JP3207542B2 - Organic electroluminescence device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-emitting device having a light-emitting layer in which a substance that emits light by current injection is formed by utilizing the electroluminescence of the substance, and in particular, the light-emitting layer emits an organic compound. The present invention relates to an organic electroluminescent element (hereinafter, referred to as an organic EL element) configured as a body.

[0002]

2. Description of the Related Art As an organic EL device of this type, as shown in FIG. 1, a phosphor thin film 3, which is made of an organic compound, is laminated between a metal cathode 1 and a transparent anode 2, that is, a light emitting layer and a positive electrode. A two-layer structure in which a hole transport layer 4 is disposed, or an electron transport layer 5 made of an organic compound laminated between a metal cathode 1 and a transparent anode 2 as shown in FIG.
A three-layer structure in which a light emitting layer 3 and a hole transport layer 4 are arranged is known. Here, the hole transporting layer 4 has a function of easily injecting holes from the anode (hole transporting property) and a function of blocking electrons, and the electron transporting layer 5 has a function of easily injecting electrons from the cathode. Electron transportability).

In these organic EL devices, a transparent anode 2
A glass substrate 6 is disposed outside the substrate, and excitons are generated by recombination of electrons injected from the metal cathode 1 and holes injected from the transparent anode 2 into the light emitting layer 3, and the excitons are radiated. Light is emitted in the process of deactivation, and this light is emitted outside through the transparent anode 2 and the glass substrate 6. Further, FIG.
An organic EL device having a two-layer structure shown in FIG. 1 and in which the light emitting layer 3 is formed from an organic host material having an electron transporting property and a fluorescent guest material to emit light stably has been developed.

[0004]

However, in the conventional organic compound organic EL device having the above-described structure, an organic EL device that emits blue light with higher luminance is desired. An object of the present invention is to provide an organic EL device capable of emitting blue light with high luminance.

[0005]

The organic EL device according to the present invention comprises:
An anode, a hole transport layer made of an organic compound, a light emitting layer made of an organic compound, and a cathode are sequentially laminated, and the light emitting layer is a pyrimidopyrimidine derivative represented by Chemical Formula 1.

[0006]

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[0007] In the chemical formula 1, R ₁ , R ₂ , R _{3 and} R ₄ each independently represent a hydrogen atom, a halogen atom or a group represented by the chemical formula 2,

[0008]

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In the chemical formula 2, R _{5 and} R ₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, or an atom which completes a cycloalkyl group or a heterocyclic group when R ₅ and R ₆ are taken together. Or｝ representing a group.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The organic EL device of the present invention is the same as the organic EL device having the structure shown in FIGS. 1 and 2, and has a light emitting layer 3 and a transparent anode 2 between a pair of metal cathodes 1 and a transparent anode 2 as shown in FIG. Hole transport layer 4
Are laminated and formed as a thin film, or as shown in FIG. 2, an electron transport layer 5, a light emitting layer 3, and a hole transport layer 4 are formed between a pair of metal cathodes 1 and a transparent anode 2. The structure may be sufficient. In any case, one of the electrodes 1 and 2 only needs to be transparent. For example, the cathode 1 is made of an alkaline earth metal such as aluminum and magnesium, an alkali metal such as indium, silver and lithium, or a metal having a small work function such as an alloy thereof and having a thickness of about 100 to 5000 mm. obtain. Further, for example, the anode 2 is made of a conductive material having a large work function such as indium tin oxide (hereinafter, referred to as ITO) and has a thickness of about 1000 to 3000 mm, or gold and has a thickness of about 800 to 1500 mm. Can be used. When gold is used as an electrode material, the electrode is in a translucent state.

The light-emitting layer 3 is composed of Pyrimido [5,4]
-d] Pyrimidine). R ₅ and R _{6 in} the above Chemical Formula 2 are each independently a hydrogen atom, an alkyl group, an aryl group, or R ₅
And R ₆ are preferably an atom or a group which completes a cycloalkyl group or a heterocyclic group, so that R _{1 to} R ₄ in the pyrimidopyrimidine derivative of the above formula 1 are each independently added. A hydrogen atom, a halogen atom and a group represented by the above chemical formula 2. For example,
Such a set includes a hydrogen atom, a fluorine atom, a halogen atom such as chlorine and bromine, a diethanolamino group (diethanolamino),
Ethanolamino group (ethanolamino), piperidino group (pip
eridino), p-methoxyanilino group (p-methoxyanlino), m
-Methoxyanilino group, morpholino group
(morpholino), anilino group (anilino), benzylamino group (benzylamino), diphenylamino group (diphenylamin
o), a pyrrolidino group (pyrrolidino), a piperidino group (pipe
ridino), thiazolidino groups and thiomorpholino groups.

