JP5609761B2 - Ptycene-based compound, organic electroluminescence device and lighting device - Google Patents

Description

  The present invention relates to a petitcene-based compound, an organic electroluminescence element, and a lighting device.

Organic electroluminescence elements (hereinafter abbreviated as OLED elements, organic EL elements, etc.) can be driven at a low voltage of several volts to several tens of volts, and are self-luminous so that they have a wide viewing angle and visibility. It is a high-quality, thin-film, solid-state device, so it is attracting attention as a display or lighting application from the viewpoints of space saving, energy saving, and portability. Have begun to do.
However, for the realization and widespread use of large screen displays or lighting that replaces cold cathode fluorescent lamps, the luminous efficiency is dramatically higher than the current situation, the luminous lifetime is long, and there are no defects such as discoloration of the luminescent color over time. Development of devices is desired.

In recent years, phosphorescent materials have been actively studied as a technique for increasing luminous efficiency.
Phosphorescent materials are attracting much attention as illumination applications because they may have almost the same luminous efficiency as cold cathode fluorescent lamps.
On the other hand, there has been a report of an organic EL device using a compound having a highly condensed nitrogen-containing heterocycle aiming at high efficiency of light emission (for example, see Patent Document 1). When applied to a light-emitting element, defects such as light emission efficiency, light emission lifetime, and discoloration of the emitted color over time were not satisfactory.
In addition, as materials in which nitrogen atoms are replaced with other atoms, materials using silicon atoms (for example, see Patent Documents 2, 3 and 4) and materials using phosphorus atoms (for example, see Patent Document 5) have been reported. ing.
Although these materials have made some progress in terms of luminous efficiency, especially when applied to blue phosphorescent light emitting devices, they are not at a satisfactory level for defects such as emission lifetime and discoloration of the emitted color over time. It was.

JP 2010-87496 A Japanese Patent No. 2003-243178 Japanese Patent No. 4136352 JP 2010-64976 A JP 2009-179585 A

  Accordingly, a main object of the present invention is to provide a novel compound used for an organic electroluminescence device, which can improve the light emission efficiency and the light emission lifetime, and can prevent the discoloration of the emitted color over time. In addition, it is to provide an organic electroluminescence element and a lighting device using the compound.

In order to solve the above problems, according to the present invention,
A petitcene-based compound contained in an organic layer of an organic electroluminescence device,
Provided is a petitcene-based compound represented by the general formula 1 or the general formula 2.

In General Formula 1 or General Formula 2, “X” represents C—R 1 and “Y” represents N, P═Z or Si—R 3 . “Z” represents O, S, Se or Te, and “R1” and “R3” represent an aromatic hydrocarbon ring group or an aromatic heterocyclic group. “A1 to A4” represents C—R4 . “R4” is a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group or a silyl group. Represents a group. “E1 to E3” represent an atomic group necessary for forming a thiophene ring or a furan ring together with two carbon atoms bonded to X and Y.

  According to the present invention, it is possible to improve the light emission efficiency and the light emission lifetime, and to prevent discoloration of the emitted color over time.

It is the schematic diagram which showed an example of the display apparatus. It is a schematic diagram of the display part of the display apparatus of FIG. It is the schematic of an illuminating device. It is sectional drawing of the illuminating device of FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

The OLED element of the present invention is an OLED element having at least one organic layer including a light emitting layer between a pair of electrodes (for example, between an anode and a cathode), and at least one of the organic layers. The novel petitene type compound represented by the general formula 1 or the general formula 2 is contained.
The novel petitene compound of the present invention is a compound in which three aromatic rings (aromatic hydrocarbon ring or aromatic heterocycle) are sterically condensed.
The present inventors consider the effects obtained when the OLED device of the present invention contains a novel petitene-based compound represented by the general formula 1 or 2 in at least one of the organic layers as follows. Yes.
Conventionally known compounds containing three or more polycondensed rings used in OLED elements are planar, have large molecular distortion, and are unstable in light and heat, whereas the new putisene of the present invention is used. Since the aromatic compound sterically condenses with the aromatic compound, it is possible to form a more stable condensed ring, and it is considered that the lifetime of light emission of the OLED element can be achieved.
At the same time, the condensed ring is not too rigid and not too flexible, the steric structure can be fixed and maintained at an appropriate level, and the extent of conjugation can be adjusted appropriately for π-conjugation. Therefore, the new petitcene-based compound according to the present invention has high stability and, when included in an OLED element, appropriately interacts with materials contained in the same layer or adjacent layers, and optimizes charge transfer. It is estimated that it is possible to control.
From the above, when the present inventors use the novel petitene-based compound according to the present invention in an OLED element and a lighting device including the same, high luminous efficiency, long light emission lifetime, discoloration of luminescent color over time, etc. It is assumed that defect reduction can be achieved.

<Ptycene-based compound>
The novel petitcene compound of the present invention will be described in detail.
The petitene-based compound is represented by General Formula 1 or General Formula 2.

