WO2010018734A1

WO2010018734A1 - Transparent electrode, organic electroluminescent element, and method for producing transparent electrode

Info

Publication number: WO2010018734A1
Application number: PCT/JP2009/062876
Authority: WO
Inventors: 昌紀後藤; 博和小山
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2008-08-11
Filing date: 2009-07-16
Publication date: 2010-02-18
Also published as: JPWO2010018734A1; JP5397377B2

Abstract

Disclosed are a transparent electrode having excellent conductivity, excellent transparency and high smoothness, a method for producing the transparent electrode, and an organic electroluminescent element using the transparent electrode. The transparent electrode has a patterned conductive part and a non-patterned part on a transparent support, and is characterized in that the conductive part contains a metal nanowire and a conductive polymer, or alternatively a metal nanowire and a metal oxide, that the non-patterned part contains a resin, that the surface of the conductive part has an arithmetic average roughness Ra of not more than 5 nm and a maximum height Rz of not more than 50 nm, and that the maximum difference in height between the conductive part and the non-patterned part is not more than 50 nm.

Description

Transparent electrode, organic electroluminescence element, and method for producing transparent electrode

The present invention relates to a transparent electrode having excellent conductivity and transparency and high smoothness, a method for producing the same, and an organic electroluminescence device using the transparent electrode.

In recent years, various types of display technologies such as liquid crystal, plasma, organic electroluminescence, field emission, etc. have been developed in response to increasing demand for thin TVs. In any of these displays having different display methods, the transparent electrode is an essential constituent technology. In addition to televisions, transparent electrodes are an indispensable technical element in touch panels, mobile phones, electronic paper, various solar cells, and various electroluminescence light control elements.

Conventionally, as transparent electrodes, various metal thin films such as Au, Ag, Pt, Cu, indium oxide doped with tin or zinc (ITO, IZO), zinc oxide doped with aluminum or gallium (AZO, GZO), fluorine, Metal oxide thin films such as tin oxide (FTO, ATO) doped with antimony, conductive nitride thin films such as TiN, ZrN, and HfN, and conductive boride thin films such as LaB ₆ are known and combinations thereof. Various electrodes such as Bi ₂ O ₃ / Au / Bi ₂ O ₃ and TiO ₂ / Ag / TiO ₂ are also known. In addition to inorganic materials, transparent electrodes using CNTs (carbon nanotubes) and conductive polymers have also been proposed (see, for example, Non-Patent Document 1).

However, since the metal thin film, nitride thin film, boron thin film and conductive polymer thin film described above cannot have both light transmission properties and conductive properties, special technical fields such as electromagnetic shielding and the like are relatively high. It was used only in the touch panel field where resistance values are allowed.

On the other hand, metal oxide thin films are becoming mainstream of transparent electrodes because they can achieve both light transmittance and conductivity and are excellent in durability. In particular, ITO is widely used as a transparent electrode for various optoelectronics because it has a good balance between light transmittance and conductivity and it is easy to form an electrode fine pattern by wet etching using an acid solution. However, the above oxide conductor represented by ITO or the like forms a transparent conductive film on the surface of the substrate by a vacuum process such as sputtering or a liquid phase method such as sol-gel. In order to form a transparent conductive film by a vacuum process such as sputtering, expensive equipment is required. On the other hand, in the liquid phase method, high temperature treatment at 500 ° C. or higher is necessary to obtain high conductivity.

Other transparent electrodes include transparent electrodes in which a mesh structure is formed by a metal pattern typified by an electromagnetic wave shielding film of a plasma display (see, for example, Patent Documents 1 and 2), and a fine mesh using metal nanowires The transparent electrode which consists of is disclosed (for example, refer patent document 3). In particular, in a metal mesh using silver, both good conductivity and transparency can be achieved due to the inherent high conductivity of silver.

However, although the metal mesh portion has high conductivity, there is a defect that the portion that transmits light does not have conductivity because of the mesh structure.

Furthermore, a transparent electrode with a smooth surface is required for an electrode for an organic electroluminescence element. In particular, in the case of an electrode for an organic electroluminescence element, an ultra-thin film of an organic compound is formed on the electrode, so that an excellent surface smoothness is required for the transparent electrode. In the organic electroluminescence element, when the surface height difference (surface unevenness) of the anode is large, the electric field concentrates on the protrusion (protrusion) and the EL element is destroyed, or the protrusion is short-circuited with the cathode, Non-light emitting points (points that do not emit light on the surface of the electroluminescence element) may occur. Further, in the patterned electrode, the film thickness of the organic compound at the electrode pattern edge portion becomes thin, and current leakage is likely to occur therefrom. When these phenomena occur, the durability of the organic electroluminescence element is remarkably lowered. Therefore, excellent smoothness is required for the transparent electrode as the anode.

Patent Document 4 describes an inorganic electroluminescent element using a transparent conductive sheet in which ITO is coated on a metal fine wire mesh pattern. However, organic matter that requires higher smoothness than an inorganic electroluminescent element is described. No mention is made of electroluminescence elements.

Patent Document 5 describes a method for producing a flexible resin film with an electrode layer comprising a step of peeling both an ultraviolet curable resin layer and an electrode layer from a temporary support plate. The arithmetic average roughness Ra serving as an index is not mentioned at all, and the formation of the electrode layer is limited to the vacuum deposition method or the sputtering method, which has the disadvantage that the manufacturing cost and equipment are expensive.

