WO2010082428A1

WO2010082428A1 - Transparent electrode, method for producing same, and organic electroluminescent element

Info

Publication number: WO2010082428A1
Application number: PCT/JP2009/071121
Authority: WO
Inventors: 竹田　昭彦; 昌紀後藤; 中村　和明
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2009-01-19
Filing date: 2009-12-18
Publication date: 2010-07-22
Also published as: JP5533669B2; JPWO2010082428A1

Abstract

Disclosed is a transparent electrode which exhibits excellent surface smoothness, electrical conductivity and transparency, while having high productivity. The transparent electrode comprises, on a transparent supporting body, a conductive layer that is composed of a metal nanowire layer and a conductive polymer layer, and is characterized in that the metal nanowire layer contains at least one substance selected from among crosslinked products of water-soluble polymers, crosslinked products of polymer latexes and cured products of curable resins.

Description

Transparent electrode, method for producing the same, and organic electroluminescence device

The present invention relates to a transparent electrode, a method for producing the same, and an organic electroluminescent element, and more specifically, relates to a transparent electrode formed by coating without complicated processes, a method for producing the same, and an organic electroluminescent element.

In recent years, various types of display technologies such as liquid crystal, plasma, organic electroluminescence (hereinafter referred to as organic EL), field emission, and the like 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 doped with antimony (FTO, ATO), 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 conductive oxide typified by the above-mentioned ITO or the like forms a transparent conductive film on the substrate surface by a vacuum process such as a sputtering method or a liquid phase method such as a sol-gel method. In order to form a transparent conductive film by a vacuum process such as sputtering, expensive equipment is required.

In order to solve such problems, a method of forming a transparent conductive film by applying a conductive oxide or a composition containing a conductive polymer has been proposed (for example, Patent Document 1). 2).

However, it is difficult to obtain sufficient electrical conductivity by these methods, and it is difficult to achieve both light transmittance and electrical conductivity, particularly in applications such as organic EL elements and solar cells.

Other transparent electrodes include a transparent electrode in which a mesh structure is formed by a metal pattern typified by an electromagnetic wave shielding film of a plasma display (for example, Patent Document 3), and a transparent electrode composed of a fine mesh using metal nanowires. An electrode is disclosed (for example, Patent Document 4). 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, these transparent electrodes have a defect that the electrode surface is rough as compared with the above-mentioned electrodes such as ITO. In particular, in the case of an organic EL element, since an ultra-thin film of an organic compound is formed on the electrode, the transparent electrode is required to have excellent surface smoothness, and such an electrode with low surface smoothness causes luminance unevenness or the like. This causes a decrease in the function of the element.

In order to improve the surface smoothness of the transparent electrode, a method of forming a conductive layer using a metal nanowire on a highly smooth support and transferring it to another support has been proposed (Patent Document 4). It is difficult to adjust the balance between the adhesive used for transfer and the adhesion between the support and the conductive layer and the peelability, and complete transfer is difficult. Furthermore, there are many steps of applying and curing the adhesive layer, laminating and peeling the supports, peeling, and processes, and there is a problem of cost increase. Further, a method for directly forming the conductive layer pattern by a printing method is not described in detail.

JP 2008-95015 A Japanese Patent Laid-Open No. 2008-4501 JP 2004-221564 A US Patent Application Publication No. 2007 / 0074316A1

An object of the present invention is made in view of the above circumstances, and is to provide a transparent electrode excellent in surface smoothness, conductivity, and transparency, and having high productivity, and a method for producing the same.

Particularly, it is an object to provide a transparent electrode in which a conductive polymer layer is formed on a metal nanowire layer fixed with a cross-linked resin or a cured resin, and a method for producing the same.

Furthermore, an object of the present invention is to provide an organic electroluminescence device with less luminance unevenness by using the transparent electrode manufactured in this way.

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

1. In a transparent electrode having a conductive layer composed of a metal nanowire layer and a conductive polymer layer on a transparent support, a cross-linked product of a water-soluble polymer, a cross-linked product of a polymer latex, and a curable resin in the metal nanowire layer A transparent electrode comprising at least one selected from the cured products.

