JP2013110262A - Organic el element and organic el module and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit degradation of the characteristics even if an organic EL element is subjected to high-temperature processing of 110°C or higher.SOLUTION: An organic EL element comprises, on a support substrate 1: an anode 2; an organic EL layer 3; and a cathode 4. In the organic EL element, the organic EL layer 3 has at least a hole transport layer 302, a luminous layer 303 and an electron transport layer 305. The hole transport layer 302 is composed of a hole transport material, the luminous layer 303 is composed of a host compound and a light-emitting dopant, and the electron transport layer 305 is composed of an electron transport material. The glass transition point Tg of all of the hole transport material, the host compound and the electron transport material excepting the light-emitting dopant is 110°C or higher, and the electron transport layer 305 contains at least one kind of metal selected from alkaline metals or alkali earth metals, or a metal compound thereof.

Description

  The present invention relates to an organic EL element, an organic EL module encapsulating and protecting the organic EL element, and a method for manufacturing the same.

2. Description of the Related Art Conventionally, electroluminescence panels (EL panels) have been widely used as light sources for lighting devices and display devices.
In the EL panel, for example, in order to prevent element deterioration from the influence of heat during driving, as a means for improving the heat resistance of the element itself, there are a method of increasing the glass transition point Tg of the material and a method of suppressing mixing at the interface. Conventionally known.
In Patent Document 1, an attempt is made to suppress the influence of interfacial mixing due to heat during driving by providing a heat-resistant layer containing a material having a hole transport property and a glass transition point of 150 ° C. or higher or a glass transition point. However, this method can prevent the influence of interfacial mixing between the hole transport layer and the light emitting layer, but has a problem that it cannot prevent the influence of mixing from the electron transport layer side.

  Patent Document 2 discloses an EL panel (organic EL element) in which an anode, an organic compound layer, and a cathode are stacked on a substrate, and the stacked body is sealed with a heat dissipation plate via an adhesive layer. In particular, according to the organic EL element of Patent Document 2, a sheet-like thermosetting adhesive can be used as the adhesive layer (see paragraphs 0034 to 0036), which has been verified in Experiment 2 (paragraph). 0053-0054).

JP 2008-91570 A International Publication No. 2005/122644

When heat treatment is performed on the organic EL element, as described in paragraph 0036 of Patent Document 2, generally, the organic EL element has a heat resistant temperature of about 110 ° C., and heat treatment at a temperature exceeding this is not possible. This is considered to be a factor that deteriorates the characteristics of the organic EL element.
When the organic EL element is used for outdoor use, high durability is required, but in reality, there is a problem that the weather resistance is not sufficient due to the heat resistance problem of the organic EL element itself. In addition, even if the durability of the device itself can be maintained, when an organic EL module is used, problems such as electrode corrosion, voltage fluctuations, and luminance reduction due to the intrusion of moisture into the module can occur. I have it. In order to protect the electrode, it is useful to use a thermosetting resin having humidity resistance such as that used in a solar panel or the like, but a resin that cures at a temperature higher than 110 ° C. is the organic EL element itself. Could not be used due to heat resistance problem.
Accordingly, a main object of the present invention is an organic EL element having an excellent heat resistance including an organic compound layer, which can suppress deterioration of characteristics even when subjected to a high temperature treatment at 110 ° C. or higher. It is to provide.
Another object of the present invention is to provide an organic EL module in which the organic EL element is sealed and protected and a method for manufacturing the same.

In order to solve the above problems, according to one aspect of the present invention,
In an organic EL element in which an anode, an organic compound layer and a cathode are formed on a support substrate,
The organic compound layer has at least a hole transport layer, a light emitting layer and an electron transport layer;
The hole transport layer is composed of a hole transport material,
The light emitting layer is composed of a host compound and a light emitting dopant,
The electron transport layer is composed of an electron transport material;
All the glass transition points Tg of the hole transport material, the host compound and the electron transport material excluding the light emitting dopant are 110 ° C. or more, and the electron transport layer is selected from alkali metals or alkaline earth metals There is provided an organic EL device comprising at least one kind of metal or a metal compound thereof.

According to another aspect of the invention,
The organic EL element;
A sealing member for sealing the organic EL element with a part of the anode and the cathode exposed;
A protective member for protecting the sealing member and a part of the anode and the cathode exposed from the sealing member, and the protective member made of a thermosetting resin having a crosslinking temperature of 110 ° C. or higher;
An organic EL module is provided.

According to another aspect of the invention,
Forming the organic EL element;
Sealing the organic EL element with a portion of the anode and cathode exposed;
A protective member made of a thermosetting resin having a crosslinking temperature of 110 ° C. or higher, covering the organic EL element sealing body and part of the anode and cathode exposed therefrom, and overlapping portions of the protective member at 110 ° C. or higher A process of thermocompression bonding at a temperature of
A method for producing an organic EL module is provided.

  According to the present invention, deterioration of characteristics can be suppressed even when subjected to high temperature treatment at 110 ° C. or higher.

It is sectional drawing which shows schematic structure of an organic EL module. It is a top view which shows the manufacturing method of an organic electroluminescent module roughly.

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

<< Organic EL module (100) >>
As shown in FIG. 1, the organic EL module 100 has a support substrate 1 for supporting electrodes and organic compound layers.
An anode 2, an organic compound layer 3, and a cathode 4 are formed in this order on the support substrate 1, and the organic compound layer 3 is formed between the anode 2 and the cathode 4. The organic compound layer 3 includes, for example, a hole injection layer 301, a hole transport layer 302, a light emitting layer 303, a hole blocking layer 304, an electron transport layer 305, and the like.
The laminate of the anode 2, the organic compound layer 3, and the cathode 4 is sealed (covered) with a sealing member 5. In the organic EL module 100, the sealing member 5 is made of a sealing resin.
The laminated body of the support substrate 1, the anode, the organic compound layer 3, and the cathode 4 is covered and protected by two protective members 10. The protective member 10 is mainly composed of a protective substrate 11 and an adhesive layer 12. The side edge portions of the protective members 10 are heat-bonded with the adhesive layers 12 of the protective members 10 facing each other.
Extraction electrodes 20 and 21 are connected to the anode 2 and the cathode 4, and the extraction electrodes 20 and 21 extend through the sealing member 5 and the adhesive layer 12 to the outside of the organic EL module 100. From such a configuration, the protective member 10 covers and protects the sealing member 5 and part of the anode 2 and the cathode 4 (extraction electrodes 20 and 21) of the organic EL element.
Note that the organic EL element according to the present embodiment is basically composed of a member obtained by removing the protective member 10 from the organic EL module 100 (or a member obtained by removing the sealing member 5 and the protective member 10).

