WO2011016543A1

WO2011016543A1 - Organic electroluminescent element and process for production thereof

Info

Publication number: WO2011016543A1
Application number: PCT/JP2010/063350
Authority: WO
Inventors: 誠安立
Original assignee: 住友化学株式会社
Priority date: 2009-08-07
Filing date: 2010-08-06
Publication date: 2011-02-10
Also published as: JP2011054954A; TW201114321A

Abstract

Disclosed is an organic electroluminescent element which can be produced in a simple manner, can emit light at a luminance of 100 cd/m², and has a low driving voltage. Specifically disclosed is an organic electroluminescent element which comprises an anode, a cathode, and a light-emitting layer arranged between the anode and the cathode and comprising a light-emitting material, and additionally comprises an organic layer arranged between the anode and the light-emitting layer, wherein the anode is produced by forming a coupling film on an electrode and treating the surface of the coupling film, and the organic layer comprises a polymeric compound having a repeating unit represented by formula (2) [wherein ring A and ring B are same as or different from each other, and independently represent an aromatic ring having a bond on a ring moiety thereof; Y₁ represents -O-, -S-, or -C(=O)-; and R^b represents a monovalent organic group].

Description

Organic electroluminescence device and method for manufacturing the same

The present invention relates to an organic electroluminescence element and a manufacturing method thereof.

Organic electroluminescence (organic EL) displays are attracting attention as next-generation displays. An organic EL element used for an organic EL display includes an anode, a cathode, and a light emitting layer disposed between the anode and the cathode, and holes and electrons injected from the anode and the cathode, respectively. Light is emitted by recombination in the light emitting layer.

However, in order to realize commercial use of the organic EL element, it is necessary to drive the element at a lower voltage to reduce power consumption, and a technique for increasing the mobility of carriers is being sought.

In an organic EL element, as a transparent conductive electrode that transmits light and injects holes, indium oxide, zinc oxide, tin oxide, and their composites, indium tin oxide (ITO), indium zinc -A conductive material made of oxide or the like is used, and by providing a layer that assists the movement of holes in the light emitting layer between this electrode and the light emitting layer, the mobility of holes that are carriers is increased. It is done.

As an organic electroluminescence device that emits light at a low driving voltage, Patent Document 1 discloses a mixture of poly (ethylenedioxythiophene) and polystyrenesulfonic acid (hereinafter referred to as “PEDOT: PSS”) on the transparent conductive electrode. There has been proposed an organic electroluminescence device in which layers each including (a) are laminated. However, since PEDOT: PSS is strongly acidic, the operability is poor and there is a problem that the production of an organic electroluminescence device is not easy.

Patent Document 2 discloses that a skeleton polymer containing a tricyclic arylamine in the main chain of a fluorene-based photoelectron polymer has excellent conductivity, suggesting the possibility of providing high device efficiency at low voltage. ing. However, although this polymer is used as a light emitting layer of an organic EL device, the function of increasing the efficiency of injecting or transporting holes into the light emitting layer is not described.

Special Table 2000-514590 JP-T-2006-511659

Therefore, an object of the present invention is to provide an organic electroluminescence element that is easy to manufacture and has a low driving voltage that emits light with a luminance (for example, 100 cd / m ² ) used in a normal device.

The present invention is an organic electroluminescent device having an anode, a cathode, a light emitting layer containing a light emitting material between the anode and the cathode, and an organic layer between the anode and the light emitting layer. And
The anode is an electrode

[Wherein, M ¹ represents an atom belonging to Group 4, Group 5, Group 6, Group 13, Group 14 or Group 15 of the Periodic Table. X represents a monovalent organic group having a hetero atom. R ^a represents an alkyl group, an aryl group, an alkynyl group, an alkenyl group, an arylalkyl group, an arylalkenyl group or an arylalkynyl group. v1 is an integer of 1 to u. u represents the valence of M ¹ . When a plurality of X are present, they may be the same or different. When ^a plurality of R ^a are present, they may be the same or different. ]
It is immersed in a solution containing the compound represented by formula (1) and a solvent, or a solution containing the compound represented by formula (1) and a solvent is printed or coated on the electrode and dried, whereby the cup is placed on the electrode. It is formed by forming a ring film and then surface-treating the coupling film,
The organic layer has the formula

[Wherein, A ring and B ring are the same or different and each represents an aromatic ring having a bond on the ring; Y ₁ represents —O—, —S—, or —C (═O) —; R ^b represents a monovalent organic group. ]
A layer containing a polymer compound having a repeating unit represented by:
An organic electroluminescence device is provided.

In one certain form, the said surface treatment is UV ozone treatment.

In one certain form, the irradiation amount of UV in UV ozone treatment is 1 J / cm < ² > or more.

In certain one form, the M ¹ is a silicon atom or a titanium atom.

In one certain form, said Y < ₁ > is -O-.

In one certain form, the difference of the energy level of the highest occupied orbital (HOMO) of an anode and the energy level of the high molecular compound which has a repeating unit shown by Formula (2) is 0.5 eV or less. .

The present invention also provides a planar light source comprising the organic electroluminescence element.

Furthermore, this invention provides the display apparatus provided with the said organic electroluminescent element.

Since the organic electroluminescence device of the present invention does not use a strongly acidic material, it is easy to manufacture and has a low driving voltage for emitting light with a luminance of 100 cd / m ² .

It is a schematic cross section which shows the structure of the organic EL element which is one Embodiment of this invention.

<Explanation of terms>
Hereinafter, terms commonly used in this specification will be described. In this specification, the term “C _m -C _n ” (m, n is a positive integer satisfying m <n) for an alkyl group, an alkoxy group, an alkenyl group, or an alkynyl group is described together with this term. And the alkyl group, alkoxy group, alkenyl group, or alkynyl group formed has m to n carbon atoms.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group means an unsubstituted alkyl group and an alkyl group substituted with a halogen atom, amino group, hydroxy group, mercapto group, etc., and includes both a linear alkyl group and a cyclic alkyl group (cycloalkyl group). . The alkyl group may have a branch. The carbon number of the alkyl group is usually about 1 to 20, preferably about 1 to 15, and more preferably about 1 to 10. Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, 2- Ethylhexyl group, nonyl group, decyl group, 3,7-dimethyloctyl group, lauryl group, trifluoromethyl group, pentafluoroethyl group, perfluorobutyl group, perfluorohexyl group, perfluorooctyl group, trifluoropropyl group, Tridecafluoro-1,1,2,2-tetrahydrooctyl group, heptadecafluoro-1,1,2,2-tetrahydrodecyl group, aminopropyl group, aminooctyl group, aminodecyl group, mercaptopropyl group, mercaptooctyl group And mercaptodecyl group.

The alkoxy group means an unsubstituted alkoxy group and an alkoxy group substituted with a halogen atom or the like, and includes both a linear alkoxy group and a cyclic alkoxy group (cycloalkoxy group). The alkoxy group may have a branch. The number of carbon atoms of the alkoxy group is usually about 1 to 20, preferably about 1 to 15, and more preferably about 1 to 10. Specifically, methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group Octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group, lauryloxy group, trifluoromethoxy group, pentafluoroethoxy group, perfluorobutoxy group, methoxymethyloxy group, Examples include 2-methoxyethyloxy group.

The alkylthio group means an unsubstituted alkylthio group and an alkylthio group substituted with a halogen atom or the like, and includes both a linear alkylthio group and a cyclic alkylthio group (cycloalkylthio group). The alkylthio group may have a branch. The alkylthio group generally has about 1 to 20 carbon atoms, preferably about 1 to 15 carbon atoms, and more preferably about 1 to 10 carbon atoms. Specifically, methylthio group, ethylthio group, propylthio group, isopropylthio group, butylthio group, isobutylthio group, tert-butylthio group, pentylthio group, hexylthio group, cyclohexylthio group, heptylthio group, octylthio group, 2-ethylhexylthio group Group, nonylthio group, decylthio group, 3,7-dimethyloctylthio group, laurylthio group, trifluoromethylthio group and the like.

An aryl group is an atomic group obtained by removing one hydrogen atom bonded to a carbon atom constituting an aromatic ring from an aromatic hydrocarbon, and is substituted with an unsubstituted aryl group, a halogen atom, an alkoxy group, an alkyl group, or the like. Means a substituted aryl group. An aryl group having a benzene ring, having a condensed ring, or having two or more independent benzene rings or condensed rings bonded via a single bond or a divalent group, for example, an alkenylene group such as a vinylene group Is also included. The carbon number of the aryl group is usually about 6 to 60, preferably about 7 to 48, more preferably about 7 to 30. The aryl group includes a phenyl group, a C ₁ -C ₁₂ alkoxyphenyl group, a C ₁ -C ₁₂ alkylphenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, and a 9-anthracenyl group. And pentafluorophenyl group and the like, and C ₁ -C ₁₂ alkoxyphenyl group and C ₁ -C ₁₂ alkylphenyl group are preferable.

Specific examples of the C ₁ -C ₁₂ alkoxyphenyl group include methoxyphenyl group, ethoxyphenyl group, propyloxyphenyl group, isopropyloxyphenyl group, butoxyphenyl group, isobutoxyphenyl group, sec-butoxyphenyl group, tert-butoxy Phenyl group, pentyloxyphenyl group, hexyloxyphenyl group, cyclohexyloxyphenyl group, heptyloxyphenyl group, octyloxyphenyl group, 2-ethylhexyloxyphenyl group, nonyloxyphenyl group, decyloxyphenyl group, 3,7-dimethyl An octyloxyphenyl group, a lauryloxyphenyl group, etc. are illustrated.

Specific examples of the C ₁ -C ₁₂ alkylphenyl group include methylphenyl group, ethylphenyl group, dimethylphenyl group, propylphenyl group, mesityl group, methylethylphenyl group, isopropylphenyl group, butylphenyl group, isobutylphenyl group, Examples include sec-butylphenyl group, tert-butylphenyl group, pentylphenyl group, isoamylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, dodecylphenyl group and the like.

The aryloxy group means an unsubstituted aryloxy group and an aryloxy group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the aryloxy group is usually about 6 to 60, preferably about 7 to 48, more preferably about 7 to 30. Specific examples thereof include phenoxy group, C ₁ -C ₁₂ alkoxyphenoxy group, C ₁ -C ₁₂ alkylphenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, pentafluorophenyloxy group, etc. _{A 1} to C ₁₂ alkoxyphenoxy group and a C ₁ to C ₁₂ alkylphenoxy group are preferred.