As described above, typical heteroatoms contained in the heterocyclic group of the above formula 2 in the pyrimidopyrimidine derivative of the above formula 1 include nitrogen, oxygen, sulfur and the like. In addition, the various alkyl groups, alkylene groups, aryl groups, and arylene groups in the chemical formula 2 may be substituted. Representative such substituents include alkyl, alkoxy, aryl, aryloxy and halogen atoms such as fluorine, chlorine and bromine.

Further, for example, the pyrimidopyrimidine derivative has a structure represented by the following chemical formula 3.

[0014]

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In the chemical formula 3, R _{1 and} R ₂ are different from each other, each of which is a hydrogen atom, a halogen atom,
And may represent a group represented by the formula: embedded image

[0016]

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In formula 4, R _{5 and} R ₆ are each independently a hydrogen atom, an alkyl group, an aryl group, or R ₅ and R ₆ are taken together to complete a cycloalkyl group or a heterocyclic group. It may be｝ representing an atom or a group. Specific examples of pyrimidopyrimidine derivatives include dipyridamole (Dipyridamomol) used in a fluorescent analysis reagent.
le), which can be included in the light emitting layer 3 to form an organic EL device. Dipyridamole (2,6-bis (diethanolamino) -4,8-didiperidino Pyrimid
o [5,4-d] Pyrimidine) is represented by Chemical Formula 5.

[0018]

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This dipyridamole is a pyrimido [5,
4-d] pyrimidine skeleton has a diethanolamino group at the 2,6-position and a piperidino group (didi-amino) at the 4,8-position.
peridino), and has the structure represented by Chemical Formulas 3 and 4 above. Other pyrimidopyrimidine derivatives include, for example, tri (p-methoxyanilino)
Pyrimido [5,4-d] pyrimidine ｛2,4,8-tri (p-met
hoxyanlino) Pyrimido [5,4-d] Pyrimidine｝,

[0020]

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2,4,6,8-Tetramorpholinopyrimido [5,4-d] pyrimidine {2,4,6,8-t represented by Chemical Formula 7
etramorpholino Pyrimido [5,4-d] Pyrimidine｝,

[0022]

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2,4,6,8-Tetraanilinopyrimido [5,4-d] pyrimidine {2,4,6,8-tet represented by Chemical Formula 8
raanilino Pyrimido [5,4-d] Pyrimidine｝,

[0024]

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The 2,4,6,8-tetra (p-
Methoxyanilino) pyrimido [5,4-d] pyrimidine {2,4,6,8-tetra (p-methoxyanlino) Pyrimido [5,4-d] P
yrimidine｝,

[0026]

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The 2,4,6,8-tetrabenzylaminopyrimido [5,4-d] pyrimidine {2,4,
6,8-tetrabenzylamino Pyrimido [5,4-d] Pyrimidin
e｝,

[0028]

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2,4,8-Trimorpholinoaminopyrimido [5,4-d] pyrimidine {2,4,8
−trimorpholino Pyrimido [5,4-d] Pyrimidine｝,

[0030]

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2,4,8-Tripyrrolidinopyrimido [5,4-d] pyrimidine {2,4,8-tri
pyrrolidino Pyrimido [5,4-d] Pyrimidine｝,

[0032]

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The 2,4,8-tetrapiperidinopyrimido [5,4-d] pyrimidine {2,4,6,8-t represented by the chemical formula 13
etrapiperidino Pyrimido [5,4-d] Pyrimidine｝,

[0034]

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The 2,4,8-tetrathiomorpholinopyrimido [5,4-d] pyrimidine {2,4,6,
8-tetrathiomorpholino Pyrimido [5,4-d] Pyrimidin
e｝,

[0036]

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And the like. An organic EL device having a two-layer or three-layer structure can be formed using only the above pyrimidopyrimidine derivative for the light-emitting layer 3. The light emitting layer 3 has
In a layer structure, the pyrimidopyrimidine derivative may be formed as a small amount of a fluorescent guest material by mixing with a large amount of an electron-transporting organic host material.

