JP7324299B2 - Plating solution, plating set, manufacturing method of conductive substrate - Google Patents

Description

The present invention relates to a plating solution, a plating set, and a method for manufacturing 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 increasing.

A plating method is mentioned as a method of manufacturing a conductive fine wire. Patent Document 1 discloses a plating solution containing silver ions and an aminocarboxylic acid compound.

JP 2005-042166 A

On the other hand, in recent years, the thinning of conductive thin wires has progressed, and the space width between conductive thin wires is also being designed to be narrower in an increasing number of cases.
The inventors of the present invention use the plating solution described in Patent Document 1 to form a conductive pattern having a narrow space width between the conductive fine lines as described above. Although the conductive fine lines have excellent conductivity, It was found that short circuits tend to occur between conductive thin wires.

In view of the above-mentioned circumstances, the present invention is capable of forming conductive thin wires exhibiting excellent conductivity and causing short circuits between formed conductive thin wires (especially between conductive thin wires with an interval of 30 μm or less). An object of the present invention is to provide a plating solution capable of suppressing the
Another object of the present invention is to provide a plating set and a method for manufacturing a conductive substrate.

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) A plating solution containing a silver salt, a polymer having a carboxyl group or a salt thereof, and water,
A plating solution in which the content of a polymer having a carboxyl group or a salt thereof is 5.0% by mass or less with respect to the total mass of the plating solution.
(2) The plating solution according to (1), wherein the polymer having a carboxyl group or a salt thereof has a weight average molecular weight of 2,000 to 1,000,000.
(3) The plating solution according to (1) or (2), wherein the polymer having a carboxyl group or salt thereof has a weight average molecular weight of 2,000 to 500,000.
(4) The plating solution according to any one of (1) to (3), wherein the ratio of the weight of the silver salt in terms of silver to the weight of the polymer having a carboxyl group or salt thereof is 0.10 to 5.0.
(5) The plating solution according to any one of (1) to (4), further containing a reducing agent.
(6) A plating set comprising the plating solution according to any one of (1) to (4) and a reducing solution containing a reducing agent.
(7) forming a fine-line silver-containing layer on the support;
The thin wire-shaped silver-containing layer is subjected to plating using the plating solution described in any one of (1) to (5) or the plating set described in (6) to form a conductive thin wire. and forming a conductive substrate.
(8) a plurality of conductive thin wires are arranged parallel to each other;
The method for producing a conductive substrate according to (7), wherein there is a region in which the distance between adjacent conductive fine lines is 30 μm or less.
(9) A mesh pattern is formed by conductive fine wires,
The method for producing a conductive substrate according to (7), wherein the line width of the conductive thin line is 0.5 μm or more and less than 4.0 μm.

According to the present invention, it is possible to form a conductive thin wire that exhibits excellent conductivity, and to suppress the occurrence of short circuits between the formed conductive thin wires (especially between conductive thin wires with an interval of 30 μm or less). Plating solution can be provided.
Further, according to the present invention, it is possible to provide a plating set and a method for manufacturing a conductive substrate.

FIG. 4 is a partial plan view showing a mesh pattern; FIG. 4 is a partial plan view showing a state in which thin-line silver-containing layers are arranged in parallel. 1 is a cross-sectional view of a conductive substrate; FIG. FIG. 4 is a diagram for explaining a comb-tooth pattern region;

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 is that a predetermined amount of a polymer having a carboxyl group or a salt thereof is used.
The present inventors have studied the problems of the prior art, and have found that in conventional plating solutions, reduction of silver ions progresses in the plating solution to form aggregates containing silver. It has been found that it adheres between the conductive thin wires, grows during the plating process, and causes a short circuit between the conductive thin wires. Therefore, by using a predetermined amount of a polymer having a carboxyl group or a salt thereof, the generation and growth of aggregates containing silver in the plating solution are suppressed, and as a result, the formed conductive fine line has excellent conductivity. It has been found that the occurrence of a short circuit between conductive thin wires (especially between conductive thin wires with an interval of 30 μm or less) can be suppressed while maintaining the

The plating solution of the present invention (hereinafter also simply referred to as "plating solution") contains a silver salt, a polymer having a carboxyl group or a salt thereof, and water, and the content of the polymer having a carboxyl group or a salt thereof is is 5.0% by mass or less with respect to the total mass of the plating solution.
In the following, first, the plating solution will be described in detail, and then the method for manufacturing the conductive substrate will be described in detail.

