JP2014194055A - Coating for plating ground, method of producing plating ground coat layer and method of plated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating for plating ground, a method of producing a plating ground coat and method of producing a plated article.SOLUTION: A ground coating for forming a metal film on a substrate by electroless plating contains an aniline type conductive polymer (A) having acidic groups, and the aniline type conductive polymer is a conductive polymer (A-1) having repeating units of formula (1), where, Rto Rare independently a hydrogen atom, a 1-24C linear or branched alkyl group, a 1-24C linear or branched alkoxy group, an acidic group, a hydroxy group, a nitro group or a halogen atom and at least one of R-Ris an acid group or its salt. A ground coating containing a water-soluble polymer (B) additionally, a method of producing the ground coating and a method of producing a plated article are also provided.

Description

  The present invention relates to a coating base coating material, a method for manufacturing a plating base coating layer using the coating material, and a method for manufacturing a plated product.

A technique of applying a patterned plating on a base material is applied to creation of an electric circuit such as a printed wiring board. A conventional electric circuit such as a printed wiring board is a photomask having a desired pattern by coating a photoresist material such as a photosensitive polymer on an insulating substrate covered with a metal material such as copper, gold, or tin oxide. Irradiate ultraviolet rays, etc. to cure the photoresist material of the irradiated part, remove the uncured resist material, and then remove unnecessary copper foil parts etc. by chemical etching to form a circuit. It was.
However, these methods have complicated processes, and there are problems such as wasteful consumption of resources and energy as well as heavy environmental load, such as removal of resist material and dissolution and removal of most metals by etching. there were.
As a method for solving such a problem, several electroless plating methods for forming an electric circuit by forming a conductive polymer layer on a base material and plating the conductive polymer layer have been proposed. ing.

For example, as a method of non-electrochemically depositing a metal on a substrate, a coating material containing polyaniline is reduced with a chemical reducing agent, and a metallized material for attaching a metal to a material from a metal ion-containing solution is produced. A method (Patent Document 1) has been proposed.
In addition, after reducing polypyrrole fine particles printed on a substrate, a metal plating film is formed by electroless plating on a coating film in which a catalytic metal such as palladium is adsorbed on the coating surface (patent) Document 2) is described.

Japanese National Patent Publication No. 10-511433 JP 2007-270180 A

However, in the manufacturing method described in Patent Document 1, before conducting plating on a conductive polymer layer by a non-electrochemical method to deposit a metal, the conductive polymer is reduced with a chemical reducing agent such as hydrazine. Need to be activated.
Furthermore, since reduction with hydrazine or the like is performed by a long-time treatment under alkaline conditions, the base material used is limited to those that can withstand alkaline conditions. There were problems such as a decrease in strength.
Moreover, since the coating material in which the polymer fine particles are dispersed in Patent Document 2 uses an organic solvent as a solvent, a printing method that has been originally used as a printing method for water-based ink, for example, inkjet printing, offset printing, It is difficult to apply to gravure offset printing, flexographic printing, etc., and the conductive polymer fine particles were immersed in an aqueous solution of sodium hydroxide, and the process was complicated with dedoping treatment.

  As a result of intensive studies, the present inventors have been made in view of the above problems, and by using a base coating containing an aniline-based conductive polymer (A) having an acidic group, the environmental load is low and adhesion is achieved. The present inventors have found that a plated product having excellent properties can be obtained, and have completed the present invention.

That is, this invention has the following aspect.
[1] A base paint for forming a metal film on a substrate by an electroless plating method, wherein the base paint includes an aniline-based conductive polymer (A) having an acidic group.
[2] The base according to [1], wherein the aniline-based conductive polymer (A) having an acidic group is a conductive polymer (A-1) having a repeating unit represented by the following general formula (1): paint.
[3] The base coating according to [1] or [2], further including a water-soluble polymer (B).
[4] An undercoat coating layer that is applied to the base material according to any one of [1] to [3] above and heat-treats the coating layer formed thereby. Production method.
[5] A method for producing a plated product, wherein a metal film is chemically plated from an electroless plating solution on the underlying coating film layer described in [4].

In formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxyl group, a nitro group or a halogen atom. Further, at least one of R ^{1 to} R ⁴ is an acidic group or a salt thereof.

