JP7168691B2 - Conductive substrate manufacturing method, conductive substrate - Google Patents

Description

The present invention relates to a method for manufacturing a conductive substrate and a conductive substrate.

BACKGROUND ART Conductive substrates having conductive thin wires (thin wire-like wiring showing conductivity) are widely used in various applications such as touch panels, solar cells, and EL (electroluminescence) elements. In particular, in recent years, the mounting rate of touch panels on mobile phones and mobile game devices has been increasing, and the demand for conductive substrates for capacitive touch panels capable of multi-point detection is rapidly expanding.
As a method for producing a conductive substrate, in Patent Document 1, a photosensitive layer containing silver halide is subjected to exposure treatment, development treatment, and the like in sequence to form a conductive thin line containing metallic silver. disclosed.

JP 2007-129205 A

On the other hand, in recent years, there has been a demand for further thinning of conductive thin wires.
The present inventor attempted to form a conductive thin line with a further reduced width (for example, a width of 2.0 μm or less) according to the method disclosed in Patent Document 1, and found that the obtained conductive thin line had a conductivity of was found to be insufficient.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a conductive substrate having thin conductive wires with excellent conductivity.
Another object of the present invention is to provide a conductive substrate having fine conductive wires with excellent conductivity.

As a result of intensive studies on the above problem, the inventors have found that the above problem can be solved by the following configuration.

(1) Step A of forming a silver halide-containing photosensitive layer containing silver halide, gelatin, and a polymer different from gelatin on a support;
A step of exposing and developing the silver halide-containing photosensitive layer to form a fine linear silver-containing layer containing metallic silver, gelatin, and a polymer different from gelatin and having a width of 2.0 μm or less. B and
a step C of subjecting the silver-containing layer obtained in step B to a heat treatment;
a step D of removing the gelatin in the silver-containing layer obtained in step C;
a step E of plating the silver-containing layer obtained in step D to form a conductive thin wire;
has
A method for producing a conductive substrate, wherein the width of the region where the metal exists is 2.0 μm or less in the vertical cross section of the conductive fine wire in the direction orthogonal to the direction in which the conductive fine wire extends.
(2) The method for producing a conductive substrate according to (1), wherein the silver halide is particles having an equivalent spherical diameter of 10 to 200 nm.
(3) The method for producing a conductive substrate according to (1) or (2), wherein the plating treatment is silver plating treatment or copper plating treatment.
(4) The method for producing a conductive substrate according to (3), wherein the plating treatment is silver plating treatment.
(5) The support has on its surface a silver halide-free layer containing gelatin and a polymer different from gelatin and having a thickness of more than 1.0 μm. ) to (4), the method for producing a conductive substrate.
(6) The method for producing a conductive substrate according to any one of (1) to (5), wherein step C is a step of bringing the silver-containing layer obtained in step B into contact with superheated steam.
(7) The method for producing a conductive substrate according to any one of (1) to (6), further comprising a step F of smoothing the conductive thin wires obtained in step E.
(8) The method for producing a conductive substrate according to (7), further comprising a step G of heat-treating the conductive thin wire obtained in step F after step F.
(9) a support;
a conductive wire containing a polymer and a metal disposed on a support;
In a vertical cross section of the conductive thin wire in a direction orthogonal to the direction in which the conductive thin wire extends, the width of the region where the metal exists is 2.0 μm or less,
An electrically conductive substrate wherein, in a vertical cross-section, the height to width ratio of the areas in which the metal is present is greater than 0.40.
(10) The conductive substrate according to (9), wherein the mesh pattern is formed by conductive fine lines.
(11) The conductive substrate according to (10), wherein the mesh pattern has an aperture ratio of 95.00% or more.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrically conductive substrate which has the electrically conductive thin line|wire which was excellent in electrical conductivity can be provided.
Moreover, according to the present invention, it is possible to provide a conductive substrate having fine conductive wires with excellent conductivity.

FIG. 2 is a cross-sectional view of one embodiment of a conductive substrate; 1 is a vertical cross-sectional view of a conductive thin wire; FIG. FIG. 4 is a plan view showing one embodiment of a mesh pattern formed by conductive fine lines;

The present invention will be described in detail below.
Although the description of the constituent elements described below may be made based on representative embodiments of the present invention, the present invention is not limited to such embodiments.
In this specification, a numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits.

A feature of the present invention compared with the prior art is that a plating process is performed when thinned conductive thin wires are obtained.
In the conventional method of producing a conductive substrate using silver halide, the amount of metal in the resulting conductive fine wire decreases as the conductive fine wire becomes thinner, and sufficient conductivity is not ensured. Therefore, the present inventors removed gelatin from the silver-containing layer to be described later, and then performed a plating treatment to fill the space from which the gelatin was removed with a metal (plated metal). By increasing the amount of metal in the conductive thin wire, a conductive thin wire exhibiting excellent conductivity is formed. In other words, the inventors of the present invention have found for the first time the problem that occurs in thinning in the conventional method, and have provided a method for solving the problem.

The method for manufacturing a conductive substrate according to the present invention has steps A to E, which will be described later, in this order.
Each step will be described in detail below.

<Process A>
In step A, a silver halide-containing photosensitive layer (hereinafter referred to as "photosensitive layer ) is formed. Through this step, a support with a photosensitive layer to which the exposure treatment described below is applied is produced.
First, the materials and members used in step A are described in detail, and then the procedure of step A is described in detail.

(support)
The type of the support is not particularly limited as long as it can support the photosensitive layer, and examples thereof include plastic substrates, glass substrates, and metal substrates, with plastic substrates being preferred.
The thickness of the support is not particularly limited, and is often 25 to 500 μm. When the conductive substrate is applied to a touch panel and the surface of the support is used as a touch surface, the thickness of the support may exceed 500 μm.

Materials constituting the support include polyethylene terephthalate (PET) (258°C), polycycloolefin (134°C), polycarbonate (250°C), acrylic film (128°C), polyethylene naphthalate (269°C), polyethylene ( 135°C), polypropylene (163°C), polystyrene (230°C), polyvinyl chloride (180°C), polyvinylidene chloride (212°C), and triacetyl cellulose (290°C) with a melting point below about 290°C. Certain resins are preferred, with PET, polycycloolefins, and polycarbonates being more preferred.
The total light transmittance of the support is preferably 85-100%.

A subbing layer may be disposed on the surface of the support.
The undercoat layer preferably contains a specific polymer, which will be described later. The use of this undercoat layer further improves the adhesion of the conductive fine wires to the support, which will be described later.
The method for forming the undercoat layer is not particularly limited, and examples thereof include a method in which a composition for forming an undercoat layer containing a specific polymer is applied onto a support and, if necessary, heat treatment is performed. The undercoat layer-forming composition may contain a solvent, if necessary. The type of solvent is not particularly limited, and examples thereof include solvents used in the composition for forming a photosensitive layer, which will be described later. Moreover, you may use the latex containing the particle|grains of a specific polymer as a composition for undercoat formation containing a specific polymer.
The thickness of the undercoat layer is not particularly limited, and is preferably 0.02 to 0.3 μm, more preferably 0.03 to 0.2 μm, from the viewpoint of better adhesion of the conductive layer to the support.

(silver halide)
The halogen atoms contained in the silver halide may be chlorine, bromine, iodine or fluorine atoms, or may be a combination thereof. For example, a silver halide mainly composed of silver chloride, silver bromide, or silver iodide is preferable, and a silver halide mainly composed of silver chloride or silver bromide is more preferable. Silver chlorobromide, silver iodochlorobromide, or silver iodobromide is also preferably used.
Here, for example, "silver halide composed mainly of silver chloride" refers to silver halide in which the mole fraction of chloride ions in all halide ions is 50% or more in the silver halide composition. The silver halide composed mainly of silver chloride may contain bromide ions and/or iodide ions in addition to chloride ions.

Silver halide is usually in the form of solid particles, and the average particle diameter of the silver halide is preferably 10 to 1000 nm, more preferably 10 to 200 nm, in terms of diameter equivalent to a sphere. 50 to 150 nm is more preferable because the change is smaller.
The equivalent sphere diameter is the diameter of a spherical particle having the same volume.
The "equivalent sphere diameter" used as the average grain size of the silver halide is an average value obtained by measuring the equivalent sphere diameters of 100 silver halide grains and averaging them arithmetically.

