JP2002203674A - Organic electroluminescence element and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescence element in which a luminous pattern of fine line width can be formed in any shape, and improvement of manufacturing efficiency and reduction of manufacturing cost can be made by forming easily a layer of uniform thickness, and a manufacturing method of the organic electroluminescence element. SOLUTION: An organic luminous layer 4 that is interposed between the positive electrode layer 3 and negative electrode layer 5 is formed by an offset printing method. The organic luminous layer 4 is made by heating and drying the painted membrane of an organic luminous paint in which an electron transport material, a hole transport material, a host polymer and fluorescent pigment are mixed and dissolved uniformly in an organic solvent, or a polymer having electron transportability, hole transportability and fluorescence is dissolved in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic electroluminescence device (hereinafter, also referred to as an organic EL device) and a method for manufacturing the same.

[0002]

2. Description of the Related Art Organic electroluminescent devices are
A positive electrode layer, a light-emitting layer containing an organic light-emitting material formed on the positive electrode layer (hereinafter also referred to as an organic light-emitting layer), and a negative electrode layer formed on the organic light-emitting layer; When a predetermined voltage is applied to the layer and the negative electrode layer from a DC power supply, holes are injected from the positive electrode layer into the organic light emitting layer, and electrons are injected from the negative electrode layer. Then, electrons and holes recombine in the organic light emitting layer to generate excitons (excitons), and light is emitted by emission of light (luminescence) when the excitons are deactivated.

[0003]

A conventional organic EL device is provided on a substrate made of glass, synthetic resin film or the like.
A positive electrode layer such as a TO (indium oxide film) is formed by vacuum deposition, and an organic light emitting layer and a negative electrode layer are sequentially formed on the positive electrode layer by vacuum deposition, spin coating, or the like. I have. The organic EL element needs to form a layer thickness of a positive electrode layer, an organic light emitting layer, a negative electrode layer and the like uniformly and sequentially laminate them.
It takes time and effort to form each layer.

Further, when the shape of the light emitting portion of the organic EL element, that is, the light emitting pattern is set to an arbitrary shape,
A mask having holes of a predetermined shape is placed on the substrate, and a patterning step of forming at least one or more of the positive electrode layer, the organic light-emitting layer, and the negative electrode layer into the predetermined shape by a vacuum deposition method or the like must be performed. There is. In particular, in the case of an organic EL element that emits light in a plurality of colors, it is necessary to repeatedly perform a patterning step by a vacuum deposition method or the like using a different mask for each organic light-emitting material to be used, that is, for each light-emitting color when forming an organic light-emitting layer. Therefore, the manufacturing cost is high, and improvement is required in terms of improving production efficiency.

In the patterning step by the vacuum deposition method, it is necessary to process a mask to be used with high precision and to position it at a predetermined position on a substrate with high precision. In particular, a pattern having a fine line width (for example, , Line width is 0.1mm or less)
When forming is, there is a tendency that it takes time and effort.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to easily form a light emitting pattern having a fine line width into an arbitrary shape and easily form a layer having a uniform thickness. It is an object of the present invention to provide an organic electroluminescent device and a method for manufacturing the organic electroluminescent device, which can be formed to improve production efficiency and reduce manufacturing cost.

[0007]

The organic electroluminescence device according to the present invention has at least a positive electrode layer, a negative electrode layer, and an organic light emitting layer interposed between the positive electrode layer and the negative electrode layer. The organic light emitting layer is formed by an offset printing method.

The organic light emitting layer is formed of a coating film of an organic light emitting paint in which an electron transporting material, a hole transporting material, a host polymer and a fluorescent dye are mixed and dissolved in an organic solvent.

The organic light emitting layer is formed of a coating film of an organic light emitting paint in which a polymer having an electron transporting property, a hole transporting property and a fluorescent property is dissolved in an organic solvent.

[0010] Further, the device has a hole transport layer interposed between the positive electrode layer and the organic light emitting layer.

[0011] Further, an electron transport layer is provided between the organic light emitting layer and the negative electrode layer.

Further, the hole transport layer is formed by at least one method selected from an offset printing method, a screen printing method, a gravure printing method and a spin coating method, and comprises a hole transporting material and an electron accepting acceptor. It consists of a coating film of a hole transporting paint dissolved in an organic solvent.

The electron transport layer is formed by at least one method selected from an offset printing method, a screen printing method, a gravure printing method, and a spin coating method, and is formed by dissolving an electron transporting material in an organic solvent. It consists of a coating film of a transportable paint.

The organic light emitting layer has a thickness of 0.01.
It is in the range of μm to 5 μm.

Further, according to the method of manufacturing an organic electroluminescence device according to the present invention, a positive electrode layer comprising a metal, an alloy, an electrically conductive compound and a mixture thereof having a large work function is formed on a substrate, and an electron transporting material, An organic light-emitting paint in which a hole-transporting material, a host polymer and a fluorescent dye are mixed and uniformly dissolved in an organic solvent, or a polymer having electron-transporting, hole-transporting, and fluorescent properties is dissolved in an organic solvent. An organic light-emitting paint is prepared, an organic light-emitting paint coating film is formed on the positive electrode layer by offset printing, heated and dried to form an organic light-emitting layer, and a work function is formed on the organic light-emitting layer. Is to form a negative electrode layer made of a metal, an alloy, an electrically conductive compound and a mixture thereof.