<< Layer structure of organic EL element >>
Next, although the preferable specific example of the layer structure of the 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

The light emitting layer includes a fluorescent light emitting layer and a phosphorescent light emitting layer.
The fluorescent light-emitting layer is a layer that mainly emits light from an excited singlet, and preferably has a fluorescent dopant and a fluorescent host.
In the present invention, the fluorescent dopant preferably emits blue light, is dissolved in a solvent such as 2-methyl THF, and the emission maximum wavelength in a dilute solution is preferably 400 to 500 nm, and preferably 420 to 480 nm. More preferred.
The fluorescent light-emitting layer of the present invention has at least one layer structure, and may be a single layer or a plurality of layers.

On the other hand, the phosphorescent light emitting layer is a layer that mainly emits light from an excited triplet, and preferably has a phosphorescent dopant and a phosphorescent host.
In the present invention, the phosphorescent dopant may be of any emission color, but when white emission is intended as the emission color of the organic EL element, it is a yellow emission color or a green and red emission color. And is preferably combined with a blue fluorescent light emitting layer.
The phosphorescent light emitting layer of the present invention has a layer structure of at least one layer, and may be a single layer or a plurality of layers, and it is preferable to provide a plurality of phosphorescent light emitting layers having different emission colors.

<< Light emitting layer (phosphorescent light emitting layer, fluorescent light emitting layer (303)) >>
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 be the interface between the light emitting layer and the adjacent layer. The structure of the light emitting layer according to the present invention is not particularly limited as long as it satisfies the requirements defined in the present invention.

  The total thickness of the light emitting layer is not particularly limited, but it prevents the uniformity of the film to be formed, 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. From the viewpoint, it is preferable to adjust to a range of 5 nm to 200 nm, and more preferably to a range of 20 nm to 150 nm. Moreover, in the structure prescribed | regulated by the structure of this invention, it is preferable to adjust as the film thickness of each light emitting layer in the range of 5 nm-200 nm, More preferably, by adjusting in the range of 3 nm or more and 150 nm or less. is there.

The light emitting layer according to the present embodiment may be configured with either a fluorescent light emitting layer or a phosphorescent light emitting layer, or may be configured with both.
The fluorescent light emitting layer contains a fluorescent light emitting dopant and a host compound. The content ratio of the fluorescent dopant is 0.01 to 20% by volume, preferably 0.1 to 10% by volume.
The phosphorescent layer also contains a phosphorescent dopant and a host compound. The content ratio of the phosphorescent dopant is 0.01 to 40% by volume, preferably 0.1 to 20% by volume.

  As a method for forming the light emitting layer, a light emitting dopant or a host compound described later can be used, for example, a vacuum deposition method, a spin coating method, a casting method, an LB method (Langmuir-Blodget method), an ink jet method, a spray method, a printing method, The film can be formed by a known thin film forming method such as a slot type coater method.

  The number of layers constituting the light emitting layer is not particularly limited as long as it has a configuration satisfying the requirements defined in the present invention, and the number of stacked layers can be arbitrarily set.

  The phosphorescent light emitting or fluorescent light emitting dopant contained in each light emitting layer may be contained in the light emitting layer at a uniform concentration in the film thickness direction, but has a concentration distribution. Also good.

(1) Host Compound Next, a host compound (also referred to as a light emitting host compound) contained in the light emitting layer will be described.
As a host compound, a host compound may be used independently or may be used in combination of multiple types.

  The phosphorescent host compound contained in the phosphorescent layer of the organic EL device of the present invention is preferably a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1. Preferably, it is a compound having a phosphorescence quantum yield of less than 0.01.

  The phosphorescent host compound used in the present invention is not particularly limited in terms of structure, but is typically a carbazole derivative, triarylamine derivative, aromatic borane derivative, nitrogen-containing heterocyclic compound, thiophene derivative, furan derivative. A compound having a basic skeleton such as an oligoarylene compound, or a carboline derivative or a diazacarbazole derivative (herein, a diazacarbazole derivative is at least one carbon atom of a hydrocarbon ring constituting a carboline ring of a carboline derivative) Represents the one substituted with a nitrogen atom).

  As the phosphorescent host compound used in the light emitting layer according to the present invention, a compound represented by the following general formula (a) is preferable.

  In the general formula (a), X represents NR ′, O, S, CR′R ″ or SiR′R ″, R ′ and R ″ each represent a hydrogen atom or a substituent. Ar represents an aromatic ring. N represents an integer of 0 to 8.

  In X in the general formula (a), the substituents represented by R ′ and R ″ are alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group). 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 (aromatic carbocyclic group, aryl group, etc.) For example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, an Ryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc., aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group) Group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) ), A phthalazinyl group, etc.), a heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), an alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, Hexyloxy group, oct Ruoxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group). Propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (for example, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (Eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, etc.) Xycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, Dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), 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 (For example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethyl group) Carbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino 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, A cyclohexylaminocarbonyl group, an octylaminocarbonyl group, a 2-ethylhexylaminocarbonyl group, a dodecylaminocarbonyl group, a phenylaminocarbonyl group, a naphthylaminocarbonyl group, a 2-pyridylaminocarbonyl group, etc.), a ureido group (for example, a 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, phenylsulfinyl group, naphthylsulfinyl group, Dilsulfinyl group etc.), alkylsulfonyl group (eg methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group etc.), arylsulfonyl group or heteroarylsulfonyl group (eg , 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, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, Tafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono Groups and the like.

  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.

  In the general formula (a), X is preferably NR ′ or O, and R ′ is particularly preferably an aromatic hydrocarbon group or an aromatic heterocyclic group.

