WO2011077804A1

WO2011077804A1 - Transparent electrode and organic electronic device

Info

Publication number: WO2011077804A1
Application number: PCT/JP2010/067218
Authority: WO
Inventors: 孝敏末松; 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: 2009-12-22
Filing date: 2010-10-01
Publication date: 2011-06-30

Abstract

Provided is a transparent electrode which has high transparency, high smoothness, high conductivity, high flexibility and good water resistance and is usable in organic electronic devices such as organic EL devices and organic solar batteries. The transparent electrode comprises a flexible transparent substrate and a transparent conductive layer, which comprises a conductive polymer and binder(s), formed on said flexible transparent substrate, characterized in that said binder in the transparent conductive layer has a self-crosslinked structure or said binder and said conductive polymer together have a crosslinked structure, said binder is a polymer (A) represented by general formula (A), and the nanoindentation modulus of said transparent conductive layer is 4 GPa to 10 GPa inclusive. Also provided is an organic electronic device using said transparent electrode.

Description

Transparent electrodes and organic electronic devices

The present invention relates to a transparent electrode and an organic electronic device, and more particularly to a transparent electrode excellent in smoothness, conductivity, transparency, flexibility and water resistance, and an organic electronic device using the transparent electrode.

In recent years, with the increasing demand for thin TVs, various types of display technologies such as liquid crystal, plasma, organic EL, and field emission have been actively developed. The transparent electrode is an indispensable constituent technology even in various displays having different display methods. In addition to TVs, transparent electrodes are an indispensable technical element in touch panels, mobile phones, electronic paper, various solar cells, and various electroluminescence light control elements. In particular, in organic electronic device applications such as organic EL and organic thin-film solar cells, current leakage due to irregularities on the surface of the transparent electrode and distortion of layer formation are likely to cause light emission failure, power generation failure, etc. A high degree of smoothness is required.

Transparent electrodes used in organic electronic devices such as organic EL and organic thin-film solar cells are metal oxides typified by indium-tin composite oxide (ITO) films on substrates such as glass and transparent plastic films. Is mainly used. However, since the transparent electrode using a metal oxide is inferior in flexibility, there is a problem that a minute crack is formed on the surface of the transparent electrode when bending is repeated.

As a method of solving this problem, a method of forming a transparent conductor layer by coating or printing using a coating solution in which a conductive polymer typified by a π-conjugated polymer is dissolved or dispersed in an appropriate solvent (see Patent Document 1) ) Has been proposed. However, in this method, although flexibility is improved as compared with the ITO electrode, there is a problem that transparency and conductivity are remarkably lowered. In addition, when the conductive polymer layer is washed with water for the purpose of removing foreign substances or impurities, there is a problem that smoothness is impaired due to swelling or dissolution of the conductive polymer layer.

Also known is a method of laminating a conductive polymer on an ITO electrode in order to improve the smoothness of the ITO electrode (see Patent Document 2). However, in this configuration, if there are protrusions such as impurities on the ITO electrode, the elasticity of the conductive polymer layer is low. Therefore, when the electrode is bent, the conductive polymer layer is deformed together with the protrusions, and the organic electronic device It causes malfunction. Moreover, when the conductive polymer layer is thickened to prevent this, the transparency of the transparent electrode is impaired, and it is difficult to achieve both of them.

On the other hand, a method for producing a transparent conductive layer made of a conductive polymer and a non-aqueous binder on the ITO electrode (see Patent Document 3) has been proposed. By adding a non-aqueous binder, the strength and thickness of the transparent conductive layer necessary to supplement the flexibility of the ITO electrode can be obtained without impairing the transparency, but the conductivity of the transparent conductive layer can be reduced by reducing the conductive polymer ratio. There has been a problem that the performance is significantly reduced. Further, in Patent Document 3, since the binder is non-aqueous, impurities in the binder cannot be removed by washing with water, and there is a problem that the function of the organic electronic device is deteriorated.

JP-A-6-273964 JP 2003-45665 A Special table 2008-533701 gazette

This invention is made | formed in view of the said subject, The objective of this invention is transparency, smoothness, electroconductivity, flexibility which can be used for organic electronic devices, such as an organic EL element and an organic solar cell, An object of the present invention is to provide a transparent electrode excellent in water resistance and an organic electronic device using the transparent electrode. In particular, it is to provide a transparent electrode excellent in flexibility and an organic electronic device using the transparent electrode by controlling the nanoindentation elastic modulus of the transparent conductive layer.

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

1. In a transparent electrode having a transparent conductive layer comprising a conductive polymer and a binder on a flexible transparent substrate, the binders of the transparent conductive layer have a crosslinked structure, or the binder and the conductive polymer Has a crosslinked structure, the binder is a polymer (A) represented by the following general formula (A), and the nano-indentation elastic modulus of the transparent conductive layer is 4 GPa or more and 10 GPa or less. Transparent electrode.

(In the formula, X ¹ to X ³ each independently represents a hydrogen atom or a methyl group, and R ¹ to R ³ each independently represents an alkylene group having 5 or less carbon atoms. (Mol%), and 50 ≦ l + m + n ≦ 100.)
2. 2. The transparent electrode according to 1 above, wherein the transparent conductive layer has a nanoindentation elastic modulus of 5.5 GPa to 7.0 GPa.

3. 3. The transparent electrode according to 1 or 2, wherein the conductive polymer is a conductive polymer having a π-conjugated conductive polymer component and a polyanion component.

4. 4. The transparent electrode as described in 3 above, wherein the polyanion component is polysulfonic acid.

5. 5. An organic electronic device using the transparent electrode according to any one of 1 to 4 above.

ADVANTAGE OF THE INVENTION According to this invention, the transparent electrode excellent in transparency, smoothness, electroconductivity, flexibility, and water resistance which can be used for organic electronic devices, such as an organic EL element and an organic solar cell, and this transparent electrode are used. It is to provide an organic electronic device. In particular, by controlling the nanoindentation elastic modulus of the transparent conductive layer, it is possible to provide a transparent electrode excellent in flexibility and an organic electronic device using the transparent electrode.

Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to these.

In the transparent electrode having a transparent conductive layer comprising a conductive polymer and a binder on a flexible transparent substrate, the binder of the transparent conductive layer has a crosslinked structure, or the binder and the The conductive polymer has a crosslinked structure, the binder is the polymer (A) represented by the general formula (A), and the nanoindentation elastic modulus of the transparent conductive layer is 4 GPa or more and 10 GPa or less. It is characterized by being.

In the present invention, in particular, the binder of the transparent conductive layer or the conductive polymer and the binder are cross-linked, the binder is the polymer (A), and the nano-indentation elastic modulus of the transparent conductive layer is 4 GPa or more. By being 10 GPa or less, a transparent electrode excellent in transparency, smoothness, conductivity, flexibility, and water resistance can be obtained.

Further, in the present invention, a conductive polymer having a π-conjugated conductive polymer component and a polyanion component is used as the conductive polymer, and the polymer (A) is used as the binder, so that more transparent, conductive A transparent electrode having excellent properties can be obtained.

Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail.

[Conductive polymer]
The conductive polymer of the present invention is a conductive polymer having a π-conjugated conductive polymer component and a polyanion component.

Such a conductive polymer can be easily produced by chemical oxidative polymerization of a precursor monomer that forms a π-conjugated conductive polymer described later in the presence of an appropriate oxidizing agent, an oxidation catalyst, and a poly anion described later. .