In the general formulas 1 and 2, “X” represents C—R1, and “Y” each independently represents C—R2, N, P═Z or Si—R3.
In Y in the general formulas 1 and 2, “Z” represents O, S, Se or Te, preferably O or S.
In X and Y in the general formulas 1 and 2, “R1”, “R2”, and “R3” represent an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
Examples of the aromatic hydrocarbon ring group include phenyl group, chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, And biphenylyl group.
Among them, preferred examples of the aromatic hydrocarbon ring group include a phenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, a biphenylyl group, and a fluoronyl group, and particularly preferred are a phenyl group, a naphthyl group, and a fluorenyl group.
These groups may further have a substituent described later.
Examples of the aromatic heterocyclic group include pyridyl group, pyrimidyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl). Group, 1,2,3-triazol-1-yl group, etc.)), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl Group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbolyl group (wherein one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl group, triazinyl group, Quinazolinyl group, phthalazini Group, and the like.
Among them, preferred examples of the aromatic heterocyclic group include a pyridyl group, a pyrimidyl group, an imidazolyl group, a pyrazolyl group, a thienyl group, a quinolyl group, a dibenzofuryl group, a carbazolyl group, a carbolinyl group, and a diazacarbolinyl group. Includes a pyridyl group, a pyrimidyl group, a pyrazolyl group, a dibenzofuryl group, a carbazolyl group, a carbolinyl group, and a diazacarbazolyl group.
These groups may further have a substituent described later.

In the general formula 1 and general formula 2, the aromatic hydrocarbon ring group and the aromatic heterocyclic group represented by R1 to R3 each may have an alkyl group (for example, methyl group, ethyl group) Group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group etc.), Alkenyl group (for example, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.) ), Aromatic hydrocarbon group (also called aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., for example, phenyl group, Lorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, triphenylenyl group, biphenylyl group, etc.), aromatic heterocyclic group ( For example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, azacarbazolyl group (carbazole ring of the above carbazolyl group) Any one of carbon atoms constituting one or more carbon atoms is replaced by a nitrogen atom), benzofuryl group, dibenzofuryl group, azadibenzofuryl group (any carbon atom constituting the dibenzofuran ring of the dibenzofuryl group) Benzothienyl group, indolyl group, dibenzothienyl group, benzoimidazolyl group, oxazolyl group, benzoxazolyl group, quinoxalinyl group, isoxazolyl group, isothiazonyl group, indolocarbazolyl Group, hexaazatriphenylenyl group, benzodifuranyl group, benzodithienyl group, phosphor group, silylyl group, boryl group, bipyridyl group, etc., heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.) ), Alkoxy groups (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy groups (for example, cyclopentyloxy group, cyclohexyloxy group, etc.) , Aryloxy groups (for example, phenoxy group, naphthyloxy group, etc.), alkylthio groups (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio groups (for example, Cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyl) Oxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfur group) Nyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.) An acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group) Etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, Silcarbonyloxy group, phenylcarbonyloxy group, acryloyl group, methacryloyl group, etc.), amide group (eg, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonyl) Amino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group) Propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexyl Aminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido) Group, dodecylureido group, phenylureido group naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group) Group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethyl) Sulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), Amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, phenylamino group, diphenylamino group, naphthylamino group, 2 -Pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophene) Cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group), phosphono group, hydroxy group, etc. It is done.
These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

“A1 to A4” in the general formula 1 represents N or C—R4.
“R4” in C—R4 is a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkylthio group, a cycloalkylthio group, It represents an arylthio group or a silyl group, and specific examples thereof include those described in the above substituents.
R4 is preferably a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group or an alkoxy group.
The number of N represented by A1 to A4 is preferably 0, 1 or 2.

In the general formula 2, “E1 to E3” represents an atomic group necessary for forming an aromatic hetero five-membered ring together with two carbon atoms bonded to X and Y.
(I) when E1 and E3 are O or S and E2 is C-R5 or N; (ii) when E1 and E3 are C-R5 or N and E2 is O or S; or (iii) The case where E1-E3 is N or N-R6 is preferable.
In General Formula 2, “R5” and “R6” of E1 to E3 are a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group. Represents a group, an alkylthio group, a cycloalkylthio group, an arylthio group or a silyl group, and specific examples of each group include the same groups as those described above for the substituent.
A plurality of R3 and R4 may be bonded to each other to form a ring.
As the aromatic hetero five-membered ring in the general formula 2, the oxazole ring, oxadiazole ring, oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole ring, isothiazole ring, thiophene ring, furan ring, pyrrole And a ring, an imidazole ring, a pyrazole ring, and a triazole ring.
These groups may further have the above substituents.

  Hereinafter, although the specific example of the novel petitene type compound of this invention represented by General formula 1 or 2 is given, this invention is not limited to these.

Hereinafter, although the synthesis example of the novel petitcene-type compound of this invention is given, this invention is not limited to these.
<< Synthesis Example 1: Synthesis of Compound P-1 >>

3.47 g (10.0 mmol) of raw material A was dissolved in 50 ml of THF, 1.18 g (5.00 mmol) of hexachloroethane and 30 mg (0.17 mmol) of palladium chloride were added, and the mixture was stirred at room temperature for 4 hours. The solvent was concentrated under reduced pressure to obtain Intermediate B.
Next, Intermediate B was dissolved in 50 ml of diethyl ether, and the internal temperature was cooled to -70 ° C.
Next, a diethyl ether solution (30 ml) (10.0 mmol) of a separately synthesized carbazole-lithio compound (1) was slowly added dropwise while maintaining the internal temperature at −65 ° C. or lower. After the dropwise addition, the temperature was returned to room temperature and the mixture was further stirred for 1 hour. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent toluene: methylene chloride = 100: 1) to obtain 5.46 g (yield 93%) of Exemplary Compound P-1.
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

