polarity, and has minimal impact on charge transport.

[0044] The crosslinking group represented by formula (X1) opens its cyclobutene ring upon heat, as shown in the following formula. The ring-shaped groups bond together, forming a cross-linked structure. In the following, equations (X1) to (X The linking element Q in 3) etc. is omitted from the description.

[0045] [ka]

[0046] The bridging group represented by formula (X2) opens its cyclobutene ring upon heat, as shown in the following formula. The ring-shaped groups bond together, forming a cross-linked structure.

[0047] [ka]

[0048] The bridging group represented by formula (X3) opens its cyclobutene ring upon heat, as shown in the following formula. The ring-shaped groups bond together, forming a cross-linked structure.

[0049] [ka]

[0050] A bridging group represented by any of formulas (X1) to (X3) undergoes a cyclobutene ring opening upon heat. When a ring-opened group is present in the vicinity of a double bond, it reacts with the double bond to form a bridging structure. To form. Below is formula (X4), in which the bridging group represented by formula (X1) has a ring-opened group and a double bond site. This shows an example of how the crosslinking group represented by forms a crosslinked structure.

[0051] [ka]

[0052] It contains a double bond that can react with a crosslinking group represented by any of formulas (X1) to (X3). In addition to the bridging group represented by formula (X4), there are also formulas (X5), (X6), and (X12) ), expressed as any of the following: (X15), (X16), (X17), and (X18) Crosslinking groups are examples. These double bond-containing groups are crosslinking groups in electron-accepting compounds. When used as such, it forms a hole injection layer and / or hole transport layer such as a hole transport compound. The other components may contain a crosslinking group represented by any of formulas (X1) to (X3). This increases the likelihood of forming a cross-linked structure, which is preferable.

[0053] The crosslinking group can be any of the radical polymerizable compounds (X4), (X5), or (X6). The bridging group represented by is preferred because it has low polarity and does not easily hinder charge transport. As a crosslinking group, the crosslinking group represented by formula (X7) is preferred in that it enhances electron-accepting ability. Furthermore, when the crosslinking group represented by formula (X7) is used, the following crosslinking reaction proceeds.

[0054] [ka]

[0055] A crosslinking group represented by either formula (X8) or (X9) is preferred due to its high reactivity. Using the crosslinking group represented by formula (X8) and the crosslinking group represented by formula (X9), the following A cross-linking reaction like this proceeds.

[0056] [ka]

[0057] As crosslinking groups, cationic polymerizable compounds of formulas (X10), (X11), and (X12) The crosslinking group represented by either of the above is preferred because of its high reactivity.

[0058] <Substituent> In the following description of the structures of polymer compounds and low molecular weight compounds in the present invention, there is no particular limitation. If not present, the substituent is any group, but is preferably selected from the substituent group Z below. It is a base. Furthermore, in describing the structures of polymer compounds and low molecular weight compounds in the present invention, The substituents that may be present are selected from substituent group Z, or the substituents that may be present are from substituent group Z. If it is stated that it is preferable to select from the following substituents, then the preferred substituents are also from the substituent group Z below. It is as written.

[0059] <Substituent group Z> The substituent group Z consists of alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, and aryl groups. Xy group, heteroaryloxy group, alkoxycarbonyl group, dialkylamino group, dia Rieol amino group, arylalkylamino group, acyl group, halogen atom, haloalkyl group alkylthio group, arylthio group, silyl group, siloxy group, cyano group, aromatic hydrocarbon This group consists of a group and an aromatic heterocyclic group. These substituents can be linear, branched, or cyclic. This structure may be included.

[0060] More specifically, the substituent group Z includes the following structures. The carbon number is 1 or more, preferably 4 or more, 24 or less, preferably 12 or less, Linear, branched, or cyclic alkyl groups, preferably 8 or less, and more preferably 6 or less. Groups. Specific examples include methyl group, ethyl group, n-propyl group, i-propyl group, and n-butyl group. group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group Examples include xyl groups and dodecyl groups.

[0061] The number of carbon atoms is usually 2 or more, usually 24 or less, preferably 12 or less, linear, branched, Or a cyclic alkenyl group; a specific example would be a vinyl group. A linear or branched chain having typically 2 or more carbon atoms, typically 24 or less, and preferably 12 or less. Alkynyl groups; specific examples include ethynyl groups. An alkoxy group having 1 or more carbon atoms, and 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms. Specific examples and Examples include methoxy groups and ethoxy groups.

[0062] The carbon number is 4 or more, preferably 5 or more, 36 or less, and preferably 24 or less. an aryloxy group or a heteroaryloxy group. A specific example is the phenoxy group. Examples include naphthoxy groups and pyridyloxy groups. An alkoxycarbonyl group having 2 or more carbon atoms, 24 or less, preferably 12 or less. Specific examples include methoxycarbonyl groups and ethoxycarbonyl groups.

[0063] A dialkylamino group having 2 or more carbon atoms, and 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms. Examples include dimethylamino groups and diethylamino groups. Dia has 10 or more carbon atoms, preferably 12 or more, and 36 or fewer carbon atoms, preferably 24 or fewer. Lilleamino group. Specific examples include diphenylamino group, ditolylamino group, and N-carbamino group. Examples include the zolyl group.

[0064] Arylalkylamino having 7 or more carbon atoms, and 36 or less, preferably 24 or less. A group. A specific example is the phenylmethylamino group. An acyl group having 2 or more carbon atoms, and 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms. Examples include acetyl groups and benzoyl groups. Halogen atoms such as fluorine atoms and chlorine atoms. Preferably, fluorine atoms.

[0065] A haloalkyl group having 1 or more carbon atoms, and 12 or fewer carbon atoms, preferably 6 or fewer carbon atoms. Specific examples include Examples include trifluoromethyl groups. An alkylthio group having 1 or more carbon atoms, usually 24 or fewer, preferably 12 or fewer. Examples include methylthio groups and ethylthio groups. Ants with 4 or more carbon atoms, preferably 5 or more, and 36 or less, preferably 24 or less. Phenylthio groups. Specifically, examples include phenylthio groups, naphthylthio groups, and pyridylthio groups. It can be done.

[0066] The number of carbon atoms is usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less. A certain silyl group. Specific examples include the trimethylsilyl group and the triphenylsilyl group. It can be done. The number of carbon atoms is 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less. Siloxy group. Specific examples include trimethylsiloxy group and triphenylsiloxy group. It is possible.

[0067] Cyano group. An aromatic hydrocarbon group having 6 or more carbon atoms, and 36 or fewer carbon atoms, preferably 24 or fewer carbon atoms. Examples include phenyl groups, naphthyl groups, and groups formed by linking multiple phenyl groups. . A fragrance having 3 or more carbon atoms, preferably 4 or more, and 36 or less, preferably 24 or less. A heterocyclic group. Specific examples include the thienyl group and the pyridyl group.

[0068] The substituents may include linear, branched, or cyclic structures. If the above substituents are adjacent, they may bond to each other to form a ring. The sizes of the rings are 4-membered, 5-membered, and 6-membered rings, and specific examples include the cyclobutane ring. These are cyclopentane rings and cyclohexane rings. Among the substituent group Z described above, alkyl groups, alkoxy groups, and aromatic hydrocarbons are preferred. The group is an aromatic heterocyclic group.

[0069] Furthermore, each substituent in the substituent group Z may have further substituents. Examples include those identical to the substituent group Z described above, or a crosslinking group. Preferably, further substituents are used. It does not have, or it has an alkyl group with 8 or fewer carbon atoms, an alkoxy group with 8 or fewer carbon atoms, or phenyl A group, more preferably an alkyl group having 6 or fewer carbon atoms, an alkoxy group having 6 or fewer carbon atoms, or a fe It is a nyl group. From the viewpoint of charge transport, it is more preferable that it does not have further substituents. . If each substituent in the above substituent group Z may further have a substituent that is a bridging group, then the bridging group is the A crosslinking group selected from the group T is preferred. A substitution further having a crosslinking group is preferred. The group is an alkyl group or an aromatic hydrocarbon group.