The shape of the silver halide grains is not particularly limited, and examples include spherical, cubic, tabular (hexagonal tabular, triangular tabular, quadrangular tabular, etc.), octahedral, and tetradecahedral forms. shape.

(gelatin)
The type of gelatin is not particularly limited, and examples thereof include lime-processed gelatin and acid-processed gelatin. Hydrolysates of gelatin, enzymatic hydrolysates of gelatin, and gelatins modified with amino groups and/or carboxyl groups (phthalated gelatin and acetylated gelatin) may also be used.

(polymer different from gelatin)
The photosensitive layer contains a polymer other than gelatin. By including this specific polymer in the photosensitive layer, the strength of the conductive thin line formed from the photosensitive layer is further improved.
The type of the specific polymer is not particularly limited as long as it is different from gelatin, and a polymer that decomposes gelatin and is not decomposed by a proteolytic enzyme or an oxidizing agent, which will be described later, is preferable.
Specific polymers include hydrophobic polymers (water-insoluble polymers), for example, (meth)acrylic resins, styrene resins, vinyl resins, polyolefin resins, polyester resins, polyurethane resins, At least one resin selected from the group consisting of polyamide-based resins, polycarbonate-based resins, polydiene-based resins, epoxy-based resins, silicone-based resins, cellulose-based polymers, and chitosan-based polymers, or constitutes these resins and copolymers composed of monomers that
Moreover, the specific polymer preferably has a reactive group that reacts with a cross-linking agent, which will be described later.
The specific polymer is preferably particulate. In other words, the photosensitive layer preferably contains particles of the specific polymer.

As the specific polymer, a polymer (copolymer) represented by the following general formula (1) is preferable.
General formula (1): -(A)x-(B)y-(C)z-(D)w-
In general formula (1), A, B, C and D each represent a repeating unit represented by the following general formulas (A) to (D).

R ¹ represents a methyl group or a halogen atom, preferably a methyl group, a chlorine atom or a bromine atom. p represents an integer of 0 to 2, preferably 0 or 1, more preferably 0;
R ² represents a methyl group or an ethyl group, preferably a methyl group.
R ³ represents a hydrogen atom or a methyl group, preferably a hydrogen atom. In general formula (C), L represents a divalent linking group, preferably a group represented by general formula (F) below.
General formula (F): -(CO-X ¹ )r-X ² -
In general formula (F), X ¹ represents an oxygen atom or -NR ³⁰ -. Here, R ³⁰ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group, each of which may have a substituent (for example, a halogen atom, a nitro group, and a hydroxyl group). R ³⁰ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (eg, methyl group, ethyl group, n-butyl group, n-octyl group), or an acyl group (eg, acetyl group, and benzoyl group) is preferred. X ¹ is preferably an oxygen atom or -NH-.
X ² represents an alkylene group, an arylene group, an alkylenearylene group, an arylenealkylene group, or an alkylenearylenealkylene group, and these groups include -O-, -S-, -CO-, -COO-, -NH -, -SO ₂ -, -N(R ³¹ )-, or -N(R ³¹ )SO ₂ - may be inserted in the middle. R ³¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms. X ² is a dimethylene group, trimethylene group, tetramethylene group, o-phenylene group, m-phenylene group, p-phenylene group, -CH ₂ CH ₂ OCOCH ₂ CH ₂ -, or -CH ₂ CH ₂ OCO ( C ₆ H ₄ )— is preferred.
r represents 0 or 1;
q represents 0 or 1, with 0 being preferred.

R ⁴ represents an alkyl group, an alkenyl group, or an alkynyl group, preferably an alkyl group having 5 to 50 carbon atoms, more preferably an alkyl group having 5 to 30 carbon atoms, and further an alkyl group having 5 to 20 carbon atoms. preferable.
R ⁵ represents a hydrogen atom, a methyl group, an ethyl group, a halogen atom, or —CH ₂ COOR ⁶ , preferably a hydrogen atom, a methyl group, a halogen atom, or —CH ₂ COOR ⁶ , a hydrogen atom, a methyl group; , or -CH ₂ COOR ⁶ is more preferred, and a hydrogen atom is even more preferred.
R ⁶ represents a hydrogen atom or an alkyl group having 1 to 80 carbon atoms and may be the same as or different from R ⁴ . R ⁶ preferably has 1 to 70 carbon atoms, more preferably 1 to 60 carbon atoms.

In general formula (1), x, y, z, and w represent the molar ratio of each repeating unit.
x is 3 to 60 mol %, preferably 3 to 50 mol %, more preferably 3 to 40 mol %.
y is 30 to 96 mol%, preferably 35 to 95 mol%, more preferably 40 to 90 mol%.
z is 0.5 to 25 mol %, preferably 0.5 to 20 mol %, more preferably 1 to 20 mol %.
w is 0.5 to 40 mol %, preferably 0.5 to 30 mol %.
In general formula (1), x is preferably 3 to 40 mol%, y is 40 to 90 mol%, z is 0.5 to 20 mol%, and w is 0.5 to 10 mol%.

A polymer represented by the following general formula (2) is preferable as the polymer represented by the general formula (1).

In general formula (2), x, y, z and w are as defined above.

The polymer represented by formula (1) may contain repeating units other than the repeating units represented by formulas (A) to (D).
Examples of monomers for forming other repeating units include acrylic acid esters, methacrylic acid esters, vinyl esters, olefins, crotonic acid esters, itaconic acid diesters, maleic acid diesters, and fumaric acid diesters. , acrylamides, unsaturated carboxylic acids, allyl compounds, vinyl ethers, vinyl ketones, vinyl heterocyclic compounds, glycidyl esters, and unsaturated nitriles. These monomers are also described in paragraphs 0010 to 0022 of Japanese Patent No. 3754745. From the viewpoint of hydrophobicity, acrylic acid esters or methacrylic acid esters are preferred, and hydroxyalkyl methacrylates or hydroxyalkyl acrylates are more preferred.
The polymer represented by general formula (1) preferably contains a repeating unit represented by general formula (E).

In the above formula, L _E represents an alkylene group, preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 2 to 6 carbon atoms, and even more preferably an alkylene group having 2 to 4 carbon atoms.

A polymer represented by the following general formula (3) is particularly preferable as the polymer represented by the general formula (1).

In the above formula, a1, b1, c1, d1, and e1 represent the molar ratio of each repeating unit, a1 is 3 to 60 (mol%), b1 is 30 to 95 (mol%), c1 is 0.5 to 25 (mol %), d1 represents 0.5 to 40 (mol %), and e1 represents 1 to 10 (mol %).
The preferred range of a1 is the same as the preferred range of x above, the preferred range of b1 is the same as the preferred range of y above, the preferred range of c1 is the same as the preferred range of z above, and the preferred range of d1 is It is the same as the preferred range of w above.
e1 is 1 to 10 mol %, preferably 2 to 9 mol %, more preferably 2 to 8 mol %.

The specific polymer can be synthesized with reference to, for example, Japanese Patent No. 3305459 and Japanese Patent No. 3754745.
The weight average molecular weight of the specific polymer is not particularly limited, and is preferably 1,000 to 1,000,000, more preferably 2,000 to 750,000, and even more preferably 3,000 to 500,000.

The photosensitive layer may contain materials other than those mentioned above, if necessary.
Examples thereof include metal compounds belonging to Groups 8 and 9 such as rhodium compounds and iridium compounds used for stabilizing silver halide and increasing sensitivity. Alternatively, antistatic agents, nucleation accelerators, spectral sensitizing dyes, surfactants, antifoggants, hardeners, black spot prevention, as described in paragraphs 0220 to 0241 of JP-A-2009-004348. Also included are agents, redox compounds, monomethine compounds, and dihydroxybenzenes. Furthermore, the photosensitive layer may contain physical development nuclei.

In addition, the photosensitive layer may contain a cross-linking agent used for cross-linking the specific polymers. The inclusion of the cross-linking agent promotes cross-linking between the specific polymers, so that even when the gelatin is decomposed and removed, the connection between the metallic silver particles in the conductive layer is maintained.