JP 2003-46293 A JP 2004-221564 A US Patent Application Publication No. 2007 / 0074316A1 JP 2006-352073 A JP 2006-236626 A

The object of the present invention has been made in view of the above circumstances, and simply provides a transparent electrode having excellent conductivity and transparency and high smoothness, a method for producing the same, and an organic electroluminescence device using the transparent electrode. There is to do.

The above object of the present invention can be achieved by the following configuration.

1. A transparent electrode having a patterned conductive portion and a non-pattern portion on a transparent support, wherein the conductive portion contains a metal nanowire and a conductive polymer, or a metal nanowire and a metal oxide, and the non-pattern The portion contains a resin, the arithmetic average roughness Ra of the surface of the conductive portion is 5 nm or less, the maximum height Rz is 50 nm or less, and the maximum height difference between the conductive portion and the non-patterned portion is 50 nm or less. A transparent electrode characterized by that.

2. 2. An organic electroluminescence device comprising the transparent electrode as described in 1 above.

3. A method for producing a transparent electrode having a patterned conductive portion and a non-patterned portion on a transparent support, wherein the conductive portion contains a metal nanowire and a conductive polymer, or a metal nanowire and a metal oxide, The non-patterned portion contains a resin, and the first support is formed after the conductive portion previously formed on the first support is bonded to the resin-containing layer formed on the second support in advance. A method for producing a transparent electrode, comprising peeling off the body.

4. 4. The method for producing a transparent electrode as described in 3 above, wherein the conductive part is formed by a liquid phase film forming method.

According to the present invention, a transparent electrode having excellent conductivity and transparency and high smoothness, a method for producing the same, and an organic electroluminescence device using the transparent electrode can be easily provided.

It is sectional drawing before the transcription | transfer which shows the electroconductive part formed on the 1st support body. The conductive part formed on the first support is bonded to the resin-containing layer formed on the second support, embedded, transferred, and then the transparent electrode after the first support is peeled off. It is sectional drawing. It is the figure which looked at the transparent electrode which has an electroconductive part and a non-pattern part from the transparent electrode surface side.

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

FIG. 1 shows a conductive part 2 made of a patterned metal nanowire and a conductive polymer and a conductive part 3 made of a patterned metal nanowire and a metal oxide on a first support 1. It is sectional drawing before transcribe | transferring to the layer (non-display) containing the resin formed on the support body.

FIG. 2 shows a conductive part 2 made of a patterned metal nanowire and a conductive polymer and a conductive part 3 made of a patterned metal nanowire and a metal oxide on the first support 1. It is sectional drawing of the transparent electrode 20 produced by peeling the 1st support body 1 after adhere | attaching on the layer containing the resin formed on this support body 10, embedding, and transferring.

FIG. 3 shows a transparent part having a conductive part 2 made of a patterned metal nanowire and a conductive polymer, a conductive part 3 made of a patterned metal nanowire and a metal oxide, and a non-conductive non-pattern part 4. It is the figure which looked at the electrode 20 from the transparent electrode surface side.

Hereinafter, the present invention and its components will be described in detail.

[Support]
In the present invention, a plastic film, a plastic plate, glass or the like can be used as the transparent support.

Examples of raw materials for plastic films and plastic plates include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene and EVA, polyvinyl chloride, and polychlorinated chloride. Use vinyl resins such as vinylidene, polyether ether ketone (PEEK), polysulfone (PSF), polyether sulfone (PES), polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), etc. Can do.

In the method for producing a transparent electrode of the present invention, a material having excellent surface smoothness is used for the first support in order to smooth the peeled surface of the peeled patterned conductive part and the adhesive layer. . The smoothness (unevenness) of the surface of the first support is preferably such that the arithmetic average roughness Ra is 5 nm or less, the maximum height Rz is 50 nm or less, Ra is 2 nm or less, and Rz is 30 nm or less. More preferably, Ra is 1 nm or less, and Rz is 20 nm or less.

The surface of the first support may be smoothed by applying an undercoat layer such as a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or a radiation curable resin, or by machining such as polishing. It can be smooth. Further, a release layer may be formed to facilitate peeling, and as a release layer forming material, a polymer or wax that forms a known release layer can be appropriately selected and used. For example, paraffin wax, acrylic , Urethane, silicon, melamine, urea, urea-melamine, cellulose, benzoguanamine, and other resins and surfactants were dissolved in an organic solvent or water mainly composed of these or a mixture thereof. The paint is applied onto the support by ordinary printing methods such as gravure printing, screen printing, offset printing, etc., and dried (thermosetting resin, ultraviolet curable resin, electron beam curable resin, radiation curable resin, etc.) Examples of the curable coating film include those formed by curing. The thickness of the release layer is not particularly limited, and is suitably selected from the range of about 0.1 to 3 μm.

Here, Ra and Rz representing the smoothness (unevenness) of the surface of the first support means Ra = arithmetic mean roughness and Rz = maximum height (height difference between the top and bottom of the surface). And it is a value according to the surface roughness prescribed | regulated to JISB601 (2001). In the present invention, Ra and Rz can be measured by using a commercially available atomic force microscope (AFM), for example, by the following method.

Using an SPI 3800N probe station and SPA400 multifunctional unit manufactured by Seiko Instruments Inc. as the AFM, set the sample cut to a size of about 1 cm square on a horizontal sample stage on the piezo scanner, and place the cantilever on the sample surface. When approaching and reaching the region where the atomic force works, scanning is performed in the XY direction, and the unevenness of the sample at that time is captured by the displacement of the piezo in the Z direction. A piezo scanner that can scan XY 150 μm and Z 5 μm is used. The cantilever is a silicon cantilever SI-DF20 manufactured by Seiko Instruments Inc., which has a resonance frequency of 120 to 150 kHz and a spring constant of 12 to 20 N / m, and is measured in a DFM mode (Dynamic Force Mode). A measurement area of 80 × 80 μm is measured at a scanning frequency of 0.1 Hz.