<Plating solution>
(silver salt)
The plating solution contains silver salt.
The type of silver salt is not particularly limited, and known silver salts can be used. As the silver salt, a water-soluble silver salt is preferred. A water-soluble silver salt means a silver salt that dissolves in water in an amount of 0.1% by mass or more.

Silver salts include inorganic silver salts and organic silver salts, with inorganic silver salts being preferred.
Inorganic silver salts include, for example, silver nitrate, silver fluoride, silver perchlorate, and silver sulfate.

The content of the silver salt in the plating solution is not particularly limited, and at least one of the following effects can be obtained: better conductivity of the conductive fine wires, and further suppression of short circuits between the conductive fine wires. 0.01 to 5.0 mol/L is preferable, and 0.10 to 3.0 mol/L is more preferable in terms of point (hereinafter also simply referred to as "point where the effect of the present invention is more excellent").
Only one kind of silver salt may be used, or two or more kinds thereof may be used in combination.

(Polymer having a carboxyl group or a salt thereof)
The plating solution contains a polymer having a carboxyl group or a salt thereof (hereinafter also simply referred to as "acid group-containing polymer").
A salt of a carboxyl group represents a group represented by the general formula (X).
General formula (X) -COO ^- M ⁺
M ⁺ represents a monovalent cation. Monovalent cations include, for example, alkali metal ions (eg, sodium, potassium, and lithium ions), ammonium ions (eg, NH ₄ ⁺ ), and pyridinium ions.

The acid group-containing polymer is not particularly limited as long as it has a carboxyl group or a salt thereof. Among others, the acid group-containing polymer preferably has a repeating unit having a carboxyl group or a salt thereof.
A repeating unit having a carboxyl group or a salt thereof is preferably a repeating unit represented by general formula (Y) or a repeating unit represented by general formula (Z).

R ^a1 represents a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is preferably 1-5, more preferably 1-3, and even more preferably 1.
L ^a1 represents a single bond or a divalent linking group. As the divalent linking group, for example, a divalent hydrocarbon group (e.g., an alkylene group, an alkenylene group, a divalent aliphatic hydrocarbon group such as an alkynylene group, and a divalent aromatic group such as an arylene group) group hydrocarbon group), divalent heterocyclic group, -O-, -S-, -NH-, -N(Q)-, -CO-, or a group combining these (e.g., -O-2 valent hydrocarbon group -, - (O-divalent hydrocarbon group) _m -O- (m represents an integer of 1 or more), and -divalent hydrocarbon group -O-CO-, etc.) is mentioned. Q represents a hydrogen atom or an alkyl group.
R ^a2 represents a carboxyl group or a salt thereof.

Each R ^b1 independently represents a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is preferably 1-5, more preferably 1-3, and even more preferably 1.
Each L ^b1 independently represents a single bond or a divalent linking group. The definition of the divalent linking group represented by L ^b1 is the same as the definition of the divalent linking group represented by L ^a1 .
Each R ^b2 independently represents a carboxyl group or a salt thereof.

The content of repeating units having a carboxyl group or a salt thereof in the acid group-containing polymer is not particularly limited, but is preferably 50 mol% or more, more preferably 75 mol% or more, based on the total repeating units in the acid group-containing polymer. preferable. Although the upper limit is not particularly limited, 100 mol % can be mentioned.

The acid group-containing polymer may have repeating units other than repeating units having a carboxyl group or a salt thereof.