Further, according to the method of manufacturing an organic electroluminescence device according to the present invention, a positive electrode layer made of a metal, an alloy, an electrically conductive compound or a mixture thereof having a large work function is formed on a substrate, and a hole transporting material is formed. And preparing a hole-transporting paint in which an electron-accepting acceptor is dissolved in an organic solvent, and at least one method selected from offset printing, screen printing, gravure printing, and spin coating on the positive electrode layer. Forming a coating film of the hole-transporting paint, heating and drying to form a hole-transporting layer, and mixing an electron-transporting material, a hole-transporting material, a host polymer and a fluorescent dye in an organic solvent. Prepare an organic luminescent paint uniformly dissolved in, or an organic luminescent paint in which a polymer having electron transporting property, hole transporting property and fluorescent property is dissolved in an organic solvent, A coating film of the organic luminescent paint is formed on the hole transport layer by an offset printing method, and the organic luminescent layer is formed by heating and drying. The work function is small on the organic luminescent layer. A negative electrode layer made of a compound and a mixture thereof is formed.

Further, according to the method of manufacturing an organic electroluminescence device according to the present invention, a positive electrode layer comprising a metal, an alloy, an electrically conductive compound and a mixture thereof having a large work function is formed on a substrate, and an electron transporting material, An organic light-emitting paint in which a hole-transporting material, a host polymer and a fluorescent dye are mixed and uniformly dissolved in an organic solvent, or a polymer having electron-transporting, hole-transporting, and fluorescent properties is dissolved in an organic solvent. Prepare an organic luminescent paint, form a coating film of the organic luminescent paint by offset printing method on the positive electrode layer, heat and dry to form an organic luminescent layer, the electron transporting material in an organic solvent Prepare an electron-transporting paint uniformly dissolved in, and at least select from offset printing, screen printing, gravure printing and spin coating on the organic light-emitting layer. Metal 1 or the method by heating and drying to form a coating film of the electron-transporting coating to form an electron transport layer, the work function on the electron transport layer small,
A negative electrode layer made of an alloy, an electrically conductive compound, and a mixture thereof is formed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an organic electroluminescence device and a method of manufacturing an organic electroluminescence device according to the present invention will be described with reference to the drawings.

First, a first embodiment of an organic electroluminescence device (including a method of manufacturing an organic electroluminescence device) according to the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 1 (a)
1 is a plan view showing an organic electroluminescence device as a first embodiment according to the present invention, and FIG.
It is AA sectional drawing in FIG.1 (a).

As shown in FIGS. 1A and 1B, an organic electroluminescence element (hereinafter, also referred to as an organic EL element) 1a is a so-called single-layer organic EL element.
A device, a substrate 2, a positive electrode layer 3, a negative electrode layer 5,
A light emitting layer (hereinafter, also referred to as an organic light emitting layer) 4 containing an organic material interposed between the positive electrode layer 3 and the negative electrode layer 5;
In the present embodiment, the positive electrode layer 3 is formed on the substrate 2,
An organic light emitting layer 4 is formed on the positive electrode layer 3, and then a negative electrode layer 5 is sequentially laminated on the organic light emitting layer 4. And
The organic light emitting layer 4 emits light by applying a predetermined voltage from the DC power supply to the positive electrode layer 3 and the negative electrode layer 5. In the present embodiment, each layer is formed in a different shape,
The shape of the light emitting portion, that is, the light emitting pattern is the shape of the portion where the positive electrode layer 3, the organic light emitting layer 4, and the negative electrode layer 5 overlap each other (broken line portion F in FIG. 1A). The order of laminating each layer is not limited to this, and a configuration in which the negative electrode layer 5 is formed on the substrate 2 and then the organic light emitting layer 4 and the positive electrode layer 3 are sequentially laminated may be employed.

The substrate 2 is formed in a flat plate shape and is made of one or more materials selected from synthetic resins such as polyethylene terephthalate, polycarbonate, polyester, etc., glass, quartz and the like. It is preferable that the visible light transmittance is 70% or more.

The positive electrode layer 3 has a large work function (4 eV
Above) One or more substances selected from metals, alloys, electrically conductive compounds and mixtures thereof, for example, gold,
Metals such as platinum, Mg-Ag alloy, or CuI, I
One or more substances selected from electrically conductive transparent materials such as TO (indium oxide film), SnO ₂ , and ZnO can be used. When light emission of the organic EL element 1a is extracted from the positive electrode layer 3, the visible light transmittance of the positive electrode layer 3 is preferably set to 10% or more. Further, the resistance value of the positive electrode layer 3 is several hundred Ω / sq. Preferably, the thickness of the positive electrode layer 3 is set in the range of 10 nm to 1 μm, preferably 50 to 200 nm.

The method for forming the positive electrode layer 3 is not particularly limited, and examples thereof include a vacuum deposition method, a direct current (DC) sputtering method,
High frequency (RF) sputtering, spin coating, etc.
It is formed on the substrate 2.