The host material of the light emitting layer 3 is t-Bu-PBD ｛2- (4'-tert-Butylphenyl) -5-
(biphenyl) -1,3,4-oxadiazole｝ or tris (8-quinolinol) aluminum of the following chemical formula 15

[0039]

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It is preferable to use a quinoline derivative such as Other quinoline derivatives include, for example, bis (8-quinolinol) magnesium, bis (benzo {f} -8-
(Quinolinol) zinc, bis (2-methyl-8-quinolinol) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinollithium, tris (5-chloro-8- Quinolinol) gallium, bis (5-chloro-8-quinolinol) calcium, and poly [zinc (II) -bis (8-hydroxy-5-
Quinolinyl) methane].

As described above, the above pyrimidopyrimidine derivative is used as the guest substance of the light emitting layer. In this case, it is preferable that the atomic ratio of the organic host substance having an electron transporting property is larger than the atomic ratio of the pyrimidopyrimidine derivative as the fluorescent guest substance. Here, the pyrimidopyrimidine derivative of the guest substance is, for example, t-Bu-PB of the host substance.
It is preferable that D is contained in the light emitting layer at a concentration or an atomic ratio of 1% or less. This is because light emission with high luminance can be obtained with a low applied voltage.

Next, in the hole transport layer 4, for example, a tetraphenyldiamine derivative (hereinafter referred to as TPD), for example, N, N'-diphenyl-
N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine is preferably used, and CTM (Carrier Transporting) represented by the following chemical formulas 17 to 27:
Materials) can be used alone or as a mixture.

[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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In the above embodiment, the light emitting layer 3 and the organic hole transporting layer 4 are arranged between the cathode 1 and the anode 2. However, as shown in FIG. The same effect can be obtained also in a three-layer organic EL device in which the organic electron transport layer 5 made of a perylene tetracarboxyl derivative represented by the following chemical formula 33 is provided. Further, the electron transport layer 5
Is the above-mentioned t-Bu- represented by the following chemical formula 28:
PBD is preferably used, and the following chemical formulas 29 to 3
The compound represented by 9 may also be used.

[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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Specifically, an EL device having a light emitting layer containing dipyridamole was prepared. (Example 1) Including dipyridamole as a guest substance
EL element having light emitting layer First, a plurality of ITO thin films are formed on a glass substrate in a belt shape (2 mm).
The glass substrate with ITO formed in (width) was prepared, and this was ultrasonically cleaned in a mixture of isopropyl alcohol and distilled water (1: 1, volume ratio) for 5 minutes. The washed substrate is then rinsed well in ethyl alcohol, dried with toluene vapor and further placed in a 75 ° C. oven.
Hold for 0 minutes and dry.

Next, the dried I
The TPD of the above formula 16 was placed on a TO glass substrate in a tantalum boat, and TPD was vacuum-deposited to a thickness of 500 ° to form a hole transport layer. Next, the t-Bu-PBD of the above formula 28 and dipyridamole of the above formula 5 were deposited on the hole transporting layer composed of TPD by a two-source evaporation method.
The light emitting layer was formed by vacuum evaporation using a rce evaporation technique). That is, t-Bu-PBD and dipyridamole were co-evaporated from two boats while adjusting the evaporation rate so as to obtain a desired composition by two monitors. Here, a light emitting layer made of a mixture thereof was formed to a thickness of 500 ° at such a rate that t-Bu-PBD had a deposition rate of 500 ° / sec and dipyridamole had a deposition rate of 10 ° / sec.

Next, 0.2 cm × 3 cm was placed on the mixed light emitting layer.
Is placed, and Mg and Al are vacuum-deposited by a two-source vapor deposition method so as to have a composition atomic ratio of 10: 1 and a film thickness of 2500 ° to form electrodes, thereby forming a two-layer E shown in FIG.
An L element was prepared. In addition, current and luminance response characteristics (IVL characteristics) with respect to voltage for the obtained EL element
Was measured. A positive voltage was applied to the ITO electrode, and the Mg-Al electrode was connected to the ground via an ammeter. Light emitted from the EL element cell was detected by a photometer. The cell starts to emit light at about 6V, and at 219 cd / m ² and 0.0139 lm / w at 15V.
And the device was destroyed at about 16 V (FIG. 3).