[0070] [Charge-transporting polymer compound] The composition of the present invention preferably contains a hole-transporting polymer compound as the charge-transporting polymer compound. The hole-transporting polymer compound is usually used to form a hole injection layer or a hole transport layer and is included in the composition for forming a charge transport film described below. In this case, the composition of the present invention can be used to form a hole injection layer or a hole transport layer.

[0071] [Organic polymer compound having a repeating unit represented by formula (1)] In this case, the composition of the present invention contains, as the hole-transporting polymer compound, an organic polymer compound represented by the following formula (1) (hereinafter sometimes referred to as "organic polymer compound (1)"), and preferably, this organic polymer compound (1) has a crosslinking group.

[0072] [Chemical formula]

[0073] (In formula (1), Ar 1 represents a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, a divalent aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups or aromatic heterocyclic groups which may have a substituent are directly or indirectly linked via a linking group, G represents a phenylene group or a naphthylene group containing the substituent A of formula (1-1), A is F, CF3, or SF5. Ar 2 represents A, or an aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, or ​​​​​​​​A group selected from a good aromatic hydrocarbon group and an aromatic heterocyclic group which may have substituents. This represents a monovalent group that is linked directly or via a linking group. m is an integer from 1 to 4. n is an integer between 1 and 6.

[0074] (Ar 1 ) The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 60, more preferably 6 to 30, and further Preferably, it is 6 to 18. Specifically, aromatic hydrocarbon groups include benzene rings, naphthium, etc. Talene ring, fluorene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, Lycene rings, pyrene rings, benzoanthracene rings, or perylene rings, etc., typically having 6 or more carbon atoms. Aromatic hydrocarbons, which are usually 30 or less, preferably 18 or less, and more preferably 14 or less. A divalent group in a ring structure, or multiple structures selected from these structures arranged in a chain or branched manner. Examples include the divalent groups of the bonded structure. When multiple aromatic hydrocarbon rings are linked, Examples include a structure consisting of 2 to 8 connected units, with a structure consisting of 2 to 5 connected units being preferable. When multiple hydrocarbon rings are linked together, the same structure may be linked, or different structures may be linked. That's fine.

[0075] The number of carbon atoms in the aromatic heterocyclic group is preferably 3 to 50, more preferably 3 to 30, and even more preferably The range is 3 to 18. Specifically, aromatic heterocyclic groups include triazine rings and pyrimyl groups. Zin ring, pyridine ring, benzofuran, benzothiophene, dibenzofuran, dibenzothio The number of carbon atoms in the phen, carbazole ring, etc. is usually 3 or more, usually 30 or less, preferably 18 or less. More preferably, a divalent group of an aromatic heterocyclic structure having 12 or fewer groups, or derived from these structures. Examples include divalent groups in structures where multiple selected structures are linked together in a chain or branched manner.

[0076] Ar 1 This refers to a divalent aromatic hydrocarbon having 6 to 60 carbon atoms, which may have substituents, or a substituted one. A divalent aromatic heterocyclic group with 3 to 50 carbon atoms that may have a group, selected as one or multiple Preferably, the group is a divalent group in which several groups are bonded directly or via linking groups, and it has hole transport properties. Since this improves the effect, the group that directly bonds to the nitrogen atom may have substituents. A fragrance hydrocarbon group is preferred, and as an aromatic hydrocarbon group, preferably 1 to 4 benzyl groups. A ring, one or two naphthalene rings, one or two fluorene rings, one or two multiple fe Multiple structures selected from a nanthrene ring and one tetraphenylene ring in any order A divalent group formed by chain-like or branched bonding, or a 1,4-phenylene group, 1,3 -These are a phenylene group, a 2,7-fluorenylene group, and a divalent spirobisfluorene group. More preferably, selected from 1 to 4 benzene rings and 1 or 2 fluorene rings. A divalent group formed by the linkage of multiple structures in any order, either in a chain or branched manner, and in particular Preferably, one or two phenylene groups, a 2,7-fluorenylene group, one or two phenylene groups Divalent groups in which nylene groups are linked in this order in a chain, such as phenylene groups, biphenylene groups, and parater groups. It is a phenylene group or a 2,7-fluorenylene group. The fluorene structure is at the 9,9' position. The molecule may have substituents, and the substituents that may be present are preferably groups selected from the substituent group Z. These aromatic hydrocarbon structures may have substituents. The substituents that may be present are as described above. Specifically, the substituents can be selected from the substituent group Z. Preferred substituents are the substituents. This is a preferred substituent of group Z.

[0077] (Ar 1 (Preferred range) Ar 1 From the viewpoint of the solubility and durability of polymer compounds, the following formulas (2-1) to (2-7 It is preferable to have at least one substructure selected from ).

[0078] [ka]

[0079] In each of the above equations (2-1) to (2-7), * represents a bond with an adjacent structure or water. Representing elementary atoms, at least one of the two * represents a bonding position with an adjacent structure, 4 Any two of the *existing* elements*, at least one of which represents a connection point with an adjacent structure. In the same manner as above, unless otherwise specified, the definition of * is the same.

[0080] (R 1 , R 2 ) R 1 , R 2 Each of these independently consists of an alkyl group having 6 to 12 carbon atoms, an alkenyl group, and an alkynyl group. Groups, alkoxy groups, aryloxy groups, alkoxycarbonyl groups, acyl groups, halogenated groups Child, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, cyano R represents a group, an aralkyl group, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. 1 , R 2 teeth They may bond together to form a ring. The aromatic hydrocarbon ring structure may be a phenyl group or a phenyl group. A group in which multiple lig groups are linked together is even more preferable.

[0081] These groups may have substituents. The substituents that may be present are as described above, specifically The substituent group Z can be selected from the substituent group Z or a bridging group. Preferably, the substituent group Z is preferred A C6-C50 aromatic hydrocarbon group that may have substituents or crosslinking groups, or a crosslinking group. . The substructure is more preferably a structure selected from equations (2-1) to (2-7). More preferably, the structure is selected from formulas (2-1) to (2-5), and is particularly preferred. This structure is selected from equations (2-1) to (2-4). Because of its excellent charge transport properties, It is most preferable that the substructures be represented by formulas (2-2) and (2-3).

[0082] The formula (2-1) is preferably a 1,3-phenylene group or a 1,4-phenylene group. ru. The equation (2-2) is preferably the following equation (2-2-2).

[0083] [ka]

[0084] More preferably than formula (2-2), the formula is (2-2-3) shown below.

[0085] [ka]

[0086] Furthermore, Ar 1 As a substructure, in equation (2-1) It is preferable to have the substructure represented by the given formula and the substructure represented by formula (2-2). Substructures having substructures represented by formula (2-1) and substructures having substructures represented by formula (2-2) In terms of structure, it consists of a substructure represented by formula (2-1) and a substructure represented by formula (2-2). The structure is one in which multiple structures are selected, chosen from equations (2-8) to (2-11) below. A substructure represented by at least one of the above is even more preferable.

[0087] [ka]

[0088] The substructure represented by equation (2-1) and the substructures represented by equations (2-3) and (2-4) The substructures it possesses are the substructure represented by equation (2-1) and equations (2-3), (2-4 A structure that includes multiple structures selected from substructures represented by the following equation (2-12)~ A substructure represented by at least one selected from the following formulas (2-15) is even more preferable. .

[0089] [ka]

[0090] (G) G represents a divalent group represented by any of the above formulas (1-1) to (1-3), and a substituent A is, independently, a fluorine atom, CF3, or SF5. From the viewpoint of not reducing charge transport capacity, substituent A is a fluorine atom, CF3 This is preferable. From the same viewpoint, it is preferable that m and n in equations (1-1) to (1-3) are integers between 1 and 2. .

