JPS621877A - Method for plating molded body of polyethylene terephthalate with metal - Google Patents

Abstract

PURPOSE:To form a metallic film having superior adhesion by plating with high reproducibility by etching and pretreating a molded body of polyethylene terephthalate and immersing it in palladium hydrosol contg. an anionic surfactant. CONSTITUTION:A molded body of polyethylene terephthalate is etched by immersion in an aqueous soln. of an alkali metallic hydride. The molded body is immersed in an aqueous soln. of a cationic surfactant or metallic hydroxide hydrosol. The pretreated molded body is immersed in palladium hydrosol contg. one or more kinds of compounds selected among anionic surfactants, nonionic surfactants and water soluble polymers such as polyvinylpyrrolidone to stick palladium colloid to the surface of the molded body. The palladium hydrosol contains no impurities, has stability for a long period and forms palladium colloid having high catalytic activity. The treated molded body is chemically plated. A metallic film having superior adhesion is simply formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metal plating method for a polyethylene terephthalate molded body, and more specifically, a polyethylene terephthalate molded body (hereinafter simply referred to as a PET molded body). By applying palladium colloid having a certain high catalytic activity to the surface of the PET molded body and then chemically plating it, a metal plating film with excellent adhesion can be formed on the surface of the PET molded body with good reproducibility with a simple operation. The invention relates to a metal plating method that has been made possible.

PR on which the metal coating according to the present invention is formed? The main uses of molded products include decorative materials, electromagnetic shielding materials for anti-elimination, capacitor materials, and magnetic recording tapes because conductivity or magnetic functions can be produced depending on the type of metal coating formed.

[Conventional technology]

The surface of a PET molded product is generally inert, so in order to form a metal film on the surface of a PET molded product by chemical plating, PR? After etching the surface of the PUT compact, it is necessary to apply palladium to the surface of the PUT compact as a catalyst for causing a reduction reaction of metal ions.

Conventionally, methods for adding palladium to the surface of PET molded bodies include, for example, Journal Saipu Applied
Physics (Journal of Applied
Physics) 36% (1965) No. 948
There is a method described on page.

In this method, chromic acid is added to a solution of stannous chloride in hydrochloric acid.
P etched with sulfuric acid and sodium hydroxide
[Two steps: sensitization treatment in which the iT molded body is immersed and then washed with water, and activation treatment in which the sensitized PET molded body is immersed in an acidic solution of palladium chloride in hydrochloric acid to precipitate palladium on the surface of the PET molded body. Consists of processes.

Furthermore, as a method for imparting palladium in one step, there is, for example, the method described in US Pat. No. 3,011,920.

The method described in US Pat. No. 3,011,920 involves contacting a substrate with a strongly acidic palladium-tin colloidal solution to impart palladium that acts as a catalyst for chemical plating. This strongly acidic palladium-tin colloidal solution can be used, for example, as a palladium-tin colloidal solution.
tion of the institute of
Metal Finishing) Volume 51 (197
3) As described on page 63, it is used for activation treatment of ABS resin, etc., but it is not used for PET molded bodies.

[Problem that the invention seeks to solve]

In the case of using the method described in the above-mentioned Jartle Saip 7 BlyF Physics, two baths of stannous chloride and palladium chloride are required, and in order to prevent the two baths from mixing with each other, one bath is required for each treatment. The process is very complicated as it requires washing with water. Furthermore, since the catalytic activity for chemical plating is low, it has the disadvantage that sufficient palladium cannot be applied to induce a reduction reaction of metal ions unless the same treatment is repeated two or three times.

In the method described in the above-mentioned US Pat. No. 3,011,920, in addition to palladium, which acts as a catalyst for chemical plating, a large amount of tin hydroxide etc. is also applied to the substrate, so these impurities can be used to prevent chemical plating. In addition, it becomes a cause of weakening the adhesion strength between the formed metal film and the substrate. Therefore, after bringing the substrate into contact with a strongly acidic palladium-tin colloidal solution to remove impurities other than palladium, it is necessary to further immerse the substrate in an acid or alkaline solution (acceleration treatment).

Moreover, this strongly acidic palladium-tin colloidal solution changes over time and begins to precipitate 3 to 4 months after its preparation, and has the drawback of lacking stability and reproducibility.

As mentioned above, we have established a method to form a highly reproducible metal plating film with excellent adhesion by applying palladium with a certain high catalytic activity to the surface of a PUT molded body through a simple operation, and then chemically plating it. This is currently the most requested.

