JP5651910B2 - Transparent conductive film and method for producing transparent conductive film - Google Patents

Description

  The present invention relates to a transparent conductive film having high conductivity, current uniformity and good transparency, and also having excellent migration resistance, and a method for producing the same.

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

Conventionally, as a transparent conductive film, 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 And metal oxide thin films such as tin oxide (FTO, ATO) doped with antimony, conductive nitride thin films such as TiN, ZrN, and HfN, and conductive boride thin films such as LaB ₆ are also known. Various electrodes such as combined Bi ₂ O ₃ / Au / Bi ₂ O ₃ and TiO ₂ / Ag / TiO ₂ are also known. In addition to inorganic substances, transparent conductive films using CNT (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 conductive films because they can achieve both light transmission 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.

  In general, a vapor-phase film forming method such as a vacuum deposition method, a sputtering method, or an ion plating method is used for producing a metal oxide thin film including ITO. However, since these film forming methods require a vacuum environment, the apparatus becomes large and complicated, and a large amount of energy is consumed during film formation. In addition, when ITO or CNT is used, the raw material of the transparent conductive film itself is very expensive.

  Other transparent conductive films include metal fibers such as metal nanowires (see, for example, Patent Document 1), and transparent conductive films in which a fine mesh structure is formed by a metal grid pattern typified by an electromagnetic wave shielding film of a plasma display. (See, for example, Patent Documents 2 and 3). In particular, in a metal mesh using silver, both good conductivity and transparency can be achieved due to the inherent high conductivity of silver.

  However, because of the mesh structure, the portion that transmits light does not have conductivity, and the current cannot be uniform over the entire surface of the transparent conductive film.

In addition, when silver or copper is used for the electrode, a phenomenon called ion migration in which the metal eluted from the electrode precipitates and grows (hereinafter also referred to as migration) is likely to cause a failure such as a short circuit between the electrodes. A problem in durability is known, which is a major obstacle in using a transparent conductive film using silver. Further, a translucent conductive sheet having a conductive surface including a transparent conductive film and a conductive pattern material is known (for example, see Patent Document 4), but migration is not mentioned at all.
US Patent Application Publication No. 2007 / 0074316A1 JP 2000-149773 A JP 2004-221564 A JP 2006-352073 A "Technology of transparent conductive film", page 80 (Ohm Publishing Co.)

  As described above, none of the conventional techniques can solve the problem of obtaining a transparent conductive film satisfying various characteristics. Accordingly, an object of the present invention is to provide a transparent conductive film having high conductivity, current uniformity, good transparency, and excellent migration resistance, and a method for producing the same.

  A transparent conductive film having a mesh-like conductive layer formed of at least one metal on a transparent support, wherein a transparent conductive layer containing a migration inhibitor is disposed on the conductive layer. In the transparent conductive film, it was found that the problems of the present invention can be solved, and the present invention has been achieved. Moreover, by using a transparent resin film for the transparent support, it is possible to obtain a transparent conductive film that satisfies both lightness and flexibility.

  That is, the above object according to the present invention is achieved by the following configuration.

  1. A transparent conductive film having a mesh-like conductive layer formed of at least one metal on a transparent support, wherein a transparent conductive layer containing a migration inhibitor is disposed on the conductive layer. A transparent conductive film.

  2. 2. The transparent conductive film according to 1 above, wherein the at least one metal is silver.

  3. 3. The method for producing a transparent conductive film, wherein the transparent conductive film according to 1 or 2 is produced by a liquid phase film forming method.

  According to the above means of the present invention, it is possible to obtain a transparent conductive film having high conductivity, current uniformity and good transparency as its effects, and also having excellent migration resistance. The transparent conductive film of the present invention can be used in various optoelectronic devices such as flat electrodes such as flat panel displays and solar cells that require high transparency and high conductivity, and electronic paper and touch panels that require lightweight and flexibility. It can be preferably used for a transparent electrode.

