JP2010093175A - Organic electroluminescent element - Google Patents

Abstract

（１）
[式中、Ｒ¹及びＲ²は、同一又は相異なり、水素原子、アルキル基又はアリール基を表す。Ｒ¹中の炭素原子とＲ²中の炭素原子とが結合し、環を形成してもよい。Ｒ³及びＲ⁴は、同一又は相異なり、アルキル基又はアリール基を表す。ｍ及びｎは、同一又は相異なり、０〜４の整数を表す。]
【選択図】なしAn organic electroluminescence device exhibiting high maximum luminous efficiency is provided.
A low molecular aromatic having a pair of electrodes, at least one of which is transparent or translucent, and a group obtained by removing two hydrogen atoms from the structure represented by formula (1) and a hydroxyl group between the electrodes. An organic electroluminescence device having an organic layer containing at least one compound selected from the group consisting of a compound, estrogen and a non-conjugated polymer compound having a hydroxyl group and a conjugated polymer compound.

(1)
[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group or an aryl group. The carbon atom in R ¹ and the carbon atom in R ² may be bonded to form a ring. R ³ and R ⁴ are the same or different and each represents an alkyl group or an aryl group. m and n are the same or different and represent an integer of 0 to 4. ]
[Selection figure] None

Description

  The present invention relates to an organic electroluminescence element.

  Unlike organic electroluminescent devices using low molecular weight light emitting materials, organic electroluminescent devices using high molecular weight light emitting materials can be used to form the light emitting layer of organic electroluminescent devices using a coating method. ing. For example, an organic electroluminescence element having an organic layer containing polyfluorene which is a conjugated polymer compound is described (Non-Patent Document 1).

Advanced Materials Vol.12 1737-1750 (2000)

  However, the organic electroluminescence device has a problem that the maximum light emission efficiency is not always sufficient.

  Then, an object of this invention is to provide the organic electroluminescent element which shows high maximum luminous efficiency.

（１）
[式中、Ｒ¹及びＲ²は、同一又は相異なり、水素原子、アルキル基又はアリール基を表す。Ｒ¹中の炭素原子とＲ²中の炭素原子とが結合し、環を形成してもよい。Ｒ³及びＲ⁴は、同一又は相異なり、アルキル基又はアリール基を表す。ｍ及びｎは、同一又は相異なり、０〜４の整数を表す。Ｒ³が複数個ある場合、それらは同一でも相異なっていてもよい。Ｒ⁴が複数個ある場合、それらは同一でも相異なっていてもよい。] The present invention provides a low molecular weight aromatic having a pair of electrodes, at least one of which is transparent or translucent, and a group obtained by removing two hydrogen atoms from the structure represented by formula (1) and a hydroxyl group between the electrodes. Provided is an organic electroluminescence device having an organic layer containing at least one compound selected from the group consisting of a compound, estrogen and a non-conjugated polymer compound having a hydroxyl group and a conjugated polymer compound.

(1)
[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group or an aryl group. The carbon atom in R ¹ and the carbon atom in R ² may be bonded to form a ring. R ³ and R ⁴ are the same or different and each represents an alkyl group or an aryl group. m and n are the same or different and represent an integer of 0 to 4. When there are a plurality of R ^{3 s} , they may be the same or different. When there are a plurality of R ⁴ , they may be the same or different. ]

  Since the organic electroluminescence device of the present invention exhibits a high maximum luminous efficiency, the present invention is extremely useful industrially.

  Hereinafter, the present invention will be described in detail.

  The organic electroluminescence device of the present invention comprises a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) and a hydroxyl group, an estrogen and a non-conjugated polymer compound having a hydroxyl group. It has an organic layer containing one or more compounds selected from the group and a conjugated polymer compound.

<Low molecular aromatic compounds>
The low molecular weight aromatic compound that can be used in the present invention has a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) and a hydroxyl group. The molecular weight of the low molecular weight aromatic compound is preferably 94 to 1000.

In the formula (1), the alkyl group represented by R ¹ and R ² may be linear or branched, and may be a cycloalkyl group. Carbon number is about 1-20 normally, As a specific example of an alkyl group, a methyl group, an ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, s-butyl group, 3-methylbutyl group, n-pentyl group, n-hexyl group, 2-ethylhexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, 3,7-dimethyl An octyl group, n-lauryl group, etc. are mentioned. A hydrogen atom in the alkyl group may be substituted with a fluorine atom. Examples of the substituent include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorooctyl group.