Specific examples of the C ₁ -C ₁₂ alkoxyphenoxy group include methoxyphenoxy group, ethoxyphenoxy group, propyloxyphenoxy group, isopropyloxyphenoxy group, butoxyphenoxy group, isobutoxyphenoxy group, sec-butoxyphenoxy group, tert-butoxy group. Phenoxy group, pentyloxyphenoxy group, hexyloxyphenoxy group, cyclohexyloxyphenoxy group, heptyloxyphenoxy group, octyloxyphenoxy group, 2-ethylhexyloxyphenoxy group, nonyloxyphenoxy group, decyloxyphenoxy group, 3,7-dimethyl Examples include octyloxyphenoxy group, lauryloxyphenoxy group, and the like.

Specific examples of the C ₁ -C ₁₂ alkylphenoxy group include methylphenoxy group, ethylphenoxy group, dimethylphenoxy group, propylphenoxy group, 1,3,5-trimethylphenoxy group, methylethylphenoxy group, isopropylphenoxy group, butyl Phenoxy group, isobutylphenoxy group, sec-butylphenoxy group, tert-butylphenoxy group, pentylphenoxy group, isoamylphenoxy group, hexylphenoxy group, heptylphenoxy group, octylphenoxy group, nonylphenoxy group, decylphenoxy group, dodecylphenoxy group Etc. are exemplified.

The arylthio group means an unsubstituted arylthio group and an arylthio group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the arylthio group is usually about 6 to 60, preferably about 7 to 48, and more preferably about 7 to 30. Specific examples include a phenylthio group, a C ₁ -C ₁₂ alkoxyphenylthio group, a C ₁ -C ₁₂ alkylphenylthio group, a 1-naphthylthio group, a 2-naphthylthio group, a pentafluorophenylthio group, and the like.

The arylalkyl group means an unsubstituted arylalkyl group and an arylalkyl group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the arylalkyl group is usually about 7 to 60, preferably about 7 to 48, and more preferably about 7 to 30. Specifically, phenyl-C ₁ -C ₁₂ alkyl group, C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkyl group, C ₁ -C ₁₂ alkylphenyl-C ₁ -C ₁₂ alkyl group, 1-naphthyl -C ₁ ~ C ₁₂ alkyl group, 2-naphthyl -C ₁ ~ C ₁₂ alkyl group and the like.

The arylalkoxy group means an unsubstituted arylalkoxy group and an arylalkoxy group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the arylalkoxy group is usually about 7 to 60, preferably about 7 to 48, and more preferably about 7 to 30. Specifically, phenyl-C ₁ -C ₁₂ alkoxy group, C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkoxy group, C ₁ -C ₁₂ alkylphenyl-C ₁ -C ₁₂ alkoxy group, 1-naphthyl -C ₁ ~ C ₁₂ alkoxy groups, 2-naphthyl -C ₁ ~ C ₁₂ alkoxy group and the like.

The arylalkylthio group means an unsubstituted arylalkylthio group and an arylalkylthio group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the arylalkylthio group is usually about 7 to 60, preferably about 7 to 48, and more preferably about 7 to 30. Specifically, phenyl-C ₁ -C ₁₂ alkylthio group, C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkylthio group, C ₁ -C ₁₂ alkylphenyl -C ₁ -C ₁₂ alkylthio group, 1-naphthyl -C ₁ ~ C ₁₂ alkylthio groups, 2-naphthyl -C ₁ ~ C ₁₂ alkylthio group and the like.

The arylalkenyl group means an unsubstituted arylalkenyl group and an arylalkenyl group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the arylalkenyl group is usually about 8 to 60, preferably about 8 to 48, and more preferably about 8 to 30. Specific examples thereof include a phenyl-C ₂ -C ₁₂ alkenyl group, a C ₁ -C ₁₂ alkoxyphenyl-C ₂ -C ₁₂ alkenyl group, a C ₁ -C ₁₂ alkylphenyl-C ₂ -C ₁₂ alkenyl group, 1- And naphthyl-C ₂ -C ₁₂ alkenyl group, 2-naphthyl-C ₂ -C ₁₂ alkenyl group, and the like. C ₁ -C ₁₂ alkoxyphenyl-C ₂ -C ₁₂ alkenyl group, C ₂ -C ₁₂ alkylphenyl- C ₂ -C ₁₂ alkenyl groups are preferred.

Examples of the C ₂ -C ₁₂ alkenyl group include a vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 2-pentenyl group, 1-hexenyl group, Examples include 2-hexenyl group and 1-octenyl group.

The arylalkynyl group means an unsubstituted arylalkynyl group and an arylalkynyl group substituted with a halogen atom, an alkoxy group, an alkyl group or the like. The carbon number of the arylalkynyl group is usually about 8 to 60, preferably about 8 to 48, and more preferably about 8 to 30. Specific examples thereof include phenyl-C ₂ -C ₁₂ alkynyl group, C ₁ -C ₁₂ alkoxyphenyl-C ₂ -C ₁₂ alkynyl group, C ₁ -C ₁₂ alkylphenyl-C ₂ -C ₁₂ alkynyl group, 1- And naphthyl-C ₂ -C ₁₂ alkynyl group, 2-naphthyl-C ₂ -C ₁₂ alkynyl group, and the like. C ₁ -C ₁₂ alkoxyphenyl-C ₂ -C ₁₂ alkynyl group, C ₁ -C ₁₂ alkylphenyl- C ₂ -C ₁₂ alkynyl groups are preferred.

Examples of the C ₂ -C ₁₂ alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 1-pentynyl group, 2-pentynyl group, 1-hexynyl group, Examples include 2-hexynyl group and 1-octynyl group.

The monovalent heterocyclic group means a remaining atomic group obtained by removing one hydrogen atom from a heterocyclic compound, and is a monovalent substituted with a substituent such as an unsubstituted monovalent heterocyclic group or an alkyl group. A heterocyclic group of The carbon number of the monovalent heterocyclic group is usually about 3 to 60, preferably about 3 to 30, and more preferably about 3 to 20, excluding the carbon number of the substituent. Here, the heterocyclic compound is not only a carbon atom but also an oxygen atom, a sulfur atom, a nitrogen atom, a phosphorus atom, a boron atom, a silicon atom, as an element constituting a ring among organic compounds having a cyclic structure, Those containing hetero atoms such as selenium atom, tellurium atom and arsenic atom. Examples of the monovalent heterocyclic group include thienyl group, C ₁ -C ₁₂ alkylthienyl group, pyrrolyl group, furyl group, pyridyl group, C ₁ -C ₁₂ alkylpyridyl group, pyridazinyl group, pyrimidyl group, pyrazinyl group, A triazinyl group, a pyrrolidyl group, a piperidyl group, a quinolyl group, an isoquinolyl group and the like can be mentioned, among which a thienyl group, a C ₁ -C ₁₂ alkylthienyl group, a pyridyl group, and a C ₁ -C ₁₂ alkylpyridyl group are preferable.

The heterocyclic thio group means a group in which a hydrogen atom of a mercapto group is substituted with a monovalent heterocyclic group. Examples of the heterocyclic thio group include heteroarylthio groups such as a pyridylthio group, a pyridazinylthio group, a pyrimidylthio group, a pyrazinylthio group, and a triazinylthio group.

The amino group is an unsubstituted amino group and an amino group substituted with one or two substituents selected from an alkyl group, an aryl group, an arylalkyl group and a monovalent heterocyclic group (hereinafter referred to as a substituted amino group). ). The substituent may further have a substituent (hereinafter sometimes referred to as a secondary substituent). The carbon number of the substituted amino group is usually about 1 to 60, preferably about 2 to 48, more preferably about 2 to 40, not including the carbon number of the secondary substituent. Examples of the substituted amino group include methylamino group, dimethylamino group, ethylamino group, diethylamino group, propylamino group, dipropylamino group, isopropylamino group, diisopropylamino group, butylamino group, isobutylamino group, sec- Butylamino group, tert-butylamino group, pentylamino group, hexylamino group, heptylamino group, octylamino group, 2-ethylhexylamino group, nonylamino group, decylamino group, 3,7-dimethyloctylamino group, dodecylamino group , cyclopentylamino group, dicyclopentylamino group, cyclohexylamino group, dicyclohexylamino group, ditrifluoromethylamino group, phenylamino group, diphenylamino group, C ₁ ~ C ₁₂ alkoxyphenyl amino group, di (C ₁ C ₁₂ alkoxyphenyl) amino group, C ₁ ~ C ₁₂ alkyl phenyl group, di (C ₁ ~ C ₁₂ alkylphenyl) amino groups, 1-naphthylamino group, 2-naphthylamino group, pentafluorophenylamino group, pyridylamino Group, pyridazinylamino group, pyrimidylamino group, pyrazinylamino group, triazinylamino group, phenyl-C ₁ -C ₁₂ alkylamino group, C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkylamino group, di (C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkyl) amino group, C ₁ -C ₁₂ alkylphenyl-C ₁ -C ₁₂ alkylamino group, di (C ₁ -C ₁₂ alkylphenyl-C ₁ -C ₁₂ alkyl) amino groups, 1-naphthyl -C ₁ ~ C ₁₂ alkylamino groups, 2-naphthyl -C ₁ ~ C ₁₂ alkylamino groups and the like

The silyl group includes an unsubstituted silyl group and a silyl group substituted with 1, 2 or 3 substituents selected from alkyl groups, aryl groups, arylalkyl groups and monovalent heterocyclic groups (hereinafter referred to as substituted silyl groups). Means). The substituent may have a secondary substituent. The number of carbon atoms of the substituted silyl group is usually about 1 to 60, preferably about 3 to 48, more preferably about 3 to 40, not including the carbon number of the secondary substituent. Examples of the substituted silyl group include trimethylsilyl group, triethylsilyl group, tripropylsilyl group, tri-isopropylsilyl group, dimethyl-isopropylsilyl group, diethyl-isopropylsilyl group, tert-butyldimethylsilyl group, pentyldimethylsilyl group, Hexyldimethylsilyl group, heptyldimethylsilyl group, octyldimethylsilyl group, 2-ethylhexyl-dimethylsilyl group, nonyldimethylsilyl group, decyldimethylsilyl group, 3,7-dimethyloctyl-dimethylsilyl group, dodecyldimethylsilyl group, phenyl -C ₁ -C ₁₂ alkylsilyl group, C ₁ -C ₁₂ alkoxyphenyl -C ₁ -C ₁₂ alkylsilyl group, C ₁ -C ₁₂ alkylphenyl -C ₁ -C ₁₂ alkylsilyl group, 1-naphthyl-C ₁ ~ C ₁₂ Arukirushiri Group, 2-naphthyl -C ₁ ~ C ₁₂ alkylsilyl group, a phenyl -C ₁ ~ C ₁₂ alkyl dimethyl silyl group, a triphenylsilyl group, tri -p- Kishirirushiriru group, tribenzylsilyl group, diphenylmethylsilyl group, t -Butyldiphenylsilyl group, dimethylphenylsilyl group and the like.

