JP2003041375A - Catalyzer forming method for electroless plating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyzer forming method for electroless plating, which can form an electroless plating film superior in appearance and adhesion on a resin substrate, without employing expensive noble metals as catalytic metal. SOLUTION: The catalyzer forming method for the electroless plating is characterized by sequentially treating the resin substrate according to steps of (i)-(v): (i) a step of etching the resin substrate, (ii) a step of contacting the etched resin substrate with a solution containing a copper compound, (iii) a step of contacting the resin substrate treated in the above step (ii) with a solution containing an oxidizing agent, (iv) a step of contacting the resin substrate treated in the above step (iii) with a solution containing a nickel compound, and (v) a step of contacting the resin substrate treated in the above step (iv) with a solution containing a reducing agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for applying a catalyst for electroless plating and a method for producing an article on which an electroless plating film is formed.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a metal thin film on a resin base material by a wet method, a method of forming a metal thin film by an electroless plating method after adsorbing a catalyst for electroless plating on a resin is known. This is a common method.

In such a method, palladium is widely used as a catalyst for electroless plating because it exhibits a very high catalytic activity. Usually, sensitizer activator method, catalyst accelerator method, etc. The method of applying a catalyst in which the Sn / Pd mixed catalyst is adsorbed on the resin is adopted by the method of.

However, in recent years, metallic palladium has been
The demand for catalysts for automobile exhaust gas has increased and the price has soared rapidly, and the demand for catalysts for electroless plating other than palladium compounds has increased.

There have been many studies and reports on electroless plating catalysts replacing palladium, but most of them use expensive precious metals such as Pt, Au, Ag and Ru. Therefore, it is desired to develop a method capable of forming a good electroless plating film using a cheaper catalyst material.

[0006]

The main object of the present invention is to:
By providing a catalyst application method for electroless plating capable of forming an electroless plating film having a good appearance and excellent adhesion on a resin substrate without using expensive precious metals as a catalyst metal. is there.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has conducted an etching treatment on a resin base material as an object to be plated, and then an aqueous solution containing a copper compound, By sequentially contacting an aqueous solution containing an oxidizing agent, an aqueous solution containing a nickel compound, and an aqueous solution containing a reducing agent, it is possible to impart excellent catalytic activity to a resin substrate without using a noble metal compound as a catalytic substance. It was found that it is possible to form an electroless plating film having good appearance and excellent adhesion, and thus completed the present invention.

That is, the present invention provides the following method for applying a catalyst for electroless plating and a method for producing an article having an electroless plating film formed thereon. 1. A method for applying a catalyst for electroless plating, which comprises sequentially treating a resin substrate according to the following steps (i) to (v): (i) a step of etching a resin substrate, (ii) an etched resin A step of contacting the base material with an aqueous solution containing a copper compound, (iii) a step of contacting the resin base material treated in the step (ii) with an aqueous solution containing an oxidizing agent,
(Iv) contacting the resin base material treated in the above step (iii) with an aqueous solution containing a nickel compound, (v) contacting the resin base material treated in the above step (iv) with an aqueous solution containing a reducing agent Process. 2. 2. The method for applying a catalyst for electroless plating according to item 1, wherein the resin constituting the resin substrate is a resin containing acrylonitrile as a constituent monomer component. 3. The aqueous solution containing a copper compound is an aqueous solution containing a water-soluble copper compound in an amount of 0.001 to 2 mol / l as the amount of copper metal, and the aqueous solution containing an oxidizing agent is sodium peroxodisulfate, potassium peroxodisulfate, or peroxide. An aqueous solution containing 0.001 to 2 mol / l of at least one oxidizing agent selected from hydrogen water, perchloric acid, nitric acid and sulfuric acid, wherein the aqueous solution containing a nickel compound has a water-soluble nickel compound as the amount of nickel metal. 0.001-2m
The aqueous solution containing a reducing agent contains 0.001 to 0 of at least one reducing agent selected from borohydride compounds, amineboranes, hypophosphite, aldehydes and hydrazine. Item 3. The method for applying a catalyst for electroless plating according to Item 1 or 2, which is an aqueous solution containing 0.5 mol / l. 4. A method for producing an article having an electroless plating film, which comprises applying an electroless plating catalyst to a resin substrate by the method according to any one of Items 1 to 3 and then performing an electroless plating treatment.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the method of the present invention, as the resin base material to be treated, molded articles made of various thermosetting resins, thermoplastic resins and the like which have been conventionally subjected to plating can be used. . In addition, a film made of the above resin may be formed on the surface of a base material made of ceramics, glass, metal or the like, or a composite in which a glass fiber reinforcing material or the like is interposed between the resins. Good. Further, it may be a composite containing two or more kinds of resins.