(Procedure of process A)
The method of forming a photosensitive layer containing the above components in step A is not particularly limited, but from the viewpoint of productivity, a composition for forming a photosensitive layer containing silver halide, gelatin and a specific polymer is coated on a support. A method of contacting to form a photosensitive layer on a support is preferred.
The form of the composition for forming a photosensitive layer used in this method will be described in detail below, and then the procedure of the steps will be described in detail.

(Material contained in composition for forming photosensitive layer)
The photosensitive layer-forming composition contains the above-described silver halide, gelatin, and specific polymer. In addition, the specific polymer may be contained in the composition for forming a photosensitive layer in the form of particles, if necessary.
The composition for forming a photosensitive layer may contain a solvent, if necessary.
Solvents include water, organic solvents (eg, alcohols, ketones, amides, sulfoxides, esters, and ethers), ionic liquids, and mixed solvents thereof.

The method of contacting the composition for forming a photosensitive layer with the support is not particularly limited. A method of immersing the support and the like can be mentioned.
In addition, after the above treatment, a drying treatment may be performed as necessary.

(Silver halide-containing photosensitive layer)
The photosensitive layer formed by the above procedure contains silver halide, gelatin and a specific polymer.
The content of silver halide in the photosensitive layer is not particularly limited, and is preferably 3.0 to 20.0 g/m ² , more preferably 5.0 to 15 g/m 2 in terms of silver, from the viewpoint of better conductivity of the conductive substrate. 0 g/m ² is more preferred.
The term "in terms of silver" means that the amount is converted into the mass of silver produced by reducing all the silver halide.
^The content of the specific polymer in the photosensitive layer is not particularly limited. m ² is more preferred, and 0.10 to 0.40 g/m ² is even more preferred.

<Step B>
Step B is a step of exposing the photosensitive layer and then developing it to form a fine linear silver-containing layer with a width of 2.0 μm or less containing metallic silver, gelatin, and a polymer.

By exposing the photosensitive layer, a latent image is formed in the exposed areas.
The exposure may be carried out in a pattern. For example, in order to obtain a mesh pattern composed of conductive fine lines, which will be described later, a method of exposing through a mask having a mesh-like opening pattern and scanning with a laser beam are used. and a method of exposing in a mesh pattern.
The type of light used for exposure is not particularly limited as long as it can form a latent image on silver halide, and examples thereof include visible light, ultraviolet rays, and X-rays.

By developing the exposed photosensitive layer, metallic silver is precipitated in the exposed areas (areas where the latent image is formed).
The method of development processing is not particularly limited, and examples thereof include known methods used for silver salt photographic films, photographic papers, printing plate-making films, and emulsion masks for photomasks.
A developing solution is usually used in the development processing. The type of developer is not particularly limited, and examples thereof include PQ (phenidone hydroquinone) developer, MQ (Metol hydroquinone) developer, and MAA (methol ascorbic acid) developer.

This step may further include a fixing treatment for the purpose of removing and stabilizing the silver halide in the unexposed areas.
A fixing process is performed simultaneously with and/or after development. The fixing treatment method is not particularly limited, and examples thereof include methods used for silver halide photographic films, photographic papers, printing plate-making films, and emulsion masks for photomasks.
A fixing solution is usually used in the fixing process. The type of fixing solution is not particularly limited, and examples thereof include fixing solutions described in "Shinshin no Kagaku" (written by Sasai, Shashin Kogyo Publishing Co., Ltd.) p.321.

By carrying out the above treatment, a fine linear silver-containing layer containing metallic silver, gelatin, and a specific polymer can be formed with a width of 2.0 μm or less.
Methods for adjusting the width of the silver-containing layer include, for example, adjusting the opening width of the mask used during exposure. For example, the exposure area can be adjusted by setting the opening width of the mask to 2.0 μm or less.
Moreover, when using a mask at the time of exposure, the width of the formed silver-containing layer can also be adjusted by adjusting the amount of exposure. For example, if the opening width of the mask is narrower than the target width of the silver-containing layer, the width of the region where the latent image is formed can be adjusted by increasing the exposure dose more than usual.
Furthermore, when laser light is used, the exposure area can be adjusted by adjusting the condensing range and/or scanning range of the laser light.

The width of the silver-containing layer is 2.0 μm or less, and preferably 1.4 μm or less from the viewpoint that the formed conductive fine lines are difficult to see. Although the lower limit is not particularly limited, it is preferably 0.4 μm or more, more preferably 0.8 μm or more, from the viewpoint of better conductivity of the conductive thin wire.
The silver-containing layer obtained by the above procedure is in the shape of a thin line, and the width of the silver-containing layer means the length (width) of the silver-containing layer in the direction orthogonal to the direction in which the thin line-like silver-containing layer extends. do.
In addition, a silver-containing layer having a width of 2.0 μm or less may be formed on at least a part of the support, and metal silver other than the silver-containing layer may be formed on other regions of the support. A layer comprising (eg, a layer comprising metallic silver greater than 2.0 μm in width) may be formed.

<Process C>
Step C is a step of subjecting the silver-containing layer obtained in step B to heat treatment. By carrying out this step, the fusion between the specific polymers in the silver-containing layer progresses, and the strength of the silver-containing layer is improved.

The method of heat treatment is not particularly limited, and includes a method of bringing the silver-containing layer into contact with superheated steam, and a method of heating the silver-containing layer with a temperature control device (e.g., heater). A method of contacting is preferred.

The superheated steam may be superheated steam or a mixture of superheated steam and other gas.
The contact time between the superheated steam and the silver-containing layer is not particularly limited, and is preferably 10 to 70 seconds.
The amount of superheated steam supplied is preferably 500 to 600 g/m ³ , and the temperature of the superheated steam is preferably 100 to 160°C (preferably 100 to 120°C) at 1 atmospheric pressure.

The heating conditions in the method of heating the silver-containing layer with a temperature control device are preferably 100 to 200° C. (preferably 100 to 150° C.) for 1 to 240 minutes (preferably 60 to 150 minutes).

<Process D>
Step D is a step of removing the gelatin in the silver-containing layer obtained in Step C. By carrying out this step, gelatin is removed from the silver-containing layer and spaces are formed in the silver-containing layer.

The method for removing gelatin is not particularly limited. "Also called.).

The proteolytic enzymes used in method 1 include known vegetable or animal enzymes that can hydrolyze proteins such as gelatin.
Proteolytic enzymes include, for example, pepsin, rennin, trypsin, chymotrypsin, cathepsin, papain, ficin, thrombin, renin, collagenase, bromelain and bacterial proteases, preferably trypsin, papain, ficin or bacterial proteases. .
The procedure in method 1 may be any method as long as the silver-containing layer and the protease are brought into contact with each other. A method of contacting is mentioned. Examples of the contact method include a method of immersing the silver-containing layer in the enzyme solution and a method of coating the silver-containing layer with the enzyme solution.
The content of the proteolytic enzyme in the enzyme solution is not particularly limited, and is preferably 0.05 to 20% by mass, preferably 0.5 to 0.5%, based on the total amount of the enzyme solution in terms of easy control of the degree of gelatin decomposition and removal. 10% by mass is more preferred.
The enzyme solution usually contains water in addition to the protease.
The enzyme solution may optionally contain other additives (eg, pH buffers, antimicrobial compounds, wetting agents, and preservatives).
The pH of the enzyme solution is selected so that the action of the enzyme can be maximized, and generally 5-9 is preferred.
The temperature of the enzyme solution is preferably a temperature at which the action of the enzyme is enhanced, specifically 25 to 45°C.

In addition, if necessary, after the treatment with the enzyme solution, the obtained silver-containing layer may be washed with warm water.
The washing method is not particularly limited, and is preferably a method of contacting the silver-containing layer with warm water. Examples thereof include a method of immersing the silver-containing layer in warm water and a method of applying warm water onto the silver-containing layer.
The temperature of the hot water is appropriately selected depending on the type of protease used, and is preferably 20 to 80°C, more preferably 40 to 60°C, from the viewpoint of productivity.
The contact time (washing time) between the hot water and the silver-containing layer is not particularly limited, and is preferably 1 to 600 seconds, more preferably 30 to 360 seconds, from the viewpoint of productivity.

