JP2010001511A - Method of manufacturing plated product, and plated product manufactured thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a uniformly plated product having a metal plating film with excellent adhesiveness to a base material, and having no exposed portions (irregularities) on a surface of the film. <P>SOLUTION: A method of manufacturing a plated product comprises: (A) a step of forming a coating film layer including reducing polymer particles and binder on a base material; (B) a step of adsorbing catalyst metal on the coating film layer; (C) a step of reducing the adsorbed catalyst metal; and (D) a step of executing the electroless plating by immersing the base material subjected to the reduction in a plating bath. Conductive polymer particles which are reduced through the de-doping treatment are used as the reducing polymer particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has a metal plating film having excellent adhesion to a substrate using an electroless plating method, and there is no exposed portion (unevenness) on the surface of the film. The present invention relates to a plated product to be manufactured.

  Several electroless plating methods for producing an electric circuit by forming a conductive polymer layer on a substrate and plating the conductive polymer layer have been proposed.

Japanese Patent No. 3208735 (Patent Document 1) discloses that a metallized substance is coated with polyaniline, polyaniline is activated by reduction, and the coated substance is treated with a metal ion-containing solution. Disclosed is a method for producing a metallized material, characterized in that the metal is attached to the material by non-electrochemical methods by contacting.
As a concrete example of the above process,
1) A polyaniline-containing polyamide-based mixture (Omecon 9000018/34) is coated on a polyamide film using a doctor blade having a layer thickness of 100 μm.
2) Soaked in 1N sodium hydroxide solution containing 13 g / L hydrazinium sulfate and kept under nitrogen atmosphere at room temperature for 24 hours for reduction;
3) It is transferred to a solution of 0.1N copper tosylate / 0.01N dodecylbenzenesulfonic acid (pH 4) and left in a nitrogen atmosphere for 5 hours for copper adhesion.
A method for obtaining a bronze film is disclosed.

JP 2007-270180 A (Patent Document 1) is a method of manufacturing a plated film in which a patterned metal film is formed on a base film,
1) A monomer of pyrrole and / or a pyrrole derivative is added to an O / W emulsion obtained by mixing and stirring an organic solvent, water, an anionic surfactant and a nonionic surfactant, and the monomer. A step of obtaining fine particles having an electrical conductivity dispersed in an organic solvent of less than 0.01 S / cm by oxidative polymerization of
2) A step of printing a paint in which the fine particles are dispersed on a base film to form a patterned polymer layer;
3) a step of chemically plating a metal film from an electroless plating solution on the polymer layer;
A manufacturing method is disclosed.
As a concrete example of the above process,
1) Add an anionic surfactant and a nonionic surfactant, toluene, and ion-exchanged water and stir until emulsified. Add pyrrole monomer to the resulting emulsifier, add ammonium persulfate to perform oxidative polymerization. Collecting the organic phase and obtaining polypyrrole fine particles (0.001 S / cm) having a reducing performance dispersed in toluene,
2) Superbecamine J-820 was added as a binder, and a polypyrrole paint having a reducing property of polypyrrole: binder resin = 1: 3 (solid content 5%) was prepared, and this was ink jetted onto a polyester film having a thickness of 100 μm. Printing with a printing press to form a patterned polymer layer;
3) The film on which the polymer layer is formed is immersed in a palladium chloride solution and washed with water, and then immersed in an electroless plating bath.
The manufacturing method of the polyester film by which copper plating was given only to the part in which the printing film (polymer layer) was formed by this.
Japanese Patent No. 3208735 JP 2007-270180 A

  Patent Document 1 discloses a method for producing a metallized material using an already polymerized conductive polymer such as polyaniline. In the production method described in Patent Document 1, before conducting plating on a conductive polymer layer by a non-electrochemical method (= electroless) to deposit a metal, the conductive polymer is treated with a chemical such as hydrazine. It is necessary to reduce (= de-dope) with an active reducing agent to activate, and after de-doping, plating is performed without using a catalyst such as Pd to deposit the metal, so that the conductive polymer layer is thickened. It was necessary to apply. As a result, the chemical reduction (= de-doping) of the conductive polymer must be immersed in a strong alkali such as sodium hydroxide for 24 hours at room temperature for a reduced (= de-doped) state. I had to. Therefore, only the base film that can withstand this alkaline treatment liquid for a long time can be used, and the base material that can be used is limited to a specific one, and the treatment reduces the strength of the coating film of polyaniline itself, There was a problem that the adhesiveness with the base film was lowered.

Patent Document 2 discloses plating in which a polymer layer containing a reducing polypyrrole and a binder is formed on a substrate, and a metal film is chemically plated from an electroless plating solution through adsorption of a catalyst such as Pd on the layer. Although a method for producing a film is disclosed, since this method uses a polypyrrole having reducibility, it does not require a chemical reduction (= de-doping) treatment. This is an excellent method in that no problems can occur.
In the plated film described in Patent Document 2, when the ratio of the binder in the coating layer is increased, the polypyrrole having reducibility that is relatively present in the coating layer is decreased. There has been a problem that the reducing ability of the catalyst such as adsorbed Pd is decreased, uneven plating is observed, or plating is not completely deposited.