<< Synthesis Example 2: Synthesis of Compound P-2 >>

2.88 g (10.0 mmol) of raw material C was dissolved in 50 ml of THF, 1.33 g (10.0 mmol) of N-chlorosuccinimide was added, and the mixture was stirred at room temperature for 2 hours. The solvent was concentrated under reduced pressure to obtain Intermediate D.
Next, Intermediate D was dissolved in 50 ml of diethyl ether, and the internal temperature was cooled to -70 ° C.
Next, a diethyl ether solution (30 ml) (10.0 mmol) of the carbazole-lithio compound (1) synthesized separately was slowly added dropwise while maintaining the internal temperature at −65 ° C. or lower. After the dropwise addition, the temperature was returned to room temperature and the mixture was further stirred for 2 hours. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent toluene: methylene chloride = 55: 1) to obtain 5.11 g (yield 97%) of exemplary compound P-2.
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

<< Synthesis Example 3: Synthesis of Compound P-4 >>

2.55 g (10.0 mmol) of raw material E was dissolved in 50 ml of chloroform, 1.33 g (10.0 mmol) of N-chlorosuccinimide was added, and the mixture was stirred at room temperature for 2 hours. The solvent was concentrated under reduced pressure to obtain Intermediate F.
Next, the intermediate F was dissolved in 50 ml of N, N-dimethylformamide, and 1.67 g (10.0 mmol) of carbazole, 3 g of copper powder and 2.76 g (20.0 mmol) of potassium carbonate were added, and the internal temperature was 154 ° C. Stirring was performed for 12 hours.
The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent toluene: methylene chloride = 80: 1) to obtain 4.01 g (yield 95%) of Exemplary Compound P-4.
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

<< Synthesis Example 4: Synthesis of Compound P-13 >>

2.36 g (10.00 mmol) of the raw material G was dissolved in 50 ml of THF, 1.70 g (5.01 mmol) of hexachloroethane and 30 mg (0.18 mmol) of palladium chloride were added, and the mixture was stirred at room temperature for 10 hours. The solvent was concentrated under reduced pressure to obtain Intermediate H.
Next, Intermediate H was dissolved in 50 ml of diethyl ether, and the internal temperature was cooled to -70 ° C.
Next, a diethyl ether solution (30 ml) (10.0 mmol) of a separately synthesized carbazole-lithio derivative (1) was slowly added dropwise while maintaining the internal temperature at −75 ° C. or lower. After the dropwise addition, the temperature was returned to room temperature and the mixture was further stirred for 1 hour.
The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent n-hexane: toluene = 4: 1) to obtain 7.03 g (yield 93%) of exemplary compound P-13. .
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

<< Synthesis Example 5: Synthesis of Compound P-17 >>

3.80 g (10.0 mmol) of Intermediate B of Synthesis Example 1 was dissolved in 50 ml of diethyl ether, and the internal temperature was cooled to -70 ° C.
Next, a diethyl ether solution (50 ml) (10.0 mmol) of a separately synthesized carbazole-lithio compound (2) was slowly added dropwise while maintaining the internal temperature at −68 ° C. or lower. After the dropwise addition, the temperature was returned to room temperature and the mixture was further stirred for 1 hour.
The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent toluene: methylene chloride = 120: 1) to obtain 5.48 g (yield 93%) of Exemplary Compound P-17.
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

<< Synthesis Example 6: Synthesis of Compound P-22 >>

3.64 g (10.0 mmol) of raw material I was dissolved in 50 ml of THF, 1.70 g (5.01 mmol) of hexachloroethane and 30 mg (0.18 mmol) of palladium chloride were added, and the mixture was stirred at room temperature for 8 hours. The solvent was concentrated under reduced pressure to obtain Intermediate J.
Next, the intermediate J was dissolved in 50 ml of diethyl ether, and the internal temperature was cooled to -70 ° C.
Next, a diethyl ether solution (30 ml) (10.0 mmol) of a separately synthesized carbazole-lithio derivative (1) was slowly added dropwise while maintaining the internal temperature at −75 ° C. or lower. After the dropwise addition, the temperature was returned to room temperature and the mixture was further stirred for 1 hour.
The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent n-hexane: toluene = 10: 1) to obtain 6.03 g (yield 99%) of exemplary compound P-22. .
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

<< Synthesis Example 7: Synthesis of Compound P-38 >>

4.84 g (10.0 mmol) of raw material K was dissolved in 70 ml of chloroform, 1.33 g (10.0 mmol) of N-chlorosuccinimide was added, and the mixture was stirred at room temperature for 2 hours. The solvent was concentrated under reduced pressure to obtain Intermediate L.
Next, the intermediate L was dissolved in 60 ml of diethyl ether, and the internal temperature was cooled to -78 ° C.
Next, a diethyl ether solution (30 ml) (10.0 mmol) of a separately synthesized carbazole-lithio compound (1) was slowly added dropwise while maintaining the internal temperature at −65 ° C. or lower. After the dropwise addition, the temperature was returned to room temperature and the mixture was further stirred for 1 hour.
The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent n-hexane: toluene = 15: 1) to obtain 7.02 g (yield 97%) of exemplary compound P-38. .
The structure was identified by nuclear magnetic resonance ( ¹ H-NMR, ¹³ C-NMR, etc.) and MASS spectrum (mass spectrometry).

In addition, petitcene compounds other than those shown in Synthesis Examples 1 to 7 were synthesized in the same manner.
In addition, in the synthesis | combination of the novel petitcene type compound of this invention, the reference literature is enumerated below.
(A) Angew. Chem. internet. Edit./Vol. 2 (1963) 396 (b) J. MoI. Chem. Soc. Commn. 1993, pages 1850-1852 (c) Tetrahedron Lett. , 50 (2009) 5080-5082 (d) Chem. Ber. 118, page 3892 (1985)
(E) J.M. Org. Chem. , 1936, VOL.1, pp. 170-175.