Next, an organic light emitting layer 4 is formed on the positive electrode layer 3. The organic light emitting layer 4 is prepared by uniformly dissolving an organic light emitting material obtained by mixing an electron transporting material, a hole (hole) transporting material, a host polymer and a fluorescent dye in an organic solvent to prepare an organic light emitting paint. An organic luminescent coating is formed on the positive electrode layer 3 by an offset printing method to form a coating film, which is then heated and dried.

The concentration of the organic luminescent material with respect to the organic solvent is preferably in the range of 1% by mass to 15% by mass, more preferably in the range of 3% by mass to 8% by mass. The organic solvent is not particularly limited as long as it can dissolve the organic light-emitting material.However, when the evaporation rate of the organic solvent is high, the viscosity of the prepared organic light-emitting paint increases, and the organic light-emitting paint is easily fixed to the printing plate. 25 ° C of the organic solvent
Is preferably in the range of 0.1 to 20 mmHg, and the boiling point is in the range of 100 to 300 ° C. Examples of such organic solvents include cyclohexanone, chlorobenzene, o-dichlorobenzene, tetralin, 1,2,4-trichlorobenzene, 1,1,2,2.
One or more substances selected from 2-tetrachloroethane, tetralin, N, N-dimethylformamide, diethyl carbitol and the like can be used.

As the electron transporting material, 1,3,3
4-oxadiazole derivative (OXD), 1,2,4-
Triazole (TAZ), tris (8-hydroxyquinolinato) aluminum (Alq ₃ ), 2- (4-biphenylyl) -5- (4-t-butyl-phenyl) -1,
One or more substances selected from 3,4-oxadiazole (PBD), 2,5- (binaphthyl) -1,3,4-oxadiazole (BND) and the like can be used.

As the hole-transporting material, one or more substances selected from tetraarylbendicine compounds, aromatic amines, pyrazoline derivatives, triphenylene derivatives and the like can be used. TPD) is preferred.

As the host polymer, polystyrene, polymethyl methacrylate (PMMA), polyvinyl carbazole (PVCz), polyoxadiazole derivative, polytetraphenylbenzine derivative (p-TPD), polyfluorene compound, polythiophene compound, polythiophene compound One or more substances selected from paraphenylene vinylene derivatives and the like can be used. The polymer is a polymer having a hole transporting unit containing two or more (preferably three or more) aromatic rings, and is not conjugated to the main chain. Preferably, it contains a group. As a compound containing two aromatic rings and containing a non-conjugated group in the main chain, polyvinyl carbazole (PVCz) is preferable.

Examples of the compound containing three or more aromatic rings and a non-conjugated group in the main chain are selected from diamine, triarylamine oligomer, thiophene oligomer, arylenevinylene oligomer and styrylamine. An organic compound containing three or more aromatic rings consisting of units derived from a compound (also referred to as a hole transport unit) as an ester group,
Ether group, carbonate group, urethane group, amide group,
Examples of the polymer include a sulfone group and a polymer linked by a linking group having a non-conjugated group such as a ketone group.
Copoly [3,3'-hydroxytetraphenylbenzine / diethylene glycol] carbonate (hereinafter referred to as PC-TPD-DEG) represented by the following structural formula, copoly [3,3'-hydroxytetraphenylbenzine / hexamethylene] carbonate (Hereinafter, PC-TPD
-HM).

[0030]

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[0031]

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As the fluorescent dye, one or more substances selected from coumarin, DCM derivative, quinacridone, perylene, rubrene, tetraphenylbutadiene, distyrylanthracene and the like can be used, and by appropriately selecting these fluorescent dyes, , A predetermined emission color can be obtained.

The electron transporting material, holes
An organic luminescent material is prepared by mixing a transport material, a host polymer, and a fluorescent dye, and the organic luminescent material is uniformly dissolved in an organic solvent to obtain an organic luminescent coating.
When a polymer having both electron transporting property, hole transporting property and fluorescent property is used, only the polymer may be dissolved alone in an organic solvent to prepare an organic luminescent coating.
Examples of the polymer having both electron transporting property, hole transporting property and fluorescence property include polyalkylfluorene.

The thickness of the organic light emitting layer 4 is preferably set in the range of 0.01 to 5 μm, more preferably 0.03 to 0.5 μm, in order to obtain practical luminous efficiency. In the organic EL element 1a according to the present invention, the organic light emitting layer 4 is formed by the offset printing method. However, according to the offset printing method, a relatively thin layer can be easily formed uniformly with high accuracy. . That is, the organic light emitting layer 4
Since the luminous efficiency can be improved by forming a thin film, the organic EL element 1a according to the present invention has a high luminous efficiency, is inexpensive to manufacture, and can easily form an arbitrary luminous pattern with high accuracy. It can be formed.

Next, the negative electrode layer 5 is formed on the organic light emitting layer 4. The negative electrode layer 5 has a small work function (4 eV or less).
It comprises one or more substances selected from metals, alloys, electrically conductive compounds and / or mixtures thereof, for example, N 2
a, K, Mg, Li, In, rare earth metals, Na · K alloy, Mg · Ag alloy, Mg · Cu alloy, Al · Li alloy, one or more substances selected from such as Al / Al ₂ O ₃ mixture used It is possible. Note that the organic EL is
When taking out the light emission of the element 1a, it is preferable to set the visible light transmittance of the negative electrode layer 5 to 10% or more. The resistance value of the negative electrode layer 5 is several hundred Ω / sq. The thickness of the negative electrode layer 5 is preferably 10 nm to 1 μm.
m, preferably in the range of 50 to 200 nm.