  In the general formula (a), examples of the aromatic ring represented by Ar include an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Further, the aromatic ring may be a single ring or a condensed ring, and may be unsubstituted or may have a substituent as described later.

  In the general formula (a), examples of the aromatic hydrocarbon ring represented by Ar include a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, Examples include a pyranthrene ring and anthraanthrene ring. These rings may further have a substituent.

  In the general formula (a), examples of the aromatic heterocycle represented by Ar include a furan ring, a dibenzofuran ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. , Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indazole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline Ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (showing a ring in which one of the carbon atoms of the hydrocarbon ring constituting the carboline ring is further substituted with a nitrogen atom), etc. Can be mentioned. These rings may further have a substituent.

  Among these, in the general formula (a), the aromatic ring represented by Ar is preferably a carbazole ring, a carboline ring, a dibenzofuran ring, or a benzene ring, and particularly preferably used is a carbazole ring, A carboline ring or a benzene ring. Among these, a benzene ring having a substituent is preferable, and a benzene ring having a carbazolyl group is particularly preferable.

  In the general formula (a), the aromatic ring represented by Ar is preferably a condensed ring having three or more rings, as shown below, and is an aromatic hydrocarbon in which three or more rings are condensed. Specific examples of the condensed ring include naphthacene ring, anthracene ring, tetracene ring, pentacene ring, hexacene ring, phenanthrene ring, pyrene ring, benzopyrene ring, benzoazulene ring, chrysene ring, benzochrysene ring, acenaphthene ring, acenaphthylene ring, Triphenylene ring, coronene ring, benzocoronene ring, hexabenzocoronene ring, fluorene ring, benzofluorene ring, fluoranthene ring, perylene ring, naphthoperylene ring, pentabenzoperylene ring, benzoperylene ring, pentaphen ring, picene ring, pyranthrene ring, coronene ring , Naphthocoronene ring, Ovalene ring, Anse Antoren ring and the like. In addition, these rings may further have a substituent.

  Specific examples of the aromatic heterocycle condensed with three or more rings include an acridine ring, a benzoquinoline ring, a carbazole ring, a carboline ring, a phenazine ring, a phenanthridine ring, a phenanthroline ring, a carboline ring, a cyclazine ring, Kindin ring, tepenidine ring, quinindrin ring, triphenodithiazine ring, triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, diazacarbazole ring (any one of the carbon atoms constituting the carboline ring is a nitrogen atom Phenanthroline ring, dibenzofuran ring, dibenzothiophene ring, naphthofuran ring, naphthothiophene ring, benzodifuran ring, benzodithiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, A Tiger thiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, such as thio fan Tren ring (naphthaldehyde thiophene ring), and the like. In addition, these rings may further have a substituent.

  Here, in the general formula (a), the substituents that the aromatic ring represented by Ar may have are the same as the substituents represented by R ′ and R ″.

  In the general formula (a), n represents an integer of 0 to 8, preferably 0 to 2, and particularly preferably 1 or 2 when X is O or S.

  Specific examples of the light-emitting host compound represented by the general formula (a) are shown below, but are not limited thereto.

  The phosphorescent host compound used in the present invention may be a low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). But it is good.

  As the phosphorescent host compound, a compound having a glass transition temperature Tg of 110 ° C. or higher is used, and a compound that has a hole transporting ability and an electron transporting ability and that can prevent the emission of light from being increased in wavelength is preferable.

  As specific examples of conventionally known host compounds, compounds described in the following documents are suitable. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. 2002-302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  In the present invention, in the case of having a plurality of light emitting layers, the host compound may be different for each light emitting layer, but the same compound is preferable because excellent driving life characteristics are obtained.

  Further, the phosphorescent host compound preferably has a lowest excited triplet energy (T1) larger than 2.2 eV because higher luminous efficiency can be obtained. The lowest excited triplet energy as used in the present invention refers to the peak energy of the emission band corresponding to the transition between the lowest vibrational bands of the phosphorescence emission spectrum observed at a liquid nitrogen temperature after dissolving the host compound in a solvent.

  Here, the glass transition point (Tg) is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

  In the organic EL device of the present invention, since the host material is responsible for carrier transport, a material having carrier transport capability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance of hole and electron injection / transport, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

  In addition, the said phosphorescent host compound can be used suitably also as a host compound with respect to a fluorescence emission dopant.

(2) Luminescent dopant Next, the luminescent dopant according to the present invention will be described.

(2.1) Fluorescent light emitting dopant (also called fluorescent dopant, fluorescent light emitter, etc.)
Examples of the fluorescent dopant used as the luminescent material according to the present invention include a coumarin dye, a pyran dye, a cyanine dye, a croconium dye, a squalium dye, an oxobenzanthracene dye, a fluorescein dye, a rhodamine dye, Examples include pyrylium dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Conventionally known dopants can also be used in the present invention. For example, International Publication No. 00/70655 pamphlet, JP-A Nos. 2002-280178, 2001-181616, 2002-280179, 2001 181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178, 2002-302671, 2001-345183, 2002. No. 324679, International Publication No. 02/15645, JP 2002-332291 A, 2002-50484, 2002-332292, 2002-83684, JP 2002-540572, JP 2 No. 02-117978, No. 2002-338588, No. 2002-170684, No. 2002-352960, Pamphlet of International Publication No. 01/93642, JP 2002-50483, No. 2002-1000047. No. 2002-173684, No. 2002-359082, No. 2002-17584, No. 2002-363552, No. 2002-184582, No. 2003-7469, No. 2002-525808. JP-A 2003-7471, JP-T 2002-525833, JP-A 2003-31366, JP-A 2002-226495, JP-A 2002-234894, JP-A 2002-2335076, JP-A 2002-24175 Gazette, 2001-319779, 2001-319780, 2002-62824, 2002-1000047, 2002-203679, 2002-343572, 2002-203678. A gazette etc. are mentioned.

(2.2) Phosphorescent dopant The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed, specifically, a compound that emits phosphorescence at room temperature (25 ° C.). The phosphorescence quantum yield is defined as a compound of 0.01 or more at 25 ° C., but the preferred phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured, for example, by the method described in Spectroscopic 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 phosphorescent emitter according to the present invention has the phosphorescence quantum yield (0.01 or more) in any solvent. It only has to be achieved.