The function of the novel petitene compound of the present invention represented by the general formula 1 or 2 contained in at least one of the organic layers constituting the organic EL device of the present invention is not limited, It may be contained in any layer within the organic layer.
The petitene-based compound is preferably a light-emitting layer, a hole transport layer, an electron transport layer from the viewpoint of obtaining the effects described in the present invention (high light emission efficiency, long light emission lifetime, no or little discoloration over time). From the viewpoint of being contained in either of the hole blocking layer and responsible for hole transport, it is preferably contained in the light emitting layer and the hole transporting layer, and most preferably contained in the light emitting layer.
In particular, when the petitcene compound is contained in the light emitting layer, the novel petitene compound of the present invention is preferably used as a light emitting host compound (also referred to as a host material).
Each organic layer constituting the organic EL device of the present invention may be composed solely of the novel petitene-based compound of the present invention, or the petitcene-based compound is mixed with other materials and composed of a mixture thereof. Also good.

<< Constitutional layer of OLED element (organic EL element) >>
The constituent layers of the OLED element (organic EL element) of the present invention will be described.
The OLED element (organic EL element) of the present invention has a pair of electrodes (cathode and anode) on a substrate, and has an organic layer including a light emitting layer between both electrodes. In view of the properties of the light emitting element, at least one of the anode and the cathode is preferably transparent.
Hereinafter, although the preferable specific example of the layer structure of the OLED element (organic EL element) of this invention is shown below, this invention is not limited to these.
(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode

In the OLED element (organic EL element) of the present invention, the light emitting maximum wavelength of the blue light emitting layer is preferably 430 nm to 480 nm, and the green light emitting layer preferably has a light emitting maximum wavelength of 510 nm to 550 nm, and the red light emitting layer. Is preferably a monochromatic light emitting layer having a light emission maximum wavelength in the range of 600 nm to 640 nm, and is preferably a display element using these.
Further, a white light emitting element may be formed by laminating at least three of these light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers.
The OLED element of the present invention is preferably a white light emitting element, and is preferably a lighting device using these.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May also be the interface between the light emitting layer and the adjacent layer.
The total thickness of the light emitting layer is not particularly limited, but is preferably from the viewpoint of the uniformity of the film and the application of unnecessary high voltage during light emission and the improvement of the stability of the emission color with respect to the driving current. It is adjusted to the range of 2 nm to 5 μm, more preferably adjusted to the range of 2 nm to 200 nm, and particularly preferably adjusted to the range of 10 nm to 40 nm.

The light emitting layer of the OLED device of the present invention contains a light emitting dopant (such as a phosphorescent dopant (also referred to as a phosphorescent dopant group) or a fluorescent dopant) compound and a host compound.
In particular, the light emitting layer preferably contains a blue phosphorescent dopant compound and a host compound.

(1) Luminescent dopant compound A luminescent dopant compound is demonstrated.
As the luminescent dopant compound, a phosphorescent dopant compound or a fluorescent dopant compound can be used. In the present invention, a phosphorescent dopant compound is preferably used, and a blue phosphorescent dopant compound is more preferably used.

(1.1) Phosphorescent dopant compound The phosphorescent dopant compound according to the present invention will be described.
The phosphorescent dopant compound according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant compound is a compound that emits phosphorescence at room temperature (25 ° C.). A preferred phosphorescence quantum yield is 0.1 or more, although it is defined as 0.01 or more compounds.
The above phosphorescence quantum yield can be measured by the method described in Spectral II, page 398 (1992 edition, Maruzen) of 4th edition Experimental Chemistry Course 7. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant compound according to the present invention only needs to achieve the above phosphorescence yield of 0.01 or more in any solvent.

There are two types of emission principles of the phosphorescent dopant compound.
One of them is the recombination of carriers on the host compound to which carriers are transported, generating an excited state of the luminescent host compound, and transferring this energy to the phosphorescent dopant to obtain light emission from the phosphorescent dopant. The energy transfer type.
The other is a carrier trap type in which the phosphorescent dopant compound itself becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant compound is obtained.
In any case, the excited state energy of the phosphorescent dopant compound is lower than the excited state energy of the host compound, which is a condition for obtaining good light emission.

  Although the specific example of the well-known compound used as a phosphorescence dopant below is shown, this invention is not limited to these.

(1.2) Fluorescent dopant compound Examples of the fluorescent dopant compound include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squarylium dyes, oxobenzoanthracene dyes, fluorescein dyes, rhodamine dyes, Examples include pyrylium dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

(2) Luminescent host compound (also referred to as host material, host compound, luminescent host, etc.)
The light emitting host compound used in the light emitting layer and the light emitting unit of the OLED device of the present invention is phosphorescent at a room temperature (25 ° C.) with a mass ratio in the layer of 20% or more among the compounds contained in the light emitting layer. The quantum yield is defined as a compound having a value of less than 0.1, and preferably the phosphorescence quantum yield is less than 0.01.
The light emitting host compound preferably has a mass ratio in the layer of 20% or more among the compounds contained in the light emitting layer.
As the host compound, it is preferable to use the novel petitene-based compound of the present invention. The host compound may be composed of one of the novel petitene compounds of the present invention alone, or may be composed of a combination of a plurality of the petitene compounds.
By using a plurality of types of host compounds, it is possible to adjust the movement of carriers, and the performance of the OLED element can be further increased. In addition, by using a plurality of known compounds used as the phosphorescent dopant, it is possible to mix different light emission, thereby obtaining an arbitrary emission color.
The light emitting host used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). One or a plurality of such compounds may be used.

