JP2005220145A - Material for organic electroluminescent element and organic electroluminescent element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for an organic electroluminescent element having a low driving voltage, high luminous efficiency and high heat resistance and to provide the organic electroluminescent element using the same. <P>SOLUTION: The material for the organic electroluminescent element comprises a copolymer of a unit represented by general formula [1] äwherein, A denotes a nonconjugated trivalent organic residue; B denotes a bivalent organic residue; C denotes a monovalent organic residue represented by general formula [2] (wherein, R<SP>1</SP>to R<SP>7</SP>denote each a binding site, a hydrogen atom or the like; and X denotes a direct bond or the like), a unit having an amino group and a unit represented by general formula [3] (wherein, D denotes a nonconjugated trivalent organic residue; E denotes a bivalent organic residue or the like; and F denotes a monocycle or the like having ≥1 substituted or unsubstituted heteroatoms)}. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel organic electroluminescent device material and an organic electroluminescent (EL) device having high luminous efficiency using the same.

  An electroluminescent element using an organic substance is promising for use as a solid light emitting type inexpensive large-area full-color display element, and many developments have been made. In general, an organic electroluminescent element is composed of a light emitting layer and a pair of counter electrodes sandwiching the layer. In light emission, when an electric field is applied between both electrodes, electrons are injected from the cathode side, holes are injected from the anode side, the electrons recombine with holes in the light emitting layer, and the energy level starts from the conduction band. It is a phenomenon in which energy is released as light when returning to the valence band.

Conventional organic electroluminescent elements have a higher driving voltage and lower luminance and luminous efficiency than inorganic EL elements. Further, the characteristic deterioration has been remarkably not put into practical use.
In recent years, an organic electroluminescent device in which a thin film containing an organic compound having a high fluorescence quantum efficiency that emits light at a low voltage of 10 V or less has been reported and attracted attention (see Non-Patent Document 1). This method uses a metal chelate complex as a light emitting layer and an amine compound as a hole injection layer to obtain high luminance green light emission, and the luminance reaches several thousand cd / m ² at a DC voltage of 6 to 7V. ing. However, the production of an organic electroluminescent device involving an organic compound vapor deposition operation has a problem in productivity, and it is desirable to create a coating-type device from the viewpoint of simplifying the manufacturing process and increasing the area.

  A polyphenylene vinylene polymer is known as a light-emitting material of an organic electroluminescent device used for producing an organic electroluminescent device of a coating method advantageous for productivity (see Non-Patent Documents 2 and 3), but a light-emitting portion. Has a problem in that it is difficult to control the concentration of the light-emitting material and to delicately control the color tone and light emission intensity. Similarly, there is a dye-dispersed polymer as an organic electroluminescent element using a coating method. For example, it is an element (see Patent Document 1) in which a low molecular weight dye or the like is dispersed in polyvinyl carbazole, and these have various functions such as electron transport property, electron injection property, hole transport property, hole injection property, and light emission property. The material which has it can be mixed and used for multiple light emitting elements.

  Conventional polyvinyl carbazole has a relatively high durability because of its high glass transition point, but has a high driving voltage and insufficient hole mobility and film-forming properties, resulting in low luminous efficiency and practical problems. In order to improve these problems, various carbazole derivative polymers and copolymers have been proposed. For example, a copolymer of a carbazole derivative and a diamine derivative (see Patent Documents 2 and 3), a copolymer of a carbazole derivative and an oxadiazole derivative (see Patent Documents 4 to 6), and a polymer having a special carbazole unit (Patent Document) 7 and 8), both of which have low light emission luminance and light emission efficiency and short lifetime.

  The driving voltage of a dye-dispersed element using polyvinyl carbazole and a derivative polymer thereof is higher than that of an organic electroluminescent element using a conjugated polymer light-emitting material such as a polyphenylene vinylene derivative. This is presumably because the carrier mobility of the non-conjugated polymer material used in the dye-dispersed element is lower than that of the polymer light-emitting material of the polyphenylene vinylene derivative. Since the display device leads to low power consumption, the driving voltage is one of the characteristics that are attracting attention, and improvement is also desired in the non-conjugated polymer material used for the dye-dispersed element.

