JP2009278077A - Organic electroluminescence element material, composition for organic electroluminescence element, organic electroluminescence element, organic el display, and organic el illumination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescence element material which is soluble in various solvents and forms an organic layer of an organic electroluminescence element by a wet film formation process to allow manufacturing of the organic electroluminescence element having a low driving voltage and a sufficient lifetime. <P>SOLUTION: The organic electroluminescence element material is used for the organic layer formed by the wet film formation process, of the organic electroluminescence element and comprises a compound represented by a formula (1) wherein: Ar<SP>1</SP>is an aromatic ring which may have a substituent and has ≤30 carbon atoms; a ring A is an aromatic ring which may have a substituent and has ≤30 carbon atoms; Ar<SP>1</SP>is coupled to an ortho position with respect to a coupling position of an anthracene ring to the ring A; L<SP>1</SP>is an aromatic ring which may have a substituent and has ≤50 carbon atoms, or an atom group of linking aromatic rings; and an anthracene ring and a pyrene ring to which the L<SP>1</SP>is coupled may have substituents. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescent element material and an organic electroluminescent element composition used for forming an organic layer of an organic electroluminescent element by a wet film formation method, and a wet process using the organic electroluminescent element composition. The present invention relates to an organic electroluminescent element having an organic layer formed by a film forming method, an organic EL display using the organic electroluminescent element, and organic EL illumination.

In recent years, as a thin film type electroluminescent element, an organic electroluminescent element using an organic thin film has been developed instead of using an inorganic material. Organic electroluminescent devices are usually formed by providing a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, etc. between the anode and the cathode, and materials suitable for each layer are being developed. . In addition, the light emission colors of organic electroluminescent elements are being developed in red, green, and blue, respectively.
However, blue organic electroluminescent elements have not been satisfactory in terms of efficiency, life, and heat resistance, and there is a problem that application to full color display is limited.

  As a method for forming each constituent layer of the organic electroluminescent element, there are a vacuum vapor deposition method and a wet film formation method. Among these, the vacuum deposition method has a problem in terms of yield when manufacturing a medium- or large-sized full-color panel for a television or a monitor. Therefore, the wet film-forming method is suitable for these large area applications.

  However, in order to form an organic layer of an organic electroluminescent element by a wet film formation method, the material for forming the organic layer is dissolved in a solvent, and the high performance required as a component layer of the element after the wet film formation is achieved. It is desirable to have. However, even materials that have been conventionally developed for wet film forming methods often do not satisfy the conditions required for such wet film forming methods.

  For example, Patent Document 1 discloses an element manufactured by a wet film formation method using a material represented by the following formula.

  Patent Document 2 discloses an element manufactured by a wet film forming method using a material represented by the following formula.

  However, these materials do not satisfy the physical properties required in the process of wet film formation such as solubility in solvents and heat resistance, and the driving voltage is high or sufficient life is not obtained even when used for an element. There were problems such as.

International Publication No. 2006/070712 Pamphlet JP 2004-224766 A

  The present invention is an organic electric field which is soluble in various solvents and can form an organic electroluminescent device having a low driving voltage and a sufficient lifetime by forming an organic layer of the organic electroluminescent device by a wet film forming method. Light emitting device material, composition for organic electroluminescent device, organic electroluminescent device having organic layer formed by wet film forming method using composition for organic electroluminescent device, and organic electroluminescent device An object is to provide an organic EL display and organic EL illumination.

  As a result of intensive studies by the present inventors, it has been found that the above problem can be solved by using a compound represented by the following formula (1), and the present invention has been achieved.

That is, the present invention
An organic electroluminescent element material comprising a compound represented by the following formula (1), which is a material used for an organic layer formed by a wet film-forming method of an organic electroluminescent element:
An organic electroluminescent element composition comprising the organic electroluminescent element material and a solvent,
An organic electroluminescence device having an organic layer between an anode and a cathode, wherein at least one of the organic layers is a layer formed by wet deposition using the composition for organic electroluminescence device Light emitting element,
Organic EL display and organic EL illumination using the organic electroluminescent element,
Exist.

(In formula (1), Ar ¹ represents an aromatic ring having 30 or less carbon atoms which may have a substituent. Ring A represents an aromatic ring having 30 or less carbon atoms which may have a substituent. , Ar ¹ is bonded to the ortho position with respect to the bonding position of the anthracene ring to ring A. L ¹ is an aromatic ring having 50 or less carbon atoms which may have a substituent or an atom formed by connecting aromatic rings. (The anthracene ring and pyrene ring to which L ¹ is bonded may have a substituent.)

  By forming the organic layer of the organic electroluminescent element by the wet film formation method using the organic electroluminescent element material of the present invention, an organic electroluminescent element having a low driving voltage and a sufficient lifetime can be obtained.

It is typical sectional drawing which showed an example of the organic electroluminescent element of this invention.

  Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention.

[Explanation of words]
In the present invention, the simple term “aromatic ring” includes both an aromatic hydrocarbon ring and an aromatic heterocyclic ring.
In the present invention, the term “(hetero) aryl” includes both an aromatic hydrocarbon ring and an aromatic heterocycle.
In the present invention, “may have a substituent” means that one or more substituents may be present.

[Materials for organic electroluminescent elements]
The organic electroluminescent element material of the present invention is a material used for an organic layer formed by a wet film-forming method of an organic electroluminescent element, and is composed of a compound represented by the following formula (1). .

(In formula (1), Ar ¹ represents an aromatic ring having 30 or less carbon atoms which may have a substituent. Ring A represents an aromatic ring having 30 or less carbon atoms which may have a substituent. , Ar ¹ is bonded to the ortho position with respect to the bonding position of the anthracene ring to ring A. L ¹ is an aromatic ring having 50 or less carbon atoms which may have a substituent or an atom formed by connecting aromatic rings. (The anthracene ring and pyrene ring to which L ¹ is bonded may have a substituent.)

The compound represented by the formula (1) is a compound in which an anthracene molecule having high steric hindrance is bonded to a pyrene ring via a linking group. From the positional relationship between Ar ¹ and the anthracene ring, this compound is presumed to improve the solubility and film property of the compound because the planarity between the anthracene ring and ring A is destroyed by steric hindrance. On the other hand, since the transition state is inhibited by steric hindrance, the charge transfer ability is lowered as a compound, but it is presumed that the charge transfer ability is improved by introducing a pyrene ring into the molecule. Moreover, it is estimated that charge durability improves by having an anthracene ring. Use of such a compound in an organic layer of an organic electroluminescent element formed by a wet film forming method is considered to lead to an improvement in durability, a reduction in driving voltage, and an increase in life of the organic electroluminescent element.

  The wet film forming method in the present invention is a spin coating method, a dip coating method, a die coating method, a bar coating method, a blade coating method, a roll coating method, a spray coating method, a capillary coating method, an ink jet method, a screen printing method, A method of forming a film using an ink containing a solvent, such as a gravure printing method, a flexographic printing method, and an offset printing method. Of these, the die coating method, the roll coating method, the spray coating method, the ink jet method, and the flexographic printing method are preferable from the viewpoint of easy patterning.

  Hereinafter, each component in the above formula (1) will be described in detail.

<About Ar ¹ >
Ar ¹ represents an aromatic ring having 30 or less carbon atoms which may have a substituent.
Examples of the aromatic ring include benzene ring, naphthalene ring, anthracene ring, naphthacene ring, chrysene ring, pyrene ring, triphenylene ring, coronene ring and other aromatic hydrocarbon rings, thiophene ring, furan ring, pyrrole ring, pyridine ring And aromatic heterocycles such as a pyrimidine ring, pyridazine ring, pyrazine ring, quinoline ring, isoquinoline ring, indole ring, benzothiophene ring, benzofuran ring, dibenzofuran ring, dibenzothiophene ring, and carbazole ring. Of these, a benzene ring, a naphthalene ring, a pyridine ring, a dibenzofuran ring and a dibenzothiophene ring are preferable, a benzene ring and a naphthalene ring are particularly preferable, and a benzene ring is most preferable from the viewpoint of the stability of the compound.

Ar ¹ preferably has no substituent, but when it has a substituent, the substituent includes an alkyl group having 1 to 20 carbon atoms and an aromatic group having 6 to 25 carbon atoms. Hydrocarbon group, aromatic heterocyclic group having 3 to 20 carbon atoms, alkyloxy group having 1 to 20 carbon atoms, (hetero) aryloxy group having 3 to 20 carbon atoms, alkylthio group having 1 to 20 carbon atoms, carbon number A 3-20 (hetero) arylthio group and a cyano group are mentioned. Among these, as the substituent that Ar ¹ has, an alkyl group having 1 to 20 carbon atoms and an aromatic hydrocarbon group having 6 to 25 carbon atoms are preferable from the viewpoint of stability of the compound, and an aromatic hydrocarbon group is particularly preferable. preferable.

As more specific examples of a preferable Ar ¹ is the substituent which may have, include the following.

  Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group and cyclohexyl group. Group, decyl group, octadecyl group and the like. Among these, Preferably, they are a methyl group, an ethyl group, and an isopropyl group, and a methyl group and an ethyl group are preferable from the point of being easy to obtain a raw material and cheap, and an iso-butyl group and a sec-butyl group. , Tert-butyl group is preferable because of its high solubility in nonpolar solvents.

  Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms include a naphthyl group such as a phenyl group, a 1-naphthyl group and a 2-naphthyl group, a phenanthyl group such as a 9-phenanthyl group and a 3-phenanthyl group, and 1-anthryl. Group, 2-anthryl group, anthryl group such as 9-anthryl group, 1-naphthacenyl group, naphthacenyl group such as 2-naphthacenyl group, 1-chrysenyl group, 2-chrysenyl group, 3-chrysenyl group, 4-chrysenyl group, 5-chrycenyl group, 6-chrycenyl group and other chrycenyl groups, 1-pyrenyl group and other pyrenyl groups, 1-triphenylenyl group and other triphenylenyl groups, 1-coronenyl group and other coronenyl groups, 4-biphenyl group and 3-biphenyl group In view of the stability of the compound, phenyl group, 2-naphthyl group, 1-ant Group, 9-phenanthryl group, 9-anthranyl group, a 4-biphenyl group, a 3-biphenyl group preferably a phenyl group, a 2-naphthyl group, 3-biphenyl group is particularly preferable from the purification ease of the compound.

