JPH02277778A - Production of structure made of synthetic resin coated with metal - Google Patents

Abstract

PURPOSE:To reduce pollution-related problems and to form a tightly adhered metallic film by sticking iodine, iodide, bromine and/or bromide on the surface to be plated and thereafter bringing this surface into contact with inorganic peroxide and plating the surface. CONSTITUTION:When a base material with halides stuck thereto is brought into contact with inorganic peroxide, the halides violently decompose the inorganic peroxide and nascent oxygen is produced. The surface of the base material is oxidized and decomposed and thereby the extremely fine unevennesses are formed on the surface of the base material. Activation is performed for electroless plating and adsorptivity of a chemical plating catalyst is enhanced. A metallic film excellent in uniformity and adhesive properties can be formed by electroless plating. Build-up amount and/or adhesive force of the halides are enhanced by performing swelling treatment with liquid contg. a solvent of synthetic resin before sticking treatment of the halides is performed or at the same time therefor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of metal coating the surface of a synthetic resin structure,
More specifically, when forming a metal coating on the surface of a synthetic resin structure by electroless plating, the surface to be plated is treated with an inorganic peroxide prior to electroless plating to ensure uniformity and excellent adhesion. The present invention relates to a method for forming a metal coating.

Generally, in order to perform electroless plating on the surface of a non-conductive structure, it is common to immerse the non-conductive structure, which has undergone pre-treatments such as degreasing, catalyst application, and activation, in an electroless plating bath. At this time, mechanical etching, chemical etching, low-temperature plasma etching, etc. are used to improve the wetting of the substrate surface and improve the adsorption and adhesion ability of the catalyst, or to improve the adhesion between the substrate and metal. It is also often used in combination with surface geography.

Currently, synthetic resins that are industrially targeted for electroless plating include ABS resins, polypropylene resins, polyamide resins, polycarbonate resins, and the like. This is because these base materials are easily chemically etched and have relatively good adhesion during electroless plating.

On the other hand, examples of resins that are difficult to plate include polyester resins, vinyl chloride resins, vinylidene chloride resins, and the like.

Regarding chemical etching of these resins, for example, Japanese Patent Publication No. 47-19600 describes that prior to plating resins such as polyamide, polyester, polyvinyl chloride, polyvinylidene chloride, and polyolefin, an organic solvent suitable for each resin is used. For example, for vinyl chloride resins, use ethyl acetate, acetone, benzene, trichlene, etc., for polyester resins, use m-cresol, a 10-20% aqueous solution of 0-phenol, and for polypropylene, use Mix 10 to 20% of an organic solvent such as decalin or tetralin to a 5% aqueous solution of caustic soda, and further add a surfactant of 2 to log/12 to form an emulsion. Swelling treatment is performed at 50 to 60°C in a bath or the like. , then 2-5% potassium dichromate in 50-60% sulfuric acid aqueous solution.
A method is disclosed in which etching is performed for 1 to 2 minutes at 50 to 70 DEG C. in a bath containing 100 g/12 g/12, followed by electroless plating.

However, the chemical etching agent used after swelling the resin with this method, a mixture of sulfuric acid and potassium dichromate, has strong oxidizing power, which can cause problems such as resin defects and a decrease in physical strength. This may occur.

Moreover, wastewater containing dissolved chromic acid is subject to strict pollution regulations, and the wastewater treatment method is complicated, and furthermore, there are many difficulties in the treatment of chromium-containing sludge that has been collected by precipitation.

On the other hand, one way to improve the adhesion of electroless plated metal films is to add fine irregularities to the surface of synthetic resin structures, but sandblasting, which is often used on plastic molded products, etc. The mechanical roughening method causes severe damage to structures such as fibers, and cannot be applied to structures with complex shapes, making it practically unusable.