Furthermore, it is easy to finely adjust the carrier balance when blending various hole transport materials and electron transport materials in a polymer, but the glass transition temperature of the coating film can be adjusted by blending. Decreases, causing a significant decrease in device life. Therefore, it is considered important to improve the heat resistance of the film.
JP-A-4-212286 JP 2002-124390 A JP 2002-37817 A Japanese Patent Laid-Open No. 11-60660 JP-A-11-307253 JP 2000-159846 A JP 2002-105445 A JP 2002-302516 A Applied Physics Letters, 51, 913, 1987 Advanced Materials, Volume 2, Page 4 1992 Advanced Material 9, 551 pages 1997

As an organic electroluminescent element using a coating method, there is a dye-dispersed polymer. These materials having various functions such as electron transporting property, electron injecting property, hole transporting property, hole injecting property, and light emitting property can be mixed and used in a plurality of light emitting elements. However, there is a problem that the luminous efficiency is low and the heat resistance of the film is low in the case of a blend film.
An object of the present invention is to provide an electroluminescent element material having high luminous efficiency and an electroluminescent element material having high heat resistance.

The present invention relates to a material for an organic electroluminescent device comprising a unit represented by the following general formula [1], a unit having an amino group, and a copolymer of a unit represented by the following general formula [3].
General formula [1]

［式中R¹〜R⁷は結合部位、水素原子もしくは置換基を表し、
Xは直接結合、−O−、−S−、−Se−、−NH−、−NR⁸−（R⁸はアルキル基またはアリール基を表す。）、−S (＝O)₂−、−（CO）−、−COO−、−OCO−、−CH₂−を示し、
R¹〜R⁷は互いに結合してアリール環を形成しても良く、さらにそのアリール環に置換基を有しても良い。］ [Wherein A represents a non-conjugated trivalent organic residue,
B represents a divalent organic residue selected from the group consisting of a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group,
C represents a monovalent organic residue represented by the following general formula [2]. ]
General formula [2]

[Wherein R ^{1 to} R ⁷ represent a bonding site, a hydrogen atom or a substituent,
X is a direct bond, —O—, —S—, —Se—, —NH—, —NR ⁸ — (R ⁸ represents an alkyl group or an aryl group), —S (═O) ₂ —, — ( CO) -, - COO -, - OCO -, - CH 2 - indicates,
R ^{1 to} R ⁷ may be bonded to each other to form an aryl ring, and further the aryl ring may have a substituent. ]

General formula [3]

[Wherein D represents a non-conjugated trivalent organic residue,
E represents a direct bond, or a divalent organic residue selected from the group consisting of a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group,
F represents a substituted or unsubstituted monocyclic ring having one or more heteroatoms or a condensed polycyclic ring having one or more heteroatoms. ]

The present invention relates to the material for an organic electroluminescent element, wherein the general formula [2] is a monovalent organic residue represented by the following general formula [3].
General formula [4]

[Wherein R ^{1 to} R ¹⁰ represent a bonding site, a hydrogen atom or a substituent. ]
The present invention relates to an organic light emitting device material comprising the above organic electroluminescent device material and a light emitting material capable of emitting light from triplet excitons.

The present invention also relates to an organic electroluminescent device comprising a light emitting layer or a plurality of organic compound thin films including a light emitting layer formed between a pair of electrodes, wherein at least one layer comprises the above organic electroluminescent device material. It relates to an element.

  According to the present invention, a material for an electroluminescent element having high luminous efficiency and high heat resistance and an electroluminescent element using the same can be provided.

  The present invention is characterized by using a novel polymer represented by the general formula [1] and an organic electroluminescence device using the same.

