JP2011117022A - Plating solution, plating film, ornament and clock - Google Patents

Abstract

An object of the present invention is to provide a plating solution which can stably form a plating film containing gold and copper, which can reliably prevent the occurrence of inconvenience such as clouding and has an excellent appearance over a long period of time.
The plating solution of the present invention contains gold ions and copper ions, and further contains a tellurium oxoacid compound. The gold ion content in the plating solution is preferably 8 g / L or more and 10 g / L or less, and the copper ion content in the plating solution is preferably 30 g / L or more and 40 g / L or less. The tellurium content in the plating solution is preferably 10 ppm or more and 220 ppm or less.
[Selection figure] None

Description

  The present invention relates to a plating solution, a plating film, a decorative article, and a watch.

  A decorative product such as a watch exterior part is required to have an excellent aesthetic appearance. Conventionally, in order to achieve such an object, a metal material such as Au, Pt, or Ag has generally been used as a constituent material of a decorative article. In particular, for the purpose of obtaining a decorative product having a color tone and appearance that cannot be expressed by a single metal, alloys such as pink gold exhibiting a metallic luster pink color are used. A plating solution as disclosed in Patent Document 1 has been used to manufacture a decorative article having such a pink Au plating film.

  However, when such a plating solution is used, there is a large variation in the color tone of the formed plating film, and it has been difficult to stably obtain a decorative product having an excellent appearance. In addition, in the conventional plating solution, appearance defects such as cloudiness are likely to occur, and in order to prevent this, benzenesulfonic acid, benzenesulfonamide, phenolsulfonic acid, 1,3,5-naphthalenesulfonic acid is contained in the plating solution. P-toluenesulfonamide, saccharin, sodium saccharin, formaldehyde, chloral hydrate, coumarin, 2-ptyne 1,4-diol, propargyl alcohol, thiourea, 2-pyridinecarboxylic acid, L-glutamic acid, polyethylene, polyamine, There have been attempts to add benzaldehyde-O-sodium sulfonate, 2-butene-1,4-diol, allyl sulfonate, pyrophosphate, citrate and the like. However, such additives are liable to be decomposed / deteriorated by electrolysis or decomposed / deteriorated over time, and the above-mentioned problems could not be reliably prevented over a long period of time. In addition, decomposition / degradation of the additive as described above is difficult to identify when it is contained in the plating solution (when multiple additives are used in combination, it is particularly difficult to identify). In order to ensure the quality of the plating film, it is necessary to periodically discard and replace the plating solution regardless of the degree of decomposition and deterioration of the additives in the plating solution. It was not preferable, and it was a factor that lowered the productivity of decorative products.

JP 59-80787 A

  An object of the present invention is to provide a plating film that contains gold and copper, reliably prevents the occurrence of inconveniences such as cloudiness, and has an excellent appearance, and forms the plating film stably over a long period of time. An object of the present invention is to provide a plating solution that can be used, to provide a decorative article including the plating film, and to provide a watch including the decorative article.

Such an object is achieved by the present invention described below.
The plating solution of the present invention is a plating solution containing gold ions and copper ions,
It contains a tellurium oxoacid compound.
Accordingly, it is possible to provide a plating solution that can stably form a plating film containing gold and copper, which can reliably prevent the occurrence of inconvenience such as cloudiness and has an excellent appearance over a long period of time.

In the plating solution of the present invention, the gold content in the plating solution is 8.0 g / L or more and 10.0 g / L or less,
The copper content in the plating solution is preferably 30 g / L or more and 40 g / L or less.
Thus, a pink and glossy plating film having a particularly excellent appearance can be obtained. Further, in the past, when forming a pink plating film, problems such as cloudiness were particularly likely to occur. However, in the present invention, even when such a pink plating film is formed, as described above Problems can be prevented reliably. That is, the effect of the present invention is more remarkably exhibited by using the above composition that can obtain a pink plating film.

In the plating solution of the present invention, the tellurium content in the plating solution is preferably 10 ppm or more and 1000 ppm or less.
Thereby, generation | occurrence | production of problems, such as a cloudiness, can be prevented more effectively and the aesthetic appearance of the plating film obtained can be made especially excellent. Further, the storage stability of the plating solution can be made particularly excellent, and it can be used for forming a plating film for a longer period.

