JP6977567B2 - Triazine compound with benzimidazole group - Google Patents

Description

The present invention relates to a triazine compound useful as a constituent component of an organic electroluminescent element, more particularly to a triazine compound characterized by having a benzimidazole group in the molecule, and a material for an organic electroluminescent element containing the triazine compound. be.

In an organic electroluminescent element, a light emitting layer containing a light emitting material is sandwiched between a hole transport layer and an electron transport layer, an anode and a cathode are attached to the outside thereof, and holes and electrons injected into the light emitting layer are recombined. It is an element that utilizes the emission of light (fluorescence or phosphorescence) when the generated excitators 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 block layer, a light emitting layer and a hole block layer, and the electron transport layer is divided into an electron transport layer and an electron injection layer. It may be configured. Further, as the carrier transport layer (electron transport layer or hole transport layer) of the organic electroluminescent element, a co-deposited film doped with a metal, an organic metal compound or another organic compound may be used.

Conventional organic electroluminescent devices have a higher drive voltage, lower light emission brightness and light emission efficiency, and a significantly shorter device life than inorganic light emitting diodes, and have not been put into practical use in a wide range of fields. Recent organic electroluminescent devices have gradually improved the above-mentioned drawbacks, and have begun to be put into practical use mainly for mobile applications.

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

Japanese Unexamined Patent Publication No. 2011-063584

Performance improvement is indispensable for expanding applications other than mobile applications, and materials with higher luminous efficiency characteristics and long life characteristics are required. Patent Document 1 in the prior art is also required to be further improved in terms of improvement of luminous efficiency and improvement of long life characteristics.

As a result of diligent studies to solve the above problems, the present inventors have used a triazine compound represented by the following general formula (1), which is characterized by having 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 as compared with the case of using a conventionally known material, and has completed the present invention.

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 electroluminescent element containing the triazine compound (hereinafter referred to as triazine compound (1)).

(During the ceremony,
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 ring nitrogen-containing aromatic group consisting of only a 6-membered ring and having 3 to 13 carbon atoms (the group is fluorine). It may be substituted with 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 is a single bond or an arylene group having 4 to 14 carbon atoms (the 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). show.
R represents a kind of group selected from the following general formulas (2) to (4). )

(In the formula, Ar ³ and Ar ⁴ are independently monocyclic, linked or condensed aromatic hydrocarbon groups having 6 to 18 carbon atoms (the group is a fluorine atom and 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 ring or a shrunken ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Even if the ring-containing nitrogen-containing aromatic group is 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).)

The present invention is based on the molecular structural feature of having a benzimidazole group represented by any of the above general formulas (2) to (4), and is compared with a conventionally known triazine compound to an organic electric field luminous element. It has an effect that cannot be easily conceived by those skilled in the art, that is, the luminous efficiency and the life characteristics are remarkably improved. Further, the present invention has an effect of providing a material for an organic electroluminescent element and an organic electroluminescent element having excellent luminous efficiency and long life characteristics, which are made by using the triazine compound of the present invention.

The triazine compound of the present invention can provide an organic electroluminescent element which is remarkably superior in luminous efficiency and long life characteristics as compared with a conventionally known triazine compound when used as an electron transport layer.

Hereinafter, the present invention will be described in detail.

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

In the triazine compound represented by the general formula (1), Ar ¹ is the same and may be substituted with 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. ). The naphthyl group is not particularly limited, and examples thereof include a 1-naphthyl group and a 2-naphthyl group. Of these, the 1-naphthyl group is preferable because the organic electroluminescent device has excellent performance. The biphenyl group is not particularly limited, but for example, 1,1'-biphenyl-2-yl group, 1,1'-biphenyl-3-yl group, 1,1'-biphenyl-4. -Il group is mentioned. Of these, the 1,1'-biphenyl-3-yl group is preferable because the organic electroluminescent device has excellent performance. The alkyl group having 1 to 4 carbon atoms is not particularly limited, but for example, a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, and the like. Alternatively, a t-butyl group or the like can be mentioned. Of these, the methyl group is preferable because the organic electroluminescent device has excellent performance.

