JP4815830B2 - Organic electroluminescent device, organic electroluminescent device manufacturing method and image display medium - Google Patents

Description

  The present invention relates to an organic electroluminescent device that emits light by converting electric energy into light, a method for manufacturing the organic electroluminescent device, and an image display medium, and in particular, a display device, electronic paper, a backlight, an illumination light source, and an electrophotographic exposure. The present invention relates to an organic electroluminescent element that can be suitably used in the fields of devices, signs, signboards, and the like, a method for producing the organic electroluminescent element, and an image display medium.

An electroluminescent element is a self-luminous all-solid-state element, has high visibility and is resistant to impact, and thus is widely expected to be applied. Currently, those using inorganic phosphors are the mainstream and widely used. However, since driving requires an AC voltage of 200 V or higher and 50 to 1000 Hz, the running cost is high and the luminance is insufficient. Has a problem. On the other hand, research on electroluminescent devices using organic compounds first started with a single crystal such as anthracene, but the film thickness was as thick as about 1 mm and a driving voltage of 100 V or more was required. For this reason, attempts have been made to reduce the thickness by vapor deposition (see, for example, Non-Patent Document 1).
The light emission of these elements is such that electrons are injected from one of the electrodes and holes are injected from the other electrode, so that the light emitting material in the element is excited to a high energy level, and the excited illuminant becomes the base. This is a phenomenon in which excess energy for returning to the state is emitted as light. However, the driving voltage is still as high as 30 V, the density of electron / hole carriers in the film is low, and the photon generation probability due to carrier recombination is low, so that sufficient luminance cannot be obtained, leading to practical use. There wasn't.

However, in 1987, Tang et al., A functionally separated organic electric field in which a hole transporting organic low molecular weight compound and a fluorescent organic low molecular weight compound having an electron transporting ability were sequentially stacked on a transparent substrate by a vacuum deposition method. There has been reported a light-emitting element that can obtain high luminance of 1000 cd / m ² or more at a low voltage of about 10 V (for example, see Patent Document 1 or Non-Patent Document 2). Since then, research and development of organic electroluminescent devices has been actively conducted.
These electroluminescent elements having a stacked structure are structures in which an organic light emitter and a charge transporting organic substance (charge transport material) are stacked on an electrode, and each hole and electron moves through the charge transport material and is regenerated. Emits light when bonded. As the organic light emitter, an organic dye emitting fluorescence such as 8-quinolinol aluminum complex or coumarin compound is used. Examples of the charge transport material include diamino compounds such as N, N-di (m-tolyl) N, N′-diphenylbenzidine and 1,1-bis [N, N-di (p-tolyl) aminophenyl] cyclohexane, 4- (N, N-diphenyl) aminobenzaldehyde-N, N-diphenylhydrazone compound and the like.

Organic electroluminescent devices using these organic compounds have high emission characteristics, but have problems in thermal stability and storage stability during light emission. A layer formed of an organic material of an electroluminescent element is very thin, tens to hundreds of nanometers, and a voltage applied per unit thickness is very high, and is driven at a high current density of several mA / cm ^2. Therefore, a large amount of Joule heat is generated. For this reason, hole transporting low molecular weight compounds and fluorescent organic low molecular weight compounds formed in an amorphous glass state by vapor deposition gradually crystallize as the temperature rises and finally melt, resulting in a decrease in luminance and dielectric breakdown. Many phenomena were observed, and as a result, the lifetime of the device was reduced.
This low thermal stability is believed to be due to the low glass transition temperature of the material. That is, many low molecular weight compounds have low melting points and high symmetry. Therefore, in order to solve the problem relating to thermal stability, N, N-di (1-naphthyl) N, N′— introduced with an α-naphthyl group that improves the glass transition temperature and obtains a stable amorphous glass state is obtained. An organic electroluminescent device using diphenylbenzidine has been reported (for example, see Non-Patent Document 3). In addition, an organic electroluminescent element using starburst amine has been reported for the same purpose (for example, see Non-Patent Document 4).
However, since these materials alone have an energy barrier due to the ionization potential of the hole transport material, they do not satisfy the hole injection property from the anode or the hole injection property to the light emitting layer. Furthermore, in the two-layered element structure of the hole transport layer and the light emitting layer, an interdiffusion phenomenon occurs and the light emission efficiency is lowered. Also, during device fabrication, considerable heat is applied during fabrication processes such as vapor deposition, baking, annealing, wiring, and sealing, and thermal stability is ensured enough to withstand changes over time due to prolonged use. Therefore, improvement of the glass transition temperature in a further material is desired.

On the other hand, research and development have also been conducted on electroluminescent devices using polymer materials instead of low molecular compounds, and conductive polymer devices such as poly (p-phenylene vinylene) (for example, Non-Patent Document 5 or Patent Document 2). ), A polymer device in which triphenylamine is introduced into the side chain of polyphosphazene (see, for example, Non-Patent Document 6), a device in which an electron transport material and a fluorescent dye are mixed in a hole transporting polyvinyl carbazole ( For example, see Non-Patent Document 7).
Although these have a relatively high glass transition point compared to low molecular weight compounds, poly (p-phenylene vinylene) is heat-treated after spin coating of a soluble precursor, so that defects occur in the main chain conjugated polymer. Easily reduces the light emission characteristics. Phosphazene has a problem that the ionization potential is high and the charge injection characteristic is lowered. Polyvinylcarbazole has a high glass transition point, but when trapped by impurities or when a low molecular weight compound is mixed into a polymer, the low molecular weight acts as a plasticizer, and the brightness and luminous efficiency are still low. It does not reach the laminated type field emission device using a compound.

In addition, as a manufacturing method, a coating method is desirable from the viewpoint of simplification of manufacturing, workability, large area, cost, and the like, and it has been reported that an element can be obtained by a casting method (for example, Non-Patent Document 8). Or see 9.). However, since the charge transport material has poor solubility and compatibility with solvents and resins, it is easy to crystallize and has defects in production or characteristics.
JP 59-194393 A Japanese Patent Laid-Open No. 10-92576 Thin Solid Films, 94, 171 (1982) Appl. Phys. Lett. , 51, 913 (1987) IEICE technical report, OME95-54 (1995) Proceedings of the 40th Joint Conference on Applied Physics 30a-SZK-14 (1993) Nature, 357, 477 (1992) 42nd Polymer Symposium Proceedings 20J21 (1993) Proceedings of the 38th Joint Conference on Applied Physics 31p-G-12 (1991) Proceedings of the 50th Japan Society of Applied Physics, 29p-ZP-5 (1989) Proceedings of the 51st Japan Society of Applied Physics, 28a-PB-7 (1990)

  It is an object of the present invention to solve the problems in the prior art and achieve the following objects. That is, using a charge transporting polyester excellent in thermal stability during storage, storage stability, solubility in solvents and resins and compatibility, it has high emission intensity, high emission efficiency, long device life, and production It is an object of the present invention to provide an easy organic electroluminescence device, a method for producing the same, and an image display medium using the organic electroluminescence device.

