JP2003077657A - Coating liquid for forming organic led layer, donor film for organic led, manufacturing method for organic led display panel using the same, and organic led display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating liquid for forming an organic LED layer and a donor film for an organic LED capable of efficiently and uniformly forming the organic LED layer having satisfactory film formation property without causing cissing in a transfer process and provide a manufacturing method for an organic LED display panel and the organic LED display panel using the same. SOLUTION: This coating liquid for forming the organic LED layer of the donor film for the organic LED used when manufacturing the organic LED display panel is aqueous solution containing a light emitting material or an electric charge transport material and surface tensile force adjusting agent to realize the above purpose.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating liquid for forming an organic LED layer, a donor film for an organic LED, a method for manufacturing an organic LED display panel using the same, and an organic LED display panel.

[0002]

2. Description of the Related Art Conventionally, as a method for forming an organic LED display panel which does not require patterning of an organic LED layer, a vacuum vapor deposition method, a spin coating method, etc. have been proposed. In addition, as a method for forming an organic LED display panel that requires patterning of an organic LED layer such as a multi-color or full-color display panel, a mask vapor deposition method (for example, Japanese Patent Laid-Open No. 8-227276) or an inkjet method (for example, , Japanese Patent Laid-Open No. 10-12377).

However, the mask vapor deposition method has a problem that it is very difficult to manufacture an element using a large substrate, and the inkjet method has a problem that it takes a very long time to manufacture an element when a large substrate is used. It was Therefore, as a patterning method capable of using a large-sized substrate and significantly shortening the manufacturing time, a transfer method (for example, Japanese Patent Laid-Open Nos. 10-208881 and 1
JP-A 1-237504 and JP-A-11-26054.
No. 9) was proposed.

However, in the above-mentioned prior art, since an aqueous solution in which a polymer material is dissolved or dispersed is used as a coating liquid for forming a transfer layer such as a hole transport layer and a light emitting layer, these coating liquids are applied onto a base film. There is a problem in that “repellency” occurs when a donor film is formed by coating and a transfer layer having a good film-forming property cannot be formed. In the transfer using such a donor film, transfer unevenness occurs, a desired pixel pattern cannot be formed, and the obtained organic LE is obtained.
Light emission unevenness occurs in the D display panel.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an organic LED which does not cause "repellency" in the transfer process and has a good film-forming property.
It is an object of the present invention to provide a coating liquid for forming an organic LED layer and a donor film for an organic LED capable of efficiently and uniformly forming a layer, a method for manufacturing an organic LED display panel using the same, and an organic LED display panel. To do.

[0006]

Thus, according to the present invention, there is provided a coating liquid for forming an organic LED layer of a donor film for an organic LED used when manufacturing an organic LED display panel, wherein the coating liquid is A coating solution for forming an organic LED layer, which is an aqueous solution containing a light emitting material or a charge transporting material and a surface tension adjusting agent.

Further, according to the present invention, a single-layer or multi-layer transfer layer is laminated on a base film on which a light-heat conversion layer, optionally a heat propagation layer and / or a gas generating layer are laminated, At least one layer of the transfer layer is the above-mentioned organic LE.
Provided is a donor film for an organic LED, which is formed by a wet process using a coating liquid for forming a D layer.

Further, according to the present invention, when manufacturing an organic LED display panel comprising a substrate / first electrode / organic LED layer including at least a light emitting layer / second electrode, it is necessary to form it on or on the substrate. The above organic LED donor film is pasted on the above laminate so that the base film is on the outside, and then the donor film is irradiated with light or heat from the base film side to leave part or all of the transfer layer. A method for manufacturing an organic LED display panel is provided, which comprises peeling off the film to transfer the organic LED layer.

Further, according to the present invention, the above-mentioned organic LED
An organic LED display panel manufactured by the method of manufacturing a display panel is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The coating solution for forming an organic LED layer of the present invention is a coating solution for forming an organic LED layer of a donor film for an organic LED used in manufacturing an organic LED display panel, the coating solution comprising: The liquid is an aqueous solution containing a light emitting material or a charge transporting material and a surface tension adjusting agent.

The coating liquid for forming an organic LED layer of the present invention is a coating liquid for forming a light emitting layer containing a light emitting material and a surface tension adjusting agent and a coating liquid for a charge transport layer containing a charge transporting material and a surface tension adjusting agent. It can be roughly divided into liquids. Further, the charge transport layer coating liquid,
Depending on the type of charge transport material, a hole injection layer coating liquid containing a hole injection material, a hole transport layer coating liquid containing a hole transport material,
It can be roughly classified into an electron injection layer coating liquid containing an electron injection material and an electron transport layer coating liquid containing an electron transport material. Among these, the coating liquid for forming an organic LED layer of the present invention is preferably used as a coating liquid for a hole transport layer.

The surface tension adjusting agent commonly contained in the coating liquid for forming an organic LED layer of the present invention includes a surfactant and 2
A solvent having a surface tension of 60 mN / m or less at 0 ° C. may be mentioned.

The surfactant is preferably an ionic surfactant. Specific examples of the surfactant include amine oxide (manufactured by Kao Corporation, trade name: Amphitol 20).
N), Wako Pure Chemical Industries, Ltd., trade name: NCW, alkylbenzene sulfonate (manufactured by Lion Corporation, trade name: Lypon LH-500), silicone (Shin-Etsu Chemical Co., Ltd., Surfynol 104PA, 104E).
And so on.

