JP2018115151A - Triazine compound having benzimidazole group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a specific triazine compound that significantly improves the life properties and luminous efficiency of an organic electroluminescent element as compared to the well-known triazine compounds.SOLUTION: The present invention provides a triazine compound illustrated by the following formula, and an organic electroluminescent element containing the same as a component.SELECTED DRAWING: None

Description

  The present invention relates to a triazine compound useful as a component of an organic electroluminescent device, more specifically, a triazine compound characterized by having a benzimidazole group in the molecule, and an organic electroluminescent device material containing the same. is there.

  An organic electroluminescent element is formed by sandwiching a light-emitting layer containing a light-emitting material between a hole transport layer and an electron transport layer, and further attaching an anode and a cathode to the outside, and recombination of holes and electrons injected into the light-emitting layer. It is an element that utilizes light emission (fluorescence or phosphorescence) when the excitons that are generated are deactivated, and is applied not only to small displays but also to large televisions and lighting. The hole transport layer is divided into a hole transport layer and a hole injection layer, the light emitting layer is divided into an electron blocking layer, a light emitting layer and a hole blocking layer, and the electron transport layer is divided into an electron transport layer and an electron injection layer. May be configured. In some cases, a co-deposited film doped with a metal, an organometallic compound, or another organic compound may be used as the carrier transport layer (electron transport layer or hole transport layer) of the organic electroluminescence device.

  Conventional organic electroluminescent elements have higher driving voltage than inorganic light-emitting diodes, low luminance and luminous efficiency, and extremely low element lifetime, so that they have not been put to practical use in a wide range of fields. Recent organic electroluminescence devices are gradually improved with the above-mentioned drawbacks, and practical application has begun mainly for mobile applications.

  Examples of the material for the organic electroluminescent element include the triazine compound disclosed in Patent Document 1.

JP 2011-063584 A

  In order to expand applications other than mobile applications, performance improvement is essential, and materials with higher luminous efficiency characteristics and longer life characteristics are required. Patent Document 1 in the prior art also requires further improvement in terms of improvement in light emission efficiency and improvement in long life characteristics.

  As a result of intensive studies to solve the above problems, the present inventors used a triazine compound represented by the following general formula (1), which has a benzimidazole group, as an electron transport layer. It has been found that the organic electroluminescent element exhibits significantly higher luminous efficiency and longer life than when a conventionally known material is used, and the present invention has been completed.

  That is, the present invention relates to a triazine compound represented by the following general formula (1) (hereinafter referred to as triazine compound (1)) and an organic electroluminescence device containing the same.

(Where
Ar ¹ is the same and represents a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with an alkyl group having 1 to 4 carbon atoms).
Ar ² is a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a pyridyl group). , A phenyl group, a naphthyl group, or a biphenyl group), or a monocyclic or condensed nitrogen-containing aromatic group having 3 to 13 carbon atoms composed of only a 6-membered ring (the group is fluorine An atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group).
X ¹ represents a single bond or an arylene group having 4 to 14 carbon atoms (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a biphenyl group, or a naphthyl group). Represent.
R represents a kind of group selected from the following general formulas (2) to (4). )

(In the formula, Ar ³ and Ar ⁴ are each independently a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms). , May be substituted with an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group), or a monocyclic or condensed ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Ring nitrogen-containing aromatic group (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group) Represents good).)

  The present invention is based on the molecular structural feature of having a benzimidazole group represented by any one of the above general formulas (2) to (4), as compared with conventionally known triazine compounds. There is an effect that a person skilled in the art of remarkably improving the light emission efficiency and the lifetime characteristic cannot easily conceive. Moreover, this invention has an effect of providing the material for organic electroluminescent elements and organic electroluminescent element which were excellent in the luminous efficiency and long lifetime characteristic which use the triazine compound of this invention.

  When used as an electron transport layer, the triazine compound of the present invention can provide an organic electroluminescence device that is remarkably excellent in luminous efficiency and long life characteristics as compared with a conventionally known triazine compound.

  Hereinafter, the present invention will be described in detail.

  The present invention relates to a triazine compound represented by the general formula (1).

In the triazine compound represented by the general formula (1), Ar ¹ is the same, and a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with an alkyl group having 1 to 4 carbon atoms). ). Although it does not specifically limit as said naphthyl group, For example, 1-naphthyl group and 2-naphthyl group are mentioned. Among these, a 1-naphthyl group is preferable in terms of excellent organic electroluminescence device performance. In addition, the biphenyl group is not particularly limited, and examples thereof include 1,1′-biphenyl-2-yl group, 1,1′-biphenyl-3-yl group, and 1,1′-biphenyl-4. -An yl group is mentioned. Of these, a 1,1′-biphenyl-3-yl group is preferable in terms of excellent organic electroluminescence device performance. The alkyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, Or a t-butyl group etc. are mentioned. Among these, a methyl group is preferable in that the performance of the organic electroluminescent element is excellent.

That is, Ar ¹ is the same in terms of excellent lifetime of the organic electroluminescent device, and is a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with a methyl group). Are the same, more preferably a phenyl group, a naphthyl group, or a biphenyl group, and the same, a phenyl group, a 1-naphthyl group, or a 1,1′-biphenyl-3-yl group. More preferably, it is more preferably a phenyl group from the viewpoint of easy synthesis.