Acyl group means an unsubstituted acyl group and an acyl group substituted with a halogen atom or the like. The carbon number of the acyl group is usually about 1 to 20, preferably about 2 to 18, and more preferably about 2 to 16. Examples of the acyl group include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, pivaloyl group, benzoyl group, trifluoroacetyl group, pentafluorobenzoyl group and the like.

Acyloxy group means an unsubstituted acyloxy group and an acyloxy group substituted with a halogen atom or the like. The carbon number of the acyloxy group is usually about 1 to 20, preferably about 2 to 18, and more preferably about 2 to 16. Examples of the acyloxy group include formyloxy group, acetoxy group, propionyloxy group, butyryloxy group, isobutyryloxy group, pivaloyloxy group, benzoyloxy group, trifluoroacetyloxy group, pentafluorobenzoyloxy group, and the like.

An imine residue means a residue obtained by removing one hydrogen atom in this structure from an imine compound having a structure represented by at least one of the formula: HN═C <and the formula: —N═CH—. To do. Examples of such imine compounds include compounds in which a hydrogen atom bonded to a nitrogen atom in aldimine, ketimine, and aldimine is substituted with an alkyl group, aryl group, arylalkyl group, arylalkenyl group, arylalkynyl group, or the like. It is done. The carbon number of the imine residue is usually about 2 to 20, preferably about 2 to 18, and more preferably about 2 to 16. Examples of the imine residue include a general formula: —CR′═N—R ″ or a general formula: —N═C (R ″) ₂ (wherein R ′ represents a hydrogen atom, an alkyl group, an aryl group, An arylalkyl group, an arylalkenyl group, and an arylalkynyl group, and R ″ each independently represents an alkyl group, an aryl group, an arylalkyl group, an arylalkenyl group, and an arylalkynyl group, provided that two R ″ When present, two R ″ are bonded to each other to form a divalent group such as an ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, etc. A ring may be formed as the alkylene group of). Specific examples of the imine residue include groups represented by the following structural formulas.

In the formula, Me represents a methyl group.

The amide group means an unsubstituted amide group and an amide group substituted with a halogen atom or the like. The carbon number of the amide group is usually about 2 to 20, preferably about 2 to 18, and more preferably about 2 to 16. Examples of the amide group include a formamide group, an acetamide group, a propioamide group, a butyroamide group, a benzamide group, a trifluoroacetamide group, a pentafluorobenzamide group, a diformamide group, a diacetamide group, a dipropioamide group, a dibutyroamide group, a dibenzamide group, Examples include a ditrifluoroacetamide group and a dipentafluorobenzamide group.

An acid imide group means a residue obtained by removing a hydrogen atom bonded to the nitrogen atom from an acid imide. The carbon number of the acid imide group is usually about 4 to 20, preferably about 4 to 18, and more preferably about 4 to 16. Examples of the acid imide group include the following groups.

In the formula, Me represents a methyl group.

The carboxyl group means an unsubstituted carboxyl group and a carboxyl group substituted with a substituent such as an alkyl group, an aryl group, an arylalkyl group, or a monovalent heterocyclic group (hereinafter referred to as a substituted carboxyl group). The substituent may have a secondary substituent. The carbon number of the substituted carboxyl group is usually about 1 to 60, preferably about 2 to 48, more preferably about 2 to 45, not including the carbon number of the secondary substituent. Examples of the substituted carboxyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, an isobutoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, and a pentyloxycarbonyl group. Hexyloxycarbonyl group, cyclohexyloxycarbonyl group, heptyloxycarbonyl group, octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, nonyloxycarbonyl group, decyloxycarbonyl group, 3,7-dimethyloctyloxycarbonyl group, dodecyloxy Carbonyl group, trifluoromethoxycarbonyl group, pentafluoroethoxycarbonyl group, perfluorobutoxycarbonyl group, perfluorohe Sill oxycarbonyl group, perfluorooctyl group, phenoxycarbonyl group, naphthoxycarbonyl group, pyridyloxycarbonyl group and the like.

Arylene group means an atomic group formed by removing two hydrogen atoms from an aromatic ring of an aromatic hydrocarbon, and includes those having an independent benzene ring or condensed ring. The arylene group generally has about 6 to 60 carbon atoms, preferably about 6 to 48, more preferably about 6 to 30, and further preferably 6 to 18. The number of carbon atoms does not include the number of carbon atoms of the substituent. Specific examples of the arylene group include unsubstituted or substituted phenylene groups such as 1,4-phenylene group, 1,3-phenylene group and 1,2-phenylene group; 1,4-naphthalenediyl group, 1,5- Unsubstituted or substituted naphthalenediyl groups such as naphthalenediyl group and 2,6-naphthalenediyl group; 1,4-anthracenediyl group, 1,5-anthracenediyl group, 2,6-anthracenediyl group, 9,10- Unsubstituted or substituted anthracenediyl group such as anthracenediyl group; unsubstituted or substituted phenanthrenediyl group such as 2,7-phenanthrenediyl group; 1,7-naphthacenediyl group, 2,8-naphthacenediyl group, 5,12- Unsubstituted or substituted naphthacenediyl group such as naphthacenediyl group; 2,7-fluorenediyl group, 3,6-fluorenediyl group, etc. Unsubstituted or substituted fluorenediyl group; unsubstituted or substituted pyrenediyl group such as 1,6-pyrenediyl group, 1,8-pyrenediyl group, 2,7-pyrenediyl group, 4,9-pyrenediyl group; -An unsubstituted or substituted perylenediyl group such as a perylenediyl group and a 3,10-perylenediyl group, and the like are preferable, and an unsubstituted or substituted phenylene group and an unsubstituted or substituted fluorenediyl group are preferable.

The divalent heterocyclic group usually has about 4 to 60 carbon atoms, preferably about 4 to 30 carbon atoms, and particularly preferably about 6 to 12 carbon atoms. The number of carbon atoms does not include the number of carbon atoms of the substituent. As the divalent heterocyclic group, a divalent aromatic heterocyclic group is preferable. Specific examples of the divalent heterocyclic ring include unsubstituted or substituted pyridinediyl groups such as 2,5-pyridinediyl group and 2,6-pyridinediyl group; unsubstituted or substituted such as 2,5-thiophenediyl group; A substituted thiophenediyl group; an unsubstituted or substituted furandyl group such as a 2,5-furandiyl group; an unsubstituted or substituted quinoline diyl group such as a 2,6-quinolinediyl group; a 1,4-isoquinolinediyl group; Unsubstituted or substituted isoquinoline diyl groups such as 5-isoquinoline diyl group; Unsubstituted or substituted quinoxaline diyl groups such as 5,8-quinoxaline diyl group; 4,7-benzo [1,2,5] thiadiazole diyl group An unsubstituted or substituted benzo [1,2,5] thiadiazolediyl group; an unsubstituted or substituted benzothiazolediyl group such as a 4,7-benzothiazolediyl group; 2 Unsubstituted or substituted carbazolediyl group such as 3,7-carbazolediyl group, 3,6-carbazolediyl group; Unsubstituted or substituted phenoxazinediyl group such as 3,7-phenoxazinediyl group; 3,7-phenothiazine An unsubstituted or substituted phenothiazinediyl group such as a diyl group; an unsubstituted or substituted dibenzosiloldiyl group such as a 2,7-dibenzosiloldiyl group; and the like, preferably an unsubstituted or substituted benzo [1,2 , 5] a thiadiazole diyl group, an unsubstituted or substituted phenoxazinediyl group, an unsubstituted or substituted phenothiazinediyl group.

<Organic EL device>
Examples of the laminated structure of the organic EL element of the present invention include the following. Furthermore, an electron block layer, a hole block layer, an electron injection layer, a hole injection layer, and the like may be stacked.

Anode / (organic layer containing polymer compound having repeating unit represented by formula (2)) / hole transport layer / light emitting layer / cathode Anode / (polymer having repeating unit represented by formula (2) Organic layer containing compound) / hole transport layer / light emitting layer / electron transport layer / cathode anode / (organic layer containing polymer compound having repeating unit represented by formula (2)) / light emitting layer / electron transport layer / Cathode (/ represents that the layers described on both sides of this symbol or layers and electrodes are laminated. Further, each layer may be a single layer or two or more layers.)

The hole transport layer usually contains a hole transport material, and the electron transport layer usually contains an electron transport material. These hole transport material and electron transport material may be either a high molecular compound or a low molecular compound, but a high molecular compound is preferable. Examples of the hole transport material and the electron transport material include polyfluorene and derivatives thereof, and copolymers containing fluorenediyl groups, polyarylene and derivatives thereof, and arylene groups described in the light-emitting materials described below. , A copolymer containing polyarylene vinylene and derivatives thereof, a copolymer containing an arylene vinylene group, an aromatic amine and derivatives thereof, and (co) polymers thereof.

As a hole transport material of a polymer compound, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives having an aromatic amine in the side chain or main chain, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polypyrrole And derivatives thereof, poly (2,5-thienylene vinylene), and derivatives thereof. Examples of the hole transport material of the low molecular weight compound include pyrazoline derivatives, arylamine derivatives, stilbene derivatives, and triphenyldiamine derivatives.

As the electron transport material used for the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane and derivatives thereof, benzoquinone and derivatives thereof, naphthoquinone and derivatives thereof, anthraquinones and derivatives thereof, tetra Cyanoanthraquinodimethane and its derivatives, fluorenone derivatives, diphenyldicyanoethylene and its derivatives, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and its derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives, polyfluorene and its derivatives, etc. Is exemplified. Specifically, JP-A 63-70257, 63-175860, JP 2-135359, 2-135361, 2-209988, 3-37992, Examples described in JP-A-3-152184 are exemplified.

Of these, oxadiazole derivatives, benzoquinone and its derivatives, anthraquinone and its derivatives, metal complexes of 8-hydroxyquinoline and its derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives, polyfluorene and its derivatives are preferred. More preferred are-(4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline.