  As a result of earnest studies on the charge transporting polymer to achieve the above object, a charge comprising a repeating unit containing at least one selected from the structures represented by the following general formulas (I-1) and (I-2) as a partial structure The present inventors have found that the transportable polyester has charge injection characteristics, charge mobility, thin film forming ability, and light emission characteristics suitable as an organic electroluminescence device, and has completed the present invention.

  That is, the organic electroluminescent element of the present invention comprises a pair of electrodes composed of an anode and a cathode, at least one of which is transparent or translucent, and one or a plurality of organic compound layers sandwiched between the pair of electrodes. It is an organic electroluminescent device configured, wherein at least one of the organic compound layers is a repeating structure containing at least one selected from the structures represented by the following general formulas (I-1) and (I-2) as a partial structure It contains at least one kind of charge transporting polyester composed of units.

(In the general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings. Represents a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, and in the general formula (I-1), k is 0 Or i represents 0, j represents 1, and in the general formula (I-2), k represents 0, i represents 1, j represents 1 , and T represents 1 carbon. Represents a divalent straight chain hydrocarbon group of ˜6 or a divalent branched hydrocarbon group of 2 to 10 carbon atoms, Ar is represented by the following general formula (II ) in the case of general formula (I-1): -1) or (II-2), and in the case of general formula (I-2), it represents a substituent represented by the following general formula (II-1) .

(In the general formula (II-1) or (II-2), Ar ₁ represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic carbon having 2 to 10 aromatic rings. Represents hydrogen, a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted divalent aromatic heterocyclic ring, and R ₁ and R ₂ each independently represent a hydrogen atom, Represents an alkyl group, a cyano group, a halogen atom, a substituted amino group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group, wherein each R ₂ in the general formulas (II-1) and (II-2) is all It may be a hydrogen atom or a combination of a hydrogen atom and another substituent, q is 0, and when Ar in the general formula (I-1) is a substituent represented by the general formula (II-1) r is 0 or 1, and Ar in the general formula (I-1) is represented by the general formula (II- In the case of the substituent represented by 2), r represents 0, and in the case of the general formula (I-2), r represents 0 .

Examples of the charge transporting polyester according to the present invention include polyesters represented by the following general formula (III-1 ) .

(In the general formula _(III-1), A 1 represents at least one selected from structures represented by the general formula (I-1) and (I-2), the divalent Y ₁ are each independently an organic Represents a group, m represents 1, and p represents an integer of 5 to 5000.)

  The organic compound layer constituting the organic electroluminescent device of the present invention is roughly classified into a single layer configuration composed only of a light emitting layer having a charge transport function, or a mutual structure including at least a light emitting layer or a light emitting layer having a charge transport function. It has a function-separated type multi-layer structure composed of a plurality of layers having different functions. For example, [1] light-emitting layer and electron transport layer (hereinafter may be abbreviated as “layer structure (1)”), [2] hole transport layer, light-emitting layer, and electron. Transport layer (hereinafter sometimes abbreviated as “layer configuration (2)”), [3] Hole transport layer and light-emitting layer having a charge transport function (hereinafter sometimes abbreviated as “layer configuration (3)”) Is mentioned. In this configuration, the hole injection layer is included in the hole transport layer, and the electron injection layer is included in the electron transport layer. The layer configuration is not limited to this.

When the organic compound layer is composed only of a light emitting layer having a charge transport function, the light emitting layer having the charge transport function has a structure represented by the general formulas (I-1) and (I-2). A charge transporting polyester comprising a repeating unit containing at least one selected from the above as a partial structure.
On the other hand, when the organic compound layer is composed of a plurality of functionally separated layers, in the layer structure (1), the charge transporting polyester is contained in at least one of the light emitting layer and the electron transport layer, and the layer structure In (2), the charge transporting polyester is contained in at least one layer of the light emitting layer, the hole transport layer, and the electron transport layer, and in the layer configuration (3), the hole transport layer and the light emitting layer having a charge transport function. The charge transporting polyester is contained in at least one of the above. In the present invention, the charge transporting polyester is preferably contained in a light emitting layer or a light emitting layer having a charge transport function. Thereby, charge injection characteristics, charge mobility, thin film forming ability, and light emission characteristics suitable for an organic electroluminescence device can be obtained.
The organic compound layer may further contain a charge transport material (hole transport material, electron transport material) other than the charge transport polyester.

  According to the present invention, using a charge transporting polyester excellent in thermal durability, solubility in solvents and resins, and compatibility, high brightness, high efficiency, long device life and few defects such as pinholes, large area It is possible to provide an organic electroluminescent device that can be easily manufactured, a method for producing the same, and an image display medium using the organic electroluminescent device.

Hereinafter, the organic electroluminescent device, the method for producing the organic electroluminescent device, and the image display medium of the present invention will be described in detail.
<Organic electroluminescent device>
The organic electroluminescent element of the present invention comprises a pair of electrodes consisting of an anode and a cathode, at least one of which is transparent or translucent, and one or a plurality of organic compound layers sandwiched between the pair of electrodes. An organic electroluminescent device, wherein at least one of the organic compound layers comprises a repeating unit containing at least one selected from the structures represented by the following general formulas (I-1) and (I-2) as a partial structure: It contains at least one kind of charge transporting polyester.

(In the general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings. Represents a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, k, i and j each independently represents 0 or 1; T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched hydrocarbon group having 2 to 10 carbon atoms, Ar represents the following general formula (II-1) Or represents a substituent represented by (II-2).)

