JP2015034148A - Triazine compound having anthryl group and organic electroluminescent element containing the same - Google Patents

Abstract

An object of the present invention is to provide a specific triazine compound that remarkably improves the device life, luminous efficiency (current efficiency, etc.), or driving voltage of an organic electroluminescent device as compared with conventionally known triazine compounds. SOLUTION: A triazine compound represented by the general formula (1) and an organic electroluminescence device having this as a constituent are produced. (In general formula (1), X represents a phenylene group or a single bond. Y represents a nitrogen atom or CH.) [Selection Figure]

Description

  The present invention relates to a triazine compound useful as a constituent component of an organic electroluminescence device, and more particularly to a triazine compound characterized by having an anthryl group in the molecule and an organic electroluminescence device containing the triazine compound.

  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. Although recent organic electroluminescence devices are gradually improved in the above-mentioned drawbacks, excellent materials are demanded for the purpose of further improving the luminous efficiency characteristics, driving voltage characteristics, and long life characteristics. Among them, improvement in device life, light emission efficiency (current efficiency, etc.) or drive voltage is an urgent need for widespread use in a wide range of fields, and material development therefor is required.

  As an electron transport material excellent in long life property for an organic electroluminescent element, the triazine compound disclosed in Patent Document 1 can be mentioned. However, further improvements have been demanded in terms of the lifetime of the organic electroluminescent device, the luminous efficiency (current efficiency, etc.), or the driving voltage.

JP 2011-063584 A

  An object of the present invention is to provide a specific triazine compound that remarkably improves the device life, light emission efficiency (current efficiency, etc.) or driving voltage of an organic electroluminescent device as compared with a conventionally known triazine compound. . Another object of the present invention is to provide an organic electroluminescent device excellent in long life, luminous efficiency (current efficiency, etc.) or driving voltage using the specific triazine compound.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have developed an organic compound using a triazine compound represented by the following general formula (1) having an anthryl group as an electron transport material. The electroluminescent device has been found to exhibit significantly longer life characteristics, luminous efficiency (current efficiency, etc.), or driving voltage 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.

(In general formula (1), X represents a phenylene group or a single bond. Y represents a nitrogen atom or CH.)

  The triazine compound of the present invention can provide an organic electroluminescent device that is significantly superior in lifetime, luminous efficiency (current efficiency, etc.) or driving voltage as compared with conventionally known triazine compounds.

  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), X represents a single bond or a phenylene group. The phenylene group is not particularly limited, and examples thereof include an o-phenylene group, an m-phenylene group, and a p-phenylene group. X is preferably a single bond or a p-phenylene group from the viewpoint of excellent lifetime of the organic electroluminescence device.

  Y represents a nitrogen atom or CH.

  The triazine compound represented by the general formula (1) is preferably a triazine compound represented by the following general formula (2) from the viewpoint of excellent lifetime of the organic electroluminescence device.

(In general formula (2), X represents a phenylene group or a single bond. Y represents a nitrogen atom or CH.)
Specific examples of the triazine compound represented by the general formula (1) include the following (A-1) to (A-16), but the present invention is not limited thereto.

  Among these compounds, a compound represented by the following formula (A-1), (A-4), or (A-6) is preferable in that the lifetime of the organic electroluminescent element is excellent.

  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, an LB method.

  The light emitting layer can be obtained by dissolving the 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 or the like 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 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 electroluminescence device, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (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 a photolithography method, 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 using an electrode substance of a metal having a small work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound and a mixture thereof 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 (3.00 g, 7.10 mmol), 3-pyridylboronic acid (1.13 g, 9 .19 mmol), 1,2-dimethoxyethane (50 mL) was added to a 100 mL two-necked flask, and 10% NaOH aqueous solution (6.15 g, 21.3 mmol) was added dropwise over 3 minutes, followed by tetrakistriphenylphosphine palladium. (82 mg, 0.071 mmol) was added and stirred at 70 ° C. for 8 hours. After allowing to cool to room temperature, water (20 mL) was added to the reaction mixture, and the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water, methanol, and hexane to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and the desired product 2- [5-chloro-3- (3-pyridyl) phenyl] -4,6-diphenyl-1,3,5-triazine Of an off-white powder (yield 2.41 g, yield 80.6%, LC purity 99.55%).
Synthesis Example-1