The thickness of each layer included in the entire charge transport layer is appropriately selected so that the light emission efficiency and the drive voltage have desired values. The thickness of the hole transport layer is usually 1 to 300 nm. The thickness is preferably 5 to 100 nm. The thickness of the organic layer is usually 5 to 300 nm, preferably 30 to 200 nm, more preferably 40 to 150 nm. The thickness of the electron transport layer is usually 1 to 100 nm, preferably 1 to 40 nm.

In the organic EL device of the present invention, if at least one of the anode and the cathode is transparent or translucent, the generated light is transmitted, and thus the emission efficiency of light emission is favorable and convenient.

In the organic EL device of the present invention, an insulating layer (usually 10 nm or less in thickness) may be provided in contact with the cathode. Examples of the material for the insulating layer include metal fluorides, metal oxides, and organic insulating materials, and metal fluorides and metal oxides such as alkali metals or alkaline earth metals are preferable. A vacuum deposition method is exemplified as a method for forming the inorganic compound used for the insulating layer.

Furthermore, a protective layer for protecting the organic EL element may be mounted on the cathode. In order to use the organic EL element stably for a long period of time, it is preferable to attach a protective layer and / or protective cover to the element in order to protect the element from the outside.

As the material for the protective layer, polymer compounds, metal oxides, metal nitrides, metal nitride oxides, metal fluorides, metal borides and the like can be used. Further, as the protective cover, a glass plate, a plastic plate having a low water permeability treatment on the surface, or the like can be used. As a method of attaching the protective cover, the cover is attached to the element substrate with a thermosetting resin or a photocurable resin. A method of bonding and sealing is preferably used. If the space is maintained by using the spacer, it is easy to prevent the element from being damaged. If an inert gas such as nitrogen or argon is enclosed in the space, the cathode can be prevented from being oxidized. Further, a desiccant such as barium oxide or calcium oxide can be installed in the space in the manufacturing process. It becomes easy to prevent the adsorbed moisture from deteriorating the performance of the device. Among these, it is preferable to take any one or more measures.

FIG. 1 is a schematic cross-sectional view showing the structure of an organic EL element according to an embodiment of the present invention. This organic EL element includes an anode 2 formed on a substrate 1, a cathode 3, a light emitting layer 4 containing a light emitting material between the anode and the cathode, and an organic layer 5 between the anode and the light emitting layer. have. The anode 2 is formed of an electrode 6 and a coupling film 7 laminated on the surface thereof.

(Substrate 1)
The substrate 1 on which the organic EL element of the present invention is formed is not particularly limited as long as it does not change when the electrodes and each layer of the element are formed, and examples thereof include a glass, plastic, polymer film, silicon substrate, and the like. The In the case of an opaque substrate, the electrode on the opposite side to the electrode closer to the substrate is preferably transparent or translucent. Here, “transparent” means that the ratio (transmittance) of transmitted light intensity to incident light intensity when light having a wavelength of 750 to 400 nm passes through the electrode is 90 to 100%. Further, “translucent” means that the transmittance is 40% or more and less than 90%.

(Electrode 6)
As the electrode 6 used for forming the anode 2, a conductive material (NESA) made of indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide, or the like, which is a composite thereof, is used. Etc.), gold, platinum, silver, copper, etc. are used, and conductive inorganic oxides such as ITO, indium / zinc / oxide, and tin oxide are preferable. Further, as the anode, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used.

The film thickness of the electrode 6 can be appropriately selected in consideration of light transmittance and electrical conductivity. For example, it is 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm. It is.

Examples of the method for producing the electrode 6 include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method.

(Coupling film 7)
The coupling film 7 is a film containing a compound having both an atom or a group that interacts with the group on the surface of the electrode 6 and a material that has affinity with the material of the layer provided thereon such as the organic layer 5. is there. The presence of such a coupling film improves the adhesion at the interface between the electrode surface and the organic layer formed thereon, and facilitates the transfer of charges from the electrode to the organic layer.

Examples of the compound contained in the coupling film 7 include a coupling agent having a metal atom or metalloid atom and an organic group, such as a silane compound, a titanium compound, a germanium compound, a tin compound, an aluminum compound, an antimony compound, and bismuth. Compound, boron compound, cadmium compound, calcium compound, cerium compound, chromium compound, cobalt compound, copper compound, europium compound, gallium compound, indium compound, iridium compound, iron compound, lead compound, lithium compound, magnesium compound, manganese compound, A molybdenum compound, a nickel compound, a palladium compound, a silver compound, etc. are mentioned.

An example of such a preferable compound is a compound having a structure represented by the above formula (1). In formula (1), X is a monovalent organic group having a hetero atom, interacts with an atom or group present on the surface of the electrode, or a group formed by reacting X with another compound. Interacts with atoms or groups present on the surface of the electrode. The hetero atom contained in X is preferably a monovalent halogen atom or a hetero atom bonded to M ¹ . When the electrode is a metal, a metal oxide, or a metal sulfide, X is a hydroxyl group, a carboxyl group, an acyl group, an acyloxy group, a halocarbonyl group (formula: —C (O) —Y (formula Y represents a halogen atom), and a group represented by the formula: —C (O) —Cl and a group represented by the formula: —C (O) —Br are preferable. .), A halogen atom, an alkoxy group, an aryloxy group, an arylalkoxy group, a phosphoric acid group (a group represented by the formula (HO) ₂ P (O) —O—), a phosphoric acid ester group (the formula: (R ¹ O) ₂ P (O) —O— or the formula: (R ¹ O) (HO) P (O) —O— (wherein R ¹ represents an alkyl group, an aryl group, an arylalkyl group, an arylalkenyl group) , or an arylalkynyl group), a group represented by), phosphorous acid (formula:. (HO) ₂ Group) represented by -O-, phosphorous acid ester group (the ^{_{formula: (R 1 O) 2 P}} -O- or the ^{formula: (R 1 O) (HO} ) P-O- ( wherein, R ¹ is And a mercapto group, an alkylthio group, an arylthio group, an arylalkylthio group, a heterocyclic thio group, an amino group, and the like. Among these, X is preferably a halogen atom, an alkoxy group, a phosphoric acid group, an amino group or a hydroxyl group.

When X interacts with atoms or groups present on the surface of the electrode, a bond such as a covalent bond, a coordinate bond, an ionic bond, or a hydrogen bond is formed between the compound represented by formula (1) and the electrode. Presumed to be formed.

In addition, although the compound represented by Formula (1) may interact directly with the group or atom which exists in the surface of an electrode, X which this compound has reacts with another compound, it produced | generated by reaction. Groups may interact with groups or atoms present on the surface of the electrode. Examples of the reaction include a hydrolysis reaction with water.

The hydrolysis of the compound represented by the formula (1) refers to a phenomenon in which a part of the organic group X or X becomes a hydroxyl group by reaction with water. It is estimated that a bond such as a covalent bond, a coordinate bond, an ionic bond, or a hydrogen bond is formed between the hydroxyl group and the electrode by the interaction of the generated hydroxyl group with the atoms or groups present on the electrode surface. The In the step of forming an anode of the present invention, the compound represented by the formula (1) is preferably hydrolyzed because it is easily hydrolyzed to form a hydroxyl group to be easily bonded to the electrode. Examples of the organic group X that is susceptible to hydrolysis include an alkoxy group, an acetoxy group, a chlorine atom, and a phosphoric acid group. Further, the organic group X may contain an alkoxy group, an acetoxy group, a chlorine atom, a phosphoric acid group, or the like.

In formula (1), M ¹ represents an atom belonging to Group 4, Group 5, Group 6, Group 13, Group 14 or Group 15. M ¹ includes atoms belonging to Group 4 such as titanium atom, zirconium atom and hafnium atom; atoms belonging to Group 5 such as vanadium atom, niobium atom and tantalum atom; group 6 such as chromium atom, molybdenum atom and tungsten atom Atoms belonging to group 13 such as boron atom, aluminum atom, gallium atom, indium atom and thallium atom; atoms belonging to group 14 such as silicon atom, germanium atom, tin atom and lead atom; phosphorus atom, arsenic atom, Examples include atoms belonging to Group 15, such as antimony atoms and bismuth atoms. M ¹ is preferably a tin atom, a titanium atom, a zirconium atom, an aluminum atom, a niobium atom, a boron atom, a silicon atom, or a phosphorus atom. , Zirconium atom, aluminum atom, titanium atom, silicon atom or phosphorus atom More preferably, still more preferably titanium atom or a silicon atom, and particularly preferably a silicon atom.

In the formula (1), R ^a is a group showing affinity with the material of the layer provided thereon such as the organic layer 5. R ^a represents an alkyl group, an aryl group, an alkynyl group, an alkenyl group, an arylalkyl group, an arylalkenyl group or an arylalkynyl group, and is preferably an alkyl group, an aryl group or an arylalkyl group. The group represented by R ^a may have a substituent.

In formula (1), u represents the valence of M ¹ . For example, when M ¹ is a silicon atom, a titanium atom, a zirconium atom, or the like, u is 4, and when M ¹ is a boron atom, an aluminum atom, or the like, u is 3.

In the formula (1), v1 is an integer of 1 or more and u or less, preferably an integer of 2 or more, more preferably an integer of 3 or more.

Examples of the compound represented by the formula (1) include a compound represented by the formula (1-a).

In the formula, X ′ represents an alkoxy group, an acetoxy group, a chloro atom, or a phosphoric acid group. R ^{a ′} represents an alkyl group, an aryl group, an alkynyl group, an alkenyl group, an arylalkyl group, an arylalkenyl group, or an arylalkynyl group. The alkyl group may have an amino group as a substituent. The aryl group may have an amino group as a substituent. A plurality of X ′ may be the same or different.