The method for forming the negative electrode layer 5 is not particularly limited. For example, a vacuum deposition method, a direct current (DC) sputtering method,
High frequency (RF) sputtering, spin coating, etc.
It is formed on the substrate 2.

Next, the offset printing method included in the method for manufacturing an organic EL device according to the present invention will be described.

In the offset printing method, the ink image of the printing plate is once transferred to the surface of a blanket (transfer member) made of an elastic material such as rubber without directly printing the printing plate from the printing plate. This is a method of printing an ink image on a printing medium. Depending on the printing plate used, it can be broadly classified into a flat plate offset printing method, a letterpress offset printing method, an intaglio offset (for example, gravure offset) printing method, and the like.

In the intaglio offset (eg, gravure offset) printing method, a number of recesses called cells are formed on the surface of the printing plate by photoengraving, laser processing, or the like. After transferring the ink in the concave portion onto the (transfer), the print is passed between a rubber roll (or table) called an impression cylinder and a blanket (transfer), and the ink is transferred to the print by applying pressure. This is the method of printing. Therefore, by appropriately setting the shape, cross-sectional area, depth and the like of the concave portion (cell) formed on the surface of the printing plate, the amount of transferred ink can be adjusted, and the thickness of the film formed by printing can be adjusted. This is particularly preferable because the degree can be set arbitrarily.

Then, the prepared organic luminescent paint was filled in the concave portion (cell) of the offset printing plate having a predetermined luminescent pattern formed thereon, and the positive electrode layer 3 was formed between the impression cylinder and the blanket (transfer member). When the substrate 2 is inserted, a coating film of an organic luminescent paint can be formed on the positive electrode layer 3. When this coating film is heated and dried, it is formed into a predetermined luminescence pattern, and an organic film having a uniform thickness is formed. The light emitting layer 4 can be easily formed. Therefore, in the organic EL element 1a, a layer having a uniform thickness can be easily formed into an arbitrary light emitting pattern shape by the offset printing method, and the layer thickness can be set to be thin with high accuracy. Therefore, the production efficiency is high and the production cost can be reduced.

The printing plate of the offset printing method according to the present invention can use various materials such as rubber, synthetic resin, and metal, but use a material such as metal having a predetermined rigidity with little elastic deformation. It is preferable that the light emitting pattern can be formed with higher precision. In addition, the offset printing method,
Since the printing plate is not in direct contact with the printing substrate, the printing substrate is in contact with a blanket (transfer member) made of an elastic body to which the ink image of the printing plate has been transferred, and printing is performed. Even if a material having rigidity such as metal is used for the plate, the organic light emitting layer 4 can be formed on the substrate 2 made of, for example, glass without damaging the printing medium. Therefore, the method for manufacturing an organic electroluminescence element according to the present invention has a large degree of freedom in selecting the material of the substrate 2 as a printing medium, and the organic light emitting layer 4
Since the transfer image is a transfer image of the ink image of the printing plate formed with high precision, it is possible to form a light emission pattern with a fine line width with high precision.

The formation of the organic light emitting layer 4 by the offset printing method can be automated using an offset printing machine. However, when the organic EL element 1a that emits light of a plurality of colors is manufactured, each light to be emitted is emitted. If the printing is performed using an offset printing machine provided with an organic luminescent paint exhibiting the above, and an offset printing plate having a pattern shape corresponding to the luminescent color, the organic E which emits light in a plurality of colors in a single printing process.
The L element 1a can be formed.

Although the organic light emitting layer 4 is formed by offset printing in this embodiment, a flexographic printing method may be used. The flexographic printing method is a type of letterpress printing, in which ink is supplied to a roller formed with cells called anilox rolls, and an appropriate amount of ink is supplied from the anilox roll to a thick and soft printing plate that contacts the anilox roll. This is a method of printing while supplying, wherein a printing medium is printed by being inserted between a printing plate and an impression cylinder. Therefore, the amount of ink supplied from the anilox roll can be adjusted by appropriately setting the shape of the cell formed on the anilox roll, the cross-sectional area, the size such as the depth, or the contact pressure between the anilox roll and the printing plate. In addition, the thickness of a film formed by printing can be arbitrarily set.

Next, a second embodiment of the organic electroluminescence device (including a method of manufacturing an organic electroluminescence device) according to the present invention will be described with reference to FIG.
Description will be made with reference to (a) and (b). FIG. 2 (a)
FIG. 2B is a plan view showing an organic electroluminescence element according to a second embodiment of the present invention, and FIG.
It is an AA sectional view in (a). In addition, FIG.
The organic EL device according to the second embodiment of the present invention shown in FIGS. 1 and 2 has the same basic configuration as the organic EL device according to the first embodiment shown in FIGS. 1A and 1B. For this reason, in the following description, differences will be mainly described, and other portions will be described only as main portions. FIG.
In (a) and (b), parts having the same configuration and operation as those of the organic EL element shown in FIGS. 1 (a) and (b) are denoted by the same reference numerals.