  Examples of the aromatic heterocyclic group having 3 to 20 carbon atoms include thienyl group such as 2-thienyl group, furyl group such as 2-furyl group, imidazolyl group such as 2-imidazolyl group, and carbazolyl such as 9-carbazolyl group. Groups, pyridyl groups such as 2-pyridyl group, triazin-yl groups such as 1,3,5-triazin-2-yl group, and the like. Of these, a 9-carbazolyl group is preferable from the viewpoint of stability of the compound.

  Examples of the alkyloxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, isopropyloxy group, cyclohexyloxy group, octadecyloxy group and the like.

  Examples of the (hetero) aryloxy group having 3 to 20 carbon atoms include phenoxy group, 1-naphthyloxy group, 9-anthranyloxy group, 2-thienyloxy group and the like.

  Examples of the alkylthio group having 1 to 20 carbon atoms include methylthio group, ethylthio group, isopropylthio group, cyclohexylthio group and the like.

  Examples of the (hetero) arylthio group having 3 to 20 carbon atoms include a phenylthio group, a 1-naphthylthio group, a 9-anthranylthio group, and a 2-thienylthio group.

In addition, when Ar ¹ has a substituent, the substitution position is preferably a para-position or a meta-position, and more preferably a meta-position, relative to the substitution position of Ar ^{1 on} the ring A.
Ar ¹ preferably has a molecular weight of 500 or less, including its substituents, for purification of the compound.

<About Ring A>
Ring A represents an optionally substituted aromatic ring group having 30 or less carbon atoms, and Ar ¹ is bonded to the ortho position relative to the bonding position of the anthracene ring to Ring A.

  Examples of the aromatic ring of ring A include benzene ring, naphthalene ring, anthracene ring, naphthacene ring, chrysene ring, pyrene ring, triphenylene ring, coronene ring and other aromatic hydrocarbon rings, thiophene ring, furan ring, pyrrole ring, Examples thereof include aromatic heterocycles such as a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a quinoline ring, an isoquinoline ring, an indole ring, a benzothiophene ring, a benzofuran ring, a dibenzofuran ring, a dibenzothiophene ring, and a carbazole ring. Of these, a benzene ring, a naphthalene ring, a pyridine ring, a dibenzofuran ring and a dibenzothiophene ring are preferable, a benzene ring and a naphthalene ring are particularly preferable, and a benzene ring is most preferable from the viewpoint of the stability of the compound.

  When ring A is a benzene ring, the compound represented by the formula (1) is represented by the following formula (2).

(In the formula (2), Ar ¹ and ^{L 1} is an anthracene ring and pyrene ring .L ¹ is as defined as in the formula (1) are attached may have a substituent. In addition, Ar ¹ is (The benzene ring to be bonded may have a substituent.)

  Ring A may have a substituent. Specific examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, and 3 to 20 carbon atoms. Aromatic heterocyclic group, C 1-20 alkyloxy group, C 3-20 (hetero) aryloxy group, C 1-20 alkylthio group, C 3-20 (hetero) arylthio group And a cyano group. Among these, as a substituent which the ring A has, the C1-C20 alkyl group and the C6-C25 aromatic hydrocarbon group are preferable from the surface of the stability of a compound, and an aromatic hydrocarbon group is especially preferable. preferable.

Specific examples of these substituents are the same as those exemplified as the substituent that Ar ¹ may have.

  In addition, when ring A is a benzene ring and has a substituent, the substitution position is ortho-position or meta-position from the viewpoint of maintaining high solubility with respect to the substitution position of ring A to the anthracene ring. Are preferred, and the ortho position is particularly preferred. From the viewpoint of heat resistance, the para position or the meta position is preferable, and the para position is particularly preferable.

<For ^{L 1>}
L ¹ is a group consisting of an aromatic ring having 50 or less carbon atoms which may have a substituent or an atomic group formed by connecting aromatic rings.

Examples of the aromatic ring constituting L ¹ include benzene ring, naphthalene ring, anthracene ring, naphthacene ring, chrysene ring, pyrene ring, triphenylene ring, coronene ring, thiophene ring, furan ring, pyrrole ring, pyridine ring, pyrimidine ring , Pyridazine ring, pyrazine ring, quinoline ring, isoquinoline ring, indole ring, benzothiophene ring, benzofuran ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring and the like. Of these, a benzene ring, a naphthalene ring, a pyridine ring, a dibenzofuran ring and a dibenzothiophene ring are preferable, a benzene ring and a naphthalene ring are particularly preferable, and a benzene ring is most preferable from the viewpoint of the stability of the compound.

L ¹ may consist of only one of these rings, or two or more of these rings may be linked to form an atomic group having 50 or less carbon atoms.

Examples of L ¹ comprising an atomic group formed by connecting rings include biphenyl, ortho-terphenyl, meta-terphenyl, para-terphenyl, 1-phenylnaphthalene, 2-phenylnaphthalene, 9-phenylanthracene, 9 , 10-diphenylanthracene, 2-phenylpyridine, 4-phenylpyridine, 2-phenylquinoline, 1,3,5-triphenyltriazole, 9-phenylcarbazole and the like become divalent groups.

L ¹ is preferably a benzene ring, biphenyl, meta-terphenyl, 9,10-diphenylanthracene, or a divalent group derived from 4-phenylpyridine, and more preferably a benzene ring, biphenyl, or 9,10-diphenyl. It is a divalent group derived from anthracene, particularly preferably a benzene ring or a divalent group derived from biphenyl, and most preferably a divalent group derived from a benzene ring, that is, a phenylene group.

L ¹ may have a substituent, and specific examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, and 3 to 20 carbon atoms. Aromatic heterocyclic group, C 1-20 alkyloxy group, C 3-20 (hetero) aryloxy group, C 1-20 alkylthio group, C 3-20 (hetero) arylthio group And a cyano group. Among these, the substituent that L ¹ has is preferably an alkyl group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 25 carbon atoms, particularly preferably an aromatic hydrocarbon group, from the viewpoint of the stability of the compound. .

Specific examples of these substituents are the same as those exemplified as the substituent that Ar ¹ may have.
L ¹ , including its substituents, preferably has a molecular weight of 800 or less, more preferably a molecular weight of 500 or less, and most preferably a molecular weight of 300 or less, from the viewpoint of ease of purification of the compound.

<About pyrene ring and anthracene ring>
The anthracene ring and pyrene ring to which L ¹ is bonded may have a substituent. The anthracene ring and the pyrene ring to which L ¹ is bonded are an anthracene ring and a pyrene ring bonded through L ¹ in the formula (1).

  The anthracene ring and the pyrene ring which may have a substituent are preferably a substituent having 50 or less carbon atoms, and the substituent may further have a substituent.

  Specific examples of the substituent that the anthracene ring and the pyrene ring may have include an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon ring group having 6 to 25 carbon atoms, and an aromatic group having 3 to 20 carbon atoms. Heterocyclic group, C1-C20 alkyloxy group, C3-C20 (hetero) aryloxy group, C1-C20 alkylthio group, C3-C20 (hetero) arylthio group, cyano group Is mentioned. Among these, as a substituent which an anthracene ring and a pyrene ring have, from the surface of stability of a compound, a C1-C20 alkyl group, a C6-C25 aromatic hydrocarbon group, C3-C20 The aromatic heterocyclic group is preferably, and the aromatic hydrocarbon ring group is particularly preferable.

  Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group and cyclohexyl group. Group, decyl group, octadecyl group and the like. Among these, Preferably, they are a methyl group, an ethyl group, and an isopropyl group, and a methyl group and an ethyl group are preferable from the point of being easy to obtain a raw material and cheap, and an iso-butyl group and a sec-butyl group. , Tert-butyl group is preferable because of its high solubility in nonpolar solvents.

  Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms include a naphthyl group such as a phenyl group, a 1-naphthyl group and a 2-naphthyl group, a phenanthyl group such as a 9-phenanthyl group and a 3-phenanthyl group, and 1-anthryl. Group, 2-anthryl group, anthryl group such as 9-anthryl group, 1-naphthacenyl group, naphthacenyl group such as 2-naphthacenyl group, 1-chrysenyl group, 2-chrysenyl group, 3-chrysenyl group, 4-chrysenyl group, 5-chrycenyl group, 6-chrycenyl group and other chrycenyl groups, 1-pyrenyl group and other pyrenyl groups, 1-triphenylenyl group and other triphenylenyl groups, 1-coronenyl group and other coronenyl groups, 4-biphenyl group and 3-biphenyl group In view of the stability of the compound, phenyl group, 2-naphthyl group, 1-ant Group, 9-phenanthryl group, 9-anthranyl group is preferably a phenyl group, 2-naphthyl group is particularly preferred from the purification ease of the compound.

  Examples of the aromatic heterocyclic group having 3 to 20 carbon atoms include thienyl group such as 2-thienyl group, furyl group such as 2-furyl group, imidazolyl group such as 2-imidazolyl group, and carbazolyl such as 9-carbazolyl group. Groups, pyridyl groups such as 2-pyridyl group, triazin-yl groups such as 1,3,5-triazin-2-yl group, and the like. Of these, a 9-carbazolyl group is preferable from the viewpoint of stability of the compound.

  Examples of the alkyloxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, isopropyloxy group, cyclohexyloxy group, octadecyloxy group and the like. Of these, a methoxy group and an ethoxy group are preferable from the viewpoint of improving solubility in a solvent and the glass transition point of the compound, that is, heat resistance.

  Examples of the (hetero) aryloxy group having 3 to 20 carbon atoms include a phenoxy group, a 3-phenoxyphenoxy group, a 2-naphthyloxy group, a 9-anthranyloxy group, and a 2-thienyloxy group. Among these, a phenoxy group, a 3-phenoxyphenoxy group, and a 2-naphthyloxy group are preferable from the viewpoint of improving solubility in a solvent, and a 3-phenoxyphenoxy group is particularly preferable.