In addition, JP-A-60-181362 discloses an improved method for chemically plating polyester fibers, in which polyester fibers containing a compound having a sulfonic acid group and/or a metal sulfonate group are immersed and/or passed through an alkaline bath. By doing so, a weight loss treatment of 8 to 30% by weight is performed,
A method is disclosed in which a metal sulfonate group is exposed on the fiber surface, and then a catalyst is applied and an activation treatment is performed to form an electroless plated metal film. However, in this method, in order to perform melt spinning with a compound having a metal sulfonate group coexisting in the polyester spinning raw material, special preparation is required from the spinning raw material stage. However, there are disadvantages such as abrasion of the spinning nozzle or yarn breakage during spinning.

Furthermore, JP-A No. 48-54299 describes a method for electroless plating of polyamide fibers, and this method includes the following steps:
An alcohol solution of N-alkoxymethyl nylon is attached to nylon fibers without physically or chemically etching the polyamide fibers, and then rapidly dried at a temperature higher than the boiling point of the alcohol as a solvent,
In this method, the alcohol quickly vaporizes during drying, forms fine bubbles, and separates from the surface of the N-alkoxymethyl nylon, thereby firmly adhering the N-alkoxymethyl nylon to the nylon fibers. The surface of N-alkoxymethyl nylon becomes finely uneven due to vaporization and dissipation of alcohol, so there is no need for chemical etching with a mixture of dichromic acid and sulfuric acid, and a metal plating layer is formed by direct electroless plating. It becomes possible to do so.

However, this method requires the use of alcohol as a solvent for N-alkoxymethyl nylon, and also requires a step of rapidly heating and vaporizing it above the boiling point of the alcohol, which poses a risk of fire and an environmentally friendly environment due to organic solvents. What are the drawbacks such as pollution?

Furthermore, there is a problem in that this method is difficult to apply to housings and other large and complex-shaped objects.

Furthermore, according to Japanese Patent Publication No. 63-35751, at least one surface of a fiber base fabric is treated with low-temperature plasma, and then ion blasting is applied to the treated surface to form a metal film on the surface of the fiber base fabric. A method is disclosed in which the low temperature plasma treatment is performed at a temperature of 0.01-1
Under an extremely low pressure of 0 Torr, using a gas that does not have plasma polymerizability, such as helium, neon, argon, nitrogen, oxygen, etc., these gases are dissociated and ionized by high voltage to create a sputtering effect on the surface of the fiber base fabric. It is described that the fiber surface is modified by the high energy of plasma, and its affinity with metal is improved, and a metal film that adheres tightly is formed by ion blasting. However, the above-mentioned low-temperature plasma processing equipment is expensive, and since the atoms dissociated and ionized by high voltage travel in a straight line, the panthering effect is exerted only on the surface, and the back surface or areas shaded by overlapping fibers are hardly affected. No treatment effect was observed. Therefore, in order to perform low-temperature plasma treatment on the front and back sides of a textile base fabric, it is necessary to treat the front and back sides separately, that is, the same textile base fabric must be printed through the same process on the front and back sides. There are economic disadvantages. In addition, for large continuous areas such as fiber base fabrics,
It is extremely difficult to uniformly apply the sputtering effect of dissociated and ionized atoms, and when applied to vinyl chloride resins and vinylidene chloride resins, some of the constituent molecules decompose and generate chlorine gas. There are drawbacks.

The main purpose of the present invention is to activate the surface of a synthetic resin structure to be electrolessly plated under simple and mild conditions in order to eliminate the above-mentioned drawbacks in electroless plating of a synthetic resin structure. It is an object of the present invention to provide a method for forming a uniform and firmly adherent metal coating without causing a decrease in physical strength or damage to a synthetic resin structure.

Thus, according to the present invention, in the method of forming a metal film on the surface of a synthetic resin structure by electroless plating,
Prior to electroless plating, iodine, iodide, bromine and/or bromide is attached to the surface of the synthetic resin structure on which the metal coating is to be formed, and then the surface of the structure is coated with an inorganic peroxide. Provided is a method for coating a surface of a synthetic resin structure with metal, the method comprising contacting the surface of a synthetic resin structure with metal.