The oxidizing agent used in Method 2 may be any oxidizing agent capable of decomposing gelatin, and an oxidizing agent having a standard electrode potential of +1.5 V or higher is preferable. Here, the standard electrode potential means the standard electrode potential (25° C., E0) with respect to the standard hydrogen electrode in the aqueous solution of the oxidizing agent.
Examples of the oxidizing agent include persulfuric acid, percarbonic acid, superphosphoric acid, hypoperchloric acid, peracetic acid, meta-chloroperbenzoic acid, hydrogen peroxide solution, perchloric acid, periodic acid, potassium permanganate, ammonium sulfate, ozone, hypochlorous acid or salts thereof, etc., but from the viewpoint of productivity and economy, hydrogen peroxide water (standard electrode potential: 1.76 V), hypochlorous acid or salts thereof are preferred, Sodium hypochlorite is more preferred.

The procedure in Method 2 may be any method as long as it is a method of bringing the silver-containing layer into contact with the oxidizing agent. A method of contacting can be mentioned. Examples of the contact method include a method of immersing the silver-containing layer in an oxidizing agent solution and a method of coating the silver-containing layer with an oxidizing agent solution.
The type of solvent contained in the oxidizing agent liquid is not particularly limited, and includes water and organic solvents.

<Process E>
Step E is a step of plating the silver-containing layer obtained in step D to obtain a conductive fine wire. By carrying out this step, a conductive fine line is formed in which the space formed by removing the gelatin is filled with a metal (plated metal). In addition, the width of the region where the metal exists is 2.0 μm or less in the vertical cross section of the conductive thin wire in the direction orthogonal to the direction in which the conductive thin wire extends.

The type of plating treatment is not particularly limited, but includes electroless plating (chemical reduction plating or displacement plating) and electroplating, with electroless plating being preferred. As the electroless plating, a known electroless plating technique is used.
The plating treatment includes, for example, silver plating treatment, copper plating treatment, nickel plating treatment, and cobalt plating treatment, and silver plating treatment or copper plating treatment is preferable in that the conductivity of the conductive thin wire is more excellent. Silver plating is more preferred.

The components contained in the plating solution used in the plating treatment are not particularly limited. metal ions for plating;2. reducing agent;3. 4. Additives (stabilizers) that improve the stability of metal ions; It mainly contains pH adjusters. In addition to these, the plating bath may contain known additives such as plating bath stabilizers.
The type of metal ions for plating contained in the plating solution can be appropriately selected according to the metal species to be deposited, and examples thereof include silver ions, copper ions, nickel ions, and cobalt ions.

The procedure of the plating treatment is not particularly limited as long as it is a method of bringing the silver-containing layer into contact with the plating solution, for example, a method of immersing the silver-containing layer in the plating solution.
The contact time between the silver-containing layer and the plating solution is not particularly limited, and is preferably 1 to 30 minutes from the standpoint of better conductivity of the conductive fine wire and productivity.

The width of the region where the metal exists is 2.0 μm or less in the vertical cross-section of the conductive fine wire obtained in step E in the direction orthogonal to the direction in which the conductive fine wire extends. Among them, 1.5 μm or less is preferable in that the conductive thin wire becomes more difficult to visually recognize. Although the lower limit is not particularly limited, it is preferably 0.5 μm or more, more preferably 1.0 μm or more, from the viewpoint of better conductivity of the conductive thin wire.
By performing the above steps A to E, the width W of the region where the metal exists is 2.0 μm or less in the vertical cross section, and the ratio of the height H to the width W of the region where the metal exists (H/W ) is greater than 0.40.
The definition of the width of the region where the metal exists and the method for measuring the width will be described later.

<Process F>
The manufacturing method of the conductive substrate of the present invention may have, after the step E, a step F of smoothing the conductive thin wires obtained in the step E.
By carrying out this step, a conductive thin wire having excellent conductivity can be obtained.

The smoothing treatment method is not particularly limited, and for example, a calendering step of passing a support having conductive thin wires through at least a pair of rolls under pressure is preferred. The smoothing treatment using the calender roll is hereinafter referred to as calender treatment.
Examples of rolls used for calendering include plastic rolls and metal rolls, and plastic rolls are preferred from the viewpoint of preventing wrinkles.
The pressure between the rolls is not particularly limited, and is preferably 2 MPa or more, more preferably 4 MPa or more, and preferably 120 MPa or less. In addition, the pressure between rolls can be measured using Prescale (for high pressure) manufactured by FUJIFILM Corporation.
The temperature of the smoothing treatment is not particularly limited, preferably 10 to 100°C, more preferably 10 to 50°C.

<Process G>
The method for manufacturing a conductive substrate of the present invention may further include a step G of heat-treating the conductive thin wire obtained in the step F after the step F. By carrying out this step, a conductive thin wire having excellent conductivity can be obtained.
The method of heat-treating the conductive fine wire is not particularly limited, and the method described in step C can be mentioned.

<Process H>
The method for producing a conductive substrate of the present invention may have, before step A, step H of forming a silver halide-free layer containing gelatin and a specific polymer on the support. By carrying out this step, a silver halide-free layer is formed between the support and the silver halide-containing photosensitive layer. This silver halide-free layer plays the role of a so-called antihalation layer and contributes to improving the adhesion between the conductive layer and the support.
The silver halide-free layer contains gelatin and the specific polymer described above. On the other hand, the silver halide-free layer does not contain silver halide.
The ratio of the mass of the specific polymer to the mass of gelatin (mass of the specific polymer/mass of gelatin) in the silver halide-free layer is not particularly limited, and is preferably 0.1 to 5.0. 0 to 3.0 is more preferable.
The content of the specific polymer in the silver halide-free layer is not particularly limited, and is often 0.03 g/m ² or ^more . The above is preferable. Although the upper limit is not particularly limited, it is often 1.63 g/m ² or less.

The method of forming the silver halide-free layer is not particularly limited, and for example, a method of coating a layer-forming composition containing gelatin and a specific polymer on a support and, if necessary, heat-treating it. mentioned.
The layer-forming composition may contain a solvent, if necessary. The type of solvent is exemplified by the solvent used in the photosensitive layer-forming composition described above.
The thickness of the silver halide-free layer is not particularly limited, and is often 0.05 μm or more, preferably more than 1.0 μm, more preferably 1.5 μm or more, from the viewpoint of better adhesion of the conductive fine wires. Although the upper limit is not particularly limited, it is often 3.0 μm or less.

<Process I>
The method for producing a conductive substrate of the present invention has a step I of forming a protective layer containing gelatin and a specific polymer on the silver halide-containing photosensitive layer after step A and before step B. may By providing a protective layer, the scratch resistance and mechanical properties of the photosensitive layer can be improved.
The ratio of the mass of the specific polymer to the mass of gelatin in the protective layer (mass of the specific polymer/mass of gelatin) is not particularly limited, and is preferably more than 0 and 2.0 or less, more than 0 and 1.0 or less. more preferred.
Moreover, the content of the specific polymer in the protective layer is not particularly limited, and is preferably more than 0 g/m ² and not more than 0.3 g/m ² , more preferably 0.005 to 0.1 g/m ² .

The method of forming the protective layer is not particularly limited, and for example, a method of coating a protective layer-forming composition containing gelatin and a specific polymer on the silver halide-containing photosensitive layer and, if necessary, heat-treating it. is mentioned.
The protective layer-forming composition may contain a solvent, if necessary. The type of solvent is exemplified by the solvent used in the photosensitive layer-forming composition described above.
The thickness of the protective layer is not particularly limited, preferably 0.03 to 0.3 μm, more preferably 0.075 to 0.20 μm.

In addition, the process H, the process A, and the process I mentioned above may be performed simultaneously by simultaneous multi-layer coating.