2. 2. The transparent electrode as described in 1 above, wherein the water-soluble polymer is polyvinyl alcohol or a cellulose derivative.

3. The water-soluble polymer cross-linked product or polymer latex cross-linked product is cross-linked with at least one cross-linking agent selected from aldehyde, melamine, epoxy, and isocyanate cross-linking agents. 2. The transparent electrode according to 1 above, wherein the transparent electrode is provided.

4. 4. The transparent electrode according to 1, 2, or 3, wherein the metal nanowire of the metal nanowire layer is a silver nanowire.

5. 5. The method for producing a transparent electrode according to any one of 1 to 4, wherein the transparent electrode forms a metal nanowire layer comprising metal nanowires and a binder on a transparent support, and then the metal nanowire layer is formed. A method for producing a transparent electrode, which is produced by crosslinking or curing a binder and then forming a conductive polymer layer.

6. 6. The method for producing a transparent electrode as described in 5 above, wherein the binder is contained in a dispersion for forming the metal nanowire layer.

7. 5. An organic electroluminescence device comprising the transparent electrode according to any one of 1 to 4 above.

According to the present invention, it is possible to easily and inexpensively provide a transparent electrode having surface smoothness, conductivity, and transparency. Furthermore, by using silver nanowires as metal nanowires, both conductivity and transparency are achieved. A transparent electrode can be provided.

Further, by using the transparent electrode of the present invention as the electrode of the organic electroluminescence element, it was possible to provide an organic electroluminescence element with little uneven emission luminance.

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 according to the present invention, the support is preferably excellent in surface smoothness. The smoothness of the surface is preferably an arithmetic average roughness Ra of 5 nm or less and a maximum height Rz of 50 nm or less, more preferably Ra of 2 nm or less and Rz of 30 nm or less, and still more preferably Ra of 1 nm or less. Rz is 20 nm or less. The surface of the 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 may be smoothed by mechanical processing such as polishing. You can also. In order to improve the coating and adhesion of the polymer layer, a surface treatment using corona or plasma, or an easy adhesion layer may be formed. Here, the smoothness of the surface can be determined according to a surface roughness standard (JIS B 0601-2001) from measurement using an atomic force microscope (AFM) or the like.

It is also preferable to provide 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, and more preferably 10 nm to 200 nm per layer.

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

<Conductive layer>
The conductive layer in the present invention is composed of a metal nanowire layer and a conductive polymer layer, and the conductive polymer layer may be in contact with the surface of the metal nanowire layer or may be impregnated inside.

The method for forming these conductive layers is not particularly limited as long as it is a liquid phase film forming method in which a dispersion containing metal nanowires and a conductive polymer is applied and dried to form a film. Application methods such as dip coating, spin coating, casting, die coating, blade coating, bar coating, gravure coating, curtain coating, spray coating, and doctor coating can be used. Alternatively, direct pattern formation may be performed by an inkjet printing method, gravure, screen printing method, or the like, and printing may be performed a plurality of times depending on the concentration of the dispersion and the target coating amount.

<Metal nanowire layer>
The metal nanowire layer according to the present invention is formed by applying and drying a dispersion containing a metal nanowire and a water-soluble polymer or polymer latex or a curable resin as a binder. Further, the water-soluble polymer or polymer latex that is a binder is crosslinked by a crosslinking agent described later, and the curable resin is cured and fixed by heat, light, electron beam, or radiation. Thereby, the applicability | paintability and smoothness of a conductive polymer layer improve dramatically. This is presumed that the coating of the conductive polymer layer slightly swells the underlying metal nanowire layer, but the aforementioned immobilization suppresses the swelling and improves the smoothness.

Further, as additives, stabilizers such as plasticizers, antioxidants and antisulfurizing agents, surfactants, dissolution accelerators, polymerization inhibitors, and colorants such as dyes and pigments can be used. Furthermore, from the viewpoint of improving workability such as coating properties, solvents (for example, water, organic solvents such as alcohols, glycols, cellosolves, ketones, esters, ethers, amides, hydrocarbons, etc.) are used. May be included.