Examples of the compound represented by the formula (1) include acetoxypropyltrichlorosilane, acetoxypropyltrimethoxysilane, adamantylethyltrichlorosilane, allyltrichlorosilane, allyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-amino Propyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltris (methoxyethoxyethoxy) silane, benzyltrichlorosilane, benzyltriethoxysilane, bis (trimethoxysilyl) ethane, 3-bromopropyltrichlorosilane, 3 -Bromopropyltriethoxysilane, 3-bromopropyltrimethoxysilane, 3-butenyltriethoxysilane, n-butyltrimethoxysilane, 2-chloroethyltrichloro Lan, 2-chloroethyltriethoxysilane, ((chloromethyl) phenylethyl) trimethoxysilane, (p-chloromethyl) phenyltrimethoxysilane, chlorophenyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyl Trimethoxysilane, (dichloromethyl) dimethylchlorosilane, (dichloromethyl) methyldichlorosilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, (3-glycidoxypropyl) trimethoxysilane, (3-glycol Sidoxypropyl) methyldimethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, 3-isocyanatopro Lutriethoxysilane, 3-mercaptopropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, methyltriethoxysilane, n-octadecyltrichlorosilane, n-octadecyltrichlorosilane, n-octyltriethoxysilane, pentafluoropropyltrichlorosilane, penta Fluoropropyltrimethoxysilane, phenethyltrimethoxysilane, phenoxytrichlorosilane, N-phenylaminopropyltrimethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, tetra-n-butoxysilane, tetraethoxysilane, 3-thiocyanate propyltri Ethoxysilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (tridecafluoro -1,1,2,2-tetrahydrooctyl) silane coupling agents such as methyldichlorosilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane; propyltrimethoxytitanium, octyltrimethoxytitanium, aminopropyltrimethoxy Titanium, aminodecyltrimethoxytitanium, mercaptopropyltrimethoxytitanium, mercaptooctyltrimethoxytitanium, aminopropyltriethoxytitanium, mercaptopropyltriethoxytitanium, mercaptodecyltriethoxytitanium, propyltrichlorotitanium, octyltrichlorotitanium, decyltrichlorotitanium, Aminopropyltrichlorotitanium, mercaptopropyltrichlorotitanium, mercaptooctyltrichlorotitanium, heptadecafluoro -1,1,2,2-tetrahydrodecyltriethoxytitanium, heptadecafluoro-1,1,2,2-tetrahydrodecyltrichlorotitanium, titanium ethoxide, titanium isobutoxide, titanium isopropoxide, titanium methoxide Titanium coupling agents such as: butylchlorodihydroxytin, butyltrichlorotin, diallyldibutyltin, dibutyldiacetoxytin, dibutyldichlorotin, dibutyldibromotin, dibutyldimethoxytin, dimethyldichlorotin, dioctyldichlorotin, diphenyldichlorotin, methyltrichloro Tin, phenyltrichlorotin, aluminum ethoxide, aluminum isopropoxide, aluminum butoxide, tetrabutoxygermane, tetraethoxygermane, tetramethoxygen Man, hafnium butoxide, hafnium ethoxide, indium methoxy ethoxide, niobium butoxide, niobium ethoxide, zirconium butoxide, zirconium ethoxide, zirconium propoxide and the like.

In addition, the compound represented by Formula (1) may be used individually by 1 type, or may use 2 or more types together.

As a method for forming the anode 2 used in the present invention, the compound represented by the formula (1) is dissolved or dispersed in a solvent, and the electrode 6 is immersed in the obtained solution to form atoms present on the surface of the electrode. Alternatively, a group and a group represented by X in the compound are allowed to interact to form a coupling film 7, or the compound is dissolved or dispersed in a solvent, and the obtained solution is applied to the electrode by an appropriate method. A method of forming the coupling film 7 by printing or coating is mentioned.

Solvents for dissolving or dispersing the compound include chlorine solvents such as chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, o-dichlorobenzene; ether solvents such as tetrahydrofuran and dioxane. Aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane Ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, etc .; ester solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate; ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol Polyhydric alcohols such as methyl ether, dimethoxyethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, 1,2-hexanediol and derivatives thereof; alcohols such as methanol, ethanol, propanol, isopropanol, cyclohexanol Examples of the solvent include sulfoxide solvents such as dimethyl sulfoxide; water and the like. In addition, the said solvent may be used individually by 1 type, or may use 2 or more types together.

When the immersion method is used, the concentration of the compound in a solution obtained by dissolving or dispersing the compound represented by the formula (1) in a solvent is preferably 0.01 to 100 mmol / l. If the concentration is too low, the reaction between the compound and the electrode may be required for a long time. On the other hand, if the concentration is too high, the film formability may be reduced due to aggregation of the compound. When the printing method is used, the concentration of the compound is preferably 0.001 to 10 mmol / l. If the concentration is too low, it may be difficult to obtain a uniform thin film. If the concentration is too high, it may be difficult to inject charges because a thick film is formed.

The average film thickness of a film formed by printing or dipping using a solution containing the compound represented by formula (1) and a solvent is preferably 0.1 to 30 nm from the viewpoint of charge injection / transport properties. More preferably, it is 1.0 to 20 nm, and further preferably 1.0 to 10 nm. When the average film thickness of the film is large, charge injection from the electrode to the light emitting layer may not be performed sufficiently, and the drive voltage may increase or the durability may decrease.

As the printing method, a spin coating method, a micro gravure coating method, a gravure coating method, a screen printing method, a flexographic printing method, an offset printing method, or the like can be used. Since the concentration of the solution for forming a thin film having an appropriate thickness varies depending on the coating method, it is necessary to adjust appropriately.

(surface treatment)
Next, the surface treatment will be described. The surface of the coupling film 7 is subjected to a surface treatment before a layer, for example, the organic layer 5 is provided thereon. Here, the surface treatment includes plasma treatment, corona discharge treatment, UV ozone treatment and the like, and UV ozone treatment is preferable. By performing the surface treatment, when the organic layer is formed on the coupling film 7 by using a coating method, the wettability with respect to the solution is improved, and the organic layer can be formed with a uniform film thickness. When UV ozone treatment is performed, wettability can be improved by oxidizing the coupling agent present on the surface of the coupling film 7. Further, the energy level of the highest occupied orbit (HOMO) of the anode including the coupling film subjected to the UV ozone treatment is close to the HOMO energy level of the organic layer 5, and there is a barrier for holes to move to the organic layer. Can be low.

Further, it is preferable that the surface of the electrode 6 is also subjected to UV ozone treatment before the coupling film 7 is provided thereon. This is because organic substances present on the surface of the electrode 6 are removed, and the interaction between atoms or groups present on the surface and the group X in the formula (1) is strengthened.

“UV ozone treatment” means that an article is irradiated with ultraviolet rays (UV) in the presence of oxygen. Oxygen in the air is changed to ozone, and the film is modified by the ozone and ultraviolet rays. The UV light source only needs to change oxygen into ozone by UV irradiation.

Examples of the UV light source include a low-pressure mercury lamp. Low pressure mercury lamps generate UV light at 185 nm and 254 nm, and the 185 nm line can convert oxygen to ozone. Due to the strong oxidizing power generated by the synergistic effect of UV and ozone, the surface of the electrode can be modified and charge injection can be promoted. The illuminance at the time of irradiation varies depending on the light source used, but a light source of several tens to several hundreds mW / cm ² is generally used. Moreover, illumination intensity can be changed by condensing or diffusing. The irradiation time varies depending on the illuminance of the lamp and the type of the non-treated layer, but is usually 1 minute to 24 hours. The treatment temperature is usually 10 to 200 ° C. The irradiation amount of UV (i.e., the amount of ultraviolet) (J / cm ²⁾ is usually at 1 J / cm ² or more, preferably 1 ~ 100000J / cm ^2, more preferably 10 ~ 100000J / cm ² More preferably, it is 100 to 100,000 J / cm ² , and particularly preferably 1000 to 100,000 J / cm ² .

(Organic layer 5)
In the organic EL element of the present invention, the organic layer 5 is provided between the anode 2 and the light emitting layer 4. The organic layer 5 contains a polymer compound having a repeating unit represented by the above formula (2). In this repeating unit structure, the arylamine is cross-linked through Y ₁ , so that the planarity of the polymer compound is increased, the interaction between the molecular chains of the polymer compound is likely to occur, and holes are emitted. Easy to transport to the layer.

R ^b in formula (2) is preferably an alkyl group, an aryl group, an arylalkyl group, an alkenyl group, an alkynyl group, an acyl group, a monovalent heterocyclic group, or a substituted carboxyl group, more preferably , An alkyl group, and an aryl group. In addition, Y ₁ in the formula (2) is preferably —O—.

In addition, the repeating unit represented by the formula (2) has a bond on each of the A ring and the B ring. A ring and B ring are the same or different, and represent a monocyclic aromatic ring or a condensed aromatic ring. Moreover, A ring and B ring may each have a substituent.

Examples of such aromatic rings include aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, perylene ring, tetracene ring, pentacene ring, fluorene ring; pyridine ring, pyrimidine ring, Pyridazine ring, pyrazine ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, acridine ring, phenanthroline ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, thiophene oxide ring, benzothiophene oxide ring, dibenzothiophene oxide ring, furan Aromatic heterocycles such as a ring, a benzofuran ring, a pyrrole ring, an indole ring, a dibenzopyrrole ring, a silole ring, a benzosilole ring, a dibenzosilole ring, a borol ring, a benzoborol ring, and a dibenzoborol ring are exemplified. Among these, from the viewpoint of the heat resistance of the polymer compound and the device characteristics of the organic EL device produced using the polymer compound, an aromatic hydrocarbon ring is preferable, and a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring. Is more preferable, and a benzene ring is particularly preferable.

Examples of the substituent that the A ring and the B ring may have include, for example, a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, and an arylalkoxy group. An arylalkylthio group, an alkenyl group, an alkynyl group, a substituted amino group substituted with two substituents, a substituted silyl group substituted with three substituents, an acyl group, an acyloxy group, an imine residue, an amide group, Examples include an acid imide group, a monovalent heterocyclic group, and a substituted carboxyl group.

Preferred examples of the repeating unit represented by the formula (2) include a repeating unit represented by the formula (3).

In the formula, Y ¹ and R ^b represent the same meaning as described above.

Specific examples of the repeating unit represented by the general formula (3) include the following repeating units.

In the organic EL device of the present invention, the difference between the energy level of the highest occupied orbit (HOMO) of the anode and the energy level of the HOMO of the polymer compound having the repeating unit represented by the formula (2) is as small as possible. preferable. This difference in energy level represents an energy barrier when holes are injected from the anode into the polymer compound having the repeating unit represented by the formula (2). When this is small, holes are transferred from the anode to the formula (2 This is because it can be easily injected into a polymer compound having a repeating unit represented by: Specifically, the difference in energy ranking is preferably 0.5 eV or less, and more preferably 0.3 eV or less.

The film thickness of the organic layer containing the polymer compound having the repeating unit represented by the formula (2) is preferably 10 nm or more and 500 nm or less, more preferably 20 nm or more and 300 nm from the viewpoint of device durability and current characteristics. It is below, More preferably, they are 30 nm or more and 200 nm or less.