(In the general formula (II-1) or (II-2), Ar ₁ represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic carbon having 2 to 10 aromatic rings. Represents hydrogen, a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted divalent aromatic heterocyclic ring, and R ₁ and R ₂ each independently represent a hydrogen atom, An alkyl group, a cyano group, a halogen atom, a substituted amino group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group, q and r each independently represent an integer of 0 to 10)

  The charge transporting polyester according to the present invention is excellent in thermal stability during light emission, solubility in solvents and resins, and phase solubility, and the organic electroluminescent device of the present invention contains the charge transporting polyester. Since the organic compound layer is formed, the emission intensity is high, the emission efficiency is high, the device life is long, and the manufacture is easy.

In general formulas (II-1) and (II-2), the polynuclear aromatic hydrocarbon and condensed aromatic hydrocarbon selected as the structure representing Ar ₁ are not particularly limited. In addition, in the present invention, the polynuclear aromatic hydrocarbon and the condensed aromatic hydrocarbon mean specifically defined as follows.

That is, the “polynuclear aromatic hydrocarbon” refers to a hydrocarbon in which two or more aromatic rings composed of carbon and hydrogen are present and the rings are bonded by a carbon-carbon bond. Specific examples include biphenyl and terphenyl.
“Condensed aromatic hydrocarbon” refers to a hydrocarbon in which two or more aromatic rings composed of carbon and hydrogen are present, and the rings share a pair of carbon atoms. Specific examples include naphthalene, anthracene, phenanthrene and fluorene.

  In addition, the number of atoms (Nr) constituting the ring skeleton of the heterocyclic ring is preferably Nr = 5 and / or 6. The type and number of atoms (heterogeneous atoms) other than carbon atoms constituting the ring skeleton are not particularly limited. For example, a sulfur atom, a nitrogen atom, an oxygen atom and the like are preferably used, and two types are included in the ring skeleton. The above and / or two or more different atoms may be contained. In particular, as a heterocyclic ring having a 5-membered ring structure, thiophene, pyrrole, oxazole and furan, or a heterocyclic ring in which the carbons at the 3rd and 4th positions of the polynuclear aromatic hydrocarbon and the condensed aromatic hydrocarbon are replaced with nitrogen are as follows. Pyridine, pyrazine and the like are preferably used as a heterocyclic ring which is preferably used and has a 6-membered ring structure.

Examples of the substituent on the benzene ring, polynuclear aromatic hydrocarbon, condensed aromatic hydrocarbon or aromatic heterocyclic ring of Ar ₁ include a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a substituted amino group, a halogen atom, etc. Is mentioned.
As an alkyl group, a C1-C10 thing is preferable, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group etc. are mentioned.
As an alkoxy group, a C1-C10 thing is preferable, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group etc. are mentioned.
As the aryl group, those having 6 to 20 carbon atoms are preferable, and examples thereof include a phenyl group and a toluyl group.
As the aralkyl group, those having 7 to 20 carbon atoms are preferable, and examples thereof include a benzyl group and a phenethyl group.
Examples of the substituent of the substituted amino group include an alkyl group, an aryl group, an aralkyl group, and the like, and specific examples are as described above.

  In the general formulas (I-1) and (I-2), X is a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, Represents a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, specifically, the following formulas (1) to (13) A group selected from:

In the formula, R ₃ to R ₁₈ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted aralkyl group. Or a halogen atom, a represents 0 or 1, and b represents an integer of 0 to 10.
V represents a group selected from the following formulas (14) to (34).

In the formula, R ₂₀ to R ₂₁ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, Or a halogen atom, R ₁₉ represents a hydrogen atom, an alkyl group or a cyano group, b represents an integer of 1 to 10, and c represents an integer of 0 to 10.

In the general formulas (I-1) and (I-2), T is a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched hydrocarbon having 2 to 10 carbon atoms. Represents a group. Preferably, it is selected from a divalent linear hydrocarbon group having 2 to 6 carbon atoms or a divalent branched hydrocarbon group having 3 to 7 carbon atoms. In addition, when j is 0 in the general formulas (I-1) and (I-2), it means that T does not exist in the general formulas (I-1) and (I-2).
A specific structure is shown below.

  Hereinafter, specific examples of the structure represented by the general formula (I-1) are shown in Tables 1 to 64, and specific examples of the structure represented by the general formula (I-2) are shown in Tables 65 to 119. The invention is not limited by the following specific examples.

  As the charge transporting polyester comprising a repeating unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure, the following general formula (III-1) or (III -2) is preferably used.

In the general formulas (III-1) and (III-2), A ₁ represents at least one selected from the structures represented by the general formulas (I-1) and (I-2). Two or more types of structures A ₁ may be included. Y ₁ and Z ₁ each independently represent a divalent organic group, m represents an integer of 1 to 5, and p represents an integer of 5 to 5000.

Specific examples of Y ₁ and Z ₁ include groups selected from the following formulas (35) to (40).

In the formula, R ₂₂ and R ₂₃ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or A halogen atom, d and e each independently represent an integer of 1 to 10, f independently represents an integer of 0, 1 or 2; h and i each independently represents 0 or 1; V has the same meaning as described above.

  The weight average molecular weight Mw of the charge transporting polyester comprising a repeating unit containing at least one selected from the structures represented by formulas (I-1) and (I-2) as a partial structure used in the present invention is 5000 to 5000. What exists in the range of 3000000 is preferable, 10000-1 million are further more preferable, and 10000-500000 are especially preferable. When the weight average molecular weight Mw is in the range of 5,000 to 300,000, thermal durability, solubility in solvents and resins, and compatibility are excellent, and defects such as pinholes can be reduced.

  Specific examples of the charge transporting polyester represented by the general formulas (III-1) and (III-2) are shown below, but the present invention is not limited to these specific examples. The numbers in the monomer column in the table correspond to the structure numbers which are specific examples of the structures represented by the general formulas (I-1) and (I-2). Moreover, m means m in general formula (III-1) and (III-2). Hereinafter, specific examples (compounds) assigned with respective numbers, for example, specific examples assigned number 15 are referred to as exemplary compounds (15).

The method for synthesizing the charge transporting polyester used in the present invention can be used in combination with known methods depending on the desired structure, and is not particularly limited, but as a specific example, the general formula (I- A charge transporting polyester comprising a repeating unit containing at least one selected from the structures represented by 1) and (I-2) as a partial structure is represented by the general formula (III-1) or (III-2). The case of such polyester will be described in detail below.
When the charge transporting polyester used in the present invention is a polyester represented by the general formula (III-1) or (III-2), a monomer represented by the following general formula (I-3) is used: For example, it can be synthesized by polymerization by a known method described in the 4th edition, Experimental Chemistry Course Vol. 28 (Maruzen, 1992).

