JP2015067848A - Metal film forming method on ito film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode material on a surface of an ITO(oxidation indium tin) film, which is thin and uniform with high conduction.SOLUTION: A metal film is formed on an ITO film by a method including a process (A) for forming organic film consisting of a polyfunctional organic chemical compound (preferably arginine) which is selected from (a) a chemical compound including an amino group and a carboxyl group, (b) a chemical compound including two or more amino groups, (c) a chemical compound including two or more carboxyl groups, and (d) a chemical compound including an amino group and hydroxyl group, on the ITO film; a process (B) for attracting metal ion of a catalysis on the organic film formed in the process (A); and a process (C) for forming the metal film by performing electroless plating by activating the attracted metal ion in the process (B).

Description

  The present invention relates to a method for forming a metal film on an ITO film. Specifically, the present invention relates to a method for forming a thin, uniform and excellent conductive metal film on an ITO film.

ITO (Indium Tin Oxide), which is a transparent electrode material, has a visible light transmittance of about 90%, so it is widely used for electrodes and illumination for FPD (flat panel displays) such as liquid crystal panels and organic EL displays. Has been.
However, ITO has a drawback of low conductivity. Therefore, a technique for improving the conductivity by forming a metal film on the surface of the ITO film has been studied.

  As a method for forming a metal film on the surface of the ITO film, a dry process such as a vapor deposition method or a sputtering method can be considered (Patent Document 1; Japanese Patent Application Laid-Open No. 2013-120411, etc.). Not suitable for processing.

  The method of forming a metal film by plating can be continuously manufactured with simple equipment. For example, a method of directly forming a metal film on an ITO film by electroplating has been proposed (Patent Document 2; JP 2012-248285A). However, since the ITO film has low conductivity, it is difficult to form a uniform metal film. Moreover, it has the fault that it cannot process if an ITO film | membrane is discontinuous. Furthermore, in the case of electroless plating, it is necessary to apply a catalyst.

  Therefore, a method has been proposed in which a resin containing a catalyst or the like is applied onto the ITO film and electroless plating is performed (Patent Document 3; Japanese Patent Application Laid-Open No. 2009-164041). However, in this method, since the ITO film and the metal film are interposed via the resin layer, it is difficult to ensure conduction between the ITO film and the metal film. Moreover, although the method described in Patent Document 3 contains metal fine particles in the resin, it is insufficient to ensure conduction. Furthermore, since the metal film portion is raised by the thickness of the resin, there is a disadvantage that the thickness of the obtained electrode material increases.

  Thus, in order to improve the electrical conductivity of the ITO film, it is desired to develop a method for forming a thin, uniform and excellent conductive metal film on the surface of the ITO film.

JP2013-120411A JP2012-248285A JP2009-164041

  The problem to be solved by the present invention is to provide a method for forming a thin, uniform and excellent conductive metal film on the surface of an ITO film.

  As a result of intensive studies, the inventors of the present invention formed an organic film of a specific substance on the ITO film, adsorbed metal ions serving as a catalyst thereto, activated the adsorbed metal ions, and performed electroless plating. The present inventors have found that a metal film having a thin thickness, a uniform thickness and excellent conductivity can be formed, and the present invention has been achieved.

  That is, the present invention relates to a method for forming a metal film on an ITO film and a conductive film described below.

(1) A method for forming a metal film on an ITO film, comprising the following steps (A) to (C).
(A) The process of forming the organic membrane | film | coat which consists of a polyfunctional organic compound selected from the group which consists of following (a)-(d) on an ITO film | membrane (a) Compound which has an amino group and a carboxyl group (b) Compound having two or more amino groups (c) Compound having two or more carboxyl groups (d) Compound having amino groups and hydroxyl groups (B) Metal ions serving as a catalyst on the organic film formed in the step (A) Step of adsorbing (C) Step of activating the metal ions adsorbed in the step (B) and performing electroless plating to form a metal film

(2) The method for forming a metal film according to (1), wherein the metal film has a thickness of 20 to 1,000 nm.

(3) The step of forming the organic film includes a step of applying an aqueous solution having a polyfunctional organic compound concentration of 0.001 to 0.1M to the surface of the ITO film. Of forming a metal film.
(4) The method for forming a metal film according to any one of (1) to (3), wherein the metal ions are palladium ions.