Among these resin base materials, a resin base material using a resin containing acrylonitrile as a constituent monomer component is preferably used in the present invention because it can be easily etched and can impart good catalytic activity. be able to.

Specific examples of the resin containing acrylonitrile as a constituent monomer component include acrylonitrile-butadiene-styrene resin (ABS resin) and polycarbonate-acrylonitrile-butadiene-styrene resin (P
C-ABS resin), acrylonitrile / acrylic / styrene resin (AAS resin), acrylonitrile / ethylene propylene rubber / styrene resin (AES resin), and the like.

The content of acrylonitrile in these resins is not particularly limited, and any conventionally used acrylonitrile-containing resin can be used. In particular, for ABS resins, the ratio of acrylonitrile to the total constituent monomer components is usually 10 to 40.
The amount of the acrylonitrile is preferably about 5 to 20% by weight with respect to the entire constituent monomer components for the PC-ABS resin.

(I) Etching Treatment In the method of the present invention, first, if necessary, pretreatment such as degreasing is performed according to a conventional method, and then the resin substrate is subjected to etching treatment.

The specific etching treatment method is not particularly limited, and a conventionally used etching treatment method may be appropriately adopted according to the type of resin to be treated.

For example, in the method of etching using an etching solution, a conventionally used etching solution may be appropriately selected and used as the etching processing solution depending on the type of resin to be processed. it can. As such an etching liquid, a chromic acid-sulfuric acid etching liquid is representative, and other phosphoric acid-chromic acid-sulfuric acid etching liquid, phosphoric acid-perchloric acid-potassium permanganate etching liquid, permanganese A potassium acid-phosphoric acid-based etching solution or the like can also be used.

As the chromic acid-sulfuric acid etching solution, an aqueous solution containing about 100 to 500 g / l of CrO ₃ and about 100 to 500 g / l of 98% sulfuric acid can be usually used.

Other etching solutions can be used as they are in the commonly used concentration range. For example, for phosphoric acid-perchloric acid-permanganate etching solution, 89% phosphoric acid is used in an amount of 450 to 650 ml /. It is possible to use an aqueous solution containing about 1 liter, 60% perchloric acid of about 30 to 100 ml / l, and potassium permanganate of about 3 to 7 g / l.

The etching treatment method using an etching solution is not particularly limited, and a known etching method can be adopted according to the resin base material used. Usually, the resin base material may be immersed in the etching liquid, but other methods such as spraying the etching liquid onto the surface of the resin base material can also be used.

The etching treatment conditions when using the etching liquid are not particularly limited, and the liquid temperature of the etching liquid, the etching time and the like can be appropriately adjusted. In the method of the present invention, the temperature of the etching solution may be adjusted according to the heat-resistant temperature of the resin base material to be treated, the type of the etching solution, etc., but is usually preferably about 50 ° C. or higher. The upper limit of the liquid temperature of the etching liquid may be set in consideration of the heat resistant temperature of the resin used. For example, when an ABS resin is included as the resin constituting the resin base material, it is preferable to set the upper limit of the liquid temperature to about 80 ° C. Similarly, when a PC-ABS resin is included, it is preferable to set the upper limit of the liquid temperature to about 100 ° C. Usually, the liquid temperature may be about 60 to 70 ° C.

The etching time is preferably about 1 to 20 minutes, more preferably about 5 to 10 minutes. When the etching time is long, excessive etching tends to increase the surface roughness. Increasing the surface roughness is effective in improving the adhesion of the plating film, but may reduce the gloss of the plating film.