  The present invention has a metal plating film having excellent adhesion to a substrate using an electroless plating method, and a method for producing a plated product that is uniform with no exposed portions (unevenness) on the surface of the film, and thereby An object is to provide a plated product to be manufactured.

  As a result of diligent investigations to solve the above problems, the present inventors have conducted electroless plating on the coating layer containing reducing polymer fine particles and a binder formed on a substrate through adsorption of a catalytic metal. In the process of forming the metal plating film by the above, if the reduction treatment is performed after the catalytic metal is adsorbed, the reducing ability of the catalytic metal adsorbed on the coating layer is improved, thereby reducing the amount of reducing polymer fine particles. The present invention was completed by finding that a uniform metal plating film having no exposed portion (unevenness) on the surface can be efficiently formed even in the presence of a large amount.

That is, the present invention
(1) A method for producing a plated article,
A) a step of forming a coating layer containing reducing fine polymer particles and a binder on a substrate;
B) Step of adsorbing catalyst metal on the coating layer C) Step of reducing the adsorbed catalyst metal D) Step of performing electroless plating by immersing the substrate subjected to the reduction treatment in a plating bath A method consisting of,
(2) The method according to the above (1), wherein the reducing polymer fine particle is a fine particle which is reduced by conducting a conductive polymer fine particle.
(3) A plated product manufactured by the method for manufacturing a plated product according to (1) or (2),
(4) The plated product according to (3), wherein the average particle diameter of the reducing polymer fine particles is 10 to 100 nm,
It is about.

According to the present invention, even in the presence of a small amount of reducing polymer fine particles, a metal plating film having excellent adhesion to a substrate is provided, and the surface of the film is uniform without any exposed portions (unevenness). A plated product can be manufactured.
In the present invention, the plating can be efficiently performed even in the presence of a small amount of expensive reducing polymer fine particles, so that it can be said to be an excellent method from the economical aspect.
For example, the amount of binder used is usually about 0.1 to 10 parts by weight per 1 part by weight of the reducing fine polymer particles. When the amount used exceeds 10 parts by weight, the exposed part (unevenness) is not necessarily present. However, in the method for producing a plated product according to the present invention, there is no exposed portion (unevenness) stably even when the amount used exceeds 10 parts by mass. A uniform metal plating film can be formed, and the metal plating film has excellent adhesion to the substrate (having a peel strength of 1.0 kgf / cm or more in a tape test).

The plated product of the present invention can be produced in the same manner by using not only reducing polymer fine particles but also conductive polymer fine particles. In this case, before conducting electroless plating, it is necessary to dedope the conductive polymer fine particles to make them reducible. However, in the plated product of the present invention, a relatively thin layer (conductive polymer fine particle layer) ) Can maintain excellent adhesion and uniformity.
And since the conductive polymer fine particle layer can be made relatively thin, the de-doping can be achieved even in a short time alkali treatment to form a coating film layer. The problem of deterioration in performance can be avoided.

即ち、還元性の高分子微粒子（ポリピロール）がパラジウムイオンを還元することにより、高分子微粒子上にパラジウム（金属）が吸着されるが、これにより、高分子微粒子（ポリピロール）はイオン化される、即ち、パラジウムによりドーピングされた状態となり、結果として導電性を発現する。 In addition, the plated product of the present invention, for example, reduces and adsorbs a catalytic metal such as palladium on a coating layer containing reducible polymer fine particles formed on a substrate, and adsorbs the catalytic metal such as palladium. It is manufactured by forming a metal plating film on the coated film layer, but the catalytic metal such as palladium adsorbed on the coated film layer is reduced and adsorbed from the XPS analysis result. It has been found that there is a mixture of a substance (for example, zero-valent palladium) and a substance that is adsorbed without reduction (for example, divalent palladium).
When a catalytic metal such as palladium is reduced and adsorbed on the polymer fine particles, for example, in the case of polypyrrole, it is considered that the state shown in the following figure is obtained.

That is, the reducing polymer fine particles (polypyrrole) reduce palladium ions to adsorb palladium (metal) on the polymer fine particles, whereby the polymer fine particles (polypyrrole) are ionized. And doped with palladium, and as a result, develops conductivity.