In General Formula (I-3), A ₁ represents at least one selected from the structures represented by General Formulas (I-1) and (I-2), and A ′ represents a carboxyl group or a halogenated group. An acyl group or a group —CO ₂ —R ₂₄ is represented, and R ₂₄ represents an alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group.
That is, the polyester represented by the general formula (III-1) or (III-2) can be synthesized as follows.

(1) When A ′ is a carboxyl group, a dihydric alcohol represented by HO— (Y ₁ —O) m—H is mixed with the monomer in an equivalent amount and polymerized using an acid catalyst. As the acid catalyst, those used for usual esterification reaction such as sulfuric acid, toluenesulfonic acid, trifluoroacetic acid and the like can be used, and 1 / 10,000 to 1/10 parts by mass, preferably 1 part by mass of monomer. It is used in the range of 1/1000 to 1/50 parts by mass. In order to remove water generated during the polymerization, it is preferable to use a solvent that can be azeotroped with water, and toluene, chlorobenzene, 1-chloronaphthalene and the like are effective, and 1 to 100 parts by weight per 1 part by weight of the monomer. It is used in the range of part by mass, preferably 2-50 parts by mass. The reaction temperature can be arbitrarily set, but it is preferable to carry out the reaction at the boiling point of the solvent in order to remove water generated during the polymerization.

  When the solvent is not used after completion of the reaction, it is dissolved in a soluble solvent. When a solvent is used, the reaction solution is dropped as it is in a poor solvent in which alcohols such as methanol and ethanol and polymers such as acetone are difficult to dissolve, to precipitate the polyester, and after separating the polyester, Wash thoroughly with organic solvent and dry. Further, if necessary, the reprecipitation treatment in which the polyester is precipitated by dissolving in an appropriate organic solvent and dropping in a poor solvent may be repeated. The reprecipitation treatment is preferably carried out with efficient stirring with a mechanical stirrer or the like. The solvent for dissolving the polyester in the reprecipitation treatment is used in the range of 1 to 100 parts by mass, preferably 2 to 50 parts by mass with respect to 1 part by mass of the polyester. The poor solvent is used in an amount of 1 to 1,000 parts by weight, preferably 10 to 500 parts by weight, based on 1 part by weight of the polyester.

2) When A ′ is an acyl halide group, a dihydric alcohol represented by HO— (Y ₁ —O) m—H is mixed with the monomer in an equivalent amount, and an organic basic catalyst such as pyridine or triethylamine is added. Use to polymerize. An organic basic catalyst is used in 1-10 equivalent with respect to 1 equivalent of monomers, Preferably it is 2-5 equivalent. As the solvent, methylene chloride, tetrahydrofuran (THF), toluene, chlorobenzene, 1-chloronaphthalene and the like are effective, and in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight with respect to 1 part by weight of the monomer. Used. The reaction temperature can be arbitrarily set. After the polymerization, reprecipitation treatment is performed as described above, and purification is performed.

  In the case of dihydric alcohols with high acidity such as bisphenol, an interfacial polymerization method can also be used. That is, it can polymerize by adding a dihydric alcohol to water, adding an equivalent base and dissolving it, and then adding a monomer solution equivalent to the dihydric alcohol with vigorous stirring. Under the present circumstances, water is used in 1-1,000 mass parts with respect to 1 mass part of dihydric alcohol, Preferably it is 2-500 mass parts. As the solvent for dissolving the monomer, methylene chloride, dichloroethane, trichloroethane, toluene, chlorobenzene, 1-chloronaphthalene and the like are effective. The reaction temperature can be arbitrarily set, and in order to promote the reaction, it is effective to use a phase transfer catalyst such as an ammonium salt or a sulfonium salt. The phase transfer catalyst is used in an amount of 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass, with respect to 1 part by mass of the monomer.

3) When A ′ is a group —CO ₂ —R _24, an excessive amount of a dihydric alcohol represented by HO— (Y ₁ —O) m—H is added to the monomer, and inorganic acids such as sulfuric acid and phosphoric acid are added. It can be synthesized by transesterification by heating an acid, titanium alkoxide, acetate or carbonate such as calcium and cobalt, or oxide of zinc or lead as a catalyst. The dihydric alcohol is used in the range of 2 to 100 equivalents, preferably 3 to 50 equivalents, with respect to 1 equivalent of the monomer. The catalyst is used in a range of 1 / 10,000 to 1 part by weight, preferably 1 / 1,000 to 1/2 part by weight, based on 1 part by weight of the monomer. The reaction is carried out at a reaction temperature of 200 to 300 ° C. After completion of the transesterification from the group —CO ₂ —R ₂₄ to the group —O— (Y ₁ —O) m—H, HO— (Y ₁ —O) m In order to promote polymerization due to elimination of -H, it is preferable to carry out the reaction under reduced pressure. Also, HO- (Y ₁ -O) m-H is removed azeotropically under normal pressure using a high boiling point solvent such as 1-chloronaphthalene that can be azeotroped with HO- (Y ₁ -O) m-H. Can also be reacted.

(4) Moreover, polyester can be synthesize | combined as follows. In each of the above cases, a compound represented by the following general formula (I-4) was produced by adding an excess of a dihydric alcohol and reacting, and then the compound was represented by the above general formula (I-3). What is necessary is just to make it react with a bivalent carboxylic acid or a bivalent carboxylic acid halide etc. by the method similar to the above using it instead of a monomer, and, thereby, polyester can be obtained.

However, in the general formula (I-4), A ₁ represents at least one selected from structures represented by the general formula (I-1) and (I-2), Y ₁ is a divalent organic group M represents an integer of 1 to 5.
Further, any molecule may be introduced into the terminal of the charge transporting polyester. In that case, the following method is mentioned. That is, when the terminal of the charge transporting polyester is a hydroxyl group, a monocarboxylic acid as a terminal-introducing compound may be copolymerized, or the electron transporting compound after the polymerization reaction of the polymer may be charged and reacted for introduction. it can.
When the terminal of the charge transporting polyester is a carboxyl group, the terminal-introducing compound monoalcohol can be copolymerized, or the electron transporting compound after the polymerization reaction of the polymer can be charged and reacted for introduction.
When the terminal of the charge transporting polyester is an acyl halide group, the monoacid chloride of the terminal introduction compound is copolymerized, or after the polymerization reaction of the polymer, the monoacid chloride of the terminal introduction compound is charged and reacted for introduction. be able to.
When the terminal of the charge transporting polyester is a group —CO ₂ —R ₂₄ , the terminal introduction compound monoester is copolymerized, or after the polymerization reaction of the polymer, the terminal introduction compound monoester is charged and reacted to introduce. can do.