In the plating solution of the present invention, the hydrogen ion index (pH) is preferably from 9.7 to 11.0.
Thereby, generation | occurrence | production of problems, such as a cloudiness, can be prevented more effectively and the aesthetic appearance of the plating film obtained can be made especially excellent. Further, the storage stability of the plating solution can be made particularly excellent, and it can be used for forming a plating film for a longer period.
The plating film of the present invention is formed using the plating solution of the present invention.
Accordingly, it is possible to provide a plating film that includes gold and copper, reliably prevents the occurrence of inconvenience such as cloudiness, and has an excellent appearance.

The decorative article of the present invention is characterized by including the plating film of the present invention.
Accordingly, it is possible to provide a decorative article including a plating film that includes gold and copper, reliably prevents the occurrence of inconvenience such as cloudiness, and has an excellent appearance.
The decorative article of the present invention is preferably a watch exterior part.
A watch is required to have a function as a practical product and an aesthetic appearance excellent as a decorative product. Further, a watch is generally used as an accessory in various environments, and is required to exhibit a stable and excellent appearance even in such different environments. According to the present invention, the decorative article can stably exhibit an excellent appearance even in various environments. That is, the effect of the present invention is more remarkably exhibited when applied to a watch exterior part.
The timepiece of the present invention is characterized by including the decorative article of the present invention.
Accordingly, it is possible to provide a timepiece including a plating film that includes gold and copper, reliably prevents occurrence of inconvenience such as cloudiness, and has an excellent appearance.

  According to the present invention, it is possible to provide a plating film containing gold and copper, reliably preventing the occurrence of inconveniences such as cloudiness, and having an excellent appearance, and stably forming the plating film over a long period of time. It is possible to provide a plating solution that can be used, to provide a decorative article including the plating film, and to provide a watch including the decorative article.

It is a fragmentary sectional view which shows suitable embodiment of the timepiece (portable timepiece) of this invention.

Hereinafter, preferred embodiments of the present invention will be described.
<Plating solution>
First, a preferred embodiment of the plating solution of the present invention will be described.
The plating solution of the present invention contains gold ions and copper ions. Thereby, the plating film of the external appearance of a golden-pink color tone can be formed.

  In particular, the present invention is characterized by further containing tellurium oxoacid compounds in addition to gold ions and copper ions. Thus, by including the tellurium oxo acid compound together with gold ions and copper ions, it is possible to suppress variations in the color tone of the plating film formed using the plating solution and to obtain a stable and excellent appearance. it can. In particular, it is possible to effectively prevent the occurrence of problems such as cloudiness over a long period of time and to form a plating film having a glossy and high-quality appearance. In addition, tellurium oxoacid compounds have superior durability compared to organic materials, and the content of the plating solution in the plating solution is easy to measure. Can be made appropriately. For this reason, it is possible to form a plating film and manufacture a decorative product including the plating film without exchanging / discarding the plating solution at unnecessary timing, which is resource-saving and environmentally friendly. Moreover, the productivity of the decorative product can be improved as a whole.

In the present invention, "tellurium oxoacid compound" refers to tellurium oxoacids (for example, H ₆ TeO ₆ , H ₂ TeO ₃ and polyacids condensed with these) and tellurium oxoacid salts (for example, (Na ₂ TeO ₄ , K ₂ TeO ₄ , PbTeO ₄ , Na ₂ H ₄ TeO ₆ , K ₂ H ₄ TeO ₆ , NaH ₅ TeO ₆ , KH ₅ TeO ₆ , Na ₂ TeO _3, etc.) The plating solution may be in a dissociated (ionized) state or in a non-dissociated state.

  The content of tellurium (Te) in the plating solution is preferably 10 ppm or more and 1000 ppm or less, more preferably 12 ppm or more and 700 ppm or less, and further preferably 15 ppm or more and 220 ppm or less. When the content of tellurium (Te) is a value within the above range, the occurrence of problems such as cloudiness can be more effectively prevented, and the aesthetic appearance of the resulting plating film can be made particularly excellent. it can. Further, the storage stability of the plating solution can be made particularly excellent, and it can be used for forming a plating film for a longer period. The tellurium content in the plating solution can be determined by measurement using an atomic absorption photometer or an inductively coupled plasma emission spectrometer (ICP).