In the present invention, the main feature is to improve the reduction ability of the catalyst metal such as palladium by performing a reduction treatment after adsorbing the catalyst metal such as palladium in electroless plating. The mechanism by which the reducing ability of the catalytic metal such as palladium is improved is as follows.
In order for Pd to exhibit an action as a catalyst for electroless plating, it is important that it exists in a zero valence (metal state). When the amount of reducing polymer fine particles is large, Pd (0 The amount of the metal plating film is easily increased, and as a result, the metal plating film is easily formed.
On the other hand, when the amount of the reducing fine polymer particles decreases, the total amount of Pd (0 valence) and Pd (2 valence) adsorbed on the coating layer decreases, and as a result, the relative amount of Pd (0 valence) is relatively reduced. Since the abundance is reduced, the catalytic action is weakened and the plating is difficult to deposit.
As described above, the reduction treatment reduces Pd (divalent) to Pd (zero valent) even when the total amount of Pd (zero valent) and Pd (divalent) decreases, It is considered that the abundance of Pd (zero valence) was increased, thereby enhancing the catalytic activity and improving the deposition of the plating.
The above mechanism can be confirmed from the XPS analysis result, for example, as shown in FIG.
As can be seen from FIG. 1, the reduced coating film (solid line) has a lower Pd (divalent) (denoted as Pd2 + in the table) than the non-reduced coating film (dotted line), and Pd ( 0 value) (denoted as Pd in the table) increases.

The present invention will be described in more detail.
The present invention is a method for producing a plated article,
A) a step of forming a coating layer containing reducing fine polymer particles and a binder on a substrate;
B) Step of adsorbing catalyst metal on the coating layer C) Step of reducing the adsorbed catalyst metal D) Step of performing electroless plating by immersing the substrate subjected to the reduction treatment in a plating bath Relates to a method comprising:

  The reducing polymer fine particle used in the present invention is a π-conjugated double in an O / W type emulsion obtained by mixing and stirring an organic solvent, water, an anionic surfactant and a nonionic surfactant. It is produced by adding a monomer having a bond and subjecting the monomer to oxidative polymerization.

The monomer having a π-conjugated double bond is not particularly limited as long as it is a monomer used for producing a conductive polymer, and examples thereof include pyrrole, N-methylpyrrole, N-ethylpyrrole, and N-phenyl. Pyrrole, N-naphthylpyrrole, N-methyl-3-methylpyrrole, N-methyl-3-ethylpyrrole, N-phenyl-3-methylpyrrole, N-phenyl-3-ethylpyrrole, 3-methylpyrrole, 3- Ethyl pyrrole, 3-n-butyl pyrrole, 3-methoxy pyrrole, 3-ethoxy pyrrole, 3-n-propoxy pyrrole, 3-n-butoxy pyrrole, 3-phenyl pyrrole, 3-toluyl pyrrole, 3-naphthyl pyrrole, 3 -Phenoxypyrrole, 3-methylphenoxypyrrole, 3-aminopyrrole, 3-dimethyla Pyrrole derivatives such as nopyrrole, 3-diethylaminopyrrole, 3-diphenylaminopyrrole, 3-methylphenylaminopyrrole and 3-phenylnaphthylaminopyrrole, aniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, o- Aniline derivatives such as methoxyaniline, m-methoxyaniline, p-methoxyaniline, o-ethoxyaniline, m-ethoxyaniline, p-ethoxyaniline, o-methylaniline, m-methylaniline and p-methylaniline, thiophene, 3 -Methylthiophene, 3-n-butylthiophene, 3-n-pentylthiophene, 3-n-hexylthiophene, 3-n-heptylthiophene, 3-n-octylthiophene, 3-n-nonylthiophene, 3-n- Decylthiophene, Examples include thiophene derivatives such as 3-n-undecylthiophene, 3-n-dodecylthiophene, 3-methoxythiophene, 3-naphthoxythiophene and 3,4-ethylenedioxythiophene, preferably pyrrole, aniline, thiophene And 3,4-ethylenedioxythiophene and the like, more preferably pyrrole.

Various anionic surfactants used in the production can be used, but those having a plurality of hydrophobic ends (for example, those having a branched structure in a hydrophobic group or those having a plurality of hydrophobic groups) are preferred. . By using such an anionic surfactant having a plurality of hydrophobic ends, stable micelles can be formed, and separation between the aqueous phase and the organic solvent phase is smooth after the polymerization. Reducible polymer fine particles dispersed in are easily available.
Among anionic surfactants having multiple hydrophobic ends, di-2-ethylhexyl sodium sulfosuccinate (4 hydrophobic ends), di-2-ethyloctyl sodium sulfosuccinate (4 hydrophobic ends) and branched type Alkyl benzene sulfonate (two hydrophobic ends) can be preferably used.

  The amount of the anionic surfactant in the reaction system is preferably less than 0.05 mol, more preferably 0.005 mol to 0.03 mol, with respect to 1 mol of the monomer having a π-conjugated double bond. When the amount is 0.05 mol or more, the added anionic surfactant acts as a dopant, and the resulting fine particles exhibit conductivity. Therefore, in order to perform electroless plating using this, a dedoping step is required.