In addition to the repeating unit represented by the formula (2), the polymer compound containing the repeating unit represented by the formula (2) includes an arylene group, an arylene vinylene group, a divalent heterocyclic group, a divalent heterocyclic group as a repeating unit. An aromatic amine residue may be included. Among the above groups, an arylene group and a divalent aromatic amine residue are preferable. Among the arylene groups, 1,4-phenylene group, 2,7-fluorenediyl group, 3,6-fluorenediyl group An unsubstituted or substituted fluorenediyl group such as a group is more preferable.

For example, a preferred fluorenediyl group structure has the formula

[In the formula, each R ^c independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an arylalkyl group, an arylalkoxy group, an arylalkenyl group, an arylalkynyl group, an amino group, a substituted amino group, or a halogen atom. Represents an acyl group, an acyloxy group, a monovalent heterocyclic group, or a carboxyl group. Moreover, the said substituent may have a crosslinkable group further. ]

It is represented by In a preferred embodiment, in Formula (6), each R ^c independently represents an alkyl group, an aryl group, or an arylalkyl group, and more preferably represents a linear alkyl group.

When the fluorenediyl group is contained in the polymer compound, the effect of excellent hole transportability can be obtained.

In addition, the structure of a preferred divalent aromatic amine residue has the formula

[Wherein, R ^d and R ^e each independently represents an alkyl group or an aryl group, x represents an integer of 0 to 5, and y represents an integer of 0 to 5. When a plurality of R ^d or R ^e are present, each R ^d or R ^e may be the same or different. a represents 0 or 1; Moreover, the said substituent may have a crosslinkable group further. ]

When the above-mentioned polymer compound contains the above-mentioned divalent aromatic amine residue, the hole transportability may be better than when the compound represented by formula (2) is used alone.

The amount of the repeating unit represented by the formula (2) contained in the polymer compound is preferably 3 mol% or more and 100 mol% or less when the amount of the repeating unit contained in the polymer compound is 100 mol%. More preferably, they are 5 mol% or more and 100 mol% or less, More preferably, they are 10 mol% or more and 100 mol% or less, Especially preferably, they are 30 mol% or more and 100 mol% or less.

An organic layer containing a polymer compound containing a repeating unit represented by the formula (2) may be used as a hole transport layer. In that case, the hole transport layer may contain another hole transport material in addition to the polymer compound. The hole transport material may be a high molecular compound or a low molecular compound, but a high molecular compound is preferable. For example, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives having an aromatic amine in the side chain or main chain, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polypyrrole and derivatives thereof, poly (2,5-thieni Lembinylene) and derivatives thereof. Examples of the hole transport material of the low molecular weight compound include pyrazoline derivatives, arylamine derivatives, stilbene derivatives, and triphenyldiamine derivatives.

The polymer compound containing the repeating unit represented by the formula (2) preferably has a polystyrene-equivalent number average molecular weight of 10 ³ to 10 ⁸ , more preferably 10 ⁴ to 10 ⁶ .

Examples of a method for synthesizing a polymer compound having a repeating unit represented by the formula (2) in the main chain include a method of polymerizing monomers according to a repeating unit of a desired polymer compound by a Suzuki coupling reaction, Grignard Polymerization by reaction, polymerization with Ni (0) catalyst, polymerization with an oxidizing agent such as FeCl ₃ , electrochemical oxidative polymerization, decomposition of intermediate polymer compound with appropriate leaving group Methods and the like. Among these, a method of polymerizing by Suzuki coupling reaction, a method of polymerizing by Grignard reaction, and a method of polymerizing by Ni (0) catalyst are preferable in terms of easy reaction control.

In the above reaction, an alkali and an appropriate catalyst can be appropriately added to promote the reaction. These alkalis and appropriate catalysts may be selected according to the type of reaction, but those that are sufficiently soluble in the solvent used in the reaction are preferred. Examples of the alkali include inorganic bases such as potassium carbonate and sodium carbonate; organic bases such as triethylamine and tetraethylammonium hydroxide; inorganic salts such as cesium fluoride. Examples of the catalyst include tetrakis (triphenylphosphine) palladium and palladium acetates.

Since the purity of the polymer compound containing the repeating unit represented by formula (2) in the main chain affects the light emitting characteristics of the device, the monomer before polymerization is purified by methods such as distillation, sublimation purification, and recrystallization. After the synthesis, it is preferably polymerized, and after the synthesis, it is preferable to carry out a purification treatment such as reprecipitation purification and fractionation by chromatography.

Examples of the solvent used in the reaction include saturated hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene; carbon tetrachloride, chloroform, dichloromethane, chlorobutane, Halogenated saturated hydrocarbons such as bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane and bromocyclohexane; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and trichlorobenzene; methanol, ethanol, propanol and isopropanol Alcohols such as butanol and tert-butyl alcohol; carboxylic acids such as formic acid, acetic acid and propionic acid; dimethyl ether, diethyl ether, methyl-t rt- butyl ether, tetrahydrofuran, tetrahydropyran, dioxane and the like; hydrochloric acid, hydrobromic acid, hydrofluoric acid, sulfuric acid, and the like inorganic acids such as nitric acid is. These solvents may be used alone or in combination of two or more.

After the reaction, for example, a crude polymer compound can be obtained by usual post-treatment such as adding water to stop the reaction, extracting with an organic solvent, and distilling off the organic solvent. In addition, as described above, the isolation and purification of the polymer compound can be performed by a method such as fractionation by chromatography, recrystallization and the like.

Specific examples of the method for synthesizing the polymer compound having the repeating unit represented by the formula (3) include the compound represented by the formula (4) alone or the compound represented by the formula (4) and the formula Examples thereof include a method of polymerizing the compound represented by (5) by the above method.

In formulas (4) and (5), Y ¹ and R ^b represent the same meaning as described above, Ar ¹ represents an arylene group, a divalent heterocyclic group or a divalent aromatic amine residue, and Z ¹ To Z ⁴ are the same or different and are a halogen atom, alkylsulfonyloxy group, arylsulfonyloxy group, arylalkylsulfonyloxy group, boric acid ester residue, sulfonium methyl group, phosphonium methyl group, phosphonate methyl group, monohalogenated It represents a methyl group, a boric acid residue (—B (OH) ₂ ), a formyl group or a vinyl group.

In a preferred embodiment, Ar ¹ is a fluorenediyl group represented by formula (6) or a divalent aromatic amine residue represented by formula (7). Both of these two types of compounds represented by formula (5) may be polymerized together with the compound represented by formula (4).

From the viewpoint of synthesis of the compound represented by the formula (4) or the compound represented by the formula (5) and the viewpoint of easy reaction, Z ¹ to Z ⁴ are the same or different and are each a halogen atom, It is preferably an alkylsulfonyloxy group, an arylsulfonyloxy group, an arylalkylsulfonyloxy group, a boric acid ester residue or a boric acid residue.

Examples of the alkylsulfonyloxy group include a methanesulfonyloxy group, an ethanesulfonyloxy group, a trifluoromethanesulfonyloxy group, and the like. Examples of the arylsulfonyloxy group include a benzenesulfonyloxy group and a p-toluenesulfonyloxy group. Examples of the arylalkylsulfonyloxy group include a benzylsulfonyloxy group.

Examples of the boric acid ester residue include a group represented by the following formula.

In the formula, Me represents a methyl group, and Et represents an ethyl group.

Examples of the sulfonium methyl group include groups represented by the following formula.

In the formula, α represents a halogen atom, Me represents a methyl group, and Ph represents a phenyl group.

Examples of the phosphonium methyl group include groups represented by the following formula.

In the formula, α represents a halogen atom, and Ph represents a phenyl group.

Examples of the phosphonate methyl group include groups represented by the following formula.

In the formula, R ¹¹ represents an alkyl group, an aryl group, or an arylalkyl group.

Examples of the monohalogenated methyl group include a methyl fluoride group, a methyl chloride group, a methyl bromide group, and a methyl iodide group.

In addition, when another layer, for example, a light emitting layer is laminated on an organic layer containing a polymer compound containing a repeating unit represented by the formula (2) in the main chain, the two layers are mixed or mixed in the organic layer. In order to prevent the elution of the compound, it is preferable to insolubilize the organic layer. For insolubilization treatment, a soluble polymer precursor is used to convert the polymer precursor to a conjugated polymer compound by heat treatment, and the substituent is decomposed using a polymer compound having a soluble substituent. Treatment to lower solubility, polymer compound having a crosslinkable group in the molecule, treatment to crosslink with heat, light, electron beam, etc., monomer that causes crosslinking reaction with heat, light, electron beam, etc. Examples of the treatment for crosslinking are shown below. In particular, it is preferable to use a polymer compound having a crosslinkable group in the molecule.

Examples of the polymer compound having the repeating unit represented by the formula (2) in the main chain having the crosslinkable group in the molecule include the polymer compound having a crosslinkable group in the side chain. Examples of such a crosslinkable group include a vinyl group, an acetylene group, a butenyl group, a group having an acrylic structure, a group having an acrylate structure, a group having an acrylamide structure, a group having a methacrylic structure, a group having a methacrylate structure, A group having a methacrylamide structure, a group having a vinyl ether structure, a group having a vinylamino structure, a silanol group, a small ring (eg, cyclopropyl ring, cyclobutyl ring, epoxy ring, oxetane ring, diketene ring, episulfide ring, etc.) A group having a lactone structure, a group having a lactam structure, a group containing a siloxane bond, and the like. In addition to these groups, combinations of groups capable of forming an ester bond or an amide bond can be used. For example, a combination of a group having an ester structure and an amino group, a group having an ester structure and a hydroxyl group, or the like. Furthermore, the group etc. which contain the benzocyclobutane structure of WO97 / 09394 published specification are illustrated. Among these, a group having an acrylate structure, a group having a methacrylate structure, and a group having a benzocyclobutane structure are particularly preferable.

Specific examples of the monofunctional monomer having a group having an acrylate structure or a group having a methacrylate structure include 2-ethylhexyl carbitol acrylate and 2-hydroxyethyl acrylate. Specific examples of the bifunctional monomer having a group having an acrylate structure or a group having a methacrylate structure include 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, Examples thereof include neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, 3-methylpentanediol diacrylate, and 3-methylpentanediol dimethacrylate. Specific examples of other polyfunctional monomers having a group having an acrylate structure or a group having a methacrylate structure include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate Pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate and the like.

In the polymer compound containing the repeating unit represented by the formula (2) in the main chain having the crosslinkable group in the molecule, the content of the crosslinkable group is usually such that the repeating unit having the crosslinkable group is completely repeated. The amount is 0.01 to 30 mol%, preferably 0.5 to 25 mol%, more preferably 1 to 20 mol%, based on the unit.