In the method for producing a transparent electrode of the present invention, the second support is preferably provided with a gas barrier layer for the purpose of blocking oxygen and moisture in the atmosphere. As a material for forming the gas barrier layer, metal oxides such as silicon oxide, silicon nitride, silicon oxynitride, aluminum nitride, and aluminum oxide, and metal nitrides can be used. These materials have an oxygen barrier function in addition to a water vapor barrier function. In particular, silicon nitride and silicon oxynitride having favorable barrier properties, solvent resistance, and transparency are preferable. In addition, the barrier layer may have a multilayer structure as necessary. As a method for forming the gas barrier layer, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used depending on the material.

The thickness of each inorganic layer constituting the gas barrier layer is not particularly limited, but typically it is preferably in the range of 5 nm to 500 nm per layer, more preferably 10 nm to 200 nm per layer.

The gas barrier layer is provided on at least one surface of the second support, and is preferably provided on the adhesive layer adhesion side, and more preferably on both surfaces.

[Metal nanowires]
In general, a metal nanowire refers to a linear structure having a diameter from the atomic scale to the nm size, which contains a metal element as a main component.

The metal nanowire used in the present invention preferably has an average length of 3 μm or more, more preferably 3 to 500 μm, particularly 3 to 300 μm in order to form a long conductive path with one metal nanowire. It is preferable. In addition, the relative standard deviation of the length is preferably 40% or less. Moreover, it is preferable that an average diameter is small from a transparency viewpoint, On the other hand, the larger one is preferable from an electroconductive viewpoint. In the present invention, the average diameter of the metal nanowire is preferably 10 to 300 nm, and more preferably 30 to 200 nm. In addition, the relative standard deviation of the diameter is preferably 20% or less.

There is no restriction | limiting in particular as a metal composition of the metal nanowire which concerns on this invention, Although it can comprise from the 1 type or several metal of a noble metal element and a base metal element, noble metals (for example, gold, platinum, silver, palladium, rhodium, (Iridium, ruthenium, osmium, etc.) and at least one metal belonging to the group consisting of iron, cobalt, copper, and tin is preferable, and at least silver is more preferable from the viewpoint of conductivity. In order to achieve both conductivity and stability (sulfurization and oxidation resistance of metal nanowires and migration resistance), it is also preferable to include silver and at least one metal belonging to a noble metal other than silver. When the metal nanowire according to the present invention includes two or more kinds of metal elements, for example, the metal composition may be different between the inside and the surface of the metal nanowire, or the entire metal nanowire has the same metal composition. May be.

In the present invention, there are no particular limitations on the means for producing the metal nanowire, and for example, known means such as a liquid phase method and a gas phase method can be used. Moreover, there is no restriction | limiting in particular in a specific manufacturing method, A well-known manufacturing method can be used. For example, as a method for producing Ag nanowires, Adv. Mater. , 2002, 14, 833-837; Chem. Mater. 2002, 14, 4736-4745, etc., as a method for producing Co nanowires, such as JP 2006-233252, etc. as a method for producing Au nanowires, and JP 2002-266007, etc., as a method for producing Cu nanowires. Reference can be made to Japanese Unexamined Patent Publication No. 2004-149871. In particular, Adv. Mater. And Chem. Mater. The method for producing Ag nanowires reported in (1) can be easily produced in an aqueous system, and since the conductivity of silver is the highest among metals, it is preferable as the method for producing metal nanowires according to the present invention. Can be applied.

[Conductive polymer]
The conductive polymer used in the present invention is not particularly limited, and polypyrrole, polyindole, polycarbazole, polythiophene (including basic polythiophene, the same shall apply hereinafter), polyaniline, polyacetylene, polyfuran, and polyparaphenylene. Chain conductive polymers such as vinylene, polyazulene, polyparaphenylene, polyparaphenylene sulfide, polyisothianaphthene, and polythiazyl, and polyacene conductive polymers can also be used. Of these, polyethylene dioxythiophene (PEDOT) and polyaniline are preferable from the viewpoints of conductivity and transparency.

Moreover, in this invention, in order to raise the electroconductivity of the said conductive polymer more, it is preferable to perform a doping process. Examples of the dopant for the conductive polymer include a sulfonic acid having a hydrocarbon group having 6 to 30 carbon atoms (hereinafter also referred to as “long-chain sulfonic acid”) or a polymer thereof (for example, polystyrene sulfonic acid), halogen , Lewis acid, proton acid, transition metal halide, transition metal compound, alkali metal, alkaline earth metal, MClO ₄ (M = Li ⁺ , Na ⁺ ), R ₄ N ⁺ (R═CH ₃ , C ₄ H ₉ , C ₆ H ₅ ), or R ₄ P ⁺ (R═CH ₃ , C ₄ H ₉ , C ₆ H ₅ ). Of these, the long-chain sulfonic acid is preferable.