Further, an etching method generally called dry etching, such as irradiation with ozone, ultraviolet rays or excimer laser, can be adopted.

It is considered that the above-mentioned etching treatment roughens the surface of the object to be plated, improves the adhesiveness of electroless plating, and forms hydrophilic functional groups such as carboxyl groups and carbonyl groups. To be (Ii) Treatment with aqueous solution containing copper compound: After the etching treatment, the resin base material is brought into contact with the aqueous solution containing copper compound. Due to this, it is considered that the copper compound is adsorbed or bonded to the surface of the resin base material.

The copper compound may be any water-soluble compound, and specific examples thereof include copper sulfate, copper nitrate, copper chloride, copper acetate, and copper formate. The copper compound is
They can be used alone or in combination of two or more.

The concentration of the copper compound in the aqueous solution containing the copper compound is 0.001 to 2 mo as the copper metal concentration.
It is preferably about 1 / l, and is 0.01 to 0.5 m.
More preferably, it is about ol / l.

The pH of the aqueous solution containing the copper compound is not particularly limited as long as it can stably dissolve the copper compound contained in the aqueous solution. Generally, the pH is preferably about 4 or higher, more preferably about 5 or higher. preferable. In addition, a known complexing agent may be added to suppress the formation of precipitates such as metal hydroxides in the aqueous solution.

The method of bringing the object to be plated into contact with the aqueous solution containing the copper compound is not particularly limited. Generally, the object to be plated may be dipped in the treatment solution, but in addition, the treatment solution is sprayed. A method etc. can also be adopted.

The treatment conditions with the aqueous solution containing the copper compound are not particularly limited, and the liquid temperature, the treatment time and the like can be selected from a wide range, but the treatment liquid temperature is usually about 30 to 80 ° C. Is preferably 40 to 60
It is more preferable to set the temperature to about ° C. By increasing the treatment temperature within such a liquid temperature range, it becomes possible to increase the adsorption or binding amount of the copper compound and improve the depositability of electroless plating.

The processing time is preferably about 1 to 10 minutes, more preferably about 2 to 5 minutes. (Iii) Treatment with aqueous solution containing oxidizing agent: After treatment with aqueous solution containing copper compound, the resin substrate is brought into contact with the aqueous solution containing oxidizing agent. As a result, oxidation of the copper compound adsorbed or bonded to the surface of the resin base material proceeds.

As the oxidizing agent, a water-soluble compound having an oxidizing action can be used, and specific examples thereof include sodium peroxodisulfate, potassium peroxodisulfate,
Hydrogen peroxide water, perchloric acid, nitric acid, sulfuric acid or the like can be used. The oxidizing agents may be used alone or in combination of two or more.

The concentration of the oxidizing agent is 0.001 to 2 mol /
It is preferably about 1 and 0.01 to 1 mol / l
It is more preferable to adjust the degree.

The pH of the oxidizing agent-containing aqueous solution is not particularly limited, but a pH range in which the copper compound existing on the surface of the object to be plated is not dissolved is preferable, usually about pH 3 or more, preferably about pH 4 to 7. Is more preferable.

There is no particular limitation on the method of bringing the object to be plated into contact with the aqueous solution containing the oxidizing agent, and generally,
The object to be plated may be immersed in the treatment liquid, but other methods such as spraying the treatment liquid can also be adopted.

The treatment conditions with the aqueous solution containing the oxidizing agent are not particularly limited, and the liquid temperature, the treatment time and the like can be selected from a wide range, but usually the treatment liquid temperature is about 10 to 50 ° C. It is preferable to do
It is more preferable to adjust the degree. Processing time is 1-10
It may be about 1 minute, preferably about 2 to 5 minutes. (Iv) Treatment with nickel-containing aqueous solution: After the treatment with the oxidizing agent-containing aqueous solution, the resin base material is brought into contact with the aqueous solution containing the nickel compound.

The nickel compound is not particularly limited as long as it is a water-soluble compound, and specific examples thereof include nickel sulfate, nickel chloride, nickel nitrate, nickel acetate, nickel sulfamate and the like. The nickel compounds may be used alone or in combination of two or more.