  Examples of the alkylthio group having 1 to 20 carbon atoms include methylthio group, ethylthio group, isopropylthio group, cyclohexylthio group and the like. Among these, a methylthio group and an ethylthio group are preferable from the viewpoint of improving solubility in a solvent and the glass transition point of the compound, that is, heat resistance.

  Examples of the (hetero) arylthio group having 3 to 20 carbon atoms include a phenylthio group, a 1-naphthylthio group, a 9-anthranylthio group, and a 2-thienylthio group. Among these, a phenylthio group is preferable from the viewpoint of improving solubility in a solvent.

In addition, these substituents may have a substituent, and examples of the substituent include the same substituents that Ar ¹ may have.

<About molecular weight>
The molecular weight of the compound represented by the formula (1) is usually 7000 or less, preferably 5,000 or less when considering the ease of purification of the compound, and particularly preferably when considering solubility in a solvent. When considering high purity by sublimation purification, it is most preferably 1500 or less. In general, the molecular weight of the compound represented by the formula (1) is 500 or more, and when considering the thermal stability of the compound, the molecular weight is preferably 600 or more.

<Solubility in solvent>
The compound represented by the formula (1) is preferably one that usually dissolves in an amount of 0.5% by weight or more with respect to toluene. Preferably, those that dissolve more than 1.5% by weight are more preferable because the film thickness of the coating film is easy to control, and those that dissolve more than 2.0% by weight are particularly preferable from the viewpoint of long-term storage stability. Preferably, those that dissolve at least 2.5% by weight are most preferred.

<About glass transition temperature>
The compound represented by the formula (1) preferably has a glass transition temperature Tg of 120 ° C. or higher.

<Specific example>
Although the specific example of a compound represented by Formula (1) below is given, it is not limited to the following exemplary compounds.

[Composition for organic electroluminescence device]
The composition for organic electroluminescent elements of the present invention contains the above-described organic electroluminescent element material of the present invention and a solvent.

  The content of the organic electroluminescent element material of the present invention in the composition for organic electroluminescent elements is usually 0.1% by weight or more, preferably 1% by weight or more, and usually 99.99% by weight or less, preferably 99.9%. % By weight or less. By setting the content of the organic electroluminescent element material in the composition within this range, holes and electrons are efficiently injected from the adjacent layer (for example, hole transport layer or hole blocking layer) to the light emitting layer. In other words, the drive voltage can be reduced. Further, by dispersing the dopant material or the host material efficiently and uniformly, the effects of suppressing the concentration quenching and improving the light emission efficiency, lowering the voltage, and extending the lifetime can be obtained. In addition, the organic electroluminescent element material of this invention may be contained only 1 type in the composition for organic electroluminescent elements of this invention, and may be contained in combination of 2 or more type.

  The solvent contained in the composition for organic electroluminescent elements of the present invention is a volatile liquid component used for forming a layer containing an organic electroluminescent element material by wet film formation.

  The solvent is not particularly limited as long as it is a solvent in which the organic electroluminescent element material of the present invention which is a solute and a charge transporting compound described later are well dissolved, and preferred solvents include the following.

For example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene, and tetralin; halogenated fragrances such as chlorobenzene, dichlorobenzene, and trichlorobenzene Group hydrocarbons: 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethyl Aromatic ethers such as anisole and diphenyl ether; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; Alicyclic ketones such as Sanone, Cyclooctanone and Fencon; Alicyclic alcohols such as cyclohexanol and cyclooctanol; Aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; Aliphatic alcohols such as butanol and hexanol; Ethylene And aliphatic ethers such as glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA).
Of these, alkanes and aromatic hydrocarbons are preferable.

  One of these solvents may be used alone, or two or more thereof may be used in any combination and ratio.

  The boiling point of the solvent is usually 100 ° C. or higher, preferably 150 ° C. or higher, more preferably 200 ° C. or higher. Below this range, there is a possibility that the film formation stability may be reduced due to solvent evaporation from the composition for organic electroluminescent elements during wet film formation.

  In order to obtain a more uniform film, it is preferable that the solvent evaporates from the liquid film immediately after the film formation at an appropriate rate. For this reason, the boiling point of the solvent is usually 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and usually 270 ° C. or lower, preferably 250 ° C. or lower, more preferably 230 ° C. or lower.

  The content of the solvent is preferably 10 parts by weight or more, more preferably 50 parts by weight or more, particularly preferably 80 parts by weight or more, and preferably 99.95 with respect to 100 parts by weight of the composition for organic electroluminescent elements. The amount is not more than parts by weight, more preferably not more than 99.9 parts by weight, particularly preferably not more than 99.8 parts by weight. When the content of the solvent is less than this lower limit, the viscosity of the composition for organic electroluminescent elements becomes too high, and film forming workability may be lowered. On the other hand, if the upper limit is exceeded, the thickness of the film obtained by removing the solvent after film formation cannot be obtained, so that film formation tends to be difficult.

  The composition for an organic electroluminescent device of the present invention may contain a charge transporting compound used for an organic electroluminescent device, particularly a light emitting layer, in addition to the above-mentioned organic electroluminescent device material and solvent.

  When forming the light emitting layer of an organic electroluminescent element using the composition for organic electroluminescent elements of the present invention, the organic electroluminescent element material of the present invention is used as a host material, and another charge transporting compound is used as a dopant material. The organic electroluminescent element material of the present invention may be used as a dopant material, and another charge transporting compound may be included as a host material. Further, both the dopant material and the host material may be the organic electroluminescent element material of the present invention.

As other charge transporting compounds that can be contained in the composition for organic electroluminescent elements of the present invention, those conventionally used as materials for organic electroluminescent elements can be used. For example, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthene, benzophenanthrene, fluorene, acetonaphthofluoranthene, coumarin, p-bis (2-phenylethenyl) benzene and derivatives thereof, quinacridone Derivatives, DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, arylamino groups And the condensed aromatic ring compounds and styryl derivatives substituted with an arylamino group.
One of these may be used alone, or two or more may be used in any combination and ratio.

The content of the other charge transporting compound in the composition for organic electroluminescent elements of the present invention is usually 1 part by weight or more and usually 50 parts by weight or less, preferably 30 parts, when the composition is 100 parts by weight. Less than parts by weight.
Further, the content of the other charge transporting compound in the composition for organic electroluminescent elements is usually 50% by weight or less with respect to the organic electroluminescent element material of the present invention in the composition for organic electroluminescent elements. It is preferably 30% by weight or less, usually 0.01% by weight or more, and particularly preferably 0.1% by weight or more.

  The composition for organic electroluminescent elements of the present invention may further contain other compounds in addition to the above-described compounds as necessary. For example, in addition to the above solvent, another solvent may be contained. Examples of such a solvent include amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and dimethyl sulfoxide. One of these may be used alone, or two or more may be used in any combination and ratio.

  Moreover, the organic electroluminescent element material of this invention may contain various additives, such as a leveling agent and an antifoamer, for the purpose of improving film forming property.

[Organic electroluminescence device]
The organic electroluminescent device of the present invention has an organic layer between an anode and a cathode, and at least one of the organic layers is a layer formed by a wet film using the above-described composition for an organic electroluminescent device of the present invention. It is characterized by being. The organic layer may be composed of one layer or may be composed of two or more layers. In addition to the organic layer, a layer made of an inorganic compound may be provided between the anode and the cathode.

  The structure of the organic electroluminescent element of the present invention will be described below according to the element structure of FIG. 1 showing an example of the structure of the organic electroluminescent element of the present invention. The organic electroluminescent element of the present invention is an organic electroluminescent element of the present invention. It is only necessary to have a layer formed by wet deposition using the composition for use between the anode and the cathode, and other layers may or may not be included.

<Board>
The substrate 1 serves as a support for the organic electroluminescent element, and a quartz or glass plate, a metal plate or a metal foil, a plastic film, a sheet, or the like is used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polyethersulfone is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may be deteriorated by the outside air that has passed through the substrate, which is not preferable. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

<Anode>
An anode 2 is provided on the substrate 1. The anode 2 plays a role of hole injection into a layer (hole injection layer 3 or the like) on the light emitting layer side.

  This anode 2 is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum, a metal oxide such as an oxide of indium and / or tin, a metal halide such as copper iodide, carbon black, or A conductive polymer such as poly (3-methylthiophene), polypyrrole, or polyaniline is used.

  In general, the anode 2 is often formed by sputtering, vacuum deposition, or the like. In addition, when forming an anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, or conductive polymer fine powder, an appropriate binder resin solution is used. The anode 2 can also be formed by dispersing and coating the substrate 1. Further, in the case of a conductive polymer, a thin film can be directly formed on the substrate 1 by electrolytic polymerization, or the anode 2 can be formed by applying a conductive polymer on the substrate 1 (Appl. Phys. Lett. 60, 2711, 1992).

  The anode 2 usually has a single-layer structure, but it can also have a laminated structure made of a plurality of materials if desired.

  The thickness of the anode 2 varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably about 500 nm or less. When it may be opaque, the thickness of the anode 2 is arbitrary, and the anode 2 may be the same as the substrate 1. Furthermore, it is also possible to laminate different conductive materials on the anode 2 described above.

  The surface of the anode is treated with ultraviolet (UV) / ozone, oxygen plasma, or argon plasma for the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve hole injection. Is preferred.

<Hole injection layer>
Since the hole injection layer 3 is a layer that transports holes from the anode 2 to the light emitting layer 4, the hole injection layer 3 preferably contains a hole transporting compound.

  The method for forming the hole injection layer 3 is not particularly limited, but is preferably formed by a wet film formation method from the viewpoint of reducing dark spots. The wet film-forming method can obtain a homogeneous and defect-free thin film as compared with the conventional vacuum vapor deposition method, has a short time for film formation, and is industrially superior.

  When the hole injection layer 3 is formed by wet film formation, the material for the hole injection layer 3 is usually mixed with a suitable solvent (solvent for the hole injection layer) to form a composition for film formation (hole injection). A composition for forming a layer) and coating the composition for forming a hole injection layer on a layer (usually the anode 2) corresponding to the lower layer of the hole injection layer 3 by an appropriate technique. Then, the hole injection layer 3 is formed by drying.