Although the weight average molecular weight of the acid group-containing polymer is not particularly limited, it is preferably from 2,000 to 1,000,000, more preferably from 2,000 to 500,000, from the viewpoint that the effects of the present invention are more excellent.
In this specification, the weight average molecular weight is defined as a polystyrene equivalent value by GPC (Gel Permeation Chromatography) measurement.
For example, for GPC measurement, HLC-8121GPC (manufactured by Tosoh Corporation) is used, two TSKgel GMH _HR -H(20) HT (manufactured by Tosoh Corporation, 7.8 mm ID × 30 cm) are used as columns, and 1, 2,4-trichlorobenzene is used. The conditions are as follows: sample concentration of 0.02% by mass, flow rate of 1.0 ml/min, sample injection amount of 300 μl, measurement temperature of 160° C., and an IR (infrared) detector.

The content of the acid group-containing polymer in the plating solution is 5.0% by mass or less with respect to the total mass of the plating solution. Among them, 0.01 to 5.0% by mass is preferable, and 0.05 to 5.0% by mass is more preferable, because the effects of the present invention are more excellent.
Only one type of acid group-containing polymer may be used, or two or more types may be used in combination.

The ratio of the silver-equivalent mass of the silver salt to the mass of the acid-group-containing polymer (the silver-equivalent mass of the silver salt/the mass of the acid-group-containing polymer) is not particularly limited, and is often 0.01 to 20. 0.10 to 5.0 is preferable in that the effect is more excellent.
The silver-equivalent mass means the mass of silver produced by reducing all of the silver salt.

(water)
The plating solution contains water.
Although the content of water in the plating solution is not particularly limited, it is preferably 60 to 95% by mass, more preferably 80 to 90% by mass, based on the total mass of the plating solution.

(other ingredients)
The plating solution may contain components other than the above-described silver salt, acid group-containing polymer, and water.
The plating solution may contain a complexing agent. Complexing agents include sulfites, thiosulfates, or organic compounds having imide or amide groups. Complexing agents include, for example, sodium sulfite, potassium sulfite, ammonium sulfite, sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, hydantoin compounds, and imide compounds.
Although the content of the complexing agent in the plating solution is not particularly limited, it is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, based on the total mass of the plating solution.
Complexing agents may be used alone or in combination of two or more.

The plating solution may contain a reducing agent. Examples of reducing agents include ascorbic acid compounds such as ascorbic acid and isoascorbic acid or salts thereof, hydrazine, hydrazine monohydrate, hydrazine sulfate and hydrazine chloride and the like, hydrazines or salts thereof, hydroquinones such as hydroquinone and methylhydroquinone, and the like. derivatives, and pyrogallol or its derivatives such as pyrogallol, pyrogallol monomethyl ether, pyrogallol-4-carboxylic acid, pyrogallol-4,6-dicarboxylic acid and gallic acid.
Although the content of the reducing agent in the plating solution is not particularly limited, it is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, based on the total mass of the plating solution.
Only one reducing agent may be used, or two or more reducing agents may be used in combination.
As will be described later, when the plating solution does not contain a reducing agent, a reducing solution containing a reducing agent may be prepared separately.

The plating solution may contain other additives (eg, pH adjuster, potassium iodide) in addition to the above. Potassium iodide contributes to the improvement of the plating speed.

Although the pH of the plating solution is not particularly limited, it is preferably from 8.0 to 13.0, more preferably from 9.0 to 11.0, from the standpoint that the effects of the present invention are more excellent.
pH is a value measured at 25°C.

<Plating set>
The plating solution may be a plating set consisting of this plating solution and a reducing solution containing a reducing agent. In particular, when the plating solution does not contain a reducing agent, plating can be performed by using the reducing solution.
The types of reducing agents contained in the reducing liquid are as described above.
The content of the reducing agent in the reducing liquid is not particularly limited, but is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, relative to the total mass of the reducing liquid.
Only one reducing agent may be used, or two or more reducing agents may be used in combination.

<Method for manufacturing conductive substrate>
The manufacturing method of the conductive substrate of the present invention has steps 1 and 2 below.
Step 1: a step of forming a fine-line silver-containing layer on a support;
Step 2: A step of plating the fine wire-like silver-containing layer using the above plating solution or the above plating set to form a conductive fine wire.

(Step 1)
Step 1 is a step of forming a fine linear silver-containing layer on a support. A fine wire-shaped silver-containing layer to be plated is formed in this step.