  The transparent conductive film of the present invention is a transparent conductive film having a mesh-like conductive layer formed of at least one metal on a transparent support, the transparent conductive layer containing a migration inhibitor on the conductive layer Is installed.

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

(Transparent support)
The transparent support constituting the transparent conductor of the present invention is not particularly limited as long as it has high light transmittance, and its material, shape, structure, thickness, etc. are appropriately selected from known ones. Can do. For example, a glass substrate, a resin substrate, a resin film, etc. are preferably mentioned in terms of excellent hardness as a base material and easy formation of a conductive layer on the surface, but from the viewpoint of lightness and flexibility It is preferable to use a resin film.

  The resin is not particularly limited and can be appropriately selected from known ones. For example, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polyvinyl chloride resin, polyethersulfone resin, polycarbonate resin, Polystyrene resin, polyimide resin, polyetherimide resin, polyvinyl acetate resin, polyvinylidene chloride resin, polyvinylidene fluoride resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, polymethyl methacrylate resin, polyacrylonitrile resin, polyolefin polystyrene Examples thereof include resins, polyamide resins, polybutadiene resins, cellulose acetate, cellulose nitrate, and acrylonitrile-butadiene-styrene copolymer resins. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, polyethylene terephthalate resin is preferable in terms of excellent transparency and flexibility.

[Mesh-like conductive layer]
The transparent conductive film of the present invention has a mesh-like conductive layer formed of at least one metal on a transparent support. The mesh-like conductive layer may be formed using metal fibers such as metal nanowires, or may have a fine mesh structure with a metal grid pattern typified by an electromagnetic wave shielding film of a plasma display.

  In general, a metal nanowire refers to a linear structure having a metal element as a main component and having a diameter from the atomic scale to the nm size. Metal nanowires can be produced by a known technique. However, when metal nanowires are used as a transparent conductive material, the average diameter is preferably smaller than 200 nm in order to reduce the influence of light scattering and increase transparency. In order to increase conductivity, it is preferable that the average diameter is large. In this invention, 10-200 nm is preferable as an average diameter of metal nanowire, and it is more preferable that it is 30-180 nm. The average length is preferably about 3 to 500 μm, more preferably 5 to 300 μm.

  In the present invention, the average diameter and average length of metal nanowires, and the average aspect ratio (average length / average diameter) are obtained by taking an electron micrograph of a sufficient number of metal nanowires and measuring the diameter and length of each metal nanowire. From the measured value, it can be obtained by arithmetic average. Strictly speaking, the length of the metal nanowire should be measured in a linearly stretched state, but in reality it may be curved, so the projected diameter of the nanowire can be measured using an image analyzer from an electron micrograph. Further, the projected area may be calculated and calculated assuming a cylindrical body (length = projected area / projected diameter). The number of measured metal nanowires is preferably at least 100 or more, and more preferably 300 or more.

  As a method of forming a grid pattern with a metal, for example, any method such as a photolithography method, a silver salt method, an ink jet method, or a screen printing method used for forming an electromagnetic wave shielding film of a plasma display can be used. The grid width and interval of the grid pattern are preferably 80% or more as an aperture ratio from the viewpoint of transparency, more preferably 90% or more, and still more preferably 95% or more.

  The mesh-like conductive layer formed of at least one metal in the present invention is characterized in that at least one metal is silver. The metal may be silver alone, an alloy of silver and a metal other than silver, or the silver surface may be plated with a metal other than silver. Plating can be performed by a known method.

[Migration inhibitor]
The transparent conductive film of the present invention is characterized in that a migration inhibitor is contained in the transparent conductive layer placed on the metal mesh conductive layer.

  Silver has the highest conductivity among metals, but on the other hand, it is considered to be the metal that is most likely to cause migration among metals, and the effect of preventing migration is enhanced by the migration inhibitor according to the present invention. be able to.