Further, the dispersion containing metal nanowires may contain a conductive polymer.

<Water-soluble polymer>
Examples of the water-soluble polymer according to the present invention include natural polymers such as starch, gelatin, and agar. Semi-synthetic polymers such as carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), methyl cellulose (MC), and hydroxyethyl methyl cellulose (HEMC). , Cellulose derivatives such as hydroxypropylmethylcellulose (HPMC), synthetic polymer polyvinyl alcohol (PVA), polyacrylic acid polymer, polyacrylamide (PAM), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), etc. Can be used. In addition, in these polymers, a part of the functional group may be modified. In particular, a cellulose derivative and polyvinyl alcohol are preferable.

<Polymer latex>
Examples of the polymer latex according to the present invention include acrylic resins (acrylic silicon-modified resins, fluorine-modified acrylic resins, urethane-modified acrylic resins, epoxy-modified acrylic resins, etc.), polyester resins, polyurethane resins, vinyl acetate resins, and the like. Can be widely selected and used.

<Curable resin>
The curable resin according to the present invention may be an aqueous curable resin that is cured by heat, light, electron beam, or radiation. For example, silicone such as melamine acrylate, urethane acrylate, epoxy resin, polyimide resin, acrylic-modified silicate, etc. Resin or the like can be used.

<Conductive polymer layer>
The conductive polymer layer according to the present invention is formed by applying a metal nanowire layer and then crosslinking or curing the binder of the metal nanowire layer, and then applying and drying a dispersion containing the conductive polymer. .

The conductive polymer layer may be a single conductive polymer or a mixture of plural types of conductive polymers. In addition, a non-conductive polymer and an additive may be included as long as both conductivity and transparency can be achieved.

As the non-conductive polymer, a wide variety of natural polymer resins or synthetic polymer resins can be used. For example, a transparent thermoplastic resin (for example, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, nitrocellulose, chlorinated polyethylene, chlorinated polypropylene, vinylidene fluoride) or the above-mentioned water-soluble polymer Polymer latex and curable resin can be used.

Additives 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, water, organic solvents such as alcohols, glycols, cellosolves, ketones, esters, ethers, amides, hydrocarbons, etc.) are used. May be included.

In the present invention, by coating and laminating a conductive polymer layer on a metal nanowire layer, in addition to conductivity due to contact between the metal nanowires, the conductive polymer enters between the metal nanowires, and the metal nanowire and the metal nanowire gap The conductivity of the part can be made uniform. Furthermore, surface smoothness can be improved by forming the conductive polymer layer into a film.

<Crosslinking agent>
The crosslinking agent according to the present invention is used for crosslinking a water-soluble polymer or polymer latex that is a binder in the metal nanowire layer, and an aldehyde-based, epoxy-based, melamine-based, or isocyanate-based crosslinking agent can be used.

The method of applying the crosslinking agent is to apply the coating solution of the crosslinking agent on the transparent substrate in advance and dry it, and then apply the metal nanowire layer to it, or apply and dry the metal nanowire layer, A crosslinking agent may be applied there, or two layers of the metal nanowire dispersion and the crosslinking agent may be applied simultaneously, or a mixture of these may be applied and dried.

Moreover, the crosslinking agent solution may contain an acid, an alkali, or a salt as a pH adjuster, and is preferably an ammonia or ammonium salt because it can be easily removed by heating. Furthermore, it is preferable to heat at 100 to 150 ° C. in order to promote the crosslinking reaction.

<Patterning>
In the present invention, after forming a metal nanowire layer on a transparent support, or after forming a conductive polymer layer on the metal nanowire layer, the metal nanowire remover is patterned by an inkjet method, a screen, a gravure printing method, or the like. The conductive layer can be patterned by printing, photolithography, or the like. Alternatively, the metal nanowire layer or the conductive polymer layer may be directly patterned by an inkjet method, a gravure, a screen printing method, or the like.