Solvents having a surface tension of 60 mN / m or less at 20 ° C. include alcohols such as methanol, ethanol and isopropyl alcohol, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as methyl acetate and ethyl acetate, and methyl cellosolve. Examples thereof include cellosolve solvents such as acetate, hydrocarbon solvents such as hexane and octane, aromatic solvents such as benzene, toluene and xylene. Among these, alcohols and aromatic solvents are preferable, and alcohols are particularly preferable.

The content of the surface tension adjusting agent in the coating liquid for forming an organic LED layer of the present invention varies depending on the kind of the surface tension adjusting agent, but in the case of a surfactant, it is 0.01 to 50.
% By weight, preferably 0.1-10% by weight, 20 ° C.
In the case of a solvent having a surface tension of 60 mN / m or less,
0.01 to 50% by weight, preferably 0.1 to 10% by weight
Is.

The coating liquid for forming an organic LED layer of the present invention contains a surface tension adjusting agent so that the surface tension at 20 ° C. is 60 mN / m or less (preferably 30 mN / m).
The following), "repellency" does not occur in the transfer process,
A coating liquid for forming an organic LED layer, which can efficiently and uniformly form an organic LED layer having a good film-forming property, can be obtained.

Next, the coating liquid for forming the organic LED layer of the present invention will be described for each type.

The coating liquid for forming a light emitting layer is an aqueous solution in which one or more light emitting materials and the above surface tension adjusting agent are dissolved or dispersed in an aqueous solvent, and optionally a binder resin and a leveling agent. , A light emission assisting agent, a charge injection / transport material, an additive (donor, acceptor, etc.), a light emitting dopant, and the like. The respective materials are exemplified below, but these do not limit the present invention.

As the light emitting material, known light emitting materials for organic LEDs can be used. Such light emitting materials are classified into low molecular weight light emitting materials, polymer light emitting materials and precursors thereof, and specific compounds thereof are illustrated below, but the present invention is not limited thereto.

Examples of the low-molecular light emitting material include 4,
Aromatic dimethylidene compounds such as 4′-bis (2,2′-diphenylvinyl) -biphenyl (DPVBi), 5
-Oxadiazole compounds such as methyl-2- [2- [4- (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 3- (4-biphenylyl) -4-phenyl-5 -T-butylphenyl-1,
Triazole derivatives such as 2,4-triazole (TAZ), styrylbenzene compounds such as 1,4-bis (2-methylstyryl) benzene, thiopyrazine dioxide derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, diphenoquinone derivatives, fluorenone Examples include fluorescent organic materials such as derivatives, as well as fluorescent organometallic compounds such as azomethine zinc complex and (8-hydroxyquinolinato) aluminum complex (Alq ₃ ).

As the polymer light emitting material, for example, poly (2-decyloxy-1,4-phenylene) (DO-P
PP), poly [2,5-bis- [2- (N, N, N-triethylammonium) ethoxy] -1,4-phenyl-alto-1,4-phenylene] dibromide (PP
P-NEt ³⁺ ), poly [2- (2′-ethylhexyloxy) -5-methoxy-1,4-phenylenevinylene] (MEH-PPV), poly [5-methoxy- (2-
Propanoxysulfonide) -1,4-phenylenevinylene] (MPS-PPV), poly [2,5-bis- (hexyloxy) -1,4-phenylene- (1-cyanovinylene)] (CN-PPV) , Poly (9,9-dioctylfluorene) (PDAF), and the like.

Further, as the precursor of the polymer light emitting material,
For example, a poly (p-phenylene vinylene) precursor (Pr
e-PPV), poly (p-naphthalene vinylene) precursor (Pre-PNV), poly (p-phenylene) precursor (Pre-PPP), and the like.

Examples of the binder resin include polycarbonate and polyester, but the present invention is not limited thereto.

The aqueous solvent is not particularly limited as long as it can dissolve or disperse the above-mentioned luminescent material. Specifically, THF (tetrahydrofuran),
Examples thereof include aqueous solvents including solvents such as chloroform, toluene, xylene, trimethylbenzene.

The coating solution for forming a light emitting layer of the present invention is prepared by using each of the above components, and the solid content thereof is 0.01 to 2.
It is 0% by weight, preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight.

The viscosity (25 ° C.) of the coating solution for forming a light emitting layer of the present invention is preferably 100 cps or less, and 1 to 10
0 cps is more preferable, and 10 cps is particularly preferable. When the viscosity of the coating liquid exceeds 100 cps, a light emitting layer having a uniform film thickness cannot be obtained, which is not suitable for practical use, which is not preferable. The viscosity of the coating liquid can be appropriately adjusted depending on the amount of solid content and the like.

The coating liquid for forming the charge transport layer may be one kind or two kinds.
It is an aqueous solution in which one or more charge transport materials and the above surface tension adjusting agent are dissolved or dispersed in an aqueous solvent, and optionally contains a binder resin, a leveling agent, an additive (donor, acceptor, etc.) and the like. The respective materials are exemplified below, but these do not limit the present invention.

As the charge transport material, known charge transport materials for organic LEDs and organic photoconductors can be used. Such charge transport materials are classified into hole injection materials, hole transport materials, and electron transport materials, and specific compounds thereof are illustrated below, but the present invention is not limited thereto.

As the hole transport material, for example, an inorganic p-type semiconductor material; a porphyrin compound, N, N'-bis-
(3-methylphenyl) -N, N′-bis- (phenyl) -benzidine (TPD), N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine (NPD), etc. Low molecular weight materials such as aromatic tertiary amine compounds, hydrazone compounds, quinacridone compounds, styrylamine compounds; polyaniline (PANI), polyaniline-camphorsulfonic acid (PANI-CSA), 3,4
-Polymer material such as polyethylenedioxythiophene / polystyrene sulfonate (PEDOT / PSS), poly (triphenylamine derivative) (Poly-TPD), polyvinylcarbazole (PVCz); poly (p-
Phenylene vinylene) precursor (Pre-PPV), poly (p-naphthalene vinylene) precursor (Pre-PNV)
Examples thereof include precursors of polymer materials.