As shown in FIGS. 2A and 2B, an organic EL device 1b according to a second embodiment of the present invention
Represents a substrate 2, a positive electrode layer 3, and a hole transporting layer 6.
And a light-emitting layer (organic light-emitting layer) 4 containing an organic material, and a negative electrode layer 5. In the present embodiment, the positive electrode layer 3 is formed on the substrate 2, and the positive electrode layer 3 is formed on the positive electrode layer 3. Hole transport layer 6
Is formed, the organic light emitting layer 4 is formed on the hole transport layer 6, and then the negative electrode layer 5 is sequentially laminated on the organic light emitting layer 4. When a predetermined voltage is applied from the DC power supply to the positive electrode layer 3 and the negative electrode layer 5, the organic light emitting layer 4 emits light.

Therefore, the organic EL device 1b according to the second embodiment of the present invention is provided between the positive electrode layer 3 and the organic light emitting layer 4 of the organic EL device 1a according to the first embodiment. In this embodiment, a hole transporting layer 6 is provided, and the other configuration is the same. In the present embodiment, each layer is formed in a different shape, and the shape of the light emitting portion, that is, the light emitting pattern is such that the positive electrode layer 3, the hole transport layer 6, the organic light emitting layer 4, and the negative electrode layer 5 are formed. This is the shape of the overlapping portion (broken line portion F in FIG. 2A). The order of laminating the layers is not limited to this, and the negative electrode layer 5 is formed on the substrate 2, and then the organic light emitting layer 4, the hole transport layer 6, and the positive electrode layer 3 are sequentially laminated. Is also good.

The hole transporting layer 6 has a function of facilitating the injection of holes into the organic light emitting layer 4. The hole transporting layer raw material obtained by mixing a hole transporting material and an electron accepting acceptor is mixed in an organic solvent. A hole-transporting paint is prepared by dissolving uniformly, and the hole-transporting paint is formed on the positive electrode layer 3 by one or more methods selected from offset printing, screen printing, gravure printing, and spin coating. It is formed by coating to form a coating film, heating and drying.

The concentration of the hole transport layer raw material relative to the organic solvent is preferably in the range of 1% by mass to 15% by mass, and more preferably in the range of 3% by mass to 8% by mass. The organic solvent is not particularly limited as long as it can dissolve the hole transport layer material, but if the evaporation rate of the organic solvent is high, the viscosity of the prepared hole transport paint increases, It is preferable that the vapor pressure of the organic solvent at 25 ° C. is in the range of 0.1 to 20 mmHg and the boiling point is in the range of 100 to 300 ° C., since the transportable paint is easily fixed. Examples of such organic solvents include cyclohexanone, chlorobenzene, o-dichlorobenzene,
Tetralin, 1,2,4-trichlorobenzene, 1,
1,2,2-tetrachloroethane, tetralin, N, N
One or more substances selected from dimethylformamide, diethyl carbitol and the like can be used.

As the hole transporting material, one or more substances selected from tetraarylbendicine compounds, aromatic amines, pyrazoline derivatives, triphenylene derivatives and the like can be used. For example, tetraphenyldiamine ( TPD) is preferred.

The electron-accepting acceptor is intended to improve the hole-transporting property, and is not particularly limited as long as it oxidizes the hole-transporting material. For example, it is preferably at least one selected from metal halides, Lewis acids, organic acids, salts of arylamines and metal halides, and salts of organic acids and arylamines with Lewis acids. These may be used in combination.

Preferred examples of the metal halide and Lewis acid include FeCl ₃ , AlCl ₃ , SbCl ₅ , AsF ₅ ,
BF _{3 and the} like.

Examples of the organic acid include the following general formula (1)
And the compound represented by the formula:

[0053]

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In the above general formula (1), A is an acid group such as a sulfonic acid group, a phosphoric acid group, a boric acid group and a carboxylic acid group. R represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group, an alkylthio group, an alkoxyalkyl group having 2 to 20 carbon atoms, an alkylthioalkyl group, an alkenyl group, a cycloalkyl group having 5 to 20 carbon atoms, and a 6 to 20 carbon atoms. Aryl group, an alkaryl group having 7 to 20 carbon atoms, an aralkyl group, a heterocyclic group such as a pyridyl group, a quinolyl group, a furanyl group, a pyrrolyl group, a thienyl group, or a halogen atom, a nitro group, a cyano group And an epoxy group. m is a positive number from 0 to 5. When m is 2 or more, Rs may be the same or different from each other.

Further, other examples of the organic acid include polymer acids such as sulfonated polystyrene, sulfonated polyethylene and sulfonated polycarbonate, and polymer acids such as acrylic acid polymer.

A salt of an arylamine with a metal halide,
Examples of the salt of an arylamine with a Lewis acid include a salt represented by the following general formula (2).

[0057]

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In the above general formula (2), L is a metal halide or a Lewis acid.
l ₃ , AlCl ₃ , SbCl ₅ , AsF ₅ , BF _{3 and the} like. X ^- is preferably a halogen ion. Ar ^{11 to} Ar ¹³ are each independently a substituted or unsubstituted aromatic group or heterocyclic group having 5 to 30 carbon atoms. Preferred substituents include a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 24 carbon atoms, an aryl group having 6 to 24 carbon atoms, an aralkyl group having 7 to 24 carbon atoms, and an alkoxy group having 1 to 24 carbon atoms. An aryloxy group having 6 to 24 carbon atoms, a mono- or dialkylamino group having 1 to 24 carbon atoms in an alkyl group, and 6 carbon atoms in an aryl group.
To 24 mono- or diarylamino groups.

