JP2005235645A - Organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL element having sufficient luminance, having excellent stability and durability, allowing its area to be increased, and easy to manufacture. <P>SOLUTION: This organic electroluminescent element is composed of one or more organic compound layers sandwiched between a pair of electrodes at least one of which is transparent or translucent. In the organic electroluminescent element, at least one of the organic compound layers contains one or more kinds of charge transporting polyether comprising a repeating unit including at least one kind selected from structures shown by general formulas I-1 and I-2 as a partial structure; and at least one of the organic compound layers contains a luminescent polymer emitting light by transition from an excitation triplet state of electron energy level to a base state thereof or by transition to the base state via the excitation triplet state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an organic electroluminescent device (hereinafter referred to as “organic EL device”), and more particularly to an organic electroluminescent device using a specific charge transporting polymer.

  An electroluminescent element (hereinafter referred to as an “EL element”) is a self-luminous all-solid-state element, and is highly visible and resistant to impacts. As the EL element, an inorganic phosphor is mainly used at present, but since an AC voltage of 200 V or more is necessary for driving, there are problems such as high manufacturing cost and insufficient luminance. doing.

  On the other hand, research on EL devices using organic compounds first started with a single crystal such as anthracene, but in the case of a single crystal, 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 (for example, see Non-Patent Document 1). However, the thin film obtained by this method still has a high driving voltage of 30 V, a low density of electrons and hole carriers in the film, and a low probability of photon generation due to carrier recombination, resulting in sufficient luminance. I couldn't.

However, in recent years, in a function-separated EL device in which thin films of a hole-transporting organic low-molecular compound and a fluorescent organic low-molecular compound having an electron-transporting capability are sequentially stacked by a vacuum deposition method, a low driving voltage of about 10V is used. A device capable of obtaining a high luminance of 1000 cd / m ² or more has been reported (see, for example, Non-Patent Document 2). Since then, research and development of stacked EL devices have been actively conducted. In these stacked EL devices, holes and electrons are made of a light-emitting layer made of a fluorescent organic compound while maintaining the carrier balance between the holes and electrons through a charge transport layer made of an organic compound having a charge-transport property from the electrode. High-luminance light emission is realized by recombination of the holes and electrons injected into the light-emitting layer and confined in the light-emitting layer.

However, this type of EL device has the following three major problems for practical use.
(1) Since the element is driven at a high current density of several mA / cm ² , a large amount of Joule heat is generated. For this reason, there are many phenomena in which hole transporting low molecular weight compounds and fluorescent organic low molecular weight compounds deposited in an amorphous state by vapor deposition gradually crystallize and finally melt, resulting in a decrease in luminance and dielectric breakdown. As a result, there is a problem that the lifetime of the element is reduced.

  (2) In manufacturing the device, a thin film having a film thickness of 0.1 μm or less is formed in a plurality of vapor deposition processes of low molecular organic compounds, so pinholes are likely to occur, and strict management is required to obtain sufficient performance. It is necessary to control the film thickness under the specified conditions. Therefore, there are problems that productivity is low and it is difficult to increase the area.

  (3) What is used in the light emitting material is light emission from an excited singlet state, that is, fluorescence. However, since the generation ratio of excitons in excited singlet state and excited triplet state generated by recombination of holes and electrons in the light emitting layer is 1: 3 from the spin statistic rule based on quantum mechanics, The upper limit of the internal quantum efficiency of light emission in the EL element is theoretically 25%.

  In order to solve the problem shown in (1) above, a stable amorphous glass state can be obtained as a hole transport material, a starburst amine or a polymer in which triphenylamine is introduced into the side chain of polyphosphazene is used. There have been reports of EL devices that have been used (for example, see Non-Patent Documents 3 and 4).

  However, since these alone have an energy barrier due to the ionization potential of the hole transport material, the hole injection property from the anode or the hole injection property to the light emitting layer cannot be satisfied. Further, in the case of the former starburst amine, it is difficult to purify due to low solubility, and it is difficult to increase the purity, and in the case of the latter polymer, a high current density cannot be obtained and sufficient. There is also a problem that the luminance is not obtained.

  Further, in order to solve the problem shown in (2), research and development of an EL element having a single-layer structure capable of shortening the process has been promoted, and a conductive polymer such as poly (p-phenylene vinylene) is used. A device in which an electron transporting material and a fluorescent dye are mixed in a hole transporting polyvinyl carbazole has been proposed (see, for example, Non-Patent Documents 5 and 6). It does not reach the stacked EL element used.

  Furthermore, it has been reported that the manufacturing method is preferably a wet coating method from the viewpoint of simplification of manufacturing, workability, large area, cost, etc., and an element can also be obtained by a casting method (for example, non-processing). (See Patent Documents 7 and 8). However, since the charge transport material has poor solubility and compatibility with solvents and resins, it is easy to crystallize, and there is a problem in production or characteristics.

  In order to solve the above problem (3), it is effective to use an excited triplet state having a high probability of exciton generation, that is, a phosphorescent material. As a phosphorescent light-emitting material, an element using a platinum complex was first proposed (for example, see Non-Patent Document 9). Further, by using an iridium complex that emits phosphorescence, an external quantum efficiency of 7.5% (external extraction efficiency) Is assumed to be 20%, the internal quantum efficiency is 37.5%), and it has been shown that it is possible to exceed the external quantum efficiency of 5%, which has been the upper limit in the past (for example, non-patent Reference 10 and Patent Document 1).

However, in actual use, it is necessary to dope a specific low molecular weight organic compound that is a host compound and use it, and the same problems as described in the above (1) and (2) as in the case of a fluorescent light emitting material are required. Have.

Thin Solid Films, Vol. 94, 171 (1982) Appl. Phys. Lett. , Vol. 51,913 (1987) Proceedings of the 40th Joint Conference on Applied Physics, 30a-SZK-14 (1993) Proceedings of the 42nd Polymer Symposium, 20J21 (1993) Nature, Vol. 357, 477 (1992) 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) Nature, Vol. 395, 151 (1998) Appl. Phys. Lett. , Vol. 75, 4 (1999) International publication 00/70655 pamphlet

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to provide an organic EL device that has sufficient luminance, is excellent in stability and durability, can be increased in area, and can be easily manufactured.

  As a result of intensive studies on charge transport materials and light-emitting materials to achieve the above object, a charge transporting polyether containing at least one selected from a specific structure as a partial structure is suitable for an organic EL device, Charge mobility, thin film forming ability, and the charge transporting polyether and the transition from the excited triplet state to the ground state of the electron energy level or to the ground state via the excited triplet state. By combining with a light-emitting polymer that emits light by transition, it has been found that not only the device has excellent durability and luminous efficiency, but also has a high productivity, and the present invention has been completed.

That is, the present invention
<1> In an organic electroluminescent device composed of one or a plurality of organic compound layers sandwiched between a pair of electrodes, at least one of which is transparent or translucent,
A charge transporting polyether comprising at least one organic compound layer 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: 1 or more types, and at least one of the organic compound layers is transitioned from the excited triplet state of the electron energy level to the ground state or to the ground state via the excited triplet state. It is an organic electroluminescent element characterized by containing the luminescent polymer which light-emits by.