Next, the layer structure of the organic electroluminescent element of the present invention will be described in detail.
The organic electroluminescent element of the present invention comprises a pair of electrodes composed of an anode and a cathode, at least one of which is transparent or translucent, and one or a plurality of organic compound layers including a light emitting layer sandwiched between the pair of electrodes, The layer structure is not particularly limited as long as the organic compound layer contains the charge transporting polyester as described above.

In the organic electroluminescence device of the present invention, when the organic compound layer is a single layer, the organic compound layer means a light emitting layer having a charge transport function, and the light emitting layer having the charge transport function contains the charge transporting polyester. To do.
On the other hand, when the organic compound layer has a multi-layer structure (that is, in the case of a function separation type in which each layer has a different function), at least one of the layers is a light emitting layer, and this light emitting layer is a light emitting layer having a charge transport function. There may be. In this case, as a specific example of the layer configuration composed of the light emitting layer or the light emitting layer having the charge transport function and other layers, a layer composed of a light emitting layer, an electron transport layer and / or an electron injection layer Configuration (1), layer configuration (2), hole transport layer and / or hole transport layer and / or hole injection layer, light emitting layer, electron transport layer and / or electron injection layer Examples include a layer configuration (3) composed of a hole injection layer and a light emitting layer, and layers other than the light emitting layer having the layer configurations (1) to (3) and the light emitting layer having a charge transport function are charge transporting. It functions as a layer or a charge injection layer.
In any one of the layer configurations (1) to (3), the charge transporting polyester may be contained in any one layer, but the charge is added to the light emitting layer or the light emitting layer having a charge transport function. It is preferable to contain transportable polyester.
In addition, the light-emitting layer, the hole transport layer, the hole injection layer, the electron transport layer, and the electron injection layer having a charge transport function are charge transport compounds other than the charge transport polyester (hole transport material, electron transport material). May further be included. Details of such a charge transporting compound will be described later.

Hereinafter, although the organic electroluminescent element of this invention is demonstrated in detail, referring drawings, this invention is not limited to this.
1 to 4 are schematic cross-sectional views for explaining the layer structure of the organic electroluminescent element of the present invention. In the case of FIGS. 1, 2, and 4, the organic compound layer is composed of a plurality of layers. FIG. 3 shows an example of the case where the organic compound layer is composed of one layer. In FIG. 1 to FIG. 4, components having similar functions are described with the same reference numerals.

  The organic electroluminescent element shown in FIG. 1 is obtained by laminating a transparent electrode 2, a light emitting layer 4, an electron transport layer and / or an electron injection layer 5, and a back electrode 7 on a transparent insulator substrate 1 in this order. However, when the layer denoted by reference numeral 5 is composed of an electron transport layer and an electron injection layer, the electron transport layer, the electron injection layer, and the back electrode 7 are laminated in this order on the back electrode 7 side of the light emitting layer 4. .

  The organic electroluminescent device shown in FIG. 2 has a transparent electrode 2, a hole transport layer and / or a hole injection layer 3, a light emitting layer 4, an electron transport layer and / or an electron injection layer 5 on the transparent insulator substrate 1. The back electrode 7 is laminated in this order. However, when the layer denoted by reference numeral 3 is composed of a hole transport layer and a hole injection layer, the hole injection layer, the hole transport layer, and the light emitting layer 4 are provided on the back electrode 7 side of the transparent electrode 2. Laminated sequentially. When the layer denoted by reference numeral 5 is composed of an electron transport layer and an electron injection layer, the electron transport layer, the electron injection layer, and the back electrode 7 are laminated in this order on the back electrode 7 side of the light emitting layer 4. .

  The organic electroluminescent device shown in FIG. 3 is obtained by laminating a transparent electrode 2, a light emitting layer 6 having a charge transport function, and a back electrode 7 on a transparent insulator substrate 1 in this order.

  The organic electroluminescent element shown in FIG. 4 is obtained by laminating a transparent electrode 2, a hole transport layer and / or a hole injection layer 3, a light emitting layer 4, and a back electrode 7 in this order on a transparent insulator substrate 1. is there. However, when the layer denoted by reference numeral 3 is composed of a hole transport layer and a hole injection layer, the hole injection layer, the hole transport layer, and the light emitting layer 4 are provided on the back electrode 7 side of the transparent electrode 2. Laminated sequentially.

Each will be described in detail below.
In the case of the layer configuration of the organic electroluminescent element shown in FIGS. 1 to 4, the transparent insulator substrate 1 is preferably transparent in order to extract emitted light, and glass, plastic film or the like is used. The term “transparent” means that the light transmittance in the visible region is 10% or more, and the transmittance is preferably 75% or more. The transparent electrode 2 is transparent in order to extract emitted light in the same manner as the transparent insulator substrate, and has a high work function for injecting holes, and preferably has a work function of 4 eV or more.
As specific examples, an oxide film such as indium tin oxide (ITO), tin oxide (NESA), indium oxide, zinc oxide, indium zinc oxide, and gold, platinum, palladium, or the like deposited or sputtered is used. The sheet resistance of the electrode is desirably as low as possible, preferably several hundred Ω / □ or less, and more preferably 100 Ω / □ or less. Further, like the transparent insulator substrate, it is preferable that the light transmittance in the visible region is 10% or more, and the transmittance is 75% or more.

  Further, for the purpose of improving the durability of the organic electroluminescent device or improving the luminous efficiency, hole transport other than the charge transporting polyester for adjusting the hole mobility with respect to the charge transporting polyester used in the present invention. The material may be formed by mixing and dispersing the material in the range of 0.1% by mass to 50% by mass. Examples of such hole transporting materials include tetraphenylenediamine derivatives, triphenylamine derivatives, carbazole derivatives, stilbene derivatives, aryl hydrazone derivatives, and porphyrin compounds, but they have good compatibility with charge transporting polyesters. , Tetraphenylenediamine derivatives and triphenylamine derivatives are preferred.