[Means for solving the problem] The inventor is a PR? The present invention was achieved as a result of various studies on a method of imparting palladium, which has a certain high catalytic activity, to the surface of a molded body by simple wet application.

That is, in the present invention, the surface of the target PET molded body is etched with an aqueous solution of an alkali metal hydroxide, and then treated with an aqueous cationic surfactant solution or a metal oxide hydrosol (colloidal solution). Palladium colloid is applied to the surface of the PET molded body by immersing it in a palladium hydrosol containing one or more selected from anionic surfactants, nonionic surfactants, and water-soluble polymers. This is a metal plating method for a PET molded body, which comprises applying a PET powder and then chemically plating it.

C action] First, the most important point in the present invention is that after the PET molded body is etched with an aqueous solution of an alkali metal hydroxide, it is treated with an aqueous cationic surfactant solution or a metal oxide hydrosol, and the PET molding is performed. When applying palladium, which acts as a catalyst for chemical plating, to the surface of the body,
The point is to use a palladium hydrosol containing one or more selected from anionic surfactants, nonionic surfactants, and water-soluble polymers.

In the present invention, palladium hydrosol containing one or more selected from anionic surfactants, nonionic surfactants, and water-soluble polymers is extremely stable. It can be stored for a long time and can be used at any time, and since it does not contain impurities that would interfere with the catalytic action, it does not require accelerating treatment as in conventional methods. After treating the PUT molded body etched with an oxide aqueous solution with a cationic surfactant aqueous solution or metal oxide hydrosol,
A palladium colloid having a certain high catalytic activity can be provided by a simple scraping process such as immersion in the palladium hydrosol.

Next, various conditions for implementing the method of the present invention will be described.

As the PET molded body in the present invention, various PET molded bodies such as sheet-like, powder-like, pellet-like, and filament-like can be used.

In the present invention, the etching treatment of the PE↑ molded body is performed using PU
The T molded body is immersed in an aqueous alkali metal hydroxide solution at a temperature ranging from room temperature to the boiling point, preferably from 50 to 90°C for 10 minutes or more. It is preferable that the PET molded body used be warmed and degreased with ethanol or the like, then washed with water and dried.

As the alkali metal hydroxide aqueous solution used in the etching process in the present invention, a sodium hydroxide or potassium hydroxide aqueous solution is suitable, and the concentration thereof is 1 to 10'mol#! is desirable.

The cationic surfactant aqueous solution in the present invention includes:
A quaternary ammonium salt type such as stearyltrimethylammonium chloride or dodecylpyridinium chloride dissolved in an aqueous solution at a concentration of 0.1 to 5% can be used.

The metal hydroxide hydrosol in the present invention is, for example, an iron hydroxide hydrosol obtained by rapidly hydrolyzing an iron chloride (2) aqueous solution in boiling pure water, or an iron hydroxide hydrosol produced by a gas phase method. A hydrated aluminum oxide hydrosol prepared by dispersing commercially available aluminum oxide in water can be used.

In the present invention, the etched PET molded body can be treated with a cationic surfactant or metal hydroxide hydrosol by immersing it at a temperature in the range from room temperature to 100° C. for 5 minutes or more.

The palladium hydrosol in the present invention is a palladium salt aqueous solution such as palladium chloride (1), and one or two kinds of protective agents selected from anionic surfactants, nonionic surfactants, and water-soluble polymers. It can be obtained by reduction treatment with a water-soluble reducing agent such as sodium borohydride or hydrazine in the presence of the above (for example, JP-A-59-120249).

Examples of anionic surfactants include sulfonic acid type surfactants such as sodium dodecylbenzenesulfonate, nonionic surfactants such as polyethylene glycol-P-monononylphenyl ether, and water-soluble polymers such as polyvinyl. Pyrrolidone and the like can be used, and when used, these surfactants and water-soluble polymers can be used alone or in combination of two or more.

The concentration of surfactant and water-soluble polymer is 0.002 to 0.
．． A range of 1% is preferred.

The palladium concentration in the palladium hydrosol used in the present invention is 0.1 to 2 mg -atom/j! A range of is preferred.

In the present invention, the PET molded article can be immersed in palladium hydrosol at a temperature ranging from room temperature to 100° C. for at least 1 minute, preferably at least 10 minutes, and then pulled up and washed with water.

Chemical plating in the present invention can be performed by a conventional method. That is, in a solution containing metal ions and a reducing agent, the metal ions are reduced in the palladium colloid portion, thereby precipitating the metal.