(Hole transporting compound)
The composition for forming a hole injection layer usually contains a hole transporting compound and a solvent as a material for the hole injection layer. The hole transporting compound may be a low molecular compound or a high molecular compound as long as it is a compound having a hole transporting property, which is usually used for a hole injection layer of an organic electroluminescence device. . Moreover, you may form the positive hole injection layer 3 with a wet film-forming method using the organic electroluminescent element material of this invention which consists of a compound represented by said Formula (1) as a hole transportable compound.

  The hole transporting compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV from the viewpoint of a charge injection barrier from the anode 2 to the hole injection layer 3. Examples of hole transporting compounds include aromatic amine compounds, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, benzylphenyl compounds, compounds in which tertiary amines are linked by a fluorene group, hydrazone compounds, silazane compounds, silanamines Derivatives, phosphamine derivatives, quinacridone compounds, phthalocyanine derivatives, and the like.

  Of these, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred from the viewpoints of amorphousness and visible light transmittance. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine. The type of the aromatic tertiary amine compound is not particularly limited, but from the viewpoint of uniform light emission due to the surface smoothing effect, a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less (polymerized hydrocarbon compound in which repeating units are linked). Is more preferable. Preferable examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following general formula (I).

(In formula (I), Ar ^2A and Ar ^2B each independently represent an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar ^{3 to} Ar ⁵ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent aromatic heterocyclic group which may have a substituent. Y represents a linking group selected from the following linking group group, and two groups bonded to the same N atom among Ar ^2A , Ar ^2B , Ar ^{3 to} Ar ⁵ are bonded to each other. To form a ring.)

(In the above formulas, Ar ^{6 to} Ar ¹⁶ are each independently 1 derived from an aromatic hydrocarbon ring which may have a substituent, or an aromatic heterocyclic ring which may have a substituent. R ¹ and R ² each independently represents a hydrogen atom or an arbitrary substituent.

As Ar ^2A , Ar ^2B , Ar ^{3 to} Ar ¹⁶ , a monovalent or divalent group derived from any aromatic hydrocarbon ring or aromatic heterocyclic ring is applicable. These may be the same or different from each other. Moreover, you may have arbitrary substituents.

The group derived from the aromatic hydrocarbon ring and / or aromatic heterocycle of Ar ^2A , Ar ^2B , Ar ^{3 to} Ar ¹⁶ may further have a substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less.

Ar ^2A and Ar ^2B are preferably monovalent groups derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, and a pyridine ring from the viewpoint of the solubility, heat resistance, and hole injection / transport properties of the polymer compound. More preferred are a phenyl group and a naphthyl group.

In addition, as Ar ^{3 to} Ar ⁵ , a divalent group derived from a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring is preferable from the viewpoint of heat resistance and hole injection / transport properties including a redox potential. A group, a biphenylene group, and a naphthylene group are more preferable.

  Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the formula (I) include those described in the specification of International Publication No. 2005/089024.

  The hole transporting compound used as the material for the hole injection layer 3 may contain any one of these compounds alone, or may contain two or more. When two or more hole transporting compounds are contained, the combination thereof is arbitrary, but one or two or more aromatic tertiary amine polymer compounds and one or two other hole transporting compounds are used. It is preferable to use a seed or more in combination.

  The concentration of the hole transporting compound in the composition for forming a hole injection layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.01% by weight or more, preferably in terms of film thickness uniformity. Is 0.1% by weight or more, more preferably 0.5% by weight or more, and usually 70% by weight or less, preferably 60% by weight or less, more preferably 50% by weight or less. If the concentration of the hole transporting compound is too high, film thickness unevenness may occur, and if it is too low, defects may occur in the formed hole injection layer.

(Electron-accepting compound)
The composition for forming a hole injection layer preferably contains an electron accepting compound. The electron-accepting compound is preferably a compound having an oxidizing power and the ability to accept one electron from the above-described hole transporting compound, specifically, a compound having an electron affinity of 4 eV or more is preferable, and 5 eV or more. The compound which is the compound of these is further more preferable.

  The electron-accepting compound is selected from the group consisting of, for example, triarylboron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids. 1 type, or 2 or more types of compounds etc. which are mentioned. More specifically, an onium salt substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium tetrafluoroborate (WO 2005/089024) ); Iron (III) chloride (Japanese Patent Laid-Open No. 11-251067), high-valent inorganic compounds such as ammonium peroxodisulfate; Cyano compounds such as tetracyanoethylene, Tris (pendafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-31365) Aromatic boron compounds; fullerene derivatives; iodine and the like. One of these may be used alone, or two or more may be used in any combination and ratio.

  These electron-accepting compounds can improve the conductivity of the hole injection layer by oxidizing the hole transport material. The content of the electron-accepting compound with respect to the hole transport material is usually 0.1 mol% or more, preferably 1 mol% or more. However, it is usually 100 mol% or less, preferably 40 mol% or less.

(solvent)
At least one of the solvents used in the composition for forming a hole injection layer is preferably a compound that can dissolve the material for the hole injection layer.

  The boiling point of the solvent is usually 110 ° C. or higher, preferably 140 ° C. or higher, more preferably 200 ° C. or higher, usually 400 ° C. or lower, especially 300 ° C. or lower. If the boiling point of the organic solvent is too low, the drying speed is high and the film quality may be deteriorated. Moreover, when the boiling point of the organic solvent is too high, it is necessary to increase the temperature of the high drying step. Therefore, it may adversely affect other layers and the glass substrate.

  Suitable solvents for the hole injection layer forming composition include, for example, ether solvents, ester solvents, aromatic hydrocarbon solvents, amide solvents, and the like.

  Specifically, examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3- Examples include aromatic ethers such as dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

  Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

  Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-isopropylpropylphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene. Can be mentioned.

  Examples of the amide solvent include N, N-dimethylformamide and N, N-dimethylacetamide.

  In addition, dimethyl sulfoxide and the like can also be used.

  These solvent may use only 1 type and may use 2 or more types by arbitrary combinations and a ratio.

  Among the solvents described above, a solvent having a high ability to dissolve the material of the hole injection layer (dissolution ability) or a high affinity with the material is preferable. This is because a composition having a concentration excellent in the efficiency of the film forming step can be prepared by arbitrarily setting the concentration of the composition for forming the hole injection layer.

(Other things that may be included)
As a material for the hole injection layer, other components may be further contained in addition to the hole transporting compound and the electron accepting compound as long as the effects of the present invention are not significantly impaired. Examples of other components include various light emitting materials, electron transporting compounds, binder resins, and coating property improving agents. In addition, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

(Film formation method)
After preparing the composition for forming the hole injection layer using the components as described above, this composition is applied onto the layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2) by wet film formation. The hole injection layer 3 is formed by forming and drying.

  After the wet film formation, the film is usually dried by heating or the like. The heating means used in the heating step is not limited as long as the effects of the present invention are not significantly impaired. Examples of the heating means include a clean oven, a hot plate, infrared rays, a halogen heater, and microwave irradiation. Among them, a clean oven and a hot plate are preferable in order to uniformly apply heat to the entire film.

When forming the hole injection layer by a vacuum deposition method, one or more of the above-described materials for the hole injection layer (hole transporting compound, electron accepting compound, etc.) are placed in a vacuum container. Put in crucibles installed (in case of using two or more materials, put them in each crucible), evacuate the inside of the vacuum vessel to about 10 ⁻⁴ Pa with a suitable vacuum pump, then heat the crucible (two or more types) When using materials, heat each crucible) and control the amount of evaporation to evaporate (when using two or more materials, control the amount of evaporation independently) and place it facing the crucible. A hole injection layer 3 is formed on the anode 2 of the substrate. In addition, when using 2 or more types of materials, they can also be used for formation of the positive hole injection layer 3 by putting them in a crucible and carrying out heat evaporation.

  The thickness of the hole injection layer 3 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

<Hole transport layer>
The organic electroluminescent element of the present invention preferably has a hole transport layer 4, and the light emitting layer 5 described below is a layer formed by a wet film formation method using the composition for organic electroluminescent elements of the present invention. In this case, the ionization potential of the hole transport layer 4 is preferably −5.1 to −6.5 eV. By setting the ionization potential of the hole transport layer 4 within this range, the difference in ionization potential from the host material of the light emitting layer can be reduced, and hole injection into the light emitting layer can be performed more efficiently. This is because the organic electroluminescence device can be highly efficient and have a long life. Here, the ionization potential of the hole transport layer 4 refers to a value measured by a general measurement method using a commercially available apparatus such as photoelectron spectroscopy, atmospheric photoelectron spectroscopy, and cyclic voltammetry. Specifically, an organic thin film formed on a substrate such as a quartz plate or a slide glass to a thickness of about 100 nm by various film forming methods described later is measured by a general photoelectron spectroscopy in a vacuum. ,It is determined.

  Although there is no restriction | limiting in particular in the formation method of the positive hole transport layer 4 which concerns on this invention, It is preferable to form the positive hole transport layer 4 with a wet film-forming method from a viewpoint of dark spot reduction.

  The hole transport layer 4 can be formed on the hole injection layer when the device has a hole injection layer, and on the anode 2 when there is no hole injection layer.

  The material that can be used for forming the hole transport layer 4 is preferably a material that has high hole transportability and can efficiently transport injected holes. Therefore, it is preferable that the ionization potential is small, the transparency to visible light is high, the hole mobility is large, the stability is high, and impurities that become traps are not easily generated during manufacturing or use. In many cases, it is preferable not to quench the light emitted from the light emitting layer 5 or to form an exciplex with the light emitting layer 5 to reduce the efficiency because it is in contact with the light emitting layer 5.