Examples of the long chain sulfonic acid include dinonyl naphthalene disulfonic acid, dinonyl naphthalene sulfonic acid, and dodecylbenzene sulfonic acid. Examples of the halogen include Cl ₂ , Br ₂ , I ₂ , ICl ₃ , IBr, IF _{5 and the} like. Examples of the Lewis acid include PF ₅ , AsF ₅ , SbF ₅ , BF ₃ , BCl ₃ , BBr ₃ , SO ₃ , GaCl _{3 and the} like. Examples of the protonic acid include HF, HCl, HNO ₃ , H ₂ SO ₄ , HBF ₄ , HClO ₄ , FSO ₃ H, ClSO ₃ H, CF ₃ SO ₃ H, and the like. The transition metal _{_{_{_{halide, NbF 5, TaF 5, MoF}}}} 5, WF 5, RuF 5, BiF 5, TiCl 4, ZrCl 4, MoCl 5, MoCl 3, WCl 5, FeCl 3, TeCl 4, SnCl 4, SeCl ₄ , FeBr ₃ , SnI _{5 and the} like. The transition metal _{_{_{_{compound, AgClO 4, AgBF 4, La}}}} (NO 3) 3, Sm (NO 3) 3 and the like. Examples of the alkali metal include Li, Na, K, Rb, and Cs. Examples of the alkaline earth metal include Be, Mg, Ca, Sc, and Ba.

The dopant for the conductive polymer may be introduced into fullerenes such as hydrogenated fullerene, hydroxylated fullerene, and sulfonated fullerene. It is preferable that 0.001 mass part or more of the said dopant is contained with respect to 100 mass parts of conductive polymers. Furthermore, it is more preferable that 0.5 mass part or more is contained. The transparent conductive composition of the present embodiment includes a long-chain sulfonic acid, a polymer of long-chain sulfonic acid (for example, polystyrene sulfonic acid), halogen, Lewis acid, proton acid, transition metal halide, transition metal compound, Both at least one dopant selected from the group consisting of alkali metals, alkaline earth metals, MClO ₄ , R ₄ N ⁺ , and R ₄ P ⁺ and fullerenes may be included.

The conductive polymer used in the present invention is 2nd. A water-soluble organic compound may be contained as a dopant. There is no restriction | limiting in particular in the water-soluble organic compound which can be used by this invention, It can select suitably from well-known things, For example, an oxygen containing compound is mentioned suitably.
The oxygen-containing compound is not particularly limited as long as it contains oxygen, and examples thereof include a hydroxyl group-containing compound, a carbonyl group-containing compound, an ether group-containing compound, and a sulfoxide group-containing compound. Examples of the hydroxyl group-containing compound include ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, glycerin and the like. Among these, ethylene glycol and diethylene glycol are preferable. Examples of the carbonyl group-containing compound include isophorone, propylene carbonate, cyclohexanone, γ-butyrolactone, and the like. Examples of the ether group-containing compound include diethylene glycol monoethyl ether. Examples of the sulfoxide group-containing compound include dimethyl sulfoxide. These may be used alone or in combination of two or more, but it is particularly preferable to use at least one selected from dimethyl sulfoxide, ethylene glycol, and diethylene glycol.

In the conductive polymer used in the present invention, the 2nd. The content of the dopant is preferably 0.001 part by mass or more, more preferably 0.01 to 50 parts by mass, and particularly preferably 0.01 to 10 parts by mass.

[Metal oxide]
The metal oxide used in the present invention is not particularly limited, but fine particles such as indium oxide, zinc oxide, cadmium oxide, gallium oxide, antimony oxide, aluminum oxide, or other metal elements are added to these oxides. Fine particles such as tin-added indium oxide (ITO), antimony-added tin oxide (ATO), zinc-added indium oxide (IZO), aluminum-added zinc oxide (AZO), and gallium-added zinc oxide (GZO) are preferably used.

Among these metal oxides, those that constitute a transparent conductive film include tin-added indium oxide (ITO), antimony-added tin oxide (ATO), zinc-added indium oxide (IZO), and aluminum-added zinc oxide (AZO). Further, gallium-doped zinc oxide (GZO), indium oxide (In ₂ O ₃ ), zinc oxide (ZnO), and the like are preferable.

The average particle diameter of the metal oxide is preferably 1 to 100 nm, particularly preferably 3 to 50 nm. The average particle size of the metal oxide was the BET particle size calculated by the following formula.

BET particle size (nm) = 6 / (ρ × specific surface area) × 10 ⁹
However, ρ is the true specific gravity of the transparent conductive fine particles. For example, when the metal oxide is ITO (tin-containing indium oxide), ρ = 7.13 × 10 ⁹ (g / m ³ ). The specific surface area can be determined by the BET method (one point method).

[Conductive part]
The patterned conductive part in the present invention is characterized by containing metal nanowires and a conductive polymer, or metal nanowires and a metal oxide. Either one or both of the conductive polymer and the metal oxide contained in the conductive part in the present invention may be used. The metal nanowires of the conductive part are preferably in contact with each other, and more preferably in mesh form. Conductive portions in which metal nanowires are brought into contact with each other or meshed can be easily obtained by using the following liquid phase film forming method.

The method for forming a conductive part in the present invention is not particularly limited as long as it is a liquid phase film forming method in which a dispersion containing metal nanowires and a dispersion containing a conductive polymer or metal oxide are applied and dried to form a film. Roll coating method, bar coating method, dip coating method, spin coating method, casting method, die coating method, blade coating method, bar coating method, gravure coating method, curtain coating method, spray coating method, doctor coating method, etc. It is preferable to use a printing method such as a printing method, a letterpress (letterpress) printing method, a stencil (screen) printing method, a lithographic (offset) printing method, an intaglio (gravure) printing method, a spray printing method, and an ink jet printing method.