Synthetic resin structures to be treated by the present invention include fiber structures such as threads (filaments, fiber yarns, etc.), cotton-like materials, tows, woven fabrics, knitted fabrics, non-woven fabrics, rod-shaped structures, plates, and films. This includes conditions such as The material of such a structure is not particularly limited, and may be made of various synthetic resins such as polyamide, polyolefin, polyester, vinyl chloride, vinylidene chloride, polyacrylic, polycarbonate, polyoxymethylene, and ABS. Can be configured.

When performing electroless plating on the surface of such a synthetic resin structure (hereinafter referred to as a base material), the method of the present invention applies iodine, iodide, The feature is that the surface of the substrate is activated by contacting the surface of the substrate with an inorganic peroxide after attaching bromine and/or bromide (hereinafter referred to as a halogen compound for convenience).

When carrying out such an activation treatment on a base material, prior to said treatment, pretreatments that are usually carried out in electroless plating of synthetic resin base materials, such as degreasing, scouring, etc., can be carried out as appropriate. For example, the base material can be degreased and refined by immersing it in an aqueous solution containing a suitable surfactant under heating.

According to the present invention, a halogen compound is first attached to the surface of the base material which has been properly prepared in this manner. Iodine, iodide, bromine and/or bromide are used as the halogen compound. Iodides include, for example, potassium iodide, sodium iodide, lithium iodide, and the like, and bromides include, for example, potassium bromide, sodium bromide, lithium bromide, and the like. Iodine is preferably used in combination with an iodide such as potassium iodide, and bromine can be used alone or in combination with a bromide such as potassium bromide.

These halogen compounds can be attached to the surface of the substrate by immersing it in a solution containing the halogen compound and then drying it. Generally, an aqueous solution is used as the solution, but depending on the type of the halogen compound and/or the base material, an organic solvent solution such as alcohol, ethylene glycol, or acetone, or a water-organic solvent mixed solution may also be used. It is also possible to use materials that have the property of swelling the synthetic resin of the base material.

The concentration of the catalyst compound in the solution is not particularly limited, but is generally 0. O1~50g/Q.

Preferably, it is within the range of 0.05 to 20 g/Q.

Furthermore, by containing a cationic, nonionic, amphoteric, etc. surfactant in the solution as necessary,
The wettability of the surface of the base material may be improved.

The temperature during treatment with a solution containing a halogen compound is usually around room temperature (approximately 15 to approximately 40°C), but in some cases the treatment may be performed under heating up to approximately 40°C; The treatment time can be approximately 20 to 180 minutes.

By removing the solvent from the base material to which the solution containing the halogen compound has been applied by a conventional method, the halogen compound can be deposited and deposited on the surface of the base material.

According to the present invention, the amount and/or adhesion force of the halogen compound can be improved by subjecting the surface of the base material to a swelling treatment, if necessary, before or at the same time as performing the above-mentioned halogen compound attachment treatment. can. Such swelling treatment involves treating the surface of the base material to be plated with a liquid containing a solvent (good solvent) for the synthetic resin constituting the base material, such as dipping treatment, spraying treatment, transfer treatment, etc. This can be done by Specific examples of such liquids include formic acid aqueous solution when the base material is a polyamide resin, m-cresol, and m-cresol when the base material is a polyester resin.
When the 10 to 20% aqueous solution of 0-cresol or phenol is a polycarbonate-based resin, a dimethylformamide aqueous solution is preferred, and when it is a vinyl chloride-based or vinylidene chloride-based resin, or ABS, a tetrahydrofuran aqueous solution is preferred. I can give an example.

The above swelling treatment is usually suitably carried out at a temperature of room temperature to about 60°C.