[Π-conjugated conductive polymer]
The π-conjugated conductive polymer used in the present invention is not particularly limited, and includes polythiophenes (including basic polythiophenes, the same applies hereinafter), polypyrroles, polyindoles, polycarbazoles, polyanilines, polyacetylenes, polyfurans. , Polyparaphenylene vinylenes, polyazulenes, polyparaphenylenes, polyparaphenylene sulfides, polyisothianaphthenes, polythiazyl chain conductive polymers can be used. Of these, polythiophenes and polyanilines are preferable from the viewpoints of conductivity, transparency, stability, and the like. Most preferred is polyethylene dioxythiophene.

[Π-conjugated conductive polymer precursor monomer]
Precursor monomers used in the formation of π-conjugated conductive polymers have a π-conjugated system in the molecule, and even when polymerized by the action of an appropriate oxidant, a π-conjugated system is formed in the main chain. It is what is done. Examples thereof include pyrroles and derivatives thereof, thiophenes and derivatives thereof, anilines and derivatives thereof, and the like.

Specific examples of the precursor monomer include pyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-n-propylpyrrole, 3-butylpyrrole, 3-octylpyrrole, 3-decylpyrrole, 3-dodecylpyrrole, 3 , 4-dimethylpyrrole, 3,4-dibutylpyrrole, 3-carboxylpyrrole, 3-methyl-4-carboxylpyrrole, 3-methyl-4-carboxyethylpyrrole, 3-methyl-4-carboxybutylpyrrole, 3-hydroxy Pyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-butoxypyrrole, 3-hexyloxypyrrole, 3-methyl-4-hexyloxypyrrole, thiophene, 3-methylthiophene, 3-ethylthiophene, 3-propylthiophene, 3-Butylthiophene, 3-hexyl Thiophene, 3-heptylthiophene, 3-octylthiophene, 3-decylthiophene, 3-dodecylthiophene, 3-octadecylthiophene, 3-bromothiophene, 3-chlorothiophene, 3-iodothiophene, 3-cyanothiophene, 3-phenyl Thiophene, 3,4-dimethylthiophene, 3,4-dibutylthiophene, 3-hydroxythiophene, 3-methoxythiophene, 3-ethoxythiophene, 3-butoxythiophene, 3-hexyloxythiophene, 3-heptyloxythiophene, 3- Octyloxythiophene, 3-decyloxythiophene, 3-dodecyloxythiophene, 3-octadecyloxythiophene, 3,4-dihydroxythiophene, 3,4-dimethoxythiophene, 3,4-diethoxythione Phen, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-dihexyloxythiophene, 3,4-diheptyloxythiophene, 3,4-dioctyloxythiophene, 3,4-didecyloxy Thiophene, 3,4-didodecyloxythiophene, 3,4-ethylenedioxythiophene, 3,4-propylenedioxythiophene, 3,4-butenedioxythiophene, 3-methyl-4-methoxythiophene, 3-methyl -4-ethoxythiophene, 3-carboxythiophene, 3-methyl-4-carboxythiophene, 3-methyl-4-carboxyethylthiophene, 3-methyl-4-carboxybutylthiophene, aniline, 2-methylaniline, 3-isobutyl Aniline, 2-anilinesulfonic acid, 3-aniline Examples thereof include phosphorus sulfonic acid.

[Poly anion]
The polyanions used in the present invention are substituted or unsubstituted polyalkylene, substituted or unsubstituted polyalkenylene, substituted or unsubstituted polyimide, substituted or unsubstituted polyamide, substituted or unsubstituted polyester, It is a combination, and consists of a structural unit having an anionic group and a structural unit having no anionic group.

This poly anion is a solubilized polymer that solubilizes the π-conjugated conductive polymer in a solvent.

Also, the anion group of the polyanion functions as a dopant for the π-conjugated conductive polymer, and improves the conductivity and heat resistance of the π-conjugated conductive polymer.

The anion group of the polyanion may be any functional group capable of causing chemical oxidation doping to the π-conjugated conductive polymer. Among them, from the viewpoint of ease of production and stability, a monosubstituted sulfate ester Group, monosubstituted phosphate group, phosphate group, carboxy group, sulfo group and the like are preferable. Furthermore, from the viewpoint of the doping effect of the functional group on the π-conjugated conductive polymer, a sulfo group, a monosubstituted sulfate group, and a carboxy group are more preferable.

Specific examples of polyanions include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly-2-acrylamido-2-methylpropane sulfonic acid, poly Isoprene sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid, polymethacryl carboxylic acid, poly-2-acrylamido-2-methylpropane carboxylic acid, polyisoprene carboxylic acid, polyacrylic acid, etc. Can be mentioned. These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient.

Further, it may be a polyanion further having F (fluorine atom) in the compound. Specifically, Nafion (manufactured by Dupont) containing a perfluorosulfonic acid group, Flemion (manufactured by Asahi Glass Co., Ltd.) made of perfluoro vinyl ether containing a carboxylic acid group, and the like can be mentioned.

Among these, when the compound having a sulfonic acid is formed by applying and drying the conductive polymer-containing layer, it is crosslinked when heated at a temperature of 100 ° C. or more and 200 ° C. or less for 5 minutes or more. Since the reaction is accelerated, the washing resistance and solvent resistance of the coating film are remarkably improved, which is particularly preferable.

Further, among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylic acid ethyl sulfonic acid, and polybutyl acrylate sulfonic acid are preferable. These poly anions have high compatibility with the binder, and can further increase the conductivity of the obtained conductive polymer.

The degree of polymerization of the polyanion is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of solvent solubility and conductivity.

Examples of the method for producing a polyanion include a method of directly introducing an anionic group into a polymer having no anionic group using an acid, a method of sulfonating a polymer having no anionic group with a sulfonating agent, an anionic group A method of producing by polymerization of the containing polymerizable monomer may be mentioned.

Examples of the method for producing an anion group-containing polymerizable monomer by polymerization include a method for producing an anion group-containing polymerizable monomer in a solvent by oxidative polymerization or radical polymerization in the presence of an oxidizing agent and / or a polymerization catalyst. Specifically, a predetermined amount of the anionic group-containing polymerizable monomer is dissolved in a solvent, kept at a constant temperature, and a solution in which a predetermined amount of an oxidizing agent and / or a polymerization catalyst is dissolved in the solvent is added to the predetermined amount. React with time. The polymer obtained by the reaction is adjusted to a certain concentration by the solvent. In this production method, an anionic group-containing polymerizable monomer may be copolymerized with a polymerizable monomer having no anionic group.

The oxidizing agent, oxidation catalyst, and solvent used in the polymerization of the anionic group-containing polymerizable monomer are the same as those used in the polymerization of the precursor monomer that forms the π-conjugated conductive polymer.

When the obtained polymer is a polyanionic salt, it is preferably transformed into a polyanionic acid. Examples of the method for converting to an anionic acid include an ion exchange method using an ion exchange resin, a dialysis method, an ultrafiltration method, and the like. Among these, the ultrafiltration method is preferable from the viewpoint of easy work.

Such a conductive polymer is preferably a commercially available material. For example, a conductive polymer (abbreviated as PEDOT-PSS) composed of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid is described in H.C. C. It is commercially available from Starck as the Clevios series, from Aldrich as PEDOT-PSS 483095 and 560596, and from Nagase Chemtex as the Denatron series. Polyaniline is also commercially available from Nissan Chemical as the ORMECON series. In the present invention, such an agent can also be preferably used.

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 at least one selected from dimethyl sulfoxide, ethylene glycol, and diethylene glycol is preferably used.

[binder]
The binder of the present invention is characterized in that a transparent conductive layer is formed together with a conductive polymer, and the binder is crosslinked with each other, or at least a part of the binder and the conductive polymer has a crosslinked structure.