Examples of the monomer that causes a crosslinking reaction include monomers having a polystyrene-equivalent weight average molecular weight of 2000 or less and having two or more of the above crosslinkable groups. Examples of the crosslinking reaction of the polymer compound having a crosslinkable group or a monomer that causes a crosslinking reaction include reactions that occur by heating, irradiation with light, electron beam, or the like. The reaction may be performed in the presence of a thermal polymerization initiator, a photopolymerization initiator, a thermal polymerization initiation assistant, a photopolymerization initiation assistant, or the like.

In the case of insolubilization by heating, the heating temperature may be lower than the temperature at which the characteristics deteriorate due to the decomposition of the material, but is, for example, 50 to 300 ° C, preferably 100 to 250 ° C.

When insolubilized by heating, as a thermal polymerization initiator that can be used in combination, a compound generally known as a radical polymerization initiator can be used. For example, 2,2′-azobisisobutyronitrile, 2,2 Azo compounds such as' -azobis- (2,4-dimethylvaleronitrile) and 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, tert-butylperoxypivalate , Organic peroxides such as 1,1′-bis (tert-butylperoxy) cyclohexane, and hydrogen peroxide.

When a peroxide is used as the radical polymerization initiator, the peroxide may be used together with a reducing agent to form a redox initiator. Each of these thermal polymerization initiators can be used alone or in combination of two or more. The reaction temperature when the thermal polymerization initiator is used in combination is, for example, 40 to 250 ° C., preferably 50 to 200 ° C. In photopolymerization using a photopolymerization initiator, ultraviolet rays may be irradiated at an irradiation intensity of 0.01 mW / cm ² or more for 1 second to 3600 seconds, preferably 30 seconds to 600 seconds.

Examples of the photopolymerization initiator include an active radical generator that generates an active radical when irradiated with light, and an acid generator that generates an acid. Examples of the active radical generator include an acetophenone photopolymerization initiator, a benzoin photopolymerization initiator, a benzophenone photopolymerization initiator, a thioxanthone photopolymerization initiator, and a triazine photopolymerization initiator. These photopolymerization initiators can be used alone or in combination of two or more.

Examples of the method for forming the organic layer include a method of forming a film from a solution. For film formation from a solution, for example, a printing method such as a screen printing method, a flexographic printing method, an offset printing method, an ink jet printing method, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method. Application methods such as roll coating, wire bar coating, dip coating, spray coating, nozzle coating, and capillary coating can be used. Among these, printing methods such as a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method are preferable in that pattern formation and multicolor coating are easy.

Ink is usually used for the method of forming a film from the above solution. This ink comprises a material constituting each layer (in the case of an organic layer, a polymer compound containing a repeating unit represented by formula (2)) and a solvent. The solvent is not particularly limited, but a solvent that can dissolve or uniformly disperse components other than the solvent constituting the ink is preferable. Examples of the solvent include chlorine solvents such as chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene and o-dichlorobenzene; ether solvents such as tetrahydrofuran and dioxane; toluene, xylene and the like. Aromatic hydrocarbon solvents; cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane and other aliphatic hydrocarbon solvents; acetone, methyl ethyl ketone, cyclohexanone Ketone solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, etc .; ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxy Polyhydric alcohols and derivatives thereof such as tan, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, 1,2-hexanediol; alcohol solvents such as methanol, ethanol, propanol, isopropanol, cyclohexanol; dimethyl Examples include sulfoxide solvents such as sulfoxide; amide solvents such as N-methyl-2-pyrrolidone and N, N-dimethylformamide. In addition, the said solvent may be used individually by 1 type, or may use 2 or more types together.

The ratio of the solvent in the ink is 1% to 99.9% by weight, preferably 60% to 99.5% by weight, more preferably 80% to 99.0%, based on the solute. % By weight.

The viscosity of the ink varies depending on the printing method to be applied. However, in the case where the ink passes through the ejection device, such as an ink jet printing method, the viscosity is 25 ° C. in order to prevent clogging and flight bending during ejection. It is preferably in the range of 1 to 20 mPa · s.

The thickness of the organic layer is appropriately selected so that the light emission efficiency and the driving voltage have desired values, but is usually 1 to 300 nm, preferably 5 to 50 nm.

(Light emitting layer 4)
The light emitting layer 4 included in the organic EL device of the present invention can be obtained by, for example, co-evaporation of a light emitting material or the like, or film formation from a solution containing the light emitting material and a solvent. In addition, the said luminescent material may be used individually by 1 type, or may use 2 or more types together.

Examples of the light-emitting material include “organic EL display” (Co-authored by Shizuo Tokito, Chiya Adachi, Hideyuki Murata, published by Ohm Co., Ltd., 2004, first edition, first print) 17-48 pages, 83-99 pages, 101-120 The fluorescent material or triplet light-emitting material described on the page can be used. Examples of low-molecular fluorescent materials include naphthalene derivatives, anthracene and derivatives thereof, perylene and derivatives thereof, polymethine-based, xanthene-based, coumarin-based, cyanine-based pigments, 8-hydroxyquinoline metal complexes, 8-hydroxy Examples include metal complexes of quinoline derivatives, aromatic amines, tetraphenylcyclopentadiene and derivatives thereof, tetraphenylbutadiene and derivatives thereof, and more specifically, JP-A-57-51781 and JP-A-59-194393. The thing etc. which are described in gazette gazette can be used. In addition, examples of the light emitting material include, for example, WO99 / 13692 published specification, WO99 / 48160 published specification, GB2340304A, WO00 / 53656 published specification, WO01 / 19834 published specification, WO00 / 55927 published specification, GB2348316, WO00 / 46321 published specification, WO00 / 06665 published specification, WO99 / 54943 published specification, WO99 / 54385 published specification, US5777070, WO98 / 06773 published specification, WO97 / 05184 published specification, WO00 / 35987 published Specification, WO00 / 53655 publication specification, WO01 / 34722 publication specification, WO99 / 24526 publication specification, WO00 / 22027 publication specification, WO00 / 22026 publication specification, WO98 / 271 6 published specifications, US573636, WO98 / 21262 published specifications, US5741921, WO97 / 09394 published specifications, WO96 / 29356 published specifications, WO96 / 10617 published specifications, EP0707020, WO95 / 07955 published specifications, JP2001-2001 No. 18618, No. 2001-123156, No. 2001-3045, No. 2000-351967, No. 2000-303066, No. 2000-299189, No. 2000-252065. JP, 2000-136379, JP 2000-104057, JP 2000-80167, JP 10-324870, JP 10-114891, JP 9-111233, JP Of polyfluorenes, derivatives and copolymers thereof, polyarylenes, derivatives and copolymers thereof, polyarylene vinylenes, derivatives and copolymers thereof, aromatic amines and derivatives thereof disclosed in JP-A-9-45478 Co) polymers are exemplified.

Examples of the triplet light emitting material include Ir (ppy) ₃ , Btp ₂ Ir (acac) having iridium as a central metal, PtOEP having platinum as a central metal, Eu (TTA) ₃ phen having a central metal as europium, etc. And the triplet light-emitting complex.

Examples of the triplet light emitting complex include Nature, (1998), 395, 151, Appl. Phys. Lett. 1999 (1999), 75 (1), 4, Proc. SPIE-Int. Soc. Opt. Eng. 2001), 4105 (Organic-Light-Emitting Materials and Devices IV), 119, J. Am. Chem. Soc., (2001), 123, 4304, Appl. Phys. Lett., (1997), 71 (18), 2596 , Adv. Mater., (1999), 11 (10), 852App, Jpn. J. Appl. Phys., 34, 1883 (1995), and the like.

The light emitting material may be a high molecular compound, for example, any of an alternating copolymer, a random polymer, a block polymer, and a graft copolymer, and has an intermediate structure thereof. It may be a high molecular compound, for example, a random copolymer having a block property. The light-emitting material exhibits high charge transport performance, and from the viewpoint of high luminous efficiency, low driving voltage, and long life, the random copolymer and block copolymer having a block property from a completely random copolymer. Polymers and graft copolymers are preferred. Note that the light-emitting material includes a polymer compound having a branched main chain and three or more terminal portions, and a so-called dendrimer.

(Cathode 3)
The cathode 3 is usually transparent or translucent. As such a cathode material, a material having a small work function is preferable, for example, alkaline metals such as lithium, sodium, potassium, rubidium and cesium, alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium, aluminum , Scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and other metals, and two or more alloys thereof, or one or more thereof, and gold, silver, platinum An alloy with one or more of copper, manganese, titanium, cobalt, nickel, tungsten, tin, graphite, a graphite intercalation compound, and the like are used. Examples of the alloy include a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy. The cathode may be a single layer or two or more layers. Moreover, the material of the said cathode may be used individually by 1 type, or may use 2 or more types together.

The thickness of the cathode 3 can be appropriately adjusted in consideration of electric conductivity and durability, but is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm. .

For the production of the cathode 3, a method such as a vacuum deposition method, a sputtering method, a laminating method in which a metal thin film is thermocompression bonded is used. Further, a layer made of a conductive polymer compound, a layer made of a metal oxide, a metal fluoride, an organic insulating material, or the like may be provided.

<Application>
The organic EL element of the present invention can be used as a planar light source, a display device (for example, a segment display device or a dot matrix display device), a backlight of a liquid crystal display device, or the like.

In order to obtain planar light emission using the organic EL element of the present invention, the planar anode and cathode may be arranged so as to overlap each other. In addition, in order to obtain pattern-like light emission, a method of installing a mask having a pattern-like window on the surface of the planar light-emitting element, a non-light-emitting portion layer is formed extremely thick and substantially non-light-emitting. And a method of forming either or both of the anode and the cathode in a pattern. By forming a pattern by any one of these methods and arranging several electrodes so that they can be turned on and off independently, a segment type display element capable of displaying numbers, letters, simple symbols and the like can be obtained.

Furthermore, in order to obtain a dot matrix element, both the anode and the cathode may be formed in stripes and arranged so as to be orthogonal. Partial color display and multicolor display are possible by a method of separately coating a plurality of types of polymers having different emission colors or a method using a color filter or a fluorescence conversion filter. The dot matrix element may be either passive drive or active drive combined with a thin film transistor using amorphous silicon or low-temperature polysilicon. These display elements can be used in display devices such as computers, televisions, mobile terminals, mobile phones, car navigation systems, video camera viewfinders, and the like.

The planar light-emitting element is a self-luminous thin type and can be suitably used as a planar light source for a backlight of a liquid crystal display device and a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source or display device.