The substrate, to which the catalyst compound has been deposited as described above, is then contacted with an inorganic peroxide. Examples of inorganic peroxides include hydrogen peroxide, potassium persulfate, sodium persulfate,
Examples include ammonium persulfate, sodium perborate, and sodium percarbonate.

These are usually used in the form of an aqueous solution, but it is generally preferable to use them in combination with an acid such as sulfuric acid or an alkali such as caustic soda or caustic potash.

The concentration of inorganic peroxide in the aqueous solution is not strictly limited, but is generally t-io.

g/Q, preferably within the range of 5 to 50 g/Q. In addition, when sulfuric acid is used in combination, its concentration is usually 1 to 250 g/Q, especially 5 to 200 g/+
In addition, when an alkali is used in combination, the concentration can be generally within the range of 1 to 150 g/ff, preferably 5 to 100 g/ff.

The base material to which the halogen compound is attached can be brought into contact with the inorganic peroxide, for example, by immersing the base material in an aqueous solution containing the inorganic peroxide at the above concentration. The temperature during immersion can generally be from room temperature to about 80°C, preferably from room temperature to about 60°C, and the immersion time is suitably about 20 to about 180 minutes depending on the temperature.

As a result, halogen compounds such as iodine or bromine adhering to the surface of the substrate violently decompose inorganic peroxides such as hydrogen peroxide as shown in the following reaction formula: % formula % to generate oxygen as a generator. , so-called chemical etching occurs in which the surface of the base material is oxidized and decomposed to form extremely fine irregularities on the surface of the base material, and the surface of the base material is activated for electroless plating. As a result, the substrate activated according to the method of the present invention has improved adsorption of chemical plating catalysts, and can form a metal coating with excellent uniformity and adhesion by electroless (chemical) plating. .

Electroless plating on the surface of the substrate activated as described above is performed by a method known per se, for example, a method described in documents such as "Surface Treatment Technology Overview" (published by Industrial Technology Service Center). I can do it. For example, electroless copper plating can be performed by using a reducing agent such as formaldehyde to deposit copper ions in a solution as metal on the surface of the plated object.

The main reaction of electroless copper plating deposition is Cu2″ in the plating solution.
When the complex of `` is expressed as (Cu-chelating agent), it is an autocatalytic reaction expressed by the following formula.

[Cu-chelate] +2HCHO+40H--Cu'
+2HCOO-+H2↑+2H20+chelating agent Hypophosphite is the most common reducing agent for electroless nickel plating.

The basic reaction formula for electroless nickel plating is as follows (
acid bath).

Catalyst (Pd) N i ''+H2PO2-+H2O N i' 1 H2PO3-+2H'' Next, the method of the present invention will be described in more detail with reference to Examples.

Example 1 A polycarbonate plate (commercially available product: thickness 2 mm) was heat-treated at 145°C for 3 minutes, and then a nonionic surfactant (X
After degreasing and scouring in a 5 g/Q aqueous solution at 50° C. for 30 minutes, the sample was washed with water and dried.

Then, add 30'O to 85% dimethylformamide aqueous solution.
After soaking for 60 minutes and washing with water, soak in a bromine log/Q aqueous solution of 25
It was soaked at °C for 60 minutes and washed with water.

Next, caustic soda 1 Og/Q and hydrogen peroxide 20g/
It was immersed in an aqueous solution of the mixture of Q at 45°C for 180 minutes and washed with water.

Furthermore, it was immersed in an aqueous solution containing 10 g/Q of bromine at 25°C for 60 minutes, washed with water, then immersed in a mixed aqueous solution of 50 g/Q of sulfuric acid and 30 g/Q of hydrogen peroxide at 45°C for 60 minutes, washed with water, and dried.

A mixed solution of palladium chloride and tin chloride (
Catalyst 0Pc80; Okuno Pharmaceutical) 50mQ and hydrochloric acid 1
A mixed solution of 60 mQ and 790 mQ of water was prepared.