Next, the emission spectrum of the obtained EL device was measured. The spectral shape of the electroluminescence (EL) emission light of the EL device was observed with a photometer (FIG. 4a). The spectral shape of the photoluminescence (PL) emission light of dipyridamole in a dioxane solution was also observed with a photometer (FIG. 4b). E of the EL element obtained here
Since the L emission spectrum shape and the peak wavelength matched those of the PL emission spectrum of dipyridamole in the dioxane solution, it was confirmed that dipyridamole emitted light in this device. (Examples 2 to 9) Guess various pyrimidopyrimidine derivatives
An EL device having a light emitting layer containing the same as the ITO material, except that the pyrimidopyrimidine derivatives represented by the above Chemical Formulas 6 to 13 were used as guest materials as Examples 2 to 9, respectively. TPD
An EL device comprising a hole transport layer, a t-Bu-PBD, a hole transport layer of each guest substance, and an Mg-Al electrode was prepared. The luminous characteristics of luminance L, luminous efficiency η, and current density I as shown in Table 1 are shown.

Table 1 EL element L (cd / m ² ) η (lm / w) I (A / cm ² ) Example 2 23 0.0103 0.070 Example 3 130 0.0548 0.039 Example 4 41 0.0158 0.047 Example 5 31 0.0643 0.0058 Example 6 13 0.00263 0.1033 Example 7 110 0.0193 0.0813 Example 8 149 0.0124 0.2782 Example 9 54 0.0392 0.0221 The emission spectrum distributions of the organic EL devices of Examples 2 to 9 are shown in FIGS. FIGS. 5A to 12A and FIG.
The figure shows the spectrum distribution of the EL emission light of the EL element itself and the spectrum distribution of the pyrimidopyrimidine derivative PL emission light represented by Chemical Formulas 6 to 13 in a dioxane solution.

As shown in FIGS. 5A and 5B, the EL spectra of Examples 2 to 9 were identical or similar to the PL spectra of the various pyrimidopyrimidine derivatives used for the guest substances, respectively. It was confirmed that light emission of various pyrimidopyrimidine derivatives was generated in the light emitting layer of each device. Example 10 Having a light emitting layer containing only dipyridamole
EL element to be formed on a glass substrate with ITO as described in Example 1.
Dipyridamole was deposited in a thickness of 500 ° on top of PD deposited in a thickness of 500 °. On this, Mg-Al was deposited in a thickness of 2000 ° in the same manner as in Example 1.

The I-V-L characteristics of the obtained EL device were measured in the same manner as in Example 1. When the emission characteristics were measured, pale emission was observed at about 15 V. further,
In order to prepare another embodiment, 2,6-dimorpholino-4,8-dipiperidinopyrimido represented by the following formulas 40 to 44 contained in the pyrimidopyrimidine derivative of the above formula 1
[5,4-d] pyrimidine (2,6- (Dimorphorino-4,8-dipiperid
ino Pyrimido [5,4-d] Pyrimidine), 2,6-bis (hydroxyethylmethylamino) -4,8-dipiperidinopyrimido
[5,4-d] pyrimidine (2,6-bis (hydroxyethyl-methyl-ami
no) -4,8-dipiperidino Pyrimido [5,4-d] Pyrimidine),
2,6-bis (hydroxyethylmethylamino) -4,8-dithiomorpholinopyrimido [5,4-d] pyrimidine (2,6-bis (hyd
(roxyethyl-methyl-amino) -4,8-dithiomorphorino Pyrim
ido [5,4-d] Pyrimidine), 2,6-bis (hydroxyethylmethylamino) -4,8-dimorpholinopyrimido [5,4-d] pyrimidine (2,6-bis (hydroxyethyl-methyl- amino) -4,8-dim
orphorino Pyrimido [5,4-d] Pyrimidine), 2,6-bis (hydroxyethylmethylamino) -4,8-dipyrrolidinylpyrimido [5,4-d] pyrimidine (2,6-bis (hydroxyethy
l-methyl-amino) -4,8-dipyrrolidinyl Pyrimido [5,4-d]
Pyrimidine) was prepared.