  Nonionic surfactants include, for example, polyoxyethylene alkyl ethers, alkyl glucosides, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbidic fatty acid esters, polyoxyethylene fatty acid esters, fatty acid alkanolamides, poly Examples include oxyethylene alkylphenyl ethers. These may be used alone or in combination. In particular, those that stably form an O / W emulsion are preferred.

The amount of the nonionic surfactant in the reaction system is preferably 0.2 mol or less, more preferably 0.2 mol or less with respect to 1 mol of the monomer having a π-conjugated double bond, in addition to the anionic surfactant. It is 05-0.15 mol. If it is less than 0.05mol decreases the yield and dispersion stability, whereas, after Polymerization at least 0.2 mol, separation of the aqueous and organic solvent phases becomes difficult, reducing polymer in the organic solvent phase This is not preferable because fine particles cannot be obtained.

  In the production, the organic solvent forming the organic phase of the emulsion is preferably hydrophobic. Among these, toluene and xylene, which are aromatic organic solvents, are preferable from the viewpoint of the stability of the O / W emulsion and the affinity with the monomer having a π-conjugated double bond. Although the amphoteric solvent can polymerize a monomer having a π-conjugated double bond, it is difficult to separate the organic phase and the aqueous phase when the produced reducing polymer fine particles are recovered.

  The ratio of the organic phase to the aqueous phase in the emulsion is preferably 75% by volume or more in the aqueous phase. When the water phase is 20% by volume or less, the amount of the monomer having a π-conjugated double bond is reduced, and the production efficiency is deteriorated.

Examples of the oxidizing agent used in the production include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and chlorosulfonic acid, organic acids such as alkylbenzenesulfonic acid and alkylnaphthalenesulfonic acid, potassium persulfate, ammonium persulfate and peroxidation. Peroxides such as hydrogen can be used. These may be used alone or in combination of two or more. Even a Lewis acid such as ferric chloride can polymerize a monomer having a π-conjugated double bond, but the produced particles may aggregate and be unable to be finely dispersed. Particularly preferred oxidizing agents are persulfates such as ammonium persulfate.

  The amount of the oxidizing agent in the reaction system is preferably 0.1 mol or more and 0.8 mol or less, more preferably 0.2 to 0.6 mol with respect to 1 mol of the monomer having a π-conjugated double bond. is there. If the amount is less than 0.1 mol, the degree of polymerization of the monomer decreases, making it difficult to separate and collect the polymer fine particles. On the other hand, if the amount is 0.8 mol or more, the particles are aggregated to increase the particle size of the polymer fine particles, resulting in poor dispersion stability To do.

The polymer fine particle production method is performed, for example, in the following steps:
(A) a step of preparing an emulsion by mixing and stirring an anionic surfactant, a nonionic surfactant, an organic solvent and water;
(B) a step of dispersing a monomer having a π-conjugated double bond in an emulsion,
(C) oxidative polymerization of the monomer,
(D) A step of separating the organic phase and collecting the polymer fine particles.

  Each of the above steps can be performed using means known to those skilled in the art. For example, the mixing and stirring performed at the time of preparing the emulsion is not particularly limited. For example, a magnetic stirrer, a stirrer, a homogenizer, or the like can be selected as appropriate. The polymerization temperature is 0 to 25 ° C, preferably 20 ° C or less. If the polymerization temperature exceeds 25 ° C., side reactions occur, which is not preferable.

  When the oxidative polymerization reaction is stopped, the reaction system is divided into an organic phase and an aqueous phase. At this time, unreacted monomers, oxidizing agents and salts remain dissolved in the aqueous phase. When the organic phase is separated and recovered and washed several times with ion-exchanged water, reducing polymer fine particles dispersed in an organic solvent can be obtained.

The polymer fine particles obtained by the above production method are fine particles mainly composed of a polymer of a monomer derivative having a π-conjugated double bond and containing an anionic surfactant and a nonionic surfactant. And the characteristic is that it has a fine particle size and is dispersible in an organic solvent.
The polymer fine particles are spherical fine particles, and the average particle size is preferably 10 to 100 nm.
By making fine particles with a small average particle diameter as described above, the surface area of the fine particles becomes extremely large, and even with fine particles of the same mass, more catalytic metals can be adsorbed, thereby reducing the thickness of the coating layer. It becomes possible.
The conductivity of the obtained polymer fine particles is less than 0.01 S / cm, and preferably 0.005 S / cm or less.

The reductive polymer fine particles dispersed in the organic solvent thus obtained can be used as the reductive polymer fine particle component of the coating as it is, after being concentrated or dried.
Further, for example, commercially available reducing polymer fine particles may be used as a component of the coating material, instead of the reducing polymer fine particles produced as described above.