In the triazine compound represented by the general formula (1), Ar ² is a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms). , May be substituted with an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group), or a monocyclic or condensed ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Ring nitrogen-containing aromatic group (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group) Good). Although it does not specifically limit as said C6-C18 monocyclic, a connection, or a condensed-ring aromatic hydrocarbon group, For example, a phenyl group, a naphthyl group (for example, 1-naphthyl group, 2-naphthyl group) Phenanthryl group (for example, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group), anthryl group (for example, 1-anthryl group, 2-anthryl group, 9-anthryl group) Group), pyrenyl group (for example, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group), triphenylenyl group (for example, 1-triphenylenyl group, 2-triphenylenyl group), or fluoranthenyl group (for example, 1-pyrenyl group) Fluoranthenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 7-fluoranthenyl group, 8-fluoranthenyl group Ranteniru group). In addition, the monocyclic or condensed nitrogen-containing aromatic group having 3 to 13 carbon atoms composed of only the 6-membered ring is not particularly limited, and examples thereof include a pyridylphenyl group, a pyridylbiphenyl group, and a pyridylnaphthyl group. Group, pyridylphenanthryl group, pyridylanthryl group, pyridylpyrenyl group, pyridyltriphenylenyl group, pyridylcrisenyl group, pyridylfluoranthenyl group, pyridylacenaphthylenyl group, pyrimidylphenyl group, pyrimidyl group Biphenyl group, pyrimidylnaphthyl group, pyrimidyl phenanthryl group, pyrimidyl anthryl group, pyrimidyl pyrenyl group, pyrimidyl triphenylenyl group, pyrimidyl chrysenyl group, pyrimidyl fluoranthenyl Group, pyrimidyl acenaphthylenyl group, pyrazylphenyl group, pyrazylbiphenyl group, pyrazylnaphth Group, pyrazyl phenanthryl group, pyrazyl anthryl group, pyrazyl pyrenyl group, pyrazyl triphenylenyl group, pyrazyl chrysenyl group, pyrazyl fluoranthenyl group, pyrazyl acenaphthylenyl group, quinolyl phenyl Group, quinolylbiphenyl group, quinolylnaphthyl group, quinolylphenanthryl group, quinolylanthryl group, quinolylpyrenyl group, quinolyltriphenylenyl group, quinolylchrycenyl group, quinolylfluoranthenyl group, quinolylacena Futylenyl, isoquinolylphenyl, isoquinolylbiphenyl, isoquinolylnaphthyl, isoquinolylphenanthryl, isoquinolylanthryl, isoquinolylpyrenyl, isoquinolyltriphenylenyl Group, isoquinolyl chrysenyl group, isoquinolyl fluoranthenyl group, iso Noryl Asena border les group and the like. The alkyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, Or a t-butyl group etc. are mentioned. Among these, a methyl group is preferable in that the performance of the organic electroluminescent element is excellent. Although it does not specifically limit as said C1-C4 alkoxy group, For example, a methoxy group, an ethoxy group, 1-propoxy group, 2-propoxy group, 1-butoxy group, 2-butoxy group, or t -Butoxy group etc. are mentioned. Among these, a methoxy group is preferable in terms of excellent organic electroluminescence device performance.

Thus, Ar ² is excellent in the lifetime of the organic electroluminescent device, and is a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a triphenylenyl group, or a fluoranthenyl group. 1 to 4 alkyl groups may be substituted), more preferably a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a triphenylenyl group, or a fluoranthenyl group, Phenyl group, 1-naphthyl group, 2-naphthyl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-anthryl group, 2-anthryl group, 9- Anthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 1-triphenylenyl It is more preferably a group, 2-triphenylenyl group, 1-fluoranthenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 7-fluoranthenyl group, or 8-fluoranthenyl group.

X ¹ represents a single bond or an arylene group having 4 to 14 carbon atoms (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a biphenyl group, or a naphthyl group). Represent.

In the triazine compound represented by the general formula (1), X ¹ is a single bond or an arylene group having 4 to 14 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a biphenyl group, Or it may be substituted with a naphthyl group. An arylene group represents a divalent aromatic group, for example, a divalent aromatic hydrocarbon group or a divalent heteroaromatic group. The arylene group having 4 to 14 carbon atoms (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a biphenyl group, or a naphthyl group) is particularly limited. However, for example, phenylene group, fluorophenylene group, methylphenylene group, dimethylphenylene group, naphthylene group, fluoronaphthylene group, methylnaphthylene group, pyridylene group, fluoropyridylene group, methylpyridylene group, dimethylpyridylene group, Examples include pyrazylene group, fluoropyrazylene group, methylpyrazylene group, pyrimidylene group, fluoropyrimidylene group, methylpyrimidylene group, dimethylpyrimidylene group, phenylpyridylene group, naphthylpyridylene group, or biphenylpyridylene group. It is done. Although it does not specifically limit as said alkyl group of 1-4, For example, a methyl group, an ethyl group, 1-propyl group, 2-propyl group, 1-butyl group, 2-butyl group, or t-butyl Groups and the like. Among these, a methyl group is preferable in that the performance of the organic electroluminescent element is excellent.

X ¹ is a single bond or a phenylene group (this group is substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a biphenyl group, or a naphthyl group in terms of excellent lifetime of the organic electroluminescent device. It is preferable that it is a single bond in terms of easy synthesis.