The concentration of the nickel compound in the aqueous solution containing the nickel compound is defined as the nickel metal concentration.
It is preferably about 0.001 to 2 mol / l,
More preferably, it is about 0.05 to 0.5 mol / l.

The pH of the aqueous solution containing the nickel compound is not particularly limited as long as it can stably dissolve the nickel compound contained in the aqueous solution.
It may be about 9 and preferably about 6-8. In addition, a known complexing agent may be added to suppress the formation of precipitates such as metal hydroxides in the aqueous solution.

There is no particular limitation on the method of bringing the object to be plated into contact with the aqueous solution containing the nickel compound. Generally, the object to be plated may be immersed in the treatment solution, but otherwise, the treatment solution is sprayed. A method etc. can also be adopted.

The treatment conditions with the aqueous solution containing the nickel compound are not particularly limited, and the liquid temperature, the treatment time and the like can be selected from a wide range, but usually the treatment liquid temperature is about 30 to 80 ° C. Preferably 40
It is more preferable to set the temperature to about 60 ° C. By raising the treatment temperature within such a liquid temperature range, it becomes possible to increase the adsorption or binding amount of the nickel compound and improve the depositability of electroless plating.

The processing time may be about 1 to 10 minutes, preferably about 2 to 5 minutes. (V) Treatment with an aqueous solution containing a reducing agent : After the treatment with an aqueous solution containing a nickel compound, an activation treatment is performed by bringing the resin base material into contact with an aqueous solution containing a reducing agent.

As the reducing agent, any water-soluble compound having a reducing action can be used without particular limitation. Specific examples of the reducing agent include dimethylamine borane (DMA
B), amine boranes such as trimethylamine borane (TMAB); borohydride compounds such as potassium borohydride and sodium borohydride; sodium hypophosphite,
Examples include hypophosphite such as potassium hypophosphite; aldehydes such as formalin; and hydrazine.
The reducing agents may be used alone or in combination of two or more.

The concentration of the reducing agent is 0.001 to 0.5 mo.
It is preferably about 1 / l, and is 0.01 to 0.2 m.
More preferably, it is about ol / l. The pH of this aqueous solution is not particularly limited, and may be appropriately set within the range that the reducing performance is good and the stability of the reducing agent is not hindered, depending on the type of the reducing agent used. Usually, it is preferable that the pH is about 7 or higher.

There is no particular limitation on the method of bringing the object to be plated into contact with the aqueous solution containing the reducing agent, and in general,
The object to be plated may be immersed in the treatment liquid, but other methods such as spraying the treatment liquid can also be adopted.

The treatment conditions with the aqueous solution containing a reducing agent are not particularly limited, and the liquid temperature, the treatment time and the like can be selected from a wide range, but particularly, the treatment liquid temperature is about 30 to 90 ° C. Is preferably 40 to 80
It is more preferable to set the temperature to about ° C. Processing time is 1-2
It is preferably about 0 minutes, more preferably about 3 to 10 minutes.

After applying the catalyst by the above method, electroless plating can be performed to form an electroless plating film.

The method for applying a catalyst for electroless plating of the present invention is as follows:
It can be applied as a catalyst application method for various electroless platings, and examples thereof include electroless copper plating solutions, electroless Ni-P plating solutions, and electroless Ni-B plating solutions.

In the electroless plating treatment, the treatment conditions such as the temperature of the plating solution and the plating time may be appropriately determined according to a conventional method depending on the type of resin base material and the type of plating solution. Further, after forming the electroless plating film, various electroplating can be performed according to a conventional method, if necessary.

In the method of the present invention, in general, before each treatment, in order to prevent the treatment liquid from being brought in from the previous step,
Wash with water.

[0048]

According to the method of applying a catalyst of the present invention, various resin substrates can be provided with excellent catalytic activity for electroless plating without using an expensive noble metal compound as a catalyst substance.

The electroless plating film formed by the method for applying a catalyst of the present invention becomes a uniform plating film having excellent adhesion.