[0091] (Ar 2 ) Ar 2 This includes substituent A, an aromatic hydrocarbon group having 6 to 60 carbon atoms which may have substituents, A 3-50 aromatic heterocyclic group which may have substituents, or which may have substituents A group selected from good aromatic hydrocarbon groups and aromatic heterocyclic groups which may have substituents is This represents a monovalent group that is linked together directly or via a linking group.

[0092] In the polymer compound used in the present invention, Ar 2 If multiple Ar 2 is the same It may be one or different. Examples of monovalent aromatic hydrocarbon groups include benzene rings, azulene rings, and naphthalene. Ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benz Pyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluor Examples include monovalent groups of six-membered rings, such as len rings, or 2- to 5-fused rings.

[0093] Examples of monovalent aromatic heterocyclic groups include furan rings, benzofuran rings, and thiophenes. Ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazo Indole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, Lollopyrrole ring, thienopyrrole ring, thienocyrrole ring, phlopyrrole ring, flofuran Ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimi Dazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, Noline ring, isoquinoline ring, synnoline ring, quinoxaline ring, phenanthidine ring, peri monocyclic or 2-4 fused rings of 5 or 6 members, such as quinazoline rings, quinazolinone rings, etc. A monovalent group is one example.

[0094] Examples of linking groups include oxygen atoms or carbonyl groups. Aromatic rings and non-conjugated structures By forming this structure, the triplet level can be increased, so the spaces between the phenylene rings A structure linked by oxygen atoms or carbonyl groups can also be used. Preferably, linked It is a structure that connects directly without an intermediary element. 1 The same applies to the linking group in this case. Among these, monovalent aromatic carbonized water is chosen due to its superior charge transport properties and durability. A phenyl group is preferred, a monovalent group of a benzene ring or fluorene ring is more preferred, and a phenyl group or A fluorenyl group is more preferable, a fluorenyl group is particularly preferable, and 2-fluorenyl The base is the most preferred.

[0095] Also, Ar 2 From the standpoint of solubility in the coating solvent, it is substituted with an alkyl group having 1 to 24 carbon atoms. A fluorenyl group is preferred, and a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms is preferred. The nyl group is particularly preferred. Furthermore, Ar 2 This is where an alkyl group is placed at the 9th position of the 2-fluorenyl group. A substituted 9-alkyl-2-fluorenyl group is preferred, and a 9-alkyl group with two alkyl groups substituted is preferred. The 9-dialkyl-2-fluorenyl group is particularly preferred. 2 is substituted with an alkyl group. The presence of a fluorenyl group is preferable because it improves solubility in the solvent. Aromatic hydrocarbon groups which may have substituents and aromatic heterogeneous groups which may have substituents As for monovalent groups formed by multiple groups selected from a ring group being linked directly or via linking groups, Multiple groups selected from the above aromatic hydrocarbon group and the above aromatic heterocyclic group are either directly or linked together. A monovalent group linked via a mediated linkage can be used.

[0096] (Specific example) The following are specific examples of repeating units represented by the above formula (1) used in the present invention, but It is not limited to these.

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] [Electron-accepting compounds] The organic field light-emitting element composition of the present invention is, when it is a hole injection / transport layer forming composition, Mashiku contains electron-accepting compounds. As electron-accepting compounds, they possess oxidizing power and can accept one electron from the hole injection / transport materials mentioned above. Compounds having the ability to do so are preferred. Specifically, compounds having an electron affinity of 4 eV or more. Compounds with an energy of 5 eV or higher are preferred, and compounds with an energy of 5 eV or higher are even more preferred.

[0102] Examples of electron-accepting compounds include, for example, 4-isopropyl-4'-methyldiphenyl Organic group-substituted onions such as iodonium tetrakis(pentafluorophenyl) borate Umium salt, iron(III) chloride (Japanese Patent Publication No. 11-251067), peroxodisulfate High-valence inorganic compounds such as monoium, cyano compounds such as tetracyanoethylene, tris( Aromatic boron such as pentafluorophenyl (borane) (Japanese Patent Publication No. 2003-31365) Examples include compounds, fullerene derivatives, and iodine.

[0103] Among the above compounds, onium salts substituted with organic groups, high-valent inorganic compounds, etc. are preferable in that they have a strong oxidizing power. Also, onium salts substituted with organic groups, cyano compounds, aromatic boron compounds, etc. are preferable in that they have high solubility in various solvents and are applicable for forming a film by a wet film-forming method. Specific examples of onium salts substituted with organic groups, cyano compounds, aromatic boron compounds, etc., which are preferable as the electron-accepting compound, are described in the pamphlet of International Publication No. 2005 / 089024, and the preferable examples are the same. For example, compounds represented by the following structural formulas are included, but are not limited thereto. As for the electron-accepting compound, one kind may be used alone, or two or more kinds may be used in any combination and ratio.

[0104] [Chemical formula]

[0105]

[0106] [Cation radical species] As the cation radical species, an ionic compound composed of a cation radical, which is a chemical species obtained by removing one electron from a hole injection / transport material, and a counter anion is preferable. However, when the cation radical is derived from a polymer compound having a hole transport ability, the cation radical has a structure obtained by removing one electron from the repeating unit of the polymer compound.

[0107] As the cation radical, it is preferable that it is a chemical species obtained by removing one electron from an organic polymer compound (1) as a hole injection / transport material. That the cation radical is a chemical species obtained by removing one electron from an organic polymer compound (1) is advantageous for amorphousness, visible light transmittance, heat resistance, and ​​​​​​​​​​​​ It is suitable in terms of solubility and other factors. Here, the cation radical species interacts with the organic polymer compound (1) and the aforementioned electron-accepting compound. It can be produced by mixing an organic polymer compound (1) and an electron acceptor. By mixing with an electron-accepting compound, electrons are transferred from the organic polymer compound (1) to the electron-accepting compound. A cation transfer occurs, and the cation radical and counter anion of the hole injection / transport material are formed. Ionic compounds are generated.

[0108] [organic solvent] As an organic solvent, it is possible to dissolve each component in the composition for the organic electroluminescent element well, and There are no restrictions on the type of substance, as long as it does not undergo undesirable chemical reactions with these components. A solvent that does not contain substances that may deactivate dikal species or substances that generate such substances is preferred. It seems so.

[0109] In relation to the above, examples of preferred solvents include ether-based solvents, ester-based solvents, and ketone-based solvents. At least one selected from the group consisting of solvents and hydrocarbon solvents is included. Specific examples of ether-based solvents include ethylene glycol dimethyl ether and ethylene glycol Licor diethyl ether, propylene glycol-1-monomethyl ether acetate Aliphatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and ani Sole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene Aromatic ethers such as ruene, 2,3-dimethylanisole, and 2,4-dimethylanisole These are some examples. Any one of these ether-based solvents may be used alone, or two or more. The above can be used in any combination and ratio.

[0110] Specific examples of ester solvents include ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate. -Butyl and other aliphatic esters; phenyl acetate, phenyl propionate, methyl benzoate, Examples include aromatic esters such as ethyl benzoate, propyl benzoate, and n-butyl benzoate. These ester solvents may be used individually or in any combination of two or more. They may be used in combinations and ratios.

[0111] Examples of ketone solvents include aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone. Examples include alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fencone. These ketone solvents may be used individually or in any combination of two or more. It may also be used in combinations and ratios. Examples of hydrocarbon solvents include toluene, xylene, mesitylene, and cyclohexylbenzene. (Phenylcyclohexane), tetralin, 3-isopropylbiphenyl, 1,2,3, Fragrances such as 4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene. Fragrance group hydrocarbon solvents; n-decane, cyclohexane, ethylcyclohexane, decalin, Examples include alkane solvents such as bicyclohexane. Any of these hydrocarbon solvents One type may be used alone, or two or more types may be used in any combination and ratio. Furthermore, one or more ether-based solvents and one or more ester-based solvents They may be used in any ratio. Also, one or more ether-based solvents Alternatively, one or more ketone solvents may be used in any ratio. , one or more ester solvents and one or more ketone solvents, any They may be used in combination at a ratio.