  For the migration inhibitor according to the present invention, it is preferable to use a compound that binds to a metal ion. As a result, the generated metal ions are captured by the compound that binds to the metal ions, and metal deposition due to migration is prevented. Examples of the compound that binds to the metal ion include benzotriazole, triazine, and isocyanuric adducts thereof.

  The benzotriazole series includes 1H-benzotriazole-1-methanol (chemical formula (2)), which is an adduct of methanol, as well as the basic form of benzotriazole represented by chemical formula (1), and an alkyl group added to the triazole side. And those having an alkyl group added to the benzene side (Chemical Formula (4)).

  The triazine system is represented by the chemical formula (5). For example, 2,4-diamino-6-vinyl-S-triazine represented by the chemical formula (6) or 2,4-diamino compound represented by the chemical formula (7) is used. Examples include diamino-6- [2′-ethyl-4-methylimidazole- (1)]-ethyl-S-triazine and 2,4-diamino-6-methacryloyloxyethyl-S-triazine represented by chemical formula (8). It is done.

  The isocyanuric acid adduct is obtained by adding isocyanuric acid represented by the chemical formula (9) to the above triazine-based or benzotriazole-based compound. An isocyanuric acid adduct of a triazine-based compound is represented by the chemical formula (10). For example, 2,4-diamino-6-vinyl-S-triazine isocyanuric acid represented by the chemical formula (11) or the chemical formula (12) 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid shown.

  Examples of other migration inhibitors include mercapto compounds, thiadiazole compounds, sulfide compounds, and disulfide compounds.

  In addition to these organic compounds, an inorganic ion exchanger may be used as a migration inhibitor. Specifically, oxidation of inorganic oxides such as zirconium oxide, tin oxide, titanium oxide, antimony trioxide, bismuth oxide, lead oxide, magnesium oxide, alumina or composite oxides such as antimony / bismuth, magnesium / alumina. Examples thereof include physical ceramics, various glass powders, and mixtures thereof.

  In order to obtain a good migration suppression effect, the migration inhibitor content in the transparent conductive layer is preferably 0.5% by mass or more and 50% by mass or less, more preferably 2.5% by mass or more and 30% or less. It is below mass%.

  The migration inhibitor according to the present invention may be contained in a layer other than the transparent conductive layer, for example, a support undercoat layer or a metal mesh binder, but the migration of silver ions eluted only in the support undercoat layer. The direction is opposite to the direction, and a sufficient migration prevention effect cannot be obtained. In addition, when a migration inhibitor in an amount necessary for obtaining a migration suppressing effect is localized in the same layer as the metal mesh, the conductivity is lowered due to the migration inhibitor adhering to the surface of the metal mesh. When the necessary amount of migration inhibitor is sufficiently present in the transparent conductive layer placed on the metal mesh conductive layer, silver ions can be effectively captured while maintaining good conductivity.

[Transparent conductive layer]
Examples of the conductive material used for the transparent conductive layer containing the migration inhibitor according to the present invention include conductive polymers. For example, selected from the group consisting of derivatives of polypyrrole, polyaniline, polythiophene, polythienylene vinylene, polyazulene, polyisothianaphthene, polycarbazole, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, polyphenylacetylene, polydiacetylene, and polynaphthalene. Compounds.

  The transparent conductive layer according to the present invention may contain one kind of conductive polymer alone, or may contain two or more kinds of conductive polymers in combination. From the viewpoint, polyaniline having a repeating unit represented by the following general formula (I) or general formula (II), or a derivative thereof, a polypyrrole derivative having a repeating unit represented by the following general formula (III), or the following general formula ( More preferably, it contains at least one compound selected from the group consisting of polythiophene derivatives having a repeating unit represented by IV).

  In the above general formulas (III) and (IV), R is mainly a linear organic substituent, preferably an alkyl group, an alkoxy group, an allyl group, or a combination of these groups. As long as it does not lose its properties, a sulfonate group, an ester group, an amide group, or the like may be bonded to or combined with these. Note that n is an integer.