The treated polycarbonate plate was immersed in this solution for 2 minutes at 25°C, washed with water, and then immersed in a mixed solution of 50 ml of sulfuric acid and 950 m of water for 3 minutes at 45°C for activation, so that palladium chloride was applied to the surface of the resin structure. It was fixed to.

After that, I washed it with water and applied electroless nickel plating.

The conditions for electroless nickel plating are as follows.

<Nickel plating bath composition> Nickel hypophosphite 28g/Q boric acid
12//ammonium sulfate
3 Sodium acetate 5
ttpH: 6.0 As a result of immersion in a nickel plating bath at 33° C. for 6 minutes, a uniform mirror-like nickel film was formed. The amount of nickel plating deposited was 28% OWf, and the surface electrical resistance was 1.5Ω/
The resin structure had good conductivity at cm.

Comparative Example 1 Polycarbonate (commercial product: thickness 2 mm) was heat treated at 145°C for 3 minutes, and then degreased and degreased for 3 minutes at 50°C in an aqueous solution of 5g/12 of a nonionic surfactant (XO-7; manufactured by Tasei Kagaku). After scouring, it was washed with water and dried.

Then, add 85% dimethylformamide aqueous solution to 30°C.
It was soaked in water for 60 minutes and washed with water.

Next, caustic soda log/Q and hydrogen peroxide 20g/
It was immersed in an aqueous solution of the mixture of Q at 45°C for 180 minutes and washed with water.

Furthermore, it was immersed in a mixed aqueous solution of 5 g/Q of sulfuric acid and 30 g/Q of hydrogen peroxide at 45° C. for 60 minutes, washed with water, and dried.

Thereafter, electroless nickel plating was performed under the same conditions as in Example 1, and a uniform plating film was obtained.

The amount of nickel plating film was 28% OWf, and the surface electrical resistance was 1.5 Ω/cm, indicating a good conductive metallized resin structure.

Comparative Example 1 shows the adhesion strength of the metal film of the structure obtained in Example 1.
The results of comparing the adhesion strength of the metal film of the structure obtained in the above are shown in Table 1 below, and the adhesion strength of the structure obtained by the method of the present invention was higher.

<Measurement method> Peeling test method: Use a needle on the plated surface to measure length 1 at 1 mm intervals.
10 parallel horizontal lines of 0 mm are drawn, and then parallel vertical lines of 10 mm in length are drawn perpendicularly to the horizontal lines at 1 mm intervals to cut in a grid pattern. On top of this, commercially available cellophane tape is applied and peeled off at once, and the number of stitches that are peeled off along with the cellophane tape is read.

Table 1 Example 2 Sides A and B of a polyester magic fastener (manufactured by Kuraray) were treated in an aqueous solution of 3 g/(2) of a nonionic surfactant (WS-20; Daiichi Kogyo Seiyaku) at 50°C for 6 minutes. Degreasing/
After scouring, it was washed with water and dried.

Next, it was immersed in a 30% formic acid aqueous solution at 25°C for 30 minutes, and after washing with water, 15 g/ff of iodine and 25 g/f of potassium iodide were added.
It was immersed in an aqueous solution of the mixture of f at 25°C for 60 minutes and washed with water.

Next, it was immersed in an aqueous solution of a mixture of 100 g/Q of sulfuric acid and 20 g/Q of sodium percarbonate at 45°C for 180 minutes, washed with water and dried, and then electroless nickel plating was performed under the same conditions as in Example 1. A uniform plating film was obtained.

The amount of nickel plating film is 25% OWf, the surface electrical resistance is 1
．． The conductivity was good at 5Ω/cm.

Comparative Example 2 The same polyester Magic 7 Asnar (manufactured by Kuraray) as used in Example 2 was mixed with a nonionic surfactant (WS-2).
After degreasing and scouring in a 3 g/Q aqueous solution at 50° C. for 60 minutes, the sample was washed with water and dried.