  In the general formulas (I-1) and (I-2), Ar represents a substituted or unsubstituted monovalent aromatic group, and X represents a substituted or unsubstituted divalent aromatic group. T represents a divalent linear hydrocarbon having 1 to 6 carbon atoms or a branched hydrocarbon having 2 to 10 carbon atoms, and k and l represent 0 or 1.

<2> The organic compound layer includes at least a light emitting layer and an electron transport layer, and at least one of the light emitting layer and the electron transport layer is represented by the general formulas (I-1) and (I-2). Containing at least one charge transporting polyether comprising a repeating unit containing at least one selected from the structure as a partial structure, wherein the light emitting layer is formed by transition from an excited triplet state of an electron energy level to a ground state. Alternatively, the organic electroluminescent element according to <1>, which contains one or more luminescent polymers that emit light upon transition to a ground state via an excited triplet state.

<3> The organic electroluminescent element according to <2>, wherein the light emitting layer contains a charge transporting material.

<4> The organic compound layer includes at least a hole transport layer, a light-emitting layer, and an electron transport layer, and at least one of the hole transport layer and the electron transport layer is represented by the general formulas (I-1) and (I- 2) containing one or more charge-transporting polyethers composed of repeating units containing at least one selected from the structure shown in 2) as a partial structure, wherein the light-emitting layer is grounded from an excited triplet state of an electron energy level. <1> Organic electroluminescence according to <1>, comprising at least one luminescent polymer that emits light upon transition to a state or upon transition to a ground state via an excited triplet state It is an element.

<5> The organic electroluminescent element as described in <4>, wherein the light emitting layer contains a charge transporting material.

<6> The organic compound layer includes at least a hole transport layer and a light-emitting layer, and at least one of the hole transport layer and the light-emitting layer is represented by the general formulas (I-1) and (I-2). Containing at least one charge transporting polyether comprising a repeating unit containing at least one selected from the structure as a partial structure, wherein the light emitting layer is formed by transition from an excited triplet state of an electron energy level to a ground state. Alternatively, the organic electroluminescent element according to <1>, which contains one or more luminescent polymers that emit light upon transition to a ground state via an excited triplet state.

<7> The organic electroluminescent element according to <6>, wherein the light emitting layer contains a charge transporting material.

<8> The organic compound layer is composed of a light emitting layer having at least a charge transporting ability, and the light emitting layer is at least one selected from the structures represented by the general formulas (I-1) and (I-2). Containing at least one charge transporting polyether comprising a repeating unit containing a species as a partial structure, and the light emitting layer is formed by a transition from an excited triplet state of an electron energy level to a ground state, or an excited triplet <1> The organic electroluminescence device according to <1>, wherein the organic electroluminescence device comprises at least one luminescent polymer that emits light upon transition to a ground state via a state.

<9> The organic electroluminescent element according to <8>, wherein the light emitting layer contains a charge transporting material.

<10> A charge transporting polyether comprising a repeating unit containing, as a partial structure, at least one selected from the structures represented by the general formulas (I-1) and (I-2) is represented by the following general formula (II): <1> The organic electroluminescence device according to <1>, which is a charge transporting polyether represented by the formula:

  In the general formula (II), A represents at least one selected from the structures represented by the general formulas (I-1) and (I-2), and R represents a hydrogen atom, an alkyl group, substituted or unsubstituted. An aryl group, or a substituted or unsubstituted aralkyl group, and p represents an integer of 5 to 5,000.

  ADVANTAGE OF THE INVENTION According to this invention, it has sufficient brightness | luminance, it is excellent in stability and durability, and the organic EL element which can be enlarged and can be manufactured easily can be provided.

Hereinafter, the present invention will be described in detail.
The organic EL device of the present invention is an organic electroluminescent device composed of one or more organic compound layers sandwiched between a pair of electrodes, at least one of which is transparent or translucent. 1 layer contains 1 or more types of charge transport polyether which consists of a repeating unit which contains at least 1 sort (s) selected from the structure shown by the following general formula (I-1) and (I-2) as a partial structure, Further, the light emitting polymer in which at least one of the organic compound layers emits light by transition from an excited triplet state of an electronic energy level to a ground state or a transition from a ground state via an excited triplet state. It is characterized by containing.

  The organic EL device of the present invention has a layer containing the charge-transporting polyether and the light-emitting polymer, and thus has sufficient luminance and is excellent in stability and durability. Further, by using the charge transporting polyether and the light emitting polymer, the area can be increased and the production can be easily performed. In particular, in the present invention, not only the charge transport layer but also the light emitting layer can be formed by a wet coating method, so that the manufacturing process can be greatly simplified as compared with the conventional device as described above.

  In the general formulas (I-1) and (I-2), Ar represents a substituted or unsubstituted monovalent aromatic group, and X represents a substituted or unsubstituted divalent aromatic group. T represents a divalent linear hydrocarbon having 1 to 6 carbon atoms or a branched hydrocarbon having 2 to 10 carbon atoms, and k and l represent 0 or 1.

  Ar represents a substituted or unsubstituted monovalent aromatic group. Specifically, a substituted or unsubstituted phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic hydrocarbon having 2 to 10 aromatics, or a substituted or unsubstituted monovalent aromatic hydrocarbon having 2 to 10 aromatics Or a substituted or unsubstituted monovalent aromatic heterocyclic ring, or a substituted or unsubstituted monovalent aromatic group containing at least one aromatic heterocyclic ring.

  The number of aromatic rings constituting the polynuclear aromatic hydrocarbon and the condensed ring aromatic hydrocarbon is not particularly limited, but those having 2 to 5 aromatic rings are preferable. In the condensed ring aromatic hydrocarbon, all condensed rings Aromatic hydrocarbons are preferred. In the present invention, the polynuclear aromatic hydrocarbon and the condensed ring aromatic hydrocarbon specifically mean a polycyclic aromatic as defined below.

  That is, the “polynuclear aromatic hydrocarbon” is a hydrocarbon in which two or more aromatic rings composed of carbon and hydrogen are present, and these aromatic rings are bonded by a carbon-carbon single bond. Represents a compound. Specific examples include biphenyl and terphenyl.

  The “fused ring aromatic hydrocarbon” means that there are two or more aromatic rings composed of carbon and hydrogen, and these aromatic rings share a pair of adjacent bonded carbon atoms. Represents a hydrocarbon compound. Specific examples include naphthalene, anthracene, phenanthrene, fluorene and the like.

  In the general formulas (I-1) and (I-2), the aromatic heterocycle selected as one of the structures represented by Ar represents an aromatic ring including elements other than carbon and hydrogen. The number of atoms (Nr) constituting the ring skeleton is preferably 5 and / or 6. In addition, the type and number of elements (heterogeneous elements) other than carbon constituting the ring skeleton are not particularly limited. For example, S, N, O, and the like are preferably used. Or two or more different atoms may be contained.

  In particular, as a heterocyclic ring having a 5-membered ring structure, thiophene, thiofin and furan, or a heterocyclic ring obtained by further substituting the 3- and 4-position carbons with nitrogen, pyrrole, or the 3- and 4-position carbons thereof. Further, a heterocyclic ring substituted with nitrogen is preferably used, and pyridine is preferably used as the heterocyclic ring having a 6-membered ring structure.