  R represents a kind of group selected from the following general formulas (2) to (4).

(In the formula, Ar ³ and Ar ⁴ are each independently a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms). , May be substituted with an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group), or a monocyclic or condensed ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Ring nitrogen-containing aromatic group (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group) Represents good).)
The monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms is not particularly limited, and examples thereof include a phenyl group and a naphthyl group (for example, a 1-naphthyl group and a 2-naphthyl group). Phenanthryl group (for example, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group), anthryl group (for example, 1-anthryl group, 2-anthryl group, 9-anthryl group) Group), pyrenyl group (for example, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group), triphenylenyl group (for example, 1-triphenylenyl group, 2-triphenylenyl group), or fluoranthenyl group (for example, 1-pyrenyl group) Fluoranthenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 7-fluoranthenyl group, 8-fluoranthenyl group Nteniru group). In addition, the monocyclic or condensed nitrogen-containing aromatic group having 3 to 13 carbon atoms composed of only the 6-membered ring is not particularly limited, and examples thereof include a pyridylphenyl group, a pyridylbiphenyl group, and a pyridylnaphthyl group. Group, pyridylphenanthryl group, pyridylanthryl group, pyridylpyrenyl group, pyridyltriphenylenyl group, pyridylcrisenyl group, pyridylfluoranthenyl group, pyridylacenaphthylenyl group, pyrimidylphenyl group, pyrimidyl group Biphenyl group, pyrimidylnaphthyl group, pyrimidyl phenanthryl group, pyrimidyl anthryl group, pyrimidyl pyrenyl group, pyrimidyl triphenylenyl group, pyrimidyl chrysenyl group, pyrimidyl fluoranthenyl Group, pyrimidyl acenaphthylenyl group, pyrazylphenyl group, pyrazylbiphenyl group, pyrazylnaphthyl Group, pyrazyl phenanthryl group, pyrazyl anthryl group, pyrazyl pyrenyl group, pyrazyl triphenylenyl group, pyrazyl chrysenyl group, pyrazyl fluoranthenyl group, pyrazyl acenaphthylenyl group, quinolyl phenyl group Quinolylbiphenyl, quinolylnaphthyl, quinolylphenanthryl, quinolylanthryl, quinolylpyrenyl, quinolyltriphenylenyl, quinolylchrycenyl, quinolylfluoranthenyl, quinolylacenaphthyl Renyl, isoquinolylphenyl, isoquinolylbiphenyl, isoquinolylnaphthyl, isoquinolylphenanthryl, isoquinolylanthryl, isoquinolylpyrenyl, isoquinolyltriphenylenyl Group, isoquinolyl chrysenyl group, isoquinolyl fluoranthenyl group, or Etc. quinolyl Asena borderless les sulfonyl group. Moreover, although it does not specifically limit as said naphthyl group, For example, 1-naphthyl group and 2-naphthyl group are mentioned. The biphenyl group is not particularly limited, and examples thereof include 1,1′-biphenyl-2-yl group, 1,1′-biphenyl-3-yl group, and 1,1′-biphenyl-4-yl. Groups. The alkyl group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, and t. -A butyl group etc. are mentioned. Among these, a methyl group is preferable in that the performance of the organic electroluminescent element is excellent. Although it does not specifically limit as said C1-C4 alkoxy group, For example, a methoxy group, an ethoxy group, 1-propoxy group, 2-propoxy group, 1-butoxy group, 2-butoxy group, or t -Butoxy group etc. are mentioned. Among these, a methoxy group is preferable in terms of excellent organic electroluminescence device performance.

As for Ar ³ , a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with a fluorine atom or an alkyl group having 1 to 4 carbon atoms) in terms of excellent lifetime of the organic electroluminescent device. It is preferably a phenyl group, a naphthyl group, or a biphenyl group, and more preferably a phenyl group in terms of easy synthesis.

For Ar ⁴ , a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with a fluorine atom or an alkyl group having 1 to 4 carbon atoms) in terms of excellent lifetime of the organic electroluminescent device. It is preferably a phenyl group, a naphthyl group, or a biphenyl group, and more preferably a phenyl group in terms of easy synthesis.

  Moreover, about R, it is preferable that it is group represented by General formula (3) or (4) at the point which organic electroluminescent element performance is excellent.

  Specific examples of the triazine compound represented by the general formula (1) include the following (A-1) to (A-91), but the present invention is not limited thereto.

  The triazine compound represented by the general formula (1) of the present application is produced according to a generally known method using a generally known compound (for example, disclosed in JP-A-2008-280330), a reagent, and a generally known method. be able to.

  The triazine compound represented by the general formula (1) is not particularly limited, but is useful as a material for an organic electroluminescence device.

  Hereinafter, the organic electroluminescent element of the present invention will be described.

  In a broad sense, the light emitting layer in an organic electroluminescent element refers to a layer that emits light when a current is passed through an electrode composed of a cathode and an anode. Specifically, it refers to a layer containing a fluorescent compound that emits light when an electric current is passed through an electrode composed of a cathode and an anode. Usually, an organic electroluminescent element has a structure in which a light emitting layer is sandwiched between a pair of electrodes.