Under an argon stream, 2- [5-chloro-3- (3-pyridyl) phenyl] -4,6-diphenyl-1,3,5-triazine (1.00 g, 2.38 mmol) obtained in Synthesis Example-1. ), 9-anthraceneboronic acid (0.63 g, 2.85 mmol), palladium acetate (16.0 mg, 0.071 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl (67. 9 mg, 0.14 mmol) was suspended in tetrahydrofuran (20 mL) and heated to 70 ° C. 2M aqueous K ₂ CO ₃ solution (3.56 mL, 7.13 mmol) was added and stirred for 2 hours. Furthermore, 9-anthraceneboronic acid (0.42 g, 1.90 mmol) was added, and the mixture was stirred at 70 ° C. for 15 hours. After cooling to room temperature, water (30 mL) and methanol (30 mL) were added to the reaction mixture, and the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water, methanol, and hexane to obtain a white powder. The obtained white powder was purified by recrystallization from toluene, and the desired product 2- [5- (9-anthryl) -3- (3-pyridyl) phenyl] -4,6-diphenyl-1,3 was obtained. , 5-triazine (compound A-4) was obtained as a white powder (yield 0.87 g, yield 65%).

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.40 (ddd, J = 8.7 Hz, 6.6 Hz, 1.2 Hz, 2H), 7.48-7.61 (m, 8H), 7 .65-7.70 (m, 1H), 7.72 (dd, J = 8.8 Hz, 0.9 Hz, 2H), 7.91 (t, J = 1.8 Hz, 1H), 8.11 ( d, J = 8.5 Hz, 2H), 8.37 (brd, J = 8.2 Hz, 1H), 8.61 (s, 1H), 8.70-8.73 (m, 1H), 8. 73 (dd, J = 8.8 Hz, 1.6 Hz, 4H), 8.95 (t, J = 1.6 Hz, 1H), 9.16 (brd, J = 2.4 Hz, 1H), 9.19 (T, J = 1.7 Hz, 1H).
Synthesis Example-2

Under an argon stream, 2- (3-bromo-5-chlorophenyl) -4,6-diphenyl-1,3,5-triazine (14.6 g, 34.5 mmol), 9-anthraceneboronic acid (10.0 g, 45 0.0 mmol), tetrakis (triphenylphosphine) palladium (798 mg, 0.69 mmol), suspended in a toluene / ethanol (4: 1) mixture (216 mL), and then 2.0 M aqueous potassium carbonate solution (34 .5 mL, 104 mmol) was added dropwise. The reaction mixture was then stirred at 80 ° C. for 18 hours. After allowing to cool, water was added, the precipitated solid was filtered off, and the solid was washed with water, methanol and hexane. Further, by purification by recrystallization (toluene), the desired 2- [5- (9-anthryl) -3-chlorophenyl] -4,6-diphenyl-1,3,5-triazine yellowish white solid (yield 14. 4 g, yield 80%).
Synthesis Example-2

