JP2006045653A - Plated member and production method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plated member plated with a Ge-containing alloy, and to provide a production method therefor. <P>SOLUTION: In the plated member, a plating film of an alloy comprising Ge as an essential component is formed on the surface. The plating film is formed by an electroplating method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plated member and a method for producing the same, and more specifically, the surface is coated with a plating film made of a platinum group element or an alloy of Au and Ge, and particularly when the platinum group element is Rh, the bluish black color The present invention relates to a novel plated member whose surface is coated with a plating film of Ge—Rh alloy having a metallic luster and giving a noble feel, and a method for producing the same.

In the decoration industry, various accessories such as glasses, necklaces, rings, earrings, bracelets, and tie pins are not only harmless to the human body, but also contribute to health promotion and have a beautiful appearance at the same time. Development of products with high-class use value is underway.
For example, the following materials for jewelry have been proposed (see Patent Document 1).

This material is a Ge-containing alloy developed by paying attention to the far-infrared effect and blood flow promoting action of Ge. This alloy is a Ge-In-Ag alloy composed of Ge: 1 to 9% by mass, In: Ge of 2 to 20% by mass, and the balance being made of Ag. Has a metallic luster.
This alloy is prepared by melting and mixing each component at a predetermined amount ratio to form an alloy, and then processing the alloy into a predetermined shape for use.

However, this alloy exhibits difficult processability as the Ge content increases, and for example, it becomes difficult to process into thin pieces or to perform precise decoration processing.
Such a problem can be solved by coating the surface of the material to be plated, which has been precisely processed, with a plating film of a Ge-containing alloy by electroplating. For this reason, in the decorative article industry, earnest research has been repeated on the formation of a plating film made of a Ge-containing alloy. However, to date, there has been no case where a plating film made of a Ge-containing alloy has been successfully formed by an electroplating method. The biggest reason is that an appropriate plating bath has not yet been developed.

Further, in the field of jewelry, there is an increasing demand for those with a black surface color and a metallic luster. And development research for producing it by electroplating is underway.
By the way, as black plating, black Cr plating, black Ni plating, etc. are known conventionally. However, these plating films are all poor in metallic luster and inferior in decorative effect. Moreover, in the case of these plating films, there is a problem that Cr is repelled as a component harmful to the environment and the human body, and Ni is repelled as a component causing skin allergy, for example. For these reasons, the following black plating film has been proposed (see Patent Document 2).

This plating film is a black Rh plating film having a specular gloss. Moreover, this plating film has excellent adhesion to the material to be plated, excellent corrosion resistance, and high hardness.
This plating film is formed by electroplating using a plating bath containing a rhodium salt such as rhodium sulfate, a free acid such as sulfuric acid, and a hypophosphite salt such as sodium hypophosphite.

However, in the case of the technique disclosed in Patent Document 2, it cannot be said that the plating bath to be used is necessarily stable and the deposition efficiency of Rh is not high. Therefore, there is a problem that when thick plating is performed in order to realize a clear black gloss, the time required for plating becomes very long and productivity is lowered.
JP 2000-144283 A Japanese Patent Publication No. 1-43033

  An object of this invention is to provide the novel plating member coat | covered with the electroplating film of Ge containing alloy, and its manufacturing method.

In order to achieve the above object, in the present invention,
A plated member having a plating film formed of an alloy containing Ge as an essential component on the surface, in particular, the Ge content in the alloy is 1 to 90% by mass, and the alloy is a Ge-Rh alloy. , A Ge—Ru alloy, a Ge—Pd alloy, a Ge—Pt alloy, or a Ge—Au alloy.

In the present invention,
A plating film is formed by electrodepositing a Ge-containing alloy on a material to be plated using an acid plating bath containing Ge source, an element source that forms an alloy with Ge, an organic acid, an alkali component, and a free acid as essential components. A method of manufacturing a plated member is provided.