That is, Ar ¹ is the same in that it is excellent in the life of the organic electric field light emitting element, and is a phenyl group, a naphthyl group, or a biphenyl group (these groups may be substituted with a methyl group). Is more preferably the same, more preferably a phenyl group, a naphthyl group, or a biphenyl group, and more preferably the same, with a phenyl group, a 1-naphthyl group, or a 1,1'-biphenyl-3-yl group. It is more preferable to have a phenyl group, and it is further preferable to have a phenyl group because it is easy to synthesize.

In the triazine compound represented by the general formula (1), Ar ² is a monocyclic, linked or condensed ring aromatic hydrocarbon group having 6 to 18 carbon atoms (the group is a fluorine atom and 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 ring or a shrunken ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Even if the ring-containing nitrogen-containing aromatic group is 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). The monocyclic, linked or condensed ring aromatic hydrocarbon group having 6 to 18 carbon atoms is not particularly limited, and is, for example, a phenyl group or a naphthyl group (for example, a 1-naphthyl group or a 2-naphthyl group). , Phenyltril group (eg, 1-phenanthryl group, 2-phenanthril group, 3-phenanthril group, 4-phenanthril group, 9-phenanthril group), anthryl group (eg, 1-anthryl group, 2-anthryl group, 9-anthryl group). Group), pyrenyl group (eg, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group), triphenylenyl group (eg, 1-triphenylenyl group, 2-triphenylenyl group), or fluoranthenyl group (eg, 1-). Examples thereof include a fluoranthenyl group, a 2-fluoranthenyl group, a 3-fluoranthenyl group, a 7-fluoranthenyl group, and an 8-fluoranthenyl group). The monocyclic or condensed ring nitrogen-containing aromatic group having only the 6-membered ring and having 3 to 13 carbon atoms is not particularly limited, but is not particularly limited, and is, for example, a tolyl phenyl group, a tolyl biphenyl group, or a tolyl naphthyl. Group, pyridylphenanthril group, pyridylanthril group, pyridylpyrenyl group, pyridyltriphenylenyl group, pyridylcrisenyl group, pyridylfluoranthenyl group, pyridylacenaftyrenyl group, pyrimidylphenyl group, pyrimidyl Biphenyl group, pyrimidylnaphthyl group, pyrimidylphenanthril group, pyrimidylanthril group, pyrimidylpyrenyl group, pyrimidyltriphenylenyl group, pyrimidylcrisenyl group, pyrimidylfluoranthenyl Group, pyrimidyl acenaftylenyl group, pyrazilphenyl group, pyrazilbiphenyl group, pyrazilnaphthyl group, pyrazilfenantril group, pyrazil anthryl group, pyrazilpyrenyl group, pyraziltriphenylenyl group, pyragil Chrysenyl group, pyrazil fluoranthenyl group, pyrazil acenaphthylenyl group, quinolylphenyl group, quinolyl biphenyl group, quinolyl naphthyl group, quinolyl phenanthril group, quinolyl anthril group, quinolyl pyrenyl group, quino Liltriphenylenyl group, quinolylcrisenyl group, quinolylfluoranthenyl group, quinolyl acenaftylenyl group, isoquinolylphenyl group, isoquinolyl biphenyl group, isoquinolyl naphthyl group, isoquinolylfe Nantril group, isoquinolyl anthryl group, isoquinolyl pyrenyl group, isoquinolyl triphenylenyl group, isoquinolyl chrysenyl group, isoquinolyl fluoranthenyl group, isoquinolyl acenafutylenyl group And so on. The alkyl group having 1 to 4 carbon atoms is not particularly limited, but for example, a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, and the like. Alternatively, a t-butyl group or the like can be mentioned. Of these, the methyl group is preferable because the organic electroluminescent device has excellent performance. The alkoxy group having 1 to 4 carbon atoms is not particularly limited, and is, for example, a methoxy group, an ethoxy group, a 1-propoxy group, a 2-propoxy group, a 1-butoxy group, a 2-butoxy group, or t. -Butoxy groups and the like can be mentioned. Of these, the methoxy group is preferable because it is excellent in the performance of the organic electroluminescent device.