(5) An electrode material having a base material including an ITO film and a metal film formed on the ITO film, and comprising the following (a) to (d) between the ITO film and the metal film: An electrode material comprising an organic film made of a polyfunctional organic compound selected from the group.
(A) A compound having an amino group and a carboxyl group (b) A compound having two or more amino groups (c) A compound having two or more carboxyl groups (d) A compound having an amino group and a hydroxyl group

(6) The electrode material according to (5), wherein the metal film has a thickness of 20 to 1,000 nm.
(7) The manufacturing method of the electrode material as described in (5) including the formation method of the metal film as described in (1).

  According to the present invention, since there is only a very thin organic film and a metal serving as a catalyst between the ITO film and the metal film, an electrode material having a thin and uniform thickness and good conductivity can be obtained.

The metal film forming method of the present invention includes the steps (A) to (C).
1. Step (A): Organic Film Formation Step In the step (A) in the present invention, an organic film made of a polyfunctional organic compound selected from the group consisting of the following (a) to (d) is formed on the ITO film.
(A) A compound having an amino group and a carboxyl group (b) A compound having two or more amino groups (c) A compound having two or more carboxyl groups (d) A compound having an amino group and a hydroxyl group

(1) ITO film The thickness of the ITO (Indium Tin Oxide) film is not particularly limited. The thickness of the ITO film is appropriately selected according to the application, and the method of the present invention for forming a metal film on the surface can be applied. The ITO film may be a single film, or may be an ITO film formed on a base substrate.

  If desired, the ITO film can be degreased in advance for the purpose of keeping its surface clear. As the degreasing treatment, a known method such as washing with an alcohol or the like or treatment with a surfactant can be employed.

(2) Polyfunctional Organic Compound As the polyfunctional organic compound used in the present invention, (a) a compound having an amino group and a carboxyl group (hereinafter “compound (a)”), (b) two or more amino groups. A compound having an amino group and a hydroxyl group (hereinafter referred to as “compound (b)”), (c) a compound having two or more carboxyl groups (hereinafter “compound (c)”), and (d) an amino group and a hydroxyl group. “Compound (d)”). Specific examples include the following compound groups.

(A) Compound having amino group and carboxyl group: Compound (a)
As the compound (a) used in the present invention, specifically, a compound having one amino group and one carboxyl group (neutral amino acid), a compound having one amino group and two or more carboxyl groups (acidic amino acid) ) And the like (basic amino acids) having two or more amino groups and one carboxyl group. The compound (a) may contain a functional group other than the amino group and the carboxyl group. The compound which overlaps with a compound (b), a compound (c), and a compound (d) may be included.

  More specifically, amino acids such as glutamic acid (acidic amino acid); glycine, cysteine (neutral amino acid); lysine, histidine, arginine (basic amino acid) and the like can be mentioned.

(B) Compound having two or more amino groups:
Specific examples of the compound having two or more amino groups used in the present invention include compounds having two amino groups. The compound (b) may contain a functional group other than the amino group, and examples of the functional group other than the amino group include a carboxyl group and a hydroxyl group. The compound which overlaps with a compound (a), a compound (c), and a compound (d) may be included.

  More specifically, ethylenediamine or guanidine-based compounds are exemplified. Examples of guanidine compounds include arginine, which is the basic amino acid, and guanidine hydrochloride and aminoguanidine hydrochloride.

(C) Compound having two or more carboxyl groups:
Specific examples of the compound having two or more carboxyl groups used in the present invention include compounds having two carboxyl groups.
The compound (c) may contain a functional group other than the carboxyl group, and examples of the functional group other than the carboxyl group include an amino group. The compound which overlaps with a compound (a), a compound (b), and a compound (d) may be included. More specifically, succinic acid, oxalic acid, malonic acid and the like can be mentioned.

(D) Compound having amino group and hydroxyl group:
Specific examples of the compound having an amino group and a hydroxyl group used in the present invention include a compound having one amino group and one hydroxyl group.
In the compound (d), a functional group other than the amino group and the hydroxyl group may be included, and examples of the functional group other than the amino group and the hydroxyl group include a carboxyl group. The compound which overlaps with a compound (a), a compound (b), and a compound (c) may be included. More specifically, 2-aminoethanol, 1-amino-2-propanol and the like can be mentioned.

  In addition, as a polyfunctional organic compound used for this invention, it is preferable not to have polymerizable double bonds, such as an acryl group.

  The molecular weight of the polyfunctional organic compound is not particularly limited, but is preferably about 45 to 300. When the molecular weight of the polyfunctional organic compound is within this range, it is easy to be dissolved in a solvent and easy to handle, and there is an advantage that a decrease in conductivity due to the organic film can be suppressed.