As a result, even if the water washing process is performed, the water washing process can be performed without dissolving or swelling the film, foreign matters on the film and impurities in the film can be removed, and current leakage of the organic electronic device can be suppressed. , Can improve the lifetime.

Furthermore, a cross-linking agent may be included in the cross-linking of the binders or between the binder and the conductive polymer, and the cross-linking agent is compatible with the resin and is not particularly limited as long as it forms a cross-linked structure. For example, an oxazoline crosslinking agent, a carbodiimide crosslinking agent, a blocked isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a formaldehyde crosslinking agent, or the like can be used alone or in combination.

In the present invention, the binder is the above polymer (A), but it is preferable that the anionic component of the conductive polymer is a polysulfonic acid group because the polymer (A) has a large effect of assisting the conductivity. It is an aspect.

The transparent conductive layer according to the present invention may contain a binder other than the polymer (A) as a binder as long as the effects of the present invention are not impaired. Examples of the binder other than the polymer (A) include polyester resins, acrylic resins, polyurethane resins, acrylic urethane resins, polycarbonate resins, cellulose resins, and polyvinyl acetal resins.

Moreover, the crosslinking can be measured by a change in glass transition temperature and nanoindentation elastic modulus of the transparent conductive layer, and a change in functional group by FTIR measurement.

[Nanoindentation elastic modulus]
The nanoindentation elastic modulus in the present invention is a method of calculating an elastic modulus from the degree of dent of a needle by pressing a minute needle against the transparent conductive layer with a constant load.

In the present invention, a value obtained by measuring a transparent conductive layer produced on a glass substrate is defined as a nanoindentation elastic modulus.

By setting the nanoindentation elastic modulus of the transparent conductive layer in the present invention to 10 GPa or less, the transparent conductive layer can have appropriate stretchability, and even if the transparent electrode is repeatedly bent, the transparent conductive layer surface is cracked. It does not occur and the smoothness of the surface of the transparent conductive layer can be maintained.

On the other hand, by setting the nano-indentation elastic modulus of the transparent conductive layer to 4 GPa or more, even if protrusions such as impurities are present on the auxiliary electrode such as an ITO electrode, when the electrode is bent, the transparent conductive material around the protrusions is transparent. Layer deformation can be prevented.

On the contrary, when the nano-indentation elastic modulus of the transparent conductive layer is 4 GPa or less, if there are protrusions such as impurities on the auxiliary electrode, the conductivity of the conductive polymer layer is low. The layer is deformed and causes a malfunction of the organic electronic device. The nanoindentation elastic modulus of the transparent conductive layer is preferably 5.5 GPa or more and 7.0 GPa or less.
(Measurement of nanoindentation elastic modulus)
The nanoindentation elastic modulus can be measured as follows.

Using a Triscope made by Hystron, it was mounted on SPI3800N made by SII Nano Technology and measured.

In the measurement, a triangular pyramid diamond indenter called a Belkovic indenter (tip ridge angle 142.3 °) having an edge curvature radius of 75 to 100 nm was used.

¡Apply gradually to the surface at a right angle and apply gradually, and gradually return the load to 0 after reaching the maximum load.

A value P / A obtained by dividing the maximum load P at this time by the projected area A of the indenter contact portion is calculated as hardness, and this value (hardness = P / A (GPa)) is used as an index representing the nanoindentation elastic modulus. Show.

[Polymer (A)]
The polymer (A) according to the present invention is a polymer (A) represented by the general formula (A). In general formula (A), X ¹ to X ³ each independently represents a hydrogen atom or a methyl group, and R ¹ to R ³ each independently represents an alkylene group having 5 or less carbon atoms. l, m, and n represent the composition ratio (mol%), and 50 ≦ l + m + n ≦ 100.

The polymer (A) according to the present invention is a polymer (A) represented by the general formula (A), and the main copolymerization component is a monomer (repeating unit) 1 to 3 represented by the following general formulas 1 to 3. The component of 50 mol% or more of the copolymer component is any of the monomers 1 to 3 represented by the following general formulas 1 to 3, or the components of the monomers 1 to 3 represented by the following general formulas 1 to 3. A copolymer having a total of 50 mol% or more is preferred. More preferably, the total of the components of the monomers 1 to 3 represented by the following general formulas 1 to 3 is 80 mol% or more, and further any one of the monomers 1 to 3 represented by the following general formulas 1 to 3 It is also a preferred embodiment. That is, in the general formula (A), 0 ≦ l ≦ 100, 0 ≦ m ≦ 100, and 0 ≦ n ≦ 100.

(In the formula, X ¹ to X ³ each independently represents a hydrogen atom or a methyl group. R ¹ to R ³ each independently represents an alkylene group having 5 or less carbon atoms.)
In the polymer (A), other monomer components may be copolymerized, but a monomer component having high hydrophilicity is more preferable.

The polymer (A) preferably has a number average molecular weight of 0 to 5% by mass with a molecular weight of 1000 or less. When the amount of the low molecular component is small, it is possible to further reduce the storage stability of the device and the behavior of having a barrier in the direction perpendicular to the layer when exchanging charges in the direction perpendicular to the conductive layer.

In the number average molecular weight of the polymer (A), the content of the molecular weight of 1000 or less is 0 to 5% by mass or less. For example, a redispersion method or preparative GPC is synthesized by synthesizing a monodisperse polymer by living polymerization. A method of removing the low molecular weight component or suppressing the generation of the low molecular weight component can be used. In the reprecipitation method, the polymer is dissolved in a solvent in which the polymer can be dissolved and dropped into a solvent having a lower solubility than the solvent in which the polymer is dissolved, thereby precipitating the polymer and removing low molecular weight components such as monomers, catalysts, and oligomers. It is a method to do. In addition, preparative GPC is, for example, recycled preparative GPCLC-9100 (manufactured by Nippon Analytical Industrial Co., Ltd.), polystyrene gel column, and a polymer-dissolved solution can be separated by molecular weight to cut the desired low molecular weight. This is how you can do it. In the living polymerization, the generation of the starting species does not change with time, and there are few side reactions such as termination reaction, and a polymer having a uniform molecular weight can be obtained. Since the molecular weight can be adjusted by the addition amount of the monomer, for example, if a polymer having a molecular weight of 20,000 is synthesized, the formation of a low molecular weight body can be suppressed. From the viewpoint of production suitability, reprecipitation and living polymerization are preferred.

The number average molecular weight and molecular weight distribution of the binder of the present invention can be measured by generally known gel permeation chromatography (GPC). The solvent to be used is not particularly limited as long as the water-soluble binder dissolves, and THF, DMF, and CH ₂ Cl ₂ are preferable, THF and DMF are more preferable, and DMF is more preferable. The measurement temperature is not particularly limited, but 40 ° C. is preferable.

The number average molecular weight of the polymer (A) of the present invention is preferably in the range of 3,000 to 2,000,000, more preferably 4,000 to 500,000, still more preferably in the range of 5,000 to 100,000.

The molecular weight distribution of the polymer (A) of the present invention is preferably 1.01 to 1.30, more preferably 1.01 to 1.25. The molecular weight distribution is represented by a ratio of (weight average molecular weight / number average molecular weight).

The content with a molecular weight of 1000 or less was converted to a ratio by integrating the area with a molecular weight of 1000 or less and dividing by the area of the entire distribution in the distribution obtained by GPC.

The living radical polymerization solvent is inactive under reaction conditions and is not particularly limited as long as it can dissolve the monomer and the polymer to be formed, but a mixed solvent of an alcohol solvent and water is preferable. The living radical polymerization temperature varies depending on the initiator used, but is generally -10 to 250 ° C, preferably 0 to 200 ° C, more preferably 10 to 100 ° C.