Similarly, when adjusting the electron mobility, the electron transport material may be mixed and dispersed in the range of 0.1% by mass to 50% by mass with respect to the charge transporting polyester. Such electron transport materials include oxadiazole derivatives, nitro-substituted fluorenone derivatives, diphenoquinone derivatives, thiopyran dioxide oxide derivatives, silole derivatives, chelate-type organometallic complexes, polynuclear or condensed aromatic ring compounds, perylene derivatives, triazole derivatives, full Examples include olenylidene methane derivatives.
Further, when both the hole mobility and the electron mobility need to be adjusted, both the hole transport material and the electron transport material may be mixed together in the charge transporting polyester.

Furthermore, an appropriate resin (polymer) or an additive may be added to improve film formability and prevent pinholes. Specific resins include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, cellulose resin, urethane resin, epoxy resin, polystyrene resin, polyvinyl acetate resin, styrene butadiene copolymer, vinylidene chloride-acrylonitrile. Copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, silicone resins, poly-N-vinyl carbazole resins, polysilane resins, polythiophenes, polypyrrole, and other conductive resins can be used. Moreover, as an additive, a well-known antioxidant, a ultraviolet absorber, a plasticizer, etc. can be used.
In order to improve the charge injection property, a hole injection layer and / or an electron injection layer may be used. As the hole injection material, a phenylenediamine derivative, a phthalocyanine derivative, an indanthrene derivative, a polyalkylene diester, An oxythiophene derivative or the like is used. These may be mixed with a Lewis acid, a sulfonic acid, or the like. As the electron injection material, metals such as Li, Ca, and Sr, metal fluorides such as LiF and MgF ₂ , and metal oxides such as MgO, Al ₂ O ₃ , and LiO are used.

  Further, when the charge transporting polyester is used for a function other than the light emitting function, a light emitting compound is used as a light emitting material. As the light-emitting material, a compound that exhibits high emission quantum efficiency in a solid state is used. The light-emitting material may be either a low molecular compound or a high molecular compound. Preferred examples of organic low molecular compounds include chelate-type organometallic complexes, polynuclear or condensed aromatic ring compounds, perylene derivatives, coumarin derivatives, and styrylarylene derivatives. In the case where a silole derivative, an oxazole derivative, an oxathiazole derivative, an oxadiazole derivative or the like is a polymer, a polyparaphenylene derivative, a polyparaphenylene vinylene derivative, a polythiophene derivative, a polyacetylene derivative, or the like is used. As preferable specific examples, the following light emitting materials (IV-1) to (IV-17) are used, but are not limited thereto. In the luminescent materials (IV-13) to (IV-17), V represents the functional group shown above, and n and g each represents 1 or an integer of 2 or more.

  Further, for the purpose of improving the durability of the device or improving the light emission efficiency, the light emitting material or the charge transporting polyester may be doped with a dye compound different from the light emitting material as a guest material. The doping ratio of the dye compound is about 0.001% to 40% by mass, preferably about 0.001% to 10% by mass. As the dye compound used for such doping, an organic compound that has good compatibility with the light emitting material and the charge transporting polyester and does not prevent the formation of a good thin film of the light emitting layer is used, preferably a coumarin derivative, DCM derivatives, quinacridone derivatives, rubrene derivatives, porphyrin derivatives, metal complex compounds such as Ir, Eu, and Pt are used. Preferable specific examples include the following dye compounds (V-1) to (V-6), but are not limited thereto.

In the case of the layer configuration of the organic electroluminescent device shown in FIGS. 1 to 4, the back electrode 7 is made of a metal, metal oxide, metal fluoride, etc., which can be vacuum-deposited and has a low work function for performing electron injection. Is done. Examples of the metal include magnesium, aluminum, gold, silver, indium, lithium, calcium, and alloys thereof. Examples of the metal oxide include lithium oxide, magnesium oxide, aluminum oxide, indium tin oxide, tin oxide, indium oxide, zinc oxide, and indium zinc oxide. Examples of the metal fluoride include lithium fluoride, magnesium fluoride, strontium fluoride, calcium fluoride, and aluminum fluoride. Further, a protective layer may be provided on the back electrode 7 in order to prevent deterioration of the organic electroluminescent element due to moisture or oxygen.
Specific examples of the protective layer material include metals such as In, Sn, Pb, Au, Cu, Ag, and Al, metal oxides such as MgO, SiO ₂ , and TiO ₂ , polyethylene resins, polyurea resins, and polyimide resins. A vacuum deposition method, a sputtering method, a plasma polymerization method, a CVD method, and a coating method can be applied to the formation of the protective layer including a resin.

The organic electroluminescent elements shown in FIGS. 1 to 4 are manufactured by sequentially forming individual layers on the transparent electrode 2 in accordance with the layer configuration of each organic electroluminescent element.
The film thicknesses of the hole transport layer and / or the hole injection layer 3, the light emitting layer 4, the electron transport layer and / or the electron injection layer 5, and the light emitting layer 6 having a charge transport function are each 10 μm or less, particularly 0. A range of 001 to 5 μm is preferable. The dispersion state of each of the materials (the charge transporting polyester, the light emitting material, etc.) may be a molecular dispersion state or a fine particle state such as a microcrystal. In the case of a film forming method using a coating solution, it is necessary to select a dispersion solvent in consideration of the dispersibility and solubility of each material in order to obtain a molecular dispersion state. In order to disperse into fine particles, a ball mill, a sand mill, a paint shaker, an attritor, a homogenizer, an ultrasonic method, or the like can be used.

The hole transport layer and / or hole injection layer 3, the light-emitting layer 4, the electron transport layer and / or the electron injection layer 5 or the light-emitting layer 6 having a charge transport function, which are organic compound layers, are prepared by vacuuming the above materials. Vapor deposition method, or dissolved or dispersed in a suitable organic solvent, and applied to the transparent electrode using the obtained coating solution for organic compound layer by spin coating method, ink jet method, cast method, dipping method, etc., and dried It is formed by doing.
In the manufacturing method of the organic electroluminescent element of this invention, it is preferable to have at least the application | coating process which apply | coats the coating liquid for organic compound layers by the inkjet method. That is, an image forming technique based on ink jet recording that is used in an ink jet printer can be used to form an organic compound layer.

  In the case of using the inkjet method, the organic compound layer coating liquid is used instead of the ink, and the droplet-shaped organic compound layer coating liquid is ejected from the nozzle of the droplet ejection head, thereby obtaining a desired position on the substrate. In addition, an organic compound layer having a desired film thickness and shape can be formed.