（５）
（式（５）中、ｇは１〜６の整数を表し、ｈは０〜５の整数を表す。） In the formula (1), the aryl group represented by R ¹ and R ² is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon, having a benzene ring, having a condensed ring, Those in which two or more of either an independent benzene ring or a condensed ring or both are bonded directly or via a group such as vinylene are also included. The aryl group usually has about 6 to 60 carbon atoms, preferably 6 to 48 carbon atoms. The aryl group may have a substituent. Examples of the substituent include a linear or branched alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms, a linear or branched alkyl group having 1 to 20 carbon atoms, or a carbon number. Examples thereof include an alkoxy group containing 3 to 20 cycloalkyl groups in its structure, a group represented by the formula (5), and a hydroxyl group. Specific examples of the aryl group include a phenyl group, a C _{1 to} C ₁₂ alkoxyphenyl group (C _{1 to} C ₁₂ represents ₁ to ₁₂ carbon atoms, and the same applies to the following), C ₁ to C. ₁₂ alkylphenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, pentafluorophenyl group and the like, and C ₁ -C ₁₂ alkoxyphenyl group, C ₁ -C ₁₂ alkylphenyl group are preferred. Specific examples C ₁ -C ₁₂ alkoxyphenyl group, methoxyphenyl group, ethoxyphenyl group, n- propyloxy phenyl group, isopropyloxyphenyl group, n- butoxyphenyl group, isobutoxyphenyl group, s- butoxyphenyl T-butoxyphenyl group, n-pentyloxyphenyl group, n-hexyloxyphenyl group, cyclohexyloxyphenyl group, n-heptyloxyphenyl group, n-octyloxyphenyl group, 2-ethylhexyloxyphenyl group, n-nonyl Examples thereof include an oxyphenyl group, an n-decyloxyphenyl group, a 3,7-dimethyloctyloxyphenyl group, and an n-lauryloxyphenyl group. C ₁ -C ₁₂ specifically alkylphenyl group include a methylphenyl group, ethylphenyl group, dimethylphenyl group, n- propylphenyl group, mesityl group, methylethylphenyl group, isopropylphenyl group, n- butylphenyl group, isobutyl Phenyl group, s-butylphenyl group, t-butylphenyl group, n-pentylphenyl group, isoamylphenyl group, hexylphenyl group, n-heptylphenyl group, n-octylphenyl group, n-nonylphenyl group, n-decyl Examples thereof include a phenyl group and an n-dodecylphenyl group. A hydrogen atom in the aryl group may be substituted with a fluorine atom.

(5)
(In formula (5), g represents an integer of 1 to 6, and h represents an integer of 0 to 5.)

In formula (1), the definitions and specific examples of alkyl groups and aryl groups represented by R ³ and R ⁴ are the same as those definitions and specific examples of R ¹ and R ² .

Among the low molecular weight aromatic compounds, low molecular weight compounds having a hydroxyphenyl group are preferable. Examples of the low molecular weight aromatic compound having a hydroxyphenyl group include compounds represented by the following formula.

In formula (1), the carbon atom in R ¹ and the carbon atom in R ² may be bonded to form a ring. Examples of the low molecular weight aromatic compound forming a ring include compounds represented by the following formula. The ring may be condensed with an aromatic hydrocarbon ring or a heterocyclic ring.

（２） As said low molecular weight aromatic compound, the compound represented by Formula (2) is preferable.

(2)

（３）
Examples of estrogens that can be used in the present invention include estrone, estradiol, and estriol. Of these, estradiol represented by the formula (3) is preferable.

(3)

The non-conjugated polymer compound that can be used in the present invention has a hydroxyl group. The non-conjugated polymer compound preferably has a polystyrene-equivalent weight average molecular weight of 1 × 10 ³ to 1 × 10 ⁷ .

Examples of the non-conjugated polymer compound include polymer compounds having the following repeating units.

  The organic electroluminescence device of the present invention has an organic layer containing a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) and a hydroxyl group, and a conjugated polymer compound. Is preferred.