Examples of electron transport materials include inorganic n-type semiconductor materials; low molecular weight materials such as oxadiazole derivatives, triazole derivatives, thiopyrazine dioxide derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, diphenoquinone derivatives and fluorenone derivatives. ; Poly (oxadiazole) (Poly-OXZ)
Polymer materials such as Among the above charge transport materials, a hole transport material composed of a polythiophene derivative such as PEDOT / PSS or a polyaniline derivative such as PANI-CSA is preferable.

Examples of the binder resin include polycarbonate and polyester, but the present invention is not limited thereto.

The aqueous solvent is not particularly limited as long as it can dissolve or disperse the above charge transport material. Specifically, an aqueous solvent containing a solvent such as THF (tetrahydrofuran), chloroform, toluene, xylene, and trimethylbenzene can be used.

The coating liquid for forming the charge transport layer of the present invention is prepared by using each of the above components, and the solid content thereof is preferably 0.01 to 20% by weight, more preferably 0.1 to 10%.
%, More preferably 1 to 5% by weight.

Further, the viscosity (25 ° C.) of the coating liquid for forming the charge transport layer of the present invention is preferably 100 cps or less, and 1 to 1
00 cps is more preferable, and 10 cps is particularly preferable. When the viscosity of the coating liquid exceeds 100 cps,
A charge transport layer having a uniform thickness cannot be obtained, which is not suitable for practical use, which is not preferable. The viscosity of the coating liquid can be appropriately adjusted depending on the amount of solid content and the like.

The organic LED donor film of the present invention comprises:
A single-layer or multi-layer transfer layer is laminated on a base film on which a light-heat conversion layer, and optionally a heat propagation layer and / or a gas generating layer are laminated, and at least one layer of the transfer layer is the above organic layer. It is characterized by being formed by a wet process using an LED layer forming coating liquid.

The organic LED donor film of the present invention comprises:
Depending on the type of transfer layer, a donor film for forming a light emitting layer,
It is also referred to as a donor film for forming a charge transport layer (a donor film for forming a hole injection layer, a donor film for forming a hole transport layer, a donor film for forming an electron injection layer and a donor film for forming an electron transport layer) and the like.

Next, each component of the organic LED donor film of the present invention will be described.

The base film 6 is one in which at least the light-heat conversion layer 2 is formed on the base film 1 (see FIG. 1 (a)). Further, if necessary, the light-heat conversion layer 2
The heat propagation layer 4 may be formed thereon (see FIG. 1B), and the gas generation layer 5 may be further formed (see FIG. 1C).

(1. Base film) The base film is a transparent polymer film. Examples thereof include polycarbonate (PC), polyethylene terephthalate (PET), polyester, polyacryl, epoxy resin, polyethylene, polystyrene, and polyether sulfone, but the present invention is not limited thereto. Among these, PC and PET are particularly preferable. The thickness of the base film is preferably 10 to 600 μm, particularly preferably 50 to 200 μm.

(2. Light-heat conversion layer) The light-heat conversion layer (also referred to as "light absorption layer") is composed of a substance having a property of absorbing light and efficiently generating heat. For example, a metal film made of aluminum, an oxide thereof and / or a sulfide thereof, an organic film in which carbon black, graphite or an infrared dye is dispersed in a polymer material (for example, thermosetting epoxy resin). The invention is not limited to these.

The metal film can be formed by a known method such as a vacuum vapor deposition method, an electron beam vapor deposition method and a sputtering method. The film thickness thereof is preferably 50 to 10,000 Å, particularly 100 to 5,000 Å. preferable. The organic film can be formed by a known coating method, and the film thickness thereof is preferably 0.01 to 50 μm,
1 to 10 μm is particularly preferable.

(3. Heat Propagation Layer) The heat propagation layer (also referred to as “peeling layer”) is a layer that propagates heat for efficient transfer. For example, a polymer material such as poly-α-methylstyrene can be used, but the present invention is not limited thereto. The heat propagation layer can be formed by a known film forming method, and the film thickness thereof is preferably 0.001 to 10 μm, particularly preferably 0.005 to 5 μm.

(4. Gas Generation Layer) The gas generation layer causes a decomposition reaction upon absorption of light or heat, releases nitrogen gas or hydrogen gas, for example, and provides energy for transfer, that is, transfer. It is a layer that contributes to improved efficiency. Examples of the material forming the gas generating layer include pentaerythritol tetranitrate and trinitrotoluene, but the present invention is not limited thereto. The gas generating layer can be formed by a known film forming method, and the film thickness thereof is preferably 0.001 to 10 μm,
0.005 to 5 μm is particularly preferable.

(5. Transfer Layer) The transfer layer is a layer that is actually transferred in the transfer step, and may have a structure of only an organic LED layer or a structure of a combination of an electrode layer and an organic LED layer. Specific examples include the following configurations, but the present invention is not limited thereto. (1) Organic LED layer (2) First electrode / organic LED layer (3) Organic LED layer / second electrode (4) First electrode / organic LED layer / second electrode The stacking order of the transfer layer on the base film Is not limited.

(5-1. Organic LED Layer) The organic LED layer may have a single-layer structure or a multi-layer structure. Specifically, the following constitutions are mentioned, but the present invention is not limited thereto. . Hole transport layer / light emitting layer hole transport layer / light emitting layer / electron transport layer hole injection layer / hole transport layer / light emitting layer / electron transport layer wherein a light emitting layer, a hole injection layer, a hole transport layer and Each layer of the electron transport layer may have a single-layer structure or a multi-layer structure.