Among the salts represented by the above general formula (2), a preferable example is a tris (4-bromophenyl) ammonium hexachloroantimonate (hereinafter, referred to as TBAHA) represented by the following structural formula. be able to.

[0060]

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If the hole transport layer 6 is formed by one or more methods selected from offset printing, screen printing, gravure printing, and spin coating, a layer having a uniform thickness can be easily formed. However, according to the offset printing method included in the method for manufacturing an organic EL device according to the present invention, the layer thickness of the hole transport layer 6 can be arbitrarily set in the range of 0.01 to 5 μm, and the height can be increased to an arbitrary shape. It can be formed uniformly with accuracy.

Further, the organic light emitting layer 4 comprises the organic EL element 1a
What is necessary is just to form by the same component and manufacturing method. Therefore, the organic EL element 1b can easily form a layer having a uniform thickness into an arbitrary light emitting pattern shape by offset printing, and can form a light emitting pattern having a fine line width with high accuracy. Since the layer thickness can be set to be thin, luminous efficiency and production efficiency are high, and manufacturing cost can be reduced. Since the organic EL element 1b has the hole transporting layer 6, the organic light emitting layer 4 may be formed only of the electron transporting material, the host polymer, and the fluorescent dye without mixing the hole transporting material with the organic light emitting layer 4. . In addition, if the hole transport layer 6 is formed by the offset printing method of the present invention in addition to the organic light emitting layer 4, the hole transport layer 6 and the organic light emitting layer 4 can be fully automated using one offset printing machine. It is possible and preferred.

The organic electroluminescence device and the method for manufacturing the organic electroluminescence device according to the present invention are the same as those of the organic EL device 1 according to the first embodiment.
a and the configuration of the organic EL element 1b as the second embodiment is not limited, and can be appropriately changed. For example, the organic EL element 1b according to the first embodiment of the present invention can be modified.
Element 1a and Organic EL Element 1 as Second Embodiment
b, the organic light emitting layer 4 and the negative electrode layer 5
May be provided with an electron transport layer interposed therebetween.

The electron transporting layer has a function of facilitating the injection of electrons into the organic light emitting layer 4. An electron transporting material is uniformly dissolved in an organic solvent to prepare an electron transporting paint. The coating is formed on the organic light emitting layer 4 by applying at least one method selected from an offset printing method, a screen printing method, a gravure printing method and a spin coating method to form a coating film, and the coating film is formed by heating and drying. I do.

The concentration of the electron transporting material with respect to the organic solvent is preferably in the range of 1% by mass to 15% by mass, more preferably in the range of 3% by mass to 8% by mass. The organic solvent is not particularly limited as long as it can dissolve the electron transporting material. However, when the evaporation rate of the organic solvent is high, the viscosity of the electron transporting paint to be prepared is increased, and the electron transporting paint is added to the printing plate. It is preferable that the vapor pressure of the organic solvent at 25 ° C. is in the range of 0.1 to 20 mmHg and the boiling point is in the range of 100 to 300 ° C. Examples of such organic solvents include cyclohexanone, chlorobenzene, o-dichlorobenzene,
Tetralin, 1,2,4-trichlorobenzene, 1,
1,2,2-tetrachloroethane, tetralin, N, N
One or more substances selected from dimethylformamide, diethyl carbitol and the like can be used.

Examples of the electron transporting material include 1,3,4-oxadiazole derivative (OXD), 1,2,4-triazole (TAZ), tris (8-hydroxyquinolinato) aluminum (Alq ₃ ), Chelating metal complexes of zinc with ligands such as oxadiazole, thiadiazole, phenylpyridine, phenylbenzoylimidazole, quinoline, poly1,3,4-oxadiazole derivatives, polyfluorene compounds, polythiophene compounds, polypara One or more substances selected from phenylene vinylene derivatives and the like can be used.

Then, the electron transporting material is uniformly dissolved in the organic solvent to obtain an electron transporting paint. The electron transport layer is selected from offset printing, screen printing, gravure printing, and spin coating.
When formed by the above method, a layer having a uniform thickness can be easily formed. However, according to the offset printing method included in the method for manufacturing an organic EL device according to the present invention, the layer thickness of the electron transport layer is set to 0.1. It can be arbitrarily set within the range of 01 to 5 μm, and can be uniformly formed with high accuracy in an arbitrary shape.

When an electron transporting layer is formed on the organic EL element 1a and the organic EL element 1b, the organic light emitting layer 4 may be formed without mixing an electron transporting material. Also,
If an electron transport layer is formed by the offset printing method of the present invention in addition to the organic light emitting layer 4 (and the hole transport layer 6), the electron transport layer and the organic light emitting layer 4 (and The hole transport layer 6) can be formed fully automatically, which is preferable.