<Conjugated polymer compound>
The conjugated polymer compound used in the present invention includes (1) a polymer compound substantially composed of a structure in which double bonds and single bonds are arranged alternately, and (2) a double bond and a single bond contain nitrogen atoms. (3) a structure in which double bonds and single bonds are arranged alternately and a structure in which double bonds and single bonds are arranged through nitrogen atoms. In the present specification, specifically, an unsubstituted or substituted fluorenediyl group, an unsubstituted or substituted benzofluorenediyl group, an unsubstituted or substituted dibenzofurandiyl group, Unsubstituted or substituted dibenzothiophenediyl group, unsubstituted or substituted carbazolediyl group, unsubstituted or substituted thiophenediyl group, unsubstituted or substituted furandyl group, unsubstituted or substituted pyrroldiyl group, unsubstituted or substituted Benzo Repeat one or more selected from the group consisting of an asiazole diyl group, an unsubstituted or substituted phenylene vinylene diyl group, an unsubstituted or substituted thienylene vinylene diyl group, and an unsubstituted or substituted triphenylamine diyl group A polymer compound in which the repeating units are bonded directly or via a linking group.

  In the conjugated polymer compound, when the repeating units are bonded via a linking group, examples of the linking group include phenylene, biphenylene, naphthalenediyl, anthracenediyl, and the like.

（６） （７）
〔式中、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²、Ｒ¹³、Ｒ¹⁴及びＲ¹⁵は、同一又は相異なり、水素原子、アルキル基、アルコキシ基、アルキルチオ基、アリール基、アリールオキシ基、アリールチオ基、アリールアルキル基、アリールアルコキシ基又はアリールアルキルチオ基を表す。〕 The conjugated polymer compound used in the present invention preferably has one or more repeating units selected from the group consisting of formula (6) and formula (7) from the viewpoint of charge transportability.

(6) (7)
[In the formula, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio Represents a group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group or an arylalkylthio group. ]

Equation (6) and the formula (7), the alkyl group represented by R ⁶ to R ^15, specific examples and the like of the aryl groups defined thereof in the R ¹ and R ^2, the same as the specific examples and the like.

In formula (6) and formula (7), the alkoxy group represented by R ^{6 to} R ¹⁵ may be linear or branched, and may be a cycloalkyloxy group. The number of carbon atoms is usually about 1 to 20, and specific examples of the alkoxy group include methoxy group, ethoxy group, n-propyloxy group, i-propyloxy group, n-butoxy group, i-butoxy group, s-butoxy group. Group, t-butoxy group, n-pentyloxy group, n-hexyloxy group, cyclohexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group 3,7-dimethyloctyloxy group, n-lauryloxy group and the like. A hydrogen atom in the alkoxy group may be substituted with a fluorine atom. Examples of the substituent include a trifluoromethoxy group, a pentafluoroethoxy group, a perfluorobutoxy group, a perfluorohexyl group, and a perfluorooctyl group.

In Formula (6) and Formula (7), the alkylthio group represented by R ^{6 to} R ¹⁵ may be linear or branched, and may be a cycloalkylthio group. The number of carbon atoms is usually about 1 to 20, and specific examples of the alkylthio group include methylthio group, ethylthio group, n-propylthio group, isopropylthio group, n-butylthio group, isobutylthio group, s-butylthio group, t- Butylthio group, n-pentylthio group, n-hexylthio group, cyclohexylthio group, n-heptylthio group, n-octylthio group, 2-ethylhexylthio group, n-nonylthio group, n-decylthio group, 3,7-dimethyloctylthio Group, n-laurylthio group and the like. A hydrogen atom in the alkylthio group may be substituted with a fluorine atom. Applicable substituents include a trifluoromethylthio group.

In formula (6) and formula (7), the aryloxy group represented by R ^{6 to} R ¹⁵ usually has about 6 to 60 carbon atoms, preferably 6 to 48, and specific examples of the aryloxy group the phenoxy group, C ₁ -C ₁₂ alkoxy phenoxy group, C ₁ -C ₁₂ alkylphenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, pentafluorophenyloxy group and the like, C ₁ -C ₁₂ alkoxyphenoxy group, C ₁ -C ₁₂ alkylphenoxy group are preferable. Specific examples of C ₁ -C ₁₂ alkoxy include methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, n-pentyloxy, n-hexyloxy, cyclohexyloxy N-heptyloxy, n-octyloxy, 2-ethylhexyloxy, n-nonyloxy, n-decyloxy, 3,7-dimethyloctyloxy, n-lauryloxy and the like. Specific examples of the C ₁ -C ₁₂ alkylphenoxy group include a methylphenoxy group, an ethylphenoxy group, a dimethylphenoxy group, an n-propylphenoxy group, a 1,3,5-trimethylphenoxy group, a methylethylphenoxy group, an isopropylphenoxy group, n-butylphenoxy group, isobutylphenoxy group, s-butylphenoxy group, t-butylphenoxy group, n-pentylphenoxy group, isoamylphenoxy group, n-hexylphenoxy group, n-heptylphenoxy group, n-octylphenoxy group, An n-nonylphenoxy group, an n-decylphenoxy group, an n-dodecylphenoxy group, and the like can be given.