The organic LED donor film of the present invention comprises:
Organic LED layers such as a light emitting layer, a hole transporting layer, an electron transporting layer and a hole injecting layer to be a transfer layer are formed by a known wet process using the coating liquid for forming an organic LED layer of the present invention (film formation). ) It has been done. As the wet process, spin coating method, dip coating method, doctor blade method,
Coating methods such as discharge coating method, spray coating method, inkjet method, letterpress printing method, intaglio printing method, screen printing method, printing method such as microgravure coating method, etc. are mentioned. Among them, film thickness uniformity and material utilization From the point of efficiency,
The microgravure coating method is preferable.

When the organic LED layer serving as the transfer layer has a multi-layer structure, at least one layer may be formed by a known wet process using the coating liquid for forming an organic LED layer of the present invention, and other layers. The organic LED layer is formed by a known dry process such as a vacuum vapor deposition method, an EB method, an MBE method, a sputtering method or an OVPD method using a material obtained by removing the solvent from the coating liquid for forming the organic LED layer of the present invention. Membrane).

The thickness of each of the above organic LED layers is usually 1 to
It is about 1000 nm. The environment for forming the organic LED layer is not particularly limited, but from the viewpoint of preventing moisture absorption of the formed film and deterioration of the used organic material, it is preferable to carry out in an inert gas or in a vacuum. . Further, after forming the organic LED layer by the wet process, it is preferable to perform heat drying for the purpose of removing the residual solvent. The environment for heating and drying is not particularly limited, but from the viewpoint of preventing the deterioration of the organic material used, it is preferably carried out in an inert gas, preferably under reduced pressure.

2 and 3 are schematic cross-sectional views showing a process of forming an organic LED layer on a base film in the production of the organic LED donor film of the present invention. In these figures, the organic LED layer is formed on the base film 6 by the microgravure method. In addition, in FIG. 3, two organic LED layers are continuously formed. In the figure, 6 is a base film, 8 is a roll, 9 is a microgravure roll, 10 is a dryer, and 11 is a cooler.

(5-2. First Electrode and Second Electrode) First
A known electrode material can be used as the electrode material forming the electrode and the second electrode. As an electrode material for forming the anode, metals having a high work function (Au, Pt, Ni
Etc.) and transparent electrode materials (ITO, IDIXO, Sn)
O ₂ etc.) and the like. Further, the electrode material forming the cathode contains at least a metal having a low work function (Ca, Ce, Cs, Ba, Al, Mg: Ag: Ag).
Alloy, Li: Al alloy) and a combination of a thin insulating layer and a metal electrode (LiF / Al, Li ₂ O / A)
1, LiF / Ba / Al, etc.) and the like. Each electrode can be formed using these materials by a known method such as an EB method, a sputtering method, or a resistance heating vapor deposition method, but the present invention is not limited to these. The film thickness is usually about 0.5 to 1000 nm. Also,
The formed electrode can be patterned by the photolithography method.

FIG. 1 is a partial schematic sectional view of the donor film of the present invention. (A) is a donor film 7 composed of a base film 6 composed of a base film 1 and a light-heat conversion layer 2 and a transfer layer 3, and (b) is a base film 1 and a light-heat conversion layer 2. A donor film 7 composed of a base film 6 composed of a heat propagation layer 4 and a transfer layer 3, (c) consisting of a base film 1, a light-heat conversion layer 2, a heat propagation layer 4 and a gas generation layer 5. The donor film 7 is composed of the base film 6 and the transfer layer 3.

The method of manufacturing an organic LED display panel according to the present invention comprises a substrate / first electrode / organic LE including at least a light emitting layer.
In manufacturing an organic LED display panel composed of a D layer / second electrode, the above organic L is placed on a substrate or a required laminate formed on the substrate so that the base film is on the outside.
An ED donor film is attached, then light or heat is radiated from the base film side, and the donor film is peeled off leaving part or all of the transfer layer, and the organic L
It is characterized in that the ED layer is transferred and formed.

In the organic LED display panel, basically, a plurality of organic LED elements each having a first electrode, an organic LED layer having at least one light emitting layer (organic layer) and a second electrode sequentially stacked are arranged as one pixel. It is manufactured by (patterning).

Next, referring to FIG. 4, the organic LED of the present invention
The method for manufacturing the display panel will be specifically described, but the present invention is not limited thereto.

In FIG. 4, the base film 6 on which the transfer layer 3 is formed (the donor film for an organic LED of the present invention) and the substrate 12 on which the first electrode 15 is formed are outside the base film 6 and the substrate 12. Then, the base film side (base film side of the base film) is irradiated with light (for example, laser light) or heat is radiated.
Next, the transfer is completed by peeling off the donor film while leaving part or all of the transfer layer 3. After that, the substrate 12 is preferably vacuum dried or heat dried, and the series of transfer steps is preferably performed in an inert gas in consideration of moisture absorption of the forming layer (film) and alteration of the material.

The transfer layer may have a single layer structure or a multilayer structure as described above. When the transfer layer has a multilayer structure including all the constituent layers of the organic LED element, the transfer process is completed once, but the transfer layer has a single layer or a multilayer structure including a part of the constituent layers of the organic LED element. In some cases, the above transfer step may be repeated. That is, as the transfer layer, organic layers having different properties are formed on different base films, and the transfer process may be repeated to form a multilayer film of the organic layers on the substrate.