In the present invention, in order to set the nanoindentation elastic modulus of the transparent conductive layer to 4 GPa or more and 10 GPa or less, the ratio of the conductive polymer and the polymer (A) in the transparent conductive layer is adjusted, and the coating liquid containing these in the flexible transparent substrate After coating, a drying process or a heat treatment may be performed at 100 ° C to 200 ° C.

In particular, the ratio of the content of the conductive polymer to the polymer (A) (conductive polymer / polymer (A) (mass ratio)) is approximately 10/90 to 70/30 and dried at the above temperature, The elastic modulus can be within the range of the present invention.

Furthermore, as the drying temperature, the above elastic modulus range can be easily set within the range of the present invention by setting the above ratio to the range of 120 ° C. to 150 ° C.

In the present invention, when the ratio of the polymer (A) to the conductive polymer is 30% or less, the amount of the conductive polymer in the transparent conductive layer is increased, and the value of the nanoindentation elastic modulus is 4.0 or less. Transparency is also impaired. Further, when the ratio of the polymer (A) to the conductive polymer is 900% or more, the amount of the polymer (A) in the transparent conductive layer increases, the value of the nanoindentation elastic modulus becomes 10.0 or more and the conductive property is increased. Sexuality gets worse.
[Transparent conductive layer]
In the present invention, the transparent conductive layer can be formed by applying and drying a liquid mixture comprising at least a conductive polymer and a binder on a transparent substrate or a transparent substrate having an auxiliary electrode. The concentration of the solid content in the coating solution is preferably from 0.5% by mass to 30% by mass, and from 1 to 20% by mass is the stagnation stability of the solution, the smoothness of the coating film, and the leakage. It is more preferable from the viewpoint of the prevention effect.

Coating methods include roll coating, bar coating, dip coating, spin coating, casting, die coating, blade coating, gravure coating, curtain coating, spray coating, doctor coating, letterpress (letterpress) ) Printing method, stencil (screen) printing method, lithographic (offset) printing method, intaglio (gravure) printing method, spray printing method, inkjet printing method and the like can be used.

The dry film thickness of the conductive polymer-containing layer is preferably 30 nm to 2000 nm. The conductive layer of the present invention preferably has a thickness of 100 nm or more because the decrease in conductivity is large in the region of less than 100 nm, and more preferably 200 nm or more from the viewpoint of further improving the leakage prevention effect. Further, it is more preferably 1000 nm or less from the viewpoint of maintaining high transmittance.

In particular, when the polyanion is polysulfonic acid, it is preferable to perform additional heat treatment for 5 minutes or more at a temperature of 100 ° C. or higher and 200 ° C. or lower after the coating and drying. Thereby, the washing | cleaning tolerance and solvent tolerance of a transparent conductive layer can be improved significantly. Moreover, the preservability of the organic electronic device using this transparent conductive layer can be improved. A temperature of 100 ° C. or higher is preferable from the viewpoint of achieving the above effect, and a temperature of 200 ° C. or lower is preferable from the viewpoint of suppressing the other reaction and achieving the above effect. The treatment temperature is more preferably 110 ° C. or more and 180 ° C. or less, and the treatment time is more preferably 15 minutes or more. There is no particular upper limit for the treatment time, but it is preferably 120 minutes or less in view of productivity.

Further, from the viewpoint of wettability, the transparent conductive layer may be subjected to surface treatment, and conventionally known techniques can be used for the surface treatment. For example, the surface treatment includes surface activation treatment such as corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment.
[Transparent electrode]
In the present invention, the transparent electrode having a transparent conductive layer composed of at least a conductive polymer and a binder is at least formed of a transparent conductive layer comprising the conductive polymer of the present invention and a binder alone, or As an auxiliary electrode, the transparent conductive layer of the present invention is laminated on other known conductive electrode layers such as ITO and ZnO, or a stripe-like, mesh-like or random mesh-like electrode described later. The transparent conductive layer of the present invention is laminated, or the transparent conductive layer of the present invention includes a striped, mesh, or random mesh electrode at least partially embedded. However, if the transparent electrode contains a transparent conductive layer comprising at least a conductive polymer and a binder, Not Jowa.
[Auxiliary electrode]
In order to cope with an increase in area, the electrode having the transparent conductive layer of the present invention preferably further includes an auxiliary electrode composed of a light-impermeable conductive portion and a light-transmitting window portion.

The light-opaque conductive portion of the auxiliary electrode is preferably a metal from the viewpoint of good conductivity, and examples of the metal material include gold, silver, copper, iron, nickel, and chromium. The metal of the conductive part may be an alloy, and the metal layer may be a single layer or a multilayer.

The shape of the auxiliary electrode is not particularly limited, but, for example, the conductive portion has a stripe shape, a mesh shape, or a random mesh shape. There are no particular limitations on the method of forming the stripe-shaped or mesh-shaped auxiliary electrode with the conductive portion, and a conventionally known method can be used. For example, a metal layer can be formed on the entire surface of the substrate and formed by a known photolithography method. Specifically, a conductor layer is formed on the entire surface of the substrate using one or more physical or chemical forming methods such as vapor deposition, sputtering, and plating, or a metal foil is formed with an adhesive. After being laminated on the material, it can be processed into a desired stripe shape or mesh shape by etching using a known photolithography method.

As another method, a method of printing an ink containing metal fine particles in a desired shape by screen printing, or applying a plating catalyst ink to a desired shape by gravure printing or an ink jet method, followed by plating treatment As another method, a method using silver salt photographic technology can also be used. A method using silver salt photographic technology can be carried out, for example, referring to paragraph numbers (0076) to (0112) of JP2009-140750A and examples. The method for carrying out the plating process by gravure printing of the catalyst ink can be carried out with reference to, for example, JP-A-2007-281290.
(Random network structure)
As a random network structure, for example, a method for spontaneously forming a disordered network structure of conductive fine particles by applying and drying a liquid containing metal fine particles as described in JP-T-2005-530005 Can be used. As another method, for example, a method for forming a random network structure of metal nanowires by applying and drying a coating solution containing metal nanowires as described in JP-T-2009-505358 can be used.

Metal nanowire refers to a fibrous structure having a metal element as a main component. In particular, in the present invention, the metal nanowire means a number of fibrous structures having a minor axis from the atomic scale to the nm size.

As the metal nanowire, in order to form a long conductive path with one metal nanowire, the average length is preferably 3 μm or more, more preferably 3 to 500 μm, and particularly preferably 3 to 300 μm. In addition, the relative standard deviation of the length is preferably 40% or less. Moreover, although there is no restriction | limiting in particular in an average breadth, it is preferable that it is small from a transparency viewpoint, and the larger one is preferable from a conductive viewpoint. The average minor axis 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 minor axis is preferably 20% or less. The basis weight of the metal nanowire is preferably 0.005 g / m ² to 0.5 g / m ² , more preferably 0.01 g / m ² to 0.2 g / m ² .

As the metal used for the metal nanowire, copper, iron, cobalt, gold, silver or the like can be used, but silver is preferable from the viewpoint of conductivity. In addition, although a single metal may be used, in order to achieve both conductivity and stability (sulfurization, oxidation resistance, and migration resistance of metal nanowires), the main metal and one or more other metals May be included in any proportion.