  This plating member contains 1 to 90% by mass of Ge in the plating film, and when the plating film is a Ge-Rh alloy, it exhibits a noble black luster, so that the effect of Ge on the human body is effectively exhibited. Its value is great as a new luxury accessory.

In the plated member of the present invention, the plating film covering the surface is made of a Ge-containing alloy. Specifically, it is made of a Ge—Rh alloy, a Ge—Ru alloy, a Ge—Pd alloy, a Ge—Pt alloy, or a Ge—Au alloy. And Ge content in these alloys is 1-90 mass%.
This plated film has a unique color tone depending on the kind of Ge counterpart material and Ge content in the alloy, but it has a specular gloss in any alloy.

For example, in the case of a plating film made of a 48.8% Ge-51.2% Rh alloy in Examples described later, it has a bluish black gloss and a color tone that gives a noble impression. Moreover, in the case of the plating film which consists of 50% Ge-50% Au, it is a bluish golden color.
This plating member is manufactured by an electroplating method.
First, as a plating bath, an acidic plating bath containing a Ge source, an element source that forms an alloy with Ge, an organic acid, an alkali component, and a free acid as essential components is prepared.

As the Ge source, for example, germanium sulfate, germanium chloride, germanium nitrate, potassium germanate, germanium dioxide and the like can be used.
As the alloy element source, the following various compounds are used.
For example, rhodium sulfate, rhodium chloride, rhodium phosphate, or the like is used as the Rh source when a Ge-Rh plating film is to be formed.

As the Ru source in the case of the Ge—Ru plating film, for example, ruthenium sulfate, ruthenium chloride, ruthenium sulfamate, or the like is used.
As the Pd source in the case of the Ge—Pd plating film, for example, palladium sulfate, palladium chloride, palladium ammonia acetate and the like are used.
As the Pt source in the case of the Ge—Pt plating film, for example, platinum sulfate, platinum nitrite or the like is used.

Further, as the Au source of the Ge—Au plating film, for example, cyanogen gold potassium and chloroauric acid are used.
The concentration of the Ge source and the alloy element source during the preparation of the plating bath may be determined as appropriate in relation to the target value of the Ge content in the plating film to be formed.
As the organic acid in the plating bath, for example, one or more of citric acid, sulfamic acid, glycolic acid, acetic acid, succinic acid, malic acid and the like can be used. And it is preferable that the density | concentration in the plating bath of these organic acids shall be about 0.1-200 g / L.

As the alkali component, for example, potassium hydroxide, sodium hydroxide, and the like can be used. Of these, potassium hydroxide is preferable. And it is preferable that the density | concentration of these alkali components shall be about 5-200 g / L. This alkaline component may be used as an aqueous solution having a concentration of 5 to 200N.
As the free acid, any acid commonly used in acidic plating baths may be used. For example, sulfuric acid, hydrochloric acid, phosphoric acid, sulfamic acid and the like can be used. And the usage-amount is set to the quantity which can ensure the pH of a plating bath to the acidity of 5.5 or less.

The pH of the plating bath is preferably set to 5.0 or less. When the pH is higher than 5.0, it is difficult to form a plating film having a target composition because Ge or a hydroxide of its counterpart element is generated.
What is necessary is just to set the temperature of a plating bath to the appropriate temperature in the range of normal temperature to 60 degreeC. This is because if the temperature is lower than room temperature, the deposition efficiency is deteriorated, and if the temperature is higher than 60 ° C., evaporation of the plating bath proceeds and the variation of the bath composition becomes severe.

The current density is preferably set in the range of 0.1 to 10 A / dm ^2. This is because when the density is lower than 0.1 A / dm ² , the deposition rate is slow, and when the density is higher than 10 A / dm ² , burns occur and a glossy plating film cannot be formed.

Example 1
A plating bath was constructed using the following ingredients.
Germanium dioxide: 13 g / L (converted to Ge), rhodium sulfate: 2 g / L (converted to Rh), sulfamic acid: 50 g / L, glycolic acid: 50 g / L, citric acid: 50 g / L, potassium hydroxide: 40 g / L , Sulfuric acid: 80 g / L.