  As a material of such a hole transport layer 4, what is necessary is just the material conventionally used as a material of a hole transport layer. Examples thereof include those exemplified as the hole transporting compound used for the hole injection layer 5 described above. In addition, two or more condensed aromatic rings including two or more tertiary amines represented by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl are substituted with nitrogen atoms. Aromatic amine compounds having a starburst structure (J. Lumin., J. Lumin., Etc.) such as aromatic diamines (Japanese Patent Laid-Open No. 5-234811) and 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine. 72-74, 985, 1997), aromatic amine compounds consisting of tetramers of triphenylamine (Chem. Commun., 2175, 1996), 2,2 ′, 7,7′-tetrakis- Spiro compounds such as (diphenylamino) -9,9'-spirobifluorene (Synth. Metals, 91, 209, 1997), 4,4'-N, N'-dicarbazole Carbazole derivatives such as phenyl and the like. Further, polyvinyl carbazole, polyvinyl triphenylamine (Japanese Patent Laid-Open No. 7-53953), polyarylene ether sulfone (Polym. Adv. Tech., 7, p. 33, 1996) containing tetraphenylbenzidine and the like can be mentioned. It is done.

  Moreover, you may form the positive hole injection layer 4 with a wet film-forming method using the organic electroluminescent element material of this invention which consists of a compound represented by said Formula (1) as a hole transportable compound.

  In the case of forming the hole transport layer 4 by a wet film formation method, a hole transport layer forming composition is prepared in the same manner as the formation of the hole injection layer 3 and then formed and heated and dried. The composition for forming a hole transport layer contains a solvent in addition to the hole transport compound. As this solvent, the same solvents as those exemplified as the solvent used in the composition for forming a hole injection layer can be used. The film forming conditions, heat drying conditions, and the like are the same as in forming the hole injection layer.

  When the hole transport layer 4 is formed by vacuum vapor deposition, the film forming conditions and the like are the same as in the case of forming the hole injection layer 3.

  The hole transport layer 4 may contain various light emitting materials, electron transport compounds, binder resins, coating property improving agents, and the like in addition to the hole transport compound.

  The hole transport layer 4 may be a layer formed by crosslinking a crosslinkable compound. Here, the crosslinkable compound is a compound having a crosslinking group, and forms a polymer by crosslinking. The crosslinkable compound may be any of a monomer, an oligomer, and a polymer. The crosslinkable compound may have only 1 type, and may have 2 or more types by arbitrary combinations and ratios.

  Examples of the crosslinking group of the crosslinking compound include cyclic ethers such as oxetane and epoxy; unsaturated double bonds such as vinyl group, trifluorovinyl group, styryl group, acrylic group, methacryloyl and cinnamoyl; benzocyclobutane and the like. It is done.

  The number of crosslinkable groups possessed by the crosslinkable compound, that is, the monomer, oligomer or polymer having a crosslinkable group is not particularly limited, but is generally less than 2.0, preferably 0.8 or less, more preferably 0 per unit charge transport unit. A number that is .5 or less is preferred. This is to adjust the relative dielectric constant of the hole transport layer forming material to a suitable range. Moreover, when the number of crosslinking groups is too large, reactive active species are generated, which may adversely affect other materials. Here, when the material forming the crosslinkable polymer is a monomer body, the unit charge transport unit is a monomer body itself, and indicates a skeleton (main skeleton) excluding a crosslinking group. Even when other types of monomers are mixed, the main skeleton of each monomer is shown. When the material forming the crosslinkable polymer is an oligomer or polymer, in the case of repeating a structure in which conjugation is broken organically, the repeated structure is defined as a unit charge transport unit. In the case of a structure in which conjugation is widely connected, a minimum repeating structure exhibiting charge transporting property or a monomer structure is shown. For example, polycyclic aromatics such as naphthalene, anthracene, phenanthrene, tetracene, chrysene, pyrene, perylene, fluorene, triphenylene, carbazole, triarylamine, tetraarylbenzidine, 1,4-bis (diarylamino) benzene, etc. It is done.

  Furthermore, as the crosslinkable compound, it is preferable to use a hole transporting compound having a crosslinkable group. Examples of hole transporting compounds in this case include nitrogen-containing aromatic compound derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives, phthalocyanine derivatives, porphyrin derivatives; Examples include phenylamine derivatives; silole derivatives; oligothiophene derivatives, condensed polycyclic aromatic derivatives, metal complexes, and the like. Among them, nitrogen-containing aromatic derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives; triphenylamine derivatives, silole derivatives, condensed polycyclic aromatic derivatives, metal complexes, etc. Particularly preferred are triphenylamine derivatives.

  The molecular weight of the crosslinkable compound is usually 5000 or less, preferably 2500 or less, preferably 300 or more, more preferably 500 or more.

  In order to form the hole transport layer 4 by crosslinking the crosslinkable compound, usually, a coating liquid (composition for forming a hole transport layer) in which the crosslinkable compound is dissolved or dispersed in a solvent is prepared, and wet film formation is performed. A film is formed by the method, and then the crosslinkable compound is crosslinked.

  In addition to the crosslinkable compound, this coating solution may contain an additive that accelerates the crosslinking reaction. Examples of additives that accelerate the crosslinking reaction include polymerization initiators and polymerization accelerators such as alkylphenone compounds, acylphosphine oxide compounds, metallocene compounds, oxime ester compounds, azo compounds, onium salts; condensed polycyclic hydrocarbons, And photosensitizers such as porphyrin compounds and diaryl ketone compounds. One of these may be used alone, or two or more may be used in any combination and ratio.

  Moreover, this coating liquid may further contain a coating property improving agent such as a leveling agent and an antifoaming agent, an electron accepting compound, a binder resin, and the like.

  The solvent used in this coating solution is the same as that exemplified as the solvent for forming the hole injection layer.

  In this coating solution, the crosslinkable compound is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, usually 50% by weight or less, preferably 20% by weight or less, Preferably it contains 10 weight% or less.

  After the coating liquid is formed on the layer corresponding to the lower layer of the hole transport layer 4, the crosslinkable compound is crosslinked and polymerized by heating and / or irradiation with active energy such as light. The heating method after film formation is not particularly limited, and examples thereof include heat drying and reduced pressure drying. The heating condition in the case of heat drying is usually 120 ° C. or higher, preferably 400 ° C. or lower. The heating time is usually 1 minute or longer, preferably 24 hours or shorter. The heating means is not particularly limited, and means such as placing a laminated body having a deposited layer on a hot plate or heating in an oven is used. For example, conditions such as heating on a hot plate at 120 ° C. or more for 1 minute or more can be used.

  In the case of crosslinking by irradiation with active energy such as light, a method of direct irradiation using an ultraviolet, visible or infrared light source such as an ultra high pressure mercury lamp, a high pressure mercury lamp, a halogen lamp or an infrared lamp, or the aforementioned light source is used. Examples include a mask aligner incorporated and a method of irradiation using a conveyor type light irradiation device. In active energy irradiation other than light, for example, there is a method of irradiation using a so-called microwave oven that irradiates a microwave generated by a magnetron. As the irradiation time, it is preferable to set conditions necessary for reducing the solubility of the film, but irradiation is usually performed for 0.1 seconds or longer, preferably 10 hours or shorter.

  Heating and irradiation of active energy such as light may be performed individually or in combination. When combined, the order of implementation is not particularly limited.

  The active energy irradiation including heating and light is preferably performed in an atmosphere containing no moisture such as a nitrogen gas atmosphere in order to reduce the amount of moisture contained in the layer and / or moisture adsorbed on the surface after implementation. For the same purpose, when combined with heating and / or irradiation with active energy such as light, it is particularly preferable to perform at least the process immediately before the formation of the light-emitting layer described below in an atmosphere containing no moisture such as a nitrogen gas atmosphere. .

  The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

<Light emitting layer>
The light emitting layer 5 in the organic electroluminescent element of the present invention is preferably formed by a wet film forming method using the organic electroluminescent element material of the present invention. Usually, it forms with said wet film-forming method using the composition for organic electroluminescent elements of this invention.

  The film formation temperature at the time of film formation is not limited, but in order to prevent film loss due to the occurrence of crystals and aggregation in the composition, it is preferably 10 ° C. or higher, more preferably 13 ° C. or higher, further preferably 16 ° C. or higher, Moreover, 50 degrees C or less is preferable and 40 degrees C or less is more preferable.

  The relative humidity during film formation is not limited, but is usually 0.01 ppm or more, preferably 0.05 ppm or more, more preferably 0.1 ppm or more, usually 80% or less, preferably 60% or less, more preferably 15% or less, More preferably, it is 1% or less, and particularly preferably 100 ppm or less. If the relative humidity is too small, it is difficult to control the film forming conditions, and a stable environment cannot be maintained. On the other hand, if it is too large, moisture adsorption on the light emitting layer may be affected.

  After film formation, it is usually dried by heating. Examples of the heating means include a clean oven, a hot plate, infrared rays, a halogen heater, and microwave irradiation. Among these, a clean oven and a hot plate are preferable in order to uniformly apply heat to the entire film.

  The heating direction in the heating step is not limited as long as the effects of the present invention are not significantly impaired. As an example of the heating direction, for example, a film formation substrate is mounted on a hot plate, and the coating film is heated through the hot plate, whereby the coating film is placed on the lower surface of the substrate (a substrate on which no organic layer is applied). A method of heating from the side), a method of heating the coating film from all directions, front, back, left, and right by placing the film formation substrate in a clean oven.

  The heating temperature in the heating step is not particularly limited as long as the effect of the present invention is not significantly impaired, but is usually 90 ° C. or higher, preferably 100 ° C. or higher, and usually 200 ° C. or lower, preferably 140 ° C. or lower. preferable. If the heating temperature is too high, components may diffuse into other layers, and if it is too low, the residual solvent may not be removed sufficiently. Moreover, when it is a mixed solvent in which 2 or more types of solvents are contained in the composition for organic electroluminescent elements, it is preferable that at least 1 type is heated at the temperature more than the boiling point of the solvent.

  The heating time in the heating step is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 15 minutes or more, more preferably 30 minutes or more, further preferably 1 hour or more, and preferably 6 hours or less, more preferably Is 3 hours or less, more preferably 2 hours or less. This heating makes it possible to sufficiently insolubilize the coating film. If the heating time is too long, the components of the other layers tend to diffuse, and if it is too short, sufficient homogeneity cannot be obtained.