There are two types of light emission principle of the phosphorescent dopant.
One type is that a carrier (electron, hole) is combined on the host compound to which the carrier is transported, and an excited state of the host compound is generated. It is an energy transfer type that obtains light emission from.
The other type is a carrier trap type in which the phosphorescent light emitting dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent light emitting dopant, and light emission from the phosphorescent light emitting dopant is obtained.
In any case, the excited state energy of the phosphorescent dopant is preferably lower than the excited state energy of the host compound in order to obtain high light emission efficiency.

  The phosphorescent light emitting dopant can be appropriately selected from known materials used for the light emitting layer of the organic EL device.

  The phosphorescent dopant according to the present invention is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex system). Compound) and rare earth complexes, and most preferred is an iridium compound.

  Specific examples of compounds that can be used in the present invention are shown below. These compounds are described in, for example, Inorg. Chem. 40, 1704-1711, and the like.

<< Injection layer: electron injection layer, hole injection layer (301) >>
The injection layer can be provided as necessary, and may exist between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer.

  An injection layer is a layer provided between an electrode and an organic layer in order to lower drive voltage and improve light emission luminance. For example, “Organic EL element and its forefront of industrialization (November 30, 1998, NTS Corporation) Issue) ”, Chapter 2, Chapter 2,“ Electrode Materials ”(pages 123-166), which is described in detail, and has a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer). .

  Details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, and the like. As a specific example, copper phthalocyanine Phthalocyanine buffer layer typified by (1), oxide buffer layer typified by vanadium oxide, amorphous carbon buffer layer, polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene, and the like. Moreover, it is also preferable to use the material described in Japanese translations of PCT publication No. 2003-519432 gazette.

  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, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. .

  The buffer layer (injection layer) is preferably a very thin film, and although it depends on the material used, the film thickness is preferably in the range of 0.1 nm to 5 μm.

<< Blocking layer: Hole blocking layer (304), electron blocking layer >>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (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 that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer as needed.

  The hole blocking layer provided in the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  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 while having a very small ability to transport electrons, and transporting electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved. 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 the electron transport layer according to the present invention is preferably 3 nm to 100 nm, and more preferably 5 nm to 30 nm.

<< Hole Transport Layer (302) >>
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also 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 one 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 polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is further preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

  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, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. , 95, 5773 (2004), JP-A-11-251067, J. MoI. Huang et. al. It is also possible to use a hole transport material that has a so-called p-type semiconducting property as described in the literature (Applied Physics Letters 80 (2002), p. 139), JP 2003-519432 A. it can.
In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained. Among these materials, materials having a glass transition temperature Tg of 110 ° C. or higher are used.

  For the hole transport layer, the hole transport material may be selected from, for example, vacuum deposition method, spin coating method, casting method, LB method (Langmuir-Blodget method), ink jet method, spray method, printing method, slot type coater method, etc. The film can be formed by a known thin film forming method. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

<< Electron Transport Layer (305) >>
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.

  Conventionally, when a single electron transport layer and a plurality of layers are used, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transmitting the generated electrons to the light-emitting layer, any material selected from conventionally known compounds can be selected and used. For example, nitro-substituted fluorene derivatives, diphenylquinone Derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane 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, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting 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 similarly to the hole injection layer and the hole transport layer, inorganic such as n-type-Si and n-type-SiC can be used. A semiconductor can also be used as an electron transport material.
In particular, in this embodiment, a material having a glass transition temperature Tg of 110 ° C. or higher is used as the electron transport material.

  For the electron transport layer, the above-mentioned electron transport material may be a known material such as a vacuum deposition method, a spin coat method, a cast method, an LB method (Langmuir-Blodget method), an ink jet method, a spray method, a printing method, or a slot type coater method. The film can be formed by a thin film forming 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 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  In addition, an electron transport material that has n-type semiconductor properties doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport material having such n-type semiconductor properties because an element with lower power consumption can be produced.

The electron transport layer according to the present embodiment is mainly composed of a compound having a phenylpyridine structure, and further contains one or more kinds of metals selected from alkali metals or alkaline earth metals or metal compounds thereof. Has been.
The “metal compound” includes organometallic complexes, metal-organic salts, metal-inorganic salts, oxides, and halides.
Particularly useful are Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, and these organic or inorganic compounds. In particular, it is preferable to use a halide of an alkali metal or alkaline earth metal.
The content ratio of the metal and the metal compound in the constituent material of the electron transport layer is 0.01 to 45% by volume, preferably 0.1 to 25% by volume.

  The compound having a phenylpyridine structure is preferably represented by the general formula (1)

In the general formula (1), “Ar ₁ ” represents an n-valent aryl group, “R” and “R ′” each represent a hydrogen atom or a substituent, and “n” represents an integer of 1 or more and 6 or less. . When a plurality of R and R ′ are present, adjacent substituents may be condensed with each other to form a ring.

In the general formula (1), when R and R ′ represent a substituent, specific examples of these substituents include an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trimethyl group). Fluoromethyl group, perfluoropropyl group, perfluoro-n-butyl group, perfluoro-t-butyl group, t-butyl group, benzyl group, etc.) and alicyclic hydrocarbon residues such as cycloalkyl group ( A cyclopentyl group, a cyclohexyl group, etc.) and a cycloalkenyl group (for example, a cyclohexenyl group, a cyclopentenyl group), and the like, an aralkyl group (for example, a benzyl group, a 2-phenethyl group, etc.), an aryl group (for example, a phenyl group, a naphthyl group, p-tolyl group, p-chlorophenyl group, fluorenyl group, etc.), alkoxy group (for example, ethoxy group, isopropo group) Xy group, butoxy group etc.), aryloxy group (eg phenoxy group etc.), alkylthio group (methylthio, ethylthio, isopropylthio group etc.), arylthio group (eg phenylthio group, naphthylthio group, p-tolylthio group, p-chlorophenylthio) Group), hydroxyl group, amino group (dimethylamino group, diarylamino group), alkenyl group (for example, allyl group, 1-ethenyl group, 1-propenyl group, 1-butenyl group, 1-octadecenyl group, etc.), halogen atom ( Fluorine atom, chlorine atom, bromine atom, iodine atom, etc.).
These groups may be further substituted, and examples of the substituent include a halogen atom, hydroxyl group, nitro group, cyano group, carboxyl group, sulfo group, alkyl group, aryl group, alkoxy group, aryloxy group, alkylthio group. Group, arylthio group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, acyloxy group, amino group, carbonamido group, sulfonamido group, carbamoyl group, sulfamoyl group, ureido group, alkoxycarbonyl An amino group, a sulfamoylamino group, etc. are mentioned. Preferable examples of R and R ′ include a hydrogen atom, an alkyl group, and an aryl group, and a hydrogen atom is more preferable.