The organic electroluminescent device of the present invention has a hole transport layer, an electron transport layer, an anode buffer layer, a cathode buffer layer, etc. in addition to the light emitting layer as required, and has a structure sandwiched between a cathode and an anode. Specific examples include the structures shown below.
(I) Anode / light emitting layer / cathode (ii) Anode / hole transport layer / light emitting layer / cathode (iii) Anode / light emitting layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer / electron Transport layer / cathode (v) anode / anode buffer layer / hole transport layer / light emitting layer / electron transport layer / cathode buffer layer / cathode For the light emitting layer in the organic electroluminescent device of the present invention, a conventionally known light emitting material is used. be able to. As a method for forming the light emitting layer, for example, there is a method of forming a thin film by a known method such as a vapor deposition method, a spin coating method, a casting method, or an LB method.

  The light emitting layer can be obtained by dissolving a light emitting material in a solvent together with a binder such as a resin to form a solution, and then applying the solution by a spin coating method to form a thin film.

  There is no restriction | limiting in particular about the film thickness of the light emitting layer formed in this way, Although it can select suitably according to a condition, Usually, it is the range of 5 nm-5 micrometers.

  Next, other layers constituting the organic electroluminescence device in combination with the light emitting layer, such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer, will be described.

  The hole injection layer and the hole transport layer have a function of transmitting the holes injected from the anode to the light emitting layer, and the hole injection layer and the hole transport layer are interposed between the anode and the light emitting layer. Thus, many holes are injected into the light emitting layer with a lower electric field.

  In addition, electrons injected from the cathode and transported from the electron injection layer and / or the electron transport layer to the light-emitting layer are generated by the electron barrier existing at the interface between the light-emitting layer and the hole injection layer or the hole transport layer. It accumulates at the interface in the light emitting layer without leaking into the injection layer or the hole transport layer, resulting in an element with excellent light emitting performance such as improved luminous efficiency.

  The hole injection material and the hole transport material have any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. Examples of the hole injection material and hole transport material include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazoles. Derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers. As the hole injecting material and the hole transporting material, those described above can be used, and porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds, particularly aromatic tertiary amine compounds can be used. preferable.

  Representative examples of the aromatic tertiary amine compound and styrylamine compound include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl, N, N′-diphenyl-N, N ′. -Bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TPD), 2,2-bis (4-di-p-tolylaminophenyl) propane, 1,1- Bis (4-di-p-tolylaminophenyl) cyclohexane, N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl, 1,1-bis (4-di-p- Tolylaminophenyl) -4-phenylcyclohexane, bis (4-dimethylamino-2-methylphenyl) phenylmethane, bis (4-di-p-tolylaminophenyl) phenylmethane, N, N′-diphenyl-N, N -Di (4-methoxyphenyl) -4,4'-diaminobiphenyl, N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis (diphenylamino) quadri Phenyl, N, N, N-tri (p-tolyl) amine, 4- (di-p-tolylamino) -4 ′-[4- (di-p-tolylamino) styryl] stilbene, 4-N, N-diphenyl Amino- (2-diphenylvinyl) benzene, 3-methoxy-4′-N, N-diphenylaminostilbenzene, N-phenylcarbazole, 4,4′-bis [N- (1-naphthyl) -N-phenylamino ] Biphenyl (NPD), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) and the like. That.

  In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material. The hole injection layer and the hole transport layer are formed by thinning the hole injection material and the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. Can be formed. Although there is no restriction | limiting in particular about the film thickness of a positive hole injection layer and a positive hole transport layer, Usually, it is about 5 nm-5 micrometers. The hole injection layer and hole transport layer may have a single layer structure composed of one or more of the above materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

  In the organic electroluminescent element of the present invention, the electron transport layer preferably contains a triazine compound represented by the general formula (1).

  The electron transport layer may be formed by forming the triazine compound represented by the general formula (1) by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. it can. The thickness of the electron transport layer is not particularly limited, but is usually selected in the range of 5 nm to 5 μm. Further, this electron transport layer contains a triazine compound represented by the general formula (1), may contain a conventionally known electron transport material, and may have a single-layer structure composed of one kind or two or more kinds. Alternatively, a laminated structure composed of a plurality of layers having the same composition or different compositions may be used.

  In the present invention, the light emitting material is not limited to the light emitting layer, but may be contained in the hole transport layer or the electron transport layer adjacent to the light emitting layer. The luminous efficiency can be increased.

  The substrate that is preferably used in the organic electroluminescence device of the present invention is not particularly limited in the type of glass, plastic, and the like, and is not particularly limited as long as it is transparent. Examples of the substrate preferably used in the organic electroluminescence device of the present invention include glass, quartz, and a light transmissive plastic film.

  Examples of the light transmissive plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, and polycarbonate (PC). And a film made of cellulose triacetate (TAC), cellulose acetate propionate (CAP), or the like.

  A suitable example for producing the organic electroluminescent element of the present invention will be described. As an example, a method for producing an organic electroluminescent element composed of the anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.

  First, a thin film made of a desired electrode material, for example, an anode material, is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm. An anode is produced. Next, a thin film comprising a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer / electron injection layer, which is a device material, is formed thereon.

  A buffer layer (electrode interface layer) may exist between the anode and the light emitting layer or the hole injection layer and between the cathode and the light emitting layer or the electron injection layer.