[0069]

EXAMPLES (Example 1) An ITO thin film was formed on a glass substrate 2 having a thickness of 1100 μm by a vacuum evaporation method so as to have a surface resistance of 10 Ω / sq, and this ITO thin film was etched by a photolithography process. FIG.
The positive electrode layer 3 having the shape shown in (a) and (b) was formed.
The thickness of the formed positive electrode layer 3 was 0.15 μm. Next, in order to form the organic light emitting layer 4 by an intaglio offset (for example, gravure offset) printing method, CT
An organic light emitting material was prepared by mixing P-5, PBD, and coumarin 6, and dissolved in an organic solvent in which o-dichlorobenzene and 1,2,4-trichlorobenzene were mixed at a weight ratio of 1: 1 to form an organic material. A luminescent coating was prepared. The weight ratio of each substance is
CTP-5: PBD: Coumarin 6: Organic solvent = 3: 2:
0.05: 105.

Next, an offset printing plate in which a recess (cell) having a depth of 20 μm is formed in a predetermined light emitting pattern shape is mounted on an offset printing machine, and an adjusted organic light emitting paint is supplied to form an ITO thin film. A coating film of an organic luminescent paint was formed on the electrode layer 3 by an intaglio offset (for example, gravure offset) printing method. Then, the coating film was dried by heating at 80 ° C. in vacuum to form the organic light emitting layer 4. The thickness of the formed organic light emitting layer 4 is 0.11 μm
Met.

Next, a thin stainless steel plate that exposes only the portion where the negative electrode layer 5 is to be formed is mounted on the formed organic light emitting layer 4 as a mask, and a 200 nm thick Mg / Ag alloy is deposited thereon. After the vacuum deposition, the mask was removed to form a negative electrode layer 5. The luminance at a voltage of 20 V was 75 cd / m 2.

CTP-5 is a kind of tetraphenylbenzine derivative and is represented by the following structural formula.

[0073]

Embedded image

(Example 2) On a polyester film substrate 2 having a thickness of 125 µm, an ITO thin film was coated with a surface resistance of 50 Ω /
sq, and this ITO
The positive electrode layer 3 having the shape shown in FIGS. 2A and 2B was formed by etching the thin film by a photolithography process. The thickness of the formed positive electrode layer 3 is 0.13 μm.
m. Next, in order to form the hole transport layer 6 by a screen printing method, CTP-5 and TBAHA are mixed to prepare a hole transport layer material, and o-dichlorobenzene and
It was dissolved in an organic solvent in which 1,2,4-trichlorobenzene was mixed at a weight ratio of 1: 1 to prepare a hole transporting paint.
The weight ratio of each substance is CTP-5: TBAHA: organic solvent = 9: 1: 190.

Next, a screen plate having a thickness of 20 μm was mounted on a screen printing machine, and the adjusted hole transporting paint was supplied to the positive electrode layer 3 so as to form a hole transporting layer having the shape shown in FIG. The coating film of the conductive paint was formed by a screen printing method. Then, this coating film was dried by heating at 80 ° C. in a vacuum to form the hole transport layer 6. The thickness of the formed hole transport layer 6 was 0.13 μm.

Next, in order to form the organic light emitting layer 4 by intaglio offset (for example, gravure offset) printing, CTP-5, PBD and coumarin 6 are mixed to prepare an organic light emitting material, and o-dichlorobenzene is prepared. And 1,2,4
An organic luminescent paint was prepared by dissolving in an organic solvent in which trichlorobenzene was mixed at a weight ratio of 1: 1. The weight ratio of each substance is CTP-5: PBD: coumarin 6: organic solvent =
3: 2: 0.05: 125.

Next, an offset printing plate in which a recess (cell) having a depth of 20 μm is formed in a predetermined light emitting pattern shape is mounted on an offset printing machine, and the adjusted organic light emitting paint is supplied to supply the hole transport layer 6. A coating film of an organic luminescent paint was formed thereon by an intaglio offset (eg, gravure offset) printing method. Then, this coating film is 80
The organic light-emitting layer 4 was formed by drying by heating at a temperature of ° C. The thickness of the formed organic light emitting layer 4 was 0.08 μm.

Next, a thin stainless steel plate that exposes only the portion where the negative electrode layer 5 is to be formed is placed on the formed organic light emitting layer 4 as a mask, and a Mg.Ag alloy having a thickness of 200 nm is placed thereon. After the vacuum deposition, the mask was removed to form a negative electrode layer 5. The luminance at a voltage of 20 V was 50 cd / m 2.

[0079]

As described above, according to the organic electroluminescence device and the method of manufacturing an organic electroluminescence device according to the present invention, a light emitting pattern having a fine line width can be easily formed into an arbitrary shape. In addition, it is possible to easily form a layer having a uniform thickness, thereby improving the production efficiency and reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1A is a plan view showing an organic electroluminescence element according to a first embodiment of the present invention,
(B) is an AA sectional view in (a).

FIG. 2A is a plan view showing an organic electroluminescence element according to a second embodiment of the present invention,
(B) is an AA sectional view in (a).