[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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(Example 11) Pyrimido represented by the chemical formula 40
Has a light-emitting layer containing a pyrimidine derivative as a guest substance
EL element under the same conditions as in Example 1 with a film thickness of 10
It has an ITO anode of 00Å, a TPD hole transport layer of 500Å thickness, and a MgAl cathode of 900Å thickness.
A co-deposited thin film comprising Bu-PBD and a pyrimidopyrimidine derivative of Formula 40, wherein the deposition rate of the t-Bu-PBD is 600Å / sec, the deposition rate of the pyrimidopyrimidine derivative is 1.5Å / sec, 3Å / sec; 3.75 ° / sec;
Six EL devices having a two-layer structure having a light-emitting layer 9 having a film thickness of 600 ° changed at 5 ° / sec, 35 ° / sec and 52 ° / sec were prepared.

I-V-L characteristics of the obtained EL device
Was measured. Table 2 shows the resulting luminance L, luminous efficiency η,
5 shows light emission characteristics at a pressure V.Table 2 Pyrimidopyrimidine derivatives Concentration (Å / sec) η (lm / w) * L (cd / m ² ) ** V (V) ** 1.5 0.26 17.05 13.18 3 0.21 19.10 11.62 3.75 0.18 16.70 14.39 4.5 0.22 26.73 13.44 35 0.21 38.90 7.1652 0.26 62.38 9.35 * 10^-3A / cm^TwoHour ** 10^-3A / 4mm^TwoTime As is clear from Table 2, the change in guest substance concentration
And the emission spectrum changes significantly,
Almost the same, but the brightness increased greatly. That is injected
Number of electrons and holes is not affected by guest substance concentration
However, the rate at which electrons and holes recombine and emit light in a molecule is
Increases with the concentration of the substance
It can be seen that the brightness at the stream value is increased.
You.

Next, the emission spectrum of the obtained EL device was measured. The spectral shape of the EL emission light of the EL element was observed with a photometer. When the guest substance concentration is as small as 1.5Å / sec, a peak of 470 nm appears beside the peak of 400 nm, and as the concentration of guest substance increases, the peak of 400 nm decreases and the peak of 470 nm increases, which is dominant. Became. The hue of light emission changed from blue near purple to blue near green. (Examples 12 to 15) Various pyrimidopyrimidine derivatives
An EL device having a light emitting layer containing a guest material As in Examples 12 to 15, an ITO glass substrate was used in the same manner as in Example 11, except that the pyrimidopyrimidine derivatives represented by the above Chemical Formulas 41 to 44 were used as guest materials. An EL device including a hole transport layer of TPD, t-Bu-PBD, a hole transport layer of each guest substance, and a MgAl electrode was prepared. Table 3 shows the emission characteristics of the guest substance concentration, the luminous efficiency η, and the current-luminance relationship IL, respectively.

[0083]Table 3 Guest substance EL element concentration (Å / sec) η (lm / w) IL Example 11 52 0.25 logL = 1.05 * logI + 173x10^-6 Example 12 40 0.13 logL = 0.89 * logI + 178x10^-6 Example 13 35 0.11 logL = 0.91 * logI + 272x10^-6 Example 14 15 0.09 logL = 0.89 * logI + 425x10^-6 Example 15 7 0.04 logL = 1.01 · logI + 1091x10 ^-6  Furthermore, each pyrimidopyrimidi used in Examples 11 to 15
10 derivatives^-FourM dioxane solution, PL emission light
Was observed with a photometer. So
Table 4 shows the peak wavelengths and their intensities.

Table 4 EL device Peak wavelength (nm) Intensity (eV) Example 11 470 4055 Example 12 473 3586 Example 13 482 3559 Example 14 479 3644 Example 15 461 4079

[0085]

As described above, since the organic EL device according to the present invention has the light-emitting layer containing the pyrimidopyrimidine derivative of the above formula 1, it can emit high-luminance blue light at a low applied voltage. Further, according to the present invention, the luminous efficiency of the organic EL element is improved, the emission spectrum distribution is sharpened, and the color purity of the emission color is improved.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing an organic EL device having a two-layer structure.