  2- [5- (9-anthryl) -3-chlorophenyl] -4,6-diphenyl-1,3,5-triazine (10.0 g, 19 mmol), phenyl obtained in Synthesis Example-2 under an argon stream Boronic acid (3.05 g, 25.0 mmol), palladium acetate (130 mg, 0.58 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl (550 mg, 1.2 mmol), potassium carbonate (6.91 g, 50 mmol) was suspended in a mixed solvent of toluene (190 mL) and ethanol (48 mL), and water (48 mL) was added dropwise. The reaction mixture was then stirred at 70 ° C. for 2 hours. After allowing to cool, methanol and water were added, the precipitated solid was filtered off, and the solid was washed with water, methanol and hexane. Further, the desired 2- [5- (9-anthryl) -biphenyl-3-yl] -4,6-diphenyl-1,3,5-triazine (Compound A-1) is purified by recrystallization (toluene). Of a white solid (yield 9.72 g, yield 90%) was obtained.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.42-7.46 (m, 3H), 7.50-7.60 (m, 9H), 7.3 (dd, J = 1.1 , 6.5 Hz, 1H), 7.65 (dd, J = 1.1, 6.5 Hz, 1H), 7.80-7.85 (m, 4H), 7.91 (t, J = 1. 6 Hz, 1H), 8.65 (d, J = 9.0 Hz, 2H), 8.75 (d, J = 7.0 Hz, 4H), 8.80 (t, J = 1.6 Hz, 1H), 9.22 (t, J = 1.6 Hz, 1H).
Synthesis example-3

Under a nitrogen stream, 2- (3-bromo-5-chlorophenyl) -4,6-diphenyl-1,3,5-triazine (10.0 g, 23.7 mmol), 4- (3-pyridyl) phenylboronic acid ( 4.94 g, 24.8 mmol) and tetrahydrofuran (150 mL) were added to a 500 mL four-necked flask, and 10% NaOH aqueous solution (30.2 g, 71.1 mmol) was added dropwise thereto, followed by tetrakistriphenylphosphine palladium (0.548 g). , 0.474 mmol) and stirred at 75 ° C. for 15 hours. After allowing to cool to room temperature, water (150 mL) was added to the reaction mixture, and the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water, methanol, and hexane to obtain a gray powder. Thereafter, the obtained gray powder was purified by recrystallization from toluene, and the desired product 2- [5-chloro-4 ′-(3-pyridyl) biphenyl-3-yl] -4,6-diphenyl- An off-white powder of 1,3,5-triazine (yield 11.8 g, yield 99.9%, LC purity 98.61%) was obtained.
Synthesis Example-3

2- [5-Chloro-4 ′-(3-pyridyl) biphenyl-3-yl] -4,6-diphenyl-1,3,5-triazine (6) obtained in Synthesis Example-1 under a nitrogen stream 0.000 g, 12.1 mmol), 9-anthraceneboronic acid (3.21 g, 14.5 mmol), palladium acetate (54.3 mg, 0.242 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′- Triisopropylbiphenyl (231 mg, 0.484 mmol) and tetrahydrofuran (90 mL) were added to a 200 mL four-necked flask and heated to 60 ° C. A 20% K ₂ CO ₃ aqueous solution (21.8 g, 31.5 mmol) was added dropwise thereto over 5 minutes, and the mixture was stirred at 75 ° C. for 21 hours. After allowing to cool to room temperature, water (60 mL) was added to the reaction mixture, and the precipitate was collected by filtration. The precipitate collected by filtration was washed successively with pure water, methanol, and hexane to obtain a gray powder. The obtained gray powder was purified by recrystallization from toluene, and the target product 2- [5- (9-anthryl) -4 ′-(2-pyridyl) biphenyl-3-yl] -4,6- An off-white powder (yield 4.70 g, yield 61.0%, LC purity 99.78%) of diphenyl-1,3,5-triazine (compound A-6) was obtained.

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.26-7.29 (m, 1H), 7.37-7.41 (m, 3H), 7.48-7.60 (m, 7H) ), 7.74 (d, J = 8.7 Hz, 2H), 7.81 (d, J = 8.9 Hz, 2H), 7.92-7.97 (m, 4H), 8.11 (d , J = 8.4 Hz, 2H), 8.59 (s, 1H), 8.61 (dd, J = 5.0 Hz, 1.6 Hz, 1H), 8.74 (dd, J = 8.5 Hz, 1.6 Hz, 4H), 8.85 (t, J = 1.6 Hz, 1H), 8.92 (brd, J = 2.1 Hz, 1H), 9.24 (t, J = 1.8 Hz, 1H) ).
The structural formulas and abbreviations of the compounds used for device evaluation are shown below.