Conventionally known host compounds may be used in combination with the host compound.
Known light-emitting host compounds typically include those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, carboline derivatives, And diazacarbazole derivatives.
A known host compound that may be used in combination is preferably a compound that has a hole transporting ability and an electron transporting ability, prevents a long wavelength of light emission, and has a high Tg (glass transition temperature).
Specific examples of known host compounds include, but are not limited to, compounds described in the following documents.
JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

Next, an injection layer, a blocking layer, a transport layer and the like used as a constituent layer of the OLED element of the present invention will be described.
<Injection layer: electron injection layer, hole transport layer>
The injection layer can be provided as necessary, and includes an electron injection layer and a hole injection layer, and as described above, between the anode and the light emitting layer or the hole transport layer, or between the cathode and the light emitting layer or the electron transport layer. It may be present between.
An injection layer is a layer provided between an electrode and an organic layer to reduce drive voltage and improve light emission brightness. “OLED element and its forefront of industrialization (November 30, 1998, issued by NTS)” Chapter 2 “Electrode Materials” (pages 123 to 166) of the second edition of the same, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).
The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45579, JP-A-9-260062, JP-A-8-288069, and the like, and representative examples thereof include copper phthalocyanine. Phthalocyanine buffer layers, oxide buffer layers typified by vanadium oxide, amorphous carbon buffer layers, polymer buffer layers using conductive polymers such as polyaniline (emeraldine) and polythiophene, and the like.
Details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium or aluminum Metal buffer layer represented by lithium fluoride, alkali metal compound buffer layer represented by lithium fluoride, alkaline earth metal compound buffer layer represented by magnesium fluoride, oxide buffer layer represented by aluminum oxide, etc. It is done.
The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
As described above, the blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film.
The blocking layer is, for example, pages 237 of JP-A Nos. 11-204158 and 11-204359, and “OLED elements and the forefront of industrialization (November 30, 1998, issued by NTS Corporation)”. There is a hole blocking layer (hole blocking layer).
The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes. By blocking hole transport, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.
The hole blocking layer of the OLED element (organic EL element) of the present invention is preferably provided adjacent to the light emitting layer.
The hole blocking layer preferably contains the carbazole derivative, carboline derivative, diazacarbazole derivative, or the like mentioned as the host compound.

Moreover, when it has several light emitting layers from which luminescent color differs, it is preferable that the light emitting layer with the shortest light emission maximum wavelength is the closest to an anode among all the light emitting layers. In such a case, it is preferable to additionally provide a hole blocking layer between the shortest wave light emitting layer and the light emitting layer next to the anode next to the light emitting layer. Further, it is preferable that 50% by mass or more of the compound of the hole blocking layer provided at the position is 0.3 eV or more larger than the ionization potential of the host compound of the shortest wave emitting layer.
The ionization potential is defined as the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by, for example, the following method.
(1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit converted value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.
(2) It can also be determined by a method of direct measurement by photoelectron spectroscopy. Yes. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki.

On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material having a function of transporting holes and a very small ability to transport electrons, and transporting electrons while transporting holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed.
The film thickness of the hole blocking layer and electron blocking layer according to the present invention is preferably 3 nm to 100 nm, and more preferably 5 nm to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes. In a broad sense, the hole transport layer and the electron blocking layer can be regarded as being included in the hole transport layer.
The hole transport layer can be provided as a single layer or a plurality of layers.
The hole transport material has any of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers and conductive polymers (polymers and oligomers), particularly thiophene oligomers.

The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound. Further, the OLED element material of the present invention can also be preferably used.
Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4 '. -Diamine (TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD), 4,4 ', 4 "-tris [N- (3-methylphenyl) ) -N-phenylamino] triphenylamine (MTDATA).
Furthermore, a polymer material in which these materials are introduced into a polymer chain or a polymer main chain can also be used.
Inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole transport material.
JP-A-11-251067, J. Org. Huang et al. A p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used.

The hole transport layer is formed by thinning the hole transport material as described above by, for example, a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. be able to.
Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-5 micrometers, Preferably it is 5 nm-200 nm.
Further, the hole transport material may have a single layer structure composed of a plurality of types of materials.
Alternatively, a hole transport layer having a high p property doped with impurities can be used.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer.
The electron transport layer can be provided as a single layer or a plurality of layers.
An electron transport material (also serving as a hole blocking material) used for the electron transport layer adjacent to the cathode side with respect to the light emitting layer may have a function of transmitting electrons injected from the cathode to the light emitting layer. As the material, any one of conventionally known compounds can be selected and used. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthra Examples include quinodimethane and anthrone derivatives, oxadiazole derivatives, and the like.
Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.
In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material. In addition, phthalocyanine materials and derivatives thereof can also be preferably used as the electron transport material.
In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and hole transport layer Can also be used as an electron transporting material.

The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method.
Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm.
The electron transport layer may have a single layer structure composed of one or more of the above materials.
Further, an electron transport layer having a high n property doped with impurities can also be used.

"anode"
As the anode in the OLED element, an electrode material made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a high work function (4 eV or more) is preferably used.
Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.
Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.
For the anode, a thin film may be formed by vapor deposition or sputtering of these electrode materials, and a pattern may be formed through a photolithography method or a mask.
Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used.
When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less.
Further, although the film thickness depends on the material, it is usually in the range of 10 nm to 1000 nm, and preferably in the range of 10 nm to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is 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, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.
The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.
The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm.
In order to transmit the emitted light, if either the anode or the cathode of the OLED element is transparent or translucent, the light emission luminance is improved and it is convenient.
Moreover, after producing the said metal by the film thickness of 1 nm-20 nm to a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the OLED device (organic EL device) of the present invention, there is no particular limitation on the type of glass, plastic, etc. It may be transparent or opaque.
When extracting light from the support substrate side, the support substrate is preferably transparent.
Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film.
A particularly preferable support substrate is a resin film capable of giving flexibility to the OLED element (organic EL element).

Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellulose esters (cellulose acetate propionate (CAP), cellulose acetate phthalate (TAC), and cellulose nitrate. Etc.) or derivatives thereof, polyvinylidene chloride, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyethersulfone (PES), polyphenylene sulfide, polysulfones, polyether Imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic Alternatively polyarylates, and cycloolefin resins such as ARTON (manufactured by JSR) or APEL (manufactured by Mitsui Chemicals).
On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. The permeability is 10 ⁻³ cm ³ / (m ² · 24 h · atm) (1 atm is 1.01325 × 10 ⁵ Pa) or less, and the water vapor permeability is 10 ⁻³ g / (m ² · 24 h) or less. It is preferably a high barrier film, and more preferably has a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less.

As a material for forming the barrier film, any material may be used as long as it has a function of suppressing intrusion of moisture or oxygen that causes deterioration of the element. For example, silicon oxide, silicon dioxide, silicon nitride, or the like is preferably used. it can. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.
The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method and the like can be used, and an atmospheric pressure plasma polymerization method is particularly preferable.

Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.
The external extraction quantum efficiency at room temperature of light emission of the OLED element (organic EL element) of the present invention is preferably 1% or more, more preferably 5% or more.
Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the OLED element / the number of electrons sent to the OLED element × 100.
In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the OLED element into multiple colors with a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the OLED element is preferably 480 nm or less.

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, or a support substrate with an adhesive agent can be mentioned, for example.
As a sealing member, it should just be arrange | positioned so that the display area | region of an OLED element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.
Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.
In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned.
Further, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the method is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.
In addition, when using a thermosetting adhesive, since an OLED element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.
In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.

Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials.
The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.
In the gap between the sealing member and the display area of the OLED element, it is preferable to inject an inert gas such as nitrogen or argon, an inert liquid such as fluorinated hydrocarbon, or silicon oil in the gas phase and the liquid phase. . A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.
Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, etc.), metal halides. Perchloric acids and the like, and anhydrous salts are preferably used.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when sealing is performed by the sealing film, it is preferable to provide a protective film and a protective plate.
As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used. It is preferable to use a film.

《Light extraction》
The OLED element emits light inside a layer having a higher refractive index than air (refractive index is about 1.7 to 2.1), and only 15% to 20% of the light generated in the light emitting layer can be extracted. Is generally said.
This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.
As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

In the present invention, these methods can be used in combination with the OLED element of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, a transparent electrode A method of forming a diffraction grating between any of the layers and the light emitting layer (including between the substrate and the outside) can be suitably used. In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.
When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.
Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.
The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency.
This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction, such as first-order diffraction or second-order diffraction, and light generated from the light-emitting layer. The light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating in any layer or medium (in the transparent substrate or transparent electrode). It is intended to be taken out.
The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.
However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.
As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.
The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The OLED element of the present invention is processed on the light extraction side of the substrate, for example, by providing a microlens array-like structure, or combined with a so-called condensing sheet, so that the OLED element is arranged in a specific direction, for example, the element light emitting surface. On the other hand, the brightness | luminance in a specific direction can be raised by condensing in a front direction.
As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.
As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.
Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<< Production Method of OLED Element (Organic EL Element) >>
As an example of the method for producing the OLED device of the present invention, a method for producing an OLED device comprising an anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.
First, a desired electrode material, for example, a thin film made of an anode material is formed on an appropriate support substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm. To do.

Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking layer, which are OLED element materials, is formed thereon.
As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above. In view of the above, in the present invention, a wet process is preferable, and film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is particularly preferable.
Examples of the liquid medium for dissolving or dispersing the OLED element material of the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, mesitylene, Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used.
Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm, and a cathode is provided. Thus, a desired OLED element can be obtained.

Note that it is also possible to produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order by reversing the order of production.
When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 V to 40 V with the anode as + and the cathode as-. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<Application>
The OLED element (organic EL element) of the present invention can be used as a display device, a display, and various light sources.
For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Examples include, but are not limited to, a light source of a sensor, and the light source can be preferably used for a backlight of a liquid crystal display device and a light source for illumination.
In the OLED element (organic EL element) of the present invention, patterning may be performed by a metal mask, an inkjet printing method, or the like at the time of film formation, if necessary. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.
The light emission color of the OLED element (organic EL element) of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (Edited by the Japan Color Society, University of Tokyo Press, 1985). The color measured when the result measured with a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates is determined.
Further, when the OLED element (organic EL element) of the present invention is a white light emitting element, white means the CIE 1931 color system at 1000 cd / m ² when the front luminance at 2 ° viewing angle is measured by the above method. Is in the region of X = 0.33 ± 0.07, Y = 0.33 ± 0.1.

<< Display device and lighting device >>
An example of a display device (see FIGS. 1 and 2) and an illumination device (see FIGS. 3 and 4) using the OLED element (organic EL element) of the present invention will be described based on the drawings.

FIG. 1 is a schematic view showing an example of a display device composed of organic EL elements.
FIG. 1 is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.
As shown in FIG. 1, the display 1 includes a display unit A having a plurality of pixels and a control unit B that performs image scanning of the display unit A based on image information.
The control unit B is electrically connected to the display unit A.
The control unit B sends a scanning signal and an image data signal to each of the plurality of pixels based on image information from the outside, and the pixels for each scanning line sequentially emit light according to the image data signal by the scanning signal to perform image scanning. The image information is displayed on the display unit A.