  In the general formula [1], A and D represent any trivalent organic residue capable of forming a non-conjugated main chain skeleton having B—C and EF in the side chain. Examples are shown in G-1 to G-12 of Table 1, but are not limited thereto.

The polymerization mode of the non-conjugated main chain skeleton monomer when forming the polymer can be polymerized by vinyl polymerization such as radical polymerization, cationic polymerization, anion polymerization, condensation polymerization, ring-opening polymerization, and various polymerization reactions. The method is not particularly limited, but in the present invention, a polymer formation reaction by polymerization of a vinyl polymerization monomer is particularly preferable.
In addition, a monovalent organic residue composed of B and C in the general formula [1], a monovalent organic residue composed of E and F in the general formula [3], or an amino group having an amino group in the side chain Even if the organic residue containing a group is not introduced at the stage of the non-conjugated main chain skeleton monomer, it may be introduced and modified after the non-conjugated main chain skeleton is formed.

In the copolymer of the unit represented by the general formula [1] and the unit having an amino group, the amino group of the unit having an amino group is present in the main chain or side chain of the copolymer.
Preferably, the unit has a structure represented by the following general formula [4].
General formula [4]

Wherein H and I are each independently a divalent group selected from one or more selected from the group consisting of a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, a substituted or unsubstituted ethenyl group Represents an organic residue (however, when an ethenyl group is selected, it is between two arylene groups or heteroarylene groups). ]

Further, a unit having a structure represented by the following general formula [5] is preferable.
General formula [5]

[Wherein H, I and J are each independently a divalent selected from the group consisting of a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, a substituted or unsubstituted ethenyl group. (However, when an ethenyl group is selected, it is a case between two arylene groups or heteroarylene groups.) ]

The unit having an amino group is more preferably represented by the following general formula [6].
General formula [6]

[Wherein H represents a divalent organic residue selected from the group consisting of a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, a substituted or unsubstituted ethenyl group (provided that , An ethenyl group is selected between two arylene groups or heteroarylene groups.) L and M are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups 1 or 2 selected from the group represents a monovalent organic residue, and G represents a non-conjugated trivalent organic residue. ]

  More preferred examples include the structures shown in N-2 to N-12 in Table 2 below, but the invention is not limited thereto.

  The arylene group in the general formulas [1] to [3] is preferably a monocyclic or condensed arylene group having 6 to 60 carbon atoms, more preferably 6 to 40 carbon atoms, and still more preferably 6 to 30 carbon atoms. An arylene group. Specific examples include phenylene, biphenylene, naphthalenediyl, anthracenediyl, phenanthroline diyl, pyrenediyl, triphenylenediyl, benzophenanthroline diyl, perylenediyl, pentaphenylenediyl, pentacenediyl, and the like. good.

  The heteroarylene group in the general formulas [1] to [3] is preferably a monocyclic or condensed aromatic heterocyclic group having 4 to 60 carbon atoms, more preferably at least a nitrogen atom, an oxygen atom or a sulfur atom. It is a monocyclic or condensed aromatic heterocyclic group having 4 to 60 carbon atoms containing one, and more preferably a 5- or 6-membered aromatic heterocyclic group having 4 to 30 carbon atoms. Specific examples of the aromatic heterocyclic group include pyrrole diyl, furandyl, thienylene, pyridinediyl, pyridazinediyl, pyrimidinediyl, pyrazinediyl, quinolinediyl, isoquinolinediyl, cinnolinediyl, quinazolinediyl, quinoxalinediyl, phthalazinediyl, pteridinediyl, acridinediyl, phenidinediyl Examples thereof include diyl and phenanthroline diyl, and these groups may have a substituent.

  The substituent of the compound in the present invention is a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted. Substituted thioalkoxy group, cyano group, amino group, mono- or di-substituted amino group, hydroxyl group, mercapto group, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylthio group, substituted or unsubstituted aryl group, substituted Alternatively, it represents an unsubstituted heteroaryl group, and the substituents may form a substituted or unsubstituted ring with adjacent substituents.