  The gold (Au) content in the plating solution is 8.0 g / L or more and 10.0 g / L or less, and the copper (Cu) content in the plating solution is 30 g / L or more and 40 g / L. It is preferable that: Thus, a pink and glossy plating film having a particularly excellent appearance can be obtained. Further, in the past, when forming a pink plating film, problems such as cloudiness were particularly likely to occur. However, in the present invention, even when such a pink plating film is formed, as described above Problems can be prevented reliably. That is, the effect of the present invention is more remarkably exhibited by using the above composition that can obtain a pink plating film. In addition, the content rate of gold | metal | money and copper in a plating solution can be calculated | required by the measurement using an atomic absorption photometer and an inductively coupled plasma emission spectrometer (ICP).

As described above, the gold content in the plating solution is preferably 8.0 g / L or more and 10.0 g / L or less, but is 8.2 g / L or more and 9.7 g / L or less. More preferably, it is 8.5 g / L or more and 9.4 g / L or less. Thereby, the effect mentioned above is exhibited more notably.
Further, as described above, the copper content in the plating solution is preferably 30 g / L or more and 40 g / L or less, more preferably 32 g / L or more and 38 g / L or less, and 34 g / L. More preferably, it is 36 g / L or less. Thereby, the effect mentioned above is exhibited more notably.

  Further, the hydrogen ion index (pH) of the plating solution is preferably 9.7 or more and 11.0 or less, more preferably 9.9 or more and 10.8 or less, and 10.0 or more and 10.6 or less. More preferably. When the hydrogen ion index (pH) of the plating solution is within the above range, it is possible to more effectively prevent the occurrence of problems such as cloudiness, and the aesthetic appearance of the obtained plating film is particularly excellent. be able to. Further, the storage stability of the plating solution can be made particularly excellent, and it can be used for forming a plating film for a longer period.

Further, the content of CN ⁻ (free cyan concentration) in the plating solution is preferably 5.0 g / L or more and 10.0 g / L or less, but is 6.0 g / L or more and 9.5 g / L or less. More preferably, it is 7.0 g / L or more and 9.2 g / L or less. Thereby, electroplating can be suitably performed under conditions as described later. Incidentally, CN ^- content of (free cyanide concentration) can be readily determined by titration analysis.

<Plating film, method for forming plating film, and method for manufacturing decorative article>
The plating film of the present invention can be formed by wet plating using a plating solution as described above. The plating film formed by using the plating film of the present invention reliably prevents the occurrence of inconvenience such as cloudiness and has an excellent appearance. Moreover, since the plating film of the present invention is formed by wet plating using a plating solution, it should be suitably formed even if the plating film has a complicated shape that is difficult to cope with by dry plating. Can do.

In wet plating using the plating solution of the present invention, the plating film is generally formed by electrolytic plating so as to form a plating film on a substrate having a surface shape corresponding to the shape of the plating film to be formed.
After the plating film formed using the plating solution of the present invention is formed on a base material, it may constitute a decorative article together with the base material, or may be used by peeling from the base material It may be. That is, the plating solution of the present invention may be used for electroforming.

The base material on which the plating film is to be formed is one in which at least the vicinity of the surface of the part where the plating film is formed is made of a conductive material.
Moreover, it is preferable that the site | part by which the base material should form the plating film of this invention was comprised with the material containing gold | metal | money. As a result, the adhesion between the plating film of the present invention and the substrate can be made particularly excellent, and the durability and reliability of the decorative article equipped with the substrate and the plating film should be made particularly excellent. Can do. In addition, when a base-material main body is comprised with materials other than gold | metal | money, it is preferable to form a 24K gold plating layer by flash plating and to use this as a base material. The gold content in the plating solution used for flash plating is preferably 5 g / L or more and 10 g / L or less.

The average thickness of the gold plating layer by flash plating is not particularly limited, but is preferably 0.01 μm or more and 0.2 μm or less. Thereby, the effect by providing the gold plating layer (flash plating layer) as described above is more remarkably exhibited.
Wet plating using the above-described plating solution (plating solution used for forming a plating film composed of an Au-Cu alloy) is preferably performed under the following conditions.