FIG. 2 is a schematic diagram of the display unit A.
As shown in FIG. 2, the display unit A has a wiring unit including a plurality of scanning lines 5 and data lines 6 and a plurality of pixels 3 on a substrate.
The main members of the display unit A will be described below.
FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).
Each of the scanning lines 5 and the plurality of data lines 6 in the wiring portion is made of a conductive material.
The scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice pattern, and are connected to the pixels 3 at the orthogonal positions (details are not shown).
When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data.
According to the display unit A, full-color display can be performed by appropriately arranging pixels in which the emission color is a red region, a green region, and a blue region on the same substrate.

FIG. 3 shows a schematic diagram of the illumination device.
As shown in FIG. 3, the organic EL element 101 is covered with a glass cover 102. The sealing operation with the glass cover 102 is preferably a glove box (purity) in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere. 99.999% or higher atmosphere of high purity nitrogen gas).
FIG. 4 shows a cross-sectional view of the lighting device.
As shown in FIG. 4, the lighting device includes a cathode 105, an organic EL layer 106, and a glass substrate 107 with a transparent electrode.
In the lighting device, the glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.
In addition, compounds used for manufacturing the device are shown below.

<Production of sample>
(1) OLED element 1-1
Using a substrate in which ITO (indium tin oxide) is formed to a thickness of 200 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm, the ITO film is patterned to obtain a light emitting area of 50 mm × 50 mm, and an anode electrode (ITO) A transparent electrode) was prepared, ultrasonically cleaned with isopropyl alcohol, dried with nitrogen gas, and further subjected to UV ozone cleaning to prepare a transparent support substrate.
This transparent support substrate was put into a commercially available vacuum deposition apparatus, and after reducing the pressure to 4 × 10 ⁻⁴ Pa or less, CuPc (copper phthalocyanine) was deposited as a hole injection layer to provide a 20 nm hole injection layer.
Further subsequently, a hole transporting material HT-1 is deposited to a thickness of 20 nm to form a hole transporting layer, and the petitcene compound P-1 of the present invention as a host material and a blue phosphorescent dopant D-1 are formed thereon. A light emitting layer having a dopant concentration of 6% was deposited by 30 nm.
Further, the electron transport material ET-1 was deposited to 30 nm to form an electron transport layer, then lithium fluoride was deposited to 0.5 nm to form an electron injection layer, aluminum 120 nm was deposited to form a cathode, OLED element 1-1 "was produced.

(2) OLED elements 1-2 to 1-25
In the production of the OLED element 1-1, as shown in Table 1, the electron transport material, the host material, and the hole transport material were changed.
Otherwise, “OLED elements 1-2 to 1-25” were produced in the same manner.

<< Evaluation of Samples (OLED Elements 1-1 to 1-25) >>
In each of the OLED elements 1-1 to 1-25, the non-light-emitting surface is covered with a glass case, the peripheral portion is sealed with an epoxy-based adhesive, and an illumination device (planar lamp) as shown in FIGS. For each element, the following light emission efficiency, light emission lifetime, and discoloration (discoloration of the light emission color over time) were evaluated.

(1) Luminous efficiency About OLED elements 1-1 to 1-25, a constant current of ^2.5 mA / cm ² was applied, and the external extraction quantum efficiency at that time was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.
In addition, the value of efficiency sets the measured value of the OLED element 1-1 to 100 for the OLED elements 1-1 to 1-12, and the OLED element 1-13 for the OLED elements 1-13 to 1-18. Table 1 shows relative values when the measured value of OLED element 1-19 is set to 100 with respect to OLED elements 1-19 to 1-25.

(2) for emission lifetime OLED elements 1-1 through 1-25, the initial luminance 600 cd / ^{m 2} was driven at a constant current at a current giving, to measure the time to be 1/2 (300 cd / ^{m 2)} of the initial luminance, This was taken as a measure of stability.
As in the evaluation of efficiency, the stability value is 100 for the OLED elements 1-1 to 1-12, and the stability value is set to 100 for the OLED elements 1-1-13 to 1-18. On the other hand, the measured value of the OLED element 1-13 is 100, and for the OLED elements 1-19 to 1-25, the relative values when the measured value of the OLED element 1-19 is 100 are shown in Table 1. .

(3) The emission color of the color change with time OLED elements 1-1 through 1-25, the initial luminance 600 cd / ^{m 2} constant current was driven at a current giving, becomes the initial luminance 2/3 (400 cd / ^{m 2)} The change in emission color was observed visually, and the following four rank evaluations were performed on the observation results. The obtained results are shown in Table 1.
“◎”: No discoloration is observed. “◯”: Slightly yellowish.
“△”: Yellowish.
“×”: remarkably yellowish.

(4) Summary As shown in Table 1, OLED elements 1-1 to 1-7, 1-13 to 1-16, 1-19 to 1-22, and OLED elements 1-8 to 1-12, 1-17 to 1-18, 1-23 to 1-25, OLED elements 1-1 to 1-7, 1-13 to 1-16, and 1-19 to 1-22, which are examples of the present invention, It was excellent in all the characteristics of luminous efficiency, luminous lifetime and discoloration (discoloration of luminescent color with time).
From the above, it can be seen that the inclusion of a petitene-based compound in an organic layer such as a hole transport layer, a light emitting layer, or an electron transport layer is useful for improving light emission efficiency, light emission lifetime and discoloration prevention.