In formula (6) and formula (7), the arylthio group represented by R ^{6 to} R ¹⁵ may have a substituent on the aromatic ring, and usually has about 6 to 60 carbon atoms. specific groups, phenylthio group, C ₁ -C ₁₂ alkoxyphenyl-thio group, C ₁ -C ₁₂ alkyl phenylthio group, 1-naphthylthio group, 2-naphthylthio group, pentafluorophenylthio group, pyridylthio group, pyridazinylthio Group, pyrimidylthio group, pyrazylthio group, triazylthio group and the like.

In formula (6) and formula (7), the arylalkyl group represented by R ^{6 to} R ¹⁵ may have a substituent, the carbon number is usually about 7 to 60, and the arylalkyl group specific, 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.

In formula (6) and formula (7), the arylalkoxy group represented by R ^{6 to} R ¹⁵ may have a substituent, and the number of carbon atoms is usually about 7 to 60. specific, 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 groups, 1-naphthyl -C ₁ -C ₁₂ alkoxy groups, 2-naphthyl -C ₁ -C ₁₂ alkoxy groups and the like.

In formula (6) and formula (7), the arylalkylthio group represented by R ^{6 to} R ¹⁵ may have a substituent, and usually has about 7 to 60 carbon atoms. specific for, 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 group, 2-naphthyl -C ₁ -C ₁₂ alkylthio groups and the like.

The conjugated polymer compound preferably has a polystyrene-equivalent weight average molecular weight of 1 × 10 ³ to 1 × 10 ⁷ from the viewpoint of film forming ability and solubility in a solvent, and is preferably 1 × 10 ³ to 1 × 10 7. ⁶ is more preferable.

  The conjugated polymer compound contained in the organic layer of the organic electroluminescence device of the present invention may be one type or two or more types.

  The conjugated polymer is synthesized with a monomer having a functional group suitable for the polymerization reaction to be used, and then dissolved in an organic solvent as necessary. For example, an alkali, an appropriate catalyst, or a ligand is used. Polymerization can be performed by a known polymerization method such as aryl coupling.

<Organic layer>
The organic layer of the organic electroluminescence device of the present invention has a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by formula (1) and a hydroxyl group, an estrogen, and a non-conjugated group having a hydroxyl group. One or more compounds selected from the group consisting of polymer compounds and conjugated polymer compounds are included. 1 selected from the group consisting of a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) in the organic layer and a hydroxyl group, an estrogen and a non-conjugated polymer compound having a hydroxyl group. The weight of the compound of the seed or more is preferably 0.1 to 10,000 parts by weight, more preferably 1 to 1000 parts by weight with respect to 100 parts by weight of the conjugated polymer compound.

  In the organic layer of the organic electroluminescence device of the present invention, components other than the low-molecular aromatic compound, estrogen, non-conjugated polymer compound, and conjugated polymer compound are contained within a range not impairing the charge transport property and charge injection property. May be included.

<Organic electroluminescence device>
The organic electroluminescence device of the present invention has a pair of electrodes, at least one of which is transparent or translucent, and a group obtained by removing two hydrogen atoms from the structure represented by formula (1) and a hydroxyl group between the electrodes. It has an organic layer containing at least one compound selected from the group consisting of a low-molecular aromatic compound, an estrogen and a non-conjugated polymer compound having a hydroxyl group and the conjugated polymer compound.

  The organic electroluminescence device of the present invention has an anode, a cathode, and an organic layer provided between the anode and the cathode. The organic layer functions as a light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, and the like. In the organic electroluminescent element of the present invention, the organic layer is preferably a light emitting layer.

  The organic electroluminescence device of the present invention includes (1) an organic electroluminescence device in which an electron transport layer is provided between the cathode and the light emitting layer, and (2) a hole transport layer between the anode and the light emitting layer. Examples thereof include an organic electroluminescence element provided, and (3) an organic electroluminescence element in which an electron transport layer is provided between the cathode and the light emitting layer and a hole transport layer is provided between the anode and the light emitting layer.

  The organic electroluminescence device of the present invention is usually formed on a substrate. This substrate may be any substrate that does not change when an electrode is formed and an organic layer is formed. Examples of the material for the substrate include glass, plastic, polymer film, and silicon. In the case of an opaque substrate, the opposite electrode (that is, the electrode far from the substrate) is preferably transparent or translucent.