As described above, Ar ² has a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a triphenylenyl group, or a fluoranthenyl group (these groups have carbon atoms) in that Ar 2 has an excellent life of the organic electric field light emitting element. It may be substituted with 1 to 4 alkyl groups), 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 group, 2-triphenylenyl group, 1-fluoranthenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 7 More preferably, it is a −fluoranthenyl group or an 8-fluoranthenyl group.

X ¹ is a single bond or an arylene group having 4 to 14 carbon atoms (the 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). show.

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, and the like. Alternatively, it may be substituted with a naphthyl group). The 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 (the 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, a phenylene group, a fluorophenylene group, a methylphenylene group, a dimethylphenylene group, a naphthylene group, a fluoronaphthylene group, a methylnaphthylene group, a pyridylene group, a fluoropyridylene group, a methylpyridylene group, a dimethylpyridylene group, Pyrazilen group, fluoropyrazylene group, methylpyrazylene group, pyrimidirene group, fluoropyrimidilen group, methylpyrimidilen group, dimethylpyrimidilen group, phenylpyridylene group, naphthylpyridylene group, biphenylpyridylene group and the like can be mentioned. Be done. The alkyl groups 1 to 4 are not particularly limited, but for example, 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. Group etc. can be mentioned. Of these, the methyl group is preferable because the organic electroluminescent device has excellent performance.

Regarding X ¹ , a single bond or a phenylene group (the 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 that the life of the organic electric field light emitting element is excellent. It is preferable that it is a single bond, and it is more preferable that it is a single bond because it is easy to synthesize.