The type of support used in this step is not particularly limited, and includes 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) (melting point: 258°C), polycycloolefin (melting point: 134°C), polycarbonate (melting point: 250°C), acrylic film (melting point: 128°C), and polyethylene resin. Phthalate (melting point: 269°C), polyethylene (melting point: 135°C), polypropylene (melting point: 163°C), polystyrene (melting point: 230°C), polyvinyl chloride (melting point: 180°C), polyvinylidene chloride (melting point: 212°C) ) and triacetyl cellulose (melting point: 290° C.) are preferable, and PET, polycycloolefin and polycarbonate are more preferable.
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 from 0.02 to 0.3 μm, more preferably from 0.03 to 0.2 μm, from the viewpoint of better adhesion of the fine conductive wires to the support.

The width of the fine linear silver-containing layer formed on the support is not particularly limited, and is often 0.1 to 30 μm, preferably 0.5 to 20 μm, more preferably 0.5 to 15 μm, from the viewpoint of thinning. is more preferred.
In addition, the thin line-shaped silver-containing layer may form a predetermined pattern. , rectangles, rhombuses, parallelograms, trapezoids, etc.), (regular) n-sided polygons such as (regular) hexagons, (regular) octagons, etc., circles, ellipses, stars, and geometric figures combining these is preferable, and a mesh shape (mesh pattern) is more preferable.

As shown in FIG. 1, the mesh shape includes a shape including a plurality of openings 12 constituted by intersecting thin wire-like silver-containing layers 10 . Although the length L of one side of the opening 12 is not particularly limited, it 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 even more preferably 80 μm or more.
Although the width of the fine-line silver-containing layer forming the mesh pattern is not particularly limited, it is preferably 0.5 μm or more and less than 4.0 μm from the viewpoint of visible light transmittance.

In FIG. 1, the opening 12 has a diamond shape, but other shapes are possible. For example, polygonal shapes (eg, triangles, squares, hexagons, and random polygons) may be used. In addition, the shape of one side may be curved, or arc-shaped, instead of linear. In the case of an arc shape, for example, two opposing sides may be arcuately convex outward, and the other two opposing sides may be arcuately convex inward. Moreover, the shape of each side may be a wavy line shape in which an outwardly convex circular arc and an inwardly convex circular arc are continuous. Of course, the shape of each side may be a sine curve.

From the viewpoint of visible light transmittance, the open area ratio of the mesh pattern formed from the fine linear silver-containing layer is preferably 85% or more, more preferably 90% or more, and more preferably 95% or more. More preferred. The aperture ratio corresponds to the ratio of the area on the support, excluding the area where the fine-line-shaped silver-containing layer is present, to the entire area.

Also, the plurality of fine-line-shaped silver-containing layers may be arranged in parallel with each other. More specifically, as shown in FIG. 2 , the plurality of fine linear silver-containing layers 10 may be arranged along a direction orthogonal to the direction in which the fine linear silver-containing layers 10 extend. At that time, the extending directions of the plurality of fine-line-shaped silver-containing layers are arranged so as to be parallel to each other. Such a thin wire-shaped silver-containing layer arranged in parallel is used, for example, as a lead wiring arranged in a non-display portion in a touch panel, and the width of this non-display portion, the so-called frame portion, is determined from the viewpoint of design. In recent years, it is often designed to be narrow. In order to save space in wiring arrangement, the line width of the fine line-shaped silver-containing layer is preferably 30 μm or less, more preferably 20 μm or less. Although the lower limit is not particularly limited, it is often 5 μm or more. From the same point of view, the interval between the fine linear silver-containing layers is preferably 30 μm or less, more preferably 20 μm or less. Although the lower limit is not particularly limited, it is often 5 μm or more.

A method for forming a fine-line-shaped silver-containing layer on a support is not particularly limited, and a known method is employed. For example, a method of exposing and developing using a silver halide, and a method of forming a silver layer on the entire surface of the support and then removing a part of the silver layer using a resist pattern to form a fine linear silver-containing layer. A method of forming
Among them, the method of exposing and developing using silver halide is preferable because the effects of the present invention are more excellent.
This method will be described in detail below.