  Examples of the transparent or translucent electrode material include a conductive metal oxide film and a translucent metal thin film. Specifically, indium oxide, zinc oxide, tin oxide, and a composite film thereof (NESA) manufactured using a conductive material made of indium / tin / oxide (ITO), indium / zinc / oxide, or the like. Etc.), gold, platinum, silver, copper and the like are used, and ITO, indium / zinc / oxide, and tin oxide are preferable. Examples of the method for producing the electrode include a vacuum deposition method, a sputtering method, an ion plating method, a plating method, and the like. Moreover, you may use organic transparent conductive films, such as polyaniline and its derivative (s), polythiophene, and its derivative (s) as an electrode material. Furthermore, as the electrode material, a metal, a conductive polymer, or the like can be used. Preferably, one of the pair of electrodes is preferably a material having a small work function. For example, lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and two of them One or more alloys, or one or more of them and an alloy of one or more of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, graphite, or a graphite intercalation compound are used. It is done. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, calcium-aluminum alloy and the like.

  Materials used for the electron transport layer include oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyanoanthraquinodimethane and its derivatives, fluorenone Derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, polyfluorene and derivatives thereof, and the like. The materials used for the hole transport layer include polyvinyl carbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives, polymer compounds having an aromatic amine residue, polyaniline and derivatives thereof, polythiophene and derivatives thereof, Examples thereof include poly (p-phenylene vinylene) and derivatives thereof, poly (2,5-thienylene vinylene) and derivatives thereof. The organic electroluminescent device of the present invention may further include a buffer layer, and examples of the material used as the buffer layer include alkali metals such as lithium fluoride, halides of alkaline earth metals, and oxides. . In addition, fine particles of inorganic semiconductor such as titanium oxide can be used for the buffer layer.

  The organic layer in the organic electroluminescence device of the present invention has, for example, a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) and a hydroxyl group, an estrogen and a hydroxyl group. An organic thin film containing at least one compound selected from the group consisting of non-conjugated polymer compounds and a conjugated polymer compound can be used.

  The organic thin film has a thickness of usually 1 nm to 100 μm, preferably 2 nm to 1000 nm, more preferably 5 nm to 500 nm, and further preferably 20 nm to 200 nm.

<Method for producing organic thin film>
The organic layer contained in the organic electroluminescence device of the present invention is a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) and a hydroxyl group, an estrogen, and a non-conjugated group having a hydroxyl group. It can be produced using a composition of at least one compound selected from the group consisting of polymer compounds and the conjugated polymer compound.

  It is selected from the group consisting of a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) in the composition and a hydroxyl group, an estrogen and a nonconjugated polymer compound having a hydroxyl group. The weight of the one or more compounds is preferably 0.1 to 10,000 parts by weight and more preferably 1 to 1000 parts by weight with respect to 100 parts by weight of the conjugated polymer compound.

  The method for producing the organic thin film is not particularly limited, and examples thereof include a method by film formation from a solution containing the composition and a solvent, but the thin film may be formed by a vacuum deposition method.

  Solvents used for film formation from a solution include low molecular weight aromatic compounds having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) and a hydroxyl group, estrogens, and non-conjugated polymer compounds having a hydroxyl group. There is no particular limitation as long as it dissolves at least one compound selected from the group and a conjugated polymer compound. Examples of the solvent include unsaturated hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, n-butylbenzene, sec-butylbesen, and t-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane. Halogenated saturated hydrocarbon solvents such as chlorobutane, bromobutane, chlorosulfur pentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane and bromocyclohexane, halogenated unsaturated hydrocarbon solvents such as chlorobenzene, dichlorobenzene and trichlorobenzene, tetrahydrofuran And ether solvents such as tetrahydropyran. Selected from the group consisting of a low molecular weight aromatic compound having a hydroxyl group and a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) used in the present invention, and an unconjugated polymer compound having a hydroxyl group. The composition of one or more compounds and a conjugated polymer compound can usually be dissolved in the solvent in an amount of 0.1% by weight or more.

  For film formation from solution, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic method Coating methods such as a printing method, an offset printing method, an ink jet printing method, a dispenser printing method, a nozzle coating method, a capillary coating method can be used, and a spin coating method, a flexographic printing method, an ink jet printing method, and a dispenser printing method are preferable.

<Application of device>
The organic electroluminescence element described above can be suitably used for a curved or planar illumination device, for example, a planar light source used as a light source of a scanner, and a display device.