  Furthermore, in addition to the basic constituent layer, a layer having other functions may be laminated as necessary. For example, a functional layer such as a hole blocking layer or an electron blocking layer may be provided.

Next, the electrode of the organic electroluminescent element of the present invention will be described. As the anode in the organic electroluminescent device, an electrode material made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a high work function (preferably 4 eV or more) is preferably used. Specific examples of such an electrode substance include a conductive transparent material such as a metal such as Au, CuI, indium-tin oxide (ITO), SnO ₂ , and ZnO.

  The anode may be formed by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by photolithography, or the pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering. May be formed.

On the other hand, as the cathode, those having an electrode substance of a metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof having a small work function (preferably 4 eV or less) are preferably used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this from the viewpoint of durability against electron injecting and oxidation, for example, a magnesium / silver mixture, magnesium An aluminum / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, and the like are preferable. The cathode can be produced by forming a thin film from these electrode materials by a method such as vapor deposition or sputtering.

  As described above, a thin film made of a desired electrode material, for example, an anode material, is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm. After preparing the anode, after forming each layer thin film consisting of the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer / electron injection layer on the anode as described above, for the cathode A thin film made of a substance is formed by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in a range of 50 to 200 nm, and a desired organic electroluminescent device is obtained.

  The organic electroluminescence device of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display). When used as a display device for reproducing moving images, the driving method may be either a simple matrix (passive matrix) method or an active matrix method. Moreover, it is possible to produce a full-color display device by using two or more organic electroluminescent elements of the present invention having different emission colors.

It is sectional drawing of the single layer element produced in the Example.

1. 1. Glass substrate with ITO transparent electrode 2. hole injection layer Charge generation layer 4. 4. Hole transport layer Light emitting layer 6. 6. Electron transport layer Cathode layer

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is limited and is not interpreted at all by these Examples.

¹ H-NMR measurement was performed using Gemini 200 (manufactured by Varian).

  The light emission characteristics of the organic electroluminescence device were evaluated by applying a direct current to the fabricated device at room temperature and using a luminance meter of LUMINANCEMETER (BM-9) (manufactured by TOPCON).

  Synthesis Example-1

  Under a nitrogen stream, 2- (3-bromo-5-chlorophenyl) -4,6-diphenyl-1,3,5-triazine (60.0 g, 0.142 mol), phenylboronic acid (22.5 g, 0.185 mol) ) And tetrakis (triphenylphosphine) palladium (3.28 g, 2.84 mmol) were suspended in 1,2-dimethoxyethane (600 mL), and the resulting suspension was suspended in 4.0 M sodium hydroxide aqueous solution (107 mL). , 0.426 mol). The resulting mixture was stirred at 80 ° C. for 5 hours. After allowing to cool, water (100 mL) was added, the precipitated solid was filtered off, and the solid was washed with water and methanol. By recrystallization (toluene), 2- (5-chloro-biphenyl-3-yl) -4,6-diphenyl-1,3,5-triazine white solid (yield 53.3 g, yield 89%) Got.

  Synthesis Example-2

  Under a nitrogen stream, 2- (5-chloro-biphenyl-3-yl) -4,6-diphenyl-1,3,5-triazine (3.00 g, 7.1 mmol) obtained in Synthesis Example-1 Spinacolato diboron (2.36 g, 9.3 mmol), palladium acetate (16.0 mg, 0.071 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl (68.2 mg, 0 .14 mmol) and potassium acetate (2.10 g, 21 mmol) were suspended in tetrahydrofuran (40 mL) and stirred at 65 ° C. for 6 hours. After allowing to cool, the precipitated components were removed by filtration. The filtrate was concentrated under reduced pressure and dried to obtain a crude product. Methanol was added and stirred and suspended while heating to 65 ° C., and the solid was collected by hot filtration. The obtained solid was dried under reduced pressure to give 2- [5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -biphenyl-3-yl] -4, A white powder of 6-diphenyl-1,3,5-triazine (yield 3.51 g, yield 96%) was obtained.

¹ H-NMR (CDCl ₃ ) δ (ppm): 1.43 (s, 12H), 7.51-7.75 (m, 10H), 7.82 (s, 1H), 7.89-7. 98 (m, 2H), 8.23 (brs, 1H), 8.75-8.81 (m, 5H), 8.83 (brd, J = 8.2 Hz, 1H), 9.01 (brs, 1H), 9.24 (brs, 1H).

  Synthesis example-3

2- (3-Bromo-5-chlorophenyl) -4,6-diphenyl-1,3 under nitrogen flow
, 5-triazine (40.0 g, 0.0946 mol), bispinacolatodiboron (28.8 g, 11.4 mmol)), and tetrakis (triphenylphosphine) palladium (3.28 g, 2.84 mmol) in tetrahydrofuran ( 600 mL) and stirred at 65 ° C. for 10 hours. After allowing to cool, the precipitated components were removed by filtration. The filtrate was concentrated under reduced pressure and dried to obtain a crude product. Methanol was added and stirred and suspended while heating to 65 ° C., and the solid was collected by hot filtration. The obtained solid was dried under reduced pressure to give 2- [3-chloro-5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl] -4,6- A white powder of diphenyl-1,3,5-triazine (yield 41.2 g, yield 93%) was obtained.