[0112] In addition to the above-mentioned ether solvents, ester solvents, ketone solvents, and hydrocarbon solvents Examples of solvents that can be used include amide solvents such as N,N-dimethylformamide and N,N-dimethyl acetamide; dimethyl sulfoxide and the like. Any one of these species may be used alone, or two or more species may be used in any combination and ratio. Also, One or more of these solvents may be used in combination with one or more of the above-mentioned ether solvents, ester solvents, ket one solvents, and hydrocarbon solvents. In particular, Aromatic hydrocarbon solvents such as benzene, toluene, and xylene have a low ability to dissolve oxidants and polymers, so they are preferably used in combination with ether solvents and ester solvents. Since they have a low ability to dissolve oxidants and polymers, it is preferable to use them in combination with ether solvents and ester solvents. Since the effect of solvating the electron-accepting compound is small and cation radical species are more likely to be generated from the organic polymer compound than from the electron-accepting compound, ether solvents and hydrocarbon solvents are preferred. Since the effect of solvating the electron-accepting compound is small and cation radical species are more likely to be generated from the organic polymer compound than from the electron-accepting compound, ether solvents and hydrocarbon solvents are preferred, and hydrocarbon solvents are more preferred.

[0113] [Content of each component] The content rate of the organic solvent in the composition of the present invention is usually 1% by mass or more, preferably 70% by mass % or more, and usually 99.999% by mass or less, preferably 99% by mass or less. If the content rate of the organic solvent is at least the above lower limit, the viscosity becomes low and the film-forming workability tends to be excellent. If it is at most the above upper limit, the film-forming efficiency is excellent. The content rate of the organic polymer compound (1) in the composition of the present invention is usually 0.001% by mass or more Preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and usually 50 A range of 15% by mass or less is desirable, preferably 20% by mass or less, and more preferably 15% by mass or less. It's nice.

[0114] If the content of organic polymer compound (1) is above the lower limit mentioned above, it is easier to form a uniform, flat film. If the viscosity is below the above upper limit, it will be low-viscosity and have excellent film-forming properties. The content of the electron-accepting compound in the composition of the present invention is usually 0.00001% by mass or more. Preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 50% by mass A range of less than or equal to a certain amount, usually less than or equal to 5% by mass, and more preferably less than or equal to 1% by mass, is desirable.

[0115] In particular, by mixing the organic polymer compound (1) of the present invention with an electron-accepting compound, Because a sufficient amount of cation radicals is efficiently generated, for organic polymer compound (1) The proportion of electron-accepting compounds is preferably 1% by mass or more, and more preferably 3% by mass or more. A concentration of 5% by mass or more is particularly preferred, 50% by mass or less is preferred, and 40% by mass or less is even more preferred. Furthermore, a concentration of 30% by mass or less is particularly preferred.

[0116] <Other ingredients> Furthermore, the composition of the present invention may contain other components other than those mentioned above. Examples of components include leveling agents and defoaming agents. Examples of leveling agents include silicone-based surfactants and fluorine-based surfactants. The leveling agent may be used individually or in any combination of two or more types. They may also be used in combination in a specific ratio.

[0117] If the composition of the present invention contains a leveling agent, its content is usually 0.0001 by mass. % or more, preferably 0.001% by mass or more, and usually 1% by mass or less, preferably 0.1 It is within the range of mass percent or less. If the leveling agent content is too low, leveling will be insufficient. There are some harmful effects, and if there is too much, it may inhibit the electrical properties of the film. Examples of defoaming agents include silicone oil, fatty acid esters, and phosphate esters. The defoaming agent may be used individually, or two or more may be used in any combination and ratio. They can also be used in combination as a percentage. If the composition of the present invention contains an antifoaming agent, its content is usually 0.0001% by mass or more. Preferably 0.001% by mass or more, and usually 1% by mass or less, preferably 0.1% by mass The range is as follows: If the amount of defoaming agent is too low, the defoaming effect may be lost, and if it is too high... Too much grease can sometimes impair the electrical properties of the film. <Reasons why it works> The charge-transport polymer compound according to this embodiment contains electron-withdrawing substituents including a fluorine atom. It possesses a deep ionization potential, and cation radicals are not easily generated in solution. In this embodiment, by using a low-polarity organic solvent, the organic solvent and the electron-accepting compound are... It is thought that the affinity decreases, causing electron-accepting compounds to accumulate near charge-transporting polymer compounds. Therefore, doping proceeds even in solution, and sufficient cation radicals are generated, which is desirable. It seems so.

[0118] [Organic electroluminescent element] The organic electroluminescent element of the present invention comprises a substrate, an anode, an organic layer, and a cathode provided on the substrate. An organic electroluminescent element comprising the above, wherein the organic layer is formed using the composition of the present invention. It encompasses a variety of things. The layer structure and formation method of the organic electroluminescent element of the present invention are described below with reference to Figure 1. I will explain it. Figure 1 is a schematic cross-sectional diagram showing an example of the structure of the organic electroluminescent element 10 of the present invention, and in Figure 1 1 is the substrate, 2 is the anode, 3 is the hole injection layer, 4 is the hole transport layer, 5 is the light-emitting layer, and 6 is the hole blocking layer. Layers 7, 8, and 9 represent the electron transport layer, electron injection layer, and cathode, respectively.

[0119] <Circuit board> The substrate serves as the support for the organic electroluminescent element and is typically made of quartz, glass, or metal. Plates, metal foils, or synthetic resins, i.e., plastic films or sheets, are used. These include glass sheets, polyester, polymethacrylate, and polycarbonate. A transparent synthetic resin film such as polysulfone is preferred. The substrate 1 is protected from the outside air. Since degradation of the electroluminescent element is less likely to occur, it is preferable to use a material with high gas barrier properties. In particular, when using materials with low gas barrier properties, such as synthetic resin substrates, the substrate 1 is small At the very least, it is preferable to improve gas barrier properties by providing a dense silicon oxide film or the like on one of the surfaces. It's nice.

[0120] <Anode> Anode 2 is responsible for injecting holes into the light-emitting layer. Anode 2 is usually made of aluminum. Metals such as gold, silver, nickel, palladium, and platinum; oxides of indium and / or tin, etc. Metal oxides; metal halides such as copper iodide; carbon black or poly(3-methyl It is composed of conductive polymers such as thiophene, polypyrrole, and polyaniline.

[0121] The formation of anode 2 is usually carried out by dry methods such as sputtering or vacuum deposition. These include metal nanoparticles such as silver, copper iodide, carbon black, and conductive metal oxides. When forming anode 2 using fine particles, conductive polymer fine powder, etc., an appropriate binder is used. It can also be formed by dispersing it in a resin solution and coating it onto a substrate 1. High conductivity In the case of molecules, thin films can be formed directly on the substrate by electrolytic polymerization, or conductive polymers can be applied to the substrate. Anode 2 can also be formed by coating or other means (Appl. Phys. Lett., 60 (Volume 2711, 1992).

[0122] The thickness of anode 2 should be determined according to the required transparency and material. If transparency is required, a thickness that allows for a visible light transmittance of 60% or more is preferable, and 80% or less is preferable. A higher thickness is even more preferable. The thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more. The wavelength is above 1000 nm, and is usually below 1000 nm, preferably below 500 nm. If transparency is not required, the thickness of anode 2 can be any thickness depending on the required strength, etc. In this case, the anode 2 may have the same thickness as the substrate 1. If the next layer is to be deposited on its surface after the formation of anode 2, UV light + O By applying treatments such as plasma, oxygen plasma, and argon plasma, impurities on the anode are removed. It is also preferable to adjust its ionization potential to improve hole injection capabilities. It seems so.