In the present invention, the dispersion containing the metal nanowires is applied to the first support and dried, and then the dispersion containing the conductive polymer or the metal oxide is applied and dried. Molecules or metal nanowires and metal oxides are preferably present on the electrode surface and in the vicinity of the electrode surface in the conductive part. As a result, the number of contact points between the metal nanowires increases and the conductivity is improved, and further, the conductive polymer or the metal oxide enters the gaps between the metal nanowires formed in a mesh shape. The conductivity of the part can be made uniform.

The dispersion containing metal nanowires and the dispersion containing a conductive polymer or metal oxide used in the present invention may contain a transparent binder material or additive. The transparent binder material can be selected from a wide range of natural polymer resins or synthetic polymer resins. For example, transparent thermoplastic resins (eg, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, nitrocellulose, chlorinated polyethylene, chlorinated polypropylene, vinylidene fluoride), heat / light / electron beam A transparent curable resin that is cured by radiation (for example, melamine acrylate, urethane acrylate, epoxy resin, polyimide resin, silicon resin such as acrylic-modified silicate) can be used. Examples of the additive include plasticizers, stabilizers such as antioxidants and sulfurization inhibitors, surfactants, dissolution accelerators, polymerization inhibitors, and colorants such as dyes and pigments. Furthermore, from the viewpoint of improving workability such as coating properties, solvents (for example, organic solvents such as water, alcohols, glycols, cellosolves, ketones, esters, ethers, amides, hydrocarbons, etc.) are used. May be included.

[Patterning]
As a method for patterning a conductive portion in the present invention, a photolithography method in which a conductive portion is formed on a support and then patterned by chemical etching using a photoresist can be used. As another method of patterning the conductive portion, a portion to be a non-pattern portion may be peeled off using a lift-off resist to form a conductive portion pattern, or a desired pattern may be formed on the support using the printing method. The conductive part pattern may be formed, and after the conductive part is formed on the support, the part that becomes the conductive part pattern part is masked and the part that becomes the non-pattern part is wiped off physically. Also good.

[Non-pattern part]
The non-pattern part in this invention contains resin. The resin used is not particularly limited as long as it is transparent in the visible region (that is, has sufficient transmittance), but is preferably non-conductive having a surface specific resistance of 10 ¹⁰ Ω / □ or more. The surface specific resistance can be measured based on, for example, JIS K6911, ASTM D257, etc., and can be easily measured using a commercially available surface resistivity meter. The resin may be a curable resin or a thermoplastic resin. Examples of the curable resins include thermosetting resins, ultraviolet curable resins, and electron beam curable resins. Among these curable resins, the equipment for resin curing is simple and excellent in workability. Therefore, an ultraviolet curable resin is preferable. The non-pattern part is preferably an acrylic polymer or an epoxy polymer from the viewpoint of transparency. The non-patterned part of the present invention may be provided on the patterned conductive part formed on the first support, or provided on the second support and the patterned conductive part is non-patterned. After being bonded and buried on the part side, a curing process may be performed.

It is preferable that the non-pattern part does not contain the metal nanowire, the conductive polymer, and the metal oxide contained in the conductive part and is made of only a resin.

The bonding method is not particularly limited and can be performed by a sheet press, a roll press, or the like, but is preferably performed using a roll press machine. The roll press is a method in which a film to be bonded is sandwiched between the rolls, and the rolls are rotated. The roll press is uniformly pressed and has better productivity than the sheet press.

The transparent electrode of the present invention can be obtained by peeling the first support after performing the adhesion and curing treatment by the above method.

[Transparent electrode]
The arithmetic average roughness Ra of the conductive portion in the transparent electrode of the present invention is 5 nm or less, the maximum height Rz is 50 nm or less, Ra is 2 nm or less, and Rz is preferably 30 nm or less, more preferably Ra is 1 nm or less and Rz is 20 nm or less. The arithmetic average roughness Ra and the maximum height Rz of the conductive portion can be measured in the same manner as the arithmetic average roughness Ra and the maximum height Rz of the surface of the support described above.

The total light transmittance of the conductive part in the transparent electrode of the present invention is desirably 60% or more, preferably 70% or more, and particularly preferably 80% or more. The total light transmittance can be measured according to a known method using a spectrophotometer or the like.

The electrical resistance value of the pattern portion in the transparent electrode of the present invention is preferably 10 ³ Ω / □ or less, more preferably 10 ² Ω / □ or less, and more preferably 10 Ω / □ or less as the surface specific resistance. It is particularly preferred. The surface specific resistance can be measured based on, for example, JIS K6911, ASTM D257, etc., and can be easily measured using a commercially available surface resistivity meter. The surface specific resistance only needs to satisfy the surface specific resistance in the state of the metal nanowire alone, and the metal nanowire functions as a bus electrode. Therefore, even if the surface specific resistance of the conductive polymer or metal oxide is high, the conductive portion Can be made uniform. The surface specific resistance of the conductive polymer or metal oxide is preferably 10 ⁹ Ω / □ or less.

An anchor coat or a hard coat can be applied to the transparent electrode of the present invention. Moreover, you may install the electroconductive part containing a conductive polymer or a metal oxide as needed.

The transparent electrode of the present invention can be used for transparent electrodes such as LCDs, electroluminescent elements, plasma displays, electrochromic displays, solar cells, touch panels, electronic papers, electromagnetic shielding materials, etc., but has excellent conductivity and transparency. In addition, since it has high smoothness, it is preferably used for an organic electroluminescence element.