  The thickness of the light emitting layer 5 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 3 nm or more, preferably 5 nm or more, and usually 200 nm or less, preferably 100 nm or less. If the thickness of the light emitting layer 5 is too thin, defects may occur in the light emitting layer 5, and if it is too thick, the driving voltage of the device may increase.

  When the light emitting layer is not formed using the composition for organic electroluminescent elements of the present invention, that is, when the material for organic electroluminescent elements of the present invention is used for other layers, the light emitting layer is a conventional organic electroluminescent element. It can be formed by the material and method used as the layer.

<Hole blocking layer>
A hole blocking layer 6 may be provided on the light emitting layer 5. The hole blocking layer 6 has a role of blocking holes moving from the anode 2 from reaching the cathode 9 and a role of efficiently transporting electrons injected from the cathode 9 toward the light emitting layer 5. Have

  The physical properties required for the material constituting the hole blocking layer 6 include high electron mobility, low hole mobility, a large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). Is high. Examples of the material of the hole blocking layer 6 satisfying such conditions include, for example, bis (2-methyl-8-quinolinolato), (phenolato) aluminum, bis (2-methyl-8-quinolinolato), (triphenylsilanolato). ) Mixed ligand complexes such as aluminum, metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, distyrylbiphenyl Derivatives such as styryl compounds (JP-A-11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole and other triazole derivatives ( JP-A-7-41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), etc. It is below. Further, a compound having at least one pyridine ring substituted at positions 2, 4, and 6 described in International Publication No. 2005-022962 is also preferable as a material for the hole blocking layer 6. In addition, the material of the hole-blocking layer 6 may use only 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

  There is no restriction | limiting in the formation method of the hole-blocking layer 6. FIG. Therefore, it can be formed by a wet film formation method, a vacuum deposition method, or other methods. A vacuum deposition method is preferred.

  The thickness of the hole blocking layer 6 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

<Electron transport layer>
An electron transport layer 7 may be provided between the cathode 8 and the light emitting layer 5. The electron transport layer 7 is provided for the purpose of further improving the light emission efficiency of the device, and efficiently transports electrons injected from the cathode 9 between the electrodes to which an electric field is applied in the direction of the light emitting layer 5. Formed from a compound capable of

  As the electron transporting compound used for the electron transport layer 7, usually, the electron injection efficiency from the cathode 9 or the electron injection layer 8 described later is high, and the injected electrons are transported efficiently with high electron mobility. A compound that can be used is used. Examples of the compound satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives , Distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compounds ( JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide , N-type zinc sulfide, n-type zinc Such as emissions of zinc, and the like. In addition, the material of the electron carrying layer 7 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  There is no restriction | limiting in the formation method of the electron carrying layer 7. FIG. Therefore, it can be formed by a wet film formation method, a vacuum deposition method, or other methods. A vacuum deposition method is preferred.

  The thickness of the electron transport layer 7 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

<Electron injection layer>
The electron injection layer 8 plays a role of efficiently injecting electrons injected from the cathode 9 into the light emitting layer 5. In order to perform electron injection efficiently, the material for forming the electron injection layer 8 is preferably a metal having a low work function.

  Examples of the material for forming the electron injection layer 8 include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. In this case, the thickness of the electron injection layer 8 is usually preferably 0.1 nm or more and 5 nm or less.

Furthermore, an organic electron transport compound represented by a metal complex such as a nitrogen-containing heterocyclic compound such as bathophenanthroline or an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium or rubidium ( (As described in JP-A-10-270171, JP-A-2002-1000047, JP-A-2002-1000048, etc.), it is possible to improve the electron injection / transport properties and achieve excellent film quality. preferable. Further, for example, an ultra-thin insulating film (0.1 to 5 nm) formed of lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), lithium oxide (Li ₂ O), cesium carbonate (II) (CsCO ₃ ), or the like. ) Is also an effective method for improving the efficiency of the device (Applied Physics Letters, 1997, Vol. 70, pp. 152; Japanese Patent Laid-Open No. 10-74586; IEEE Transactions on Electron Devices, 1997) , Vol. 44, pp. 1245; see SID 04 Digest, pp. 154, etc.).

  In this case, the film thickness is usually 5 nm or more, preferably 10 nm or more, and is usually 200 nm or less, preferably 100 nm or less.

  In addition, the material of the electron injection layer 8 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  There is no restriction | limiting in the formation method of the electron injection layer 8. FIG. Therefore, it can be formed by a wet film formation method, a vacuum deposition method, or other methods.

<Cathode>
The cathode 9 serves to inject electrons into the layer on the light emitting layer 5 side.

  As the material of the cathode 9, the material used for the anode 2 can be used. However, a metal having a low work function is preferable for efficient electron injection. For example, tin, magnesium, indium, A suitable metal such as calcium, aluminum, silver, or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy. In addition, the material of the cathode 9 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The film thickness of the cathode 9 is usually the same as that of the anode.

  Further, for the purpose of protecting the cathode made of a low work function metal, it is preferable to further stack a metal layer having a high work function and stable to the atmosphere because the stability of the device is increased. For this purpose, for example, metals such as aluminum, silver, copper, nickel, chromium, gold and platinum are used. In addition, these materials may be used only by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

<Other layers>
The organic electroluminescent element of the present invention may have another configuration without departing from the gist thereof. For example, as long as the performance is not impaired, an arbitrary layer other than the layers described above may be provided between the anode 2 and the cathode 9, for example, an electron blocking layer described below, Arbitrary layers may be omitted.

  The electron blocking layer is provided on the anode side of the light emitting layer 5 in contact with the light emitting layer 5 and blocks electrons moving from the light emitting layer 5 from reaching the hole transport layer 4 and the hole injection layer 3. Thus, the probability of recombination of holes and electrons in the light emitting layer 5 is increased, the excitons generated are confined in the light emitting layer 5, and the positive holes injected from the hole transport layer 4 and the hole injection layer 3. There is a role of efficiently transporting the holes in the direction of the light emitting layer. In particular, it is effective when a phosphorescent material or a blue light emitting material is used as the light emitting material.

  The characteristics required for the electron blocking layer include high hole transportability, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1). Furthermore, in the present invention, when the light emitting layer is produced by the wet film formation method using the composition for organic electroluminescence elements of the present invention, the electron blocking layer is also required to be compatible with the wet film formation. Examples of the material used for the electron blocking layer 8 include a copolymer of dioctylfluorene and triphenylamine typified by F8-TFB (described in International Publication No. 2004/084260). In addition, the material of an electron blocking layer may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  There is no restriction | limiting in the formation method of an electron blocking layer. Therefore, it can be formed by a wet film formation method, a vacuum deposition method, or other methods.

  Moreover, in the layer structure demonstrated above, it is also possible to laminate | stack components other than a board | substrate in reverse order. For example, in the case of the layer configuration of FIG. 1, other components are provided in order from the cathode on the substrate 1.

  Furthermore, it is also possible to constitute an organic electroluminescent element by laminating components other than the substrate between two substrates, at least one of which has transparency.

In addition, a structure in which a plurality of components (light emitting units) other than the substrate are stacked in a plurality of layers (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interface layer between the steps (between the light emitting units) (when the anode is ITO and the cathode is Al, these two layers), for example, a charge made of vanadium pentoxide (V ₂ O ₅ ) or the like. When a generation layer (Carrier Generation Layer: CGL) is provided, a barrier between steps is reduced, which is more preferable from the viewpoint of light emission efficiency and driving voltage.

  Furthermore, the organic electroluminescent device of the present invention may be configured as a single organic electroluminescent device, or may be applied to a configuration in which a plurality of organic electroluminescent devices are arranged in an array, and an anode and a cathode May be applied to a configuration in which are arranged in an XY matrix.

  In addition, each layer described above may contain components other than those described as the respective layer constituent materials unless the effects of the present invention are significantly impaired.

[Organic EL display]
The organic EL display of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic electroluminescent display of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.
For example, the organic EL display of the present invention is formed by a method as described in “Organic EL Display” (Ohm, published on August 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). can do.

[Organic EL lighting]
The organic EL illumination of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic EL illumination of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

[Synthesis Example 1]
<Synthesis of Intermediate 1>

  Under a nitrogen atmosphere, tetrakis (triphenylphosphine) palladium (0) (0) (to a solution of 1-pyreneboronic acid (29.8 g), 3-bromoiodobenzene (37.6 g) in toluene (200 ml) and ethanol (150 ml) at room temperature. 6.99 g), 2M aqueous sodium carbonate solution (150 ml) was added and refluxed for 8 and a half hours. After allowing to cool to room temperature, water was added to the reaction mixture, and the mixture was extracted with methylene chloride. The organic layer was washed with water and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was recrystallized from cyclohexane to obtain Intermediate 1 (36.5 g).

<Synthesis of Intermediate 2>

  Under a nitrogen atmosphere, a suspension of intermediate 1 (20 g), bis (pinacolato) diboron (17 g), and potassium acetate (18.7 g) in dimethyl sulfoxide (168 ml) was heated to 60 ° C. with stirring, and [1,1- Bis (diphenylphosphino) ferrocene] dichloropalladium (II) dichloromethane complex (1.37 g) was added, and the mixture was stirred at 80 ° C. for 4 and a half hours. After cooling to room temperature, water was added to the reaction mixture, and the precipitated crystals were filtered. The crystals collected by filtration were dissolved in toluene, dried over magnesium sulfate, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride mixed solution), and suspended and washed with cyclohexane to obtain Intermediate 2 (12.5 g).

<Synthesis of Intermediate 3>

  Under a nitrogen atmosphere, tetrakis (triphenylphosphine) was added to a suspension of 9-bromoanthracene (17.3 g), 2-biphenylboronic acid (20 g) in toluene (135 ml) and 1,2-dimethoxyethane (135 ml) at room temperature. Palladium (0) (3.11 g), 2M tripotassium phosphate aqueous solution (135 ml) were added, and the mixture was refluxed for 8 hours. After cooling to room temperature, water was added to the reaction mixture and extracted with toluene. The organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 7/1) to obtain Intermediate 3 (19.6 g).