The organic LED panel may be manufactured by combining the transfer method using the donor film for an organic LED of the present invention and a known dry process and / or wet process. As a known dry process,
Examples of the known wet process include a vacuum vapor deposition method, an EB method, an MBE method, and a sputtering method. Spin coating methods, dip coating methods, doctor blade methods, discharge coating methods, spray coating methods, and other coating methods, and inkjet methods. Printing methods such as a relief printing method, an intaglio printing method, a screen printing method, and a microgravure coating method.

As the above transfer layer, for example, an organic red light emitting multilayer film including a hole transporting layer / red light emitting layer, an organic green light emitting multilayer film including a hole transporting layer / green light emitting layer, and a hole transporting layer. / Obtaining an organic LED display panel having red, green and blue light emitting multilayer films by repeating a transfer process on a substrate using three kinds of donor films having an organic blue light emitting multilayer film composed of a blue light emitting layer. You can

When each electrode is formed by the transfer method using the donor film having the first electrode or the second electrode, each electrode may not be formed after the transfer step, but the transferred first electrode is formed. Alternatively, a metal film may be further formed on the second electrode to serve as the first electrode or the second electrode.

Examples of the substrate used in the present invention include inorganic materials such as glass and quartz; plastics such as polyethylene terephthalate (PET); insulating substrates such as ceramics such as alumina; metal substrates such as aluminum and iron and SiO. _2. A substrate coated with an insulating material such as an organic insulating material; a substrate obtained by subjecting the surface of a metal substrate such as aluminum to an insulating treatment by a method such as anodic oxidation can be mentioned, but the present invention is not limited thereto. Absent.

Further, a switching element such as a thin film transistor and / or a partition may be formed on the substrate. Polysilicon TFT formed by low temperature process
In order to form a thin film transistor using
A substrate that does not melt at a temperature of ℃ or less and does not cause distortion is preferable. Also, the polysilicon T formed by the high temperature process
To form a thin film transistor using FT, 1
A substrate that does not melt at a temperature of 000 ° C. or lower and does not cause distortion is preferable.

FIG. 5 is a schematic view showing an example of a transfer step in the method for manufacturing an organic LED display panel of the present invention.
In FIG. 5, a transfer layer (not shown) formed on the donor film 7 wound around the roll 13 is transferred onto the substrate 12 by light or heat 14. Here, the donor film is continuously peeled off by winding the film. The same transfer process is repeated three times by moving the substrate 12 from left to right. Thereby, for example, red, green, and blue light emitting pixels can be formed in the same process.

6A to 6J show the organic L of the present invention.
It is a schematic process drawing which shows an example of the other transfer process in the manufacturing method of an ED display panel. In this step, first, (a)
On the substrate 12 on which the first electrode 15 and the partition 16 are formed, the base film 6 (donor film for organic LED) on which the red light emitting layer 17 is formed as a transfer layer is attached so that the base film 6 is on the outside. (B) Next, light or heat is radiated from the base film side (Fig. 1
4), (c) The donor film is peeled off leaving a part or all of the transfer layer, and the red light emitting layer is transferred and formed as the organic LED layer. Subsequently, using the base film on which the green light emitting layer 18 is formed and the base film on which the blue light emitting layer 19 is formed, respectively, in the same manner as in steps (a) to (c), steps (d) to (f) and Step (g) ~
In (i), the green light emitting layer and the blue light emitting layer are transferred and formed.
(J) Next, the second electrode 20 is formed on the entire surface of each of the transferred light emitting layers by a known method.

In the organic LED display panel of the present invention, it is preferable to provide a polarizing plate on the electrode on the side where the emitted light is taken out. As the polarizing plate used, a conventional linear polarizing plate and 1
A combination of / 4λ plates is preferable. This allows
The contrast as an organic LED element can be improved.

In the organic LED display panel of the present invention, it is preferable to provide a sealing film and a sealing substrate on the electrode from which light is emitted. The sealing film or the sealing substrate used is preferably one formed by using a known sealing material and sealing method. Specific examples include a method of sealing an inert gas such as nitrogen gas and argon gas with glass, a metal, and the like, and a method of mixing a hygroscopic agent such as barium oxide into the inert gas. Is not limited to these. Alternatively, a resin may be directly spin-coated or attached on the counter electrode to form a sealing film. By this sealing film, it is possible to prevent oxygen and water from mixing into the element from the outside, and the life of the element is improved.

According to the present invention, there is provided an organic LED display panel manufactured by the above manufacturing method. As the driving method, a conventional organic LED display panel driving method such as passive matrix driving or active matrix driving can be used, and the present invention is not limited to these.

[0067]

EXAMPLES The present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited to these Examples. The surface tension of the coating liquids obtained in Examples and Comparative Examples at 20 ° C. was measured using a surface tension measuring device (Kyowa Interface Science Co., Ltd., model: CA-A) (unit: mN / m). The viscosities of the coating solutions obtained in Examples and Comparative Examples at 25 ° C. were measured using a viscometer (manufactured by Fungilab, model: Visco Basic) (unit: cps).

(Comparative Example 1) A substrate film having a thickness of 0.
A 1 mm polyethylene terephthalate (PET) film was used, and a thermosetting epoxy resin mixed with carbon particles was formed on the film as a light-heat conversion layer to a film thickness of 5 μm.
The coating was carried out so as to have a thickness of m. Then, a poly-α-methylstyrene film was formed as a heat propagation layer (release layer) on the coating film so as to have a thickness of 1 μm to obtain a base film.