Next, it was immersed in a 20% formic acid aqueous solution at 25°C for 30 minutes, and after washing with water, 100 g/12 of sulfuric acid and 20 g/20 g of sodium percarbonate were added.
After being immersed in an aqueous solution of the mixture of Q at 45° C. for 180 minutes, washed with water and dried, nickel plating was performed under the same conditions as in Example 1. As a result, a uniform plating film was obtained.

The amount of plating film is 24% OWf, and the surface electrical resistance is 1.5.
The conductivity was good at Ω/'cm.

The results of repeatedly attaching and detaching the plated A side and B side 50 times are shown in Table 2 below, and Example 2 according to the present invention
is better.

Table 2 Example 3 Polyvinylidene chloride filament mesh (thread ff1O
, 1 mm, 60 mesh/inch) was degreased and refined in a 5 g/Q aqueous solution of a nonionic surfactant (Noigen WS-20; Dai-Kogyo Seiyaku) at 40°C for 60 minutes, and washed with water.

Next, it was immersed in a 25% tetrahydro 7 run aqueous solution at 25°C for 60 minutes, squeezed, washed with water, and then immersed in iodine 10g/
A mixture of Q and potassium iodide 15g/12 in an aqueous solution at 25°C.
It was soaked in water for 60 minutes and washed with water.

Next, sulfur R80g/Q and hydrogen peroxide (35%) 15g/
After being immersed in an aqueous mixture solution of No. 12 at 45° C. for 180 minutes, washed with water and dried, electroless copper plating was performed under the following conditions.

As a plating catalyst, a mixed solution of 50rnQ of palladium chloride and tin chloride (Catalyst OPCSO; Okuno Pharmaceutical Co., Ltd.), 160mQ of hydrochloric acid, and 790mQ of water was prepared.

The treated polyvinylidene chloride filament mesh was immersed in this solution for 2 minutes at 25°C, washed with water, and then immersed in a mixture of 50 mQ of sulfuric acid and 950 m of water as an activation bath for 3 minutes at 45°C. Palladium chloride was fixed to the fibers.

After that, it was washed with water and placed in an electroless copper plating bath with the following composition at 28°C.
By dipping in C for 3 minutes, a uniform copper plating film was obtained.

Copper plating bath composition> Copper nitrate 15g/(sodium bicarbonate 1Oll) Tartrate 30l/38% formalin solution 100mQ/QpH+11.5 The formed copper layer was 25% OWf, and the surface electrical resistance was 0.5
It was a good metal film with a resistance of Ω/cm or less.

Comparative Example 3 The same polyvinylidene chloride filament mesh used in Example 3 (thread diameter 0.1 mm, 60 mesh/inch)
was degreased and scoured in an aqueous solution of 5 g of nonionic surfactant (Noigen WS-20; manufactured by Dai-Kogyo Seiyaku Co., Ltd.) at 40°C for 60 minutes, washed with water, and dried.

Next, it was immersed in a 25% aqueous solution of tetrahydrofuran at 25°C for 60 minutes, squeezed, and washed with water.

After that, 80g/Q of sulfuric acid and 15g of hydrogen peroxide (35%)
/12 mixture aqueous solution at 45°C for 180 minutes,
After washing with water and drying, it was immersed in an electroless plating bath at 28° C. for 3 minutes under the same conditions as in Example 3 to obtain a uniform copper plating film.

The results of comparing the adhesion strength of the metal film of the product of Example 3 with the adhesion strength of the metal film of the product of Comparative Example 3 are as shown in 3 below, and the product obtained by the method of the present invention has stronger adhesion. was large.

<Measurement method> Academic friction test: JIS L 0849 load 200g
I rubbed it 50 times.

Cellophane tape method: Use commercially available cellophane tape with a length of 5 to 7 cm.
Cut it and firmly press it to the test surface.