[0050]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 ABS resin molded product (manufactured by Mitsubishi Rayon Co., Ltd., 3001)
M, size 100 × 50 × 3 mm) as the object to be plated,
Add 400 g / l of CrO ₃ and ₄ % of 98% H ₂ SO ₄ to this.
An etching treatment was carried out by immersing in a chromic acid etching solution containing 00 g / l at 70 ° C. for 10 minutes.

After washing with water, 5
It was immersed at 0 ° C for 5 minutes, washed with water, and then immersed at 25 ° C for 3 minutes in an aqueous solution containing an oxidizing agent. Then, after washing with water, it is immersed in an aqueous solution containing a nickel compound at 50 ° C. for 5 minutes, and after washing with water, 60 ° C. in an aqueous solution containing a reducing agent.
And soaked for 5 minutes.

Thereafter, 60 to-be-plated objects were placed in an electroless nickel plating solution (TSP-48 manufactured by Okuno Chemical Industries Co., Ltd.).
After dipping at 10 ° C. for 10 minutes to form an electroless nickel plating film, the appearance of the plating film was evaluated and the adhesion strength was measured. The results are shown in Table 1 below.

The appearance of the plating film was judged by visual observation. Adhesive strength is JIS H-8630
According to the above, an electrolytic copper plating film of about 60 μm was formed on the electroless plating film, dried at 80 ° C. for 2 hours, and then the peel strength was measured.

The types and concentrations of the copper compound, oxidizing agent, nickel compound and reducing agent used in the above method are shown in Table 1 below.

[0056]

[Table 1]

Example 2 After applying a catalyst for electroless plating to an ABS molded article by the same method as in Example 1, it was plated in an electroless copper plating solution (Kappa T manufactured by Okuno Chemical Industries Co., Ltd.). Things at 60 ℃
To form an electroless copper plating film.

Thereafter, in the same manner as in Example 1, the appearance of the plating film was evaluated and the adhesion strength was measured.

Table 2 below shows the types and concentrations of the compounds used in the above method, the appearance evaluation of the plating film and the measurement results of the adhesion strength.

[0060]

[Table 2]

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4K022 AA13 AA14 AA21 BA08 BA14                       CA02 CA05 CA06 CA14 CA15                       CA17 CA19 CA23 DA01

Claims (4)

[Claims] 1. A method for applying a catalyst for electroless plating, which comprises sequentially treating a resin substrate according to the following steps (i) to (v): (i) a step of etching a resin substrate, (ii) ) Contacting the etched resin base material with an aqueous solution containing a copper compound, (iii) contacting the resin base material treated in step (ii) with an aqueous solution containing an oxidant,
(Iv) contacting the resin base material treated in the above step (iii) with an aqueous solution containing a nickel compound, (v) contacting the resin base material treated in the above step (iv) with an aqueous solution containing a reducing agent Process. 2. The resin constituting the resin substrate is a resin containing acrylonitrile as a constituent monomer component.
The method for applying a catalyst for electroless plating according to item 4. 3. An aqueous solution containing a copper compound is an aqueous solution containing a water-soluble copper compound in an amount of 0.001 to 2 mol / l as the amount of copper metal, and an aqueous solution containing an oxidizer is sodium peroxodisulfate or peroxodioxide. An aqueous solution containing 0.001 to 2 mol / l of at least one oxidizing agent selected from potassium sulfate, aqueous hydrogen peroxide, perchloric acid, nitric acid and sulfuric acid, wherein the aqueous solution containing a nickel compound is a water-soluble nickel compound. 0.001 as nickel metal amount
Is an aqueous solution containing ~ 2 mol / l, and the aqueous solution containing a reducing agent contains at least one reducing agent selected from borohydride compounds, amineboranes, hypophosphite, aldehydes and hydrazine in an amount of 0.001- 0.5 mol /
The method for applying a catalyst for electroless plating according to claim 1 or 2, which is an aqueous solution containing l. 4. An article having an electroless plating film formed by applying an electroless plating catalyst to a resin base material by the method according to claim 1, and then performing an electroless plating treatment. Production method.