(3) Formation method of organic film As a method of forming an organic film composed of a polyfunctional organic compound, the polyfunctional organic compound is dissolved in an aqueous solvent or an organic solvent, and then a solution containing the polyfunctional organic compound is applied. A method is mentioned. Examples of the coating method include known methods such as a dipping method (dip method) or a coating method. Specific examples of the coating method include a bar coater, a micro gravure coater, and a dip coater.

  Furthermore, the organic film can be formed in a specific pattern using a printing method such as ink jet printing, screen printing, intaglio printing, or relief printing. According to this, a metal film can be selectively formed only on the patterned organic film portion. As another pattern forming method, a method of applying a solution containing a polyfunctional organic compound after forming a reverse pattern by masking and then removing the masking can be employed.

Specific examples of the solvent include water and alcohol. Preferably it is water.
The concentration of the polyfunctional organic compound in the solution containing the polyfunctional organic compound is not particularly limited, but is preferably 0.001 to 0.1M, more preferably 0.01 to 0.05M. When the concentration of the polyfunctional organic compound in the solution containing the polyfunctional organic compound is less than 0.001M, the organic film is not sufficiently formed, and as a result, the metal film is not sufficiently formed. Even if the concentration of the polyfunctional organic compound exceeds 0.1M, there is no great difference in the formation of the organic film, and the excess polyfunctional organic compound is wasted.

  When the immersion method is used to form the organic film, the temperature in the immersion bath (solution temperature at the time of immersion) made of a solution containing a polyfunctional organic compound is preferably 30 to 50 ° C., and the immersion time is preferably 1 to 10 minutes. It is. If the temperature is within this range, the organic film is suitably formed.

  In the dipping method, it is usually dried after dipping. A preferable drying temperature is 80 to 100 ° C., and a drying time is 5 to 10 minutes.

  The film thickness of the organic film formed by the above method is 0.5 to 100 nm. If the film thickness is less than 0.5 nm, it is difficult to form a uniform film, and the metal film after plating may be uneven. If the film thickness exceeds 100 nm, the conduction between the metal film and the ITO film may be poor.

2. Step (B): Metal Ion Adsorption Step In the step (B) in the present invention, metal ions serving as a catalyst are adsorbed on the surface of the organic film formed in the step (A).

(1) Metal ions The metal ions used in the step (B) serve as a catalyst for electroless plating in the subsequent step (C). Specific examples of the metal ion include one or more selected from palladium ion, copper ion, and nickel ion.

The metal ions are used for adsorption treatment after making a metal ion-containing solution using a solvent. The solvent used in the metal ion-containing solution is not particularly limited, but is preferably water.
The pH of the metal ion-containing solution is preferably 2-6. If the pH of the metal ion-containing solution is less than 2, the metal ion adsorption may be poor. When pH exceeds 6, there exists a possibility that stability of a metal ion containing solution may fall.

  In order to maintain the pH of the metal ion-containing solution in an appropriate range, a pH adjuster can be appropriately used. As the pH adjuster, known acids, alkalis and the like can be used. Further, a pH buffering agent can be used. As the pH buffering agent, borax, sodium phosphate, potassium phosphate, sodium carbonate, potassium carbonate and the like can be used, and borax is particularly preferable. The blending amount of the pH buffer is preferably 0.2 to 3 g / L, more preferably 0.5 to 2 g / L.

  The metal ion concentration in the metal ion-containing solution is not particularly limited, but is preferably 0.01 mM to 50 mM, more preferably 0.05 mM to 20 mM, still more preferably 0.05 mM to 10 mM, and particularly preferably 0. 0.08 mM to 0.9 mM. If the metal ion concentration is less than 0.01 mM, the deposition property of the metal film may be lowered. If the metal ion concentration exceeds 50 mM, the adhesion property of the metal film may be lowered, and the cost increases. There is a case.

(2) Adsorption method Examples of a method for adsorbing metal ions on the surface of the organic film include a method in which an ITO film having the organic film formed on the surface is brought into contact with a metal ion-containing solution.
Examples of the contact method include a method of immersing an ITO film having an organic film formed on the surface thereof in a metal ion-containing solution, and a method of spraying the metal ion-containing solution in a spray form on the ITO film.

  The reaction temperature when the ITO film having the organic film formed on the surface is brought into contact with the metal ion-containing solution is 10 ° C to 80 ° C, preferably 30 ° C to 50 ° C. The contact time of the metal ion-containing solution is preferably 10 seconds to 800 seconds, more preferably 60 seconds to 500 seconds.