In the general formula (1), the benzene ring and the pyridine ring may be bonded at any position, but preferably bonded to the benzene ring at the 2-position of the pyridine, and the benzene ring side is connected to Ar ₁ . It is preferable that it is bonded to the pyridine ring at the bonded ortho position. In addition, a structure in which a benzene ring and a pyridine ring are condensed via R and R ′ may be employed.

In the general formula (1), the aryl group represented by Ar ₁ includes an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a triphenylene group, a biphenyl group, and a terphenyl group, a pyridyl group, a pyrimidyl group, a triazinyl group, and a thienyl group. An aromatic heterocyclic group such as a furyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a quinolyl group, an isoquinolyl group, an azacarbazolyl group, and the aryl group represented by Ar ₁ has a substituent. Further, it may have a structure in which a plurality of aryl groups are linked. Examples of the aryl group represented by Ar ₁ include a phenyl group, a dibenzofuranyl group, a carbazolyl group, a dibenzothienyl group, and azacarbazolyl.

In the general formula (1), n represents an integer of 1 to 6, and is bonded to the phenylpyridine structure through n bonds from the aryl group.
n is preferably 2 or 3, and specific examples of the structure of Ar ₁ include those listed below or combinations thereof (Ar ₂ represents an aryl group, and the benzene ring of the general formula (1) at the position of * Combined with).

  Although the specific example of the compound which concerns on General formula (1) is shown, it is not limited to these.

<< Support substrate (1) >>
The support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) applied to the organic EL element of the present invention is not particularly limited in the type of glass, plastic, etc., and may be transparent. It may be 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 organic EL element.

Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned. An inorganic or organic film or a hybrid film of both may be formed on the surface of the resin film, and the water vapor permeability measured by a method according to JIS K 7129-1992 is 0.01 g / (m ² · 24 h · atm) or less, and the oxygen permeability measured by a method according to JIS K 7126-1992 is preferably 10 ⁻³ g / (m ² · 24 h) or less. The water vapor permeability is preferably a high barrier film of 10 ⁻³ g / (m ² · 24 h) or less, and both the water vapor permeability and the oxygen permeability are 10 ⁻⁵ g / (m ² · 24h) or less is more preferable.

  As a material for forming the barrier film, any material may be used as long as it 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 can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. 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, the sputtering method, the reactive sputtering method, the molecular beam epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, the 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, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is also preferable.

  Examples of the opaque support substrate include metal plates / films such as aluminum and stainless steel, opaque resin substrates, ceramic substrates, and the like.

<< Anode (2) >>
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such an electrode substance include conductive transparent materials such as metals such as Au, 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, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method. ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. 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 selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

<< Cathode (4) >>
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 one of the anode or the cathode of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.

  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.

<< Sealing (Sealing member 5) >>
Examples of the sealing means used for sealing the organic EL element of the present invention include a method of covering with a sealing resin, a method of bonding a sealing member, an electrode and a support substrate with an adhesive. it can.

The sealing member should just be arrange | positioned so that the display area of an organic EL element may be covered, and has sealed the organic EL element in the state which exposed a part (extraction electrode) of the anode and the cathode.
The sealing member may have a concave plate shape or a flat plate shape, and the presence or absence of transparency and electrical insulation is not particularly limited.

  Specifically, examples of the sealing member include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. 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 organic EL element can be thinned. Furthermore, the polymer film preferably has an oxygen permeability of 10 ⁻³ g / (m ² · 24 h) or less and a water vapor permeability of 10 ⁻³ g / (m ² · 24 h) or less. Moreover, it is more preferable that both the water vapor permeability and the oxygen permeability are 10 ⁻⁵ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used. Specific examples of the adhesive include photocuring and thermosetting adhesives having a reactive vinyl group of acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylate. be able to. Moreover, the 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.

  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 it like screen printing.

  In addition, it is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. it can. 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 the element such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like is used. it can. Furthermore, 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 organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil is injected in the gas phase and the liquid phase. Is preferred. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg, calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, etc.), perchloric acids (eg, barium perchlorate) , Magnesium perchlorate, etc.), and anhydrous salts are preferably used in sulfates, metal halides and perchloric acids.

<< Protective member (10) >>
A protective member is provided on the outer side of the sealing film or sealing film facing the support substrate of the organic EL element for the purpose of protecting the extraction electrode of the organic EL element.
In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, so it is preferable to provide such a protective member.
The protective member is mainly composed of a protective substrate and an adhesive layer, and the adhesive layer is formed on the protective substrate. The protective member has an adhesive layer adhered to the sealing member, and covers and protects the sealing member and a part of the anode and the cathode (extraction electrode) of the organic EL element exposed therefrom.
As a protective substrate, it has excellent mechanical or chemical strength, specifically, various fastnesses such as weather resistance, heat resistance, water resistance, light resistance, wind pressure resistance, yield resistance, chemical resistance, puncture resistance, etc. An excellent resin sheet is used. Examples of such resin sheets include polyethylene resins, polypropylene resins, cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, polyvinyl chloride resins, fluorine Resins, poly (meth) acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate, polyamide resins such as various nylons, polyimide resins, polyamideimide resins, polyaryls Various resin sheets such as phthalate resin, silicone resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin, etc. It is possible to use. As the protective substrate, glass can be used instead of the resin sheet.
As the resin constituting the adhesive layer, a thermosetting resin having a heating temperature of 110 ° C. or higher in the curing process is used, and a resin that exhibits flexibility when processed into a sheet shape is preferable. Examples of such resins include EVA (ethylene-vinyl acetate copolymer) based resins, PVB (polyvinyl butyral) based resins, silicone based resins, polyethylene based resins, and the like. These resins can be used alone or in combination of two or more depending on the required performance.