Next, a transfer layer having a film thickness of 50 nm to be a hole transport layer was formed on the base film by using a hole transport layer forming coating liquid by a spin coater. Here, as the coating liquid for forming the hole transport layer, 3,4-polyethylenedioxythiophene / polystyrene sulfonate (PEDOT) is used.
/ PSS) dissolved in pure water at a solid content of 1 wt% was used. The surface tension and viscosity of this coating liquid for forming a hole transport layer were 63.8 mN / m and 8.4 cps. In addition, it was observed with an optical microscope whether or not "repellency" was present on the base film on which the transfer layer was formed. The results of the observation are shown in Table 1 together with the presence or absence of "repellency" together with the surface tension of the coating liquid for forming the hole transport layer used.

Example 1 A base film was obtained in the same manner as in Comparative Example 1 except that 10% by weight of methanol was added as a surface tension adjusting agent to the hole transport layer forming coating liquid.
evaluated. The results obtained are shown in Table 1.

Example 2 A base film was obtained in the same manner as in Comparative Example 1 except that 50% by weight of methanol was added as a surface tension adjusting agent to the coating liquid for forming the hole transport layer.
evaluated. The results obtained are shown in Table 1.

Example 3 A base film was obtained in the same manner as in Comparative Example 1 except that 50 wt% of ethanol was added as a surface tension adjusting agent to the hole transport layer forming coating liquid.
evaluated. The results obtained are shown in Table 1.

Example 4 Surfactant Surfynol 104 was used as a surface tension adjusting agent in the hole transport layer forming coating liquid.
A base film was obtained and evaluated in the same manner as in Comparative Example 1 except that 0.1% by weight of PA (manufactured by Shin-Etsu Chemical Co., Ltd.) was added. The results obtained are shown in Table 1.

(Example 5) Surfactant Surfynol 104 was used as a surface tension adjusting agent in the coating liquid for forming the hole transport layer.
A base film was obtained and evaluated in the same manner as in Comparative Example 1 except that 0.1% by weight of E (manufactured by Shin-Etsu Chemical Co., Ltd.) was added. The results obtained are shown in Table 1.

(Comparative Example 2) A substrate film having a thickness of 0.
A 1 mm PET film is used, and light is applied onto this film.
As the heat conversion layer, a thermosetting epoxy resin mixed with carbon particles was coated to a film thickness of 5 μm and cured at room temperature. Then, a poly-α-methylstyrene film was formed as a heat propagation layer (release layer) on the coating film so as to have a thickness of 1 μm to obtain a base film.

Then, a transfer layer having a film thickness of 50 nm to be a hole transport layer was formed on the base film by using a hole transport layer forming coating liquid by a spin coater. Here, as the hole transport layer forming coating solution, a solution obtained by dissolving polyaniline-camphor sulfonic acid (PANI-CSA) in pure water at a solid content of 1 wt% was used. The viscosity of the coating liquid for forming the hole transport layer was 67.6 mN / m and 6.4 cps. The obtained base film was evaluated in the same manner as in Comparative Example 1. The results obtained are shown in Table 1.

Example 6 A base film was obtained in the same manner as in Comparative Example 2 except that 10% by weight of methanol was added as a surface tension adjusting agent to the hole transport layer forming coating liquid.
evaluated. The results obtained are shown in Table 1.

Example 7 A base film was obtained in the same manner as in Comparative Example 2 except that 50% by weight of methanol was added as a surface tension adjusting agent to the hole transport layer forming coating liquid.
evaluated. The results obtained are shown in Table 1.

Example 8 A base film was obtained in the same manner as in Comparative Example 2 except that 50% by weight of ethanol was added as a surface tension adjusting agent to the coating liquid for forming the hole transport layer.
evaluated. The results obtained are shown in Table 1.

Example 9 Surfactant Lipon LH-500 was used as a surface tension adjusting agent in the hole transport layer forming coating liquid.
A base film was obtained and evaluated in the same manner as in Comparative Example 2 except that 0.1% by weight (manufactured by Lion Corporation) was added. The results obtained are shown in Table 1.

(Example 10) Surfactant Anhitol 20N was used as a surface tension adjusting agent in the hole transport layer forming coating liquid.
A base film was obtained and evaluated in the same manner as in Comparative Example 2 except that 0.1% by weight (manufactured by Kao Corporation) was added. The results obtained are shown in Table 1.

[0082]

[Table 1]

From the results shown in Table 1, when the surface tension adjusting agent was added to the hole transport layer forming coating liquid, the surface tension was 60 m.
It can be seen that N / m or less, the "repellency" does not occur in the transfer layer serving as the hole transport layer, and the transfer layer can be formed efficiently and uniformly on the base film.

Example 11 (Production of TFT Substrate) On a glass substrate, α-Si having a film thickness of 50 nm was formed by LP-CVD method by decomposition of Si ₂ H _6.
A film was formed, and then α-Si was polycrystallized by an excimer laser annealing method. Next, the Poly-Si film including the channel portion and the source / drain portions is etched to form Poly-Si as a gate insulating film at 1000 ° C.
As described above, thermal oxidation was performed to form SiO ₂ having a film thickness of 50 nm. After that, Al having a film thickness of 100 nm was formed as a gate electrode by sputtering. Then, the gate electrode was patterned. Also, the lower electrode of the capacitor was processed. After that, the side surface of the gate electrode was anodized to form an offset portion, and then the source / drain portion was doped with phosphorus at a high concentration by an ion doping method. A scan line was formed, and thereafter, source / drain metal and a common electrode were further formed. Then, an upper electrode of the capacitor was formed, and a Poly-Si TFT was formed by a low temperature process.

Then, a SiO 2 film having a thickness of 3 μm is formed as a flattening film.
_Two films were formed. Next, a resist was applied on the flattening film, and a pattern was formed by penetrating the contact hole portion by a photolithography method, and then the contact hole was opened by etching to wash away the resist.
Next, an aluminum film having a thickness of 4 μm was formed on the insulating film by a sputtering method. Next, by polishing this, aluminum formed on the insulating film was removed, and at the same time, the insulating film and the connection wiring in the contact hole were flattened.