<Synthesis of Intermediate 4>

  Under ice-cooling, N, N-dimethylformamide solution (25 ml) in N-bromosuccinimide (5.47 g) was added to N, N-dimethylformamide (100 ml) solution of Intermediate 3 (10.7 g) in the reaction system. The solution was added dropwise so that the temperature was in the range of 0 to 5 ° C., and stirred at room temperature for 9 hours. After completion of the reaction, the reaction mixture was poured into water, extracted with methylene chloride, dried over sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was recrystallized from methylene chloride / methanol to obtain Intermediate 4 (15.5 g).

<Synthesis of Compound A>

  Under a nitrogen atmosphere, a solution of intermediate 2 (2.40 g) and intermediate 4 (2.01 g) in toluene (24 ml) and ethanol (12 ml) at room temperature with tetrakis (triphenylphosphine) palladium (0) (0. 29 g) 2M aqueous sodium carbonate solution (6 ml) was added and refluxed for 10 hours. After cooling to room temperature, the reaction mixture was filtered, and the filtrate was extracted with chloroform. The organic layer was washed with 1N hydrochloric acid and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 3/1) and suspended and washed with ethanol to obtain Compound A (2.66 g).

Compound A was confirmed by DEI-MS (m / z = 606 (M ⁺ )).
This had a glass transition temperature of 125 ° C. and a weight loss starting temperature under a nitrogen stream of 460 ° C.

[Synthesis Example 2]
<Synthesis of Intermediate 5>

  To a solution of 1,2-dibromopyrene (3.01 g, 8.36 mmol), 2-naphthaleneboronic acid (1.41 g, 7.95 mmol) in toluene (42 ml) and ethanol (21 ml), 2M aqueous sodium carbonate solution (10. 5 ml) and bubbling with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (0.48 g, 0.42 mmol) was added thereto, and the mixture was stirred for 5 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 5 (1.15 g, 36%).

<Synthesis of Intermediate 6>

  Intermediate 5 (1.15 g, 2.82 mmol), bis (pinacolato) diboron (0.86 g, 3.39 mmol), potassium acetate (0.94 g, 9.6 mmol), dichlorobis (diphenylphosphino) ferrocene palladium (69 mg) , 0.085 mmol) of dimethyl sulfoxide (8.5 ml) was stirred at 80 ° C. for 16 hours. The reaction mixture was poured into water, and the precipitated crystals were filtered. The obtained crystals were dissolved in toluene, washed with purified water, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 6 (0.70 g, 55%).

<Synthesis of Intermediate 7>

  A solution of Intermediate 6 (0.70 g, 1.53 mmol), 3-bromo-1-iodobenzene (0.52 g, 1.84 mmol) in toluene (8 ml), ethanol (4 ml) in 2M aqueous sodium carbonate (2 ml) Was bubbled with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (89 mg, 0.077 mmol) was added thereto and stirred for 5 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 7 (552 mg, 75%).

<Synthesis of Compound B>

Intermediate 7 (548 mg, 1.13 mmol), 9- (2-biphenyl) -10-anthraceneboronic acid (509 mg, 1.36 mmol) in toluene (6 ml), ethanol (3 ml) in a solution of 2M aqueous sodium carbonate (1 0.5 ml) and bubbling with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (66 mg, 0.057 mmol) was added thereto, and the mixture was stirred for 5 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound B (582 mg, 70%).
Compound B was confirmed by DEI-MS (m / z = 732 (M ⁺ )).

[Synthesis Example 3]
<Synthesis of Intermediate 8>

  Under a nitrogen atmosphere, dehydrated cyclohexane suspension of bromopyrene (5.36 g, 90.2 mmol), bis (pinacolato) diboron (11.45 g, 45.1 mmol) (0.94 g, 9.6 mmol), di-μ- Add methoxobis (1,5-cyclooctadiene) diiridium (I) (956 mg, 1.44 mmol), 4,4′-di-tert-butyl-2,2′-dipyridyl (775 mg, 2.89 mmol). And stirred for 8 hours under reflux. Insoluble matter was filtered off, and the solvent of the filtrate was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 8 (8.55 g, 23%).

<Synthesis of Intermediate 9>

  To a solution of Intermediate 8 (5.0 g, 12.2 mmol), 1-iodonaphthalene (6.24 g, 24.6 mmol) in toluene (60 ml) and ethanol (30 ml) was added 2M aqueous sodium carbonate solution (15 ml). And bubbling with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (71 mg, 0.614 mmol) was added thereto, and the mixture was stirred for 9 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 9 (2.53 g, 51%).

<Synthesis of Intermediate 10>

  Under nitrogen atmosphere, a solution of intermediate 9 (2.53 g, 6.21 mmol) in dehydrated tetrahydrofuran (100 ml) was cooled to −78 ° C., and 1.55 M normal butyl lithium hexane solution (5 ml, 7.45 mmol) was added dropwise. did. The mixture was stirred at the same temperature for 1 hour, trimethyl boronate (1.94 g, 18.6 mmol) was added, the mixture was further stirred at −78 ° C. for 2 hours, and stirred at room temperature for 4 hours. The reaction mixture was poured into water, the pH was adjusted to 1 with 1N HCl, and the mixture was extracted with ethyl acetate. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 10 (1.76 g, 76%).

<Synthesis of Intermediate 11>

  A solution of Intermediate 10 (1.76 g, 4.72 mmol), 3-bromo-1-iodobenzene (1.60 g, 5.66 mmol) in toluene (24 ml) and ethanol (12 ml) in 2M aqueous sodium carbonate (6 ml) Was bubbled with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (273 mg, 0.236 mmol) was added thereto, and the mixture was stirred for 8 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 11 (1.85 g, 81%).

<Synthesis of Compound C>

Intermediate 11 (1.84 g, 3.80 mmol), 9- (2-biphenyl) -10-anthraceneboronic acid (1.71 g, 4.56 mmol) in toluene (20 ml), ethanol (10 ml) in a solution of 2M carbonic acid. Aqueous sodium solution (5 ml) was added and bubbled with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (220 mg, 0.190 mmol) was added thereto, and the mixture was stirred for 8 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound C (1.35 g, 49%).
Compound C was confirmed by DEI-MS (m / z = 732 (M ⁺ )).

[Synthesis Example 4]
<Synthesis of Intermediate 12>

  2M in a solution of 9-bromo-10-anthraceneboronic acid (5.0 g, 16.6 mmol), 2-bromo-1-iodobenzene (5.64 g, 19.9 mmol) in toluene (200 ml), ethanol (100 ml). Sodium carbonate aqueous solution (50 ml) was added, and nitrogen was bubbled for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (960 mg, 0.831 mmol) was added thereto, and the mixture was stirred for 8 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain Intermediate 12 (3.56 g, 52%).

<Synthesis of Compound D>

To a solution of 3- (1-pyrenyl) phenylboronic acid (2.94 g, 9.14 mmol), intermediate 12 (1.71 g, 4.15 mmol) in toluene (40 ml), ethanol (20 ml), 2M aqueous sodium carbonate solution ( 10 ml) and bubbling with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (239 mg, 0.207 mmol) was added thereto, and the mixture was stirred for 9 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound D (3.56 g, 52%).
Compound D was confirmed by DEI-MS (m / z = 806 (M ⁺ )).

[Synthesis Example 5]
<Synthesis of Intermediate 13>

  To a solution of 1-naphthylboronic acid (1.11 g, 6.4 mmol), 2-bromo-1-iodobenzene (2.39 g, 8.4 mmol) in toluene (32 ml), ethanol (16 ml), 2M aqueous sodium carbonate solution ( 8 ml) was added and bubbled with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (369 mg, 0.32 mmol) was added thereto, and the mixture was stirred for 5 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 13 (2.40 g, 66%).

<Synthesis of Intermediate 14>

  Under a nitrogen atmosphere, a solution of intermediate 13 (2.3 g, 8.2 mmol) in dehydrated tetrahydrofuran (20 ml) was cooled to −78 ° C. and a 1.66 M normal butyl lithium hexane solution (5.2 ml, 8.5 mmol). Was dripped. The mixture was stirred at the same temperature for 1 hour, trimethyl boronate (2.54 g, 24.5 mmol) was added, and the mixture was further stirred at −78 ° C. for 2 hours and then at room temperature for 3 hours. The reaction mixture was poured into water, the pH was adjusted to 1 with 1N HCl, and the mixture was extracted with ethyl acetate. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 14 (1.25 g, 61%).

<Synthesis of Intermediate 15>

  To a solution of intermediate 14 (1.24 g, 4.79 mmol), 9-bromoanthracene (881 mg, 3.42 mmol) in dimethoxyethane (13 ml), toluene (5 ml) was added 2M aqueous potassium phosphate (7 ml), Bubbling with nitrogen was performed for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (158 mg, 0.136 mmol) was added thereto, and the mixture was stirred for 11 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 15 (487 mg, 38%).

<Synthesis of Intermediate 16>

  To a solution of intermediate 15 (487 mg, 1.28 mmol) in N, N-dimethylformamide (5 ml), N-bromosuccinimide (228 mg 1.28 mmol) in N, N-dimethylformamide (6 ml) was added dropwise over 10 minutes. After completion of dropping, the mixture was stirred at room temperature for 4 hours and poured into water. The precipitated crystals were separated by filtration to obtain Intermediate 16 (455 mg, 77%).

<Synthesis of Compound E>

To a solution of Intermediate 16 (450 mg, 0.979 mmol), 3- (1-pyrenyl) phenylboronic acid (378 mg, 1.18 mmol) in toluene (10 ml), ethanol (4 ml) was added 2M aqueous sodium carbonate solution (2 ml). And bubbling with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (56 mg, 0.048 mmol) was added thereto, and the mixture was stirred for 7 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound E (418 mg, 65%).
Compound E was confirmed by DEI-MS (m / z = 656 (M ⁺ )).