This plating bath is strongly acidic, and its pH is 0.5 at a temperature of 30 ° C.
The temperature of this plating bath was controlled to 45 ± 2 ° C., an insoluble electrode made of Ti as an anode, a copper foil as a cathode, and electroplating at a current density of 3 A / dm ² were performed for 6 minutes.
A bluish black glossy plating film was formed on the surface of the copper foil. The thickness was about 1 μm.

X-rays were irradiated to the plating film surface of the copper foil, and a fluorescent X-ray energy spectrum was measured. For the measurement, Fischer scope X-RAY XDL (manufactured by Fischer) was used. The results are shown in FIG.
The following is clear from FIG.
(1) Cu energy peak near 2θ: 60 °, Ge energy peak near 2θ: 75 °, and Rh energy peak around 2θ: 155 ° are observed.

In this spectrum diagram, the ratio of the energy peak of each component is Cu: 91.4%, Ge: 4.2%, Rh: 4.4%.
(2) A plating film made of Ge—Rh is formed on the surface of the copper foil. The plating film has an alloy composition of Ge: 48.8% by mass and Rh: 51.2% from the calculation of the energy peak described above.

In addition, the following artificial sweat immersion test was done with respect to this plating film.
Sodium chloride: 9.9 g / L, sodium sulfate: 0.8 g / L, urea: 1.7 g / L, lactic acid: 1.7 mL / L, ammonium: 0.2 mL / L, temperature: 40 ° C., pH: 5. The plated member was immersed in the test aqueous solution No. 6 for 48 hours and then taken out, and the state of the plated film was visually observed.

Neither discoloration nor corrosion was observed in the plating film, and it was confirmed that this plating film had excellent corrosion resistance.
Further, when the copper foil was dissolved with nitric acid, the plating film remained in the form of fine flakes without being powdered. When the flake aggregate was sufficiently washed with water and then left to dry in a dryer at a temperature of 100 ° C. for one day, a phenomenon was observed in which the weight increased by about 30%. This may be because, for example, oxygen in the atmosphere is occluded.
Example 2
A plating bath was constructed using the following ingredients.

Potassium germanate (converted to Ge): 10 g / L, rhodium sulfate (converted to Rh): 2 g / L, potassium citrate: 20 g / L, malic acid: 30 g / L, potassium hydroxide: 30 g / L.
The pH of this bath is about 5.0. The temperature of this plating bath was controlled to 50 ± 2 ° C., an insoluble electrode made of Ti as an anode, and a copper foil as a cathode were arranged, and electroplating was performed at a current density of 2.0 A / dm ² for 6 minutes.

  A plating film having a black luster was formed in the same manner as the plating film of Example 1. The film thickness was about 1.0 μm.

In the plated member of the present invention, the plating film is made of a Ge-containing alloy. And when a plating film is a Ge-Rh alloy, the color tone is bluish black luster and exhibits the outstanding decoration effect.
Therefore, this plating member is very useful as an accessory that also has the effect of Ge.

  Further, by selecting a platinum group element having a catalytic action as the Ge counterpart, an unknown application such as a catalyst can be expected for this plated member.

2 is a fluorescent X-ray energy spectrum diagram of a plated member of Example 1. FIG.

Claims (4)

  A plated member, wherein a plating film of an alloy containing Ge as an essential component is formed on a surface.   The plated member according to claim 1, wherein the Ge content in the alloy is 1 to 90 mass%.   The plated member according to claim 1, wherein the alloy is any one of a Ge—Rh alloy, a Ge—Ru alloy, a Ge—Pd alloy, a Ge—Pt alloy, or a Ge—Au alloy.   A plating film is formed by electrodepositing a Ge-containing alloy on a material to be plated using an acidic plating bath containing Ge source, element source forming an alloy with Ge, organic acid, alkali component, and free acid as essential components. The manufacturing method of the plating member characterized by the above-mentioned.

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