After the contact with the metal ion-containing solution, the ITO film is washed with water to remove non-specifically attached metal ions. At this time, if ultrasonic cleaning or the like is performed, cleaning can be performed efficiently.
The metal ions adsorbed on the surface of the organic coating are considered to coordinate with the functional group to form a metal salt.

3. Step (C): Electroless plating step In the step (C) in the present invention, the electroless plating is performed by activating the metal ions adsorbed on the surface of the organic film in the step (B).

(1) Activation treatment As a method for activating the metal ions adsorbed on the surface of the organic film, specifically, the metal ions can be reduced.
In the step (C), the ITO film is brought into contact with a treatment liquid containing a reducing agent, and the metal ions adsorbed on the surface of the organic film in the step (B) are reduced. Here, examples of the reducing agent used in the treatment liquid containing the reducing agent include dimethylamine borane, sodium hypophosphite, hydrazine, methanol, diethylmethylamine, and ascorbic acid. Of these, dimethylamine borane (DMAB) is particularly preferred because it can be used in an easily handled acidic region.

In addition, the concentration of the reducing agent in the treatment liquid containing the reducing agent is preferably 1 mM to 100 mM, more preferably 10 mM to 30 mM. When the reducing agent concentration is within this range, there is an advantage that the deposition property of the plating becomes good.
Although the solvent used for the processing liquid containing the reducing agent of the present invention is not particularly limited, it is preferable to use water. Further, an acidic treatment liquid is generally used as the treatment liquid, but an alkaline treatment liquid may be used depending on the selection of the reducing agent.

  The time for which the ITO film is brought into contact with the treatment liquid containing a reducing agent is 60 seconds to 600 seconds, preferably 180 seconds to 300 seconds. The contact temperature is 10 ° C to 80 ° C, preferably 30 ° C to 50 ° C. After making it contact with the processing liquid containing a reducing agent, the ITO film is washed with water to remove the non-specifically attached reducing agent solution.

(2) Electroless plating (i) Electroless plating metal As the electroless plating metal, at least one metal selected from the group consisting of copper, nickel, tin, and silver or an alloy thereof (for example, copper and Tin alloy, etc.), and copper and nickel are particularly preferred. This metal plating process imparts high conductivity to the ITO film surface.

(Ii) Electroless plating treatment In the present invention, after performing the activation treatment such as the reduction treatment described above, the electroless plating treatment with a desired metal is performed to form a metal layer. An existing plating bath can be used for electroless plating, and the above-described ITO film may be immersed in this plating bath. The plating reaction time and temperature can be appropriately adjusted according to the plating film thickness.

The film thickness of the electroless plating film in the present invention is 20 to 1,000 nm, preferably 50 nm to 500 nm. When the film thickness is within this range, there is an advantage that sufficient conductivity is exhibited and the thickness of the electrode material can be reduced. Further, when a patterned metal film is formed, the level difference between the part with the metal film and the part without the metal film can be reduced.
After forming the electroless nickel plating film, the resin base material is washed with water to remove the plating solution adhering non-specifically.

4). Electrode Material The electrode material of the present invention has a base material including an ITO film and a metal film formed on the ITO film, and the compounds (a) to (d) between the ITO film and the metal film. And an organic film made of a polyfunctional organic compound selected from the group consisting of:

(1) Base Material The base material including the ITO film of the present invention may be used as a base material with a single ITO film, but transparent conductive material is used on the surface of another base base material, for example, a generally used insulating base material. You may use what formed the ITO film | membrane as a film | membrane. As a method for forming the ITO film on the base substrate, a known vacuum film forming method such as a sputtering method or a laser ablation method can be used.

  Base substrates include epoxy resin substrates, polyimide substrates, glass substrates, PET substrates, PEN substrates, or cellulose triacetate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, polytetrafluoroethylene, cyclohexane Substrates formed from resins such as olefin polymer, polyphenylene ether, polyphenylene oxide, liquid crystal polymer, benzocyclobutene resin, polyethersulfone, polyetherimide, polyarylate, aramid resin, phenolic resin, bismaleimide triazine resin, cyanate resin Can be used.