Hereinafter, examples and comparative examples will be shown to describe the present invention in more detail, but the present invention is not limited to these examples.

The number average molecular weight and weight average molecular weight in terms of polystyrene of the polymer compound for GPC measurement were determined by size exclusion chromatography (SEC) (“LC-10Avp” manufactured by Shimadzu Corporation). The polymer compound to be measured was dissolved in tetrahydrofuran to a concentration of about 0.05% by weight, and 10 μL was injected into SEC. Tetrahydrofuran was used as the mobile phase of SEC and was allowed to flow at a flow rate of 2.0 mL / min. As the column, “PLgel MIXED-B” manufactured by Polymer Laboratories was used. A UV-VIS detector (“SPD-10Avp” manufactured by Shimadzu Corporation) was used as the detector.

Synthesis example 1
Synthesis of Polymer Compound A Synthesis of the following structural formula, N, N-bis (4-bromophenyl) -N- (1,2-dihydrobenzocyclobutan-4-yl) -amine is described in Examples in Japanese Translation of PCT International Publication No. 2007-511636. 1 was synthesized. That is, diphenylamine and 1,2-dihydro-4-bromobenzocyclobutane were reacted to obtain diphenylbenzocyclobutaneamine. Subsequently, diphenylbenzocyclobutanamine and N-bromosuccinimide were reacted to obtain N, N-bis (4-bromophenyl) -N- (1,2-dihydrobenzocyclobutan-4-yl) -amine.

Into the reactor substituted with inert gas, 2,7-bis (1,3,2-dioxaborolan-2-yl) -9,9-dioctylfluorene (18 g), N, N-bis (4-bromophenyl) -N— ( 4-sec-Butylphenyl) -amine 13 g, N, N-bis (4-bromophenyl) -N- (1,2-dihydrobenzocyclobutan-4-yl) -amine 2 g, methyltrioctylammonium chloride (trade name) : A1iquat336 (registered trademark), manufactured by Aldrich) 3 g and toluene 200 g were weighed. The reaction vessel was heated to 100 ° C., 7.4 mg of palladium (II) acetate, 70 mg of tri (o-tolyl) phosphine, and 64 g of an about 18% aqueous sodium carbonate solution were added, and the stirring was continued for 5 hours. Thereafter, 400 mg of phenylboronic acid was added, and heating and stirring were further continued for 5 hours. The reaction solution was diluted with 190 g of toluene, washed twice with 60 g of a 3% aqueous acetic acid solution and once with 60 g of ion-exchanged water, and then 1.5 g of DDC (sodium diethyldithiocarbamate trihydrate) was added to the extracted organic phase. Stir for 4 hours. The solution was purified by column chromatography using an equal volume mixture of alumina and silica gel as the stationary phase. The obtained toluene solution was dropped into methanol and stirred, and then the resulting precipitate was collected by filtration and dried. The number average molecular weight of polystyrene conversion of the high molecular compound A was 8.9 * 10 < ⁴ >, and the weight average molecular weight of polystyrene conversion was 4.2 * 10 < ⁵ >.

Polymer compound A has the following repeating units. Here, the number attached with () indicates the mol% of the repeating unit.

Synthesis example 2
Synthesis of polymer compound B 3,7-dibromo-N-hexylphenoxazine was used instead of N, N-bis (4-bromophenyl) -N- (4-sec-butylphenyl) -amine in Synthesis Example 1 Thus, a polymer compound B represented by the following was synthesized. The polymer compound had a polystyrene-equivalent number average molecular weight of 6.0 × 10 ⁴ and a polystyrene-equivalent weight average molecular weight of 2.3 × 10 ⁵ .

Polymer compound B has the following repeating units. Here, the number attached with () indicates the mol% of the repeating unit.

Example 1
Preparation of Organic EL Element 1 A transparent electrode was prepared by attaching an ITO film with a thickness of 150 nm on the surface of a glass substrate by sputtering. This electrode surface was irradiated for 20 minutes using a UV ozone apparatus (“Model 312 UV-O3 cleaning system” manufactured by Technovision). Next, a solution obtained by dissolving 3-aminopropyltriethoxysilane in a mixed solvent of ethanol / water = 95/5 (weight ratio) at a concentration of 0.10% by weight is spin-coated at a rotational speed of 2000 rpm. A thin film was formed on the electrode. Thereafter, the substrate on which the thin film was formed on a hot plate set at 110 ° C. was heated for 30 minutes. It cooled to room temperature in air | atmosphere, irradiated 20 minutes using said UV ozone apparatus, and formed the anode by carrying out UV ozone treatment of the thin film.

Next, a xylene solution obtained by dissolving the polymer compound B in xylene (manufactured by Kanto Chemical Co., Inc.) at a concentration of 1.5% by weight was applied onto the anode by a spin coating method, After forming the film, the film was dried at 200 ° C. for 60 minutes in a nitrogen atmosphere having an oxygen concentration and a water concentration of 10 ppm or less (weight basis) to form an organic layer.

Next, the luminescent material (“BP361” manufactured by Summation) is dissolved in xylene (manufactured by Kanto Chemical Co.) at a concentration of 1.4% by weight, and the resulting xylene solution is applied onto the organic layer by spin coating. The film was formed to a thickness of about 65 nm. And it dried at 90 degreeC for 10 minute (s) in nitrogen atmosphere whose oxygen concentration and water concentration are 10 ppm or less (weight basis), and formed the light emitting layer. After reducing the pressure to 1.0 × 10 ⁻⁴ Pa or less, barium was deposited on the light emitting layer with a thickness of about 5 nm as a cathode, and then aluminum was deposited on the barium layer with a thickness of about 100 nm. . After vapor deposition, the organic EL element was produced by sealing using a glass substrate.

The drive voltage at which the obtained organic EL element emitted light with a luminance of 100 cd / m ² was 5.66V.

Comparative Example 1
An organic EL device was produced in the same manner as in Example 1 except that the polymer compound A was used instead of the polymer compound B.

The drive voltage at which the obtained organic EL element emitted light with a luminance of 100 cd / m ² was 6.01V.

Comparative Example 2
An ITO film with a thickness of 150 nm was formed on the surface of the glass substrate by sputtering to produce a transparent electrode. On this electrode surface, poly (3,4) ethylenedioxythiophene / polystyrene sulfonic acid (manufactured by HC Starck, trade name: BaytronP: CH8000) was formed by spin coating so as to have a thickness of about 65 nm. After film formation, heat treatment was performed at 200 ° C. for 10 minutes in the air.

An organic EL device was produced in the same manner as in Comparative Example 1 except that a transparent electrode coated with poly (3,4) ethylenedioxythiophene / polystyrenesulfonic acid was used as the anode.

The drive voltage at which the obtained organic EL element emitted light with a luminance of 100 cd / m ² was 6.90V.

Comparative Example 3
An ITO film with a thickness of 45 nm was formed on the surface of the glass substrate by sputtering to produce a transparent electrode. This electrode surface was irradiated for 20 minutes using a UV ozone device (“Model 312 UV-03 cleaning system” manufactured by Technovision) to produce an anode. Next, a xylene solution obtained by dissolving the polymer compound B in xylene (manufactured by Kanto Chemical Co., Inc.) at 1.5% by weight is applied onto the anode by a spin coating method so that the thickness becomes about 80 nm. Then, the film was dried at 200 ° C. for 60 minutes in a nitrogen atmosphere having an oxygen concentration and a water concentration of 10 ppm or less (weight basis) to form an organic layer.

Next, the luminescent material (“BP361” manufactured by Summation) is dissolved in xylene (manufactured by Kanto Chemical Co.) at a concentration of 1.4% by weight, and the resulting xylene solution is applied onto the organic layer by spin coating. The film was formed to a thickness of about 65 nm. And it dried at 90 degreeC for 10 minute (s) in nitrogen atmosphere whose oxygen concentration and water concentration are 10 ppm or less (weight basis), and formed the light emitting layer. After reducing the pressure to 1.0 × 10 ⁻⁴ Pa or less, barium was deposited as a cathode on the light emitting layer film at a thickness of about 5 nm, and then aluminum was deposited on the barium layer at a film thickness of about 100 nm. Vapor deposited. After vapor deposition, the organic EL element was produced by sealing using a glass substrate.

The drive voltage at which the obtained organic EL element emitted light with a luminance of 100 cd / m ² was 8.01V.

1 ... substrate,
2 ... Anode,
3 ... cathode,
4 ... light emitting layer,
5 ... Organic layer,
6 ... electrodes,
7: Coupling membrane.

Claims

An organic electroluminescence device having an anode, a cathode, a light emitting layer containing a light emitting material between the anode and the cathode, and an organic layer between the anode and the light emitting layer,
The anode is an electrode

[Wherein, M 1 represents an atom belonging to Group 4, Group 5, Group 6, Group 13, Group 14 or Group 15 of the Periodic Table. X represents a monovalent organic group having a hetero atom. R a represents an alkyl group, an aryl group, an alkynyl group, an alkenyl group, an arylalkyl group, an arylalkenyl group or an arylalkynyl group. v1 is an integer of 1 to u. u represents the valence of M 1 . When a plurality of X are present, they may be the same or different. When a plurality of R a are present, they may be the same or different. ]
It is immersed in a solution containing the compound represented by formula (1) and a solvent, or a solution containing the compound represented by formula (1) and a solvent is printed or coated on the electrode and dried, whereby the cup is placed on the electrode. It is formed by forming a ring film and then surface-treating the coupling film,
The organic layer has the formula

[Wherein, A ring and B ring are the same or different and each represents an aromatic ring having a bond on the ring; Y 1 represents —O—, —S—, or —C (═O) —; R b represents a monovalent organic group. ]
A layer containing a polymer compound having a repeating unit represented by:
Organic electroluminescence device.
2. The organic electroluminescence device according to claim 1, wherein the surface treatment is UV ozone treatment.
The organic electroluminescence device according to claim 2, wherein the UV irradiation amount in the UV ozone treatment is 1 J / cm 2 or more.
The organic electroluminescence device according to any one of claims 1 to 3, wherein M 1 is a silicon atom or a titanium atom.
The organic electroluminescence device according to any one of claims 1 to 4, wherein Y 1 is -O-.
The difference between the energy level of the highest occupied orbit (HOMO) of the anode and the energy level of the HOMO of the polymer compound having a repeating unit represented by the formula (2) is 0.5 eV or less. The organic electroluminescent element of any one of Claims.
A planar light source comprising the organic electroluminescence element according to any one of claims 1 to 6.
A display device comprising the organic electroluminescence element according to any one of claims 1 to 6.