  Further, in the general formulas (I-1) and (I-2), an aromatic group containing an aromatic heterocycle selected as one of the structures represented by Ar is in an atomic group constituting the skeleton, It represents a linking group containing at least one aromatic heterocycle. These may be either all composed of a conjugated system or partially composed of a non-conjugated system, but all are composed of a conjugated system in terms of charge transportability and luminous efficiency. preferable.

  In addition, as a substituent of a benzene ring, polynuclear aromatic hydrocarbon, condensed ring aromatic hydrocarbon or heterocyclic ring selected as a structure represented by Ar, a hydrogen atom, an alkyl group, an alkoxy group, a phenoxy group, an aryl group Aralkyl group, substituted amino group, halogen atom and the like.

  As said 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 said alkoxyl 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 said aryl group, a C6-C20 thing is preferable, For example, a phenyl group, a toluyl group, etc. are mentioned. As said aralkyl group, a C7-C20 thing is preferable, For example, a benzyl group, a phenethyl group, etc. are mentioned.
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 general formulas (I-1) and (I-2), X represents a substituted or unsubstituted divalent aromatic group. Specifically, a substituted or unsubstituted phenylene group, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatics, or a substituted or unsubstituted divalent aromatic hydrocarbon having 2 to 10 aromatics A condensed ring aromatic hydrocarbon, a substituted or unsubstituted divalent aromatic heterocyclic ring, or a substituted or unsubstituted divalent aromatic group containing at least one aromatic heterocyclic ring.
Here, the “polynuclear aromatic hydrocarbon”, “fused ring aromatic hydrocarbon”, “aromatic heterocycle” and “aromatic group containing an aromatic heterocycle” are as described above.

  In general formulas (I-1) and (I-2), k and l represent 0 or 1, and T represents a divalent linear hydrocarbon having 1 to 6 carbon atoms, or 2 having 2 to 10 carbon atoms. A divalent branched hydrocarbon group, preferably selected from a divalent straight chain hydrocarbon group having 2 to 6 carbon atoms and a divalent branched chain hydrocarbon group having 3 to 7 carbon atoms. The

  Specific examples of the T include the following.

  As a hole transporting polyether (charge transporting polyether) 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, Those represented by the formula (II) are preferably used.

  In general formula (II), A represents at least one selected from the structures represented by general formulas (I-1) and (I-2), and two or more types of A are present in one polymer. May be included.

  In general formula (II), R represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. As said 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 said aryl group, a C6-C20 thing is preferable, For example, a phenyl group, a toluyl group, etc. are mentioned. As said aralkyl group, a C7-C20 thing is preferable, For example, a benzyl group, a phenethyl group, etc. are mentioned. Examples of the substituent for the substituted aryl group and the substituted aralkyl group include a hydrogen atom, an alkyl group, an alkoxy group, a substituted amino group, and a halogen atom.

  In general formula (II), p representing the degree of polymerization is in the range of 5 to 5000, preferably 10 to 1000. The weight average molecular weight Mw of the charge transporting polyether of the present invention is preferably in the range of 5,000 to 1,000,000, more preferably in the range of 10,000 to 300,000. .

  The charge transporting polyether of the present invention is a hole transporting monomer (charge transporting monomer) represented by the following structural formula (III-1) or (III-2), for example, 4th edition Experimental Chemistry Course Vol. 28. (Maruzen, 1993) and the like can be synthesized by polymerization by a known method. In Structural Formula (III-1) or (III-2), Ar, X, T, k, and l are Ar, X, T, k in General Formula (I-1) or (I-2), respectively. , L, respectively.

Specifically, the hole transporting polyether represented by the general formula (II) can be synthesized, for example, as follows.
(1) The charge transporting polyether in the present invention is a charge transporting compound having two hydroxyalkyl groups among the compounds represented by the general formulas (III-1) and (III-2) (charges). The transportable monomer can be synthesized by a method of heat dehydration condensation.

  In this case, it is desirable that the charge transporting monomer is heated and melted without solvent to promote the polymerization reaction due to the elimination of water, and the monomer is heated and melted to react under reduced pressure in order to promote the polymerization reaction due to the elimination of water. . When a solvent is used, a solvent azeotroped with water, for example, trichloroethane, toluene, chlorobenzene, dichlorobenzene, nitrobenzene, 1-chloronaphthalene, etc. is effective for removing water, and charge transporting monomer 1 Preferably it is used in the range of 1 to 100 equivalents, more preferably in the range of 2 to 50 equivalents, relative to equivalents. 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. If the polymerization does not proceed, the solvent may be removed from the reaction system and heated and stirred in a viscous state.

  (2) In addition, the charge transporting polyether is obtained by dehydration condensation using a protonic acid such as p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, trifluoroacetic acid, or a Lewis acid such as zinc chloride as an acid catalyst. It can also be synthesized. In this case, the acid catalyst is preferably used in the range of 1/10000 to 1/10 equivalent, more preferably in the range of 1/1000 to 1/50 equivalent, relative to 1 equivalent of the charge transporting monomer.

  In order to remove water generated during the polymerization, it is preferable to use a solvent azeotropic with water. As the solvent, toluene, chlorobenzene, dichlorobenzene, nitrobenzene, 1-chloronaphthalene and the like are effective, and preferably 1 to 100 equivalents, more preferably 2 to 50 equivalents with respect to 1 equivalent of the charge transporting monomer. Used in a range. 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.

  (3) Further, the above charge transporting polyether includes an isocyanic alkyl such as cyclohexyl cyanide, a cyanate such as p-tolyl cyanate and 2,2-bis (4-cyanatophenyl) propane, and dichlorocarbodiimide. It can also be synthesized by a method using a condensing agent such as (DCC) or trichloroacetonitrile.

  In this case, the condensing agent is preferably used in the range of 1/2 to 10 equivalents, more preferably in the range of 1 to 3 equivalents, relative to 1 equivalent of the charge transporting monomer. As the solvent, toluene, chlorobenzene, dichlorobenzene, 1-chloronaphthalene and the like are effective, and preferably in the range of 1 to 100 equivalents, more preferably in the range of 2 to 50 equivalents with respect to 1 equivalent of the charge transporting monomer. Used. Although reaction temperature can be set arbitrarily, it is preferable to make it react from the room temperature to the boiling point of a solvent.

  Of the synthesis methods (1), (2) and (3), the synthesis method (1) or (3) is preferred because isomerization and side reactions are unlikely to occur. In particular, the synthesis method (3) is more preferable because the reaction conditions are milder.

  When the solvent is not used after completion of the reaction, the reaction product is dissolved in a soluble solvent. When a solvent is used, the reaction product is dropped as it is into a poor solvent in which a charge transporting polymer such as methanol or ethanol or a charge transporting polymer such as acetone is difficult to dissolve, to precipitate a charge transporting polyether, After separating the transportable ether, it is thoroughly washed with water or an organic solvent and dried. Furthermore, if necessary, the reprecipitation treatment may be repeated in which it is dissolved in a suitable organic solvent and dropped into a poor solvent to precipitate the charge transporting polymer. The reprecipitation treatment is preferably carried out with efficient stirring using a mechanical stirrer or the like.