The conductive polymer used in the transparent conductive layer according to the present invention can be subjected to a doping treatment in order to further increase the conductivity. 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), a halogen atom. Lewis acid, proton acid, transition metal halide, transition metal compound, alkali metal, alkaline earth metal, MClO ₄ (M = Li ⁺ , Na ⁺ ), R ₄ N ⁺ (R = CH ₃ , C ₄ H ₉ , C ₆ H ₅ ), or R ₄ P ⁺ (R═CH ₃ , C ₄ H ₉ , C ₆ H ₅ ). Of these, the long-chain sulfonic acid is preferable.

Examples of the long chain sulfonic acid include dinonyl naphthalene disulfonic acid, dinonyl naphthalene sulfonic acid, and dodecylbenzene sulfonic acid. Examples of the halogen include Cl ₂ , Br ₂ , I ₂ , ICl ₃ , IBr, and IF ₅ . Examples of the Lewis acid include PF ₅ , AsF ₅ , SbF ₅ , BF ₃ , BCl ₃ , BBr ₃ , SO ₃ , and GaCl ₃ . 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. In the transparent conductive film of the present invention, the dopant is preferably contained in an amount of 0.001 part by mass or more with respect to 100 parts by mass of the conductive polymer. Furthermore, it is more preferable that 0.5 mass part or more is contained.

The transparent conductive layer according to the present invention includes a long-chain sulfonic acid, a polymer of a long-chain sulfonic acid (for example, polystyrene sulfonic acid), a halogen, a Lewis acid, a proton acid, a transition metal halide, a transition metal compound, and an alkali metal. And at least one dopant selected from the group consisting of alkaline earth metals, MClO ₄ , R ₄ N ⁺ , and R ₄ P ⁺ and fullerenes.

  The conductive polymer used in the transparent conductive layer according to the present invention was modified by a metal disclosed in JP-T-2001-511581, JP-A-2004-99640, JP-A-2007-165199, or the like. A conductive polymer can also be used.

  The transparent conductive layer containing the conductive polymer according to the present invention may contain a water-soluble organic compound. Among water-soluble organic compounds, compounds having an effect of improving conductivity by adding to a conductive polymer material are known, and 2nd. Sometimes called a dopant (or sensitizer).

  2nd. Which can be used in the transparent conductive layer according to the present invention. There is no restriction | limiting in particular in a dopant, 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, and glycerin. 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 transparent conductive layer containing the conductive polymer according to the present invention, the 2nd. 0.001 mass part or more is preferable, as for content of a dopant, 0.01-50 mass parts is more preferable, and 0.01-10 mass parts is especially preferable.

  The transparent conductive layer may use metal oxides such as indium tin oxide (ITO), tin oxide, antimony-doped tin oxide, zinc-doped tin oxide, and zinc oxide as the transparent conductive material.

  The transparent conductive layer according to the present invention may contain a transparent resin component or additive in addition to the conductive polymer in order to ensure film formability and film strength. The transparent resin component is not particularly limited as long as it is compatible with or mixed with the conductive polymer, and may be a thermosetting resin or a thermoplastic resin.

  For example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyimide resins such as polyimide and polyamideimide, polyamide resins such as polyamide 6, polyamide 6,6, polyamide 12 and polyamide 11, polyvinylidene fluoride, Fluorine resin such as polyvinyl fluoride, polytetrafluoroethylene, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, etc., vinyl resin such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, polyvinyl chloride, epoxy resin, xylene Resin, aramid resin, polyurethane resin, polyurea resin, melamine resin, phenol resin, polyether, acrylic resin and this And La copolymers thereof.