The coating material used in the present invention is a coating material containing reducing fine polymer particles and a binder.
Examples of the binder include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, poly (N-vinylcarbazole), hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, acetic acid. Examples thereof include vinyl, ABS resin, polyurethane resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, and silicon resin.
The amount of the binder used is preferably 5 to 50 parts by mass with respect to 1 part by mass of the reducing polymer fine particles. If the binder exceeds 50 parts by mass, metal plating may be difficult to deposit, and if the binder is less than 5 parts by mass, it may be difficult to obtain excellent adhesion.

  The solvent that can be included in the paint is not particularly limited as long as it can dissolve the binder, but those that can largely dissolve the substrate are not preferable. However, it is possible to use a solvent that greatly dissolves the base material by reducing the solubility by mixing it with another low-solubility solvent.

Examples of the solvent include aliphatic esters such as butyl acetate, aromatic solvents such as toluene, ketones such as methyl ethyl ketone, cyclic saturated hydrocarbons such as cyclohexane, chain saturated hydrocarbons such as n-octane, Examples thereof include chain saturated alcohols such as methanol, ethanol and n-octanol, aromatic esters such as methyl benzoate, aliphatic ethers such as diethyl ether, and mixtures thereof.
Furthermore, the coating material used in the present invention can be added with a resin such as a dispersion stabilizer, a thickening agent, and an ink binder, depending on the application, application object, and the like.

The substrate is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate, acrylic resins such as polymethyl methacrylate, polypropylene resins, polycarbonate resins, polystyrene resins, polyvinyl chloride resins, polyamide resins, polyimide resins, and glass. Can be mentioned.
Moreover, although the shape of a base material is not specifically limited, For example, plate shape and a film form are mentioned.
In addition, examples of the base material include a resin molded product obtained by molding a resin by injection molding or the like. And, by providing the plated product of the present invention on this resin molded product, for example, a decorative plated product for automobiles can be produced.

  The coating method on the substrate is not particularly limited, for example, using a spray, a screen printing machine, a gravure printing machine, a flexographic printing machine, an inkjet printing machine, an offset printing machine, dipping, a spin coater, a roll coater, etc. Can be coated.

The thickness of the coating layer is preferably 20 nm to 100 μm.
When the thickness is less than 20 nm, metal plating may be difficult to deposit, and when the thickness exceeds 100 μm, it may be difficult to obtain excellent adhesion.

  The plated product of the present invention can also be produced in the same manner by using fine particles that have been reduced by conducting conductive polymer fine particles as the reducing polymer fine particles.

  For example, the conductive polymer fine particles used are prepared by adding a monomer having a π-conjugated double bond to an O / W type emulsion obtained by mixing and stirring an organic solvent, water, and an anionic surfactant. The monomer can be produced by oxidative polymerization.

  Examples of the monomer having an π-conjugated double bond and the anionic surfactant are the same as those exemplified in the production of the reducing fine particles, and preferably pyrrole, aniline, thiophene and 3,4- Ethylenedioxythiophene etc. are mentioned, More preferably, pyrrole is mentioned.

The amount of the anionic surfactant in the reaction system is preferably less than 0.2 mol, more preferably 0.05 mol to 0.15 mol, with respect to 1 mol of the monomer having a π-conjugated double bond. If it is less than 0.05 mol, the yield and dispersion stability decrease, while 0.2%
If it is more than mol, the resulting conductive polymer fine particles may have a conductivity humidity dependency.

  In the production, the organic solvent forming the organic phase of the emulsion is preferably hydrophobic. Among these, toluene and xylene, which are aromatic organic solvents, are preferable from the viewpoint of the stability of the O / W emulsion and the affinity with the monomer. Although the amphoteric solvent can polymerize a monomer having a π-conjugated double bond, it becomes difficult to separate the organic phase and the aqueous phase when the produced conductive polymer fine particles are recovered.

  The ratio of the organic phase to the aqueous phase in the emulsion is preferably 75% by volume or more in the aqueous phase. When the water phase is 20% by volume or less, the amount of the monomer having a π-conjugated double bond is reduced, and the production efficiency is deteriorated.

Examples of the oxidizing agent used in the production include the same as those exemplified in the production of the reducing fine particles, but a particularly preferred oxidizing agent is a persulfate such as ammonium persulfate.
The amount of the oxidizing agent in the reaction system is preferably 0.1 mol or more and 0.8 mol or less, more preferably 0.2 to 0.6 mol with respect to 1 mol of the monomer having a π-conjugated double bond. is there. If the amount is less than 0.1 mol, the degree of polymerization of the monomer decreases, making it difficult to separate and collect the conductive polymer fine particles. On the other hand, if the amount is 0.8 mol or more, the particles are aggregated to increase the particle size of the conductive polymer fine particles. , Dispersion stability deteriorates.