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

(In the formula, Ar ³ and Ar ⁴ are independently monocyclic, linked or condensed aromatic hydrocarbon groups having 6 to 18 carbon atoms (the group is a fluorine atom and 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 ring or a shrunken ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Even if the ring-containing nitrogen-containing aromatic group is 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).)
The monocyclic, linked or condensed ring aromatic hydrocarbon group having 6 to 18 carbon atoms is not particularly limited, and is, for example, a phenyl group or a naphthyl group (for example, a 1-naphthyl group or a 2-naphthyl group). , Phenyltril group (eg, 1-phenanthryl group, 2-phenanthril group, 3-phenanthril group, 4-phenanthril group, 9-phenanthril group), anthryl group (eg, 1-anthryl group, 2-anthryl group, 9-anthryl group). Group), pyrenyl group (eg, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group), triphenylenyl group (eg, 1-triphenylenyl group, 2-triphenylenyl group), or fluoranthenyl group (eg, 1-). Examples thereof include a fluoranthenyl group, a 2-fluoranthenyl group, a 3-fluoranthenyl group, a 7-fluoranthenyl group, and an 8-fluoranthenyl group). Further, the monocyclic or condensed ring nitrogen-containing aromatic group having only the 6-membered ring and having 3 to 13 carbon atoms is not particularly limited, and is, for example, a tolyl phenyl group, a tolyl biphenyl group, or a tolyl naphthyl. Group, pyridylphenanthril group, pyridylanthril group, pyridylpyrenyl group, pyridyltriphenylenyl group, pyridylcrisenyl group, pyridylfluoranthenyl group, pyridylacenaftyrenyl group, pyrimidylphenyl group, pyrimidyl Biphenyl group, pyrimidylnaphthyl group, pyrimidylphenanthril group, pyrimidylanthril group, pyrimidylpyrenyl group, pyrimidyltriphenylenyl group, pyrimidylcrisenyl group, pyrimidylfluoranthenyl Group, pyrimidyl acenaftylenyl group, pyrazilphenyl group, pyrazilbiphenyl group, pyrazilnaphthyl group, pyrazilfenantril group, pyrazil anthryl group, pyrazilpyrenyl group, pyraziltriphenylenyl group, pyragil Chrysenyl group, pyrazil fluoranthenyl group, pyrazil acenaphthylenyl group, quinolylphenyl group, quinolyl biphenyl group, quinolyl naphthyl group, quinolyl phenanthril group, quinolyl anthril group, quinolyl pyrenyl group, quino Liltriphenylenyl group, quinolylcrisenyl group, quinolylfluoranthenyl group, quinolyl acenaftylenyl group, isoquinolylphenyl group, isoquinolyl biphenyl group, isoquinolyl naphthyl group, isoquinolylfe Nantril group, isoquinolyl anthryl group, isoquinolyl pyrenyl group, isoquinolyl triphenylenyl group, isoquinolyl chrysenyl group, isoquinolyl fluoranthenyl group, or isoquinolyl acenaftylenyl The basis etc. can be mentioned. The naphthyl group is not particularly limited, and examples thereof include a 1-naphthyl group and a 2-naphthyl group. The biphenyl group is not particularly limited, but for example, 1,1'-biphenyl-2-yl group, 1,1'-biphenyl-3-yl group, 1,1'-biphenyl-4-yl group. The group is mentioned. The alkyl group having 1 to 4 carbon atoms is not particularly limited, but is, for example, a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, or t. -Butyl group and the like can be mentioned. Of these, the methyl group is preferable because the organic electroluminescent device has excellent performance. The alkoxy group having 1 to 4 carbon atoms is not particularly limited, and is, for example, a methoxy group, an ethoxy group, a 1-propoxy group, a 2-propoxy group, a 1-butoxy group, a 2-butoxy group, or t. -Butoxy groups and the like can be mentioned. Of these, the methoxy group is preferable because it is excellent in the performance of the organic electroluminescent device.

Regarding 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 that the life of the organic electric field light emitting element is excellent. It is more preferable that it is a phenyl group, a naphthyl group, or a biphenyl group, and it is more preferable that it is a phenyl group in that it is easy to synthesize.

Regarding 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 that the life of the organic electric field light emitting element is excellent. It is more preferable that it is a phenyl group, a naphthyl group, or a biphenyl group, and it is more preferable that it is a phenyl group in that it is easy to synthesize.

Further, with respect to R, it is preferable to have a group represented by the general formula (3) or (4) in that the organic electroluminescent device 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 electroluminescent device.

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

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

The organic electroluminescent element of the present invention has a hole transport layer, an electron transport layer, an anode buffer layer, a cathode buffer layer and the like in addition to a light emitting layer, if necessary, and has a structure sandwiched between a cathode and an anode. Specifically, the structure shown below can be mentioned.
(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 A conventionally known light emitting material is used for the light emitting layer in the organic electroluminescent element of the present invention. be able to. As a method for forming the light emitting layer, there is a method for forming a thin film by a known method such as a thin film deposition method, a spin coating method, a casting method, or an LB method.

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

The film thickness of the light emitting layer thus formed is not particularly limited and may be appropriately selected depending on the situation, but is usually in the range of 5 nm to 5 μm.

Next, other layers such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer that are combined with a light emitting layer to form an organic electroluminescent device will be described.

The hole injection layer and the hole transport layer have a function of transmitting 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. As a result, many holes are injected into the light emitting layer at a lower electric field.

Further, the electrons injected from the cathode and transported from the electron injection layer and / or the electron transport layer to the light emitting layer are holes due to the electron barrier existing at the interface between the light emitting layer and the hole injection layer or the hole transport layer. The element is accumulated at the interface in the light emitting layer without leaking to the injection layer or the hole transport layer, and is an element having excellent light emitting performance such as improved light emitting efficiency.