  That is, the plating bath temperature is preferably 40 ° C. or higher and 75 ° C. or lower, more preferably 45 ° C. or higher and 70 ° C. or lower, and further preferably 55 ° C. or higher and 65 ° C. or lower. Thereby, the occurrence of problems such as color unevenness and cloudiness can be prevented more reliably, and the aesthetic appearance of the plating film can be made particularly excellent.

  The applied voltage during wet plating (electrolytic plating) is preferably 0.6 V or more and 2.0 V or less, more preferably 0.8 V or more and 1.7 V or less, and 1.0 V or more and 1.5 V or less. More preferably, it is as follows. As a result, it is possible to more reliably prevent the occurrence of problems such as uneven color and cloudiness while making the formation efficiency of the plating film sufficiently excellent, and to make the aesthetic appearance of the plating film particularly excellent it can.

  The plating treatment time is preferably 1 minute or longer and 30 minutes or shorter, more preferably 3 minutes or longer and 20 minutes or shorter, and even more preferably 5 minutes or longer and 15 minutes or shorter. Thereby, the aesthetic appearance of the plating film can be made particularly excellent while sufficiently improving the formation efficiency of the plating film.

  The average thickness of the plating film of the present invention formed as described above (plating film made of an Au—Cu alloy) is not particularly limited, but is preferably 1.0 μm or more and 5.0 μm or less. More preferably, it is 2.0 μm or more and 3.0 μm or less. When the average thickness of the plating film is within the above range, the plating film formation efficiency (decorative product productivity) is sufficiently excellent, and the durability of the decorative article including the substrate and the plating film is improved. Is particularly excellent, and a particularly excellent appearance can be obtained.

  In addition, the heat treatment (heat treatment and cooling treatment) and the acid treatment as described in detail below are applied to the plating film (plating film made of an Au—Cu alloy) obtained as described above. You may give it. Thereby, it is possible to more effectively prevent the occurrence of problems such as color unevenness in the plating film, the plating film can have a higher gloss, and have a particularly excellent appearance, The durability of the plating film and the decorative product can be made particularly excellent.

First, heat treatment (heating treatment and cooling treatment) that can be performed on the plating film will be described in detail.
The plating film is preferably subjected to a heat treatment of heating to 300 ° C. or more and 395 ° C. or less, and then a cooling treatment. Thereby, solid solution formation of the constituent material of the plating film is promoted, and the appearance and durability of the final plating film can be made particularly excellent.
As described above, the heating temperature during the heat treatment is preferably 300 ° C. or more and 395 ° C. or less, more preferably 320 ° C. or more and 390 ° C. or less, and more preferably 330 ° C. or more and 380 ° C. or less. preferable. Thereby, the effects as described above are more remarkably exhibited.

The heat treatment time (retention time at 300 ° C. or higher) is preferably 15 minutes or more and 180 minutes or less, more preferably 20 minutes or more and 150 minutes or less, and more preferably 30 minutes or more and 90 minutes or less. More preferably. Thereby, the effects as described above are more remarkably exhibited.
The cooling rate of the cooling treatment to 25 ° C. is preferably 0.02 ° C./second or more and 0.03 ° C./second or less, and is 0.022 ° C./second or more and 0.028 ° C./second or less. Is more preferably 0.024 ° C./second or more and 0.026 ° C./second or less. Thereby, the effects as described above are more remarkably exhibited.

Next, the acid treatment that can be performed on the plated film subjected to the heat treatment (heating treatment and cooling treatment) will be described in detail.
By performing an acid treatment on the plated film that has been subjected to the heat treatment as described above, it is possible to remove those components that do not constitute a solid solution among the components of the plated film, and the appearance of the plated film over time. Stability and the like can be made particularly excellent.