There is no restriction | limiting in particular in the manufacturing method of metal nanowire, For example, well-known means, such as a liquid phase method and a gaseous-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 silver nanowires, Adv. Mater. , 2002, 14, 833-837; Chem. Mater. 2002, 14, 4736-4745, a method for producing gold nanowires is disclosed in Japanese Patent Application Laid-Open No. 2006-233252, a method for producing copper nanowires is disclosed in Japanese Patent Application Laid-Open No. 2002-266007, and the like. Reference can be made to 2004-149871. In particular, the above-described method for producing silver nanowires can be preferably applied because silver nanowires can be easily produced in an aqueous solution, and the conductivity of silver is maximum in metals.
[Washing treatment]
If there are foreign matter or impurities on the surface or inside of the transparent electrode, the performance such as the lifetime of the organic electronic device is greatly deteriorated. In the present invention, it is preferable to perform a water washing treatment. The water washing treatment in the present invention refers to washing the transparent conductive layer using a washing solution of an aqueous solvent. The aqueous solvent represents a solvent in which 50% by mass or more is water. Of course, pure water containing no other solvent may be used. Furthermore, it is desirable to use ultrapure water because there are few foreign substances in the cleaning liquid. The ultrapure water means water having a specific resistance of about 18 MΩ · cm and a total organic carbon TOC measured by a method according to JISK0551 of less than 0.05 mg / L when the water temperature is 25 ° C. The component other than water in the aqueous solvent is not particularly limited as long as it is a solvent compatible with water, but an alcoholic solvent can be preferably used, and isopropyl alcohol having a boiling point relatively close to water can be used. preferable. Furthermore, in order to improve the wettability of the transparent conductive layer, the cleaning liquid may contain a surfactant. Moreover, as long as the filter component does not elute, it is preferable that the cleaning solution is passed through various filters because foreign substances in the cleaning solution are reduced.
[Flexible transparent substrate]
The flexible transparent substrate used for the electrode of the present invention is not particularly limited as long as it has high light transmittance and excellent flexibility. For example, in terms of ease of forming a conductive layer on the surface, a resin substrate, a resin film, and the like are preferably mentioned. From the viewpoint of productivity and performance such as lightness and flexibility, a transparent resin film is used. It is preferable to use it.

In the present invention, the flexible transparent substrate is preferably a transparent resin film because it is flexible. If it is a transparent resin film, it is resistant to deformation and impact due to external force, and is difficult to break. There is no restriction | limiting in particular in the transparent resin film which can be used preferably, About the material, a shape, a structure, thickness, etc., it can select suitably from well-known things. For example, polyester resin films such as polyethylene terephthalate (PET), polyethylene naphthalate, modified polyester, polyethylene (PE) resin films, polypropylene (PP) resin films, polystyrene resin films, polyolefin resin films such as cyclic olefin resins, Vinyl resin films such as polyvinyl chloride and polyvinylidene chloride, polyether ether ketone (PEEK) resin film, polysulfone (PSF) resin film, polyether sulfone (PES) resin film, polycarbonate (PC) resin film, polyamide resin Film, polyimide resin film, acrylic resin film, triacetyl cellulose (TAC) resin film, and the like. If the resin film transmittance of 80% or more at 0 nm), can be preferably applied to a transparent resin film according to the present invention. Among these, from the viewpoint of transparency, heat resistance, ease of handling, strength and cost, it is preferably a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene naphthalate film, a polyethersulfone film, or a polycarbonate film, and biaxially stretched. More preferred are polyethylene terephthalate films and biaxially stretched polyethylene naphthalate films.

The transparent substrate used in the present invention can be subjected to a surface treatment or an easy adhesion layer in order to ensure the wettability and adhesion of the coating solution. A conventionally well-known technique can be used about a surface treatment or an easily bonding layer. For example, the surface treatment includes surface activation treatment such as corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment.

Also, examples of the easy adhesion layer include polyester, polyamide, polyurethane, vinyl copolymer, butadiene copolymer, acrylic copolymer, vinylidene copolymer, epoxy copolymer and the like. The easy adhesion layer may be a single layer, but may be composed of two or more layers in order to improve adhesion.

Further, an inorganic or organic film or a hybrid film of both may be formed on the front or back surface of the transparent substrate, and the water vapor transmission rate (25 ± 0) measured by a method in accordance with JIS K 7129-1992. .5 ° C., relative humidity (90 ± 2)% RH) is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less barrier film, and further conforms to JIS K 7126-1987 The oxygen permeability measured by the above method is 1 × 10 ⁻³ ml / m ² · 24 h · atm or less, the water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is 1 A high barrier film of × 10 ⁻³ g / (m ² · 24 h) or less is preferable.

As a material for forming a barrier film formed on the front or back surface of the transparent substrate in order to form a high barrier film, any material may be used as long as it has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

[Organic electronic devices]
The organic electronic device in the present invention has a first electrode and a second electrode facing each other on a substrate, and has at least one organic functional layer between the first electrode and the second electrode. In the present invention, at least one of the first electrode and the second electrode is an electrode including the transparent electrode layer of the present invention. Examples of the organic functional layer include, but are not limited to, an organic light emitting layer, an organic photoelectric conversion layer, and a liquid crystal polymer layer. The present invention is particularly effective when the functional layer is a thin film and an organic light emitting layer or an organic photoelectric conversion layer, which is a current-driven device.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, “part” or “%” in the examples represents “part by mass” or “% by mass”.

Example 1
[Binder of the present invention: synthesis of polymer (A)]
<Synthesis of Binder of the Present Invention: Polymer (A) by Living Radical Polymerization Using ATRP (Atom Transfer Radical Polymerization) Method>
“Synthesis of Initiator 1”
Synthesis Example 1 (Synthesis of Methoxycapped Oligoethylene Glycol 2-Bromoisobutyrate (Initiator 1))
2-Bromoisobutyryl bromide (7.3 g, 35 mmol), triethylamine (2.48 g, 35 mmol) and THF (20 ml) were added to a 50 ml three-necked flask, and the internal temperature was kept at 0 ° C. with an ice bath. In this solution, 30 ml of a 33% THF solution of oligoethylene glycol (10 g, 23 mmol, ethylene glycol units 7-8, manufactured by Laporte Specialties) was added dropwise. After stirring for 30 minutes, the solution was brought to room temperature and further stirred for 4 hours. After THF was removed under reduced pressure by a rotary evaporator, the residue was dissolved in diethyl ether and transferred to a minute funnel. Water was added and the ether layer was washed three times, and then the ether layer was dried with MgSO 4. The ether was distilled off under reduced pressure using a rotary evaporator to obtain 8.2 g (yield 73%) of initiator 1.

Synthesis Example 2 (Synthesis of poly (2-hydroxyethyl acrylate))
Initiator 1 (500 mg, 1.02 mmol), 2-hydroxyethyl acrylate (4.64 g, 40 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), 50:50 v / v% methanol / water mixed solvent 5 ml was put into a Schlenk tube, and the pressure was reduced. The Schlenk tube was immersed in the lower liquid nitrogen for 10 minutes. The Schlenk tube was taken out of liquid nitrogen and replaced with nitrogen after 5 minutes. After performing this operation three times, bipyridine (400 mg, 2.56 mmol) and CuBr (147 mg, 1.02 mmol) were added under nitrogen, and the mixture was stirred at 20 ° C. After 30 minutes, the reaction solution was dropped onto a 4 cm Kiriyama funnel with filter paper and silica, and the reaction solution was recovered under reduced pressure. The solvent was distilled off under reduced pressure using a rotary evaporator and then dried under reduced pressure at 50 ° C. for 3 hours. As a result, 2.60 g (yield 84%) of a water-soluble binder 1 having a number average molecular weight of 13100, a molecular weight distribution of 1.17, and a molecular weight of <1000 and a content of 0% by mass was obtained.