[0123] <Hole injection layer 3> The hole injection layer 3 is a layer that transports holes from the anode 2 to the light-emitting layer, and is usually formed on the anode 2. It will be done. The hole injection layer according to the present invention is formed by a wet deposition method using the organic electroluminescent element composition of the present invention. It is particularly preferable that it be formed. In this specification, wet film deposition refers to a film deposition method, i.e., a coating method, such as spin Coating method, dip coating method, die coating method, bar coating method, blade coating method, roll coating method Coating method, spray coating method, capillary coating method, inkjet method, nozzle printing Films are formed using wet methods such as tapping, screen printing, gravure printing, and flexographic printing. This refers to a method that employs certain techniques and then dries the films formed using these methods to complete the film formation process. The thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 The wavelength is less than or equal to nm, preferably less than or equal to 500 nm.

[0124] <Hole transport layer 4> The hole transport layer 4 is a layer that is responsible for transporting holes from the anode 2 side to the light-emitting layer 5 side. The transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, but it is connected from the anode 2 to the light-emitting layer 5. It is preferable to provide a hole transport layer 4 in order to enhance the function of transporting holes. In this case, the hole transport layer 4 is usually formed between the anode 2 and the light-emitting layer 5. There is a hole injection layer 3. In this case, the hole transport layer 4 is formed between the hole injection layer 3 and the light-emitting layer 5.

[0125] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and is usually 300 The size is less than or equal to nm, preferably less than or equal to 100 nm. The hole transport layer 4 can be formed by either vacuum deposition or wet deposition. (Advantage: Excellent film formation properties) From there, it is preferable to form the film by a wet deposition method. The hole transport layer 4 typically contains a hole-transporting compound that forms the hole transport layer 4. Among the hole-transporting compounds included in 4, in particular, 4,4'-bis[N-(1-naphthyl) Represented by -N-phenylamino]biphenyl, it contains two or more tertiary amines. Aromatic diamines in which a condensed aromatic ring is substituted with a nitrogen atom (Japanese Patent Publication No. 5-234681) , 4,4',4''-tris(1-naphthylphenylamino)triphenylamine, etc. Aromatic amine compounds having a terburst structure (J. Lumin., Vol. 72-74, 98) Page 5, 1997), Aromatic amine compounds consisting of a tetramer of triphenylamine (Che m.Commun., p. 2175, 1996), 2,2',7,7'-Tetrakis-( Spiro compounds such as diphenylamino)-9,9'-spirobifluorene (Synth.M etals, vol. 91, p. 209, 1997), 4,4'-N,N'-dicarbazole Examples include carbazole derivatives such as phenyl. Polyvinylcarbazole, polyvinyl Nyltriphenylamine (Japanese Patent Publication No. 7-53953), tetraphenylbenzidine Polyarylene ether sulfone (Polym.Adv.Tech., Vol. 7, 3 (Page 3, 1996), etc., can also be used.

[0126] <Emitting layer 5> The light-emitting layer 5 emits holes and cathodes injected from the anode 2 when an electric field is applied between the pair of electrodes. This layer is responsible for the function of emitting light when electrons injected from layer 9 recombine and become excited. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 9. If a hole injection layer 3 is present, holes are formed between the hole injection layer 3 and the cathode 9, and holes are transported onto the anode 2. If layer 4 is present, it is formed between the hole transport layer 4 and the cathode 9. The light-emitting layer 5 is made of a light-emitting material and It is preferable that both include charge-transporting materials. The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention, however, if defects occur in the film From the perspective of ease of operation, a thicker material is preferable, while from the perspective of easier operation with a low drive voltage, a thinner material is preferable. The film thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and usually 2 A wavelength of 00 nm or less is preferred, and 100 nm or less is even more preferred.

[0127] (Luminescent material) The light-emitting material used in the light-emitting layer 5 emits light at a desired emission wavelength and does not impair the effects of the present invention. There are no particular restrictions, and known light-emitting materials can be used. Examples of fluorescent materials include the following: Examples of fluorescent materials that emit blue light (blue fluorescent materials) include naphthalene, Perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl Examples include benzene and its derivatives. Examples of fluorescent materials that emit green light (green fluorescent materials) include quinacridone. Examples include derivatives, coumarin derivatives, and aluminum complexes such as Al(C9H6NO)3. ru.

[0128] Examples of fluorescent materials that emit yellow light (yellow fluorescent materials) include rubrene, pe Examples include limidone derivatives. Examples of fluorescent materials that emit red light (red fluorescent materials) include DCM(4- (dicyanomethylene)-2-methyl-6-(p-dimethy laminostyryl)-4H-pyran) compounds, benzopyran derivatives, rh Examples include damine derivatives, benzothioxanthene derivatives, and azabenzothioxanthene. .

[0129] Examples of phosphorescent materials include long-period periodic tables (hereinafter, unless otherwise specified, "periodic" refers to the periodic table). When referring to the "periodic table," it means the long-period type of periodic table. (Selected from groups 7-11) Examples include organometallic complexes containing metals. The metals are selected from groups 7 to 11 of the periodic table. Preferably, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium Examples include zinc, platinum, and gold.

[0130] Ligands for organometallic complexes include (hetero)arylpyridine ligands and (hetero)arylpyridine ligands. (Hetero)aryl groups such as arylpyrazole ligands and pyridine, pyrazole, phenant Ligands linked to lorine are preferred, and phenylpyridine ligands and phenylpyrazo A ligand is preferred. Here, (hetero)aryl group refers to an aryl group and a heteroaryl group. It represents at least one of the ion groups.

[0131] A preferred phosphorescent material is, specifically, tris(2-phenylpyridine)iridium Tris(2-phenylpyridine)ruthenium, Tris(2-phenylpyridine)para Dium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium Phenylpyridine complexes such as tris(2-phenylpyridine)rhenium and octaeth Platinum porphyrin, octaphenyl platinum porphyrin, octaethylpalladium porphyrin Examples include porphyrin complexes such as porphyrin and octaphenylpalladium porphyrin.

[0132] As for polymer-based luminescent materials, poly(9,9-dioctylfluorene-2,7-diyl ), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-( N-(4-sec-butylphenyl))diphenylamine), poly[(9,9-dioc) Tylfluoren-2,7-diyl)-co-(1,4-benzo-2{2,1'-3}-to Polyfluorene-based materials such as Riazol, poly[2-methoxy-5-(2-ethylhexyl] Polyphenylene vinylene-based materials such as [xyloxy)-1,4-phenylene vinylene] It can be listed.

[0133] In the organic electroluminescent device of the present invention, the light-emitting material contained in the light-emitting layer 5 is a low-molecular-weight, light-emitting material. Being a hybrid is preferable because it results in a narrow half-width and vivid luminescence. As for luminescent low molecular weight compounds, the molecular weight should be 5000 or less, especially 3000 or less, for example, 100~ A low molecular weight luminescent compound of about 2000 is preferred, specifically the aforementioned fluorescent luminescent material or phosphorescent compound. This includes luminescent materials. These luminescent low-molecular-weight compounds may be used individually or in combination of two or more. It may also be used in combinations and ratios.

[0134] (Charge transport material) Charge-transporting materials are materials that possess the ability to transport positive charges (holes) or negative charges (electrons). There are no particular restrictions as long as the effect of the invention is not impaired, and known materials can be used. The charge transport material is a compound that has been conventionally used in the light-emitting layer 5 of organic electroluminescent devices. It is possible to use such compounds, and in particular, compounds used as the host material for the light-emitting layer 5 are preferred. Specifically, charge transport materials include aromatic amine compounds and phthalocyanine compounds. Substances, porphyrin compounds, oligothiophene compounds, polythiophene compounds, bean Zylphenyl compounds, compounds in which tertiary amines are linked by a fluorene group, hydrazone compounds Substances, silazane compounds, silanamine compounds, phosphatamine compounds, quinacridone compounds Examples of hole-transporting compounds in the hole injection layer 3 of the composite include the compounds exemplified above. Anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, Electron transport of phenanthroline compounds, oxadiazole compounds, silole compounds, etc. Examples include chemical compounds.