The hole injection material and the hole transport material have any of hole injection or transport and electron barrier properties, and may be either an organic substance or an inorganic substance. Examples of the hole injecting material and the hole transporting material include triazole derivative, oxadiazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative and pyrazolone derivative, phenylenediamine derivative, arylamine derivative, amino-substituted calcon derivative and oxazole. Examples thereof include derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilben derivatives, silazane derivatives, aniline-based copolymers, and conductive polymer oligomers, especially thiophene oligomers. As the hole injecting material and the hole transporting material, the above-mentioned ones can be used, but porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds, particularly aromatic tertiary amine compounds may be used. preferable.

Typical examples of the above aromatic tertiary amine compound and styrylamine compound are 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-) Trillaminophenyl) -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) Audriphenyl, N, N, N-tri (p-tolyl) amine, 4- (di-p-tolylamino) -4'-[4- (di-p-tolylamino) styryl] Stilben, 4-N, N- Diphenylamino- (2-diphenylvinyl) benzene, 3-methoxy-4'-N, N-diphenylaminostillbenzene, N-phenylcarbazole, 4,4'-bis [N- (1-naphthyl) -N-phenyl Examples thereof include amino] biphenyl (NPD), 4,4', 4''-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA).

Inorganic compounds such as p-type-Si and p-type-SiC can also be used as hole injection materials and hole transport materials. 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 vapor deposition method, a spin coating method, a casting method, or an LB method. Can be formed. The film thickness of the hole injection layer and the hole transport layer is not particularly limited, but is usually about 5 nm to 5 μm. The hole injection layer and the hole transport layer may have a one-layer structure composed of one or more of the above materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions.

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

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

Further, in the present invention, the light emitting material is not limited to the light emitting layer, and one kind may be contained in the hole transport layer or the electron transport layer adjacent to the light emitting layer, whereby the organic electroluminescent element may be further contained. The luminous efficiency of the

The substrate preferably used for the organic electroluminescent device of the present invention is not particularly limited in the types such as glass and plastic, and is not particularly limited as long as it is transparent. Examples of the substrate preferably used for the organic electroluminescent element of the present invention include glass, quartz, and a light-transmitting plastic film.

Examples of the light-transmitting plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, and polycarbonate (PC). , A film composed of cellulose triacetate (TAC), cellulose acetate propionate (CAP) and the like.

A suitable example for manufacturing the organic electroluminescent device of the present invention will be described. As an example, a method for manufacturing an organic electroluminescent device including 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 substance, for example, an anode substance, is formed on a suitable substrate by a method such as thin film deposition or sputtering so as to have a film thickness in the range of 1 μm or less, preferably 10 to 200 nm. Make an anode. Next, a thin film composed of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer / electron injection layer, which are element materials, is formed on this.

A buffer layer (electrode interface layer) may be present 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.

Further, in addition to the above basic constituent layer, a layer having other functions may be laminated, if necessary, and a functional layer such as a hole block layer or an electron block layer may be provided.

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

The anode may form a thin film of these electrode materials by a method such as thin film deposition or sputtering to form a pattern having a desired shape by a photolithography method, or a pattern may be formed through a mask having a desired shape during vapor deposition or sputtering. May be formed.

On the other hand, as the cathode, a metal having a small work function (preferably 4 eV or less) (referred to as an electron-injectable metal), an alloy, an electrically conductive compound, or a mixture thereof as an electrode material is 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 ) Examples include mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the viewpoint of electron injectability and durability against oxidation, a mixture of an electron injectable metal and a second metal which is a stable metal having a larger work function value than this, for example, magnesium / silver mixture, magnesium. / Aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, lithium / aluminum mixture and the like are suitable. The cathode can be produced by forming a thin film of these electrode materials by a method such as thin film 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 thin film deposition or sputtering so as to have a film thickness in the range of 1 μm or less, preferably 10 to 200 nm. After forming an anode, each layer thin film composed of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer / electron injection layer is formed on the anode as described above, and then for a cathode. A thin film made of a material is formed to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, by a method such as vapor deposition or sputtering, and a cathode is provided to obtain a desired organic electric field light emitting element.