As the base substrate, generally, a flat substrate (various substrates) is used, but the substrate is not necessarily limited to a flat substrate, and a substrate having an arbitrary shape such as a cylindrical shape may be used. it can.
As the conductive substrate in the present invention, among the above-described substrates, an epoxy resin substrate, a polyimide substrate, a glass substrate, a PET substrate formed by forming an ITO film on the insulating substrate surface, Insulating base materials selected from PEN base materials and the like can be preferably used.

(2) Metal film The metal film in the electrode material of the present invention includes at least one metal selected from the group consisting of copper, nickel, tin, and silver, or an alloy thereof (for example, an alloy of copper and tin). It is done. The thickness of the metal film is about 20 to 1,000 nm. When the thickness of the metal film is within this range, there is an advantage that sufficient conductivity is exhibited and the thickness of the electrode material can be reduced.

(3) Organic film The organic film in the electrode material of the present invention is composed of a polyfunctional organic compound selected from the group consisting of the compounds (a) to (d) described above.

(4) Electrode Material The electrode material of the present invention can be produced by a method including the above-described method for forming a metal film of the present invention. That is, using a base material in which an ITO film is formed on a base base material, an organic film made of a polyfunctional organic compound selected from the group consisting of the above (a) to (d) is formed on the ITO film. Then, metal ions that serve as a catalyst are adsorbed on the organic film, and then the adsorbed metal ions are activated to perform electroless plating to form a metal film. The electrode material manufactured using this method has a thin and uniform thickness and good conduction.

5. Applications The electrode material of the present invention can be suitably used for liquid crystal displays, organic EL displays, solar cells, organic EL lighting, light control glass, and the like.

  Examples The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the evaluation method of each physical property in the following examples is as follows.

(1) Precipitation The state of the metal film in the sample after completion of the electroless plating treatment was visually observed to evaluate the precipitation. Of the area of the treated surface, the formation of the metal film in a range exceeding 95% was evaluated as “◯”, 50 to 95% as “Δ”, and the case where it was less than 50% as “X”.

(2) Back surface deposition property The state of the metal film was visually observed on the back surface where the organic film was not formed, and the back surface deposition property was evaluated. The case where the formation of the metal film was confirmed even a little was marked with “X”, and the case where the formation of the metal film was not confirmed was marked with “◯”.

[Example 1]
<Base material>
A glass with a FLAT ITO film (product number 0031, ITO film thickness of 155 nm, glass thickness of 0.7 mm) manufactured by Geomatec Co., Ltd. was used as a substrate for a metal film formation test. The substrate was washed and dried with acetone and then distilled water, and then treated (degreased) with a 500 mL / L aqueous solution of Melcleaner SC-7001 (Meltex Co., Ltd.) at 40 ° C. for about 5 minutes. After the degreasing treatment, it was washed with pure water at 20 ° C. for 1 minute.

<Process (A)>
Arginine was dissolved in water to prepare an aqueous solution containing a polyfunctional organic compound having an arginine concentration of 0.01M. The said board | substrate was immersed for 5 minutes at 40 degreeC in the immersion bath of polyfunctional organic compound containing aqueous solution. Next, the substrate was lifted from the immersion bath and dried at 100 ° C. for 10 minutes. As a result, an organic film was formed on the ITO film of the substrate.

<Process (B)>
The substrate on which the organic film was formed was immersed in a palladium chloride aqueous solution (pH = 4, adjusted with diluted caustic) having the following composition for 5 minutes at 40 ° C. to form a palladium salt on the surface of the ITO film. Thereafter, the substrate was taken out and washed with water to remove non-specifically deposited palladium chloride.

(Composition of palladium chloride aqueous solution)
Palladium chloride; 0.15 g / L
NaCl; 1 g / L
Concentrated hydrochloric acid; 1.353 mL / L

<Process (C)>
The substrate was immersed for 5 minutes at 40 ° C. in an acidic treatment solution containing a reducing agent (0.32 M dimethylamine borane diluted 16-fold with 0.1 N citrate buffer; each composition is as follows) on the substrate. The palladium salt of was reduced. Next, the substrate was taken out from the acidic treatment liquid containing the reducing agent and washed with water to remove the non-specifically attached reducing agent.

(Composition of 0.1N citrate buffer)
Citric acid; 1.38 g / L
Citric acid 3Na; 12.58 g / L
(Composition of 0.32M dimethylamine borane)
Dimethylamine borane; 19.84 g / L

  Subsequently, the substrate was immersed in an electroless nickel plating bath having the following composition at 50 ° C. for 30 seconds to form a nickel film (film thickness: 150 nm). Thereafter, the substrate was washed with water to remove the nickel plating solution. Through the above process, an electrode material in which a metal film having a metal (nickel) film thickness of 150 nm was formed on the ITO film was obtained.