  Various functional layers such as a hard coat layer, a non-glare coat layer, a barrier coat layer, an anchor coat layer, a carrier transport layer, and a carrier accumulation layer can be added to the transparent conductive layer according to the present invention as necessary. When providing a hard coat layer or a non-glare coat layer, it is preferable to place the transparent support on the opposite side of the transparent conductive layer according to the present invention, and when providing a barrier coat layer, a transparent support. And the transparent conductive layer according to the present invention is preferably disposed between the transparent conductive layer according to the present invention, and when an anchor coat layer, a carrier transport layer, or a carrier accumulation layer is provided, the transparent support is the same as the transparent conductive layer according to the present invention. It is preferable to arrange on the side.

  There is no restriction | limiting in particular in the thickness of the transparent conductive layer which concerns on this invention, According to the objective, it can select suitably. In order to increase the smoothness of the conductive surface, the thickness of the transparent conductive layer may be thicker than the thickness of the metal mesh, or the transparent conductive layer may be installed after the light transmitting portion of the metal mesh is flattened with a resin or the like. However, since the transparency improves as the thickness decreases, it is generally preferably 10 μm or less.

  The total light transmittance in the transparent conductive layer according to the present invention is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. The total light transmittance can be measured according to a known method using a spectrophotometer or the like.

[Transparent conductive film]
The electrical resistance value in the transparent conductive film of the present invention is preferably 10 ³ Ω / □ or less as the surface resistivity, more preferably 10 ² Ω / □ or less, and more preferably 10 Ω / □ or less. Particularly preferred. If it exceeds 10 ³ Ω / □, when used as a transparent electrode such as a liquid crystal display or a transparent touch panel or as an electromagnetic shielding material, it may not function sufficiently as an electrode, or sufficient electromagnetic shielding characteristics may not be obtained. The surface resistivity can be measured based on, for example, JIS K7194, ASTM D257, etc., or can be easily measured using a commercially available surface resistivity meter.

[Method for producing transparent conductive film]
The method for producing the transparent conductive film of the present invention is not particularly limited, but it is applied to the formation of the transparent conductive layer from the viewpoint of productivity and production cost, electrode quality such as smoothness and uniformity, and environmental load reduction. It is preferable to use a liquid phase film forming method such as a printing method or a printing method.

  As coating methods, roll coating method, bar coating method, dip coating method, spin coating method, casting method, die coating method, blade coating method, bar coating method, gravure coating method, curtain coating method, spray coating method, doctor coating method Etc. can be used. As the printing method, a letterpress (letter) printing method, a stencil (screen) printing method, a lithographic (offset) printing method, an intaglio (gravure) printing method, a spray printing method, an ink jet printing method, and the like can be used. In addition, as needed, physical surface treatments, such as a corona discharge treatment and a plasma discharge treatment, can also be performed on the transparent support surface as a preliminary treatment for improving adhesion and coating properties.

  The transparent conductive film of the present invention includes various types of optoelectronic devices such as liquid crystal, plasma, organic electroluminescence, field emission, various types of displays, touch panels, mobile phones, electronic paper, various solar cells, various electroluminescent dimming elements, etc. Can be preferably used for transparent electrodes, transparent circuits, and transparent wiring.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
<< Preparation of transparent conductive film >>
[Preparation of transparent conductive film TC-1]
With reference to the method described in Non-Patent Document 4 (Adv. Mater. 2002, 14, 833 to 837), silver nanowires were produced by the following method.

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

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

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

  Using the produced silver nanowire dispersion liquid, a metal mesh-like transparent conductive film TC-1 was produced according to the following method.

A dispersion of silver nanowires was applied on a polyethylene terephthalate (PET) support having a total light transmittance of 90% so that the amount of silver nanowires was 0.3 g / m ² and dried using a spin coater. Subsequently, the silver nanowire coating layer was calendered, and then a methyl isobutyl ketone solution of urethane acrylate was applied using a spin coater and dried to prepare a transparent conductive film TC-1.