  Examples of the substituted or unsubstituted aryl group include phenyl group, biphenylenyl group, triphenylenyl group, tetraphenylenyl group, 3-nitrophenyl group, 4-methylthiophenyl group, 3,5-dicyanophenyl group, o-, m- And p-tolyl group, xylyl group, o-, m- and p-cumenyl group, mesityl group, pentarenyl group, indenyl group, naphthyl group, anthracenyl group, azulenyl group, heptaenyl group, acenaphthylenyl group, phenalenyl group, fluorenyl group, Anthryl group, anthraquinonyl group, 3-methylanthryl group, phenanthryl group, pyrenyl group, chrysenyl group, 2-ethyl-1-chrysenyl group, picenyl group, perylenyl group, 6-chloroperylenyl group, pentaphenyl group, pentacenyl group, tetra Phenylenyl group, hexaphenyl Group, hexacenyl group, rubicenyl group, coronenyl groups, trinaphthylenyl groups, heptacenyl groups, pyranthrenyl groups, there is ovalenyl group.

  Examples of the substituted or unsubstituted heteroaryl group include thionyl group, furyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, indolyl group, quinolyl group, isoquinolyl group, phthalazinyl group, Quinoxalinyl group, quinazolinyl group, carbazolyl group, acridinyl group, phenazinyl group, furfuryl group, isothiazolyl group, isoxazolyl group, furazanyl group, phenoxazinyl group, benzothiazolyl group, benzoxazolyl group, benzimidazolyl group, 2-methylpyridyl group, 3 -A cyanopyridyl group and the like.

  Mono- or di-substituted amino groups include methylamino, dimethylamino, ethylamino, diethylamino, dipropylamino, dibutylamino, diphenylamino, bis (acetoxymethyl) amino, bis (acetoxy) And ethyl) amino group, bis (acetoxypropyl) amino group, bis (acetoxybutyl) amino group, and dibenzylamino group.

  Substituted or unsubstituted alkyl groups include methyl, ethyl, propyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, isooctyl , Stearyl group, trichloromethyl group, trifluoromethyl group, cyclopropyl group, cyclohexyl group, 1,3-cyclohexadienyl group, 2-cyclopenten-1-yl group, 2,4-cyclopentadiene-1-ylidenyl group, etc. There is.

  Examples of the substituted or unsubstituted alkoxy group include methoxy group, ethoxy group, propoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, 2-ethylhexyloxy group, stearyloxy Group, trifluoromethoxy group and the like.

  Examples of the substituted or unsubstituted thioalkoxy group include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a sec-butylthio group, a tert-butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, and an octylthio group.

  Examples of the substituted or unsubstituted aryloxy group include a phenoxy group, a p-tert-butylphenoxy group, and a 3-fluorophenoxy group.

  Examples of the substituted or unsubstituted arylthio group include a phenylthio group and a 3-fluorophenylthio group.

  Preferred substituents are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group. Further, adjacent substituents form an aliphatic, carbocyclic aromatic, heterocyclic aromatic or heterocyclic ring which may contain a 5- to 7-membered oxygen atom, nitrogen atom, sulfur atom, etc. It may also have a substituent at any position of these rings.

  Monocycles having one or more heteroatoms in the present invention include thiophene, pyrrole, silole, furan, pyrazole, imidazole, oxazole, thiazole, oxadiazole, triazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, etc. The condensed polycycle having one or more heteroatoms includes benzofuran, indole, benzothiophene, benzimidazole, benzothiazole, benzoxazole, quinolineisoquinoline, coumarin, quinoline, dibenzofuran, phenothiazine, phenanthroline and the like.