The organic electroluminescent element of the present invention may be used as a kind of lamp such as for lighting or an exposure light source, a projection device of a type for projecting an image, or a display of a type for directly visually recognizing a still image or a moving image. It may be used as a device (display). When used as a display device for video reproduction, the drive method may be either a simple matrix (passive matrix) method or an active matrix method. Further, a full-color display device can be manufactured by using two or more kinds of organic electroluminescent devices of the present invention having different emission colors.

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

1. 1. Glass substrate with ITO transparent electrode 2. Hole injection layer 3. Charge generation layer 4. Hole transport layer 5. Light emitting layer 6. Electron transport layer 7. Cathode layer

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not to be construed as being limited to these Examples.

^{1 1} H-NMR measurement was performed using Gemini200 (manufactured by Varian).

The emission characteristics of the organic electroluminescent element were evaluated using a luminance meter of LUMINANCEMEMETER (BM-9) (manufactured by TOPCON) by applying a direct current to the manufactured element at room temperature.

Synthesis Example-1

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) under a nitrogen stream. ), And tetrakis (triphenylphosphine) palladium (3.28 g, 2.84 mmol) was suspended in 1,2-dimethoxyethane (600 mL), and the obtained suspension was a 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), a white solid of 2- (5-chloro-biphenyl-3-yl) -4,6-diphenyl-1,3,5-triazine (yield 53.3 g, yield 89%) Got

Synthesis Example-2

2- (5-Chloro-biphenyl-3-yl) -4,6-diphenyl-1,3,5-triazine (3.00 g, 7.1 mmol) obtained in Synthesis Example-1 under a nitrogen stream, bi. Spinnacholate 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 precipitate component was removed by filtration. The filtrate was concentrated under reduced pressure and dried to dryness to obtain a crude product. Methanol was added, and the mixture was stirred and suspended while heating at 65 ° C., and the individual was collected by filtration by hot filtration. By drying the obtained solid under reduced pressure, 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 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 = 8.2Hz, 1H), 9.01 (brs, brs, 1H), 9.24 (brs, 1H).

Synthesis example-3

2- (3-bromo-5-chlorophenyl) -4,6-diphenyl-1,3 under a nitrogen stream
, 5-Triazine (40.0 g, 0.0946 mol), bispinacolat diboron (28.8 g, 11.4 mmol)), and tetrakis (triphenylphosphine) palladium (3.28 g, 2.84 mmol) in tetrahydrofuran (. It was suspended in 600 mL) and stirred at 65 ° C. for 10 hours. After allowing to cool, the precipitate component was removed by filtration. The filtrate was concentrated under reduced pressure and dried to dryness to obtain a crude product. Methanol was added, and the mixture was stirred and suspended while heating at 65 ° C., and the individual was collected by filtration by hot filtration. By drying the obtained solid under reduced pressure, 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) ) Pphenol (0.443 g, 0.383 mmol) and 2 M tripotassium phosphate aqueous 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 with toluene, and the desired product, 4,6-diphenyl-2- [3-chloro-5-{(2-phenylbenzoimidazolyl-1-yl) -biphenyl-3. -Il}]-1,3,5-triazine gray powder (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 tripotassium phosphate aqueous solution (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 with toluene, and the desired product, 4,6-diphenyl-2- [3- (1-phenylbenzoimidazolyl-2-yl) -1,1': 3', A gray powder of 1''-terphenyl-5'-yl] -1,3,5-triazine (A-1) (yield 1.09 g, yield 72%, LC purity 99.59%) was obtained. The Tg of the obtained compound was 125 ° C.