The metal ion solution for chemical plating in the present invention includes neutral or alkaline nickel, cobalt, copper, etc., which are commonly used to impart electrical and magnetic properties.
A species or two or more species can be used.

As the reducing agent for chemical plating in the present invention, sodium hypophosphite, formaldehyde, etc. can be used.

〔Example〕

Next, the present invention will be explained by examples.

The magnetism in the examples was measured in a magnetic field of 10 koe.

The surface resistance was measured using an MCP-TESTER-LORESTA low resistance surface resistance meter (manufactured by Mitsubishi Yuka Corporation).

The adhesion of the plating was examined by firmly pasting Scotch mending tape (manufactured by Sumitomo Sumitomo 17-4 mm) onto the plated material and peeling it off one hour after the completion of plating.

Example 1 After washing with ethanol for 10 minutes, washing with water and drying PET film for magnetic tape (manufactured by Toshi ■, thickness: 20.81mm)
ta, 4c+wX2.5cm) 6 mol/41
immersed in a 50°C aqueous solution containing sodium hydroxide,
After 60 minutes, the sample was pulled up and washed with water to perform etching treatment.

16. While stirring in boiling pure water 750+++1.
Pour 12 ml of 5 mmol iron chloride (2) aqueous solution to make a deep red iron hydroxide (2) hydrosol, and then add 82 ml of iron chloride (2) aqueous solution with pure water.
It was diluted to 51. The above PE subjected to etching treatment was placed in 100 ml of the hydrosol of iron hydroxide (2) thus obtained.
The T film was immersed at a temperature of 80°C, and after 30 minutes, the film was pulled up and thoroughly washed with water.

Separately, palladium chloride ([50 μ*ol, 250 μl
It was dissolved in an aqueous solution containing 2.51 mol of sodium chloride, and then diluted to 94 ml with pure water. An aqueous solution containing 110 liters of sodium dodecylbenzenesulfonate while vigorously stirring this solution? Add eiII111,
Subsequently, when 5 ml of an aqueous solution containing 200 μs+ol of sodium borohydride was added dropwise, the color of the solution suddenly changed, and a transparent black-brown palladium hydrosol containing an anionic surfactant was obtained.

The above PET film treated with iron (2) hydroxide hydrosol was immersed in this palladium hydrosol at room temperature for 30 minutes, and then the film was pulled up and washed with water to obtain a PET film with palladium colloid added to the surface. .

Next, 0.03 n+ol of cobalt sulfate (1) heptahydrate, 0.25 mol of sodium hypophosphite, 0.5
Sodium tartrate dihydrate of 01101 and 0.50 m
ol of boric acid was dissolved in pure water to make 142, and 3.
The PET film provided with the palladium colloid was immersed at a temperature of 90° C. into a cobalt chemical plating solution in which p■ was adjusted to 9.0 by adding 3 mat/J aqueous sodium hydroxide solution. After immersing for 3 minutes, the film is pulled up, washed with water, and dried, leaving a thickness of 0.5 mm on the surface of the PET film.
A cobalt metal film with good adhesion to 56μ steel was formed.

Even when the mending tape was strongly pressed against the surface of this PET film and peeled off, the cobalt film did not separate.

In addition, the saturation magnetic flux density of this PET film is 9500G
auss-, and the coercive force was 7900e.

Example 2 0.2 g of aluminum oxide powder (manufactured by Japan 7I Olu ■)
In a hydrated aluminum oxide hydrosol prepared by dispersing Alua+inium Oxide C') in 100 ml of pure water at room temperature, a PET film (Tokyo Co., Ltd.) was washed and etched with ethanol in the same manner as in Example 1. Made in Japan, thickness 20.8μ, 4
cm x 2.5 cm) was immersed at a temperature of 80°C. After 30 minutes, the film was pulled up and thoroughly washed with water, and the film was prepared as in Example 1 except that polyethylene glycol mono-P-nonylphenyl ether (polymerization degree of the polyethylene glycol portion was 10) was used as a surfactant.
80°C in a palladium hydrosol prepared in the same manner as
immersed at a temperature of

After 30 minutes of immersion, the film was pulled up and washed with water, thereby imparting palladium colloid to the PET film surface. This PET film was immersed in a cobalt chemical plating solution prepared according to the procedure of Example 1 at a temperature of 90° C., and after 3 minutes was taken out, washed with water, and dried.

Even when the mending tape was strongly pressed against the surface of this PET film and peeled off, the cobalt film did not peel off.

In addition, the saturation magnetic flux density of this PUT film is 13500
Gauss, and the coercive force was 8450e.