  The thickness of the urethane acrylate layer was set such that the silver nanowire layer was not completely buried, a part of the urethane acrylate layer was exposed from the urethane acrylate layer, and the silver nanowire layer could be fixed to the support.

[Preparation of transparent conductive film TC-2]
A metal mesh-like transparent conductive film TC-2 with a grid pattern was produced by the silver salt method shown below.

(Preparation of silver halide emulsion)
The following solution A was kept at 34 ° C. in a reaction vessel, and the pH was adjusted to 2.95 using nitric acid (concentration 6%) while stirring at high speed using a mixing and stirring device described in JP-A-62-2160128. It was adjusted. Subsequently, the following solution B and the following solution C were added at a constant flow rate over 8 minutes and 6 seconds using the double jet method. After completion of the addition, the pH was adjusted to 5.90 using sodium carbonate (concentration 5%), and then the following solution D and solution E were added.

(Solution A)
Alkali-treated inert gelatin (average molecular weight 100,000) 18.7g
Sodium chloride 0.31g
Solution I (below) 1.59ml
Pure water 1246ml
(Solution B)
169.9g of silver nitrate
Nitric acid (concentration 6%) 5.89ml
Finish to 317.1 ml with pure water (Solution C)
Alkali-treated inert gelatin (average molecular weight 100,000) 5.66 g
Sodium chloride 58.8g
13.3 g of potassium bromide
Solution I (below) 0.85ml
Solution II (below) 2.72 ml
Finish to 317.1 ml with pure water (Solution D)
2-Methyl-4hydroxy-1,3,3a, 7-tetraazaindene 0.56 g
112.1 ml of pure water
(Solution E)
Alkali-treated inert gelatin (average molecular weight 100,000) 3.96 g
Solution I (below) 0.40ml
128.5 ml of pure water
(Solution I)
Surfactant: 10% by weight methanol solution of polyisopropylene polyethylene oxydisuccinate sodium salt (Solution II)
10 mass% aqueous solution of rhodium hexachloride complex.

  After completion of the above operation, desalting and washing with water using a flocculation method are performed at 40 ° C. according to a conventional method, and the solution F and an anti-bacterial agent are added and dispersed well at 60 ° C. To 90.90 to obtain a silver chlorobromide cubic grain emulsion finally containing 10 mol% of silver bromide and having an average grain size of 0.09 μm and a coefficient of variation of 10%.

(Solution F)
Alkali-treated inert gelatin (average molecular weight 100,000) 16.5g
Pure water 139.8ml
The silver chlorobromide cubic grain emulsion was subjected to chemical sensitization at 40 ° C. for 80 minutes using 20 mg of sodium thiosulfate per mole of silver halide, and after completion of chemical sensitization, 4-hydroxy-6-methyl- 1,3,3a, 7-tetrazaindene (TAI) was added in an amount of 500 mg per mole of silver halide and 1-phenyl-5-mercaptotetrazole was added in an amount of 150 mg per mole of silver halide to obtain a silver halide emulsion. . This silver halide emulsion had a volume ratio of silver halide grains to gelatin (silver halide grains / gelatin) of 0.625.

  Further, a hardening agent (H-1: tetrakis (vinylsulfonylmethyl) methane) was added at a ratio of 200 mg per 1 g of gelatin, and a surfactant (SU-2: sulfosuccinate disulfate) was applied as a coating aid. (2-ethylhexyl) .sodium) was added to adjust the surface tension.

The coating solution thus obtained was applied onto a 100 μm thick polyethylene terephthalate film support with an undercoat layer so that the amount of silver applied was 0.625 g / m ^2, and then cured at 50 ° C. for 24 hours. Processing was carried out to obtain a photosensitive material.

〔exposure〕
The obtained photosensitive material was exposed with a UV exposure device through a mesh photomask (pitch / line width = 300 μm / 5 μm).