  The solvent for dissolving the charge transporting polyether in the reprecipitation treatment is preferably used in the range of 1 to 100 equivalents, more preferably 2 to 50 equivalents, per 1 equivalent of the charge transporting polyether. The poor solvent is preferably used in an amount of 1 to 1000 equivalents, more preferably 10 to 500 equivalents, per 1 equivalent of the charge transporting polyether. Furthermore, in the above reaction, a copolymer can be synthesized by using two or more charge transporting monomers, preferably in the range of 2 to 5, more preferably in the range of 2 to 3. By copolymerizing different kinds of charge transporting monomers, it is possible to control electrical characteristics, film formability, and solubility.

  If the polymerization degree p of the charge transporting polyether is too low, the film formability is inferior and a strong film is difficult to obtain. If it is too high, the solubility in the solvent is lowered and the workability is deteriorated. Although it is set in the range of 5000, it is preferably in the range of 10 to 3000, more preferably in the range of 15 to 1000.

  The terminal group of the charge transporting polyether may be a hydroxyl group as in the case of the charge transporting monomer, that is, R in the general formula (II) may be a hydrogen atom, but the polymer physical properties such as solubility, film-forming property, mobility, etc. In the case of influence, the end group R can be modified to control physical properties. For example, the terminal hydroxyl group can be alkyl etherified with alkyl sulfate, alkyl iodide or the like.

  The specific reagent can be arbitrarily selected from dimethyl sulfate, diethyl sulfate, methyl iodide, ethyl iodide and the like, and is preferably in the range of 1 to 3 equivalents, more preferably 1 to 3 equivalents with respect to the amount of terminal hydroxyl groups. Used in the range of 2 equivalents. In this case, a base catalyst can be used, and the base catalyst can be arbitrarily selected from sodium hydroxide, potassium hydroxide, sodium hydride, sodium metal and the like, and preferably 1 for the amount of terminal hydroxyl groups. It is used in the range of -3 equivalents, more preferably in the range of 1-2 equivalents. The reaction temperature can be in the range of 0 ° C. to the boiling point of the solvent used.

  In addition, the solvent used in this case is selected from inert solvents such as benzene, toluene, methylene chloride, tetrahydrofuran, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone. A single solvent or a mixed solvent of 2 to 3 kinds thereof can be used. Depending on the reaction, a quaternary ammonium salt such as tetra-n-butylammonium iodide can be used as a phase transfer catalyst.

Further, R in the general formula (II) can be converted to an acyl group by acylating the terminal hydroxyl group with an acid halide. The acid halide is not particularly limited, and examples thereof include acryloyl chloride, crotonoyl chloride, methacryloyl chloride, n-butyl chloride, 2-furoyl chloride, benzoyl chloride, cyclohexanecarbonyl chloride, enanthyl chloride, phenylacetyl chloride, o -Toluoyl chloride, m-toluoyl chloride, p-toluoyl chloride and the like The acid halide is preferably in the range of 1 to 3 equivalents, more preferably 1 to 2 equivalents, relative to the amount of terminal hydroxyl groups. Use in a range.

  In this case, a base catalyst can be used, and the base catalyst can be arbitrarily selected from pyridine, dimethylaminopyridine, trimethylamine, triethylamine and the like, and is preferably in the range of 1 to 3 equivalents relative to the acid chloride. Is used in the range of 1 to 2 equivalents.

  Examples of the solvent used include benzene, toluene, methyl chloride, tetrahydrofuran, and methyl ethyl ketone. The reaction can be carried out in the range of 0 ° C. to the boiling point of the solvent, but preferably in the range of 0 ° C. to 30 ° C.

  Furthermore, acylation can also be performed using an acid anhydride such as acetic anhydride. When a solvent is used in this reaction, specifically, an inert solvent such as benzene, toluene, chlorobenzene or the like can be used. The reaction can be carried out in the range of 0 ° C. to the boiling point of the solvent, but preferably in the range of 50 ° C. to the boiling point of the solvent.

  In addition, a urethane residue (—CONH—R ′) can be introduced into the terminal of the charge transporting polyether using monoisocyanate. Specific monoisocyanates include isocyanic acid benzyl ester, isocyanic acid n-butyl ester, isocyanic acid t-butyl ester, isocyanic acid cyclohexyl ester, isocyanic acid 2,6-dimethyl ester, isocyanic acid ethyl ester, isocyanic acid isopropyl ester. Isocyanic acid 2-methoxyphenyl ester, isocyanic acid 4-methoxyphenyl ester, isocyanic acid n-octadecyl ester, isocyanic acid phenyl ester, isocyanic acid i-propyl ester, isocyanic acid m-tolyl ester, isocyanic acid p-tolyl ester, It can be arbitrarily selected from isocyanic acid 1-naphthyl ester and the like. The amount used is preferably in the range of 1 to 3 equivalents, more preferably in the range of 1 to 2 equivalents, relative to the amount of terminal hydroxyl groups.

  Examples of solvents used in this case include benzene, toluene, chlorobenzene, dichlorobenzene, methylene chloride, tetrahydrofuran, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. Can do.

  The reaction temperature can be from 0 ° C. to the boiling point of the solvent used. If the reaction is difficult to proceed, add a metal compound such as dibutyltin (II) dilaurate, tin (II) octylate or lead naphthenate, or a tertiary amine such as triethylamine, trimethylamine, pyridine or dimethylaminopyridine as a catalyst. You can also.

Next, the luminescent polymer in the present invention will be described.
The light-emitting polymer in the present invention includes a compound that emits light by transition from an excited triplet state to a ground state of an electronic energy level in a solid state or by transition to a ground state via an excited triplet state. Is used.

  Here, the light emission caused by the transition from the excited triplet state to the ground state of the electron energy level refers to light emitted by directly emitting phosphorescence from the excited triplet state, and the excitation of the electron energy level. The light emission by the transition to the ground state via the triplet state is, for example, light emission caused by transferring from the excited triplet state to another energy state and emitting phosphorescence and / or fluorescence at the transition to the ground state. Say.

  As a compound that emits light by transition to the ground state via the excited triplet state, for example, as disclosed in JP-A-2002-50483, it corresponds to a phosphorescent first organic compound. Energy transfer from the excited triplet state of the portion to the excited triplet state of the portion corresponding to the fluorescent organic second organic compound occurs, and the fluorescent light emission is generated from the second organic compound portion. Things.

  In the case where the light emitting polymer includes a portion that emits light through the excited triplet state, among the phosphorescent portion and the fluorescent portion included in the light emitting portion of the light emitting polymer. It is preferable that at least one of them forms part of the polymer chain or is bonded to the polymer chain. In this case, the phosphorescent portion and / or the fluorescent portion that forms a part of the polymer chain or is bonded to the polymer chain may form the main chain of the polymer, Moreover, a polymer side chain may be formed.

  In the above case, the light emitting polymer may be a mixture of a polymer containing a phosphorescent part and a polymer containing a fluorescent part, or may contain a phosphorescent part. It may be a copolymer of a monomer and a monomer containing a fluorescent portion.