The structure and molecular weight were measured by ¹ H-NMR (400 MHz, manufactured by JEOL Ltd.) and GPC (Waters 2695, manufactured by Waters), respectively.
<GPC measurement conditions>
Apparatus: Wagers 2695 (Separations Module)
Detector: Waters 2414 (Refractive Index Detector)
Column: Shodex Asahipak GF-7M HQ
Eluent: Dimethylformamide (20 mM LiBr)
Flow rate: 1.0 ml / min
Temperature: 40 ° C
Synthesis Example 3 (Synthesis of poly (2-hydroxyethyl vinyl ether) and poly (2-hydroxyethyl acrylamide))
In Synthesis Example 2 (Synthesis of poly (2-hydroxyethyl acrylate)), except that 2-hydroxyethyl acrylate was replaced with a monomer corresponding to the polymer to be prepared, poly (2 -Hydroxyethyl vinyl ether), poly (2-hydroxyethylacrylamide), (number average molecular weight of about 20,000, molecular weight <1000% content by mass).
[Production of Substrate A (Flexible Transparent Substrate A and Glass Substrate A)]
<< Production of Substrate A (Flexible Transparent Substrate A) >>
A substrate A having a transparent gas barrier property (flexible transparent substrate A) in which three layers of a low density layer, a medium density layer, and a high density layer are laminated on a biaxially stretched PEN film using an atmospheric pressure plasma discharge treatment method. Produced.

As a result of measuring the water vapor permeability by a method based on JIS K 7129-1992, it was 10 ⁻³ g / (m ² · 24 h) or less. As a result of measuring oxygen permeability by a method according to JIS K 7126-1987, it was 10 ⁻³ ml / (m ² · 24 hr · MPa) or less.
<< Production of Substrate A (Glass Substrate A) >>
A glass substrate was prepared as substrate A (glass substrate A).
[Production of ITO substrate A (ITO flexible transparent substrate A and ITO glass substrate A)]
Photolithographic method is used on a substrate in which ITO (indium tin oxide) is deposited to a thickness of 150 nm by sputtering on the surface of the substrate A (flexible transparent substrate A) without the barrier layer and on the front surface of the substrate A (glass substrate A). After patterning, the substrate was immersed in isopropyl alcohol, and subjected to ultrasonic cleaning treatment for 10 minutes with an ultrasonic cleaner Bransonic 3510J-MT (manufactured by Nippon Emerson), and ITO substrate A (ITO flexible transparent substrate A, And ITO glass substrate A)).
[Production of silver nanowire substrate A (silver nanowire flexible transparent substrate A and silver nanowire glass substrate A)]
Further, the following silver nanowire dispersion liquid is applied to the surface of the substrate A (flexible transparent substrate A) without the barrier layer and the surface of the substrate A (glass substrate A), and the basis weight of the silver nanowire is 0.06 g / m. ^The silver nanowire dispersion liquid was applied using a bar coating method so as to be ² and dried and heated at 120 ° C. for 20 minutes. Thus, the metal fine particle removing solution was removed, and silver nanowire substrates A (silver nanowire flexible transparent substrate A and silver nanowire glass substrate A) were produced.
(Silver nanowire dispersion)
Silver nanowire dispersions are described in Adv. Mater. , 2002, 14, 833 to 837, using PVP K30 (number average molecular weight 50,000; manufactured by ISP) to produce silver nanowires having an average minor axis of 75 nm and an average length of 35 μm, After silver nanowires are filtered and washed using an ultrafiltration membrane, hydroxypropylmethylcellulose 60SH-50 (manufactured by Shin-Etsu Chemical Co., Ltd.) is redispersed in an aqueous solution containing 25% by mass of silver, and the silver nanowire dispersion liquid Was prepared.
(Metal particulate removal solution)
Further, the metal fine particle removing liquid having the following composition was used.

<Preparation of metal fine particle removal solution>
Ethylenediaminetetraacetic acid ferric ammonium 60g
Ethylenediaminetetraacetic acid 2.0 g
Sodium metabisulfite 15g
70g ammonium thiosulfate
Maleic acid 5.0g
Finished to 1 L with pure water, and adjusted to pH 5.5 with sulfuric acid or ammonia water, a metal fine particle removing solution was prepared. The viscosity of the metal fine particle removing liquid BF was adjusted to 10 Pa · s (10000 cP) with sodium carboxymethylcellulose (manufactured by SIGMA-ALDRICH; C5013, hereinafter abbreviated as CMC).
[Preparation of transparent conductive layer coating solutions A to O]
Transparent conductive layer coating liquids A to O, which are mixed liquids of the following conductive polymer and binder, were prepared.

(Preparation of transparent conductive layer coating solution A)
Conductive polymer / binder = 100/0 (mass ratio) mixed solution PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) (used alone)
(Preparation of transparent conductive layer coating solution B)
Mixed liquid of conductive polymer / binder = 5/95 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 0.265 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.475g
(Preparation of transparent conductive layer coating solution C)
Mixed liquid of conductive polymer / binder = 5/95 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 0.265 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.475g
Dimethyl sulfoxide 0.10g
(Preparation of transparent conductive layer coating solution D)
Mixed liquid of conductive polymer / binder = 10/90 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 0.529 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.45g
(Preparation of transparent conductive layer coating solution E)
Mixed liquid of conductive polymer / binder = 30/70 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 1.587 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.350g
(Preparation of transparent conductive layer coating solution F)
Conductive polymer / binder = 50/50 (mass ratio) mixed solution PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 2.645 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.250g
(Preparation of transparent conductive layer coating solution G)
Mixed liquid of conductive polymer / binder = 70/30 (mass ratio) PEDOT-PSS CLEVIOS, PH510 (solid content 1.89%)
(Manufactured by HC Starck) 3.704 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.150g
(Preparation of transparent conductive layer coating solution H)
Conductive polymer / binder = 80/20 (mass ratio) mixed solution PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 4.233 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.100g
(Preparation of transparent conductive layer coating liquid I)
Mixed liquid of conductive polymer / binder = 30/70 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 1.587 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.350g
Dimethyl sulfoxide 0.10g
(Preparation of transparent conductive layer coating solution J)
Mixed liquid of conductive polymer / binder = 30/70 (mass ratio) PEDOT-PSS CLEVIOS P AI 4083
(Solid content 1.5%) (manufactured by HC Starck) 2,000 g
Polyhydroxyethyl acrylate (Synthesis Example 2, 20% solid content aqueous solution)
0.350g
(Preparation of transparent conductive layer coating solution K)
Mixed liquid of conductive polymer / binder = 30/70 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 1.587 g
Polyhydroxyethyl vinyl ether (number average molecular weight 20,000, solid content 20% aqueous solution) 0.350 g
(Preparation of transparent conductive layer coating solution L)
Mixed liquid of conductive polymer / binder = 30/70 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 1.587 g
Polyhydroxyethylacrylamide (number average molecular weight 20,000, solid content 20% aqueous solution) 0.350 g
(Preparation of transparent conductive layer coating solution O)
Mixed liquid of conductive polymer / binder = 10/90 (mass ratio) PEDOT-PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 0.529 g
Polyvinyl alcohol PVA-235 (made by Kureha) 2% solid content aqueous solution 4.500 g
Dimethyl sulfoxide 0.100g
Epoxy-based crosslinking agent Denacol EX-313
(Nagase ChemteX Corporation) 0.500g
[Preparation of transparent electrode]
<< Preparation of ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1) >>
Using a spin coater, the transparent conductive layer coating liquid A was applied to the ITO substrate A (ITO flexible transparent substrate A and ITO glass substrate A) thus prepared so as to have a dry film thickness of 300 nm. After wiping off an unnecessary part, it heat-dried at 120 degreeC and 20 minutes, and was set as the ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1). About the ITO glass electrode 1, the transmittance | permeability, electroconductivity, nanoindentation elastic modulus, and the washing | cleaning tolerance were measured with the following method. Moreover, about the ITO flexible transparent electrode 1, operation which bend | folds 45 degrees inside and outside was performed 100 times, and the smoothness before and behind operation was measured.