The method of exposing and developing using silver halide preferably includes the following steps.
Step A: Step of forming a silver halide-containing photosensitive layer containing silver halide, gelatin, and a polymer different from gelatin on a support Step B: After exposing the silver halide-containing photosensitive layer, it is developed. Process to form a fine linear silver-containing layer containing metallic silver, gelatin, and a polymer different from gelatin by treatment Process C: Process D to heat-treat the silver-containing layer obtained in Process B : Step of removing gelatin in the silver-containing layer obtained in Step C The procedure of each step will be described in detail below.

(Step 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.
The support used in this step is as described above.

[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 to all halide ions in the silver halide composition is 50% or more. 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.

[Polymers 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 resins, polycarbonate resins, polydiene resins, epoxy resins, silicone resins, cellulose resins, and chitosan resins, or a single component of these resins. Examples thereof include copolymers composed of monomers.
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. L represents a divalent linking group, preferably a group represented by the following general formula (3).
General formula (3): -(CO-X ¹ ) _r -X ² -
In general formula (3), 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 (eg, 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).

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 fine wire is maintained.

[Procedure of step 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.
Below, the form of the composition for forming a photosensitive layer used in this method will be described in detail, and then the procedure of the steps will be described in detail.

[Materials contained in the composition for forming a 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 containing metallic silver, gelatin, and a specific 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-line-shaped silver-containing layer containing metallic silver, gelatin, and a specific polymer is formed.

In addition, as a method of adjusting the width of the silver-containing layer, for example, a method of adjusting the opening width of the mask used at the time of exposure can be mentioned.
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.

(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 a method of contacting the silver-containing layer with warm water is preferable. Examples thereof include a method of immersing the silver-containing layer in warm water and a method of applying warm water on 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, and the like. Among them, hydrogen peroxide water (standard electrode potential: 1.76 V), hypochlorous acid or a salt thereof are preferred, and sodium hypochlorite is more preferred, in terms of productivity and economy.

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.

(Step 2)
Step 2 is a step of plating the thin wire-shaped silver-containing layer obtained in Step 1 with the above plating solution or the above plating set to form a conductive thin wire.
By carrying out this step, plating is deposited on and inside the fine-line-shaped silver-containing layer. In particular, since there is a space formed by removing gelatin in the silver-containing layer obtained by the above steps A to D, the space was filled with a metal (plated metal) by performing this step. A thin conductive line is formed.

The plating solution and plating set used in this step are as described above.

The procedure of the plating treatment is not particularly limited, and when a plating solution is used, any method may be used as long as the silver-containing layer is brought into contact with the plating solution, and examples thereof include 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 30 seconds to 30 minutes from the viewpoints of better conductivity of the conductive thin wire and productivity.

In the case of using a plating set, a plating solution and a reducing solution are sequentially or simultaneously applied to the silver-containing layer, the silver-containing layer is brought into contact with the plating solution and the reducing solution, and plating is performed on and inside the silver-containing layer. is deposited.

(Other processes)
The method for manufacturing a conductive substrate of the present invention may have other steps than the steps 1 and 2 described above.

The method for manufacturing a conductive substrate according to the present invention may include, after step 2, step 3 of smoothing the conductive thin wires obtained in step 2.
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.

The method for manufacturing a conductive substrate of the present invention may further include a step 4 of heat-treating the conductive fine wires obtained in the step 3 after the step 3. 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.

The method for producing a conductive substrate of the present invention may have, before step A, step E 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 the improvement of the adhesion between the fine conductive wires 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.

The method for producing a conductive substrate of the present invention has, after step A and before step B, step F of forming a protective layer containing gelatin and a specific polymer on the silver halide-containing photosensitive layer. 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.

<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. 3 shows a cross-sectional view of a first embodiment of the conductive substrate of the present invention.
Conductive substrate 20 includes support 14 and conductive wires 16 disposed on support 14 . Although two conductive thin wires 16 are shown in FIG. 1, the number is not particularly limited.