FIG. 2 is a structural diagram showing an organic EL device having a three-layer structure.

FIG. 3 is a graph showing response characteristics of current and luminance with respect to voltage of the organic EL element of Example 1.

FIG. 4 shows an EL spectrum distribution (a) of the organic EL device of Example 1 and a PL spectrum distribution (b) of its guest molecule.
It is.

FIG. 5 shows an EL spectrum distribution (a) of the organic EL device of Example 2 and a PL spectrum distribution (b) of its guest molecule.
It is.

FIG. 6 shows an EL spectrum distribution (a) of the organic EL device of Example 3 and a PL spectrum distribution (b) of its guest molecule.
It is.

FIG. 7 shows an EL spectrum distribution (a) of the organic EL device of Example 4 and a PL spectrum distribution (b) of its guest molecule.
It is.

FIG. 8 shows an EL spectrum distribution (a) of the organic EL device of Example 5 and a PL spectrum distribution (b) of its guest molecule.
It is.

FIG. 9 shows an EL spectrum distribution (a) of the organic EL device of Example 6 and a PL spectrum distribution (b) of its guest molecule.
It is.

FIG. 10 shows an EL spectrum distribution (a) of the organic EL device of Example 7 and a PL spectrum distribution (b) of its guest molecule.

FIG. 11 shows an EL spectrum distribution (a) of the organic EL device of Example 8 and a PL spectrum distribution (b) of its guest molecule.

FIG. 12 shows an EL spectrum distribution (a) of the organic EL device of Example 9 and a PL spectrum distribution (b) of its guest molecule.

[Description of Signs of Main Parts]

 Reference Signs List 1 metal electrode (cathode) 2 transparent electrode (anode) 3 light emitting layer 4 organic hole transport layer 5 electron transport layer 6 glass substrate

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Jun Funaki 6-1-1, Fujimi, Tsurugashima-shi, Saitama Pioneer Corporation General Research Institute (56) References JP-A-3-37292 (JP, A) Hei 2-247257 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 11/06 640 CA (STN) REGISTRY (STN)

Claims (7)

(57) [Claims] 1. An anode, a hole transport layer comprising an organic compound,
A light emitting layer made of an organic compound and a cathode are sequentially laminated, and the light emitting layer is a pyrimidopyrimidine derivative represented by Chemical Formula 1. 中 In Chemical Formula 1, R ₁ , R ₂ , R _{3 and} R ₄ each independently represent a hydrogen atom, a halogen atom or a group represented by Chemical Formula 2, In Chemical Formula 2, R _{5 and} R ₆ are each independently a hydrogen atom,
An organic electroluminescent device comprising an alkyl group, an aryl group, or｝, which represents an atom or a group in which R ₅ and R ₆ together form a cycloalkyl group or a heterocyclic group. 2. The pyrimidopyrimidine derivative is represented by the following chemical formula 3: _2. The organic electroluminescent device according to claim 1, wherein in Formula 3, R _{1 and} R ₂ are different from each other and each represents a hydrogen atom, a halogen atom, or a group represented by Formula 2. 2. 3. The pyrimidopyrimidine derivative is represented by the following chemical formula 4: 中 In Chemical Formula 4, R _{5 and} R ₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, or an atom or group in which R ₅ and R ₆ together form a cycloalkyl group or a heterocyclic group. 2. The organic electroluminescent device according to claim 1, wherein Δ represents 4. The organic electroluminescence device according to claim 1, wherein a hetero atom contained in the heterocyclic group is nitrogen, oxygen or sulfur. 5. The pyrimidopyrimidine derivative, wherein the hydrogen atom of the alkyl group, the aryl group, the alkylene group, and the arylene group in the group represented by the chemical formula 2 is an alkyl group, an alkoxy group, an aryl group, or an aryloxy group. 5. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device is substituted with a halogen atom. 6. The light-emitting layer contains an organic host substance having an electron transporting property, and an atomic ratio of the organic host substance having an electron transporting property is larger than an atomic ratio of the pyrimidopyrimidine derivative. The organic electroluminescence device according to claim 1. 7. The organic electroluminescence device according to claim 1, wherein an organic electron transport layer is provided between the cathode and the light emitting layer.