The acid treatment may be performed using an acid, but is preferably performed by bringing the plating film into contact with an aqueous HNO ₃ solution of 50 wt% or more and 70 wt% or less for 1 second or more and 180 seconds or less. Thereby, the above-described effects can be more remarkably exhibited while making the productivity of the decorative article sufficiently excellent. As described above, the contact time between the aqueous HNO ₃ solution and the plating film is preferably 1 second or more and 180 seconds or less, more preferably 1 second or more and 90 seconds or less, and 2 seconds or more and 60 seconds or less. More preferably. Thereby, the effects as described above can be more remarkably exhibited.
The treatment temperature during the acid treatment is preferably 5 ° C. or more and 50 ° C. or less, more preferably 7 ° C. or more and 35 ° C. or less, and further preferably 10 ° C. or more and 30 ° C. or less.

<Decoration>
Next, the decorative article of the present invention provided with the plating film as described above will be described in more detail.
As long as the decorative article is an article having a decorative property, for example, an interior such as a figurine, an exterior article, a jewelry, a watch case (a trunk, a back cover, a trunk and a back cover are integrated) One-piece cases, etc.), watch bands (including band clasps, band / bangle attachment / detachment mechanisms, etc.), dials, clock hands, bezels (eg, rotating bezels), crowns (eg, screw lock type crowns), Watch exterior parts such as buttons, cover glasses, glass edges, dial rings, parting plates, packings, movement ground plates, gears, train wheel bridges, rotating weights and other watch interior parts, glasses (for example, eyeglass frames), ties Pins, cufflinks, rings, necklaces, bracelets, anklets, brooches, pendants, earrings, earrings and other accessories, lighters or their cases Automobile wheel, sporting goods such as golf club, nameplate, panel, Shohai, various equipment parts, including other housing, etc., can be applied to various types of containers and the like. Among these, a watch exterior part is particularly preferable. A watch is required to have a function as a practical product and an aesthetic appearance excellent as a decorative product. Further, a watch is generally used as an accessory in various environments, and is required to exhibit a stable and excellent appearance even in such different environments. According to the present invention, the decorative article can stably exhibit an excellent appearance even in various environments. That is, the effect of the present invention is more remarkably exhibited when applied to a watch exterior part. The “watch exterior part” in this specification may be anything that can be visually recognized from the outside, and is not limited to the one exposed to the outside of the watch. (For example, a timepiece dial).

The color tone of the part where the decorative plating film is provided is, for example, a ^* is 7.0 or more and 15.0 or less in the chromaticity diagram of L ^* a ^* b ^* display defined by JIS Z 8729 And b ^* is preferably in the range of 15.0 to 27.0, a ^* is 8.0 to 13.0 and b ^* is 17.0 to 25.0. More preferably, it is in the range, and a ^* is in the range of 9.0 to 11.0 and b ^* is in the range of 18.0 to 23.0. Thereby, the aesthetic appearance of the decorative article is particularly excellent.

The color tone of the part where the decorative plating film is provided is, for example, L ^* is 75.0 or more and 89.0 or less in the chromaticity diagram of L ^* a ^* b ^* display defined by JIS Z 8729. It is preferable that L ^* is 78.0 or more and 88.0 or less, and L ^* is 82.0 or more and 87.0 or less. Thereby, the aesthetic appearance of the decorative article is particularly excellent.

<Clock>
Next, the timepiece of the present invention provided with the decorative product of the present invention as described above will be described.
FIG. 1 is a partial cross-sectional view showing a preferred embodiment of a timepiece (portable timepiece) of the present invention.
As shown in FIG. 1, a wristwatch (portable timepiece) 10 according to this embodiment includes a case (case) 22, a back cover 23, a bezel (edge) 24, and a glass plate 25. Further, in the case 22, a movement (not shown) (for example, a dial and one with hands) is accommodated.

A winding stem pipe 26 is fitted and fixed to the barrel 22, and a shaft portion 271 of a crown 27 is rotatably inserted into the winding stem pipe 26.
The body 22 and the bezel 24 are fixed by a plastic packing 28, and the bezel 24 and the glass plate 25 are fixed by a plastic packing 29.
Further, a back cover 23 is fitted (or screwed) to the barrel 22, and a ring-shaped rubber packing (back cover packing) 40 is inserted in a compressed state in these joint portions (seal portions) 50. Has been. With this configuration, the seal portion 50 is sealed in a liquid-tight manner, and a waterproof function is obtained.