Then, a 150 nm-thickness aluminum film was formed on the flattened film by a sputtering method so as to be electrically connected to the drain electrode through a contact hole. Then, it etched and it was set as the pixel electrode. The film-formed transparent electrode has a surface resistance of <10 Ω / □ and a transmittance of> 87.
% (550 nm) and flatness ± 2%. Next, the pixel electrode was patterned into a predetermined shape by a photolithography method. Next, as an insulating film, S having a thickness of 200 nm is formed.
A film of iO ₂ was formed. A resist was applied thereon and patterned into a predetermined shape. Next, SiO ₂ was etched by dry etching so as to form a taper between the pixels, and an insulating film was formed between the pixels. As a result, it is possible to prevent deterioration of the element due to electric field concentration at the edge portion of the pixel electrode. Also, by making it tapered,
When the organic LED layer is formed by the transfer method, the donor film (the organic LED layer that is the transfer layer) completely adheres to the substrate, and thus it is possible to prevent the non-transferred portion of the organic LED layer from occurring.

In order to prevent the deterioration of the organic layer and the electrode, the following steps from the production of the donor film for forming each of the red, green and blue light emitting pixels to the pattern transfer of them and the formation of the counter electrode and the sealing film are performed. It was carried out in an inert gas or in vacuum.

(Preparation of Donor Film for Forming Red Light Emitting Pixels) A PET film having a thickness of 0.1 mm was used as a base film, and a thermosetting epoxy resin containing carbon particles as a light-heat conversion layer was formed on this film. The film thickness is 5μ
The coating was carried out so as to have a thickness of m. Then, a poly-α-methylstyrene film was formed as a heat propagation layer (release layer) on the coating film so as to have a thickness of 1 μm to obtain a base film.

Then, a transfer layer having a film thickness of 50 nm to be a hole transport layer was formed on the base film using the hole transport layer forming coating solution used in Example 3 with a microgravure coater. Next, this film was heated at 110 ° C. for 5 minutes in a high-purity nitrogen atmosphere to remove the solvent in the transfer layer.

Then, a transfer layer having a film thickness of 75 nm to be a red light emitting layer was formed on the hole transporting layer using a coating liquid for forming a red light emitting layer with a microgravure coater. Here, as the coating liquid for forming the red light emitting layer, poly [2,5-bis-
(Hexyloxy) -1,4-phenylene- (1-cyanovinylene)] (CN-PPV) dissolved in chloroform at a solid content of 2 wt% was used. The surface tension of the coating liquid at this time was 16.7 mN / m, and the viscosity was 2.6 c.
It was ps. Next, this film was heated at 110 ° C. for 5 minutes in a high-purity nitrogen atmosphere to remove the solvent in the transfer layer to obtain a red-light-emitting pixel forming donor film.

(Preparation of Donor Film for Forming Green Light-Emitting Pixels) A PET film having a thickness of 0.1 mm was used as a base film, and a thermosetting epoxy resin containing carbon particles as a light-heat conversion layer on this film. The film thickness is 5μ
The coating was carried out so as to have a thickness of m. Then, a poly-α-methylstyrene film was formed as a heat propagation layer (release layer) on the coating film so as to have a thickness of 1 μm to obtain a base film.

Then, a transfer layer having a film thickness of 50 nm to be a hole transport layer was formed on the base film by using the hole transport layer forming coating solution used in Example 3 with a microgravure coater. Next, this film was heated at 110 ° C. for 5 minutes in a high-purity nitrogen atmosphere to remove the solvent in the transfer layer.

Then, a transfer layer having a film thickness of 75 nm to be a green light emitting layer was formed on the hole transport layer by using a coating solution for forming a green light emitting layer with a microgravure coater. Here, as the green light emitting layer forming coating solution, a solution obtained by dissolving a poly (p-phenylene vinylene) precursor (Pre-PPV) in methanol at a solid content of 2 wt% was used. The surface tension of the coating liquid at this time was 17.2 mN / m and the viscosity was 3.6 c.
It was ps. Next, this film was heated at 110 ° C. for 5 minutes in a high-purity nitrogen atmosphere to remove the solvent in the transfer layer and at the same time convert Pre-PPV into PPV to obtain a green light emitting pixel forming donor film. .

(Preparation of Donor Film for Forming Blue Light Emitting Pixels) A PET film having a thickness of 0.1 mm was used as a base film, and a thermosetting epoxy resin in which carbon particles were mixed as a light-heat conversion layer on this film. The film thickness is 5μ
The coating was carried out so as to have a thickness of m. Then, a poly-α-methylstyrene film was formed as a heat propagation layer (release layer) on the coating film so as to have a thickness of 1 μm to obtain a base film.

Then, using the coating liquid for forming a hole transport layer used in Example 3, a transfer layer having a film thickness of 50 nm to be a hole transport layer was formed on the base film using a microgravure coater. Next, this film was heated at 110 ° C. for 5 minutes in a high-purity nitrogen atmosphere to remove the solvent in the transfer layer.

Then, a transfer layer having a film thickness of 75 nm to be a blue light emitting layer was formed on the hole transporting layer by using a blue light emitting layer forming coating liquid with a microgravure coater. Here, as the coating liquid for forming the blue light emitting layer, poly (9,9-dioctylfluorene) (PDAF) was added to xylene at a solid content of 1 wt.
The thing melt | dissolved in% was used. The surface tension of the coating liquid at this time was 17.8 mN / m, and the viscosity was 6.6 cps. Next, this film was heated at 110 ° C. for 5 minutes in a high-purity nitrogen atmosphere to remove the solvent in the transfer layer to obtain a blue light-emitting pixel forming donor film.