  Synthesis example 4

  2- [3-Chloro-5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl] -4, obtained in Synthesis Example-3 under a nitrogen stream 6-diphenyl-1,3,5-triazine (6.00 g, 12.8 mmol), 1- (4-bromophenyl) -2-phenylbenzimidazole (4.91 g, 14.0 mmol), tetrakis (triphenylphosphine) ) Palladium (0.443 g, 0.383 mmol) and 2M aqueous tripotassium phosphate solution (19.2 mL, 38.3 mmol) were suspended in tetrahydrofuran (130 mL) and stirred at 65 ° C. for 12 hours. After allowing to cool, the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water and methanol to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and 4,6-diphenyl-2- [3-chloro-5-{(2-phenylbenzimidazolyl-1-yl) -biphenyl-3, which was the target product, was obtained. -Il}]-1,3,5-triazine (yield 5.58 g, yield 71%, LC purity 99.52%) was obtained.

  Synthesis Example-1

  2- (5-Chloro-biphenyl-3-yl) -4,6-diphenyl-1,3,5-triazine (1.00 g, 2.38 mmol) obtained in Synthesis Example-1 under a nitrogen stream, 1 -Phenyl-2- [3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl] -benzimidazole (0.82 g, 2.62 mmol), palladium acetate ( 5.3 mg, 0.024 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl (22.7 mg, 0.048 mmol), and 2M aqueous tripotassium phosphate (3.57 mL, (7.14 mmol) was suspended in tetrahydrofuran (14 mL) and stirred at 65 ° C. for 5 hours. After allowing to cool, the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water and methanol to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and 4,6-diphenyl-2- [3- (1-phenylbenzimidazolyl-2-yl) -1,1 ′: 3 ′, the target product, was obtained. A gray powder (yield 1.09 g, yield 72%, LC purity 99.59%) of 1 ″ -terphenyl-5′-yl] -1,3,5-triazine (A-1) was obtained. The resulting compound had a Tg of 125 ° C.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.39-7.43 (m, 3H), 7.48 (s, 1H), 7.53 (t, J = 7.8 Hz, 5H), 7.58-7.62 (m, 8H), 7.67 (s, 1H), 7.74 (d, J = 8.9 Hz, 3H), 7.81 (t, J = 7.6 Hz, 2H) ), 7.89-7.94 (m, 2H), 8.79-8.84 (m, 5H), 8.94 (s, 1H).

  Synthesis Example-2

  2- (5-Chloro-biphenyl-3-yl) -4,6-diphenyl-1,3,5-triazine (1.00 g, 2.38 mmol) obtained in Synthesis Example-1 under a nitrogen stream, 4 -(1-phenyl-benzimidazol-2-yl) phenylboronic acid (1.04 g, 2.62 mmol), palladium acetate (5.3 mg, 0.024 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-Triisopropylbiphenyl (22.7 mg, 0.048 mmol) and 2M tripotassium phosphate aqueous solution (3.57 mL, 7.14 mmol) were suspended in tetrahydrofuran (15 mL) and stirred at 65 ° C. for 6 hours. After allowing to cool, the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water and methanol to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and the desired product 4,6-diphenyl-2- [4- (1-phenylbenzimidazolyl-2-yl) -1,1 ′: 3 ′, A gray powder (yield 1.10 g, yield 73%, LC purity 99.57%) of 1 ″ -terphenyl-5′-yl] -1,3,5-triazine (A-30) was obtained. The Tg of the obtained compound was 113 ° C.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.41-7.43 (m, 4H), 7.52-7.62 (m, 13H), 7.77-7.80 (m, 6H) ), 7.94 (d, J = 9.0, 1H), 8.03 (s, 1H), 8.80 (d, J = 6.6 Hz, 4H), 8.98 (s, 2H).

  Synthesis Example-3

  2- [5-{(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl} -biphenyl-3-yl obtained in Synthesis Example-2 under a nitrogen stream ] -4,6-diphenyl-1,3,5-triazine (1.50 g, 2.93 mmol), 1- (4-bromophenyl) -2-phenylbenzimidazole (1.13 g, 3.27 mmol), 4M Of sodium hydroxide (2.20 mL, 8.80 mmol) and tetrakis (triphenylphosphine) palladium (0.10 g, 0.088 mmol) were suspended in tetrahydrofuran (30 mL) and stirred at 65 ° C. for 8 hours. The resulting reaction solution was allowed to cool to room temperature, and the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water and methanol to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and the desired product, 4,6-diphenyl-2- [4- (2-phenylbenzimidazolyl-1-yl) -1,1 ′: 3 ′, A white powder (yield 1.17 g, 61% yield, LC purity 99.00%) of 1 ″ -terphenyl-5′-yl] -1,3,5-triazine (A-59) was obtained. The resulting compound had a Tg of 127 ° C.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.32-7.39 (m, 5H), 7.47-7.70 (m, 14H), 7.83 (d, J = 7.2 Hz) , 2H), 7.92-7.97 (m, 3H), 8.10 (s, 1H), 8.82 (d, J = 6.0 Hz, 4H), 9.04 (s, 2H).