The copolymer of the unit represented by the general formula [1] of the present invention and the unit having an amino group may be a random, block, or graft copolymer, and has an intermediate structure thereof. It may be a polymer having, for example, a random copolymer having block properties.
The copolymer of the unit represented by the general formula [1] and the unit having an amino group of the present invention further includes styrene and derivatives thereof, acrylic acid and derivatives thereof, maleic acid and derivatives thereof, organic acid vinyl esters, and vinylcarbazole. It is good also as a copolymer with these.

The weight of the organic electroluminescent element material of the present invention is not particularly limited considering the heat resistance and the stability of the thin film state. It is preferably 500,000.

  B in the general formula [1] of the present invention is a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, or a combination of two or more of the arylene group or heteroarylene group. . When the arylene group or heteroarylene group has a substituent, the substituents may be combined to form a new ring.

  E in the general formula [3] in the present invention is a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, or a combination of two or more of the arylene group or heteroarylene group. When the arylene group or heteroarylene group has a substituent, the substituents may be combined to form a new ring. When the substituent of the general formula [3] is an aryl group or a heteroaryl group, this ring may further have a substituent. The general formula [3] preferably includes structures shown by O-1 to O-12 in Table 3 below, but is not limited thereto.

  Although the structural example of the unit used for a polymer is specifically shown in Table 4, the polymer of this invention is not limited to the following representative examples. Table 4 shows only the structure of each unit monomer, and does not show its polymerization form. Moreover,% in Table 4 represents mol%.

  The material for an organic light-emitting device of the present invention may be used by mixing with other light-emitting materials, holes or electron transporting compounds in the same layer. Since the polymer of the present invention is excellent in light emitting property and hole transporting property, it can be used effectively as a hole transporting light emitting material.

  The organic light emitting device material of the present invention can be used as any of a hole injection material, a hole transport material, a light emitting material, an electron transport material, and an electron injection material. The organic light emitting device material of the present invention may be used alone or in combination with other organic materials or inorganic materials. The organic material used in combination may be a low molecular organic material or a high molecular organic material. Moreover, it is also possible to use it by laminating and coating with other polymer organic materials. Furthermore, it can be used by mixing with a low molecular weight compound or by laminating. In this case, the low molecular weight compound may be mixed with a polymer binder and applied, or may be laminated by a method such as vacuum deposition or sputtering. Hereinafter, although the specific example of the organic light emitting element material of this invention is shown, they do not limit this invention.

  The light emitting materials include those that emit light from singlet excitons, those that emit light from triplet excitons, and those that emit light from both, and any of these light emitting materials is used in the organic light emitting device material of the present invention. Is possible. As the light-emitting material or dopant material that can be used in the light-emitting layer together with the organic light-emitting device material of the present invention, polyalkylfluorene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polythiophene derivatives, and other light-emitting polymers can be used. In addition, anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein, perylene, phthaloperylene, naphthaloperylene, perinone, phthaloperinone, naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, aldazine, bis Benzoxazoline, bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, benzoquinoline metal complex, imine, diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran, polymethine, merocyanine, imidazole chelating oxinoid compound, Examples include, but are not limited to, quinacridone, rubrene, and fluorescent dyes for dye laser and sensitization. Not shall.

A triplet light-emitting metal complex is particularly preferred as the light-emitting material or dopant material that can be used in the light-emitting layer together with the organic light-emitting device material of the present invention. Examples of triplet-emitting metal complexes that can emit light from triplet excitons include the iridium complex Ir (ppy) ₃ (Tris-Ortho-Metalated Complex of Iridium (III) with 2-Phenylpyridine). It has been. The green light emitting device using Ir (ppy) ₃ achieves an external quantum yield of 8%, surpassing the external quantum yield of 5%, which was previously considered the limit of organic light emitting devices (Applied Physics Letters 75, 4 (1999)). Other Ir complex compounds and metal coordination porphyrin compounds can be used with the organic light emitting device material of the present invention, but are not limited thereto.