  The value of the quantum yield of light emission including light emission from the excited triplet state in the light emitting polymer is preferably 0.1 or more, more preferably 0.3 or more, and further preferably 0.5 or more. It is. Examples of the compound having a high quantum yield of excited triplet emission that can be applied to these phosphorescent moieties include metal complexes, but are not limited thereto.

  Specific examples of the metal complex include (1) transition metal complexes such as iridium complexes and platinum complexes, and transition metal complexes such as derivatives thereof, and (2) rare earth metal complexes. These are preferable in that they have an excited triplet state that is relatively stable even at high temperatures. Further, as described later, it is also preferable from the viewpoint that complexation can be easily performed by coordinating a polymer having a functional group having coordination ability to a transition metal atom.

  As the transition metal used in the transition metal complex, in the periodic table, the first transition element series includes Sc from atomic number 21 to Zn of atomic number 30 and the second transition element series includes Y from atomic number 39 to atomic number. Up to Cd of 48, and from the Hf of atomic number 72 to Hg of atomic number 80 in the third transition element series. The rare earth metal used in the rare earth metal complex includes La of atomic number 57 to Lu of atomic number 71 in the periodic table.

  The luminescent moiety is preferably nonionic. This is because, when the luminescent portion is ionic, for example, when a voltage is applied to the luminescent layer containing the luminescent portion, electrochemiluminescence occurs, and the response speed of this luminescence becomes extremely slow, on the order of minutes, This is because it is not preferable for display applications.

  In the above-described present invention, “the luminescent portion forms part of the polymer chain” means that the luminescent partial structure constitutes at least one kind of repeating unit of the polymer chain. Therefore, when the light emitting polymer is a copolymer as described above, at least one of the constituent monomers has a light emitting partial structure. In addition, the light-emitting portion may form a polymer main chain or a side chain (such as a pendant group).

  In addition, the above-mentioned “the light-emitting moiety is bonded to the polymer chain” means that the light-emitting moiety may be bonded to the polymer compound regardless of its form. Specific methods for obtaining such a light-emitting polymer include a method of incorporating a light-emitting moiety as a main chain of the polymer, or a method of bonding as a side chain (including a pendant group). However, it is not limited to these. In the case of the transition metal complex and the rare earth metal complex, a method of incorporating at least one of the ligands forming the complex as a polymer main chain or a method of bonding as a side chain is exemplified. However, it is not limited to these.

  Examples of the ligand coordinated to the transition metal complex and rare earth metal complex include acetylacetonato, 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, and 1,10-. Examples thereof include phenanthroline, 2-phenylpyridine, porphyrin, phthalocyanine, pyrimidine, quinoline and / or derivatives thereof, but are not limited thereto. One or more kinds of these ligands are coordinated with respect to one complex. Further, as such a complex compound, a binuclear complex or a polynuclear complex, or a complex of two or more kinds of complexes can be used.

  In the light-emitting portion of the present invention, the metal atom that becomes the central metal of the metal complex is constrained at one or more sites of the polymer chain. A method for achieving this is not particularly limited, and examples thereof include complexation by coordination bond as described above, complexation by charge transfer, ionic bond, and covalent bond. Among these, a method in which a ligand is bonded to a polymer to form a complex with a light-emitting substance is preferable because a change in the electronic state of the light-emitting substance can be reduced and immobilized on the polymer. In this case, a method in which a ligand is covalently bonded to a polymer to form a complex is particularly preferable because the material can be easily designed and synthesized.

  In addition, when the metal atom serving as the central metal is an ion, it is preferable to adopt a method in which the light-emitting portion is neutral (nonionic) for the reasons described above. Examples thereof include, but are not limited to, a method of forming an organometallic compound having a covalent bond sufficient to neutralize the valence of ions with the bond.

  The light emitting polymer for constraining the metal atom in the present invention is not particularly limited. For example, a heterocyclic compound such as a pyridine group, bipyridyl group, pyrimidine group, or quinoline group exemplified as the ligand is a polymer. Those bonded to the main chain and / or the side chain can be used. More specifically, as such a polymer, a polymer containing a ligand in the main chain such as polypyridinediyl, polybipyridinediyl, polyquinolinediyl and / or a derivative thereof, polyvinylpyridine, poly (meth) acrylic Examples thereof include a polymer having a ligand in the side chain such as pyridine and polyvinylquinoline and / or a derivative thereof, and a polymer in which the above structures are combined.

  In addition, as the light-emitting polymer used in the present invention, a copolymer of a monomer unit in which a light-emitting part is part of or bonded to a monomer unit having no light-emitting part may be used. it can. Here, examples of the monomer unit having no light-emitting moiety include alkyl (meth) acrylates such as methyl acrylate and methyl methacrylate, styrene, and derivatives thereof, but are not limited thereto. is not.

  The degree of polymerization of the luminescent polymer in the present invention is preferably an integer in the range of 5 to 10,000, and more preferably an integer in the range of 10 to 5,000. Further, the weight average molecular weight Mw of the luminescent polymer is preferably in the range of 5,000 to 1,000,000, and more preferably in the range of 10,000 to 300,000.

Next, the layer structure of the organic EL element of the present invention will be described in detail.
The organic EL device of the present invention comprises a pair of electrodes, at least one of which is transparent or translucent, and one or a plurality of organic compound layers sandwiched between the electrodes, and at least one of the organic compound layers is It contains one or more kinds of the charge transporting polyether and one or more kinds of the light emitting polymer.

  That is, the organic EL device of the present invention is a device in which a light emitting layer or a plurality of organic compound layers including a light emitting layer is formed between a pair of electrodes of an anode and a cathode. An injection layer, an electron transport layer, a protective layer, and the like may be included, and each of these layers may have other functions. Various materials can be used for forming each layer, but at least one of the organic compound layers needs to contain the charge-transporting polyether resin and the light-emitting polymer.

  In the organic EL device of the present invention, when there is one organic compound layer, the organic compound layer means a light emitting layer having a carrier transporting ability, and the light emitting layer contains the charge transporting polyether and the light emitting polymer. It contains. Further, when there are a plurality of organic compound layers (in the case of function separation type), at least one of them is a light emitting layer (this light emitting layer may or may not have a carrier transporting ability). The other organic compound layer means a carrier transport layer, that is, a hole transport layer, an electron transport layer, or a hole transport layer and an electron transport layer, and at least one of these layers is the charge transport polymer. It contains ether and the light emitting layer contains the light emitting polymer.

  Specifically, for example, an organic EL device composed of at least a light emitting layer and an electron transport layer, an organic EL device composed of at least a hole transport layer, a light emitting layer and an electron transport layer, or at least a hole transport layer and a light emitting layer In the organic EL device composed of the above, at least one of these layers (the light emitting layer, the hole transport layer, and the electron transport layer) contains the charge transporting polyether, and the light emitting layer further contains at least one kind of the light emitting polymer. What is formed. In the organic EL device of the present invention, the light emitting layer may contain a charge transport material (a hole transport material other than the charge transport polyether, an electron transport material). Details will be described later.