A groove 272 is formed on the outer periphery of the shaft portion 271 of the crown 27, and a ring-shaped rubber packing (crown packing) 30 is fitted in the groove 272. The rubber packing 30 is in close contact with the inner peripheral surface of the winding stem pipe 26 and is compressed between the inner peripheral surface and the inner surface of the groove 272. With this configuration, the space between the crown 27 and the winding stem pipe 26 is liquid-tightly sealed, and a waterproof function is obtained. When the crown 27 is rotated, the rubber packing 30 rotates together with the shaft portion 271 and slides in the circumferential direction while being in close contact with the inner peripheral surface of the winding stem pipe 26.
The wristwatch 10 according to the present embodiment is a decorative product according to the present invention in which at least one of decorative items such as a bezel 24, a case 22, a crown 27, a back cover 23, and a watch band (especially, a watch exterior part) has been described above. It is composed of

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to these.
For example, at least a part of the surface of the decorative article is given corrosion resistance, weather resistance, water resistance, oil resistance, scratch resistance, abrasion resistance, discoloration resistance, etc. A coat layer (protective layer) or the like that improves the effect of scratches or the like may be formed. Such a coat layer may be removed when a decorative article is used.

Next, specific examples of the present invention will be described.
1. Preparation of a plating solution used for forming a plating film composed of an Au-Cu alloy (Example 1)
KAu (CN) ₂ , KCu (CN) ₂ , KCN, Na ₂ TeO ₄ were used, and using these, the gold content was 9.0 g / L, the copper content was 35.0 g / L, and tellurium. the content of 22 ppm, CN ^- content (free cyanide concentration) at 8.0 g / L of, pH to prepare a plating solution 10.2.
(Examples 2 to 6)
As shown in Table 1, a plating solution was prepared in the same manner as in Example 1 except that the composition was changed.

(Comparative Example 1)
A plating solution was prepared in the same manner as in Example 6 except that the tellurium oxoacid compound was not used and the tellurium was not used.
(Comparative Example 2)
A plating solution was prepared in the same manner as in Example 6 except that saccharin was used in place of the tellurium oxoacid compound.

(Comparative Example 3)
A plating solution was prepared in the same manner as in Example 6 except that saccharin, L-glutamic acid and 2-pyridinecarboxylic acid were used in place of the tellurium oxoacid compound.
Table 1 shows the conditions of the plating solutions (plating solutions used for forming a plating film composed of an Au—Cu alloy) in each Example and each Comparative Example.

2. Manufacture of decorative articles For each of the above Examples and Comparative Examples, the plating solution was prepared immediately after preparation (within 1 hour after preparation) and the same method as described above, and the environment was maintained at 35 ° C. for 30 days. Using the plating solution stored below (plating solution after long-term storage), a decorative article (watch case (back cover)) was produced by the method described below.
First, a base material main body having the shape of a watch case (back cover) was manufactured by casting using stainless steel (SUS444), and then necessary portions were cut and polished.

Next, the base body was washed. As washing | cleaning of the base-material main body, first, alkaline electrolytic degreasing was performed for 30 second, and then alkali immersion degreasing was performed for 30 second. Thereafter, neutralization was performed for 10 seconds, washing with water for 10 seconds, and washing with pure water for 10 seconds.
The substrate body cleaned as described above is subjected to flash plating using a gold plating solution prepared using KAu (CN) ₂ , thereby providing 24K gold plating with an average thickness of 0.1 μm. A layer was formed to obtain a substrate composed of a substrate body and a gold plating layer. The gold content in the gold plating solution was 8.0 g / L.

Next, a plating film made of an Au—Cu alloy was formed on the gold plating layer of the base material by electrolytic plating using the plating solutions prepared in the above Examples and Comparative Examples. Electrolytic plating was performed under the conditions of plating bath temperature: 60 ° C., applied voltage: 1.2 V, and plating treatment time: 12 minutes.
Next, using an oven, a heating process of heating to 380 ° C. (maximum temperature) was performed for 30 minutes, and then a cooling process was performed at a cooling rate of 25 ° C. to 0.024 ° C./second (heat treatment step). .