<Metal nanowires>
In general, the metal nanowire refers to a linear structure having a metal element as a main component. In particular, the metal nanowire in the present invention means a structure in which a large number of linear structures having a diameter from the atomic scale to the nm size are formed in a mesh shape.

The metal nanowire according to 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 manufacturing method of Ag nanowire, 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 according to the present invention is not particularly limited, and polypyrrole, polyindole, polycarbazole, polythiophene (including substituted and unsubstituted polythiophene, the same applies hereinafter), polyaniline, polyacetylene, polyfuran, poly Chain conductive polymers such as paraphenylene 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 viewpoint of conductivity, transparency, and the like.

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 a 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 and the} like), or R ₄ P ⁺ (R═CH ₃ , C ₄ H ₉ , C ₆ H _{5 and the} like). 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. In addition, the transparent conductive composition of the present embodiment is 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 according to 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, and γ-butyrolactone. 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 according to 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.

<Transparent electrode>
The transparent electrode of the present invention is preferably highly smooth because the surface roughness of the conductive layer affects the performance of the EL element and the like. Specifically, the arithmetic average roughness Ra is Ra ≦ 5 nm. Is preferable, Ra ≦ 3 nm is more preferable, and Ra ≦ 1 nm is further more preferable. The maximum height Ry is preferably Ry ≦ 50 nm, more preferably Ry ≦ 40 nm, and further preferably Ry ≦ 30 nm.

In the transparent electrode of the present invention, the total light transmittance of the conductive layer containing metal nanowires is 60% or more, preferably 70% or more, particularly preferably 80% or more. The total light transmittance can be measured according to a known method using a spectrophotometer or the like.

In the transparent electrode of the present invention, the electrical resistance value of the conductive layer containing metal nanowires is preferably 10 ³ Ω / □ or less, more preferably 10 ² Ω / □ or less, as the surface specific resistance, It is particularly preferably 10Ω / □ or less. The surface specific resistance can be measured, for example, according to 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 is high, the metal nanowire-containing conductive layer Can be made uniform. The surface specific resistance of the conductive polymer is 10 ⁴ Ω / □ or more and 10 ⁹ Ω / □ or less, which can make the conductivity of the metal nanowire-containing conductive layer uniform without affecting current leakage between the metal nanowire-containing conductive layers. It is preferable that it is 10 ⁶ Ω / □ or more and 10 ⁹ Ω / □ or less.

An anchor coat or a hard coat can be applied to the transparent electrode of the present invention. If necessary, a conductive layer containing a conductive polymer or a metal oxide may be further provided.

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 paper, and electromagnetic wave shielding materials, etc., but has excellent conductivity and transparency. In addition, since it has high smoothness, it is preferably used for an organic EL device.

[Metal nanowire remover]
In the present invention, a pattern electrode is formed by pattern-printing a metal nanowire remover on a portion to be a non-pattern part of the conductive layer, and then performing a water washing treatment to remove the metal nanowire remover and the metal nanowire in the non-pattern part. can do.

As the composition of the metal nanowire remover according to the present invention, a bleach-fixing agent used for development processing of a silver halide color photographic light-sensitive material can be preferably used.

As a bleaching agent used in the bleach-fixing agent, a known bleaching agent can be used. In particular, an organic complex salt of iron (III) (for example, a complex salt of aminopolycarboxylic acids) or an organic compound such as citric acid, tartaric acid, malic acid, Acid, persulfate, hydrogen peroxide and the like are preferable.