<< Production of ITO electrode 2 (ITO flexible transparent electrode 2, ITO glass electrode 2) >>
The ITO electrode 2 (ITO flexible transparent electrode 2 and ITO glass electrode 2) was formed in the same manner as the ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1) except that the drying temperature was changed from 120 ° C to 150 ° C. The same measurement was performed.

(Production of ITO electrodes 3 and 4 (ITO flexible transparent electrodes 3 and 4 and ITO glass electrodes 3 and 4))
The same method as the ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1) except that the transparent conductive layer coating liquid A is changed to the transparent conductive layer coating liquids B and C and the drying temperature 120 ° C. is changed to 180 ° C. Then, ITO electrodes 3 and 4 (ITO flexible transparent electrodes 3 and 4 and ITO glass electrodes 3 and 4) were prepared, and the same measurement was performed.

<< Production of ITO electrodes 5 to 9 (ITO flexible transparent electrodes 5 to 9 and ITO glass electrodes 5 to 9) >>
The same method as that for the ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1) except that the transparent conductive layer coating solution A is changed to the transparent conductive layer coating solutions D to H and the drying temperature 120 ° C. is changed to 150 ° C. Then, ITO electrodes 5 to 9 (ITO flexible transparent electrodes 5 to 9, ITO glass electrodes 5 to 9) were prepared, and the same measurement was performed.
<< Production of ITO electrodes 10 to 14 (ITO flexible transparent electrodes 10 to 14 and ITO glass electrodes 10 to 14) >>
ITO electrodes 10 to 14 (ITO flexible) in the same manner as ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1) except that transparent conductive layer coating liquid A was changed to transparent conductive layer coating liquids D to H. Transparent electrodes 10 to 14 and ITO glass electrodes 10 to 14) were prepared and subjected to the same measurement.
<< Production of ITO electrodes 15 to 19 (ITO flexible transparent electrodes 15 to 19 and ITO glass electrodes 15 to 19) >>
Similar to ITO electrode 1 (ITO flexible transparent electrode 1 and ITO glass electrode 1), except that transparent conductive layer coating solution A was changed to transparent conductive layer coating solutions I to L and O, and drying temperature 120 ° C. was changed to 150 ° C. In this way, ITO electrodes 15 to 19 (ITO flexible transparent electrodes 15 to 19 and ITO glass electrodes 15 to 19) were prepared and subjected to the same measurement.

<< Preparation of Silver Nanowire Electrodes 20-27 (Silver Nanowire Flexible Transparent Electrodes 20-27 and Silver Nanowire Glass Electrodes 20-27) >>
ITO electrodes 2 to 9 (ITO flexible) except that the ITO substrate A (ITO flexible transparent substrate A and ITO glass substrate A) is changed to a silver nanowire substrate A (silver nanowire flexible transparent substrate A and silver nanowire glass substrate A). Silver nanowire electrodes 20 to 27 (silver nanowire flexible transparent electrodes 20 to 27 and silver nanowire glass electrodes 20 to 27) were prepared in the same manner as the transparent electrodes 2 to 9 and the ITO glass electrodes 2 to 9).

<Evaluation>
The following evaluation was performed about the produced transparent electrode.
(Conductivity)
For the evaluation of conductivity, the surface resistance was measured using a resistivity meter (Loresta GP (MCP-T610 type): manufactured by Dia Instruments Co., Ltd.). For samples that cannot be measured due to range over, prepare a 3cm x 3cm sample, apply silver paste to the opposite two sides on the conductive polymer-containing layer with a width of about 2mm from the end, and make a source measure unit made by KEITHLEY Using a Model 2400, a DC voltage of 1 V was applied, and 1 v / current value was defined as a sheet resistance value from the current value at that time. Although it depends on the configuration of the auxiliary electrode, it is preferably 1 × 10 ⁷ Ω / □ or less. Evaluation was performed as an index representing conductivity according to the following evaluation criteria.
A: Surface resistance is less than 1 × 10 ⁶ Ω / □: Surface resistance is 1 × 10 ⁶ Ω / □ or more and less than 1 × 10 ⁷ Ω / □ Δ: Surface resistance is 1 × 10 ⁷ Ω / □ or more and less than 1 × 10 ⁸ Ω / □: Surface resistance is 1 × 10 ⁸ Ω / □ or more and less than 1 × 10 ⁹ Ω / □ XX: Surface resistance is 1 × 10 ⁹ Ω / □ or more (transmittance)
As evaluation of the transmittance, the total light transmittance was measured using a HAZE METER NDH5000 manufactured by Tokyo Denshoku Co., Ltd. From the optical loss in the element, it is preferably 80% or more. Evaluation was performed as an index representing transmittance according to the following evaluation criteria.
A: Total light transmittance is 85% or more. O: Total light transmittance is 80% or more and less than 85%. Δ: Total light transmittance is 75% or more and less than 80%. Light transmittance is 70% or more and less than 75% XX: Total light transmittance is 0% or more and less than 70% (cleaning resistance)
Water: isopropyl alcohol = 8: 2 (mass ratio) was added as a washing solvent to the beaker and stirred with a stirrer. A sample of ITO glass electrode or silver nanowire glass electrode was immersed therein for 3 minutes, and further washed with running ultrapure water for 5 minutes. Then, the surface of the transparent conductive layer was visually observed to see if there was any disturbance such as swelling or film peeling, and was evaluated as an index representing washing resistance according to the following evaluation criteria.
○: There is no disorder such as swelling or film peeling on the surface of the transparent conductive layer. X: There is disorder such as swelling or film peeling on the surface of the transparent conductive layer (measurement of nanoindentation elastic modulus).
Using a Triboscope manufactured by Hystron, it was mounted on SPI3800N manufactured by SII Nano Technology and measured. For the measurement, a triangular pyramid diamond indenter called a Belkovic indenter (tip ridge angle 142.3 °) having a tip curvature radius of 75 to 100 nm was used. Apply to the surface at a right angle and apply gradually. After reaching the maximum load, gradually return the load to zero. A value P / A obtained by dividing the maximum load P at this time by the projected area A of the indenter contact portion is calculated as hardness, and this value (hardness = P / A (GPa)) is used as an index representing the nanoindentation elastic modulus. Show.

Note that the projected area A of the indenter contact portion is extrapolated by approximating the initial 30% of the unloading curve to a straight line from the depth-load curve obtained by the indentation test. The contact depth h of the contact portion is obtained as a function of h from the shape of the indenter. As a standard sample, the apparatus was calibrated and measured in advance so that the hardness obtained as a result of pressing fused quartz was 9 GPa.

Details of the principle are described in Handbook of Micro / Nano Tribology (CRC edited by Bharat Bhushan). The measurement was performed with a maximum load of 30 μN. The temperature at the time of measurement was 20 ° C.
(Smoothness)
As evaluation of the smoothness after bending, the surface roughness Ra was measured using an atomic force microscope (AFM) SPI3800N probe station and a SPA400 multifunctional unit (manufactured by Seiko Instruments Inc.).