The method for producing the conductive polymer fine particles is performed, for example, in the following steps:
(A) a step of preparing an emulsion by mixing and stirring an anionic surfactant, an organic solvent and water;
(B) a step of dispersing a monomer having a π-conjugated double bond in an emulsion,
(C) a step of oxidatively polymerizing the monomer and causing the anionic surfactant to contact and adsorb the polymer fine particles;
(D) A step of separating the organic phase and collecting the conductive polymer fine particles.

  Each of the above steps can be performed using means known to those skilled in the art. For example, the mixing and stirring performed at the time of preparing the emulsion is not particularly limited. For example, a magnetic stirrer, a stirrer, a homogenizer, or the like can be selected as appropriate. The polymerization temperature is 0 to 25 ° C, preferably 20 ° C or less. If the polymerization temperature exceeds 25 ° C., side reactions occur, which is not preferable.

  When the oxidative polymerization reaction is stopped, the reaction system is divided into an organic phase and an aqueous phase. At this time, unreacted monomers, oxidizing agents and salts remain dissolved in the aqueous phase. When the organic phase is separated and recovered and washed several times with ion-exchanged water, conductive polymer fine particles dispersed in an organic solvent can be obtained.

The conductive polymer fine particles obtained by the above production method are fine particles mainly composed of a monomer derivative having a π-conjugated double bond and containing an anionic surfactant. And the characteristic is that it can disperse | distribute in a fine particle size and an organic solvent.
The polymer fine particles are spherical fine particles, and the average particle size is preferably 10 to 100 nm.
By using fine particles with a small average particle size as described above, the surface area of the fine particles becomes extremely large, and even with fine particles of the same mass, more catalyst metal can be adsorbed when dedoped and reduced. Thus, the coating layer can be made thin.

The conductive polymer fine particles dispersed in the organic solvent thus obtained can be used as the conductive polymer fine particle component of the coating as it is, after being concentrated or dried.
Further, for example, commercially available conductive polymer fine particles can be used as a component of the paint, instead of the conductive polymer fine particles produced as described above.

The coating material containing the conductive polymer fine particles and the binder described above is applied onto a substrate to form a coating layer, and then a dedoping treatment is performed to make the fine particles reducible. An existing coating layer is formed.

  Examples of the binder are the same as those exemplified above, and the amount of the binder used is preferably 5 to 50 parts by mass with respect to 1 part by mass of the reducing polymer fine particles. If the binder exceeds 50 parts by mass, metal plating may be difficult to deposit, and if the binder is less than 5 parts by mass, it may be difficult to obtain excellent adhesion.

The solvent that can be included in the paint is not particularly limited as long as it can dissolve the binder, but those that can largely dissolve the substrate are not preferable. However, it is possible to use a solvent that greatly dissolves the base material by reducing the solubility by mixing it with another low-solubility solvent.
Examples of the solvent include aliphatic esters such as butyl acetate, aromatic solvents such as toluene, ketones such as methyl ethyl ketone, cyclic saturated hydrocarbons such as cyclohexane, chain saturated hydrocarbons such as n-octane, Examples thereof include chain saturated alcohols such as methanol, ethanol and n-octanol, aromatic esters such as methyl benzoate, aliphatic ethers such as diethyl ether, and mixtures thereof.
Furthermore, the coating material used in the present invention can be added with a resin such as a dispersion stabilizer, a thickening agent, and an ink binder, depending on the application, application object, and the like.

Examples of the substrate include those similar to those exemplified above, and the shape thereof is not particularly limited, and examples thereof include a plate shape and a film shape.
In addition, examples of the base material include a resin molded product obtained by molding a resin by injection molding or the like. And, by providing the plated product of the present invention on this resin molded product, for example, a decorative plated product for automobiles can be produced.

  The coating method on the substrate is not particularly limited, for example, using a spray, a screen printing machine, a gravure printing machine, a flexographic printing machine, an inkjet printing machine, an offset printing machine, dipping, a spin coater, a roll coater, etc. Can be coated.

The thickness of the coating layer is preferably 20 nm to 100 μm.
When the thickness is less than 20 nm, metal plating may be difficult to deposit, and when the thickness exceeds 100 μm, it may be difficult to obtain excellent adhesion.

The layer formed using the conductive polymer fine particles is subjected to dedoping treatment in order to make the fine particles reducible.
As the dedoping treatment, a reducing agent, for example, a borohydride compound such as sodium borohydride or potassium borohydride, an alkylamine borane such as dimethylamine borane, diethylamine borane, trimethylamine borane, triethylamine borane, hydrazine, etc. The method of processing and reducing with the solution to contain, or the method of processing with an alkaline solution is mentioned.

It is preferable to treat with an alkaline solution from the viewpoint of operability and economy.
In particular, since the layer formed using the conductive polymer fine particles is relatively thin, it is possible to achieve dedoping by a brief alkali treatment under mild conditions.
For example, it is treated in a 1M aqueous sodium hydroxide solution at a temperature of 20 to 50 ° C., preferably 30 to 40 ° C., for 1 to 30 minutes, preferably 3 to 10 minutes.