  Synthesis Example 4

  4,6-Diphenyl-2- [3-chloro-5-{(2-phenylbenzimidazolyl-1-yl) -biphenyl-3-yl}]-1,3 obtained in Synthesis Example-3 under a nitrogen stream , 5-triazine (2.70 g, 4.41 mmol), 3-quinolineboronic acid (0.92 g, 5.29 mmol), palladium acetate (29.7 mg, 0.132 mmol), 2-dicyclohexylphosphino-2 ', 4', 6'-Triisopropylbiphenyl (12.6 mg, 0.027 mmol) and 2M aqueous tripotassium phosphate solution (6.62 mL, 13.2 mmol) were suspended in tetrahydrofuran (45 mL) at 65 ° C. Stir for 12 hours. After allowing to cool, the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water and methanol to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and 4,6-diphenyl-2- [4 ′-(2-phenylbenzimidazolyl-1-yl) -5- (3-quinolyl), which was the target product, was obtained. -Biphenyl-3-yl] -1,3,5-triazine (A-86) gray powder (yield 2.36 g, yield 76%, LC purity 99.99%) was obtained. The resulting compound had a Tg of 136 ° C.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.35-7.41 (m, 6H), 7.52-7.71 (m, 11H), 7.83 (t, J = 6.0 Hz) , 1H), 7.92-8.01 (m, 4H), 8.22-8.25 (m, 2H), 8.85 (s, 1H), 8.82 (d, J = 8.1 Hz). , 4H), 9.12 (s, H), 9.17 (s, H), 9.43 (s, H).

  Synthesis Example-5

  4,6-Diphenyl-2- [3-chloro-5-{(2-phenylbenzimidazolyl-1-yl) -biphenyl-3-yl}]-1,3 obtained in Synthesis Example-3 under a nitrogen stream , 5-triazine (2.70 g, 4.41 mmol), 2-phenyl-5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) pyridine (1.74 g, 6.18 mmol), palladium acetate (19.8 mg, 0.0882 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl (84.1 mg, 0.176 mmol), and 2M A tripotassium phosphate aqueous solution (6.62 mL, 13.2 mmol) was suspended in tetrahydrofuran (45 mL), and the mixture was stirred at 65 ° C. for 5 hours. After allowing to cool, the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water and methanol to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and 4,6-diphenyl-2- [4 ′-(2-phenylbenzimidazolyl-1-yl) -5- (6-phenyl- A gray powder (yield 1.02 g, yield 31.7%, LC purity 99.91%) of 3-pyridyl) -biphenyl-3-yl] -1,3,5-triazine (A-100) was obtained. . The resulting compound had a Tg of 139 ° C.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.36-7.70 (m, 19H), 7.95 (t, J = 7.2 Hz, 4H), 8.11-8.21 (m , 4H), 8.83 (d, J = 6.9 Hz, 4H), 9.10 (s, H), 9.11 (s, H), 9.20 (s, H).

  The structural formulas and abbreviations of the compounds used for device evaluation are shown below.

Element Example-1
As the substrate, a glass substrate with an ITO transparent electrode on which a 2 mm wide indium-tin oxide (ITO) film (film thickness 110 nm) was patterned in a stripe shape was used. The substrate was cleaned with isopropyl alcohol and then surface treated by ozone ultraviolet cleaning. Each layer was vacuum-deposited on the cleaned substrate by a vacuum deposition method, and an organic electroluminescence device having a light-emitting area of 4 mm ² as shown in FIG. Each organic material was formed by a resistance heating method.

First, the said glass substrate was introduce | transduced in the vacuum evaporation tank and it pressure-reduced to 1.0 * 10 <^-4> Pa.

  Thereafter, a hole injection layer 2, a charge generation layer 3, a hole transport layer 4, a light-emitting layer 5, an electron transport layer 6, and a cathode layer are formed as an organic compound layer on the glass substrate with an ITO transparent electrode shown by 1 in FIG. 7 were laminated in this order, and all were formed by vacuum deposition.

  As the hole injection layer 2, a sublimated HIL film having a thickness of 65 nm was formed at a rate of 0.15 nm / second.

  As the charge generation layer 3, sublimation-purified HAT was deposited to a thickness of 5 nm at a rate of 0.05 nm / second.

  As the hole transport layer 4, HTL was formed to a thickness of 10 nm at a rate of 0.15 nm / second.

  As the light emitting layer 5, EML-1 and EML-2 were formed to a thickness of 25 nm at a ratio of 95: 5 (weight ratio) (deposition rate of 0.18 nm / second).

  As the electron transport layer 6, 4,6-diphenyl-2- [3- (1-phenylbenzimidazolyl-2-yl) -1,1 ′: 3 ′, 1 ′ synthesized in Synthesis Example-1 of the present invention was used. '-Terphenyl-5'-yl] -1,3,5-triazine (Compound A-1) and Liq were deposited in a ratio of 50:50 (weight ratio) to a thickness of 30 nm (deposition rate: 0.15 nm / second) ).

  Finally, a metal mask was arranged so as to be orthogonal to the ITO stripe, and the cathode layer 7 was formed. The cathode layer 7 is formed of silver / magnesium (weight ratio 1/10) and silver in this order at 80 nm (film formation rate 0.5 nm / second) and 20 nm (film formation rate 0.2 nm / second), respectively. And it was set as the 2 layer structure.

  Each film thickness was measured with a stylus type film thickness meter (DEKTAK).