The line width of the conductive thin line is not particularly limited, and is often 0.1 to 30 μm.
The conductive fine lines may form a predetermined pattern. The pattern formed by the fine conductive wires includes the pattern formed by the silver-containing layer of fine wires described above, and is preferably in the form of a mesh (mesh pattern).
The mesh shape is the form shown in FIG. 1 described above.
The preferable range of the length of one side of the opening of the mesh pattern formed by the conductive fine lines is the same as the preferable range of the length of one side of the opening of the mesh pattern formed by the fine line-shaped silver-containing layer described above. be.
The preferred range of the aperture ratio of the mesh pattern formed of the conductive thin wires is the same as the preferred range of the aperture ratio of the mesh pattern formed of the fine wire-like silver-containing layer described above.
Also, the line width of the conductive fine lines forming the mesh pattern is not particularly limited, but from the viewpoint of visible light transmittance, it is preferably 0.5 μm or more and less than 4.0 μm.

Also, the plurality of conductive thin wires may be arranged parallel to each other. More specifically, as in the fine-line silver-containing layer shown in FIG. 2, the plurality of conductive fine wires may be arranged along a direction perpendicular to the direction in which the conductive fine wires extend. At that time, the extending directions of the plurality of conductive thin wires are arranged so as to be parallel to each other. Such parallelly arranged conductive thin wires are used, for example, as lead wires arranged in the non-display portion of a touch panel, and the width of this non-display portion, the so-called frame portion, has been designed to be narrower in recent years from the viewpoint of design. It is often done. In order to save space in wiring arrangement, the line width of the conductive thin line is preferably 30 μm or less, more preferably 20 μm or less. Although the lower limit is not particularly limited, it is often 5 μm or more. From the same point of view, the distance between the conductive thin wires is preferably 30 μm or less, more preferably 20 μm or less. Although the lower limit is not particularly limited, it is often 5 μm or more.

<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.

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.

< Reference 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 trace amounts of hardening agents were added to form the composition. got The pH of the composition was then adjusted to 5.6 using citric acid.
To the above composition, a polymer represented by the following (P-1) (hereinafter also referred to as "polymer 1". Numerical values in the formula ("8.6", "58.9", "2", "25.4" and "5.1") represent the molar ratio of each repeating unit) and dialkylphenyl PEO (PEO is an abbreviation for polyethylene oxide). (The ratio of the mass of the dispersant to the mass of the polymer 1 (mass of the dispersant/mass of the polymer 1, unit: g/g) was 0.02, and the solid content was 22% by mass. ) was added so that 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) was 0.25/1, A polymer latex-containing composition was obtained. 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 (“Long roll 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 E-1, Step A-1, Step F-1)
Next, on the undercoat layer, a protective layer is formed by mixing a silver halide-free layer-forming composition comprising a mixture of the above polymer latex and gelatin, the above composition for forming a photosensitive layer, a 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 B-1)
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 a photomask, a mask for forming a mesh pattern as shown in FIG. 1 is used. The line width of the unit square lattice forming the lattice is 1.2 μm, and the length L of one side of the lattice (opening) is 600 μm. I made it to be

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 Fujifilm Corporation), and then heated at 25°C. of pure water and then dried to obtain a sample A having a silver-containing layer containing metallic silver formed in a mesh pattern. 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 C-1)
Sample A obtained in step B-1 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 D-1)
Sample A obtained in step C-1 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 2-1)
Sample A obtained in step D-1 was immersed in plating solution A (30° C.) having the following composition for 3 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 (1200 g in total) was as follows. The pH of the plating solution A was 10, 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)
・AgNO ₃ 1.0 mol/l
・Sodium sulfite 72g
・ Sodium thiosulfate pentahydrate 42g
・ Potassium iodide 0.004 g
・ Sodium polyacrylate 12g
・Methylhydroquinone 3.7g
・Potassium carbonate prescribed amount ・Remainder of water

(Step 3-1)
Sample A obtained in step 2-1 was subjected to calendering at a pressure of 30 kN using a calendering device with a combination of metal rolls and resin rolls. Calendering was performed at room temperature.

(Step 4-1)
The sample A obtained in step 3-1 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.

In sample A obtained in step 4-1, the conductive fine wires formed a mesh pattern. The line width of the conductive thin line was 1.5 μm.