The base material on which the coating layer is formed as described above is made into a plated product by electroless plating through adsorption of a catalytic metal. In the present invention, the following steps are included.
B) Step of adsorbing catalytic metal on the coating layer C) Step of reduction treatment D) Step of electroless plating by dipping in a plating bath That is, for attaching a catalytic metal such as palladium chloride to the substrate. After being immersed in this catalyst solution, washing with water, etc., and after performing a reduction treatment, a plated product can be obtained by immersing in an electroless plating bath.

Step B) The catalyst solution is a solution containing a noble metal (catalyst metal) having catalytic activity for electroless plating, and examples of the catalyst metal include palladium, gold, platinum, rhodium, etc. Well, a palladium compound is preferable from the viewpoint of stability including a catalytic metal, and among these, palladium chloride is particularly preferable.
A preferred specific catalyst solution includes 0.02% palladium chloride-0.01% hydrochloric acid aqueous solution (pH 3).
The treatment temperature is 20 to 50 ° C., preferably 30 to 40 ° C., and the treatment time is 0.1 to 20 minutes, preferably 1 to 10 minutes.
By the above operation, the reducing polymer fine particles in the coating film become conductive polymer fine particles as a result.

Step C) Next, a reduction treatment is performed on the base material to which a catalytic metal such as palladium chloride is attached.
The reduction treatment is performed by bringing the substrate into contact with an aqueous solution containing a reducing agent. As the reducing agent, a water-soluble compound having a reducing action can be used. Specific examples include amine boranes such as dimethylamine borane (DMAB) and trimethylamine borane (TMAB); potassium borohydride, sodium borohydride and the like. Borohydride compounds; hypophosphites such as sodium hypophosphite and potassium hypophosphite; aldehydes such as formalin; hydrazine and the like.
A reducing agent can be used individually by 1 type or in mixture of 2 or more types. The concentration of the reducing agent is preferably about 0.001 to 0.5 mol / L, and more preferably about 0.01 to 0.2 mol / L. The pH of the aqueous solution is not particularly limited, and may be appropriately set in a range where the reducing performance is good and the stability of the reducing agent is not hindered according to the type of the reducing agent used. Usually, the pH is preferably about 3 or more.

Step D) The substrate treated as described above is immersed in a plating solution for depositing metal, thereby forming an electroless plating film.
The plating solution is not particularly limited as long as it is a plating solution usually used for electroless plating.
That is, metal, copper, gold, silver, nickel, chromium, etc. that can be used for electroless plating can all be applied, but copper is preferred.
Specific examples of the electroless copper plating bath include, for example, an ATS add copper IW bath (Okuno Pharmaceutical Co., Ltd.).
The treatment temperature is 20 to 50 ° C., preferably 30 to 40 ° C., and the treatment time is 1 to 30 minutes, preferably 5 to 15 minutes.

As described above, since the reducing polymer fine particles in the coating film become conductive polymer fine particles as a result, the coating film containing the conductive polymer fine particles and the binder on the surface of the substrate by the above operation. A plated product in which a metal plating film is formed by an electroless plating method on the coating layer, and has a metal plating film excellent in adhesion to a substrate, and the surface of the film is A plated product having no exposed portion (unevenness) and uniform is manufactured.

EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to an Example.
Example 1: Production of plated product <Preparation of paint containing reducing polypyrrole fine particles>
Anionic surfactant Perex OT-P (manufactured by Kao Corporation) 0.42 mmol, polyoxyethylene alkyl ether nonionic surfactant Emulgen 409P (manufactured by Kao Corporation) 2.12 mmol, toluene 50 mL, ion-exchanged water 100 mL were added. The mixture was stirred until emulsification while maintaining at 20 ° C. To the obtained emulsion, 21.2 mmol of pyrrole monomer was added and stirred for 1 hour, and then 4 mmol of ammonium persulfate was added to conduct a polymerization reaction for 2 hours. After completion of the reaction, the organic layer was collected and washed several times with ion-exchanged water to obtain reducing polypyrrole fine particles having reducing performance dispersed in toluene.
The solid content of the reducing polypyrrole fine particles in the toluene dispersion obtained above was about 1.2%. Superbeccamin J-820 (Dainippon Ink Chemical Co., Ltd.) was used as a binder here. Manufactured butylated melamine resin) was added at a mixing ratio of 30 parts by mass with respect to 1 part by mass of the reducing polypyrrole fine particles to prepare a reducing polypyrrole paint.
<Formation of coating layer>
The obtained paint was thinly coated on a 100 μm thick PET film with a bar coater (No. 8), and dried at 120 ° C. for 5 minutes to form a coating film.
<Plating treatment>
The film on which the coating layer produced above was formed was immersed in a 100 ppm palladium chloride-0.01 M hydrochloric acid aqueous solution at 35 ° C. for 5 minutes, and then washed with ion-exchanged water. Next, it was immersed in a 0.5 M aqueous sodium phosphinate solution at 40 ° C. for 1 minute and then washed with ion-exchanged water. Next, the film was dipped in an electroless copper plating bath ATS Adcopper IW bath (Okuno Pharmaceutical Co., Ltd.), and dipped at 35 ° C. for 10 minutes for copper plating. Then, thickening was performed to a copper film thickness of 40 μm by copper sulfate plating (electroplating).