Of these, organic complex salts of iron (III) are particularly preferred from the viewpoint of rapid processing and prevention of environmental pollution. Examples of aminopolycarboxylic acids useful for forming organic complex salts of iron (III), or salts thereof, include biodegradable ethylenediamine disuccinic acid (SS form), N- (2-carboxylate ethyl) -L-aspartic acid, β-alanine diacetic acid, methyliminodiacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, 1,3-diaminopropanetetraacetic acid, propylenediaminetetraacetic acid, nitrilotriacetic acid, cyclohexanediaminetetraacetic acid, iminodiacetic acid In addition to glycol ether diamine tetraacetic acid, compounds represented by general formula (I) or (II) of European Patent 0789275 can be mentioned. These compounds may be sodium, potassium or ammonium salts. Among these compounds, ethylenediamine disuccinic acid (SS form), N- (2-carboxylateethyl) -L-aspartic acid, β-alanine diacetic acid, ethylenediaminetetraacetic acid, 1,3-diaminopropanetetraacetic acid, methylimino The diacetic acid is preferably its iron (III) complex salt. These ferric ion complex salts may be used in the form of complex salts, and ferric salts such as ferric sulfate, ferric chloride, ferric nitrate, ferric ammonium sulfate, and ferric phosphate. And a chelating agent such as aminopolycarboxylic acid may be used to form a ferric ion complex salt in a solution. Moreover, you may use a chelating agent in excess rather than forming a ferric ion complex salt. Among the iron complexes, aminopolycarboxylic acid iron complexes are preferable, and the addition amount is 0.01 to 1.0 mol / liter, preferably 0.05 to 0.50 mol / liter, and more preferably 0.10 to 0. 50 mol / liter, more preferably 0.15 to 0.40 mol / liter.

Fixing agents used for the bleach-fixing agent are known fixing agents, that is, thiosulfates such as sodium thiosulfate and ammonium thiosulfate, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, ethylenebisthioglycolic acid, 3, These are water-soluble silver halide solubilizers such as thioether compounds such as 6-dithia-1,8-octanediol and thioureas, and these can be used alone or in combination. A special bleach-fixing agent comprising a combination of a fixing agent described in JP-A-55-155354 and a large amount of a halide such as potassium iodide can also be used. In the present invention, it is preferable to use thiosulfate, particularly ammonium thiosulfate. The amount of fixing agent per liter is preferably 0.3 to 2 mol, more preferably 0.5 to 1.0 mol.

The pH range of the bleach-fixing agent used in the present invention is preferably 3 to 8, and more preferably 4 to 7. In order to adjust the pH, hydrochloric acid, sulfuric acid, nitric acid, bicarbonate, ammonia, caustic potash, caustic soda, sodium carbonate, potassium carbonate and the like can be added as necessary.

Further, the bleach-fixing agent can contain various other antifoaming agents or surfactants, and organic solvents such as polyvinylpyrrolidone and methanol. Bleach fixers use sulfites (eg, sodium sulfite, potassium sulfite, ammonium sulfite, etc.), bisulfites (eg, ammonium bisulfite, sodium bisulfite, potassium bisulfite, etc.), metabisulfite as preservatives. Contains sulfite ion releasing compounds such as salts (for example, potassium metabisulfite, sodium metabisulfite, ammonium metabisulfite, etc.), arylsulfinic acids such as p-toluenesulfinic acid, m-carboxybenzenesulfinic acid, and the like. Is preferred. These compounds are preferably contained in an amount of about 0.02 to 1.0 mol / liter in terms of sulfite ion or sulfinate ion.

As a preservative, in addition to the above, ascorbic acid, a carbonyl bisulfite adduct, or a carbonyl compound may be added. Furthermore, you may add a buffering agent, a chelating agent, an antifoamer, an antifungal agent, etc. as needed.

[Pattern printing]
The pattern printing of the composition containing the metal nanowire remover includes letterpress (letter) printing, stencil (screen) printing, lithographic (offset) printing, intaglio (gravure) printing, spray printing, and inkjet. Although a printing method such as a printing method can be used, the gravure printing method and the screen printing method are particularly preferable.

<Organic EL device>
The organic EL element in the present invention has the transparent electrode of the present invention. The organic EL element in the present invention uses the transparent electrode of the present invention as an anode, and the organic light-emitting layer and the cathode can be made of any material and configuration generally used in organic EL elements. The element configuration of the organic EL element is as follows: 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 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. it can.

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

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.

<< Preparation of transparent electrode >>
[Production of silver nanowires]
Adv. Mater. With reference to the methods described in 2002, 14, 833 to 837, silver nanowires were produced by the following method.