<Conductive substrate>
The structure of the conductive substrate obtained by the manufacturing method of the conductive substrate of the present invention will be described below.
FIG. 1 shows a cross-sectional view of a first embodiment of the conductive substrate of the present invention.
The conductive substrate 10 includes a support 12 and conductive fine lines 14A arranged on the support 12. As shown in FIG. Although two conductive thin wires 14A are shown in FIG. 1, the number is not particularly limited.
FIG. 2 shows a vertical cross section of the conductive thin wire 14A in a direction perpendicular to the extending direction of the conductive thin wire 14A. The vertical cross section of the conductive fine wire is a cross section taken along a plane perpendicular to the direction in which the conductive fine wire 14A extends. That is, the vertical cross section of the conductive thin wire is a cross section obtained by cutting along a plane perpendicular to the surface of the conductive thin wire 14A along a direction perpendicular to the direction in which the conductive thin wire 14A extends.
The conductive fine wire 14A contains the polymer 16 and the metal 18, and as shown in FIG. That is, as shown in FIG. 2, the metal 18 has a small amount of distribution in a region near the surface 114A side of the conductive thin wire 14A or a region near the surface 214A side, and a distribution amount near the intermediate region of the conductive thin wire 14A. tend to be many. The shape of the metal 18 is not limited to a particulate form, and may be, for example, a form that is partially or wholly bonded by fusion.

Next, the width and height of the region where the metal exists in the vertical cross section of the conductive thin wire will be described with reference to FIG.
As shown in FIG. 2, the width W of the region where the metal 18 exists corresponds to the distance between the metals 18 that are farthest along the width direction of the conductive thin wire 14A in the vertical cross section of the conductive thin wire 14A. .
Further, the height H of the region where the metal 18 is present means, as shown in FIG. correspond to distance.
The width W of the region where the metal exists in the vertical cross section of the conductive thin wire can be measured in the same manner as the thickness of the conductive thin wire described later. In the present invention, the conductive substrate surface is observed with a scanning electron microscope, Select one extending conductive thin line, select 5 arbitrary points of the selected one conductive thin line, and metal is present at each point at intervals of 200 nm in the direction in which the conductive thin line extends. The width W of the region where the metal exists is obtained by measuring the width of the region at 20 points and arithmetically averaging a total of 100 measured points. That is, the width W of the region in which the metal is present as defined above corresponds to the average value.
In addition, as the measurement method using the scanning electron microscope, first, in order to impart conductivity to the surface of the conductive fine wire, carbon deposition is performed on the surface of the conductive fine wire, and a scanning electron microscope (Hitachi High-Technologies Co., Ltd. S -5200 type SEM), it is possible to observe the width of the region where the metal exists inside the conductive fine wire. Observation conditions are the secondary electron mode and an acceleration voltage of 10 kV.
In addition, the height H of the region where the metal of the conductive thin line exists is the direction in which the conductive thin line extends at any 10 points of the same single conductive thin line selected when measuring the width W. Observe and measure the cross section in the orthogonal direction, measure the height H in each cross section, and calculate the arithmetic mean of them. In other words, the height H of the region where the metal of the conductive thin wire exists corresponds to the average value.
At this time, observation of the vertical cross section of the conductive fine wire is performed with a scanning electron microscope, and an acceleration voltage that provides a contrast between the polymer and the metal is selected. More specifically, as a method for observing the vertical cross section of the conductive thin wire, after cutting the vertical cross section of the conductive thin wire with a microtome, carbon deposition is performed on the exposed vertical cross section to impart conductivity, and a scanning type is used. A vertical cross section is observed with an electron microscope (S-5200 type SEM manufactured by Hitachi High-Technologies Corporation). Observation conditions are backscattered electron mode and an acceleration voltage of 5 kV.

The width W of the region where the metal is present in the vertical cross section of the conductive thin wire is 2.0 μm or less, and preferably 1.5 μm or less in terms of making the conductive thin wire less visible. Although the lower limit is not particularly limited, it is preferably 0.5 μm or more, more preferably 1.0 μm or more, from the viewpoint of better conductivity of the conductive thin wire.
Here, the line thickness obtained by taking the ratio of the width W of the conductive thin line after plating to the width of the silver-containing layer before plating is 1.5 or less in that the conductive thin line becomes more difficult to visually recognize. is preferred, and 1.2 or less is more preferred.
The ratio (H/W) of the height H to the width W of the region where the metal exists in the vertical cross section of the conductive thin wire is more than 0.40, and the conductive thin wire has better conductivity, so 0.60 0.80 or more is more preferable, and 0.86 or more is even more preferable. Although the upper limit is not particularly limited, it is preferably 1.20 or less, more preferably 1.00 or less, in terms of improving resistance to external pressure.
In addition, the height H of the region where the metal exists in the vertical cross section of the conductive fine wire is not particularly limited as long as the above ratio is satisfied, but it is preferably 0.5 to 2.5 μm, more preferably 1.0 to 2.0 μm. .

Conductive wires include polymers and metals.
The type of polymer is not particularly limited, and known polymers can be used. Among them, the above-mentioned specific polymer is preferable.
The metal is a part that secures the conductive properties of the conductive thin wire. In addition to silver derived from the silver halide-containing photosensitive layer described above, metals imparted by plating include silver (metallic silver), copper (metallic copper), gold (metallic gold ), nickel (metallic nickel), palladium (metallic palladium), or a mixture of two or more thereof, more preferably silver, copper, or a mixture thereof, and still more preferably silver.
In FIG. 2, the metal particles are dispersed in the polymer, but the present invention is not limited to this form. There may be.

The line width of the conductive thin line is usually 2.0 μm or less in many cases. Among them, the thickness is preferably 1.5 μm or less from the viewpoint that the conductive thin line is hardly visible. Although the lower limit is not particularly limited, it is preferably 0.5 μm or more, more preferably 1.2 μm or more, from the viewpoint of better conductivity of the conductive thin wire.
The line width of the conductive thin line is the width represented by Wa in FIG.
Although the thickness of the conductive thin wire is not particularly limited, it is preferably 0.5 to 2.5 μm, more preferably 1.0 to 2.0 μm.

The wire resistance value of the conductive thin wire is required to be less than 200Ω/mm. Among them, from the viewpoint of operability when used as a touch panel, it is preferably less than 100Ω/mm, more preferably less than 80Ω/mm.
The line resistance value is obtained by dividing the resistance value measured by the four-probe method by the distance between the measurement terminals. More specifically, after disconnecting both ends of any one conductive fine wire constituting the mesh pattern and separating it from the mesh pattern, four (A, B, C, D) microprobes (Micro Support Co., Ltd. A tungsten probe (diameter 0.5 um)) is brought into contact with the separated conductive thin wire, and a source meter (Keithley source meter 2400 general-purpose source meter) is used for the outermost probes A and D to measure the inner probe B, A constant current I is applied so that the voltage V between C becomes 5 mV, the resistance value R=V/I is measured, and the obtained resistance value R is divided by the distance between B and C to obtain the wire resistance value.

The conductive thin wire may form a predetermined pattern, for example, the pattern is not particularly limited, triangular such as equilateral triangle, isosceles triangle, right triangle, square, rectangle, rhombus, parallelogram, trapezoid, etc. Square, (positive) hexagon, (positive) octagon and other (positive) n-sided polygons, circles, ellipses, and geometric figures that combine star shapes are preferable, and in a mesh shape (mesh pattern) It is more preferable to have
By mesh-like is intended a shape including a plurality of square openings (lattice) 20 constituted by intersecting thin conductive wires 14B, as shown in FIG.

The length L of one side of the opening 20 is not particularly limited, but is preferably 1500 μm or less, more preferably 1300 μm or less, even more preferably 1000 μm or less, preferably 5 μm or more, more preferably 30 μm or more, and further preferably 80 μm or more. preferable. When the length of the side of the opening is within the above range, it is possible to maintain good transparency, and when the conductive substrate is attached to the front surface of the display device, the display can be visually recognized without discomfort. can be done.
From the viewpoint of visible light transmittance, the aperture ratio of the mesh pattern is preferably 90.00% or more, more preferably 95.00% or more, and even more preferably 99.50% or more. Although the upper limit is not particularly limited, it may be less than 100%.
The aperture ratio corresponds to the ratio of the area on the support excluding the area where the conductive fine lines are present in the mesh pattern area to the entire area.