[Synthesis Example 6]
<Synthesis of Intermediate 17>

  A solution of tertiary butylanthracene (5.0 g, 21.3 mmol) in N, N-dimethylformamide (200 ml) was added a solution of N-bromosuccinimide (3.99 g, 22.4 mmol) in N, N-dimethylformamide (50 ml). It was added dropwise over 20 minutes. After completion of dropping, the mixture was stirred at room temperature for 12 hours, poured into water, the separated oil layer was separated by decantation, and the aqueous layer was extracted with methylene chloride. The oil layer was dissolved in methylene chloride, combined with the previous extract, washed with purified water, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 17 (5.36 g, 80%).

<Synthesis of Intermediate 18>

  A solution of Intermediate 17 (5.30 g, 16.9 mmol), 3-bromo-1-iodobenzene (4.0 g, 20.3 mmol) in toluene (50 ml), ethanol (50 ml) in 2M aqueous sodium carbonate (25 ml) Was bubbled with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (585 mg, 0.51 mmol) was added thereto, and the mixture was stirred for 18 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain intermediate 18 (4.90 g, 75%).

<Synthesis of Intermediate 19>

  To a solution of intermediate 18 (4.87 g, 12.7 mmol) in N, N-dimethylformamide (53 ml) was added 20 N, N-dimethylformamide (12 ml) in N-bromosuccinimide (2.40 g, 13.3 mmol). It was added dropwise over a period of minutes. After completion of dropping, the mixture was stirred at room temperature for 3 hours, poured into water, and the precipitated crystals were filtered. The crystals were washed with 50% aqueous methanol solution to obtain Intermediate 19 (5.5 g, 94%).

<Synthesis of Compound F>

A solution of Intermediate 19 (5.49 g, 11.8 mmol), 3- (1-pyrenyl) phenylboronic acid (4.56 g, 14.2 mmol) in toluene (120 ml) and ethanol (60 ml) in 2M aqueous sodium carbonate ( 40 ml) and bubbling with nitrogen for 15 minutes. Tetrakis (triphenylphosphine) palladium (0) (270 mg, 0.23 mmol) was added thereto, and the mixture was stirred for 5 hours while gently refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, extracted with toluene, the organic layer was washed with water and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound F (5.90 g, 76%).
Compound F was confirmed by DEI-MS (m / z = 662 (M ⁺ )).

[Example 1]
An anode 2 is formed by patterning an indium tin oxide (ITO) transparent conductive film with a thickness of 150 nm on a glass substrate (sputtered film, sheet resistance 15 Ω) into a 2 mm wide stripe by a normal photolithography technique. Formed. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

  Aromatic amine polymer compound PB-1 (weight average molecular weight: 29400, number average molecular weight: 12600) having the following structure as a hole transporting compound, compound PI-1 having the following structure as an electron accepting compound, and ethyl benzoate as a solvent A hole injection layer forming composition containing was prepared. PB-1 and PI-1 were PB-1: PI-1 = 10: 4 by weight ratio, and the total concentration of PB-1 and PI-1 in the composition was 2% by weight. This composition was wet-formed by spin coating on the anode 2 at a spinner rotation speed of 1500 rpm and a spinner rotation time of 30 seconds. After the film formation, it was heated and dried at 260 ° C. for 180 minutes. The thin film of the uniform hole injection layer 3 with a film thickness of 30 nm was formed by the above operation.

A composition for forming a hole transport layer containing Compound HT-1 having the following structure as a hole transporting compound and toluene as a solvent was prepared. The concentration of Compound HT-1 in the composition was 0.4% by weight. This composition was formed into a wet film by spin coating on the hole injection layer 3 at a spinner rotation speed of 1500 rpm and a spinner rotation time of 30 seconds. After film formation, the film was heated at 230 ° C. for 60 minutes. The thin film of the uniform hole transport layer 4 with a film thickness of 20 nm was formed by the above operation.
The ionization potential of the hole transport layer was −5.27 eV.

  A composition for an organic electroluminescence device containing Compound A synthesized in Synthesis Example 1 as a material for an organic electroluminescence device, Compound D-1 having the following structure, and toluene was prepared as a composition used for forming a light emitting layer. Compound A and D-1 in the composition were in a weight ratio of compound A: D-1 = 10: 1, and the total concentration of compound A and D-1 in the composition was 0.75 wt%. This composition was wet-formed by spin coating on the hole transport layer 4 at a spinner rotation speed of 1500 rpm and a spinner rotation time of 30 seconds. After the film formation, it was heated and dried at 100 ° C. for 60 minutes. The thin film of the uniform light emitting layer 5 with a film thickness of 40 nm was formed by the above operation.

  On the obtained light-emitting layer 5, the compound HB-1 having the following structure as the hole blocking layer 6 is formed to have a film thickness of 10 nm by a vacuum deposition method, and then the compound ET-1 having the following structure as the electron transporting layer 7. Were sequentially laminated so as to have a film thickness of 30 nm.

  Thereafter, by the vacuum evaporation method, the ITO stripe as the anode 2 is formed so that lithium fluoride (LiF) has a thickness of 0.5 nm as the electron injection layer 8 and aluminum as the cathode 9 has a thickness of 80 nm. The stripes were stacked in a 2 mm width with an orthogonal shape.

  As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained.

  It was confirmed that blue light emission having an EL peak wavelength of 464 nm was obtained from this device. Table 1 summarizes the characteristics and driving lifetimes of the organic electroluminescent elements obtained in this example, Example 2 described later, and Comparative Examples 1 and 2.

[Comparative Example 1]
An organic electroluminescent element was obtained in the same manner as in Example 1 except that the compound E-2 having the following structure was used instead of the compound A.
It was confirmed that blue light emission having an EL peak wavelength of 470 nm was obtained from this device. Although this device had the same drive voltage as that of Example 1, the maximum luminance and efficiency were low, and the drive life was short.

[Example 2]
Organic as in Example 1 except that cyclohexylbenzene was used in place of toluene as the solvent contained in the composition for organic electroluminescent elements used in the light emitting layer, and the solid content concentration was changed to 2.3 wt%. An electroluminescent element was obtained.
It was confirmed that blue light emission having an EL peak wavelength of 467 nm was obtained from this device.

[Comparative Example 2]
An organic electroluminescent element was obtained in the same manner as in Example 2 except that the compound E-2 used in Comparative Example 1 was used instead of the compound A.
It was confirmed that blue light emission having an EL peak wavelength of 472 nm was obtained from this device. This device had a lower maximum luminance than that of Example 2, a high driving voltage, inferior current efficiency, a low color purity, and a short driving life.

[Example 3]
An organic electroluminescent element was obtained in the same manner as in Example 1 except that Compound B synthesized in Synthesis Example 2 was used instead of Compound A.
It was confirmed that blue light emission having an EL peak wavelength of 461 nm was obtained from this device.

[Example 4]
An organic electroluminescent element was obtained in the same manner as in Example 1 except that Compound D synthesized in Synthesis Example 4 was used instead of Compound A.
It was confirmed that blue light emission having an EL peak wavelength of 470 nm was obtained from this device.

[Example 5]
An organic electroluminescent element was obtained in the same manner as in Example 2 except that Compound E synthesized in Synthesis Example 5 was used instead of Compound A.
It was confirmed that blue light emission having an EL peak wavelength of 464 nm was obtained from this device.

<Element brightness half-life>
When the device of Example 1 and the device of Comparative Example 1 were made to emit light at 1000 cd / m ² under room temperature conditions, the time required for the front luminance to decrease to 50% of the initial luminance was 620 hours and 520 hours, respectively. Met.
Further, when the device of Example 2 and the device of Comparative Example 2 were made to emit light at 1000 cd / m ² under room temperature conditions, the time required for the front luminance to decrease to 50% of the initial luminance was 700 hours, respectively. It was 630 hours.

[Solubility test]
[Example 6]
Using the compound A of the present invention synthesized in Synthesis Example 1 and a comparative compound represented by the following formula (E-3), the solubility in an organic solvent (cyclohexylbenzene) was measured. Table 2 shows the measurement results.

  From the above, it can be seen that the compound of the present invention represented by the formula (1) is excellent in solubility in an organic solvent. As shown in Table 1, when an element is used, the film uniformity is excellent, so that a short circuit or a dark spot does not occur, and an element having a long driving life and high light emission efficiency is formed. That is, the organic electroluminescent element material of the present invention comprising the compound represented by the formula (1) has both solubility in an organic solvent and charge transportability.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Hole blocking layer 7 Electron transport layer 8 Electron injection layer 9 Cathode

Claims (7)

An organic electroluminescent element material, which is a material used for an organic layer formed by a wet film-forming method of an organic electroluminescent element, comprising a compound represented by the following formula (1).

(In formula (1), Ar ¹ represents an aromatic ring having 30 or less carbon atoms which may have a substituent. Ring A represents an aromatic ring having 30 or less carbon atoms which may have a substituent. , Ar ¹ is bonded to the ortho position with respect to the bonding position of the anthracene ring to ring A. L ¹ is an aromatic ring having 50 or less carbon atoms which may have a substituent or an atom formed by connecting aromatic rings. (The anthracene ring and pyrene ring to which L ¹ is bonded may have a substituent.) The organic electroluminescent element material according to claim 1, wherein the formula (1) is represented by the following formula (2).

(In the formula (2), Ar ¹ and ^{L 1} is an anthracene ring and pyrene ring .L ¹ is as defined as in the formula (1) are attached may have a substituent. In addition, Ar ¹ is (The benzene ring to be bonded may have a substituent.)   An organic electroluminescent element composition comprising the organic electroluminescent element material according to claim 1 or 2 and a solvent.   In the organic electroluminescence device having an organic layer between the anode and the cathode, at least one of the organic layers is a layer formed by wet deposition using the composition for organic electroluminescence device according to claim 3. An organic electroluminescent element characterized by the above.   The organic layer has a hole transport layer and a light emitting layer, the ionization potential of the hole transport layer is -5.1 to -6.5 eV, and the light emitting layer is composed of the composition for an organic electroluminescent element. The organic electroluminescent element according to claim 4, wherein the organic electroluminescent element is a layer formed by a wet process.   The organic electroluminescent display using the organic electroluminescent element of Claim 4 or 5.   Organic EL illumination using the organic electroluminescent element according to claim 4 or 5.

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