<< Method for Manufacturing Organic EL Module >>
First, as an example of a method for producing an organic EL element, a method for producing an organic EL element comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.

  As shown in FIG. 2 (a), first, a desired electrode material, for example, a thin film made of an anode material is deposited on an appropriate support substrate 1 so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm. The anode 2 is produced by forming the film by a method such as sputtering.

Next, an organic compound layer 3 including a hole injection layer 301, a hole transport layer 302, a light emitting layer 303, a hole blocking layer 304, and an electron transport layer 305, which are organic EL element materials, is formed thereon.
In such a case, a material having a glass transition temperature of 110 ° C. or higher is selected for at least the hole transport material of the hole transport layer 302, the host compound of the light emitting layer 303, and the electron transport material of the electron transport layer 304.
As a method for forming the organic compound layer 3, as described above, the vapor deposition method, the wet process (spin coating method, casting method, ink jet method, printing method, LB method (Langmuir-Blodgett method), spray method, printing method, slot type However, the vacuum deposition method, the spin coating method, the ink jet method, the printing method, and the slot type coater method are particularly preferable from the viewpoints that a homogeneous film can be easily obtained and that pinholes are hardly formed.

Further, a different forming method (film forming method) may be applied for each layer.
When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 ° C. to 450 ° C., a vacuum degree of 10 ⁻⁶ Pa to 10 ⁻² Pa, and a vapor deposition rate of 0. It is desirable to select appropriately within the range of 01 nm / second to 50 nm / second, substrate temperature −50 ° C. to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 nm to 200 nm.

  Thereafter, as shown in FIG. 2 (b), a thin film made of a cathode material is deposited on the organic compound layer 3 to a thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm, for example, by vapor deposition or sputtering. By forming the cathode 4 and providing the cathode 4, a desired organic EL element can be obtained.

  The organic EL element is preferably manufactured from the hole injection layer 301 to the cathode 4 consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  Alternatively, the cathode 4, the electron transport layer 305, the hole blocking layer 304, the light emitting layer 303, the hole transport layer 302, the hole injection layer 301, and the anode 2 can be formed in the reverse order.

Thereafter, as shown in FIG. 2C, the extraction electrodes 20 and 21 are connected to the anode 2 and the cathode 4 of the organic EL element, respectively, and the organic EL element is connected to a part of the anode 2 and the cathode 4 (the extraction electrode 20, 21) is exposed and sealed with a sealing member 5 (sealing resin).
Thereafter, as shown in FIG. 2 (d), the organic EL element sealing body and the anode 2 and part of the cathode 4 (extraction electrodes 20, 21) exposed therefrom are covered with the protective member 10. Then, the overlapping portion of the protective member 10 is heat-bonded at a temperature of 110 ° C. or higher. In such a case, two protective members 10 may be overlapped to cover an organic EL element sealing body and the side edges thereof may be heat-pressed together, or one protective member 10 may be folded to form an organic EL element. The side edges (particularly the open ends) may be thermocompression-bonded.
By the above process, the organic EL module 100 in which the organic EL element is sealed and protected is manufactured.
The organic EL module 100 can also be applied to a large panel manufactured by arranging a plurality of organic EL elements. In the case of large panels that are used outdoors as advertisements or signs, particularly high durability is required, so the exposed portions of the electrodes (take-out electrodes 20, 21) after arranging a plurality of organic EL elements are arranged, It is particularly preferable to protect using the protective member 10.

<Display device>
A display device to which the organic EL element or the organic EL module of the present invention is applied will be described.
The organic EL element or organic EL module of the present invention is used for a multicolor or white display device.
In the case of a multicolor or white display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, slot coater, or the like. When patterning is performed only on the light-emitting layer, the method is not limited, but a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.

In the production of the organic EL element, it is possible to produce the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, and the anode in this order by reversing the production order.
When a DC voltage is applied to the multicolor or white display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode.

Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs.
Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

《Lighting device》
A lighting device to which the organic EL element or the organic EL module of the present invention is applied will be described.
The organic EL element or the organic EL module of the present invention may be used as a kind of lamp for illumination or an exposure light source, or a projection device that projects an image, or directly recognizes a still image or a moving image. It may be used as a type of display device (display).
The driving method when used as a display device for moving image reproduction may be either a simple matrix (passive matrix) method or an active matrix method.

  In the white organic EL element or organic EL module used in 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. When patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire element layer may be patterned.

  The light emitting dopant used in the light emitting layer is not particularly limited. For example, in the case of a backlight in a liquid crystal display element, the platinum complex according to the present invention is adapted so as to conform to the wavelength range corresponding to the CF (color filter) characteristics. Any one of known light-emitting dopants may be selected and combined, or combined with the light extraction and / or light collecting sheet according to the present invention to be whitened.

  As described above, the white organic EL element or the organic EL module of the present invention is combined with a CF (color filter), and an element and a driving transistor circuit are arranged in accordance with a CF (color filter) pattern. Using white light extracted from the luminescence element as a backlight, blue light, green light, and red light are obtained through a blue filter, green filter, and red filter, thereby producing a full-color organic electroluminescence display with a low driving voltage and a long life. It is possible and preferable.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

<< Production of sample (organic EL element) >>
(1) Formation of anode and cleaning of supporting substrate First, as an anode, ITO is formed on a glass substrate having a length and width of 30 mm × 30 mm and a thickness of 0.7 mm under a condition of a thickness of 110 nm by patterning by sputtering. Then, an anode (anode) made of an ITO layer was formed.
Next, the transparent support substrate provided with the ITO layer was subjected to ultrasonic cleaning with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

(2) Production of Samples 101 to 120 (2.1) Production of Sample 101 Poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, glass transition point ( Tg) = 190 ° C., Bayer, Baytron P Al 4083) diluted to 70% with pure water was formed into a film by spin coating at 3000 rpm for 30 seconds, and then dried at 130 ° C. for 1 hour. A hole injection layer having a thickness of 30 nm was provided.