<Application>
The conductive substrate obtained as described above can be applied to various applications such as touch panels (or touch panel sensors), semiconductor chips, various electric wiring boards, FPCs (Flexible Printed Circuits), COFs (Chip on Film), It can be applied to various uses such as TAB (Tape Automated Bonding), antennas, multilayer wiring boards, and motherboards. Among others, the conductive substrate of the present invention is preferably used for a touch panel (capacitive touch panel).
When the conductive substrate of the present invention is used for a touch panel, the conductive fine lines described above can effectively function as detection electrodes.
The conductive substrate may have a conductive portion having a width of more than 2.0 μm in the region where the metal exists, in addition to the conductive thin wire having the predetermined characteristics described above. This conductive portion may be connected to the conductive fine wire described above to conduct.

EXAMPLES The present invention will be described more specifically below with reference to Examples of the present invention. It should be noted that the materials, usage amounts, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the specific examples shown below.

<Example 1>
(Preparation of silver halide emulsion)
Liquid 1 below was kept at 38° C. and pH 4.5, and 90% of each of liquids 2 and 3 below was added simultaneously over 20 minutes with stirring to liquid 1 to form core particles of 0.16 μm. formed. Subsequently, Liquids 4 and 5 below were added to the resulting solution over 8 minutes, and the remaining 10% of Liquids 2 and 3 below were added over 2 minutes to grow the core particles to 0.21 μm. let me Further, 0.15 g of potassium iodide was added to the resulting solution and aged for 5 minutes to complete grain formation.

Liquid 1:
750 ml of water
8.6g gelatin
3 g of sodium chloride
1,3-dimethylimidazolidine-2-thione 20 mg
Sodium benzenethiosulfonate 10mg
0.7 g of citric acid
Two liquids:
300ml water
150g of silver nitrate
3 fluids:
300ml water
38g sodium chloride
Potassium bromide 32g
Potassium hexachloroiridate (III) (0.005% KCl 20% aqueous solution) 5 ml
Ammonium hexachlororhodate
(0.001% NaCl 20% aqueous solution) 7 ml
4 fluids:
100ml water
50g silver nitrate
5 fluids:
100ml water
13 g sodium chloride
Potassium bromide 11g
yellow blood salt 5mg

After that, it was washed with water by a flocculation method according to a conventional method. Specifically, the temperature of the solution obtained above was lowered to 35° C., and the pH was lowered using sulfuric acid until the silver halide precipitated (the pH was in the range of 3.6±0.2). Next, about 3 liters of the supernatant liquid was removed from the obtained solution (first water washing). Next, 3 liters of distilled water was added to the decanted solution, followed by sulfuric acid until the silver halide precipitated. Again, 3 liters of the supernatant was removed from the obtained solution (second water washing). The same operation as the second water washing was repeated once more (third water washing) to complete the water washing and desalting steps. After washing and desalting, the emulsion was adjusted to pH 6.4 and pAg 7.5, and 2.5 g of gelatin, 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate and 10 mg of chloroauric acid were added, Chemical sensitization was applied at 55°C for optimum sensitivity. Thereafter, 100 mg of 1,3,3a,7-tetraazaindene as a stabilizer and 100 mg of Proxel (trade name, manufactured by ICI Co., Ltd.) as a preservative were added to the obtained emulsion. The finally obtained emulsion contains 0.08 mol % of silver iodide, and the ratio of silver chlorobromide is 70 mol % of silver chloride and 30 mol % of silver bromide, and has an average grain size (equivalent sphere diameter). It was an emulsion of silver chlorobromide cubic grains of 200 nm and a coefficient of variation of 9%.

(Preparation of composition for forming photosensitive layer)
1,3,3a,7-tetraazaindene (1.2×10 ⁻⁴ mol/mol Ag), hydroquinone (1.2×10 ⁻² mol/mol Ag), citric acid (3.0× 10 ⁻⁴ mol/mol Ag), 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt (0.90 g/mol Ag), and a trace amount of hardener were added to form the composition. got The pH of the composition was then adjusted to 5.6 using citric acid.
A dispersing agent comprising a polymer represented by the following (P-1) (hereinafter also referred to as "polymer 1") and a dialkylphenyl PEO (PEO is an abbreviation for polyethylene oxide) sulfate ester is added to the above composition. and water (the ratio of the mass of the dispersant to the mass of the polymer 1 (mass of the dispersant/mass of the polymer 1, the unit is g/g) is 0.02, and the solid content is The amount is 22% by mass.), and the ratio of the mass of polymer 1 to the total mass of gelatin in the composition (mass of polymer 1/mass of gelatin, unit g/g) is 0.25/1 was added to obtain a polymer latex-containing composition. Here, in the polymer latex-containing composition, the ratio of the mass of gelatin to the mass of silver derived from silver halide (mass of gelatin/mass of silver derived from silver halide, the unit is g/g) is 0.5. was 11.
Furthermore, EPOXY RESIN DY 022 (trade name: manufactured by Nagase ChemteX Corporation) was added as a cross-linking agent. The amount of the cross-linking agent added was adjusted so that the amount of the cross-linking agent in the silver halide-containing photosensitive layer described later was 0.09 g/m ² .
A composition for forming a photosensitive layer was prepared as described above.
Polymer 1 was synthesized with reference to Japanese Patent No. 3305459 and Japanese Patent No. 3754745.

The above polymer latex was applied to a 40 μm polyethylene terephthalate film (“Rolled long film manufactured by Fuji Film Co., Ltd.”) to form a 0.05 μm thick undercoat layer. This treatment was performed by roll-to-roll, and each of the following treatments (steps) was also performed by roll-to-roll. At this time, the width of the roll was 1 m and the length was 1000 m.

(Step H1, Step A1, Step I1)
Next, on the undercoat layer, a protective layer is formed by mixing a silver halide-free layer-forming composition obtained by mixing the polymer latex and gelatin, the photosensitive layer-forming composition, the polymer latex and gelatin. and the composition for the second layer were coated simultaneously to form a silver halide-free layer, a silver halide-containing photosensitive layer and a protective layer on the undercoat layer.
The thickness of the silver halide-free layer was 2.0 μm, and the mixing mass ratio of the polymer 1 and gelatin (polymer 1/gelatin) in the silver halide-free layer was 2/1. The content of molecule 1 was 1.3 g/m ² .
The silver halide-containing photosensitive layer had a thickness of 2.5 μm, and the mixing mass ratio of polymer 1 and gelatin (polymer 1/gelatin) in the silver halide-containing photosensitive layer was 0.25/1. and the content of polymer 1 was 0.19 g/m ² .
The thickness of the protective layer was 0.15 μm, the mixing mass ratio of polymer 1 and gelatin (polymer 1/gelatin) in the protective layer was 0.1/1, and the content of polymer 1 was It was 0.015 g/m ² .

(Step B1)
The photosensitive layer prepared above was exposed to parallel light from a high-pressure mercury lamp as a light source through a grid-like photomask. As the photomask, the mask for pattern formation shown in FIG. 3 was used. The line width of the unit square lattice forming the lattice was 1.2 μm, and the length L of one side of the lattice (opening) was 600 μm. .

After exposure, the obtained sample was developed with a developer described later, and further developed using a fixer (trade name: N3X-R for CN16X: manufactured by Fuji Film Co., Ltd.). After rinsing with pure water and drying, a sample A having a silver-containing layer containing metallic silver formed in a mesh pattern was obtained. In sample A, a conductive mesh pattern area with a size of 21.0 cm×29.7 cm was formed.

(Composition of developer)
The following compounds are contained in 1 liter (L) of developer.
Hydroquinone 0.037mol/L
N-methylaminophenol 0.016mol/L
Sodium metaborate 0.140mol/L
Sodium hydroxide 0.360mol/L
Sodium bromide 0.031mol/L
Potassium metabisulfite 0.187mol/L

Sample A obtained above was immersed in hot water at 50° C. for 180 seconds. After that, water was removed by an air shower, and the substrate was dried naturally.

(Step C1)
Sample A obtained in step B1 was carried into a superheated steam treatment tank at 110° C. and allowed to stand still for 30 seconds for superheated steam treatment. The steam flow rate at this time was 100 kg/h.