[0135] As a charge transport material, 4,4'-bis[N-(1-naphthyl)-N-phenylamine It contains two or more tertiary amines, such as no]biphenyl, and two or more condensed aromatic rings with nitrogen Atom-substituted aromatic diamine (Japanese Patent Publication No. 5-234681), 4,4',4''- Tris(1-naphthylphenylamino)triphenylamine and other compounds with a starburst structure Aromatic amine compounds (J. Lumin., Vol. 72-74, p. 985, 1997) Aromatic amine compounds consisting of a triphenylamine tetramer (Chem.Commun ., p. 2175, 1996), 2,2',7,7'-tetrakis-(diphenylamino Fluorene compounds such as )-9,9'-spirobiflorene (Synth.Metals (Vol. 91, p. 209, 1997), 4,4'-N,N'-dicarbazole biphenyl Which of the carbazole compounds and other compounds exemplified as hole-transporting compounds in hole transport layer 4 It can also be used as a preferred alternative. In addition, 2-(4-biphenylyl)-5-(p-tacy (TBu-PBD), 2,5-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), Oxadiazoles such as su(1-naphthyl)-1,3,4-oxadiazole (BND) System compounds, 2,5-bis(6'-(2',2''-bipyridyl))-1,1-dimethyl- Silole compounds such as 3,4-diphenylsilole (PyPySPyPy), vasofena Trolin (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenate Examples include phenanthroline compounds such as basocupproine (BCP). . The above charge transport material is preferably used in a ratio of 1 to 100 times that of the light-emitting material. stomach.

[0136] (Formation of the light-emitting layer 5 by wet film deposition method) In the organic electroluminescent device of the present invention, the light-emitting material contained in the light-emitting layer 5 is highly purified. It is preferable that the compound be a luminescent low-molecular-weight compound because it is easily luminescent. In the organic electroluminescent element of the present invention, it is preferable to form the light-emitting layer 5 by a wet film deposition method. It seems so. When forming an emissive layer by a wet film deposition method, the material that will become the emissive layer 5 is usually dissolved in a solvent ( A composition for film formation (composition for forming an emissive layer) is prepared by mixing it with a solvent for the light layer, and this emissive layer shape The composition is placed on a layer below the light-emitting layer 5, usually on the hole transport layer 4 or the hole injection layer 3. The film is formed by a wet deposition method and then drying.

[0137] Examples of solvents for the light-emitting layer include ethylene glycol dimethyl ether and ethylene glycol Glycol diethyl ether, propylene glycol-1-monomethyl ether acetate ( Aliphatic ether solvents such as PGMEA; 1,2-dimethoxybenzene, 1,3-dimeth Xybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole , aromatic ether solvents such as diphenyl ether; phenyl acetate, phenyl propionate Aromatic compounds such as methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate. Ester solvents; toluene, xylene, mesitylene, cyclohexylbenzene, tetramethyl ,3-isopropylbiphenyl,1,2,3,4-tetramethylbenzene,1,4-di Aromatic hydrocarbon solvents such as isopropylbenzene and methylnaphthalene; N,N-dimethyl Amide solvents such as formamide and N,N-dimethylacetamide; n-decane, cyclohexamide Alkane solvents such as xane, ethylcyclohexane, decalin, and bicyclohexane; chloro Halogenated aromatic hydrocarbon solutions such as chlorobenzene, dichlorobenzene, and trichlorobenzene Agents; aliphatic alcohol solvents such as butanol and hexanol; cyclohexanol, cyclo Alicyclic alcohol solvents such as octanol; methyl ethyl ketone, dibutyl ketone, etc. Aliphatic ketone solvents; alicyclic ketones such as cyclohexanone, cyclooctanone, and fencone. Examples include alkane-based solvents, etc. Of these, alkane-based solvents and aromatic hydrocarbon-based solvents are particularly noteworthy. It is preferable.

[0138] To obtain a more uniform film, the solvent must evaporate from the liquid film immediately after deposition at an appropriate rate. This is preferable. For this reason, the boiling point of the solvent used is usually 80°C or higher, preferably 100°C or higher. More preferably 120°C or higher, usually 270°C or lower, preferably 250°C or lower, Preferably, the temperature is 230°C or lower. The amount of solvent used is arbitrary as long as it does not significantly impair the effects of the present invention, but the amount of solvent used for forming the light-emitting layer is arbitrary. The total content in the product is preferably high because its low viscosity makes film formation easier. A lower solvent content is preferable from the standpoint of easily forming a thick film. The solvent content is in the composition for forming the light-emitting layer. Preferably, 1% by mass or more, more preferably 10% by mass or more, and particularly preferably 50% by mass It is 1% by amount or more, preferably 99.99% by mass or less, more preferably 99.9% by mass or less. Particularly preferably, it is 99% by mass or less.

[0139] For removing the solvent after wet film formation, heating or reduced pressure can be used. As a heating method used in the field, since heat is applied evenly to the entire film, Clean Orb Hmm, a hot plate is preferable. The heating temperature in the heating process is arbitrary as long as it does not significantly impair the effects of the present invention, however, dry From the standpoint of shortening the drying time, a higher temperature is preferable, and from the standpoint of causing less damage to the material, A lower temperature is preferable. The upper limit of the heating temperature is usually 250°C or less, preferably 200°C or less. More preferably, the temperature is 150°C or lower. The lower limit of the heating temperature is usually 30°C or higher. The temperature is preferably 50°C or higher, and more preferably 80°C or higher. By keeping it below the above upper limit... Therefore, the temperature becomes lower than the heat resistance of commonly used charge transport materials or phosphorescent materials, and decomposes. This can suppress crystallization. By setting the heating temperature above the lower limit, the removal of the solvent is possible. This can avoid prolonged heating times. The heating time in the heating process is controlled by the composition for forming the light-emitting layer. It is appropriately determined by the boiling point and vapor pressure of the solvent, the heat resistance of the material, and the heating conditions.

[0140] <Hole Blocking Layer 6> A hole blocking layer 6 may be provided between the light-emitting layer 5 and the electron injection layer 8 described later. This is a layer that is laminated on top of the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 9 side. The hole blocking layer 6 plays the role of preventing holes moving from the anode 2 from reaching the cathode 9. It also plays a role in efficiently transporting electrons injected from the cathode 9 toward the light-emitting layer 5. The required properties for the material constituting the blocking layer 6 are high electron mobility and low hole mobility. This is because the energy gap, i.e., the difference between HOMO and LUMO, is large, and the excitation is three One characteristic is a high multiplet level (T1).

[0141] Examples of materials for the hole blocking layer 6 that satisfy these conditions include bis(2-methyl-8) -Quinolinolate)(phenolate)aluminum, bis(2-methyl-8-quinolinolate) (Triphenylsilanolato)aluminum mixed ligand complex, bis(2-methyl-8- Aluminum-μ-oxo-bis-(2-methyl-8-quinolinolato)aluminum Metal complexes such as nium dinuclear metal complexes, styryl compounds such as distyryl biphenyl derivatives (special (Publication No. 11-242996), 3-(4-biphenylyl)-4-phenyl-5(4 Triazole derivatives such as (-tert-butylphenyl)-1,2,4-triazole (specifically) Japanese Patent Publication No. 7-41759), phenanthroline derivatives such as basocproine (Japanese Patent Publication No. 10 Examples include (Publication No. 79297). (As described in International Publication No. 2005 / 022962) Compounds having at least one pyridine ring substituted at positions 2, 4, and 6 also contribute to the hole inhibition layer 6. It is a desirable material.