(Patterning Transfer) A red light emitting pixel forming donor film is attached to a substrate on which a p-Si TFT is formed, a 13 W YAG laser is scanned at a desired position, the base film is peeled off, and p- The hole transport layer and the red light emitting layer (red light emitting pixel) in the donor film for forming a red light emitting pixel were pattern-transferred onto the substrate on which the Si TFT was formed. Next, using the donor film for forming a green light emitting pixel and the donor film for forming a blue light emitting pixel, pattern transfer of the green light emitting pixel and the blue light emitting pixel to the substrate on which the p-Si TFT is formed in the same manner as the red light emitting pixel. did.

(Formation of Counter Electrode and Sealing Film) The substrate on which each light emitting pixel was formed was heated in vacuum at 100 ° C. for 30 minutes to completely remove water adsorbed in the organic film. Next, while maintaining the above vacuum state, the substrate was fixed in a metal vapor deposition chamber, and a transparent conductive film (Idemitsu Kosan Co., Ltd.) was formed by a sputtering method at room temperature so as to have a film thickness of 150 nm as a counter electrode (transparent electrode). Product name: IDIX
O) was formed on the entire surface. An epoxy resin film was formed as a sealing film so as to have a film thickness of 1 μm on the entire surface of the counter electrode by a spin coating method to complete an organic LED display panel.

When the completed organic LED display panel was connected to a driving circuit, a signal line was connected to a power source, and scanning signals were sequentially input to scanning lines, light emission without emission unevenness was observed from all pixels.

[0100]

According to the present invention, the transfer layer of the base film used when manufacturing the organic LED display panel by the transfer method can be formed efficiently and uniformly. Further, since the obtained transfer layer has a good film-forming property, it is possible to manufacture an organic LED display panel without uneven light emission.

[Brief description of drawings]

FIG. 1 is a partial schematic cross-sectional view of a donor film for an organic LED of the present invention.

FIG. 2 is a schematic cross-sectional view showing a process of forming an organic LED layer on a base film in the production of the organic LED donor film of the present invention.

FIG. 3 is a schematic cross-sectional view showing another film forming process of the organic LED layer on the base film in the production of the organic LED donor film of the present invention.

FIG. 4 is a schematic cross-sectional view showing a method for manufacturing an organic LED display panel of the present invention.

FIG. 5 is a schematic view showing an example of a transfer step in the method for manufacturing an organic LED display panel of the present invention.

FIG. 6 is a schematic process drawing showing an example of another transfer process in the method for manufacturing an organic LED display panel of the present invention.

[Explanation of symbols]

1 Base film 2 Light-heat conversion layer 3 Transfer layer 4 Heat transfer layer 5 Gas generation layer 6 base film 7 Donor film 8, 13 rolls 9 Micro gravure roll 10 dryer 11 cooling machine 12 substrates 13 rolls 14 Light (laser) or heat 15 First electrode 16 partitions 17 Red light emitting layer 18 Green light emitting layer 19 Blue light emitting layer 20 Second electrode

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/22 H05B 33/22 DF Term (reference) 3K007 AB04 AB15 AB17 AB18 BA06 CA01 CB01 DA01 DB03 EB00 FA01 5C094 AA03 AA08 AA43 AA48 BA03 BA12 BA27 CA19 CA24 DA13 EA04 EA05 EB02 FA01 FA02 FB01 FB20 GB10 JA20 5G435 AA04 AA17 BB05 CC09 CC12 HH01 HH18 HH20 KK05 KK10

Claims (8)

[Claims] 1. A coating liquid for forming an organic LED layer of a donor film for an organic LED used in manufacturing an organic LED display panel, wherein the coating liquid is a light emitting material or a charge transporting material and a surface tension adjusting agent. A coating liquid for forming an organic LED layer, which is an aqueous solution containing. 2. The coating liquid for forming an organic LED layer according to claim 1, wherein the coating liquid for forming an organic LED layer has a surface tension at 20 ° C. of 60 mN / m or less. 3. The surface tension adjusting agent is a surfactant or 2
The coating liquid for forming an organic LED layer according to claim 1 or 2, which is a solvent having a surface tension of 60 mN / m or less at 0 ° C. 4. The coating liquid for forming an organic LED layer according to claim 3, wherein the solvent having a surface tension of 60 mN / m or less at 20 ° C. is an alcohol selected from methanol, ethanol and isopropyl alcohol. 5. The coating liquid for forming an organic LED layer according to claim 1, wherein the charge transport material is a hole transport material composed of a polythiophene derivative or a polyaniline derivative. 6. A light-to-heat conversion layer, optionally a heat propagation layer and / or
Alternatively, a single-layer or multi-layer transfer layer is laminated on a base film on which a gas generating layer is laminated, and at least one layer of the transfer layer is the organic LED layer according to any one of claims 1 to 5. A donor film for an organic LED, which is formed by a wet process using a forming coating liquid. 7. In manufacturing an organic LED display panel comprising a substrate / first electrode / organic LED layer including at least a light emitting layer / second electrode, on a substrate or a required laminate formed on the substrate, The donor film for an organic LED according to claim 6 is attached so that the base film is on the outside, and then the donor film is irradiated with light or heat from the base film side to leave a part or all of the transfer layer. A method for manufacturing an organic LED display panel, which comprises peeling and transferring the organic LED layer. 8. An organic LED display panel manufactured by the method for manufacturing an organic LED display panel according to claim 7.