  Furthermore, this element was sealed in a nitrogen atmosphere glove box having an oxygen and moisture concentration of 1 ppm or less. For the sealing, a glass sealing cap and the above-described film-forming substrate epoxy type ultraviolet curable resin (manufactured by Nagase ChemteX Corporation) were used.

Element Example-2
4,6-Diphenyl-2- [4- (1-phenylbenzimidazolyl-2-yl) synthesized in Synthesis Example-2 instead of using Compound A-1 in the electron transport layer 6 of Device Example-1 -1,1 ′: 3 ′, 1 ″ -terphenyl-5′-yl] -1,3,5-triazine (Compound A-30) was used in the same manner as in Device Example-1. An organic electroluminescent element was prepared.

Element Example-3
4,6-diphenyl-2- [4- (2-phenylbenzimidazolyl-1-yl) synthesized in Synthesis Example-3 instead of using Compound A-1 in the electron transport layer 6 of Device Example-1. -1,1 ′: 3 ′, 1 ″ -terphenyl-5′-yl] -1,3,5-triazine (Compound A-59) was used in the same manner as in Device Example-1. An organic electroluminescent element was prepared.

Element Reference Example-1
In the electron transport layer 6 of device example-1, 4,6-diphenyl-2- [5 synthesized with reference to Patent Document-1 (Japanese Patent Laid-Open No. 2011-063584) instead of using Compound A-1. An organic electroluminescent device was produced in the same manner as in Device Example 1 except that-(9-anthryl) -biphenyl-3-yl] -1,3,5-triazine (Compound ETL-1) was used.

A direct current was applied to the produced organic electroluminescence device, and the light emission characteristics were evaluated using a luminance meter of LUMINANCE METER (BM-9) manufactured by TOPCON. As the light emission characteristics, the voltage (V) and current efficiency (cd / A) when a current density of 10 mA / cm ² was passed were measured, and the device lifetime during continuous lighting was measured. Note that the element lifetime, after which the initial luminance and the luminance was measured decay time at the time of continuous lighting when driven at 1000 cd / m ^2, the luminance (cd / m ²⁾ was measured the time taken for reducing 25% Thus, in the element reference example-1, the time required until the luminance (cd / m ² ) is reduced by 25% is expressed as a relative value with respect to 100. The results are shown below.

  From Table 1, it was found that the organic electroluminescent device using the azine compound of the present invention is remarkably superior in light emission efficiency and device lifetime as compared with the reference example.

  The present invention provides a novel triazine compound that can be used as an electron transport layer of an organic electroluminescence device to enable high efficiency and long life of the device, and further includes a low voltage using the compound. An organic electroluminescent device is provided.

Claims (13)

A triazine compound represented by the general formula (1).

(Where
Ar ¹ is the same and represents a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with an alkyl group having 1 to 4 carbon atoms).
Ar ² is a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a pyridyl group). , A phenyl group, a naphthyl group, or a biphenyl group), or a monocyclic or condensed nitrogen-containing aromatic group having 3 to 13 carbon atoms composed of only a 6-membered ring (the group is fluorine An atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group).
X ¹ represents a single bond or an arylene group having 4 to 14 carbon atoms (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a biphenyl group, or a naphthyl group). Represent.
R represents a kind of group selected from the following general formulas (2) to (4). )

(In the formula, Ar ³ and Ar ⁴ are each independently a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom, an alkyl group having 1 to 4 carbon atoms). , Which may be substituted with an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group), or a monocyclic or condensed ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Ring nitrogen-containing aromatic group (this group may be substituted with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a pyridyl group, a phenyl group, a naphthyl group, or a biphenyl group) Represents good).) The triazine compound according to claim 1, wherein Ar ¹ is the same and is a phenyl group, a naphthyl group, or a biphenyl group. The triazine compound according to claim 1 or 2, wherein Ar ¹ is a phenyl group. Ar ² is a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a triphenylenyl group, or a fluoranthenyl group (these groups may be substituted with an alkyl group having 1 to 4 carbon atoms). The triazine compound according to any one of claims 1 to 3. The triazine compound according to any one of claims 1 to 4, wherein Ar ² is a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a triphenylenyl group, or a fluoranthenyl group. Ar ² is phenyl group, 1-naphthyl group, 2-naphthyl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-anthryl group, 2-anthryl group Group, 9-anthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 1-triphenylenyl group, 2-triphenylenyl group, 1-fluoranthenyl group, 2-fluoranthenyl group, 3-fluorane The triazine compound according to any one of claims 1 to 5, which is a tenenyl group, a 7-fluoranthenyl group, or an 8-fluoranthenyl group. The triazine compound according to any one of claims 1 to 6, wherein Ar ³ is a phenyl group, a naphthyl group, or a biphenyl group. The triazine compound according to any one of claims 1 to 7, wherein Ar ³ is a phenyl group. The triazine compound according to any one of claims 1 to 8, wherein Ar ⁴ is a phenyl group, a naphthyl group, or a biphenyl group. The triazine compound according to any one of claims 1 to 9, wherein Ar ⁴ is a phenyl group. The triazine compound according to any one of claims 1 to 10, wherein X ¹ is a single bond.   An organic electroluminescent element material comprising the triazine compound according to claim 1.   An electron transport material for an organic electroluminescent device comprising the triazine compound according to claim 1.

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