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

  The organic EL element shown in FIG. 1 is formed by sequentially laminating a transparent electrode 2, a light emitting layer 4, an electron transport layer 5, and a back electrode 7 on a transparent insulator substrate 1. The organic EL element shown in FIG. 2 is formed by sequentially laminating a transparent electrode 2, a hole transport layer 3, a light emitting layer 4, an electron transport layer 5 and a back electrode 7 on a transparent insulator substrate 1. The organic EL element shown in FIG. 3 is formed by sequentially laminating a transparent electrode 2, a hole transport layer 3, a light emitting layer 4 and a back electrode 7 on a transparent insulator substrate 1. The organic EL element shown in FIG. 4 is formed by sequentially laminating a transparent electrode 2, a light emitting layer 6 having a carrier transporting capability, and a back electrode 7 on a transparent insulator substrate 1. In addition to these layers, a hole injection layer, an electron injection layer, and the like are provided as necessary. Each will be described in detail below.

  Depending on the structure of the organic compound layer containing the charge transporting polyether in the present invention, for example, in the case of the layer structure of the organic EL device shown in FIG. In any case, the light emitting layer has a carrier transporting ability), and in the case of the organic EL element layer configuration shown in FIG. 2, the hole transporting layer 3 and the electron transporting layer 5 Both can act, and in the case of the layer structure of the organic EL element shown in FIG. 3, both act as a hole transport layer 3 and a light emitting layer 4 (in this case, a light emitting layer having a carrier transport ability). In the case of the layer structure of the organic EL element shown in FIG. 4, it can act as the light emitting layer 6 having a carrier transporting ability.

Hereinafter, the material of the electrode and each layer and the manufacturing method will be described.
In the case of the layer structure of the organic EL 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. Further, the transparent electrode 2 is preferably transparent for taking out light emission like the transparent insulator substrate and having a high work function for injecting holes. Indium tin oxide (ITO), tin oxide (NESA) In addition, oxide films such as indium oxide and zinc oxide, and gold, platinum, palladium and the like deposited or sputtered are preferably used.

  In the case of the layer structure of the organic EL element shown in FIGS. 1 and 2, the electron transport layer 5 may be formed of the charge transporting polyether alone provided with a function (electron transport ability) according to the purpose. In order to adjust the electron mobility for the purpose of further improving the electrical characteristics, the electron transporting material other than the charge transporting polyether is used with respect to the total weight of the material constituting the electron transporting layer 5. It may be formed by mixing and dispersing in the range of 1 to 50% by weight. As such an electron transporting material, an oxadiazole derivative, a nitro-substituted fluorenone derivative, a diphenoquinone derivative, a thiopyrandioxide derivative, a fluorenylidenemethane derivative, and the like are preferable.

  Specific examples of the electron transport material include, but are not limited to, the following exemplary compounds (IV-1) to (IV-3). When the charge transporting polyether is not used, the electron transport layer 5 is formed using these electron transporting materials alone.

  For the purpose of improving the electron injection property from the cathode, the material for forming the electron injection layer between the electron transport layer 5 and the back electrode 7 has a function of injecting electrons from the cathode. Any material that is the same as the electron transport material can be used.

  In the case of the layer structure of the organic EL element shown in FIGS. 2 and 3, the hole transport layer 3 may be formed of a charge transporting polyether having a function (hole transport ability) according to the purpose. However, in order to adjust the hole mobility, a hole transport material other than the charge transporting polyether is mixed and dispersed in the range of 1 to 50% by weight with respect to the total weight of the material constituting the hole transport layer 3. It may be.

  As such a hole transport material, a tetraphenylenediamine derivative, a triphenylamine derivative, a carbazole derivative, a stilbene derivative, an aryl hydrazone derivative, a porphyrin compound, or the like is preferably used. Particularly preferred specific examples include the following exemplified compounds (V-1) to (V-6). Among these, tetraphenylenediamine derivatives are used because of their good compatibility with charge transporting polyethers. preferable. Moreover, you may use it by mixing with other general purpose resin etc. When the charge transporting polyether is not used, the hole transport layer 3 is formed by using these hole transporting materials alone.

  For the purpose of improving the hole injection property from the anode, the material for forming the hole injection layer between the transparent electrode 2 and the hole transport layer 3 has a function of injecting holes from the anode. Any material that is the same as the hole transport material can be used.

  In the case of the layer structure of the organic EL element shown in FIGS. 1, 2 and 3, the light emitting layer 4 may be formed of the light emitting polymer alone, but further improves the electrical characteristics and the light emitting characteristics, etc. For this purpose, the charge-transporting polyether may be mixed and dispersed in the light-emitting polymer in the range of 1 to 50% by weight based on the total weight of the layer. In addition, a charge transporting material other than the charge transporting polyether may be mixed and dispersed in the range of 1 to 50% by weight based on the weight of the entire layer.

  In the layer structure of the organic EL element shown in FIG. 4, when the light emitting layer is the light emitting layer 6 having a carrier transport ability, the light emitting layer 6 functions according to the purpose (hole transport ability or electron transport ability), for example. The light-emitting polymer was dispersed in the charge-transporting polyether provided with a luminescent material in an amount of 50% by weight or less with respect to the total weight of the material constituting the light-emitting layer 6 having a carrier-transporting ability. Although it is an organic compound layer, in order to adjust the balance between holes and electrons injected into the organic EL element, a charge transporting material other than the charge transporting polyether may be dispersed in a range of 10 to 50% by weight. Good.

As such a charge transporting material, when adjusting the electron mobility, the electron transporting material is preferably an oxadiazole derivative, a nitro-substituted fluorenone derivative, a diphenoquinone derivative, a thiopyrandioxide derivative, a fluorenylidenemethane derivative. As specific examples, the exemplified compounds (IV-1) to (IV-3) can be mentioned.
Moreover, it is preferable to use an organic compound that does not exhibit a strong electron interaction with the charge transporting polyether. More preferably, the following exemplified compound (VI) is used, but it is not limited thereto.

  Similarly, when adjusting the hole mobility, preferred examples of the hole transport material include tetraphenylenediamine derivatives, triphenylamine derivatives, carbazole derivatives, stilbene derivatives, arylhydrazone derivatives, porphyrin compounds, and the like. Specific examples include the exemplary compounds (V-1) to (V-6), and a tetraphenylenediamine derivative is preferable because of its good compatibility with the charge transporting polyether.

  In the case of the layer structure of the organic EL element shown in FIGS. 1 to 4, the back electrode 7 is made of a metal that can be vacuum-deposited and has a low work function for performing electron injection. , Silver, indium and alloys thereof. Further, a protective layer may be provided on the back electrode 7 in order to prevent the element from being deteriorated by 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. Resin. For forming the protective layer, a vacuum deposition method, a sputtering method, a plasma polymerization method, a CVD method, or a coating method can be applied.

  Each layer formation of the organic EL element shown in FIGS. 1 to 4 is performed as follows. First, the hole transport layer 3, the light emitting layer 4, or the light emitting layer 6 having a carrier transport ability is formed on the transparent electrode 2 according to the layer configuration of each organic EL element. The hole transport layer 3, the light emitting layer 4 and the light emitting layer 6 having carrier transporting capability are obtained by dissolving or dispersing each of the above materials in a vacuum deposition method or an organic solvent, and using the obtained coating solution on the transparent electrode 2. The film is formed by using a spin coating method, a dip method or the like.