[Chemical development]
The exposed photosensitive material is developed for 60 seconds at 25 ° C. using the following developer (DEV-1), and then fixed for 120 seconds at 25 ° C. using the following fixing solution (FIX-1). It was.

(DEV-1)
500 ml of pure water
Metol 2g
80 g of anhydrous sodium sulfite
Hydroquinone 4g
4g borax
Sodium thiosulfate 10g
Potassium bromide 0.5g
Add water to bring the total volume to 1 liter (FIX-1)
750 ml of pure water
Sodium thiosulfate 250g
Anhydrous sodium sulfite 15g
Glacial acetic acid 15ml
Potash alum 15g
Add water to bring the total volume to 1 liter [Physical development]
Next, physical development was performed at 30 ° C. for 10 minutes using the following physical developer (PDEV-1), followed by washing with water and drying.

(PDEV-1)
900ml pure water
Citric acid 10g
Trisodium citrate 1g
Ammonia water (28%) 1.5g
Hydroquinone 2.3g
Silver nitrate 0.23g
Add water to bring the total volume to 1000 ml.

[Washing and drying]
The washing process was performed with tap water for 10 minutes. Moreover, the drying process was dried until it became a dry state using drying air (50 degreeC), and the metal mesh-like transparent conductive film TC-2 in which the silver grid pattern was formed was obtained.

[Preparation of Transparent Conductive Films TC-3, 4]
Using a dispersion of conductive polyaniline containing a sulfonic acid dopant as a transparent conductive layer ORMECON D1033 (manufactured by Olmecon, Germany) on the metal mesh conductive layers of the transparent conductive films TC-1 and TC-2. Transparent conductive films TC-3 and 4 were prepared in the same manner as the transparent conductive films TC-1 and TC-2, except that the dry film thickness was 0.2 μm.

[Preparation of transparent conductive film TC-5]
In transparent conductive film TC-3, except that 2.5 mass% of 2,4-diamino-6-vinyl-S-triazine / isocyanuric acid adduct is included in the urethane acrylate layer, the same as transparent conductive film TC-3 A transparent conductive film TC-3 was produced.

[Preparation of Transparent Conductive Films TC-6, 7]
Transparent conductive film TC-3, 4 except that transparent conductive layer TC-3, 4 contains 2.5 mass% of 2,4-diamino-6-vinyl-S-triazine-isocyanuric acid adduct in the transparent conductive layer. In the same manner, transparent conductive films TC-6 and 7 were produced.

[Preparation of transparent conductive film TC-8]
In the transparent conductive film TC-3, 0.5% by mass of 2,4-diamino-6-vinyl-S-triazine isocyanuric acid adduct in the urethane acrylate layer and 2,4-diamino-6 in the transparent conductive layer A transparent conductive film TC-8 was produced in the same manner as the transparent conductive film TC-3 except that 2.0% by mass of a vinyl-S-triazine / isocyanuric acid adduct was contained.

<< Evaluation of transparent conductive film >>
[Surface specific resistance, transmittance]
The surface resistivity and transmittance of the transparent conductive films TC-1 to TC-8 were measured by the following methods.

(Surface resistivity)
The surface specific resistance was measured by a four-point method using a resistivity meter Loresta GP manufactured by Dia Instruments.

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

[Current uniformity]
Using the transparent conductive films TC-1 to TC-8, the black and white display elements ED-1 to ED-8 were manufactured as follows, and the current uniformity was evaluated.

<Production of black and white display element>
(Preparation of electrolyte solution)
After 20 mg of p-toluenesulfonate and 45 mg of 3-mercapto-1,2,4-triazole were added and completely dissolved in 2.5 g of propylene carbonate, 0.5 g of titanium oxide was added and ultrasonically dispersed. The titanium oxide was dispersed with a machine. To this solution, 100 mg of polyethylene glycol (average molecular weight 500,000) was added and stirred for 1 hour while heating at 120 ° C. to obtain an electrolyte solution.