Element Reference 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, 2- [5- (9-phenanthryl) -4 ′-(2-pyrimidyl) biphenyl-3-yl] -4,6-diphenyl-1 described in JP2011-063584A is used. , 3,5-triazine (ETL-1) and Liq were deposited at a ratio of 50:50 (weight ratio) to a thickness of 30 nm (deposition rate of 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.

A direct current was applied to the organic electroluminescence device produced as described above, and the light emission characteristics were evaluated using a luminance meter of LUMINANCE METER (BM-9) manufactured by TOPCON. As light emission characteristics, voltage (V) and current efficiency (cd / A) when a current density of 10 mA / cm ² was passed were measured, and element lifetime (h) during continuous lighting was measured. Note that the device lifetime (h) until were prepared device to measure the luminance decay time at the time of continuous lighting when driven at an initial luminance 800 cd / ^{m 2,} the luminance (cd / ^{m 2)} is reduced 30% (560 cd / The time required until m ² was measured. The element lifetime (h) in this element reference example-1 was defined as the reference value (100). The results are shown in the table below.
Element Example-1
In Device Reference Example-1, 2- [5- (9-anthryl) -3- (3-pyridyl) phenyl] -4,6-diphenyl-1, synthesized in Synthesis Example-1 instead of ETL-1 An organic electroluminescent element was prepared and evaluated in the same manner as in Element Reference Example 1 except that 3,5-triazine (Compound A-4) was used. The results are shown in the table below. In addition, about element lifetime, after measuring element lifetime (h), it represented with the relative value which set the element lifetime of element reference example-1 to 100.
Element Example-2
In Device Reference Example 1, 2- [5- (9-anthracenyl) -biphenyl-3-yl] -4,6-diphenyl-1,3,5 synthesized in Synthesis Example-2 instead of ETL-1 -An organic electroluminescent element was prepared and evaluated by the same method as in Element Reference Example 1 except that triazine (Compound A-1) was used. The results are shown in the table below. In addition, about element lifetime, after measuring element lifetime (h), it represented with the relative value which set the element lifetime of element reference example-1 to 100.
Element Example-3
In Device Reference Example 1, 2- [5- (9-anthryl) -4 ′-(2-pyridyl) biphenyl-3-yl] -4,6 synthesized in Synthesis Example-3 instead of ETL-1 -An organic electroluminescent element was prepared and evaluated by the same method as in Element Reference Example 1 except that diphenyl-1,3,5-triazine (Compound A-6) was used. The results are shown in the table below. In addition, about element lifetime, after measuring element lifetime (h), it represented with the relative value which set the element lifetime of element reference example-1 to 100.

  From Table 1, it was found that the organic electroluminescence device using the triazine compound of the present invention was remarkably superior in device lifetime as compared with the reference example. In addition, it was found that the triazine compound of the present invention exhibits characteristics exceeding the driving voltage and current efficiency of the organic electroluminescence device as compared with the reference example.

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

Claims (8)

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

(In general formula (1), X represents a phenylene group or a single bond. Y represents a nitrogen atom or CH.) The triazine compound according to claim 1 represented by the general formula (2).

(In general formula (2), X represents a phenylene group or a single bond. Y represents a nitrogen atom or CH.) The triazine compound according to claim 1 or 2, wherein Y is a nitrogen atom. The triazine compound according to claim 1 or 2, wherein X is a single bond or 3. The triazine compound according to claim 1 or 2, which is represented by the following formula (A-1), (A-4) or (A-6).

An organic electroluminescent device comprising a triazine compound represented by the general formula (1).

(In general formula (1), X represents a phenylene group or a single bond. Y represents a nitrogen atom or CH.) The organic electroluminescent element according to claim 6, wherein the triazine compound represented by the general formula (1) is contained in the electron transport layer. The organic electroluminescent element according to claim 6 or 7, wherein the triazine compound represented by the general formula (1) is used as a co-evaporated film with Liq.

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