  If necessary, a hole injection material or an electron injection material can be further used for the light emitting layer. The organic electroluminescent element can prevent a decrease in luminance and lifetime due to quenching by adopting a multilayer structure. If necessary, a light emitting material, a dopant material, a hole injection material, and an electron injection material can be used in combination. Further, with the dopant material, it is possible to improve light emission luminance and light emission efficiency and to obtain red or blue light emission. Moreover, the hole injection zone, the light emitting layer, and the electron injection zone may each be formed with a layer configuration of two or more layers. In that case, in the case of the hole injection zone, the layer that injects holes from the electrode is a hole injection layer, and the layer that receives holes from the hole injection layer and transports holes to the light emitting layer is a hole transport layer. Call. Similarly, in the case of an electron injection zone, a layer for injecting electrons from an electrode is referred to as an electron injection layer, and a layer for receiving electrons from the electron injection layer and transporting electrons to a light emitting layer is referred to as an electron transport layer. Each of these layers is selected and used depending on factors such as the energy level of the material, heat resistance, and adhesion to the organic layer or metal electrode.

  As a hole injection material, it has the ability to transport holes, has a hole injection effect from the anode, an excellent hole injection effect for the light emitting layer or the light emitting material, and excitons generated in the light emitting layer. Examples thereof include compounds that prevent movement to an electron injection zone or an electron injection material and have an excellent thin film forming ability. Specifically, PEDOT, phthalocyanine derivative, naphthalocyanine derivative, porphyrin derivative, oxazole, oxadiazole, triazole, imidazole, imidazolone, imidazolethione, pyrazoline, pyrazolone, tetrahydroimidazole, hydrazone, acyl hydrazone, polyarylalkane, stilbene, There are butadiene, benzidine type triphenylamine, styrylamine type triphenylamine, diamine type triphenylamine, and their derivatives, and polymer materials such as polyvinyl carbazole, polysilane, conductive polymer, etc. Is not to be done.

   As an electron injection material, it has the ability to transport electrons, has a hole injection effect from the cathode, and an excellent electron injection effect for the light-emitting layer or light-emitting material, and hole injection of excitons generated in the light-emitting layer Examples thereof include compounds that prevent migration to the zone and have an excellent thin film forming ability. For example, there are fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, anthrone and their derivatives. However, it is not limited to these. Further, it can be sensitized by adding an electron accepting substance to the hole injecting material and an electron donating substance to the electron injecting material.

  Since the organic light emitting device material of the present invention has a high glass transition point and melting point, it has improved resistance (heat resistance) to Joule heat generated in the organic layer, between the organic layers, or between the organic layer and the metal electrode during electroluminescence. Therefore, when it is used as an organic electroluminescent element material, it exhibits high emission luminance and is advantageous when emitting light for a long time.

  The film formation method for the organic light emitting device material of the present invention is not particularly limited. For example, a vacuum deposition method from a powder state, a method of coating after dissolving in a solvent (for example, an inkjet method, a spray method, a printing method, a spin method). A coating method, a casting method, a dipping method, a bar coating method, a roll coating method, etc.) can be used, but a coating method is preferred from the viewpoint of simplification of the element manufacturing process, workability, and large area. Solvents used in the coating method include organic halogen solvents such as dichloroethane, dichloromethane and chloroform, ether solvents such as tetrahydrofuran and 1.4-dioxane, aromatic hydrocarbon solvents such as toluene and xylene, dimethyl An amide solvent such as formamide and dimethylacetamide, an ester solvent such as ethyl acetate and butyl acetate, or a mixed solvent thereof may be used. Although it depends on the structure and molecular weight of the polymer, the film is usually formed using a solution of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, of a solvent.