^{1 1} H-NMR (CDCl ₃ ) δ (ppm): 7.39-7.43 (m, 3H), 7.48 (s, 1H), 7.53 (t, J = 7.8Hz, 5H), 7.58-7.62 (m, 8H), 7.67 (s, 1H), 7.74 (d, J = 8.9Hz, 3H), 7.81 (t, J = 7.6Hz, 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 2 M 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 with toluene, and the desired product, 4,6-diphenyl-2- [4- (1-phenylbenzoimidazolyl-2-yl) -1,1': 3', A gray powder of 1''-terphenyl-5'-yl] -1,3,5-triazine (A-30) (yield 1.10 g, yield 73%, LC purity 99.57%) was obtained. The Tg of the obtained compound was 113 ° C.

^{1 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 = 6.6Hz, 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-phenylbenzoimidazole (1.13 g, 3.27 mmol), 4M An aqueous solution 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 obtained 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 with toluene, and the desired product, 4,6-diphenyl-2- [4- (2-phenylbenzoimidazolyl-1-yl) -1,1': 3', A white powder of 1''-terphenyl-5'-yl] -1,3,5-triazine (A-59) (yield 1.17 g, yield 61%, LC purity 99.00%) was obtained. The Tg of the obtained compound was 127 ° C.

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

Synthesis Example-4

4,6-Diphenyl-2- [3-chloro-5-{(2-phenylbenzoimidazolyl-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-quinoline boronic acid (0.92 g, 5.29 mmol), palladium acetate (29.7 mg, 0.132 mmol), 2-dicyclohexiphosphino-2 ', 4', 6'-triisopropylbiphenyl (12.6 mg, 0.027 mmol) and 2M tripotassium phosphate aqueous solution (6.62 mL, 13.2 mmol) were suspended in tetrahydrofuran (45 mL) at 65 ° C. The mixture was stirred 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 with toluene, and the desired product was 4,6-diphenyl-2- [4'-(2-phenylbenzoimidazolyl-1-yl) -5- (3-quinolyl). -Biphenyl-3-yl] -1,3,5-triazine (A-86) gray powder (yield 2.36 g, yield 76%, LC purity 99.99%) was obtained. The Tg of the obtained compound was 136 ° C.

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

Synthesis Example-5

4,6-Diphenyl-2- [3-chloro-5-{(2-phenylbenzoimidazolyl-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-dicyclohexiphosphino-2', 4', 6'-triisopropylbiphenyl (84.1 mg, 0.176 mmol), and 2M. An aqueous solution of tripotassium phosphate (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 with toluene, and the desired product, 4,6-diphenyl-2- [4'-(2-phenylbenzoimidazolyl-1-yl) -5- (6-phenyl-). 3-Pyridyl) -biphenyl-3-yl] -1,3,5-triazine (A-100) gray powder (yield 1.02 g, yield 31.7%, LC purity 99.91%) was obtained. .. The Tg of the obtained compound was 139 ° C.

^{1 1} H-NMR (CDCl ₃ ) δ (ppm): 7.36-7.70 (m, 19H), 7.95 (t, J = 7.2Hz, 4H), 8.11-8.21 (m) , 4H), 8.83 (d, J = 6.9Hz, 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 in which a 2 mm wide indium tin oxide (ITO) film (thickness 110 nm) was patterned in a stripe shape was used. This substrate was washed with isopropyl alcohol and then surface-treated by ozone ultraviolet washing. A substrate after cleaning and vacuum deposition of each layer in the vacuum deposition method to produce a light-emitting area 4 mm ² The organic electroluminescent device as shown in the sectional view of FIG. 1. Each organic material was formed into a film by a resistance heating method.

First, the glass substrate was introduced into the vacuum vapor deposition tank, and the pressure was reduced to ^{1.0 × 10 -4 Pa.}

After that, the hole injection layer 2, the charge generation layer 3, the hole transport layer 4, the light emitting layer 5, the electron transport layer 6, and the cathode layer are formed as organic compound layers on the glass substrate with the ITO transparent electrode shown in FIG. 7 were laminated in this order, and all of them were formed by vacuum vapor deposition.