The paint of the present invention can be applied to printing methods that have been used as printing methods for water-based inks, such as ink jet printing, offset printing, gravure offset printing, flexographic printing, etc. A paint that does not require a reduction treatment or the like can be provided.
Furthermore, by using the paint, it is possible to provide a method by which a plated product with low environmental load and excellent adhesion can be easily produced.

Hereinafter, the present invention will be described in detail.
In the present invention, “soluble” means water, water containing a base and a basic salt, water containing an acid, a solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, or a mixture thereof (10 g (liquid temperature 25). ℃) means that 0.1 g or more is uniformly dissolved.

<Aniline-based conductive polymer (A) having an acidic group>
The aniline-based conductive polymer (A) having an acidic group exhibits good solubility and conductivity by having an acidic group in the polymer molecule.

<Aniline-based conductive polymer (A-1) having an acidic group>
The conductive polymer (A) preferably has a repeating unit represented by the following general formula (1) from the viewpoint of solubility.

In formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxyl group, a nitro group, and a halogen atom. Further, at least one of R ^{1 to} R ⁴ is an acidic group or a salt thereof.

  The conductive polymer (A) is a substituted or unsubstituted aniline, thiophene, pyrrole, as a structural unit other than that represented by the general formula (1), as long as it does not affect solubility, conductivity and properties. It may contain at least one structural unit of phenylene, vinylene, other divalent unsaturated groups and divalent saturated groups.

  The conductive polymer (A) preferably contains 70% or more, preferably 80% or more of the repeating unit of the general formula (1), that is, the content of acidic groups with respect to the aromatic ring from the viewpoint of solubility. Is more preferable, and 90% or more is more preferable.

The weight average molecular weight of the conductive polymer (A) is preferably 3,000 to 500,000, more preferably 5,000 to 200,000 in terms of film formability and film strength in terms of sodium polystyrene sulfonate. 10000 to 100,000 are more preferable.
The conductive polymer (A) is preferably polyaniline having a conductivity of 0.1 S / cm or less, preferably 0.05 S / cm or less.
Furthermore, the conductive polymer preferably has a structure represented by the following general formula (2). Further, from the viewpoint of conductivity and plating film formability, the ratio of x: y is preferably 10: 0 to 5: 5, and particularly preferably 9: 1 to 6: 4.

In formula (2), R ^{5 to} R ²⁰ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxyl group, a nitro group, and a halogen atom. In addition, at least one of R ^{5 to} R ²⁰ is an acidic group. Further, x, y, and n each represent the degree of polymerization.

<Water-soluble polymer (B)>
The water-soluble polymer (B) used in the present invention is a binder (binder), and the water-soluble polymer (B) is not particularly limited. For example, polyacrylamide, polyvinyl alcohol, polyethylene oxide And water-soluble polymers such as polycarboxylic acids and polyanions, water-soluble curable resins such as epoxy resins, urethane resins, and melamine resins, and emulsions such as acrylic resins, polyether-based urethane resins, and polyester-based urethane resins.

The amount of the water-soluble polymer (B) used can be 0.1 parts by mass or more with respect to 1 part by mass of the conductive polymer (A), specifically, 1 part by mass of the conductive polymer (A). It is preferable that it is the range of 0.1 mass part-60 mass parts with respect to a part.
If the water-soluble polymer (B) exceeds 60 parts by mass, metal plating may be difficult to deposit, and if the water-soluble polymer (B) is less than 0.1 parts by mass, the adhesion between the substrate and the coating layer will be reduced. Tend to be inferior.

The base coating material of the present invention may contain water as a solvent in addition to the above components.
In addition, the coating material may further contain a dispersion stabilizer, a thickener, an ink binder, or the like, depending on the application, application object, or the like.

In the present invention, a base coating containing the conductive polymer (A) can be applied onto a substrate, whereby a coating layer for plating base can be produced.
Specifically, a base paint composed of an aqueous solution containing the conductive polymer (A) is applied, and the conductive polymer (A) in the coating layer formed thereby is heat-treated to remove acidic groups. The coating layer for plating base can be manufactured.

Although it does not specifically limit as a base material used for this invention, For example, acrylic resins, such as polyester resins, such as a polyethylene terephthalate, a polymethylmethacrylate, a polypropylene resin, a polycarbonate resin, a polystyrene resin, a polyvinyl chloride resin, a polyamide resin, a polyimide resin , Glass, metal, wood, paper and the like.
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 the resin molded product, for example, a decorative plated product for automobiles can be prepared, or the plated product of the present invention on a film made of polyimide resin or polyethylene terephthalate resin. By providing the pattern in a pattern, for example, an electric circuit can be created.