  An organic EL element is an element in which a single-layer or multilayer organic thin film is formed between an anode and a cathode. In the case of the single layer type, a light emitting layer is provided between the anode and the cathode. The light-emitting layer contains a light-emitting material, and may further contain a hole-injecting material or an electron-injecting material in order to transport holes injected from the anode or electrons injected from the cathode to the light-emitting material. The multi-layer type includes (anode / hole injection band / light emitting layer / cathode), (anode / light emitting layer / electron injection band / cathode), and (anode / hole injection band / light emitting layer / electron injection band / cathode). There are organic EL elements stacked in a configuration.

As the conductive material used for the anode of the organic EL element, those having a work function larger than 4 eV are preferable, and carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium, etc. Further, alloys thereof, ITO substrates, metal oxides such as tin oxide and indium oxide called NESA substrates, and organic conductive resins such as polythiophene and polypyrrole are used.
As the conductive material used for the cathode, those having a work function smaller than 4.0 eV are preferable. Magnesium, barium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, etc. and alloys thereof However, it is not limited to these. If necessary, the anode and the cathode may be formed of two or more layers.

  The organic EL element using the organic light-emitting element material of the present invention is a flat panel display such as a wall-mounted television, a flat light emitter, a light source such as a copying machine or a printer, a light source such as a liquid crystal display or instrument, a display plate, It can be applied to beacon lamps, etc., and its industrial value is very large.

Hereinafter, the present invention will be described in more detail based on examples. In the description, parts represent parts by weight and% represents% by weight.
Production Example 1
Synthesis method of P-1

Under a dry nitrogen stream, p-bromoiodobenzene (15.4 g, 54.4 mmol), carbazole (10.0 g, 59.8 mmol), Cu powder 0.3 g, K ₂ CO ₃ (7.9 g, 57.0 mmol) and 1,3- 100 ml of dimethylimidazilijinone was added and stirred at 190 ° C. for 18 hours. The reaction solution was poured into 700 ml of water, and the precipitate was filtered and dried at 70 ° C. to obtain a crude product. Thereafter, it was isolated and purified by silica gel column chromatography to obtain compound (1). Yield 55%.
A condenser tube was attached to the four-necked flask, and THF (30 ml) was added to Compound (1) (2.5 g, 7.8 mmol) and 4-vinylphenylboronic acid (1.72 g, 11.6 mmol) and stirred. 2M K ₂ CO ₃ aq (30 ml) was added thereto. Tetrakistriphenylphosphine palladium (0) (Pd (PPh ₃ )) (200 mg, 174 mmol) and THF (10 ml) were added, and the mixture was cyclized at 80 ° C. for 24 hours. Purification by column chromatography and methanol reprecipitation gave compound (2). The yield was 62%.
0.4g, 0.2g, and 0.4g of compound (2), compound (3), and compound (4) were placed in a Schlenk flask, respectively, and vacuum degassing was repeated several times. Azobisisobutyronitrile (0.02 g) and THF (2.7 ml) were added thereto, and the mixture was stirred at 70 ° C. for 9 hours. The reaction liquid has become viscous. Purification was performed by methanol reprecipitation. The yield was 90%.

Examples using the organic light-emitting device material of the present invention are specifically shown below, but the present invention is not limited thereto.
Example 1
A PEDOT / PSS (poly (3,4-ethylenedioxy) -2,5-thiophene / polystyrene sulfonic acid) film was formed into a film thickness of 40 nm by spin coating on a cleaned glass plate with an ITO electrode. P-1 and Ir (ppy) ₃ (3%) described in 1 were dissolved and dispersed in dichloroethane at a concentration of 1.0 wt%, and a light emitting layer having a thickness of 50 to 100 nm was obtained by a spin coating method. An electrode was formed on this coated substrate with a film thickness of 20 nm of Ca and 200 nm of Al by a vacuum deposition method, and the organic EL element 1 was produced.