(Step D1)
Sample A obtained in step C1 was immersed in a hypochlorous acid-containing aqueous solution (25° C.) for 30 seconds. The sample A was taken out from the aqueous solution, and washed by immersing the sample A in hot water (liquid temperature: 50° C.) for 120 seconds. After that, water was removed by an air shower, and the substrate was dried naturally.
The hypochlorous acid-containing aqueous solution used was prepared by diluting Kitchen Haiter manufactured by Kao Corporation twice before use.

(Step E1)
Sample A obtained in step D1 was immersed in plating solution A (30° C.) having the following composition for 5 minutes. The sample A was taken out from the plating solution A, and washed by immersing the sample A in hot water (liquid temperature: 50° C.) for 120 seconds.
The composition of plating solution A (total amount: 1200 ml) was as follows. The pH of plating solution A was 9.5, and was adjusted by adding a predetermined amount of potassium carbonate (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). In addition, all of the following components used were manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.
(Composition of plating solution A)
- _AgNO3 8.8g
・Sodium sulfite 72g
・ Sodium thiosulfate pentahydrate 66g
・ Potassium iodide 0.004g
・Citric acid 12g
・Methylhydroquinone 3.67g
・Potassium carbonate prescribed amount ・Remainder of water

(Process F1)
Sample A obtained in step E1 was subjected to calendering at a pressure of 30 kN using a calendering device with a combination of metal rollers and resin rollers. Calendering was performed at room temperature.

(Step G1)
The sample A obtained in step F1 was transferred to a superheated steam treatment tank at 110° C. and allowed to stand still for 30 seconds for superheated steam treatment. The steam flow rate at this time was 100 kg/h. The resulting conductive mesh pattern region was a mesh layer formed of conductive fine lines, as shown in FIG. The line width of the conductive thin wire was 1.4 μm, and the thickness of the conductive thin wire was 1.2 μm.
The width of the metal-containing region in the conductive thin wire was 1.3 μm, the height was 1.1 μm, and the ratio of the height to the width of the metal-containing region was 0.85. The width and height of the region where the metal exists were measured by the method described above.

<Examples 2-10, Example 13, Comparative Examples 1-2>
A conductive substrate was obtained according to the same procedure as in Example 1, except that various conditions were changed to adjust various configurations in Table 1, as shown in Table 1, which will be described later.
"Hypochlorous acid treatment" in the degelatinization treatment in Table 1 means the treatment of step D1 carried out in Example 1, and "enzyme treatment" means that the following treatments were carried out.
(enzyme treatment)
Sample A obtained in step C1 was immersed in an aqueous protease solution (40° C.) for 120 seconds. The sample A was taken out from the protease aqueous solution, and washed by immersing the sample A in warm water (liquid temperature: 50°C) for 120 seconds. After that, water was removed by an air shower, and the substrate was dried naturally.
In addition, the protease aqueous solution used was prepared according to the following procedures.
Triethanolamine and sulfuric acid were added to an aqueous solution (concentration of protease: 0.5% by mass) of protease (Bioplase 30 L manufactured by Nagase Chemtex Co., Ltd.) to adjust the pH to 8.5.

The compositions of plating solution B (total amount: 1200 ml), plating solution C (total amount: 1000 ml), and plating solution D (total amount: 1000 ml) in Table 1 are as follows.
The pH of plating solutions B and D was 9.5, and was adjusted by adding a predetermined amount of potassium carbonate.
The pH of plating solution C was 12.2, and was adjusted by adding a predetermined amount of sodium hydroxide.
In addition, all of the following components used were manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.
(Plating solution B)
- _AgNO3 8.8 g
・Sodium sulfite 72g
・ Sodium thiosulfate pentahydrate 66g
・ Potassium iodide 0.004 g
・1,2,4-trihydroxybenzene 1.9g
・Potassium carbonate prescribed amount ・Remainder of water (plating solution C)
・ 10 g of copper sulfate pentahydrate
・40 g of disodium ethylenediaminetetraacetate
・Formalin (concentration 37%) 3ml
・9 g of sodium hydroxide
・Bipyridyl 0.01g
・Polyethylene glycol 0.01g
・Predetermined amount of sodium hydroxide ・Remainder of water (composition of plating solution D)
- _AgNO3 8.8 g
・Sodium sulfite 72g
・ Sodium thiosulfate pentahydrate 66g
・ Potassium iodide 0.004 g
・Citric acid 12g
・Methylhydroquinone 3.67g
・Phenidone 1.2g
- Predetermined amount of potassium carbonate - Remainder of water In addition, as described later, in Comparative Example 1, step D1 was not carried out.

<Example 11>
In the preparation of the silver halide emulsion of Example 1, the temperature of solution 1 was changed to 30°C, and 8.93 g of potassium bromide was used in place of sodium chloride, so that the ratio of silver chlorobromide was changed to 70% silver chloride. The procedure of Example 1 was repeated except that a silver chlorobromide cubic grain emulsion having an average grain diameter (equivalent sphere diameter) of 120 nm and a coefficient of variation of 9% was prepared and used at 30 mol % silver bromide. A conductive substrate was obtained according to

<Example 12>
A conductive substrate was obtained in the same manner as in Example 2, except that the smoothing treatment in step F was not performed.

<Comparative Example 3>
A conductive substrate was obtained in the same manner as in Example 6, except that the order of the degelatinization treatment in step D and the plating solution immersion treatment in step E was reversed.

<Evaluation>
(Conductivity)
The line resistance value of the conductive mesh pattern area of the obtained conductive substrate was measured. The line resistance value is obtained by dividing the resistance value measured by the four-probe method by the distance between the measurement terminals. More specifically, after disconnecting both ends of any one conductive fine wire constituting the mesh pattern and separating it from the mesh pattern, four (A, B, C, D) microprobes (Micro Support Co., Ltd. A tungsten probe (diameter 0.5 μm)) was brought into contact with the separated conductive thin wire, and the outermost probes A and D were separated by 250 μm using a source meter (KEITHLEY source meter, 2400 general-purpose source meter). A constant current I is applied so that the voltage V between the internal probes B and C is 5 mV, the resistance value R = V / I is measured, and the obtained resistance value R is divided by the distance between B and C to obtain the line resistance sought the value. The obtained resistance value R was divided by the distance between B and C to obtain the line resistance value, and the average value of the measured values at arbitrary 10 points was evaluated as conductivity according to the following criteria. The results are summarized in Table 1. In addition, as an evaluation, 3 or more is preferable, 4 or more is more preferable, and 5 or more is further preferable.
5: The wire resistance value is less than 60Ω/mm.
4: The wire resistance value is 60Ω/mm or more and less than 80Ω/mm.
3: The wire resistance value is 80Ω/mm or more and less than 100Ω/mm.
2: The wire resistance value is 100Ω/mm or more and less than 200Ω/mm.
1: The wire resistance value is 200Ω/mm or more.

(Visibility)
The resulting conductive substrate was laminated in the order of glass/conductive substrate/polarizing plate/polarizing plate (direction in which the plane of polarization is orthogonal)/black PET (manufactured by Panac Co., Ltd., industrial black PET (GPH100E82A04)). , to obtain a laminate. The conductive substrate was placed so that the conductive mesh pattern was positioned on the glass side.
Next, the obtained laminate was visually observed by 10 observers from the front of the glass surface side and at an angle of 30° to 60° under ambient light of 500 lux, according to the following criteria. ,evaluated. The results are summarized in Table 1. The evaluation is preferably 3 or more, more preferably 4 or more, and even more preferably 5. When the mesh pattern is difficult to see, the optical properties are excellent, and moiré generated when the conductive substrate is laminated on the display is reduced.
5: No mesh pattern was visible when the conductive substrate was observed from a distance of 15 cm.
4: None or one observer visually recognized the mesh pattern when observing the conductive substrate from a position 30 cm away.
3: Two to four observers visually recognized the mesh pattern when observing the conductive substrate from a position 30 cm away.
2: Five or more observers visually recognized the mesh pattern when observing the conductive substrate from a position 30 cm away.
Five or more observers visually recognized the mesh pattern when observing the conductive substrate from a position 1:50 cm away.