(Nucleation process)
While stirring 1000 ml of an ethylene glycol solution maintained at 170 ° C. in a 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, and 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 aqueous 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.

[Preparation of Transparent Electrode 101; Comparative Example 1]
Using a 100 μm thick polyethylene terephthalate film (hereinafter referred to as PET) subjected to corona discharge treatment as a support, carboxymethylcellulose (hereinafter referred to as CMC) as a binder is added to the prepared silver nanowire dispersion liquid at 25% per silver mass, and the amount of silver nanowires is added. Was applied using a spin coater so as to be 0.05 g / m ² and dried. Next, as a conductive polymer, Baytron PH510 (manufactured by HC Starck), which is a dispersion of PEDOT: PSS (polystyrene sulfonic acid) = 1: 2.5, is charged with the following surfactant (UL-1). It was added, applied with a spin coater so that the dry film thickness was 300 nm, and dried. This was cut into a 50 mm × 50 mm square to produce a transparent electrode 101.

[Preparation of Transparent Electrode 102; Comparative Example 2]
In the production of the transparent electrode 101, the same operation was performed except that polyvinyl alcohol PVA203 (manufactured by Kuraray Co., Ltd.) was used as the binder of the silver nanowire dispersion liquid to produce the transparent electrode 102.

[Preparation of transparent electrode 103; Invention 1]
In the production of the transparent electrode 101, 10% of the aldehyde-based crosslinking agent glyoxal per binder mass was added to the silver nanowire dispersion, and sulfuric acid and ammonia were added to adjust the pH to 7.3. Using this, spin coating was performed to form a silver nanowire layer. After heating this at 120 ° C. for 30 minutes, the same operation as the production of the transparent electrode 101 was performed to form a conductive polymer layer, and the transparent electrode 103 was produced.

[Preparation of Transparent Electrode 104; Present Invention 2]
Similar to the production of the transparent electrode 101, after the silver nanowire layer was formed, it was overcoated with a saturated solution so that the coating amount of the crosslinking agent glyoxal was 10% of the binder mass in the coating film. This was subjected to heat treatment and the formation of a conductive polymer layer in the same manner as the transparent electrode 103 to produce a transparent electrode 104.

[Preparation of transparent electrode 105; Invention 3]
In the production of the transparent electrode 104, a silver nanowire dispersion was applied after undercoating a crosslinking agent on the transparent support. After heat-treating this, a conductive polymer layer was formed, and a transparent electrode 105 was produced.

[Preparation of transparent electrode 106; Invention 4]
In the production of the transparent electrode 103, the same operation was performed except that the binder was changed to PVA203, and the transparent electrode 106 was produced.

[Preparation of transparent electrode 107; Invention 5]
In the production of the transparent electrode 105, the same operation was performed except that the binder was changed to PVA203, and the transparent electrode 107 was produced.

[Preparation of Transparent Electrode 108; Present Invention 6]
In the production of the transparent electrode 103, except that the binder is changed to PVA203, the crosslinking agent is an epoxy-based crosslinking agent EX512 (manufactured by Nagase ChemteX), and the conductive polymer is changed to PEDOT: PSS Denatron P-502S (manufactured by Nagase ChemteX). Performed the same operation to produce a transparent electrode 108.

[Preparation of Transparent Electrode 109; Present Invention 7]
In the production of the transparent electrode 103, the same operation was performed except that the binder was changed to hydroxypropylmethylcellulose (HPMC), the crosslinking agent was changed to melamine-based crosslinking agent Becamine M3 and Catalyst ACX (made by DIC), and the conductive polymer was changed to P-502S. The transparent electrode 109 was produced.

[Preparation of transparent electrode 110; Invention 8]
In the production of the transparent electrode 105, the same operation was performed except that the binder was HPMC, the cross-linking agent was Becamine M3 and Catalist ACX, and the conductive polymer was changed to PEDOT: PSS Denatron P-5002CW (manufactured by Nagase ChemteX). A transparent electrode 110 was produced.