(Preparation of silver electrode)
A Cu film was formed on the entire surface by a known sputtering method on a 2 cm × 4 cm glass substrate having a thickness of 1.5 mm, and then 10 μm of silver was deposited on the Cu electrode by electrolytic plating to produce a silver electrode.

(Production of black and white display elements)
The prepared electrolyte solution is applied onto the transparent conductive films TC-1 to TC-8 cut to a size of 2 cm × 4 cm, and the silver electrodes are sandwiched in a perpendicular direction from above and pressed at a pressure of 9.8 kPa. And the peripheral part was sealed and the monochrome display elements ED-1-8 were produced. The overlapped portion of 2 cm × 2 cm is a display portion, and the remaining portion is used as a lead portion.

  About the produced black and white display element, the positive electrode side of the alkaline single battery is connected to the transparent conductive film, the negative electrode side is connected to the silver electrode, and a DC voltage of 1.5 V is applied between both electrodes, so that the display portion is white to black The state of the change was visually observed from the transparent conductive film side, and the current uniformity was subjected to sensory evaluation according to the following criteria.

○: The entire display surface is dark black with no unevenness △: The entire display surface is black, but the density is slightly light and slightly uneven ×: The metal mesh portion is blackened so that only the metal mesh portion is blurred Other than that, the white color remains uneven, and evaluations positioned in the middle of the respective ranks are displayed as, for example, Δ to ○ and × to Δ.

(Migration resistance)
Using the transparent conductive films TC-1 to TC-8, the migration resistance was evaluated by a forced deterioration test as follows.

  Agar gel with a film thickness of 500 μm is applied on a transparent conductive film cut out to a size of 2 cm × 4 cm, and the same silver electrode as that prepared for a display element is further bonded to the transparent film in a perpendicular direction. An evaluation sample was prepared.

  Regarding the metal mesh of the transparent conductive film, the positive electrode side of the DC power supply is connected to the transparent conductive film, the negative electrode side is connected to the silver electrode, and a DC voltage of 50 V is applied between both electrodes under the conditions of 23 ° C. and 93% RH. The change with time was observed and evaluated with an electron microscope. The sensory evaluation of the results obtained by observation with the electron microscope was performed, and migration resistance was evaluated according to the following criteria.

○: No change in the metal mesh is observed Δ: Dissolution or precipitation of the metal mesh due to migration is slightly recognized, but is in an allowable range for practical use ×: Dissolution of the metal mesh due to migration or dendritic precipitation is observed Obviously, the metal mesh and the silver electrode are short-circuited. Evaluations located in the middle of the respective ranks are indicated by, for example, Δ to ○ and × to Δ.

  Table 1 shows the evaluation results of the transparent conductive film obtained as described above.

  As is clear from the results shown in Table 1, the transparent conductors TC-6 to 8 of the present invention have high conductivity and good transparency with respect to the comparative transparent conductors TC-1 to TC-5. It can also be seen that it has current uniformity and excellent migration resistance.

Claims (4)

A transparent conductive film having a mesh-like conductive layer formed of at least one metal on a transparent support, wherein a migration inhibitor (however, 2,4-dichloro-6-hydroxy-s is formed on the conductive layer) -A transparent conductive layer containing triazine sodium salt) is installed ,
The migration inhibitor is a benzotriazole compound, a triazine compound, or an isocyanuric adduct thereof.
The transparent conductive layer is characterized by not containing ITO . The conductive material used for the transparent conductive layer is a conductive polymer containing polyaniline having a repeating unit represented by the following general formula (I) or general formula (II), or a derivative thereof, but does not include carbon nanotubes. The transparent conductive film according to claim 1.
  The transparent conductive film according to claim 1, wherein the at least one metal is silver.   The transparent conductive film of any one of Claims 1-3 is manufactured with a liquid phase film-forming method, The manufacturing method of the transparent conductive film characterized by the above-mentioned.