  Examples of the display device including the organic electroluminescence element include a segment display device and a dot matrix display device. The dot matrix display device includes an active matrix display device and a passive matrix display device. An organic electroluminescent element is used as a light emitting element constituting each pixel in an active matrix display device and a passive matrix display device. In addition, the organic EL element is used as a light emitting element constituting each segment in the segment display device, and is used as a backlight in the liquid crystal display device.

  Examples will be shown below for illustrating the present invention in more detail, but the present invention is not limited to these examples.

-Method for measuring molecular weight-
In Examples, the number average molecular weight (Mn) and the weight average molecular weight (Mw) were determined in terms of polystyrene by gel permeation chromatography (GPC). Specifically, using a column in which three TSKgel SuperHM-H (manufactured by Tosoh) are connected in series by GPC (manufactured by Tosoh, product name: HLC-8220GPC), the flow rate is 0.5 mL / min using tetrahydrofuran as a developing solvent. And measured at 40 ° C. A differential refractive index detector was used as the detector.

で表される化合物Ａ 6.2171g、下記式：

で表される化合物Ｂ 0.5085g、下記式：

で表される化合物Ｃ 6.2225g、及び下記式：

で表される化合物Ｄ 0.5487gを取り、窒素置換した。トルエン100mlを加え、ジクロロビス（トリフェニルホスフィン）パラジウム（ＩＩ） 7.6mg、炭酸ナトリウム水溶液24mlを加え、還流下で３時間攪拌した。その後、フェニルホウ酸0.40gを加え、終夜攪拌した。その後、ナトリウムＮ，Ｎ−ジエチルジチオカルバメート水溶液を加え、さらに還流下で３時間攪拌した。得られた反応液を分液し、有機相を酢酸水溶液及び水で洗浄した後、メタノール中に滴下したところ、沈殿が生じた。得られた沈殿を、ろ過し、減圧乾燥した後、トルエンに溶解させ、シリカゲル−アルミナカラムを通し、トルエンで洗浄した。得られたトルエン溶液をメタノール中に滴下したところ、沈殿が生じた。得られた沈殿を、ろ過し、減圧乾燥した後、トルエンに溶解させ、メタノールに滴下ところ、沈殿が生じた。得られた沈殿を、ろ過し、減圧乾燥して、7.72gの共役高分子化合物である高分子化合物１を得た。高分子化合物１のポリスチレン換算の数平均分子量Ｍｎは１．２×１０⁵であり、ポリスチレン換算の重量平均分子量Ｍｗは２．９×１０⁵であった。 <Synthesis Example 1> (Synthesis of Conjugated Polymer Compound 1)
Triscaprylylmethylammonium chloride (trade name: Aliquat336 “registered trademark”, manufactured by Aldrich) 1.72 g in a 500 ml four-necked flask, the following formula:

6.2171 g of the compound A represented by the following formula:

Compound B 0.5085 g represented by the following formula:

6.2225 g of the compound C represented by the formula:

The compound D represented by the formula (0.5487 g) was taken and replaced with nitrogen. Toluene (100 ml) was added, dichlorobis (triphenylphosphine) palladium (II) (7.6 mg) and sodium carbonate aqueous solution (24 ml) were added, and the mixture was stirred under reflux for 3 hours. Thereafter, 0.40 g of phenylboric acid was added and stirred overnight. Thereafter, an aqueous sodium N, N-diethyldithiocarbamate solution was added, and the mixture was further stirred for 3 hours under reflux. The obtained reaction solution was separated, and the organic phase was washed with an acetic acid aqueous solution and water, and then dropped into methanol, resulting in precipitation. The obtained precipitate was filtered, dried under reduced pressure, dissolved in toluene, passed through a silica gel-alumina column, and washed with toluene. When the obtained toluene solution was dropped into methanol, precipitation occurred. The obtained precipitate was filtered, dried under reduced pressure, dissolved in toluene, and dropped into methanol, resulting in precipitation. The obtained precipitate was filtered and dried under reduced pressure to obtain 7.72 g of polymer compound 1 as a conjugated polymer compound. The number average molecular weight Mn in terms of polystyrene of the polymer compound 1 was 1.2 × 10 ⁵ , and the weight average molecular weight Mw in terms of polystyrene was 2.9 × 10 ⁵ .