[0142] There are no restrictions on the method of forming the hole blocking layer 6; it can be formed in the same manner as the method of forming the light-emitting layer 5 described above. It is possible. The thickness of the hole-blocking layer 6 is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 0. The wavelength is 3 nm or greater, preferably 0.5 nm or greater, and usually 100 nm or less, preferably 50 nm. It is less than or equal to m.

[0143] <Electron transport layer 7> The electron transport layer 7 aims to further improve the current efficiency of the device, and is positively charged to the light-emitting layer 5 or It is provided between the pore element layer 6 and the electron injection layer 8. The electron transport layer 7 efficiently transports electrons injected from the cathode 9 between electrodes where an electric field is applied. It is formed from a compound that can transport electrons in the direction of the light-emitting layer 5. Used in the electron transport layer 7. As for electron-transporting compounds, those that have high electron injection efficiency from the cathode 9 or electron injection layer 8 are... Furthermore, it is a compound that has high electron mobility and can efficiently transport injected electrons. It is necessary to do so.

[0144] Examples of electron-transporting compounds that satisfy these conditions include 8-hydroxyquinoline. Metal complexes such as aluminum complexes (Japanese Patent Publication No. 59-194393), 10-hydro Xybenzo[h]quinoline metal complex, oxadiazole derivative, distyrylbiphenyl Derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone gold Group complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimid Zolylbenzene (U.S. Patent No. 5645948), quinoxaline compounds (Japanese Patent Publication No. 6 -Publication No. 207169), phenanthroline derivatives (Japanese Patent Publication No. Hei 5-331459), 2-t-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated non Examples include crystalline silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

[0145] The thickness of the electron transport layer 7 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm. The wavelength is less than or equal to m, preferably less than or equal to 100 nm. The electron transport layer 7 is formed in the same manner as the light-emitting layer 5 by a wet deposition method or a vacuum deposition method. Alternatively, it is formed by laminating onto the hole blocking layer 6. Vacuum deposition is usually the most commonly used method. It can be done.

[0146] <Electron injection layer 8> The electron injection layer 8 efficiently transfers electrons injected from the cathode 9 to the electron transport layer 7 or the light-emitting layer 5. It serves the role of injecting. To efficiently perform electron injection, the material forming the electron injection layer 8 should be a metal with a low work function. It is preferable to use alkali metals such as sodium and cesium, and varium. Alkaline earth metals such as chlorine and calcium are used.

[0147] The film thickness of the electron injection layer 8 is preferably 0.1 to 5 nm. At the interface between the cathode 9 and the electron transport layer 7, an electron injection layer 8 is provided, consisting of LiF, MgF2, Li2O, Inserting an ultrathin insulating film, such as Cs2CO3, with a thickness of approximately 0.1 to 5 nm, is also possible for the device. This is an effective method to improve efficiency (Appl. Phys. Lett., Vol. 70, 15 2 pages, 1997; Japanese Patent Application Publication No. 10-74586; IEEE Trans.Elect ron.Devices, vol. 44, p. 1245, 1997; SID 04 Diges t, 2004, p. 154).

[0148] Furthermore, nitrogen-containing heterocyclic compounds such as bathophenanthroline and 8-hydroxyquinoline Sodium and potassium are used in organic electron transport materials, such as metal complexes including luminium complexes. , doping with alkali metals such as cesium, lithium, and rubidium (Japanese Patent Publication No. 10-270) Japanese Patent Publication No. 171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482 (As described in, etc.) By improving electron injection and transport properties, it is possible to achieve both excellent film quality and improved electron injection and transport properties. Therefore, this is preferable. In this case, the film thickness is usually 5 nm or more, preferably 10 nm or more. The wavelength is typically 200 nm or less, preferably 100 nm or less. The electron injection layer 8 is deposited in the same manner as the light-emitting layer 5 by a wet deposition method or a vacuum deposition method, Alternatively, it is formed by laminating it onto a hole blocking layer 6 or electron transport layer 7. The details for the wet film deposition method are the same as those for the light-emitting layer 5 described above.

[0149] <Cathode 9> The cathode 9 plays the role of injecting electrons into the electron injection layer 8 or the light-emitting layer 5, or other layers on the light-emitting layer 5 side. In addition, the material used for the anode 2 can be used as the material for the cathode 9. However, in order to efficiently perform electron injection, it is preferable to use a metal with a low work function, for example. For example, metals such as tin, magnesium, indium, calcium, aluminum, silver, or These alloys are used. For example, magnesium-silver alloy is used as the material for cathode 9. Low work function alloy electrodes such as magnesium-indium alloys and aluminum-lithium alloys These are some examples.

[0150] In terms of the stability of the element, a metal layer with a high work function and stability to the atmosphere is placed on top of the cathode 9. It is preferable to stack the metals to protect the cathode 9, which is made of a metal with a low work function. Examples of such metals include aluminum, silver, copper, nickel, chromium, gold, and platinum. It can be done. The film thickness of the cathode is usually the same as that of anode 2.

[0151] <Other component layers> The above explanation has mainly focused on the layered element shown in Figure 1, but the organic electroluminescent element according to this embodiment Between the anode 2 and cathode 9 and the light-emitting layer 5 in the child, as long as their performance is not impaired, the above explanation In addition to the brightly lit layer, any other layer may be present, and any layer other than the light-emitting layer 5 may be omitted. You may do so.

[0152] For example, an electron blocking layer may be provided between the hole transport layer 4 and the light-emitting layer 5 for a similar purpose to the hole blocking layer 8. It is also effective to do this. The electron blocking layer blocks electrons moving from the light-emitting layer 5 to the hole transport layer 4. By preventing it from reaching the target, the probability of recombination with holes in the light-emitting layer 5 is increased, and the generated Its role is to confine excitons within the light-emitting layer 5 and to efficiently emit holes injected from the hole transport layer 4. It plays a role in transporting light in the direction of the optical layer 5.

[0153] The properties required for an electron stopping layer include high hole transport and energy gap, so to speak. This is due to the large difference between HOMO and LUMO levels, and the high excited triplet level (T1). It can be done. When the light-emitting layer 5 is formed by a wet deposition method, the electron blocking layer is also formed by a wet deposition method. This is preferable because it facilitates the production of offspring.

[0154] Therefore, it is preferable that the electron blocking layer also has suitability for wet film deposition, and such electron blocking The materials used for the layers include dioctyl fluorene, represented by F8-TFB, and truffles. Examples include copolymers of phenylamines (International Publication No. 2004 / 084260). The structure is the opposite of that in Figure 1, i.e., cathode 9, electron injection layer 8, electron transport layer 7, hole blocking on substrate 1. It is also possible to stack the layers in the following order: layer 6, light-emitting layer 5, hole transport layer 4, hole injection layer 3, and anode 2. Furthermore, the organic electric field generator according to this embodiment is placed between two substrates, at least one of which is highly transparent. It is also possible to incorporate optical elements.

[0155] The structure shown in Figure 1 consists of multiple layers stacked together, that is, a structure in which multiple light-emitting units are stacked together. It is also possible to do so. In that case, instead of the interstage interface layer, that is, the interface layer between the light-emitting units, For example, using V2O5 as a charge generation layer reduces the barriers between stages, improving luminous efficiency and driving performance. More preferable from a voltage standpoint. The interface layer is, for example, when the anode is ITO and the cathode is Al. This refers to those two layers. The present invention relates to an organic field light-emitting element consisting of a single element or an element arranged in an array. This applies to any structure in which the anode and cathode are arranged in an XY matrix. It is possible.

[0156] [OLED display] The organic EL display of the present invention has an organic electroluminescent element of the present invention. There are no particular restrictions on the type or structure of the EL display, and the present invention provides an organic electroluminescent element. It can be assembled using the usual methods.

[0157] For example, "Organic EL Display" (Ohmsha, published August 20, 2004, by Shizuka Tokito) The present invention's organic EL display is produced in the manner described in (by Chihaya Adachi and Hideyuki Murata). Rays can be formed. [Examples]

[0158] The present invention will be described in more detail below with reference to examples. The present invention is described in the following examples. The present invention is not limited to this, and can be modified and implemented in any way without departing from its essence. .