Example 2
A plated product was obtained by performing the same operation as in Example 1 except that the reducing agent 0.5M sodium phosphinate aqueous solution was changed to a 0.1M formalin aqueous solution.

Example 3
A plated product was obtained by performing the same operation as in Example 1 except that the reducing agent 0.5M sodium phosphinate aqueous solution was changed to a 0.1M dimethylamine borane aqueous solution.

Example 4
Super Becamine J-820 as a binder: Melamine (Dainippon Ink Chemical Co., Ltd.)
Except for changing byron 240: polyester (made by Toyobo Co., Ltd.)
By performing the same operation as in Example 1, a plated product was obtained.

Example 5: Production of plated product using reducing polyaniline fine particles Anionic surfactant Perex OT-P (manufactured by Kao Corporation) 0.42 mmol, sorbitan fatty acid ester nonionic surfactant rheodol SP-O30V (manufactured by Kao Corporation) ) 0.424 mmol and polyoxyethylene sorbidan fatty acid ester (trade name: Rheodor TW-O320V) 2.12 mmol (manufactured by Kao Corporation), toluene 50 mL, and ion-exchanged water 100 mL until emulsified while maintaining at 20 ° C. Stir. To the obtained emulsion, 21.2 mmol of aniline monomer was added and stirred for 1 hour, and then 4 mmol of ammonium persulfate was added to conduct a polymerization reaction for 2 hours. After completion of the reaction, the organic layer was collected and washed several times with ion-exchanged water to obtain reducible polyaniline fine particles having reducing performance dispersed in toluene. The solid content of the reducing polyaniline fine particles in the toluene dispersion obtained here was about 1.4%. Superbeccamin J-820 (Dainippon Ink Chemical Co., Ltd.) was used as a binder here. Was added at a compounding ratio of 30 parts by mass with respect to 1 part by mass of the reducing polyaniline fine particles to obtain a reducing polyaniline paint.
The obtained paint was coated and plated in the same manner as in Example 1.

Comparative Example 1
As a result of performing the same operation as in Example 1 except that the reduction treatment was not performed, the substrate was exposed and was not completely covered.

Test example 1
The plated products of Examples 1 to 5 and Comparative Example 1 manufactured above were subjected to various evaluation tests and the results are summarized in Table 1.
The evaluation test items, evaluation methods and evaluation criteria are as follows.
-Plating appearance The state of the plating film was observed visually, and the substrate exposed area was measured.
The evaluation criteria were as follows.
○: Completely covered and deposited without unevenness.
Δ: Completely covered but partially uneven.
X: There is a base material exposed part and it is not completely covered.
-Tape test According to the JIS H8504 tape test method, 100 pieces of 2 mm square strips were made with a cutter, and then a peeling test with a tape was performed.
The evaluation criteria were as follows.
○: No peeling ×: Peeling / peel strength Measurement was performed according to JIS C6741.
Moreover, A thru | or G in Table 1 mean the following, and the quantity of a binder shows the mass part number of the binder used with respect to 1 mass part of reducing polymer microparticles | fine-particles.
A: Super Becamine J-820: Melamine (Dainippon Ink Chemical Co., Ltd.)
B: Byron 240: Polyester (Toyobo Co., Ltd.)
C: Reducing polypyrrole D: Reducing polyaniline E: 0.5 M sodium phosphinate aqueous solution F: 0.1 M formalin aqueous solution G: 0.1 M dimethylamine borane aqueous solution

It is a graph which shows the analysis result of XPS showing the presence condition of Pd (0 valence) and Pd (2 valence) when not carrying out reduction processing of the coating film layer in which Pd was adsorbed.

Claims (4)

A method for producing a plated article,
A) a step of forming a coating layer containing reducing fine polymer particles and a binder on a substrate;
B) Step of adsorbing catalyst metal on the coating layer C) Step of reducing the adsorbed catalyst metal D) Step of performing electroless plating by immersing the substrate subjected to the reduction treatment in a plating bath A method consisting of: The method according to claim 1, wherein the reducing polymer fine particles are made fine particles that have been reduced by dedoping conductive polymer fine particles. A plated product produced by the method for producing a plated product according to claim 1 or 2. The plated article according to claim 3, wherein the average particle diameter of the reducing polymer fine particles is 10 to 100 nm.

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