Example 3 A filamentous PET molded body (manufactured by J Nichika, manufactured by J Nichika) was washed with ethanol and etched in the same manner as in Example 1, and then immersed in hydrated aluminum oxide hydrosol in the same manner as in Example 2.
Palladium colloid was applied to the surface of 5A1265 (unstretched, diameter 0.2211111) in the same manner as in Example 2.

Separately, 0.05 mol of cobalt sulfate (1) heptahydrate,
0.2mo! of sodium hypophosphite, 0.2 mol
Trisodium citrate dihydrate and 0.5 mol of ammonium sulfate were dissolved in pure water to make 11, and 10
mol/j! Add ammonia aqueous solution to adjust the pH to 10.
The PIliT molded body to which palladium colloid was applied was immersed in a cobalt chemical plating solution adjusted to C for 15 minutes at 90°C.

Plating was done.

The surface of the obtained PET molded product had a silvery white color, and the cobalt film did not peel off even when the mending tape was strongly pressed and peeled off. Moreover, the saturation magnetic flux density of this PET molded body was 9200 Gauss, and the coercive force was 3340e.

Example 4 A PET film (11100 manufactured by Dia*Ile ■, thickness 100 μm, 3c+mX 2c+*) was subjected to ethanol cleaning and etching treatment according to the same procedure as in Example 1.
was immersed in an aqueous solution containing 1% dodecylpyridinium chloride at room temperature.

After 30 minutes, the 2 films were pulled up and thoroughly washed with water, and then immersed in the palladium hydrosol used in Example 2 for 60 minutes at a temperature of 80° C., thereby imparting palladium colloid to the PET film surface.

Next, 1 mol of nickel chloride C110 was added to 211IO
Dissolve in 500 ml of 1/1 ammonia aqueous solution and add 0.
2 mol/j! 500 ml of sodium hypophosphite
The PET film to which palladium colloid was added was immersed at a temperature of 60° C. into a nickel chemical plating solution obtained by adjusting ρ■ to 8.9 with concentrated hydrochloric acid.

After 10 minutes, the film is pulled up, washed with water, and dried to reveal a metallic luster with the surface uniformly coated with nickel.
E↑ film was obtained.

The thickness of the nickel coating determined from the weight increase of the film before and after plating was 0.50 μm, and even when the mending tape was strongly pressed against this surface and removed, the nickel coating did not peel off at all.

Moreover, the surface resistance of this PET film was 2.0Ω.

Comparative Example 1 A strongly acidic palladium-tin colloidal solution was prepared according to the procedure of Example 1 of US Pat. No. 3,011,920. A PET film (manufactured by Dianail ■, 1125
, 125+17 m thick, 3 cm x 2 cm) was immersed in the freshly prepared palladium-tin mixed catalyst solution at room temperature. After 60 minutes, pull up the PET film, wash it thoroughly with water, and then do its PR? 1.25mo film
l/j! of sodium hydroxide solution at room temperature. After 5 minutes of immersion, the PET film was pulled up and thoroughly washed with water to remove impurities other than palladium, and then immersed in a nickel chemical plating solution in the same manner as in Example 1, but no plating occurred.

Comparative Example 2 Nickel chemical plating was attempted in the same manner as Comparative Example 1, except that a palladium-tin mixed catalyst solution that had been prepared for three months was used.

A nickel metal film was only formed on a small portion of the PET film surface. Note that the palladium-tin colloidal solution that had been prepared for a long time of 4 months or more was partially or completely agglomerated to form a blackish brown precipitate.

〔effect〕

As shown in the above example, the method for metal plating a PET molded body according to the present invention is such that the palladium hydrosol used in the present invention does not contain impurities that interfere with the catalytic action of chemical plating, and can be used for a long period of time. Since it is stable, it is possible to provide a palladium colloid with a certain high catalytic activity, and it is therefore possible to form a metal plating film with excellent adhesion on the surface of a PUT molded body.

Claims (1)

[Claims] (1) When forming a metal coating on the surface of a polyethylene terephthalate molded body by chemical plating, the target polyethylene terephthalate molded body is etched with an aqueous solution of an alkali metal hydroxide, and then an aqueous solution of a cationic surfactant or After treatment with metal hydroxide hydrosol, immersion in palladium hydrosol containing one or more selected from anionic surfactants, nonionic surfactants, and water-soluble polymers. 1. A method for metal plating a polyethylene terephthalate molded body, which comprises applying palladium colloid to the surface of the polyethylene terephthalate molded body, and then chemically plating the polyethylene terephthalate molded body.