After 10 minutes, the cellophane Cheeburr Peel off with care and transfer to cellophane tape. The degree of photocopy was evaluated.

Table 3 Example 4 ABS resin plate (commercial product, thickness 2 mm) After heat treatment at 120°C for 10 minutes, nonionic surfactant (XO-7; Kaisei Chemical) 5g/(2) was heated at 50°C in an aqueous solution of After degreasing and scouring for 30 minutes, it was washed with water and dried.

Next, Tetra 110F 9F was immersed at 0°C for 60 minutes, washed with water, and potassium iodide 10
It was immersed in g/Q aqueous solution at 30°C for 60 minutes and washed with water.

Next, it was immersed in an aqueous solution of a mixture of 100 g/(l) of sulfuric acid and 20 g/Q of ammonium persulfate at 45°C for 180 minutes, washed with water, and dried.

After that, electroless copper plating was performed under the same conditions as in Example 3, and as a result, a uniform mirror-like copper plating film was obtained. The surface electrical resistance was 0.50/cm.

Comparative Example 4 After degreasing and scouring the same ABS resin plate as in Example 4, it was immersed in Tetra 110F9F10 for 60 minutes, washed with water, and then soaked in a mixed aqueous solution of 100 g/Q of sulfuric acid and 20 g/Q of ammonium persulfate. to 45
It was soaked for 180 minutes at °C, washed with water, and dried.

Thereafter, electroless copper plating was performed under the same conditions as in Example 3. As a result, a mirror-like copper plating film was obtained, and the surface electrical resistance was 0.5Ω/cm.

Table 4 shows the results of comparing the adhesion strength of the plating film between the product of Example 4 and the product of Comparative Example 4 using the peel test method described in Example 1. The adhesion strength is greater.

Table 4 Example 5 Polyoxymethylene resin plate (Duracon, thickness 2
mm; made of polyplastic) for 2 minutes at 100°C, then 5 g of nonionic surfactant (XO-7; made by Tasei Kagaku)
/+2 aqueous solution at 50'C for 30 minutes, followed by washing with water and drying.

Next, 60 g of potassium bromide was added to a 10 g/12 aqueous solution at 40°C.
Soak for 1 minute, rinse with water, then soak with caustic soda.

g/Q and hydrogen peroxide 20g/Q in an aqueous solution of 4
After soaking at 5°C for 180 minutes, it was washed with water and dried.

Next, electroless copper plating was performed under the same conditions as in Example 3. As a result, a uniform copper plating film was formed.

Comparative Example 5 The same polyoxymethylene (Duracon) as in Example 5 was
After heat treatment at 00℃ for 2 minutes, nonionic surfactant (XO-
7; Made by Utagasei Chemical Co., Ltd.) 3 at 50°C in an aqueous solution of 5 g/Q
After degreasing and scouring for 0 minutes, dry.

Next, caustic soda 1Og/I2 and hydrogen peroxide 20g/Q
After being immersed in an aqueous solution of the mixture at 45°C for 180 minutes, it was washed with water and dried.

As a result of performing electroless copper plating in the same manner as in Example 5, a nonuniform copper plating film was formed.

The results of comparing the adhesion strength of the steel plating film between Example 5 and Comparative Example 5 are shown in Table 5, and the plating film of the product of Example 5 formed by the method of the present invention was stronger. .

Table-5

Claims (1)

[Claims] 1. In a method for forming a metal coating on the surface of a synthetic resin structure by electroless plating, prior to electroless plating,
The method is characterized in that after attaching iodine, iodide, bromine and/or bromide to the surface of the synthetic resin structure on which the metal coating is to be formed, the surface of the structure is brought into contact with an inorganic peroxide. A method for metal coating the surface of synthetic resin structures. 2. The surface of the synthetic resin structure on which the metal coating is to be formed,
2. The method according to claim 1, wherein the synthetic resin is treated with a liquid containing a solvent before or at the same time as the adhesion treatment.