After providing the hole injection layer, the transparent support substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus.
Each of the deposition crucibles in the vacuum deposition apparatus was filled with the constituent material of each layer in an optimum amount for device fabrication. The evaporation crucible used was made of a resistance heating material made of molybdenum or tungsten.

Subsequently, after reducing the pressure to 1 × 10 ⁻⁴ Pa, HT-1 (glass transition point (Tg) = 148 ° C.) was deposited to a thickness of 70 nm to form a hole transport layer.

  Subsequently, it vapor-deposited so that the compound 2 (Tg = 189 degreeC) might be 95%, and the compound 3 might be 5%, and formed the 10-nm-thick fluorescence light emitting layer.

  Subsequently, it vapor-deposited so that H-1 (Tg = 129 degreeC) might be 86%, the compound 5 might be 12 mass%, and the compound 6 might be 2 mass%, and the 5-nm-thick phosphorescence emitting layer 1 was formed.

Subsequently, it vapor-deposited so that H-1 (Tg = 129 degreeC) might be 88 mass%, and the compound 5 might be 12 mass%, and the phosphorescence layer 2 of thickness 10nm was formed.
Further, Compound E-1 (Tg = 147 ° C.) and potassium fluoride were co-evaporated to a concentration of 50% by mass to form an electron transport layer having a thickness of 40 nm.
Next, aluminum was deposited to 110 nm to form a cathode, and the non-light emitting surface was covered with a glass case and sealed to obtain an organic EL element (sample 101).

(2.2) Production of Sample 102 In production of the sample 101, after the phosphorescent light emitting layer 2 was formed, H-1 (Tg = 129 ° C.) was vapor-deposited to form a 10 nm thick hole blocking layer.
Others were manufactured in the same manner as Sample 101.

(2.3) Preparation of Samples 103 and 104 In the preparation of Sample 102, the hole transport material was changed to HT-2 (Tg = 110 ° C.) and HT-3 (Tg = 140 ° C.).
Other than that, Samples 103 and 104 were manufactured in the same manner as Sample 102.

(2.4) Preparation of Samples 105 to 107 In preparation of Sample 102, the phosphorescent host materials were H-2 (Tg = 114 ° C.), H-3 (Tg = 131 ° C.), H-4 (Tg = 141 ° C.). ) Respectively.
Otherwise, Samples 105 to 107 were prepared in the same manner as Sample 102.

(2.5) Preparation of Samples 108 and 109 In the preparation of Sample 102, the constituent material of the electron transport layer was changed to E-2 and E-3.
Other than that, Samples 108 and 109 were manufactured in the same manner as Sample 102.

(2.6) Production of Sample 110 In production of the sample 102, the constituent material of the electron transport layer was changed to H-4, and potassium fluoride was changed to lithium fluoride.
Other than that, Sample 110 was manufactured in the same manner as Sample 102.

(2.7) Preparation of Sample 111 In preparation of Sample 102, potassium fluoride was deposited as an electron injection layer by 2 nm after the electron transport layer was formed.
Otherwise, Sample 111 was obtained in the same manner as Sample 102.

(2.8) Production of Sample 112 In production of the sample 108, 1 nm of potassium fluoride was deposited as an electron injection layer after the production of the electron transport layer.
Otherwise, Sample 112 was obtained in the same manner as Sample 108.

(2.9) Production of Sample 113 In production of the sample 108, an electron transport layer was formed after the phosphorescent light emitting layer 2 was formed, and potassium fluoride was deposited as an electron injection layer after the formation of the electron transport layer by 2 nm.
Otherwise, Sample 112 was obtained in the same manner as Sample 108.

(2.10) Preparation of Sample 114 In preparation of Sample 102, lithium fluoride was co-evaporated on the electron transport layer, and then 1 nm of lithium fluoride was formed as the electron injection layer.
Other than that, Sample 114 was obtained in the same manner as Sample 102.

(2.11) Preparation of Sample 115 In preparation of Sample 110, 1 nm of lithium fluoride was formed in the electron injection layer.
Otherwise, Sample 115 was obtained in the same manner as Sample 110.

(2.12) Preparation of Sample 116 In the preparation of Sample 102, the constituent material of the electron transport layer was changed to E-4 (Tg = 104 ° C.).
Other than that, Sample 116 was manufactured in the same manner as Sample 102.

(2.13) Preparation of Sample 117 In preparation of Sample 102, the hole transport material was changed to α-NPD (Tg = 95 ° C.).
Other than that, Sample 117 was manufactured in the same manner as Sample 102.

(2.14) Production of Sample 118 In production of the sample 102, the host of the phosphorescent light emitting layers 1 and 2 was changed to H-5 (Tg = 102 ° C.).
Other than that, Sample 118 was manufactured in the same manner as Sample 102.

(2.15) Production of Sample 119 In the production of Sample 102, the electron transport material was changed to only E-1, and 2 nm of potassium fluoride was formed as an electron injection layer.
Otherwise, Sample 119 was made in the same manner as Sample 102.

(2.16) Preparation of Sample 120 In preparation of Sample 119, the electron transport material was changed to Balq (Tg = 99 ° C.), and lithium fluoride was formed to 1 nm as an electron injection layer.
Otherwise, sample 120 was made in the same manner as sample 119.

<Evaluation of sample>
(1) Calculation of external extraction light emission efficiency The external extraction light emission quantum efficiency at an energization amount of 5 mA / cm ² was obtained.
A spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing Co., Ltd.) was used for measuring the external extraction luminescence quantum efficiency. By measuring the front luminance and luminance accuracy dependence of each organic EL element, the amount of light emitted from the front surface of the substrate to the outside was measured, and the external emission luminescence quantum efficiency was calculated.
The calculation results are shown in Tables 3 and 4.
In Tables 3 and 4, the value of the luminous efficiency is expressed as a relative value when the sample 101 is 100.