As the hole injection layer 2, sublimated and purified HIL was formed into a 65 nm film at a rate of 0.15 nm / sec.

As the charge generation layer 3, a sublimated and purified HAT was formed into a 5 nm film at a rate of 0.05 nm / sec.

As the hole transport layer 4, HTL was formed into a 10 nm film at a rate of 0.15 nm / sec.

As the light emitting layer 5, EML-1 and EML-2 were formed into a film at a ratio of 95: 5 (weight ratio) at 25 nm (film formation rate 0.18 nm / sec).

The electron transport layer 6 includes 4,6-diphenyl-2- [3- (1-phenylbenzoimidazolyl-2-yl) -1,1': 3', 1', which was synthesized in Synthesis Example-1 of the present invention. '-Terphenyl-5'-yl] -1,3,5-triazine (Compound A-1) and Liq were formed at a ratio of 50:50 (weight ratio) at 30 nm (deposition rate 0.15 nm / sec). ).

Finally, a metal mask was arranged so as to be orthogonal to the ITO stripe, and the cathode layer 7 was formed into a film. The cathode layer 7 is made of silver / magnesium (weight ratio 1/10) and silver in this order at 80 nm (deposition rate 0.5 nm / sec) and 20 nm (deposition rate 0.2 nm / sec), respectively. It has a two-layer structure.

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

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

Element Example-2
In the electron transport layer 6 of the device Example-1, instead of using the compound A-1, 4,6-diphenyl-2- [4- (1-phenylbenzoimidazolyl-2-yl) synthesized in the synthesis Example-2). -1,1': 3', 1''-terphenyl-5'-yl] -1,3,5-triazine (Compound A-30) is used in the same manner as in Device Example-1. An organic electroluminescent element was created.

Element Example-3
In the electron transport layer 6 of the device Example-1, instead of using the compound A-1, 4,6-diphenyl-2- [4- (2-phenylbenzoimidazolyl-1-yl) synthesized in the synthesis Example-3). -1,1': 3', 1''-terphenyl-5'-yl] -1,3,5-triazine (Compound A-59) is used in the same manner as in Device Example-1. An organic electroluminescent element was created.

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

A direct current was applied to the produced organic electroluminescent element, and the 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 the current efficiency (cd / A) when a current density of 10 mA / cm ^{2 was passed were measured, and the element life during continuous lighting was measured.} The life of the element is determined by measuring the luminance decay time during continuous lighting when the ^{initial luminance is driven at 1000 cd / m 2 , and measuring the time required for the luminance (cd / m 2} ) to decrease by 25%. In the element reference example-1, it is expressed as a relative value when the time required for the ^{luminance (cd / m 2) to be reduced by 25% is set 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 luminous efficiency and device life as compared with the reference example.

The present invention provides a novel triazine compound that enables high efficiency and long life of an organic electroluminescent element by using it as an electron transport layer, and further provides low voltage using the compound. It provides an organic electroluminescent element.

Claims (13)

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

(During the ceremony,
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 ring nitrogen-containing aromatic group consisting of only a 6-membered ring and having 3 to 13 carbon atoms (the group is fluorine). It may be substituted with 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 is a single bond or an arylene group having 4 to 14 carbon atoms (the 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). show.
R represents a kind of group selected from the following general formulas (2) to (4). )

(In the formula, Ar ³ and Ar ⁴ are independently monocyclic, linked or condensed aromatic hydrocarbon groups having 6 to 18 carbon atoms (the group is a fluorine atom and 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 ring or a shrunken ring having 3 to 13 carbon atoms composed of only a 6-membered ring. Even if the ring-containing nitrogen-containing aromatic group is 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).) 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 a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a 1-anthryl group, a 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 tenyl 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.} A material for an organic electroluminescent device, which comprises the triazine compound according to claim 1. An electron transport material for an organic electroluminescent device, which comprises the triazine compound according to claim 1.

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