Next, according to the layer configuration of each organic EL element, the light emitting layer 4 and the electron transport layer 5 are prepared by dissolving or dispersing the above materials in a vacuum deposition method or an organic solvent, and using the obtained coating liquid. The hole transport layer 3 and the light emitting layer 4 are formed by forming a film using a spin coating method, a dip method or the like.
In the present invention, since a polymer is included as a charge transport material and a light emitting material, each layer is preferably formed by a film forming method using a coating solution.

  The film thicknesses of the hole transport layer 3, the light emitting layer 4 and the electron transport layer 5 to be formed are each preferably 0.1 μm or less, and particularly preferably in the range of 0.03 to 0.08 μm. Further, the thickness of the light emitting layer 6 having carrier transporting ability is preferably in the range of 0.03 to 0.2 μm. In addition, it is preferable that the film thickness in the case of forming the said hole injection layer and an electron injection layer is a film thickness comparable as the said hole transport layer 3 and the electron transport layer 5, respectively, or a thin film thickness.

  The dispersion state of each material (the charge transporting polyether, the light emitting material, etc.) in the layer may be a molecular dispersion state or a fine particle dispersion state. In the case of a film forming method using a coating solution, it is necessary to use a common solvent for each material as a dispersion solvent in order to obtain a molecular dispersion state. It is necessary to select it in consideration of the dispersibility and solubility. In order to disperse into fine particles, a ball mill, a sand mill, a paint shaker, an attritor, a ball mill, a homogenizer, an ultrasonic method, or the like can be used.

  Finally, the back electrode 7 is formed on the electron transport layer 5, the light emitting layer 4, or the light emitting layer 6 having carrier transporting capability by a vacuum deposition method, thereby completing the device.

The organic EL device of the present invention can emit light sufficiently by applying a DC voltage between a pair of electrodes, for example, at 4 to 20 V and a current density in the range of 1 to 200 mA / cm ² .

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not restrict | limited to these Examples.
(Example 1)
1 part by weight of charge transporting polyether (the following exemplified compound (VII-2), Mw: 6.13 × 10 ⁴ ) as a charge transporting material and phosphorescent host material, and the following exemplified compound (VIII) as a phosphorescent polymer Was mixed with 0.1 part by weight to prepare a 10% by weight dichloroethane solution and filtered through a 0.1 μm PTFE filter. Using this solution, a 2 mm wide strip-shaped ITO electrode, which has been washed and dried, is applied by spin coating to a light emitting layer having a thickness of 0.15 μm and a charge transporting capability. Formed.

After sufficiently drying, a charge transporting polyether (the following exemplified compound (VII-3), Mw: 1.08 × 10 ⁵ ) was prepared as an electron transporting material as a 5 wt% dichloroethane solution, and 0.1 μm PTFE was prepared. After filtering with a filter, this solution was applied onto the light emitting layer by a spin coating method to form an electron transport layer having a thickness of 0.1 μm. Finally, 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 intersect the ITO electrode. The effective area of the produced organic EL element was 0.04 cm ² .

The organic EL device produced as described above was measured for light emission by applying a DC voltage of 11 V in vacuum (1.33 × 10 ⁻¹ Pa) with the ITO electrode side plus and the Mg—Ag back electrode minus. The maximum brightness and emission color at this time were evaluated. The results are shown in Table 1. Moreover, the light emission lifetime of the organic EL 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 50 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 drive current density at this time is shown in Table 1 together with the element lifetime.

(Example 2)
A charge transporting polyether (the following exemplified compound (VII-1), Mw: 7.24 × 10 ⁴ ) was prepared as a 5 wt% chlorobenzene solution as a hole transporting material, and filtered through a 0.1 μm PTFE filter. Using this solution, a hole-transporting layer having a thickness of 0.1 μm was formed on a glass substrate formed by etching a 2 mm-wide strip-shaped ITO electrode that had been washed and dried, by spin coating.

After sufficiently drying, 1 part by weight of a charge transporting polyether (the following exemplified compound (VII-2) (Mw: 6.13 × 10 ⁴ )) as a charge transporting material and phosphorescent host material, and a phosphorescent polymer The following exemplified compound (VIII) is mixed with 0.1 part by weight, prepared as a 10 wt% dichloroethane solution, filtered through a 0.1 μm PTFE filter, and this solution is applied onto the hole transport layer by spin coating. A light emitting layer having a thickness of 0.15 μm and having a charge transporting capability was formed.

After sufficiently drying, a charge transporting polyether (the following exemplified compound (VII-3) as an electron transporting material was prepared as a 5 wt% dichloroethane solution, filtered through a 0.1 μm PTFE filter, An electron transport layer having a film thickness of 0.1 μm was formed on the light emitting layer by spin coating, and finally 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. The organic EL device was formed to intersect with the ITO electrode, and the effective area of the produced organic EL device was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

(Example 3)
A charge transporting polyether (the following exemplified compound (VII-1), Mw: 7.24 × 10 ⁴ ) was prepared as a 5 wt% chlorobenzene solution as a hole transporting material, and filtered through a 0.1 μm PTFE filter. Using this solution, a hole-transporting layer having a thickness of 0.1 μm was formed on a glass substrate formed by etching a 2 mm-wide strip-shaped ITO electrode that had been washed and dried, by spin coating.

After sufficiently drying, 1 part by weight of the charge transporting polyether of Synthesis Example 2 (the following exemplified compound (VII-2), Mw: 6.13 × 10 ⁴ ) as a charge transporting material / phosphorescent host material and phosphorescence emission 0.1 parts by weight of the following exemplified compound (VIII) as a conductive polymer is mixed to prepare a 10 wt% dichloroethane solution, which is filtered through a 0.1 μm PTFE filter, and this solution is spin-coated on the hole transport layer. Was applied to form a light emitting layer having a charge transporting ability of 0.15 μm. Finally, 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 intersect the ITO electrode. The effective area of the produced organic EL element was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

Example 4
0.5 parts by weight of a charge transporting polyether (the following exemplified compound (VII-1), Mw: 7.24 × 10 ⁴ ) as a charge transporting material, and a charge transporting polyether (as a charge transporting material and a phosphorescent host material) 0.5 parts by weight of the following exemplary compound (VII-2), Mw: 6.13 × 10 ⁴ ), and 0.1 part by weight of the following exemplary compound (VIII) as a phosphorescent polymer are mixed. Prepared as a weight% dichloroethane solution and filtered through a 0.1 μm PTFE filter. Using this solution, a 2 mm wide strip-shaped ITO electrode, which has been washed and dried, is applied by spin coating to a glass substrate formed by etching to form a light-emitting layer having a thickness of 0.15 μm and having a charge transporting ability. Formed. Finally, 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 produced organic EL element was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

(Example 5)
In Example 3, before forming the hole transport layer, on the glass substrate on which the strip-shaped ITO electrode was formed, Baytron P (manufactured by Bayer Co., Ltd., polyethylene dioxide thiophene (exemplary compound IX below) and polystyrene sulfonic acid were used. A polymer mixed water dispersion) was applied by spin coating, and a hole injection layer having a thickness of 0.05 μm was formed between the ITO electrode and the hole transport layer. The device was created.