(Transmittance)
The total light transmittance of the conductive mesh pattern area of the obtained conductive substrate was measured with a haze meter NDH 7000 manufactured by Nippon Denshoku Industries and evaluated according to the following criteria. The results are summarized in Table 1. In addition, when the total light transmittance is high, the image quality of the display is improved, and the power consumption of the display in which the conductive substrates are laminated can be suppressed. The evaluation is preferably 3 or more, more preferably 4 or more, and even more preferably 5.
5: Total light transmittance is 85% or more 4: Total light transmittance is 80% or more and less than 85% 3: Total light transmittance is 75% or more and less than 80% 2: Total light transmittance is 70% or more and less than 75% 1 : Total light transmittance is less than 70%

(Adhesion)
The conductive mesh pattern area of the obtained conductive substrate was immersed in pure water at 25° C. and scratched with a sapphire needle (φ1.0) under a load of 40 g. In addition, it is a direction orthogonal to the direction in which the conductive thin wire extends, and the scratching is performed over 10 cm so as to intersect the conductive thin wire, and arbitrary three points are extracted from the range, and optical A scratch range of 1 cm was observed at each location using a microscope, and the adhesion was evaluated according to the following criteria. In addition, as an evaluation, 3 or more is preferable, 4 or more is more preferable, and 5 is still more preferable. Here, "distortion" refers to deformation such as bending or chipping of the conductive thin wire.
5: No distortion occurs.
4: Distortion occurs at 1 point out of 3 points.
3: Distortion occurs at 2 points out of 3 points.
2: Distortion occurs at 3 out of 3 points.
1: There is a portion where the conductive thin wire is peeled off and torn.

(Wet heat resistance change)
The rate of change in the line resistance value before and after the conductive mesh pattern of the obtained conductive substrate was allowed to stand in a moist heat atmosphere of 60° C. and 90% RH for 10 days {(Line resistance value after standing − Before standing (line resistance value)/line resistance value before standing} was evaluated as a wet heat resistance change according to the following criteria. In addition, as an evaluation, 3 or more is preferable, 4 or more is more preferable, and 5 is still more preferable.
5: The rate of change is less than 3% 4: The rate of change is 3% or more and less than 5% 3: The rate of change is 5% or more and less than 10% 2: The rate of change is 10% or more and less than 20% 1: The rate of change is 20% or more

"Polymer 1 content (g/m ² )" in Table 1 represents the content (g/m ² ) of Polymer 1 in the silver halide-free layer, and "Thickness (μm)" It represents the thickness of the silver halide-free layer.
"Plating metal type" in Table 1 indicates the type of metal deposited by plating.
"Plating solution" in Table 1 indicates the type of plating solution used.
"Plating time" in Table 1 represents the immersion time in the plating solution.
"Silver-containing layer width [μm]" in Table 1 represents the width of the silver-containing layer obtained after exposure and development.
“Width W [μm]” and “Height H [μm]” in Table 1 represent the width and height of the region where the metal exists in the vertical cross section of the conductive thin wire.
"Aperture ratio" in Table 1 represents the aperture ratio of the conductive mesh pattern region in the obtained conductive substrate.

As shown in Table 1, it was confirmed that the manufacturing method and the conductive substrate of the present invention provided desired effects.
From the comparison of Examples 1 to 3, it was confirmed that when H/W is 0.86 or more, the conductivity is more excellent.
Further, from Examples 4 and 5, it was confirmed that when the width W was less than 1.3 μm, the visibility was more excellent.
Further, from a comparison between Examples 7 and 8 and Comparative Example 2, it was confirmed that wire thickening is less likely to occur and conductivity and visibility are more excellent when the plating metal type is silver.
From a comparison between Examples 2 and 10, it was confirmed that adhesion was improved when the thickness of the silver halide-free layer was more than 1.0 µm.
Further, from a comparison of Examples 1 and 11, it was confirmed that when the equivalent sphere diameter of the silver halide is small (50 to 150 nm), the height of the conductive fine lines increases and the conductivity improves. In addition, it was confirmed that the uniformity of the line width of the conductive fine wire was increased, and furthermore, the resistance change in the case of moist heat aging could be suppressed.
Moreover, it was confirmed from the comparison between Example 2 and Example 12 that the conductivity was further improved when the smoothing treatment was performed.
In addition, by comparing Example 6 and Comparative Example 3, the binder is removed from the silver-containing layer and pores are formed, which makes it difficult for the line to thicken during plating, and is excellent in both conductivity and visibility. was confirmed.

REFERENCE SIGNS LIST 10 conductive substrate 12 substrate 14A, 14B conductive thin wire 16 polymer 18 metal 20 opening

Claims (16)

Step A of forming on a support a silver halide-containing photosensitive layer containing silver halide, gelatin, and a polymer different from the gelatin;
After exposing the silver halide-containing photosensitive layer, it is developed to form a fine linear silver-containing layer having a width of 2.0 μm or less containing metallic silver, the gelatin, and a polymer different from the gelatin. Forming step B;
a step C of subjecting the silver-containing layer obtained in the step B to a heat treatment;
a step D of removing the gelatin in the silver-containing layer obtained in the step C;
A step E of plating the silver-containing layer obtained in the step D to form a conductive thin wire;
has
the conductive thin wire contains a polymer and a metal,
The width of the region where the metal is present is 2.0 μm or less in a vertical cross section of the conductive thin wire in a direction perpendicular to the direction in which the conductive thin wire extends ,
A conductive substrate, wherein the ratio of the height to the width of the region where the metal exists is 0.80 or more in the vertical cross section of the conductive thin wire in the direction orthogonal to the direction in which the conductive thin wire extends. Production method. 2. The method for producing a conductive substrate according to claim 1, wherein the silver halide is particles having an equivalent spherical diameter of 10 to 200 nm. 3. The method for manufacturing a conductive substrate according to claim 1, wherein said plating treatment is silver plating treatment or copper plating treatment. 4. The method for manufacturing a conductive substrate according to claim 3, wherein the plating treatment is silver plating treatment. 2. Said support has on its surface a silver halide-free layer containing no silver halide, containing gelatin and a polymer different from said gelatin, and having a thickness of more than 1.0 μm. 5. The method for producing a conductive substrate according to any one of items 1 to 4. The method for producing a conductive substrate according to any one of claims 1 to 5, wherein the step C is a step of bringing the silver-containing layer obtained in the step B into contact with superheated steam. The method for producing a conductive substrate according to any one of claims 1 to 6, further comprising a step F of smoothing the conductive thin wires obtained in the step E. 8. The method of manufacturing a conductive substrate according to claim 7, further comprising a step G of heat-treating the conductive thin wires obtained in step F after step F. 8. The ratio of the height to the width of the region where the metal exists is 0.86 or more in a vertical cross section of the conductive thin wire in a direction perpendicular to the direction in which the conductive thin wire extends. The method for manufacturing a conductive substrate according to any one of 1. 10. The method according to any one of claims 1 to 9, wherein the height of the region where the metal exists is 1.2 to 1.4 μm in a vertical cross section of the conductive thin wire in a direction perpendicular to the direction in which the conductive thin wire extends. A method for manufacturing a conductive substrate according to any one of the items. 11. The conductive thin line according to any one of claims 1 to 10, wherein the step E fills the space in the silver-containing layer formed by removing the gelatin in the step D with the metal. 2. A method for producing a conductive substrate according to item 1. a support;
a conductive thin wire containing a polymer and a metal disposed on the support;
In a vertical cross section of the conductive thin wire in a direction perpendicular to the direction in which the conductive thin wire extends, the width of the region where the metal exists is 2.0 μm or less,
A conductive substrate, wherein, in the vertical section, the ratio of height to width of the region where the metal is present is 0.80 or more . 13. The conductive substrate according to claim 12 , wherein said conductive fine lines form a mesh pattern. 14. The conductive substrate according to claim 13 , wherein the mesh pattern has an aperture ratio of 95.00% or more. 14. A ratio of height to width of the region in which the metal is present in a vertical cross section of the conductive thin wire in a direction perpendicular to the direction in which the conductive thin wire extends is 0.86 or more. The conductive substrate according to any one of . 16. The method according to any one of claims 12 to 15, wherein the height of the region where the metal exists is 1.2 to 1.4 μm in a vertical cross section of the conductive thin wire in a direction perpendicular to the direction in which the conductive thin wire extends. A method for manufacturing a conductive substrate according to any one of the items.

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