[Preparation of Transparent Electrode 111; Present Invention 9]
In the production of the transparent electrode 110, the same operation was performed except that the cross-linking agent was changed to EX512, and the transparent electrode 111 was produced.

[Preparation of Transparent Electrode 112; Present Invention 10]
In the production of the transparent electrode 110, the same operation was performed except that the cross-linking agent was changed to glyoxal, and the transparent electrode 112 was produced.

[Preparation of transparent electrode 113; Invention 11]
In the production of the transparent electrode 101, a silver nanowire dispersion liquid in which the amount of CMC added as a binder is 5% and a thermosetting resin-containing PEDOT Denatron G-2001A (manufactured by Nagase ChemteX) is added as a binder is 20%. Was used to form a silver nanowire layer. This was heated and cured, and then P-5002CW was applied as a conductive polymer to produce a transparent electrode 113.

[Preparation of Transparent Electrode 114; Present Invention 12]
In the production of the transparent electrode 113, G-2001A was changed to PEDOT HC-W004 (manufactured by Shin-Etsu Polymer Co., Ltd.) containing UV curable resin, and the transparent electrode 114 was produced in the same manner except that the curing treatment was performed by UV irradiation. did.

[Preparation of transparent electrode 115; Invention 13]
In the production of the transparent electrode 101, 10% of the crosslinker EX512 per binder mass of the silver nanowire dispersion was undercoated on the transparent support, and then the silver nanowire dispersion was applied. Application was spin-coated in the same manner as the production of the transparent electrode 101. After heat treatment at 120 ° C. for 30 minutes, CMC is added to the following metal nanowire removal liquid BF-1, the viscosity is adjusted to 500 mPa · s, and gravure printing is applied using a plate having a 10 mm stripe pattern. After printing, it was left for 1 minute, washed with running water, and then dried at 120 ° C. for 10 minutes. Thereafter, a conductive polymer layer was produced in the same manner as the production of the transparent electrode 101. This was cut into a 50 mm × 50 mm square to produce a transparent electrode 106.

<Preparation of metal nanowire removal solution BF-1>
Ethylenediaminetetraacetic acid ferric ammonium 60g
Ethylenediaminetetraacetic acid 2g
Sodium metabisulfite 15g
70g ammonium thiosulfate
Maleic acid 5g
Finished to 1 L with pure water and adjusted to pH 5.5 with sulfuric acid or ammonia water, metal nanowire removal liquid BF-1 was prepared.

[Preparation of Transparent Electrode 116; Present Invention 14]
In the production of the transparent electrode 115, a solution in which the crosslinking agent EX512 was added at 10% per binder mass of the silver nanowire dispersion was spin-coated with a transparent support, and the binder of the silver nanowire dispersion was changed to PVA245 (Kuraray) (PH510 solid content A transparent electrode 116 was produced in the same manner as the production of the transparent electrode 115 except for changing to 10%). The metal nanowire removing liquid BF-1 is screen-printed using a plate having a 10 mm stripe pattern after adding CMC and adjusting the viscosity to 10,000 mPa · s.

The materials used were as follows: PET (polyethylene terephthalate film): Konica Minolta CMC (carboxymethylcellulose): Sigma Aldrich PEDOT (poly-3,4-ethylenediothiophene): H.M. C. Made by Starck (trade name: PH510)
PSS (polystyrene sulfonic acid): H.I. C. Stark PVA203 (polyvinyl alcohol): Kuraray Denatron P-502S (trade name of the above PEDOT and PSS mixture): Nagase ChemteX HPMC (hydroxypropylmethylcellulose): Sigma Aldrich Becamine M3 (melamine cross-linking agent) ): Catalyst ACX (resin catalyst) manufactured by DIC: Denatron P-5002CW (trade name of the above PEDOT and PSS mixture) manufactured by DIC: P-502S (trade name of the above PEDOT and PSS mixture) manufactured by Nagase ChemteX Corporation: EX512 (epoxy-based crosslinking agent Denacol) manufactured by Nagase ChemteX Corp .: P-5002CW manufactured by Nagase ChemteX Corp. (trade name of the above-mentioned PEDOT and PSS mixture): Denatron G- manufactured by Nagase ChemteX Corp. 001A (trade name of the PEDOT and PSS mixture): Nagase ChemteX Corporation HC-W004 (UV-curable resin containing electrically electrons polymer Sepurujida): Shin-Etsu Polymer Co., Ltd. [Measurement]
The smoothness Ra and Ry of the transparent electrodes 101 to 114 were evaluated by the following method.