[Organic electroluminescence device]
The organic electroluminescent element in the present invention has the transparent electrode of the present invention. The organic electroluminescence device in the present invention uses the transparent electrode of the present invention as an anode, and the organic light emitting layer and the cathode may be any material or configuration generally used in organic electroluminescence devices. it can.

The element configuration of the organic electroluminescence element is anode / organic light emitting layer / cathode, anode / hole transport layer / organic light emitting layer / electron transport layer / cathode, anode / hole injection layer / hole transport layer / organic light emitting layer / electron transport. Examples of various configurations such as layer / cathode, anode / hole injection layer / organic light emitting layer / electron transport layer / electron injection layer / cathode, anode / hole injection layer / organic light emitting layer / electron injection layer / cathode, etc. Can do.

In addition, as the light emitting material or doping material that can be used in the organic light emitting layer in the present invention, anthracene, naphthalene, pyrene, tetracene, coronene, perylene, phthaloperylene, naphthaloperylene, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, bisbenzo Xazoline, bisstyryl, cyclopentadiene, quinoline metal complex, tris (8-hydroxyquinolinato) aluminum complex, tris (4-methyl-8-quinolinato) aluminum complex, tris (5-phenyl-8-quinolinato) aluminum complex, Aminoquinoline metal complex, benzoquinoline metal complex, tri- (p-terphenyl-4-yl) amine, 1-aryl-2,5-di (2-thienyl) pyrrole derivative, pyran, quinaclide , Rubrene, distyrylbenzene derivatives, di still arylene derivatives, and various fluorescent dyes and rare earth metal complex, there are phosphorescent materials, but is not limited thereto. It is also preferable to include 90 to 99.5 parts by mass of a light emitting material selected from these compounds and 0.5 to 10 parts by mass of a doping material. The organic light emitting layer is produced by a known method using the above materials and the like, and examples thereof include vapor deposition, coating, and transfer. The thickness of the organic light emitting layer is preferably 0.5 to 500 nm, particularly preferably 0.5 to 200 nm.

The organic electroluminescence element in the present invention can be used for a self-luminous display, a backlight for liquid crystal, illumination and the like. Since the organic electroluminescent element of the present invention can emit light uniformly and without unevenness, it is preferably used for illumination.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Example 1
<< Preparation of transparent electrode >>
[Preparation of transparent electrode TCF-1; comparative example]
An ITO film was deposited on a polyethylene terephthalate film support having a thickness of 100 μm with an average film thickness of 150 nm, then cut into 50 mm × 50 mm square, and a striped transparent pattern electrode TCF-1 having a conductive part pattern width of 10 mm was formed by photolithography. Produced.

[Preparation of transparent electrode TCF-2; comparative example]
With reference to the method described in Non-Patent Document 4 (Adv. Mater., 2002, 14, 833-837), silver nanowires were produced by the following method.

(Nucleation process)
While stirring 1000 ml of the EG solution maintained at 170 ° C. in the reaction vessel, 100 ml of an ethylene glycol solution of silver nitrate (silver nitrate concentration: 1.5 × 10 ⁻⁴ mol / L) was added at a constant flow rate for 10 seconds. Thereafter, aging was carried out at 170 ° C. for 10 minutes to form silver core particles. The reaction solution after completion of ripening exhibited a yellow color derived from surface plasmon absorption of silver nanoparticles, and it was confirmed that silver ions were reduced and silver nanoparticles were formed.

(Particle growth process)
The reaction solution containing the core particles after the ripening was kept at 170 ° C. while stirring, 1000 ml of an ethylene glycol solution of silver nitrate (silver nitrate concentration: 1.0 × 10 ⁻¹ mol / L), and ethylene glycol of polyvinylpyrrolidone. 1000 ml of a solution (vinyl pyrrolidone concentration conversion: 5.0 × 10 ⁻¹ mol / L) was added at a constant flow rate for 100 minutes using a double jet method. When the reaction solution was sampled every 20 minutes in the particle growth process and confirmed with an electron microscope, the silver nanoparticles formed in the nucleation process grew mainly in the long axis direction of the nanowires over time. No new core particles were observed in the grain growth process.

(Washing process)
After completion of the particle growth step, the reaction solution was cooled to room temperature, filtered using a filter, and the silver nanowires separated by filtration were redispersed in ethanol. Filtration of silver nanowires with a filter and redispersion in ethanol were repeated 5 times, and finally an ethanol dispersion of silver nanowires was prepared to produce silver nanowires.

A small amount of the obtained dispersion was collected and confirmed with an electron microscope, and it was confirmed that silver nanowires having an average diameter of 85 nm and an average length of 7.4 μm were formed.

Spin the prepared silver nanowire dispersion on a 100 μm thick polyethylene terephthalate film support that has been smoothed so that the weight per unit area of the silver nanowire is 0.05 g / m ^2. It was applied and dried using a coater. Subsequently, the silver nanowire coating layer was calendered and then cut into 50 mm × 50 mm square, and a striped transparent pattern electrode TCF-2 having an electrode pattern width of 10 mm was produced by photolithography.

[Preparation of transparent electrode TCF-3; comparative example]
In the transparent electrode TCF-2, the silver nanowire coating layer was calendered and then Baytron PH510 (manufactured by HC Starck) which was a dispersion of PEDOT: PSS (polystyrene sulfonic acid) = 1: 2.5 A transparent electrode TCF-3 was prepared in the same manner as TCF-2 except that a solution obtained by adding 5% of dimethyl sulfoxide to the solution was applied so that the dry film thickness was 100 nm.