[Explanation of symbols]

1a Organic EL Device (First Embodiment) 1b Organic EL Device (Second Embodiment) 2 Substrate 3 Positive Electrode Layer 4 Organic Light Emitting Layer 5 Negative Electrode Layer 6 Hole (Hole) Transport Layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akio Taniguchi 3-14-2 Chuo, Ueda-shi, Nagano Menage Ueda 602 (72) Inventor Masahiro Tamura 238-2 Oga, Yoga, Suwa-City, Nagano Prefecture Inside Fujiname Plate Co., Ltd. (72) Inventor Harutoshi Niwa 238-2 Oga Yoga, Suwa City, Nagano Prefecture Inside Fujiname Plate Co., Ltd. (72) Inventor Kazuki 238-2 Oga Shiga, Suwa City, Nagano Prefecture 2Fuji Term Plate Co., Ltd. F term (reference) 3K007 AB18 CA01 CA06 CB01 DA01 DB03 EB00 FA01

Claims (11)

[Claims] At least a positive electrode layer, a negative electrode layer, and an organic light emitting layer interposed between the positive electrode layer and the negative electrode layer, wherein the organic light emitting layer is formed by an offset printing method. An organic electroluminescent device, comprising: 2. The organic light-emitting layer comprises a coating film of an organic light-emitting paint in which an electron transporting material, a hole transporting material, a host polymer and a fluorescent dye are mixed and dissolved in an organic solvent. The organic electroluminescence device according to claim 1, wherein 3. The organic light emitting layer according to claim 1, wherein the organic light emitting layer comprises a coating film of an organic light emitting paint in which a polymer having an electron transporting property, a hole transporting property and a fluorescent property is dissolved in an organic solvent. Organic electroluminescence element. 4. The device according to claim 1, further comprising a hole transport layer interposed between said positive electrode layer and said organic light emitting layer.
The organic electroluminescence device according to claim 1. 5. The method according to claim 1, further comprising an electron transporting layer interposed between the organic light emitting layer and the negative electrode layer.
The organic electroluminescence device according to claim 1. 6. The method according to claim 1, wherein the hole transport layer is formed by an offset printing method,
Formed by at least one method selected from screen printing, gravure printing and spin coating,
5. The organic electroluminescence device according to claim 4, comprising a coating film of a hole transporting paint in which a hole transporting material and an electron accepting acceptor are dissolved in an organic solvent. 7. The method according to claim 1, wherein the electron transporting layer is formed by an offset printing method.
Formed by at least one method selected from screen printing, gravure printing and spin coating,
6. The organic electroluminescence device according to claim 5, comprising a coating film of an electron transporting paint in which an electron transporting material is dissolved in an organic solvent. 8. The organic light emitting layer has a thickness of 0.01 μm.
The organic electroluminescent device according to any one of claims 1 to 7, wherein the organic electroluminescent device is within a range of from 5 to 5 µm. 9. A metal, an alloy, or a material having a large work function on a substrate.
Forming a positive electrode layer comprising an electrically conductive compound and a mixture thereof, an organic luminescent paint in which an electron transporting material, a hole transporting material, a host polymer and a fluorescent dye are mixed and uniformly dissolved in an organic solvent, Alternatively, an organic light-emitting coating material in which a polymer having electron transporting property, hole transporting property and fluorescence property is dissolved in an organic solvent is prepared, and a coating film of the organic light-emitting coating material is formed on the positive electrode layer by offset printing. An organic light emitting layer is formed by heating and drying to form a negative electrode layer made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a small work function on the organic light emitting layer. A method for manufacturing an electroluminescence element. 10. A positive electrode layer comprising a metal, an alloy, an electrically conductive compound and a mixture thereof having a large work function is formed on a substrate, and a hole transporting material and an electron accepting acceptor are dissolved in an organic solvent. A hole transport paint is prepared, and a coating film of the hole transport paint is formed on the positive electrode layer by at least one method selected from offset printing, screen printing, gravure printing, and spin coating. To form a hole transport layer by heating and drying, and an organic light-emitting coating material in which an electron transport material, a hole transport material, a host polymer and a fluorescent dye are mixed and uniformly dissolved in an organic solvent, or an electron. Prepare an organic luminescent paint in which a polymer having transport properties, hole transport properties and fluorescent properties is dissolved in an organic solvent, and apply the organic luminescent paint on the hole transport layer by offset printing. Forming a film, heating and drying to form an organic light emitting layer, and forming a negative electrode layer made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a low work function on the organic light emitting layer. A method for producing an organic electroluminescence element. 11. A positive electrode layer comprising a metal, an alloy, an electrically conductive compound and a mixture thereof having a large work function is formed on a substrate, and an electron transporting material, a hole transporting material, a host polymer and a fluorescent dye are formed. An organic luminescent paint mixed and uniformly dissolved in an organic solvent, or an organic luminescent paint in which a polymer having electron transporting property, hole transporting property and fluorescent property is dissolved in an organic solvent is prepared, and the positive electrode layer is prepared. Form an organic light-emitting paint coating film by offset printing method, heat and dry to form an organic light-emitting layer, and prepare an electron-transport paint in which an electron-transport material is uniformly dissolved in an organic solvent. Forming a coating film of the electron transporting paint on the organic light emitting layer by at least one method selected from an offset printing method, a screen printing method, a gravure printing method, and a spin coating method, and heating. Forming an electron transport layer by drying and forming a negative electrode layer made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a low work function on the electron transport layer. Manufacturing method.