(Surface roughness)
In the present invention, Ra and Ry representing the smoothness of the surface of the conductive layer mean Ra = arithmetic mean roughness and Ry = maximum height (the difference in height between the top and bottom of the surface), and JIS B601 (1994). It is a value according to the surface roughness specified in). In the present invention, for measurement of Ra and Ry, a commercially available atomic force microscope (AFM) can be used, and measurement was performed 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 20 μm and Z 2 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 1 Hz.

Table 1 shows the results of measurement and evaluation.

In Table 1,
Mix: Addition of cross-linking agent to silver nanowire dispersion OC: Overcoat cross-linking agent on silver nanowire layer UC: Undercoat cross-linking agent under silver nanowire layer and then form silver nanowire layer Heat: Curing with heat Perform UV: Curing is performed with ultraviolet light.

From Table 1, it can be seen that the transparent electrode of the present invention has excellent smoothness Ra and Ry.

<< Production of organic element (organic EL element) >>
Using the produced transparent electrodes 101 to 116 as the first electrode, organic EL elements 201 to 216 were produced in the following procedure, respectively.

<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 red dopant material Btp ₂ Ir (acac) is 1% by mass and the green dopant material Ir (ppy) ₃ is 2% with respect to polyvinylcarbazole (PVK) as the host material. % And blue dopant material FIr (pic) are mixed so as to be 3% by mass, respectively, and dissolved in 1,2-dichloroethane so that the total solid concentration of PVK and the three dopants is 1% by mass. The coating liquid for layer formation 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 was deposited as a second electrode forming material under a vacuum of 5 × 10 ⁻⁴ Pa 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. Apply the adhesive around the second electrode except for the end so that the external lead terminals of the first electrode and the second electrode can be formed, paste the flexible sealing member, and then cure the adhesive by heat treatment It was.

[Light emission brightness unevenness]
Using a source measure unit type 2400 manufactured by KEITHLEY, a direct current voltage was applied to the produced organic EL elements 201 to 216 to emit light. About each organic EL 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. The evaluation results are shown in Table 2.

◎: 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.

As can be seen from Table 2, when the transparent electrode of the present invention is used as an electrode of an organic EL element, it can be seen that there is little light emission luminance unevenness.

Claims

In a transparent electrode having a conductive layer composed of a metal nanowire layer and a conductive polymer layer on a transparent support, a cross-linked product of a water-soluble polymer, a cross-linked product of a polymer latex, and a curable resin in the metal nanowire layer A transparent electrode comprising at least one selected from the cured products.
The transparent electrode according to claim 1, wherein the water-soluble polymer is polyvinyl alcohol or a cellulose derivative.
The water-soluble polymer cross-linked product or polymer latex cross-linked product is cross-linked with at least one cross-linking agent selected from aldehyde, melamine, epoxy, and isocyanate cross-linking agents. The transparent electrode according to claim 1, wherein the transparent electrode is provided.
The transparent electrode according to claim 1, 2, or 3, wherein the metal nanowire of the metal nanowire layer is a silver nanowire.
The method for producing a transparent electrode according to any one of claims 1 to 4, wherein the transparent electrode forms a metal nanowire layer comprising metal nanowires and a binder on a transparent support, and then the metal nanowire layer is formed. A method for producing a transparent electrode, which is produced by crosslinking or curing a binder and then forming a conductive polymer layer.
The method for producing a transparent electrode according to claim 5, wherein the binder is contained in a dispersion for forming the metal nanowire layer.
An organic electroluminescence device comprising the transparent electrode according to any one of claims 1 to 4.