The base coating containing the conductive polymer (A) or the like of the present invention may be applied to the entire surface of the base material, or may be applied to a part of the base material.
As a pattern printing method applied to a part of the substrate, for example, an inkjet printing method, an offset printing method, a gravure offset printing method, and a flexographic printing method can be applied. In addition, it can be applied to gravure printing, screen printing, dry offset printing, and pad printing. The printing method can be performed by a normal printing method using each printing machine.
In addition, as a means for applying the base coating to the entire surface of the base material, the above printing method may be used, the dip coating method, the brush coating method, the spin coating method, the casting method, the micro gravure coating method, the gravure coating method, the bar coating. The coating may be carried out by a method, a roll coating method, a wire bar coating method, a spray coating method, or a flow coating method.

In the present invention, the method for producing the coating film layer for base is preferably subjected to a heat treatment after coating the base paint containing the conductive polymer (A) or the like.
Examples of the heat treatment include a method of heating using a heater, a heating furnace, a hot plate, or the like. For example, the heating temperature is 85 ° C. or higher, preferably 90 ° C. or higher, 200 ° C. or lower, preferably 180 ° C. or lower, and treated for 2 to 180 minutes. It is preferable to process in the temperature range lower than Tg of the used base material.

Further, after applying a base paint containing the conductive polymer (A) or the like, a dedoping treatment may be performed. Examples of the dedoping treatment include reducing agents such as borohydride compounds such as sodium borohydride and potassium borohydride, alkylamine boranes such as dimethylamine borane, diethylamine borane, trimethylamine borane, triethylamine borane, and hydrazine. The method of processing and reducing with the solution containing or the method of processing with alkaline solutions, such as sodium hydroxide, is mentioned.
In addition, it is preferable to process with an alkaline solution from a viewpoint of operativity and economical efficiency. In particular, since the coating layer containing the conductive polymer (A) can be thinned, it is possible to achieve dedoping by mild 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.

Although the base material with the coating layer for plating base formed as described above is plated by an electroless plating method, the electroless plating method can be performed according to a generally known method. .
That is, after immersing the base material in a catalyst solution for attaching a catalytic metal such as palladium chloride, the substrate can be washed with water and immersed in an electroless plating bath to obtain a plated product.

The catalyst solution is a solution containing a noble metal (catalyst metal) having catalytic activity for electroless plating. Examples of the catalyst metal include palladium, gold, platinum, rhodium, etc. These metals may be simple substances or compounds. A palladium compound is preferable from the viewpoint of stability including a metal, and palladium chloride is particularly preferable among them.
Specific examples of the catalyst solution include 0.05% palladium chloride to 0.005% hydrochloric acid aqueous solution. 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.

The base material 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, 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. The obtained plated product is preferably cured for several hours or more, for example, 2 hours or more in a temperature range lower than the Tg of the used substrate.
The plated product can be further plated with the same or different metal on the formed electroless plating film by electrolytic plating. Moreover, a metal plating film may be formed on both surfaces of a base material.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited to these Examples.

[Production Example 1; Production of conductive polymer (A-1)]
A solution obtained by dissolving 200 mmol of ammonium peroxodisulfate and 1.0 g of sulfuric acid in 150 ml of a water / acetonitrile (volume ratio 1/1) mixture was cooled to 0 ° C. (internal temperature) with a bath using ethylene glycol, and the stirring power was 0 Under 0.7 kw / m ³ , a solution prepared by dissolving 200 mmol of 2-aminoanisole-4-sulfonic acid and 200 mmol of triethylamine in 150 ml of a water / acetonitrile (volume ratio 1/1) mixture was added dropwise at 200 mmol / hr.
After completion of the dropwise addition, cooling was maintained for 2 hours with stirring, and then the reaction product was filtered with a vacuum filter under cooling, washed with methyl alcohol and dried to obtain a crude polymer of conductive polymer.
20 g of the obtained crude polymer was dissolved in 400 ml of water, and 100 ml of an acidic cation exchange resin (manufactured by Organo Corporation, “Amberlite”) was packed in the column, and the crude polymer solution was added to the column at SV = 0.3. The cation exchange treatment was carried out at a flow rate of 1 to obtain a purified conductive polymer (A-1) solution.