In addition, as a droplet discharge head, the same basic configuration and principle as those of a recording head used in an ink jet printer can be used. That is, by applying an external stimulus such as pressure or heat to the organic compound layer coating liquid, a method of discharging the organic compound layer coating liquid from a nozzle in a droplet form (piezo ink jet method using a piezoelectric element, heat A thermal ink jet method using a boiling phenomenon) can be used.
However, in the production of the organic electroluminescent device of the present invention, the external stimulus is more preferably pressure than heat. When the external stimulus is heat, the inkjet printing process involves the formation (solidification) of a coating film by discharging the organic compound layer coating liquid from the nozzle and volatilizing the solvent of the organic compound layer coating liquid that has landed on the substrate. In this case, since the viscosity of the coating solution for organic compound layer is largely changed by heat, it may be difficult to control the leveling property and patterning accuracy. In addition to this, charge transporting polyesters that are inferior in heat resistance cannot be used, and material options may be narrowed.

  Moreover, as an apparatus used for manufacturing the organic electroluminescent element of the present invention using the inkjet method, in addition to the above-described liquid droplet ejection head, for example, an organic electroluminescent element is formed as necessary. A fixing or conveying means for the substrate or the like, or a droplet discharge head scanning means for scanning the droplet discharge head with respect to the substrate plane direction may be provided.

The composition and properties of the organic compound layer coating solution are not particularly limited, but the viscosity of the organic compound layer coating solution is preferably within a range of 0.01 to 1000 cps at 25 ° C. , Preferably in the range of 1-100 cps.
When the viscosity is less than 0.01 cps, the coating solution for the organic compound layer that has landed on the substrate is likely to spread in the plane direction of the substrate, and it becomes difficult to control the film thickness or the patterning accuracy deteriorates. There is. Moreover, when the viscosity exceeds 1000 cps, the viscosity of the organic compound layer coating solution is too high, and it may be liable to cause ejection failure.
The viscosity of the coating solution for the organic compound layer is controlled by controlling the content of the charge transporting polyester, other additive components added as necessary, the molecular weight of the charge transporting polyester, and the like. Can be adjusted to the value.

<Image display medium>
The image display medium of the present invention is characterized in that the organic electroluminescent elements of the present invention are arranged in a matrix form and / or a segment form. In the present invention, when the organic electroluminescent elements are arranged in a matrix, only the electrodes may be arranged in a matrix, or both the electrodes and the organic compound layer may be arranged in a matrix. . In the present invention, when organic electroluminescent elements are arranged in segments, only the electrodes may be arranged in segments, or both electrodes and organic compound layers may be arranged in segments. Also good.
A matrix-like or segment-like organic compound layer can be easily formed by using the ink jet method described above.
A conventionally known device can be used as a driving device and a driving method for the matrix organic electroluminescent device and the segment organic electroluminescent device.

Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention.
Example 1
ITO (manufactured by Sanyo Vacuum Co., Ltd.) formed on the transparent insulating substrate was patterned by photolithography using a strip-shaped photomask and further etched to form a strip-shaped ITO electrode (width 2 mm). Next, the ITO glass substrate was washed with neutral detergent, pure water, acetone (for electronics industry, manufactured by Kanto Chemical) and isopropanol (for electronics industry, manufactured by Kanto Chemical) for 5 minutes each, and then spinned. It was dried with a coater.
A 5 mass% dichloroethane solution of charge transporting polyester [Exemplary Compound (3)] is prepared, filtered through a 0.1 μm PTFE filter, and then a thin film having a thickness of 0.050 μm as a hole transporting layer on the substrate by dipping. Formed. The said exemplary compound (IV-1) was vapor-deposited as a luminescent material, and the 0.055-micrometer-thick luminescent layer was formed. Subsequently, using a metallic mask provided with a strip-shaped hole, this mask is finally installed, and a Mg-Ag alloy is vapor-deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm by ITO. It formed so that it might cross | intersect an electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

(Example 2)
A dichloroethane solution containing 1 part by mass of charge transporting polyester [Exemplary Compound (11)], 4 parts by mass of poly (N-vinylcarbazole) and 0.005 parts by mass of the Exemplified Compound (IV-1) was prepared. Filtered with a PTFE filter. Using this solution, a thin film having a thickness of about 0.15 μm was formed as a light emitting layer on an ITO glass substrate etched and washed in the same manner as in Example 1 by a spin coater method. After sufficiently drying, a Mg—Ag alloy was vapor-deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

(Example 3)
A thin film having a thickness of 0.050 μm made of a charge transporting polyester [Exemplary Compound (12)] was formed as a hole transport layer on the ITO glass substrate etched and washed in the same manner as in Example 1 as in Example 1. The exemplary compound (IV-1), the exemplary compound (V-1) and (mass ratio 100: 1) are 0.065 μm in thickness as the light emitting layer, and the exemplary compound (IV-9) is as the electron transport layer in thickness. It was formed at 0.030 μm. Subsequently, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

Example 4
A thin film having a thickness of 0.050 μm made of a charge transporting polyester [Exemplary Compound (34)] was formed as a hole transport layer on the ITO glass substrate etched and washed in the same manner as in Example 1 by the inkjet method. As the light emitting layer, the exemplified compound (IV-17) (specifically, poly (9,9-dioctylfluorene-co-bithiophene), weight average molecular weight 75000) and the exemplified compound (V-5) (mass ratio 100: 1) was formed by a spin coater method with a thickness of 0.065 μm. After sufficiently drying, a back electrode having a width of 2 mm and a total thickness of 0.23 μm was formed so as to intersect the ITO electrode by vapor-depositing Ca to a thickness of 0.08 μm and Al to a thickness of 0.15 μm. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

(Example 5)
An organic electroluminescent device was produced in the same manner as in Example 2 except that the exemplified compound (41) was used instead of the exemplified compound (11) used in Example 2.

(Example 6)
An organic electroluminescent device was produced in the same manner as in Example 3, except that the exemplified compound (56) was used instead of the exemplified compound (3) used in Example 1.

(Example 7)
An organic electroluminescent device was produced in the same manner as in Example 3 except that the exemplified compound (39) was used instead of the exemplified compound (3) used in Example 1.