で表される化合物Ｅ 234.06g、下記式：

で表される化合物Ｆ 172.06g、及び下記式：

で表される化合物Ｇ 28.5528gを取り、窒素置換した。アルゴンバブリングしたトルエン2620gを加え、攪拌しながら更に30分間バブリングした。酢酸パラジウム 99.1mg、トリス（ｏ−トリル）ホスフィン 937.0mgを加え、158gのトルエンで洗い流し、95℃に加熱した。17.5重量％炭酸ナトリウム水溶液855gを滴下後、バス温を110℃に昇温し、9.5時間攪拌した後、フェニルホウ酸5.39gをトルエン96mlに溶解して加え、14時間攪拌した。200mlのトルエンを加え、反応液を分液し、有機相を３重量％酢酸水溶液850mlで２回、さらに850mlの水とナトリウムＮ，Ｎ−ジエチルジチオカルバメート19.89gを加え、４時間攪拌した。分液後、シリカゲル−アルミナカラムを通し、トルエンで洗浄した。得られたトルエン溶液をメタノール５０Ｌに滴下したところ、沈殿が生じた。得られた沈殿を、メタノールで洗浄した。減圧乾燥後、１１Ｌのトルエンに溶解させ、得られたトルエン溶液をメタノール５０Ｌに滴下したところ、沈殿が生じた。得られた沈殿を、ろ過し、減圧乾燥して、278.39gの高分子化合物２を得た。高分子化合物２のポリスチレン換算の数平均分子量Ｍｎは７．７×１０⁴であり、ポリスチレン換算の重量平均分子量Ｍｗは３．８×１０⁵であった。 <Synthesis Example 2> (Synthesis of Polymer Compound 2)
Triscaprylylmethylammonium chloride (trade name: Aliquat336 “registered trademark”, manufactured by Aldrich) 40.18 g in a 5 L separable flask, the following formula:

Compound E 234.06 g represented by the following formula:

172.06 g of the compound F represented by the following formula:

28.5528 g of the compound G represented by the formula (1) was taken and replaced with nitrogen. Arranged bubbling toluene (2020 g) was added and bubbling was continued for another 30 minutes. 99.1 mg of palladium acetate and 937.0 mg of tris (o-tolyl) phosphine were added, washed with 158 g of toluene, and heated to 95 ° C. After dropwise addition of 855 g of 17.5 wt% sodium carbonate aqueous solution, the bath temperature was raised to 110 ° C. and stirred for 9.5 hours. Then, 5.39 g of phenylboric acid was dissolved in 96 ml of toluene and stirred for 14 hours. 200 ml of toluene was added, the reaction solution was separated, and the organic phase was added twice with 850 ml of 3% by weight acetic acid aqueous solution, and further 850 ml of water and 19.89 g of sodium N, N-diethyldithiocarbamate were added and stirred for 4 hours. After separation, the solution was passed through a silica gel-alumina column and washed with toluene. When the obtained toluene solution was dropped into 50 L of methanol, precipitation occurred. The resulting precipitate was washed with methanol. After drying under reduced pressure, the product was dissolved in 11 L of toluene, and the resulting toluene solution was dropped into 50 L of methanol, resulting in precipitation. The resulting precipitate was filtered and dried under reduced pressure to obtain 278.39 g of polymer compound 2. The number average molecular weight Mn in terms of polystyrene of the polymer compound 2 was 7.7 × 10 ⁴ , and the weight average molecular weight Mw in terms of polystyrene was 3.8 × 10 ⁵ .

Example 1
(Production and evaluation of organic electroluminescence elements)
It is a low-molecular aromatic compound having a group obtained by dissolving polymer compound 1 in xylene at a concentration of 1.0% by weight and then removing two hydrogen atoms from the structure represented by formula (1) and a hydroxyl group. The compound (H) was mixed with the solution so that the weight was 0.5 times the weight of the polymer compound 1. Subsequently, the solution was filtered through a Teflon (registered trademark) filter having a pore diameter of 0.2 μm to prepare a coating solution A.