[Example 1]
To the conductive polymer (A-1) solution prepared in Production Example 1, the water-soluble polymer (B-1) <Watersol S695 (aqueous melamine resin, solid content 65%), manufactured by DIC Corporation> was added to the conductive polymer ( A-1): The water-soluble polymer (B-1) was added so that the solid content ratio was 2: 1, and water was further mixed so that the final solid content was 3% to obtain a base coating material.
The paint prepared above was applied to a polyester film having a thickness of 100 μm by spin coating, dried at 120 ° C. for 10 minutes, and further heat-treated at 160 ° C. for 60 minutes to form a coating film. The thickness of the coating film after this heat treatment was 100 nm.
The film on which the coating film was formed was immersed in a palladium chloride solution at room temperature for 5 minutes and then washed with pure water. Next, when the film was immersed in an electroless copper plating bath, a polyester film on which copper plating was applied in about 10 minutes was obtained.

[Example 2]
In the conductive polymer (A-1) solution prepared in Production Example 1, the water-soluble polymer (B-2) <Kuraray Poval PVA-103 (polyvinyl alcohol), manufactured by Kuraray Co., Ltd.> was added to the conductive polymer (A-1). : Water-soluble polymer (B-2) was added so that the solid content ratio was 2: 1, and water was further mixed so that the final solid content was 3% to obtain a base coating material.
The paint prepared above was applied to a polyester film having a thickness of 100 μm by spin coating, dried at 120 ° C. for 10 minutes, and further heat-treated at 160 ° C. for 60 minutes to form a coating film. The thickness of the coating film after this heat treatment was 120 nm.
The film on which the coating film was formed was immersed in a palladium chloride solution at room temperature for 5 minutes and then washed with pure water. Next, when the film was immersed in an electroless copper plating bath, a polyester film on which copper plating was applied in about 10 minutes was obtained.

[Comparative Example 1]
In the same manner as in Example 1 except that the conductive polyaniline dispersion <ORMECON (solid content 2.5%), manufactured by Nissan Chemical Industries Ltd.> was used instead of the conductive polymer (A-1) solution. A base paint was obtained.
The paint prepared above was applied to a polyester film having a thickness of 100 μm by spin coating, dried at 120 ° C. for 10 minutes, and further heat-treated at 160 ° C. for 60 minutes to form a coating film. The thickness of the coating film after this heat treatment was 120 nm.
The film on which the coating film was formed was immersed in a palladium chloride solution at room temperature for 5 minutes and then washed with pure water. The film was then immersed in an electroless copper plating bath, but no plating was formed.

(Plating state evaluation method)
The state of the plating film was visually observed, and the substrate exposed area was measured. The evaluation results of Examples 1 and 2 and Comparative Example 1 are shown in Table 1.
The evaluation criteria were as follows.
○: Completely coated, no substrate exposure.
Δ: About 50% of substrate is exposed ×: 100% of substrate is exposed

(Adhesion evaluation method)
Based on JIS H8504, the peeling test was implemented by the tape test. The evaluation results of Examples 1 and 2 and Comparative Example 1 are shown in Table 1.
The evaluation criteria were as follows.
○: No peeling Δ: About 50% peeling ×: 100% peeling

In the plating base coatings of Examples 1 and 2, the coating layer for plating base was completely coated on the metal plating film by electroless plating. Moreover, the adhesiveness of the base material to which electroless plating was applied was also good.
On the other hand, in Comparative Example 1 using a conductive polymer having no acidic group, a metal plating film could not be formed by the electroless plating method without reduction treatment.
From the above, the present invention was able to form a metal plating film with good adhesion even by a simple electroless plating method without reduction treatment.

Claims (5)

  A base coating for forming a metal film on a substrate by electroless plating, wherein the base coating includes an aniline-based conductive polymer (A) having an acidic group. The ground coating material of Claim 1 whose aniline type conductive polymer (A) which has the said acidic group is a conductive polymer (A-1) which has a repeating unit represented by following General formula (1).

In formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxyl group, a nitro group or a halogen atom. Further, at least one of R ^{1 to} R ⁴ is an acidic group or a salt thereof.   The base paint according to claim 1 or 2, further comprising a water-soluble polymer (B).   The manufacturing method of the coating film layer for base | substrates which coats the base coating material as described in any one of Claims 1-3 on a base material, and heat-processes the coating film layer formed by this.   A method for producing a plated product, wherein a metal film is chemically plated from an electroless plating solution on the undercoat coating layer according to claim 4.