[Preparation of transparent electrode TCF-4; comparative example]
(Preparation of adhesive film)
An easy-adhesion process is applied to one side of a 100 μm-thick polyethylene terephthalate film support, and an ultraviolet curable resin (UVPOT Medium 0, manufactured by Teikoku Ink Co., Ltd.) is applied as a resin layer on the easy-adhesive surface to a thickness of 3 μm. Thus, an adhesive film was produced.

The resin layer of the produced adhesive film was pressure-bonded so that the electrode pattern side of the transparent electrode TCF-2 faced. Next, ultraviolet rays were irradiated from the adhesive film side to cure the ultraviolet curable resin, and the adhesive film and the transparent electrode TCF-2 were joined.

The joined adhesive film and the transparent electrode TCF-2 were peeled off from the polyethylene terephthalate film support on the transparent electrode TCF-2 side to produce a transparent electrode TCF-4.

[Preparation of transparent electrode TCF-5; the present invention]
A transparent electrode TCF-5 was produced in the same manner as TCF-4 except that the transparent electrode to be pressure-bonded to the resin layer of the adhesive film was changed to TCF-3.

[Production of Transparent Electrode TCF-6; Present Invention]
In the transparent electrode TCF-5, the silver nanowire coating layer was calendered, and instead of the Baytron PH510 dimethyl sulfoxide 5% additive solution, an ITO dispersion (trade name; EI) manufactured by Gemco Co., Ltd. was used for the dry film thickness. A transparent electrode TCF-6 was produced in the same manner as TCF-4 except that the coating was applied to a thickness of 100 nm.

[Preparation of Transparent Electrode TCF-7; Present Invention]
In the production of the silver nanowire of the transparent electrode TCF-2, the same operation was performed except that the redispersion in ethanol was replaced with water in the water washing step. Furthermore, carboxymethylcellulose was added, and it adjusted so that a viscosity might be set to 30 cP (30 mPa * s), and produced the silver nanowire dispersion liquid. Similarly, the viscosity of the Baytron PH510 dimethyl sulfoxide 5% additive solution used in the transparent electrode TCF-3 was adjusted to 30 cP (30 mPa · s).

Next, the silver nanowire dispersion liquid whose viscosity was adjusted was subjected to gravure printing (K printing) using a plate in which a striped pattern with a width of 10 mm was formed on a 100 μm-thick smooth polyethylene terephthalate film support subjected to corona discharge treatment. Proofer: Matsuo Sangyo Co., Ltd.). The number of printings was adjusted so that the amount of silver nanowires was 0.05 g / m ² . Further, the silver nanowire layer was calendered.

Then, gravure printing was performed in the same manner using a Baytron PH510 dimethyl sulfoxide 5% addition solution so as to overlap the previously formed silver nanowire pattern. The number of printings was adjusted so that the dry film thickness was 100 nm.

Using this, the same operation as that of the transparent electrode TCF-4 was performed to produce a transparent electrode TCF-7.

[Preparation of Transparent Electrode TCF-8; Present Invention]
In the silver nanowire dispersion liquid and Baytron PH510 dimethyl sulfoxide 5% addition liquid used in the transparent electrode TCF-7, carboxymethylcellulose was replaced with glycerin, and the viscosity was adjusted to 15 cP (15 mPa · s).

Next, the silver nanowire dispersion liquid whose viscosity was adjusted was mounted on an inkjet printer MJ-800C (manufactured by Seiko Epson Corporation), and was subjected to corona discharge treatment. A pattern was formed. The printing density and the number of printings were adjusted so that the basis weight of the silver nanowires was 0.05 g / m ² . Further, the silver nanowire layer was calendered. Next, by using Baytron PH510 dimethyl sulfoxide 5% addition liquid, ink jet printing was performed on the previously formed silver nanowire pattern so that the dry film thickness was 100 nm.

Using this, the same operation as that of the transparent electrode TCF-4 was performed to produce a transparent electrode TCF-8.

<< Measurement and evaluation of transparent electrodes >>
The transmittance, surface resistivity measurement, and surface shape of the transparent electrodes TCF-1 to 8 were evaluated by the following methods.

(Transmittance)
The transmittance was determined by measuring the total light transmittance of the conductive pattern portion using an AUTOMATIC ZEMETER (MODEL TC-HIIIDP) manufactured by Tokyo Denshoku.

(Surface resistivity)
For the surface specific resistance, the surface specific resistance of the conductive pattern portion was measured by a four-terminal method using a resistivity meter Loresta GP manufactured by Dia Instruments.

(Surface shape)
The surface shape is determined by measuring the electrode surface with an atomic force microscope (AFM), the arithmetic average roughness Ra and the maximum height Rz of the conductive part pattern part surface, the maximum height difference between the conductive part pattern part and the non-pattern part of the transparent electrode Asked.

The arithmetic average roughness Ra and the maximum height Rz of the conductive part pattern part surface are values according to the surface roughness specified in JIS B601 (2001). In the present invention, Ra and Rz are measured using commercially available atoms. Using an atomic force microscope (AFM), the following method was used.

Using an SPI 3800N probe station and SPA400 multifunctional unit manufactured by Seiko Instruments Inc. as the AFM, set the sample cut to a size of about 1 cm square on a horizontal sample stage on the piezo scanner, and place the cantilever on the sample surface. When approaching and reaching the region where the atomic force works, scanning was performed in the XY direction, and the unevenness of the sample at that time was captured by the displacement of the piezo in the Z direction. A piezo scanner that can scan XY 150 μm and Z 5 μm was used. The cantilever was a silicon cantilever SI-DF20 manufactured by Seiko Instruments Inc., which had a resonance frequency of 132 kHz and a spring constant of 15 N / m, and was measured in the DFM mode (Dynamic Force Mode). A measurement area of 80 × 80 μm was measured at a scanning frequency of 0.1 Hz.