The cantilever is SI-DF20 (manufactured by Seiko Instruments Inc.), with a resonance frequency of 120 to 150 kHz, a spring constant of 12 to 20 N / m, and a measurement area of 10 μm square measured at a scanning frequency of 1 Hz in a DFM mode (Dynamic Force Mode). did. The smoothness was evaluated based on the following evaluation criteria for the arithmetic average roughness Ra value obtained according to JIS B601 (1994). The transparent electrode is preferably 50 nm or less. As a result of the measurement, Ra was less than 20 nm for all the prepared electrodes before the bending operation.
◎: Ra value after folding is less than 20 nm ○: Ra value after folding is 20 nm or more and less than 50 nm Δ: Ra value after folding is 50 nm or more and less than 100 nm ×: After bending Ra value is 100 nm or more and less than 300 nm. XX: Ra value after bending is 300 nm or more.

(Confirmation of crosslinking)
The IR spectrum of each sample was measured with a Fourier transform infrared spectrometer (FTIR-8300 manufactured by Shimadzu Corporation).

In all the transparent electrodes other than the transparent electrode coated with the coating liquid A, the peak around 3400 cm ⁻¹ derived from the hydroxyl group of the binder decreases, and the binders, the crosslinking agent and the binder, or the binder and the conductive polymer are dehydrated and condensed. As a result, an ether-derived peak appeared at 1140 cm ⁻¹ . On the other hand, no cross-linking was detected in the transparent electrode coated with the coating liquid A. In addition, the increase in the nanoindentation elastic modulus is observed in all the transparent electrodes as compared with the transparent electrode coated with the coating liquid A, and the transparent conductive layer is crosslinked by the addition of the polymer A or a crosslinking agent. I understand.

[Production of organic EL devices]
Using the ITO flexible transparent electrodes 1 to 19 and the silver nanowire flexible transparent electrodes 20 to 27 produced as described above, organic EL devices 1 to 27 were produced according to the following procedure. About the electrode with water-washing tolerance, it used after performing the water-wash process.

For each of the prepared transparent electrodes, a spin coater of Baytron PH510 (manufactured by HC Starck), which is a dispersion of PEDOT / PSS [poly (3,4-ethylenediothiophene) -poly (styrenesulfonate)] = 1: 2.5, was used. Was applied at 1000 rpm for 3 minutes, and a conductive layer having a thickness of 30 nm was formed to convert the transparent electrode into a surface electrode, thereby forming an anode electrode.

Next, each of crucibles for vapor deposition in a commercially available vacuum vapor deposition apparatus was filled with an optimal amount of constituent materials for each layer for manufacturing each element. The evaporation crucible used was made of a resistance heating material made of molybdenum or tungsten.

First, after reducing the vacuum to 1 × 10 ⁻⁴ Pa, the deposition crucible containing α-NPD was energized and heated, and deposited on the anode electrode at a deposition rate of 0.1 nm / second. A hole transport layer was provided.

Next, each light emitting layer was provided by the following procedure.

Ir-1 and Ir-2 and compound 1-1 were co-deposited at a deposition rate of 0.1 nm / second so that the concentration of Ir-1 was 13% by mass and Ir-2 was 3.7% by mass. A green-red phosphorescent light emitting layer having a maximum wavelength of 622 nm and a thickness of 10 nm was formed.

Next, E-1 and Compound 1-1 were co-evaporated at a deposition rate of 0.1 nm / second so that E-1 was 10% by mass, and a blue phosphorescent light emitting layer having an emission maximum wavelength of 471 nm and a thickness of 15 nm was formed. Formed.

Thereafter, M-1 is vapor-deposited to a thickness of 5 nm to form a hole blocking layer, and CsF is co-deposited with M-1 so that the film thickness ratio is 10%, and an electron transport layer having a thickness of 45 nm is formed. Formed.

Further, aluminum was deposited with a thickness of 110 nm to form a cathode.

Next, using a flexible sealing member made of polyethylene terephthalate as a base material and depositing Al ₂ O ₃ with a thickness of 300 nm, the cathode electrode except for the ends so that external lead terminals of the anode electrode and the cathode electrode can be formed. An adhesive was applied around the substrate, a flexible sealing member was bonded, and then the adhesive was cured by heat treatment to produce organic EL devices 1 to 27.

[Evaluation of organic EL devices]
The lifetime of the organic EL devices 1 to 27 was evaluated by the following method.
(lifespan)
Five elements out of 10 elements manufactured by the same manufacturing procedure were continuously emitted at an initial luminance of 5000 cd / m ² , the time until the luminance was halved was determined, and the average value was defined as the lifetime. Further, the operation of bending the remaining 5 elements inward and outward by 45 ° was performed 100 times to obtain the lifetime. The ratio of the lifetime before and after the bending was obtained and evaluated as the lifetime of the organic EL device after the bending according to the following evaluation criteria. It is preferable that it is 70% or more.
A: The ratio of life before and after bending is 85% or more and less than 100%. ○: The ratio of life before and after bending is 70% or more and less than 85%. X: The ratio of life before and after bending. 30% or more and less than 50% XX: The ratio of the life before and after bending is 0% or more and less than 30%. Table 2 shows the results.

In Table 1,
* 1: Mass ratio of conductive polymer / binder * 2: Nanoindentation elastic modulus [GPa]
PH510: PEDOT-PSS CLEVIOS PH510 (solid content 1.89%) (manufactured by HC Starck)
4083: PEDOT-PSS CLEVIOS P AI 4083 (solid content 1.5%) (manufactured by HC Starck)

As is clear from Tables 1 and 2, when the nanoindentation elastic modulus of the transparent conductive layer is 10 Gpa or more from the organic EL devices 3, 4, 19, 21, and 22 in Tables 1 and 2, the surface of the transparent conductive layer becomes fine. It can be seen that cracks occur and the smoothness is impaired. In addition, if there is a protrusion such as an impurity on the auxiliary electrode from the organic EL devices 1, 2, 9, 14, and 27, the elasticity of the conductive polymer layer is low. Therefore, when the electrode is bent, the transparent conductive layer is deformed around the protrusion. However, it can be seen that the organic functional layer was damaged and the lifetime of the organic electronic device was greatly reduced.

From the above, by setting the nanoindentation elastic modulus to 4 GPa or more and 10 GPa or less (configuration of the present invention), the transparent conductive layer can have appropriate stretchability, and even if the transparent electrode is repeatedly bent, the transparent conductive layer It can be seen that the surface is not cracked, and that the bending of the electrode prevents the transparent conductive layer from being deformed together with the protruding portion of the auxiliary electrode, thereby suppressing the deterioration of the function of the organic electronic device.

Claims

In a transparent electrode having a transparent conductive layer comprising a conductive polymer and a binder on a flexible transparent substrate, the binders of the transparent conductive layer have a crosslinked structure, or the binder and the conductive polymer Has a crosslinked structure, the binder is a polymer (A) represented by the following general formula (A), and the nano-indentation elastic modulus of the transparent conductive layer is 4 GPa or more and 10 GPa or less. Transparent electrode.

(In the formula, X 1 to X 3 each independently represents a hydrogen atom or a methyl group, and R 1 to R 3 each independently represents an alkylene group having 5 or less carbon atoms. (Mol%), and 50 ≦ l + m + n ≦ 100.)
2. The transparent electrode according to claim 1, wherein the transparent conductive layer has a nanoindentation elastic modulus of 5.5 GPa to 7.0 GPa.
The transparent electrode according to claim 1, wherein the conductive polymer is a conductive polymer having a π-conjugated conductive polymer component and a polyanion component.
The transparent electrode according to claim 3, wherein the polyanion component is polysulfonic acid.
An organic electronic device using the transparent electrode according to any one of claims 1 to 4.