Next, the base material provided with the plating film subjected to the heat treatment step (heat treatment and cooling treatment) was immersed in a 69 wt% HNO ₃ aqueous solution at 25 ° C. for 3 seconds (acid treatment step).
Thereafter, washing with water was performed for 10 seconds, washing with pure water was performed for 10 seconds, and drying was performed to obtain a decorative article (watch case (back cover)). Thus, the average thickness of the plating film (plating film comprised with the Au-Cu type alloy) which the ornament obtained has was 2.5 micrometers.

3. Visual Appearance Evaluation Plating of each decorative product manufactured in each of the above Examples and Comparative Examples (a decorative product manufactured using a plating solution immediately after preparation and a decorative product manufactured using a plating solution after long-term storage) The site where the film was provided was visually observed.
(3-1) Evaluation of the color tone of the decorative product The color tone (including glossiness) of the portion provided with the plating film of each decorative product manufactured in each of the above Examples and Comparative Examples was determined based on the following three steps. And evaluated.
A: It has the target color tone (glossy pink).
B: It has a color tone slightly different from the target color tone (glossy pink).
C: It has a completely different color tone from the intended color tone (glossy pink).

(3-2) Evaluation of cloudiness in ornaments The occurrence of cloudiness in the parts provided with the plating films of the ornaments manufactured in the respective Examples and Comparative Examples was evaluated according to the following five-stage criteria. .
A: No cloudiness is observed.
B: Almost no clouding is observed.
C: The occurrence of cloudiness is slightly observed.
D: The occurrence of cloudiness is clearly recognized.
E: The occurrence of cloudiness is noticeable.

(3-3) Evaluation of color unevenness in ornaments Occurrence of color unevenness in a portion provided with a plating film of each ornament manufactured in each of the above examples and comparative examples, according to the following five-stage criteria: evaluated.
A: Color unevenness is not observed at all.
B: Almost no color unevenness is observed.
C: Slight color unevenness is observed.
D: The occurrence of uneven color is clearly recognized.
E: The occurrence of uneven color is noticeable.

(3-4) Comprehensive evaluation of external appearance The external appearance of the site | part in which the plating film of each ornament manufactured by each said Example and each comparative example was provided was evaluated according to the following five steps criteria.
A: Appearance is excellent.
B: Appearance is good.
C: Appearance is slightly poor.
D: Appearance defect.
E: Appearance is extremely poor.

4). Appearance evaluation by colorimeter (4-1) Evaluation of a ^* and b ^* Decorative products manufactured in the above Examples and Comparative Examples (Decorative products manufactured using a plating solution immediately after preparation, and long-term storage) For the decorative product manufactured using the subsequent plating solution), the chromaticity of the portion where the plating film was formed was measured using a chromaticity meter (CM-2022 manufactured by Minolta Co., Ltd.), and the following four criteria And evaluated.

A: In the chromaticity diagram of L ^* a ^* b ^* display specified by JIS Z 8729, a ^* is in the range of 9.0 to 11.0 and b ^* is in the range of 18.0 to 23.0. It is.
B: In the chromaticity diagram of L ^* a ^* b ^* display specified by JIS Z 8729, a ^* is in the range of 8.0 to 13.0 and b ^* is in the range of 17.0 to 25.0. (Except for the range of A).
C: In the chromaticity diagram of L ^* a ^* b ^* display specified by JIS Z 8729, a ^* is in the range of 7.0 to 15.0 and b ^* is in the range of 15.0 to 27.0. (Except for ranges A and B).
D: In the chromaticity diagram of L ^* a ^* b ^* display specified by JIS Z 8729, a ^* is 7.0 or more and 15.0 or less and b ^* is outside the range of 15.0 or more and 27.0 or less. It is.
As the light source of the colorimeter was a _{D 65} defined in JIS Z 8720, and measurements were taken at a viewing angle 2 °.

(4-2) Evaluation for L ^* Decorative products manufactured in the above Examples and Comparative Examples (manufactured using a plating solution immediately after preparation and a plating solution after long-term storage) For the decorative product), the chromaticity of the portion where the plating film was formed was measured using a chromaticity meter (CM-2022, manufactured by Minolta Co., Ltd.), and evaluated according to the following four criteria.