In addition, in the film support used for applying the conductive portion with the transparent electrodes TCF-4 to 6, the arithmetic average roughness Ra and the maximum height Rz on the coated surface side of the support before applying the conductive portion are each 0.6 nm. 18 nm.

Table 1 shows the results of measurement and evaluation.

Table 1 shows that the transparent electrode of the present invention is excellent in conductivity (surface specific resistance) and transparency (transmittance) and high in smoothness (surface shape).

Example 2
<< Production of organic electroluminescence element >>
Using the transparent electrodes TCF-1 to 8 produced in Example 1 as the first electrode (anode), organic EL elements OLED-1 to OLED-1 to 8 were produced respectively by the following procedure.

<Formation of hole transport layer>
On the first electrode, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), which is a hole transport material, is added to 1% by mass in 1,2-dichloroethane. The dissolved coating solution for forming a hole transport layer was applied by a spin coater and then dried at 80 ° C. for 60 minutes to form a hole transport layer having a thickness of 40 nm.

<Formation of light emitting layer>
On each film in which the hole transport layer is formed, the host material polyvinylcarbazole (PVK) is 1% red dopant material Btp ₂ Ir (acac), ₂ % green dopant material Ir (ppy) ₃ , A coating solution for forming a light emitting layer in which blue dopant material FIr (pic) is mixed to 3% and dissolved in 1,2-dichloroethane so that the total solid concentration of PVK and the three dopants is 1%. Was applied with a spin coater and then dried at 100 ° C. for 10 minutes to form a light emitting layer having a thickness of 60 nm.

<Formation of electron transport layer>
On the formed light emitting layer, LiF was deposited as an electron transport layer forming material under a vacuum of 5 × 10 ⁻⁴ Pa to form an electron transport layer having a thickness of 0.5 nm.

<Formation of second electrode>
On the formed electron transport layer, Al is formed as a second electrode (cathode) forming material under a vacuum of 5 × 10 ⁻⁴ Pa so as to be perpendicular to the conductive portion of the first electrode in a stripe shape having a width of 10 mm. Mask evaporation was performed to form a second electrode having a thickness of 100 nm.

<Formation of sealing film>
On the formed electron transport layer, a polyethylene terephthalate as a substrate, using a flexible sealing member which is deposited to a thickness 300nm of Al ₂ O _3. Except for the edges so that external lead terminals of the first electrode and the second electrode can be formed, after applying an adhesive around the second electrode and pasting a flexible sealing member, the adhesive is cured by heat treatment. I let you.

<< Evaluation of organic electroluminescence element >>
The following methods were used to evaluate the emission luminance unevenness and the rectification ratio of the organic electroluminescence elements OLED-1 to OLED-8.

(Light emission brightness unevenness)
Using a source measure unit type 2400 manufactured by KEITHLEY, a direct current voltage was applied to the produced organic electroluminescence elements OLED-1 to OLED-6 to emit light. About each organic electroluminescent element made to light-emit at 200 cd / m < ² >, the light emission nonuniformity of the whole light emission surface at the time of lighting was evaluated by the following reference | standard by visual observation.

◎: 90% or more emits uniformly ○: 80% or more emits uniformly △: 70% or more emits uniformly ×: Less than 70% emits XX: no Does not emit light (rectification ratio)
A current value when a voltage of +3 V / −3 V was applied to the produced organic electroluminescence elements OLED-1 to OLED-1 to 8 was measured, and a rectification ratio was obtained by the following formula.

Rectification ratio = current value when + 3V is applied / current value when -3V is applied Table 2 shows the evaluation results.

As is apparent from Table 2, when the transparent electrode of the present invention having excellent conductivity and transparency and high smoothness is used as the electrode of the organic electroluminescence element, the organic electroluminescence element has little emission luminance unevenness and current leakage. I understand that.

DESCRIPTION OF SYMBOLS 1 1st support body 2 Conductive part which consists of metal nanowire and conductive polymer 3 Conductive part which consists of metal nanowire and metal oxide 4 Non-pattern part 10 2nd support body 20 Transparent electrode

Claims

A transparent electrode having a patterned conductive portion and a non-pattern portion on a transparent support, wherein the conductive portion contains a metal nanowire and a conductive polymer, or a metal nanowire and a metal oxide, and the non-pattern The portion contains a resin, the arithmetic average roughness Ra of the surface of the conductive portion is 5 nm or less, the maximum height Rz is 50 nm or less, and the maximum height difference between the conductive portion and the non-patterned portion is 50 nm or less. A transparent electrode characterized by that.
An organic electroluminescence device comprising the transparent electrode according to claim 1.
A method for producing a transparent electrode having a patterned conductive portion and a non-patterned portion on a transparent support, wherein the conductive portion contains a metal nanowire and a conductive polymer, or a metal nanowire and a metal oxide, The non-patterned portion contains a resin, and the first support is formed after the conductive portion previously formed on the first support is bonded to the resin-containing layer formed on the second support in advance. A method for producing a transparent electrode, comprising peeling off the body.
The method for producing a transparent electrode according to claim 3, wherein the conductive portion is formed by a liquid phase film forming method.