(Example 8)
An organic electroluminescent device was produced in the same manner as in Example 3, except that the exemplified compound (69) was used instead of the exemplified compound (3) used in Example 1.

Example 9
A 1.5 mass% dichloroethane solution of the charge transporting polyester [Exemplary Compound (15)] was prepared, and filtered through a 0.1 μm PTFE filter. Using this solution, a thin film having a thickness of about 0.05 μm was formed on an ITO glass substrate etched and washed in the same manner as in Example 1 by the ink jet method. Using the exemplified compound (IV-14) (n = 8, weight average molecular weight 30000) as a light emitting material, a light emitting layer having a thickness of 0.050 μm was formed by an ink jet method. After sufficiently drying, a back electrode having a width of 2 mm and a total thickness of 0.23 μm was formed so as to intersect the ITO electrode by vapor-depositing Ca to a thickness of 0.08 μm and Al to a thickness of 0.15 μm. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

(Comparative Example 1)
An organic electroluminescent device was produced in the same manner as in Example 1 except that the compound represented by the following structural formula (VI) was used instead of the exemplified compound (3) used in Example 1 above.

(Comparative Example 2)
2 parts by mass of polyvinyl carbazole (PVK) as a charge transporting polymer, 0.1 part by mass of the exemplary compound (IV-1) as a light emitting material, and 1 part by mass of the compound (IV-9) as an electron transporting material are mixed. A 10% by mass dichloroethane solution was prepared and filtered through a 0.1 μm PTFE filter. Using this solution, a hole transport layer having a film thickness of 0.15 μm was formed on a glass substrate formed by etching a 2 mm wide strip-shaped ITO electrode by dipping. After sufficiently drying, a Mg—Ag alloy was vapor-deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

The organic electroluminescence device produced as described above was measured for light emission by applying a DC voltage in vacuum (133.3 × 10 ⁻³ Pa) with the ITO electrode side plus and the Mg-Ag back electrode minus. The maximum luminance and the emission color at this time were evaluated. The results are shown in Table 124. In addition, the emission lifetime of the organic electroluminescent element was measured in dry nitrogen. In the evaluation of the light emission lifetime, the current value was set so that the initial luminance was 100 cd / m ^2, and the time until the luminance was reduced by half from the initial value by constant current driving was defined as the element lifetime. The driving current density at this time is shown in Table 124 together with the element lifetime.

  From Table 124, it can be seen that by using the charge transporting polyester according to the present invention, thermal durability, high luminance and high efficiency can be realized, and the device life can be extended.

It is the schematic block diagram which showed an example of the laminated constitution of the organic electroluminescent element of this invention. It is the schematic block diagram which showed an example of the laminated constitution of the organic electroluminescent element of this invention. It is the schematic block diagram which showed an example of the laminated constitution of the organic electroluminescent element of this invention. It is the schematic block diagram which showed an example of the laminated constitution of the organic electroluminescent element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent insulator board | substrate 2 Transparent electrode 3 Hole transport layer 4 Light emitting layer 5 Electron transport layer 6 Light emitting layer 7 with a charge transport function Back electrode

Claims (8)

An organic electroluminescent device comprising a pair of electrodes consisting of an anode and a cathode, at least one of which is transparent or translucent, and one or a plurality of organic compound layers sandwiched between the pair of electrodes,
At least one of the organic compound layers has the following general formulas (I-1) and (I-2)
An organic electroluminescent device comprising at least one charge transporting polyester comprising a repeating unit containing at least one selected from the structure represented by the above as a partial structure.

(In the general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings. Represents a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, and in the general formula (I-1), k is 0 Or i represents 0, j represents 1, and in the general formula (I-2), k represents 0, i represents 1, j represents 1 , and T represents 1 carbon. Represents a divalent straight chain hydrocarbon group of ˜6 or a divalent branched hydrocarbon group of 2 to 10 carbon atoms, Ar is represented by the following general formula (II ) in the case of general formula (I-1): -1) or (II-2), and in the case of general formula (I-2), it represents a substituent represented by the following general formula (II-1) .

(In the general formula (II-1) or (II-2), Ar ₁ represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic carbon having 2 to 10 aromatic rings. Represents hydrogen, a substituted or unsubstituted divalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted divalent aromatic heterocyclic ring, and R ₁ and R ₂ each independently represent a hydrogen atom, Represents an alkyl group, a cyano group, a halogen atom, a substituted amino group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group, wherein each R ₂ in the general formulas (II-1) and (II-2) is all It may be a hydrogen atom or a combination of a hydrogen atom and another substituent, q is 0, and when Ar in the general formula (I-1) is a substituent represented by the general formula (II-1) r is 0 or 1, and Ar in the general formula (I-1) is represented by the general formula (II- In the case of the substituent represented by 2), r represents 0, and in the case of the general formula (I-2), r represents 0 .   The organic compound layer comprises at least a light emitting layer, an electron transport layer and / or an electron injection layer, and the light emitting layer contains at least one kind of the charge transporting polyester. The organic electroluminescent element as described.   The organic compound layer includes at least a light emitting layer, a hole transport layer and / or a hole injection layer, and the light emitting layer contains at least one kind of the charge transporting polyester. 2. The organic electroluminescent element according to 1.   The organic compound layer comprises at least a light emitting layer, a hole transport layer and / or a hole injection layer, an electron transport layer and / or an electron injection layer, and the light emitting layer comprises the charge transporting polyester. The organic electroluminescent element according to claim 1, comprising at least one kind.   The organic compound layer according to claim 1, wherein the organic compound layer includes only a light emitting layer having a charge transporting function, and the light emitting layer having the charge transporting function contains at least one kind of the charge transporting polyester. Electroluminescent device. The organic electroluminescent device according to claim 1, wherein the charge transporting polyester is a polyester represented by the following general formula (III-1 ) .

(In the general formula _(III-1), A 1 represents at least one selected from structures represented by the general formula (I-1) and (I-2), the divalent Y ₁ are each independently an organic Represents a group, m represents 1, and p represents an integer of 5 to 5000.) It is a manufacturing method of the organic electroluminescent element of any one of Claims 1 thru | or 6, Comprising:
The manufacturing method of the organic electroluminescent element which has an application | coating process which apply | coats the coating liquid for organic compound layers which dissolved the structural component of the said organic compound layer in the solvent by the inkjet method.   7. An image display medium comprising the organic electroluminescent elements according to claim 1 arranged in a matrix and / or segments.