(Comparative Example 1)
Using the following exemplified compound (X) as a phosphorescent host material and the following exemplified compound (XI) as a phosphorescent material, co-evaporation is performed on a glass substrate formed by etching a 2 mm wide strip-shaped ITO electrode that has been washed and dried. Was deposited so that the amount of the compound (XI) in the film was 5% by weight with respect to the weight of the compound in the whole film to form a light emitting layer having a film thickness of 0.065 μm. Next, an electron transport layer having a thickness of 0.05 μm was formed on the light-emitting layer by vacuum deposition using the exemplified compound (IV-1) as an electron transport material. Finally, 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 produced organic EL element was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

(Comparative Example 2)
Hole transport with a thickness of 0.05 μm by vacuum deposition using the above exemplified compound (V-2) as a hole transport material on a glass substrate formed by etching a 2 mm wide strip-shaped ITO electrode that has been dried after washing. A layer was formed. Further, on the hole transport layer, the exemplary compound (X) as the phosphorescent host material and the exemplary compound (XI) as the phosphorescent material are used, and the amount of the compound (XI) in the film is reduced by co-evaporation. The light emitting layer having a film thickness of 0.065 μm was formed by vapor deposition so as to be 5% by weight with respect to the weight of the above compound. Next, an electron transport layer having a thickness of 0.05 μm was formed on the light emitting layer by vacuum deposition using the exemplified compound (IV-1) as an electron transport material. Finally, 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 produced organic EL element was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

(Comparative Example 3)
Hole transport with a thickness of 0.05 μm by vacuum deposition using the above exemplified compound (V-2) as a hole transport material on a glass substrate formed by etching a 2 mm wide strip-shaped ITO electrode that has been dried after washing. A layer was formed. Further, on the hole transport layer, the exemplary compound (X) as the phosphorescent host material and the exemplary compound (XI) as the phosphorescent material are used, and the amount of the compound (XI) in the film is reduced by co-evaporation. The light emitting layer having a film thickness of 0.065 μm was formed by vapor deposition so as to be 5% by weight with respect to the weight of the above compound. Finally, 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 produced organic EL element was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

(Comparative Example 4)
1 part by weight of the exemplified compound (V-6) as a charge transport material, 0.5 part by weight of the exemplified compound (X) as a phosphorescent host material, and 0.05 part by weight of the exemplified compound (XI) as a phosphorescent material. Were mixed to prepare a 5% by weight dichloroethane solution, and filtered through a 0.1 μm PTFE filter. Using this solution, a 2 mm wide strip-shaped ITO electrode, which has been washed and dried, is applied by spin coating to a light emitting layer having a thickness of 0.15 μm and a charge transporting capability. Formed. Thereafter, 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 produced organic EL element was 0.04 cm ² .
Evaluation similar to Example 1 was performed about the said organic EL element. The results are shown in Table 1.

  As shown in the above examples, the charge transporting polyether comprising a repeating structural unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure is: It has an ionization potential and charge mobility suitable for an organic EL element, and it was possible to form a good thin film using a spin coating method, a dip method, or the like. In addition, a sufficiently high luminance can be obtained by using a light-emitting polymer that emits light by transition from the excited triplet state to the ground state of the electron energy level or from the ground state via the excited triplet state. Indicated. Furthermore, in the present invention, since the light emitting polymer is used also as the light emitting layer, the entire device can be easily manufactured, and the obtained organic EL device has few defects such as pinholes and can be easily increased in area. Moreover, it had excellent durability and light emission characteristics.

It is typical sectional drawing which shows an example of the organic EL element of this invention. It is typical sectional drawing which shows another example of the organic EL element of this invention. It is typical sectional drawing which shows another example of the organic EL element of this invention. It is typical sectional drawing which shows another example of the organic EL 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 which has carrier transport ability 7 Back electrode

Claims (10)

In an organic electroluminescent device composed of one or more organic compound layers sandwiched between a pair of electrodes, at least one of which is transparent or translucent,
A charge transporting polyether comprising at least one organic compound layer 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: 1 or more types, and at least one of the organic compound layers is transitioned from the excited triplet state of the electron energy level to the ground state or to the ground state via the excited triplet state. An organic electroluminescence device comprising a light-emitting polymer that emits light.

(In the general formulas (I-1) and (I-2), Ar represents a substituted or unsubstituted monovalent aromatic group, and X represents a substituted or unsubstituted divalent aromatic group. T represents a divalent straight-chain hydrocarbon having 1 to 6 carbon atoms or a branched hydrocarbon having 2 to 10 carbon atoms, and k and l represent 0 or 1.)   The organic compound layer is composed of at least a light emitting layer and an electron transport layer, and at least one of the light emitting layer and the electron transport layer is selected from the structures represented by the general formulas (I-1) and (I-2) Containing one or more charge transporting polyethers composed of a repeating unit containing at least one kind as a partial structure, and the light emitting layer is excited by a transition from an excited triplet state to a ground state of an electron energy level The organic electroluminescent device according to claim 1, comprising at least one luminescent polymer that emits light upon transition to a ground state via a triplet state.   The organic electroluminescent element according to claim 2, wherein the light emitting layer contains a charge transporting material.   The organic compound layer is composed of at least a hole transport layer, a light emitting layer, and an electron transport layer, and at least one of the hole transport layer and the electron transport layer is represented by the general formulas (I-1) and (I-2). Containing at least one charge transporting polyether comprising a repeating unit containing at least one selected from the structures shown as a partial structure, wherein the light emitting layer is changed from an excited triplet state of an electron energy level to a ground state. 2. The organic electroluminescent device according to claim 1, comprising at least one luminescent polymer that emits light by a transition or a transition to a ground state via an excited triplet state.   The organic light emitting device according to claim 4, wherein the light emitting layer includes a charge transporting material.   The organic compound layer is composed of at least a hole transport layer and a light emitting layer, and at least one of the hole transport layer and the light emitting layer is selected from the structures represented by the general formulas (I-1) and (I-2) Containing one or more charge transporting polyethers composed of a repeating unit containing at least one kind as a partial structure, and the light emitting layer is excited by a transition from an excited triplet state to a ground state of an electron energy level The organic electroluminescent device according to claim 1, comprising at least one luminescent polymer that emits light upon transition to a ground state via a triplet state.   The organic electroluminescent device according to claim 6, wherein the light emitting layer contains a charge transporting material.   The organic compound layer is composed of a light emitting layer having at least a charge transporting ability, and the light emitting layer partially includes at least one selected from the structures represented by the general formulas (I-1) and (I-2). Contains one or more charge-transporting polyethers composed of repeating units included as a structure, and the light-emitting layer further transitions from the excited triplet state to the ground state of the electron energy level or through the excited triplet state. The organic electroluminescent device according to claim 1, comprising at least one luminescent polymer that emits light upon transition to the ground state.   The organic electroluminescent device according to claim 8, wherein the light emitting layer contains a charge transporting material. A charge transporting polyether 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 is represented by the following general formula (II). 2. The organic electroluminescent device according to claim 1, which is a charge transporting polyether.

(In the general formula (II), A represents at least one selected from the structures represented by the general formulas (I-1) and (I-2), and R represents a hydrogen atom, an alkyl group, substituted or unsubstituted. Of the aryl group, or a substituted or unsubstituted aralkyl group, and p represents an integer of 5 to 5000.)

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