[0159] [Example 1] As a hole injection layer forming composition, a repeating structure represented by the following formula (P-1) is used. 3.0% by mass of a pore-transporting polymer compound and an electron-accepting compound represented by the following formula (HI-1) A composition was prepared by dissolving 0.6% by mass of the substance in phenylcyclohexane.

[0160] [ka]

[0161] [Example 2] As a hole injection layer forming composition, a repeating structure represented by the above formula (P-1) is used. 3.0% by mass of a pore-transporting polymer compound and an electron-accepting compound represented by the above formula (HI-1) A composition was prepared by dissolving 0.6% by mass of the substance in anisole.

[0162] [Comparative Example 1] As a hole injection layer forming composition, a repeating structure represented by the above formula (P-1) is used. 3.0% by mass of a pore-transporting polymer compound and an electron-accepting compound represented by the above formula (HI-1) A composition was prepared by dissolving 0.6% by mass of the substance in ethyl benzoate. [Comparative Example 2] As a hole injection layer forming composition, a repeating structure represented by the above formula (P-1) is used. A composition was prepared by dissolving 3.0% by mass of a pore-transporting polymer compound in phenylcyclohexane. It was made.

[0163] [Measurement of absorbance] Absorbance of the prepared hole injection layer forming composition at a wavelength of 500 nm (absorbance (500 )), and absorbance at a wavelength of 800 nm (absorbance (800)) were measured using a spectrophotometer U-3 Measurements were taken using a 900H (manufactured by Hitachi). The measurement conditions were as follows: Measurement conditions: Measurement mode: Wavelength scan Data mode: Abs Starting wavelength: 1000nm Termination wavelength: 200nm Scan speed: 300nm / min Sampling interval: 0.50 nm Slit: 5nm Light source switching wavelength: 340nm Cell length: 10mm For reference measurements, the organic solvent contained in each hole injection layer forming composition was used. The measurement results are shown in Table 1.

[0164] [Table 1]

[0165] As shown in the results in Table 1, the hole injection layer forming compositions of Examples 1 and 2 had an absorbance of (500 The coefficient of charge transport is 0.2 or higher, and the absorbance (800) is 0.05 or higher, and the coefficient of charge transport is necessary for improving charge transport. Sufficient on-radicals are generated, hole transport is high, and low-voltage driving of organic electroluminescent devices is achieved. This shows that it is possible to extend the lifespan. In contrast, the hole injection layer forming compositions of Comparative Examples 1 and 2 also showed absorbance (500) (800) is also a very small value, and is the amount of cation radicals generated that is necessary for improving charge transport. There are few. [Example 3] A hole-only device (hereinafter referred to as HOD) was fabricated using the following method. A transparent conductive film of indium tin oxide (ITO) is deposited to a thickness of 50 nm on a glass substrate. The deposited material (Geomatec Co., Ltd., sputter-deposited product) is processed using conventional photolithography techniques. The anode was formed by patterning a 2mm wide stripe using hydrochloric acid etching. The substrate with the ITO pattern formed on it was ultrasonically cleaned with a surfactant aqueous solution and then washed with ultrapure water. The cleaning process involves rinsing with water, ultrasonic cleaning with ultrapure water, rinsing with ultrapure water, and then drying with compressed air. Finally, we performed UV ozone cleaning. As a hole injection layer forming composition, a repeating structure represented by formula (P-1) is used. 3.0% by mass of a pore-transporting polymer compound and an electron-accepting compound represented by the above formula (HI-1) A composition was prepared by dissolving 0.6% by mass of the substance in phenylcyclohexane. This solution is spin-coated onto the substrate in air, and then heated on a hot plate in air for 95°C. The material was dried at °C for 30 minutes to form a uniform thin film with a thickness of 100 nm, which served as the hole injection layer. Next, the compound represented by the following formula (HT-1) is deposited onto the hole injection layer by vacuum deposition at a rate of 1 Å / Co-deposition was performed at a speed of seconds to form a hole transport layer with a thickness of 40 nm.

[0166] [ka]

[0167] Next, a 2mm wide striped shadow mask is used as a mask for cathode deposition, and the anode... The ITO stripes were placed in close contact with the substrate, perpendicular to each other, and then installed in a separate vacuum deposition apparatus. Then, the silver is heated using a molybdenum boat, and a film thickness of 80 Å is deposited at a rate of 1-8.6 Å / sec. A nanometer-thick silver layer was formed to create the cathode. In this manner, HOD was obtained. [Example 4] As a hole injection layer forming composition, a repeating structure represented by formula (P-1) is used. 3.0% by mass of a pore-transporting polymer compound and an electron-accepting compound represented by the above formula (HI-1) A composition obtained by dissolving 0.6% by mass of the substance in anisole instead of phenylcyclohexane. The HOD was prepared in the same manner as in Example 3, except for the materials used. [Comparative Example 3] As a hole injection layer forming composition, a repeating structure represented by formula (P-1) is used. A composition was prepared by dissolving 3.0% by mass of a pore-transporting polymer compound in phenylcyclohexane. Except for the above, the HOD was prepared in the same manner as in Example 3. [HOD's evaluation] For the HODs obtained in Examples 3 and 4 and Comparative Example 3, the current density was 10 mA / cm². 2 and The voltage was measured when a current was applied in a specific way. The measurement results are shown in Table 2.

[0168] [Table 2]

[0169] As shown in Table 2, the composition used in Comparative Example 3 was determined from the absorbance measurement results of Comparative Example 2. As is clear, the absorbance values ​​(500) and (800) are very small, indicating charge transport properties. Because it uses a composition that generates less cation radicals necessary for improvement, the device's low voltage Pressure-driven operation and extending the lifespan are difficult. In contrast, in Examples 3 and 4, low-voltage operation is possible. [Explanation of Symbols]

[0170] 1 circuit board 2 Anode 3. Hole injection layer 4. Hole transport layer 5. Emitting layer 6. Hole blocking layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 10 Organic electroluminescent element

Claims

1. 1. A composition for organic electroluminescent elements, comprising an organic polymer compound having a repeating unit represented by the following formula (1) and an organic solvent, wherein the composition has an absorbance of 0.2 or more at an optical path length of 10 mm and a wavelength of 500 nm, and an absorbance of 0.05 or more at an optical path length of 10 mm and a wavelength of 800 nm: 【Chemistry 1】 (In formula (1), Ar １ represents a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, a divalent aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent or aromatic heterocyclic groups which may have a substituent are linked together directly or via a linking group, G represents a phenylene group or a naphthylene group containing the substituent A of formula (1-1), A is F, CF ３ , SF ５ is. Ar ２ represents A, or a monovalent group in which a plurality of groups selected from an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, an optionally substituted aromatic heterocyclic group having 3 to 50 carbon atoms, and an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked together directly or via a linking group; m is an integer from 1 to 4, n is an integer from 1 to 6.

2. 2. The composition for organic electroluminescent devices according to claim 1, wherein the organic solvent contains at least one of an ether-based solvent, a ketone-based solvent, and a hydrocarbon-based solvent.

3. The composition for organic electroluminescent devices according to claim 1 , wherein the absorptions at 500 nm and 800 nm are derived from cation radical species.

4. An organic electroluminescent device comprising a substrate, and an anode, an organic layer, and a cathode provided on the substrate, wherein the organic layer comprises an organic layer formed using the composition for organic electroluminescent devices according to any one of claims 1 to 3.

5. 5. The organic electroluminescent device according to claim 4, wherein the organic layer includes a light-emitting layer, and the light-emitting layer is formed by a wet film-forming method.

6. 6. The organic electroluminescent device according to claim 5, wherein the light-emitting layer contains a light-emitting low-molecular-weight compound.

7. An organic EL display comprising the organic electroluminescent element described in claim 4.

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