In addition, 100 samples B each having a comb-like pattern region shown in FIG. . In FIG. 4, the pattern width W was 10 μm, the pattern interval I was 10 μm, and the pattern length L was 30 cm.

< Example 1 2, Comparative Examples 1 to 4 , Reference Examples 2 to 11, 13 >
Samples A and B were prepared in the same manner as in Reference Example 1, except that the silver salt concentration in the plating solution, the type, concentration and molecular weight of the acid group-containing polymer, and the silver/polymer ratio were changed as shown in Table 1. was made.

< Reference Example 13>
Evaluation was carried out in the same manner as in Reference Example 1, except that the pattern interval I in the comb-tooth pattern region shown in FIG.

<Evaluation>
(Conductivity)
The line resistance value of the conductive mesh pattern area of the obtained sample A 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 a source meter (KEITHLEY source meter, 2400 type general-purpose source meter) was used for the outermost probes A and D, and the interval was 250 μm. 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.
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.

(short rate)
In sample B in which the comb-shaped pattern region is formed, the resistance at both ends of the comb-shaped pattern region was measured using a PICOTEST digital multimeter M3500A manufactured by Toyo Keisokuki Co., Ltd. If no short-circuit occurs, both ends of the comb-shaped pattern region are not conductive, so the resistance value indicates overload (infinite). be The number of short circuits in 100 samples B was counted by the above method, and the short ratio was obtained. The results are summarized in Table 1.
In addition, the following short rate was calculated|required from the following formulas.
Short-circuit rate (%)={(number of samples B with short-circuit)/100}×1005: Short-circuit rate is 0%.
4: The short rate is 1%.
3: The short rate is 2 to 3%.
2: The short rate is 4 to 10%.
1: The short rate is 11% or more.

In Table 1, the "concentration" column in the "acid group-containing polymer" column represents mass % of the acid group-containing polymer with respect to the total mass of the plating solution.
The "molecular weight" column represents the weight average molecular weight of the acid group-containing polymer.
"Silver/polymer ratio" represents the ratio of the weight of the silver salt converted to silver to the weight of the acid group-containing polymer.

As shown in Table 1, it was confirmed that the use of the plating solution of the present invention produced the desired effects.
From the comparison of Reference Examples 1 to 4, it was confirmed that when the weight average molecular weight of the acid group-containing polymer is 2,000 to 500,000, the effect is more excellent.
Moreover, it was confirmed from the comparison of Reference Examples 5 to 9 that the effect is more excellent when the silver/polymer ratio is 0.10 to 5.0.

REFERENCE SIGNS LIST 10 fine wire-like silver-containing layer 12 opening 14 support 16 conductive fine wire 20 conductive substrate

Claims (7)

A plating solution containing a silver salt, a polymer having a carboxyl group or a salt thereof, and water,
The content of the polymer having a carboxyl group or a salt thereof is 5.0% by mass or less with respect to the total mass of the plating solution,
The polymer having a carboxyl group or a salt thereof has a weight average molecular weight of 2000 to 6000,
The plating solution, wherein the polymer having a carboxyl group or a salt thereof is sodium acrylic acid/maleic acid copolymer . 2. The plating solution according to claim 1 , wherein the ratio of the mass of said silver salt in terms of silver to the mass of said polymer having a carboxyl group or a salt thereof is 0.10 to 5.0. 3. The plating solution according to claim 1, further comprising a reducing agent. A plating set comprising the plating solution according to claim 1 or 2 and a reducing solution containing a reducing agent. a step of forming a fine-line-shaped silver-containing layer on a support;
The thin wire-shaped silver-containing layer is subjected to plating using the plating solution according to any one of claims 1 to 3 or the plating set according to claim 4 to form a conductive thin wire. and forming a conductive substrate. A plurality of the conductive thin wires are arranged parallel to each other,
6. The method of manufacturing a conductive substrate according to claim 5 , wherein there is a region in which the distance between adjacent conductive fine lines is 30 [mu]m or less. A mesh pattern is formed by the conductive thin wires,
6. The method for manufacturing a conductive substrate according to claim 5 , wherein the line width of said conductive thin line is 0.5 [mu]m or more and less than 4.0 [mu]m.