（Ｈ）
α,α,α'-トリス(4-ヒドロキシフェニル)-1-エチル-4-イソプロピルベンゼン（東京化成製）

(H)
α, α, α'-Tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (Tokyo Kasei)

A glass substrate with an indium tin oxide (ITO) film having a thickness of 150 nm formed by sputtering is formed by spin coating using a hole injection layer solution (manufactured by Plextronics, trade name: Plexcore HIL-691). On the hot plate in air | atmosphere, it dried for 10 minutes at 120 degreeC, and produced the positive hole injection layer (film thickness: 50 nm). Next, the xylene solution of polymer compound 2 was filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm, and then applied by spin coating, and baked at 180 ° C. for 10 minutes in a nitrogen atmosphere in a glove box. A hole transport layer (film thickness: 20 nm) was prepared. Further, the coating solution A was applied by spin coating to produce a light emitting layer. In manufacturing the light emitting layer, the film thickness was adjusted to 80 nm.
Thereafter, after drying at 90 ° C. under reduced pressure for 1 hour, LiF was vapor-deposited with a thickness of 4 nm, and then Al was vapor-deposited with a thickness of 100 nm. The degree of vacuum at the time of vapor deposition was in the range of 1 × 10 ⁻⁴ Pa to 9 × 10 ⁻³ Pa. The shape of the element was a regular square of 2 mm × 2 mm. By applying a voltage stepwise to the obtained device, current density and light emission luminance were measured. The luminous efficiency was calculated by dividing the luminous luminance by the current density. Table 1 shows the maximum luminous efficiency.

（Ｉ）
2,2'-メチレンビス[6-(2-ヒドロキシ-5-メチルベンジル)-p-クレゾール]（東京化成製） Example 2
(Production and evaluation of organic electroluminescence elements)
An organic electroluminescence device was prepared in the same manner as in Example 1 except that the compound (I) was used instead of the compound (H), and the maximum luminous efficiency of the organic electroluminescence device was determined. The measurement results are shown in Table 1.

(I)
2,2'-methylenebis [6- (2-hydroxy-5-methylbenzyl) -p-cresol] (manufactured by Tokyo Chemical Industry)

（Ｊ）
4,4'-ジヒドロキシテトラフェニルメタン（東京化成製）
比較例１
（有機エレクトロルミネッセンス素子の作製、評価）
化合物（Ｈ）を用いない以外は実施例１と同様の方法で有機エレクトロルミネッセンス素子を作製し、有機エレクトロルミネッセンス素子の最大発光効率を求めた。測定結果を表１に示す。
Example 3
(Production and evaluation of organic electroluminescence elements)
An organic electroluminescent device was produced in the same manner as in Example 1 except that the compound (J) was used instead of the compound (H), and the maximum luminous efficiency of the organic electroluminescent device was determined. The measurement results are shown in Table 1.

(J)
4,4'-Dihydroxytetraphenylmethane (manufactured by Tokyo Chemical Industry)
Comparative Example 1
(Production and evaluation of organic electroluminescence elements)
An organic electroluminescent element was produced in the same manner as in Example 1 except that the compound (H) was not used, and the maximum luminous efficiency of the organic electroluminescent element was determined. The measurement results are shown in Table 1.

-Evaluation-
As can be seen from Table 1, a conjugated polymer compound (polymer compound 1) and a low molecular weight aromatic compound having a hydroxyl group and a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) (compound ( H), an organic electroluminescent device having a light emitting layer formed using a composition containing compound (I) and compound (J)) has two hydrogen atoms from the structure represented by the formula (1). The maximum luminous efficiency was higher than that of an organic electroluminescence device having a light emitting layer formed using a composition not containing a low molecular weight aromatic compound having a removed group and a hydroxyl group.

Claims (4)

A pair of electrodes, at least one of which is transparent or translucent, and a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by formula (1) and a hydroxyl group, estrogen, An organic electroluminescence device having an organic layer containing at least one compound selected from the group consisting of non-conjugated polymer compounds having a hydroxyl group and a conjugated polymer compound.

(1)
[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group or an aryl group. The carbon atom in R ¹ and the carbon atom in R ² may be bonded to form a ring. R ³ and R ⁴ are the same or different and each represents an alkyl group or an aryl group. m and n are the same or different and represent an integer of 0 to 4. When there are a plurality of R ^{3 s} , they may be the same or different. When there are a plurality of R ⁴ , they may be the same or different. ]   The organic electroluminescence device according to claim 1, wherein the low-molecular aromatic compound is a compound having a hydroxyphenyl group. The organic electroluminescence device according to claim 1, wherein the low-molecular aromatic compound is a compound represented by the formula (2).

(2)
  1 selected from the group consisting of a low molecular weight aromatic compound having a group obtained by removing two hydrogen atoms from the structure represented by the formula (1) in the organic layer and a hydroxyl group, an estrogen and a nonconjugated polymer compound having a hydroxyl group. The organic electroluminescence device according to any one of claims 1 to 3, wherein the weight of the compound of the seed or more is 0.1 to 10,000 parts by weight with respect to 100 parts by weight of the conjugated polymer compound.