Comparative Example 1
On the washed glass plate with ITO electrode, PEDOT was formed into a film thickness of 40 nm by spin coating, and the following compound (6) described in JP-A No. 2002-37817 and Ir (ppy) ₃ (3%) Further, an electron transport material (compound (4)) (35%) was dissolved and dispersed in toluene or xylene at a concentration of 1.0 wt%, and a light emitting layer having a thickness of 50 to 100 nm was obtained by a spin coating method. An electrode was formed on this coated substrate with a film thickness of 20 nm of Ca and 200 nm of Al by a vacuum deposition method, and an organic EL element 4 was produced.

化合物（５）

Compound (5)

Comparative Example 2
PEDOT was formed into a film thickness of 40 nm by spin coating on a cleaned glass plate with an ITO electrode, and compound (7) and Ir (ppy) ₃ (3%) described in JP-A No. 11-307253 were 1 It was dissolved and dispersed in toluene or xylene at a concentration of 0.0 wt%, and a light emitting layer having a thickness of 50 to 100 nm was obtained by a spin coating method. An electrode was formed on this coated substrate with a film thickness of 20 nm of Ca and 200 nm of Al by a vacuum deposition method, and an organic EL element 4 was produced.

Table 5 shows the EL characteristics of Example 1 and Comparative Examples 1 and 2.

  The organic EL device of the present invention achieves low driving voltage, light emission efficiency, and light emission brightness, and is used together with a light emitting substance, a light emission auxiliary material, a hole transport material, an electron transport material, and a sensitizer. However, the resin, the electrode material, etc. and the device manufacturing method are not limited.

As is clear from Table 5, the electroluminescent element (element 1) using the organic electroluminescent element material of the present invention and the electroluminescent element using the compound (6) and the compound (7) which are not copolymers ( Comparing the element 2 and the element 3), it can be confirmed that the former has lower driving voltage and higher efficiency light emission.

Table 6 shows the glass transition temperatures of the light emitting layers in Example 1 and Comparative Examples 1 and 2.

As is apparent from Table 6, in the device 2 and the device 3 using the compound (6) and the compound (7), which are materials not copolymerized with the light emitting layer in the device 1 using the organic electroluminescent device material of the present invention. Comparing the light emitting layer, it can be seen that the former has a higher glass transition temperature.

Claims (4)

An organic electroluminescent element material comprising a unit represented by the following general formula [1], a unit having an amino group, and a copolymer of a unit represented by the following general formula [3].
General formula [1]

[Wherein A represents a non-conjugated trivalent organic residue,
B represents a divalent organic residue selected from the group consisting of a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group,
C represents a monovalent organic residue represented by the following general formula [2]. ]
General formula [2]

[Wherein R ^{1 to} R ⁷ represent a bonding site, a hydrogen atom or a substituent,
X is a direct bond, —O—, —S—, —Se—, —NH—, —NR ⁸ — (R ⁸ represents an alkyl group or an aryl group), —S (═O) ₂ —, — ( CO) -, - COO -, - OCO -, - CH 2 - indicates,
R ^{1 to} R ⁷ may be bonded to each other to form an aryl ring, and further the aryl ring may have a substituent. ]
General formula [3]

[Wherein D represents a non-conjugated trivalent organic residue,
E represents a direct bond, or a divalent organic residue selected from the group consisting of a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group,
F represents a substituted or unsubstituted monocyclic ring having one or more heteroatoms or a condensed polycyclic ring having one or more heteroatoms. ] The organic electroluminescent element material according to claim 1, wherein the general formula [2] is a monovalent organic residue represented by the following general formula [3].
General formula [4]

[Wherein R ^{1 to} R ¹⁰ represent a bonding site, a hydrogen atom or a substituent. ] An organic electroluminescent element material comprising the organic electroluminescent element material according to claim 1 and a luminescent material capable of emitting light from triplet excitons. In the organic electroluminescent element formed by forming the light emitting layer or a plurality of layers of organic compound thin films including the light emitting layer between the pair of electrodes, at least one layer contains the material for an organic electroluminescent element according to any one of claims 1 to 3. Organic electroluminescent device.