<< Preparation of White Light-Emitting Element X and White Illuminating Device X >>: Example of the Present Invention As a positive hole injection / transport layer in the same manner as in Example 1 above on a glass substrate with ITO patterned to 20 mm × 20 mm as an anode HT-1 was formed into a film having a thickness of 30 nm, and the petitcene compound P-1 and the dopants D-34 and D-39 were adjusted so that the deposition rate was 100: 0.5: 8, respectively. A light emitting layer having a thickness of 40 nm was provided.
Next, 10 nm of BAlq was formed as a hole blocking layer, and then 30 nm of Alq ₃ was formed to provide an electron transport layer.
Subsequently, lithium fluoride was formed to a thickness of 0.5 nm as an electron injection layer, and then 200 nm of aluminum was formed as a cathode to produce “white light emitting element X”.
Next, the non-light-emitting surface of the white light-emitting element X was covered with a glass case and sealed with an epoxy adhesive, and a flat lamp type “white illumination device X” as shown in FIGS. 3 and 4 was produced.
When the white lighting device X was energized, white light with luminous efficiency comparable to that of the cold cathode tube was obtained, and it was found that the white light emitting element X can be used as the lighting device. The light emission life of this lighting device was good, and no discoloration of the emission color over time was observed.

<< Preparation of White Light-Emitting Element Y and White Lighting Device Y >>: Example of the Present Invention On the same glass substrate used for the production of white light-emitting element X and white lighting device X of Example 2, poly (3, 4-Ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083), a pure solution diluted to 70%, was spin-coated at 3000 rpm for 30 seconds, dried, and then positively coated with a film thickness of 30 nm. A hole transport layer was provided.
Furthermore, the substrate with a hole transport layer was transferred to a nitrogen atmosphere, and petitcene compound P-16 (150 mg) and dopants D-8 (6.5 mg) and D-34 (4.0 mg) were added to 10 ml of toluene. The dissolved solution was spin-coated at 1000 rpm for 30 seconds, and then dried under vacuum at 100 ° C. to obtain a light emitting layer.
Subsequently, this substrate was transferred to a vacuum deposition apparatus, and Alq ₃ was formed to a thickness of 40 nm as an electron transport layer at a degree of vacuum of 4.0 × 10 ⁻⁴ Pa, and subsequently, lithium fluoride was set to a thickness of 0.04 as an electron injection layer. After forming to a thickness of 5 nm, aluminum having a thickness of 150 nm was formed as a cathode to produce “white light emitting element Y”.
Next, the non-light-emitting surface of the white light-emitting element Y was covered with a glass case and sealed with an epoxy adhesive, and a flat lamp type “white illumination device Y” as shown in FIGS. 3 and 4 was produced.
When the white lighting device Y was energized, almost white light was obtained, and it was found that the white light emitting element Y can be used as the lighting device. The light emission life of this lighting device was good, and no discoloration of the emission color over time was observed.

<< Production of Comparative White Light Emitting Elements y1 and y2 and Comparative White Lighting Devices y1 and y2 >>
In the production of the white light-emitting element Y and the white illumination device Y, the petitcene compound P-16 was replaced with the comparative compound 1 (150 mg) and the comparative compound 2 (150 mg), respectively, and other than that, the comparative white light emission was performed in the same manner. The elements y1 and y2 were produced, and then the comparative white lighting devices y1 and y2 were produced respectively.
When the white light-emitting elements y1 and y2 for comparison were respectively energized, white light emission was obtained from the white illumination devices y1 and y2, respectively, and the white light-emitting devices y1 and y2 had white light emission efficiency as an example of the present invention. It was found that it was about 80% of the white lighting device Y having the element Y, and the luminescent color changed to yellow over time.
From the above, according to the white light-emitting element Y which is an embodiment of the present invention, the white illumination device is superior in light emission efficiency, light-emission life and discoloration of the emitted color over time as compared with the comparative white light-emitting elements y1 and y2. It is clear that can be provided.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line A Display part B Control part 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water trapping agent

Claims (5)

A petitcene-based compound contained in an organic layer of an organic electroluminescence device,
A petitene-based compound represented by the general formula 1 or the general formula 2.

[In General Formula 1 or General Formula 2, "X" represents C-R1, and "Y" represents N, P = Z or Si-R3 . “Z” represents O, S, Se or Te, and “R1” and “R3” represent an aromatic hydrocarbon ring group or an aromatic heterocyclic group. “A1 to A4” represents C—R4 . “R4” is a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group or a silyl group. Represents a group.
“E1 to E3” represent an atomic group necessary for forming a thiophene ring or a furan ring together with two carbon atoms bonded to X and Y. ] A pair of electrodes;
At least one organic layer disposed between the pair of electrodes and including a light-emitting layer;
In an organic electroluminescence device having
At least one of the organic layers includes at least one kind of petitene-based compound represented by the general formula 1 or the general formula 2.

[In General Formula 1 or General Formula 2, "X" represents C-R1, and "Y" represents N, P = Z or Si-R3 . “Z” represents O, S, Se or Te, and “R1” and “R3” represent an aromatic hydrocarbon ring group or an aromatic heterocyclic group. “A1 to A4” represents C—R4 . “R4” is a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group or a silyl group. Represents a group. “E1 to E3” represent an atomic group necessary for forming a thiophene ring or a furan ring together with two carbon atoms bonded to X and Y. ] The organic electroluminescence device according to claim 2,
The organic light-emitting device, wherein the light-emitting layer contains at least one kind of petitene-based compound represented by the general formula 1 or the general formula 2. In the organic electroluminescent element according to claim 2 or 3,
An organic electroluminescence device, wherein the light emitting layer contains a blue phosphorescent dopant compound.   An illuminating device comprising the organic electroluminescence element according to claim 2.

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