(Composition of electroless nickel plating bath)
Nickel sulfate hexahydrate; 18 g / L
Phosphine sodium monohydrate; 15 g / L
Trisodium citrate dihydrate; 20 g / L
Ammonium chloride; 10 g / L
25% aqueous ammonia; 10 mL / L

[Example 2]
A metal film was formed on the ITO film in the same manner as in Example 1 except that the arginine concentration in the polyfunctional organic compound-containing aqueous solution was changed to 0.02M.

[Example 3]
A metal film was formed on the ITO film in the same manner as in Example 1 except that the arginine concentration of the polyfunctional organic compound-containing aqueous solution was changed to 0.04M.
[Example 4]
A metal film was formed on the ITO film in the same manner as in Example 1 except that the arginine concentration of the polyfunctional organic compound-containing aqueous solution was changed to 0.08M.

[Example 5]
The same procedure as in Example 4 was performed except that arginine was replaced with glutamic acid.
[Example 6]
The same procedure as in Example 4 was performed except that arginine was replaced with glycine.

[Example 7]
The same procedure as in Example 4 was performed except that arginine was replaced with cysteine.
[Example 8]
The same procedure as in Example 4 was performed except that arginine was replaced by lysine.

[Example 9]
The same procedure as in Example 4 was performed except that arginine was replaced with histidine.
[Example 10]
The same procedure as in Example 4 was performed except that arginine was replaced with ethylenediamine.

[Example 11]
The same procedure as in Example 4 was performed except that arginine was replaced with 2-aminoethanol.
[Example 12]
The same procedure as in Example 4 was performed except that arginine was replaced by succinic acid.

[Example 13]
The same procedure as in Example 4 was conducted except that arginine was replaced by guanidine hydrochloride.
[Example 14]
The same procedure as in Example 4 was conducted except that arginine was replaced with aminoguanidine hydrochloride.

[Comparative Example 1]
The same procedure as in Example 1 was performed except that the step (A) was not performed, that is, the organic film was not formed.

  As is apparent from the results of the above examples, the electrode material obtained by the method including the step of forming an organic film composed of the polyfunctional organic compound of the present invention has good metal deposition on the surface, no back surface deposition, and no metal It can be seen that the film is uniformly formed in a desired state at a desired location. This indicates that the specific polyfunctional organic compound of the present invention selectively forms an organic film only on the front ITO film without forming an organic film on the glass substrate on the back surface. ing. Furthermore, although it is considered that the organic film formed on the ITO film uniformly adsorbs catalytic metal ions in a good state, it is not always clear.

According to the present invention, since there is only a very thin organic film and a metal serving as a catalyst between the ITO film and the metal film, an electrode material having a thin and uniform thickness and good conductivity can be obtained.

Claims (7)

A method for forming a metal film on an ITO film, comprising the following steps (A) to (C).
(A) The process of forming the organic membrane | film | coat which consists of a polyfunctional organic compound selected from the group which consists of following (a)-(d) on an ITO film | membrane (a) Compound which has an amino group and a carboxyl group (b) Compound having two or more amino groups (c) Compound having two or more carboxyl groups (d) Compound having amino groups and hydroxyl groups (B) Metal ions serving as a catalyst on the organic film formed in the step (A) Step of adsorbing (C) Step of activating the metal ions adsorbed in the step (B) and performing electroless plating to form a metal film   The method for forming a metal film according to claim 1, wherein the metal film has a thickness of 20 to 1,000 nm.   The method for forming a metal film according to claim 1, wherein the step of forming the organic film includes a step of applying an aqueous solution having a concentration of a polyfunctional organic compound of 0.001 to 0.1 M to the surface of the ITO film. .   The method for forming a metal film according to claim 1, wherein the metal ions are palladium ions. An electrode material having a base material including an ITO film and a metal film formed on the ITO film, and selected from the group consisting of the following (a) to (d) between the ITO film and the metal film An electrode material comprising an organic film made of a polyfunctional organic compound.
(A) A compound having an amino group and a carboxyl group (b) A compound having two or more amino groups (c) A compound having two or more carboxyl groups (d) A compound having an amino group and a hydroxyl group   The electrode material according to claim 5, wherein the metal film has a thickness of 20 to 1,000 nm. The manufacturing method of the electrode material of Claim 5 including the formation method of the metal membrane | film | coat of Claim 1.