(2) Performance evaluation accompanying heat treatment Each sample was heated for 1 hour under the heating conditions (100 ° C., 110 ° C., 150 ° C.) shown in Table 3 and Table 4, and the performance before and after heating (driving voltage and emission luminance) ) Was calculated.
A spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing Co., Ltd.) was used for measurement of drive voltage and emission luminance in the same manner as described above.
The evaluation results are shown in Table 3 and Table 4.
In Tables 3 and 4, “voltage fluctuation” indicates a relative value when the driving voltage before heating is 100. “Luminance change rate” indicates the remaining luminance rate (%) before and after heating.
In addition, the heating conditions set temperature and time on the assumption that the organic EL element is subjected to thermocompression bonding with a protective member.

(3) Summary As shown in Table 3 and Table 4, when Samples 101 to 115 and Samples 116 to 120 are compared, Samples 101 to 115 are improved in luminous efficiency or reduced in luminous efficiency and heated. The fluctuation in performance is suppressed before and after, and the effect is particularly prominent under heating temperature conditions of 110 ° C. or higher.
From the above, in order to suppress deterioration of the characteristics (performance) of the organic EL element with respect to a high temperature treatment of 110 ° C. or higher, a material having a glass transition point of 110 ° C. or higher is selected as the constituent material of the organic compound layer, and electron transport is performed. It can be seen that it is useful to include a certain metal compound in the layer.

<< Production of sample (organic EL module) >>
(1) Preparation of Protective Member A “protective member A” was prepared by adhering an ethylene polymer resin Nucrel (Mitsui DuPont, cross-linking temperature 100 ° C.) to a PET film.
EVA protective resin CIKcap (manufactured by C-I Kasei Co., Ltd., crosslinking temperature 150 ° C.) was adhered to the PET film to prepare “Protective Member B”.

(2) Production of Samples 101 to 120 Each of the organic EL elements 101 to 120 of Example 1 is covered with the protective members A and B, thermocompression bonded, and then cured by heating, and 2 for each of the organic EL elements 101 to 120. Organic EL modules were produced one by one.
In the protection by the protective member A, thermocompression bonding was performed at 90 ° C. for 30 minutes, and then heat curing was performed in an oven at 100 ° C. for 30 minutes.
In the protection by the protective member B, thermocompression bonding was performed at 130 ° C. for 2 minutes, and then heat curing was performed in an oven at 150 ° C. for 30 minutes.

<Evaluation of sample>
Each sample was stored for 1000 hours under a high temperature and high humidity condition of a temperature of 85 ° C. and a humidity of 85%, and the amount of change in performance (drive voltage and light emission luminance) before and after storage was calculated.
The calculation of the fluctuation amount was performed by the same method and standard as in Example 1.
The calculation results are shown in Tables 5 and 6.
At the same time, when the sample after being stored for 1000 hours at a high temperature and high humidity of 85 ° C. and 85% humidity was observed, the sample coated with the protective member A (using ethylene polymer resin) was corroded on the electrode part. Although it was observed, the sample coated with the protective member B (using EVA resin) showed no corrosion at the electrode portion.

As shown in Table 5 and Table 6, when the sample covered with the protective member B among the samples 101 to 115 is compared with the other samples, the former sample has suppressed performance fluctuations before and after storage.
Therefore, in order to suppress deterioration of the characteristics (performance) of the organic EL element with respect to high temperature and high humidity treatment, a thermosetting resin (adhesive) having a crosslinking temperature of 110 ° C. or higher is used as a protective member and 110 ° C. It can be seen that it is useful to heat-press and heat cure at the above temperature.
Further, in the former sample, corrosion of the electrode portion is suppressed, and the organic EL module of the present invention is very useful for a large panel or the like in which a plurality of small panels (organic EL elements) are arranged. Recognize.

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Anode 3 Organic compound layer 4 Cathode 5 Sealing member (sealing resin)
DESCRIPTION OF SYMBOLS 10 Protective member 11 Protective substrate 12 Adhesive layer 20, 21 Extraction electrode 100 Organic EL module 301 Hole injection layer 302 Hole transport layer 303 Light emitting layer 304 Hole blocking layer 305 Electron transport layer

Claims (8)

In an organic EL element in which an anode, an organic compound layer and a cathode are formed on a support substrate,
The organic compound layer has at least a hole transport layer, a light emitting layer and an electron transport layer;
The hole transport layer is composed of a hole transport material,
The light emitting layer is composed of a host compound and a light emitting dopant,
The electron transport layer is composed of an electron transport material;
All the glass transition points Tg of the hole transport material, the host compound and the electron transport material excluding the light emitting dopant are 110 ° C. or more, and the electron transport layer is selected from alkali metals or alkaline earth metals An organic EL device comprising at least one kind of metal or a metal compound thereof. The organic EL device according to claim 1,
The organic EL device, wherein the electron transport material has a phenylpyridine group. The organic EL device according to claim 1 or 2,
An organic EL device, wherein the metal compound is an alkali metal fluoride. In the organic EL element according to any one of claims 1 to 3,
An organic EL element, wherein a hole blocking layer is formed between the light emitting layer and the electron transporting layer. In the organic EL element according to any one of claims 1 to 4,
An organic EL element, wherein an electron injection layer is formed between the electron transport layer and the cathode. The organic EL device according to any one of claims 1 to 5,
A sealing member for sealing the organic EL element with a part of the anode and the cathode exposed;
A protective member that protects the sealing member and a part of the anode and the cathode exposed from the sealing member, and the protective member made of a thermosetting resin having a temperature of 110 ° C. or higher when bonded;
An organic EL module comprising: The organic EL module according to claim 6,
The organic EL module, wherein the protective member comprises at least an adhesive layer and a protective substrate. Forming the organic EL element according to any one of claims 1 to 5;
Sealing the organic EL element with a portion of the anode and cathode exposed;
A protective member made of a thermosetting resin having a crosslinking temperature of 110 ° C. or higher, covering the organic EL element sealing body and a part of the anode and cathode exposed therefrom, and the protective member portion being 110 ° C. or higher. Heating at a temperature;
A method for producing an organic EL module, comprising:

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