A: In the chromaticity diagram of L ^* a ^* b ^* display specified by JIS Z 8729, L ^* is in the range of 82.0 or more and 87.0 or less.
B: In the chromaticity diagram of L ^* a ^* b ^* display specified by JIS Z 8729, L ^* is in the range of 78.0 to 88.0 (excluding the range of A).
C: In the chromaticity diagram of L ^* a ^* b ^* display specified in JIS Z 8729, L ^* is within the range of 75.0 or more and 89.0 or less (excluding the ranges of A and B).
D: In the chromaticity diagram of L ^* a ^* b ^* display defined by JIS Z 8729, L ^* is outside the range of 75.0 or more and 89.0 or less.
As the light source of the colorimeter was a _{D 65} defined in JIS Z 8720, and measurements were taken at a viewing angle 2 °.

5). Evaluation of long-term stability of plating films and decorative products Decorative products manufactured in the above Examples and Comparative Examples (decorated products manufactured using a plating solution immediately after preparation, and manufactured using a plating solution after long-term storage) The decorative product is left to stand for 80 days in an environment of normal temperature (25 ° C.), normal pressure, and humidity 75% RH. The occurrence of color unevenness was evaluated according to the following five-step criteria.

A: No cloudiness or color unevenness is observed.
B: Generation of cloudiness and color unevenness is hardly observed.
C: Slightly cloudy or uneven color is observed.
D: Generation of cloudiness and color unevenness is clearly recognized.
E: Generation of cloudiness and color unevenness is noticeable.

6). Evaluation of Oxidation Resistance for Plating Films and Decorative Products Decorative products manufactured in the above Examples and Comparative Examples (Decorative products manufactured using a plating solution immediately after preparation, and manufactured using a plating solution after long-term storage) The decorative article) is left at 200 ° C. and atmospheric pressure for 8 hours, and then the part on which the plating film of the decorative article is formed is visually observed to cause occurrence of cloudiness and color unevenness. Evaluation was performed according to the five-stage criteria.

A: No cloudiness or color unevenness is observed.
B: Generation of cloudiness and color unevenness is hardly observed.
C: Slightly cloudy or uneven color is observed.
D: Generation of cloudiness and color unevenness is clearly recognized.
E: Generation of cloudiness and color unevenness is noticeable.

7). Evaluation of chemical resistance Artificial sweat was put in a desiccator and left at 45 ° C. for 12 hours. Thereafter, in the desiccator, the decorative articles manufactured in the above Examples and Comparative Examples (the decorative articles manufactured using the plating solution immediately after preparation and the decorative articles manufactured using the plating solution after long-term storage). And left at 45 ° C. At this time, each decorative article was arranged so as not to be immersed in artificial sweat. After 30 hours, each decorative article was taken out from the desiccator, and the portion where the plated film of the decorative article was formed was visually observed, and the occurrence of cloudiness and color unevenness was evaluated according to the following five-stage criteria.

A: No cloudiness or color unevenness is observed.
B: Generation of cloudiness and color unevenness is hardly observed.
C: Slightly cloudy or uneven color is observed.
D: Generation of cloudiness and color unevenness is clearly recognized.
E: Generation of cloudiness and color unevenness is noticeable.
These results are shown in Table 2.

As can be seen from Table 2, in the present invention, it is possible to stably produce a decorative article that has excellent aesthetic appearance, in particular, a glossy pink appearance, in which the occurrence of uneven color and cloudiness is prevented. I was able to. Moreover, in the present invention, the long-term stability, oxidation resistance, and chemical resistance of the manufactured decorative article were also excellent.
On the other hand, satisfactory results were not obtained in the comparative example.

Further, a wristwatch as shown in FIG. 1 was assembled using the decorative articles manufactured in the respective Examples and Comparative Examples. When these wristwatches were evaluated in the same manner as described above, the same results as described above were obtained.
In addition, when a decorative article is repeatedly produced over a long period of time using the plating solution according to the present invention, the tellurium content, etc. is determined by measurement using an atomic absorption photometer, inductively coupled plasma emission spectrometer (ICP) It was possible to easily determine the degree of decrease in the plating solution, and to appropriately determine the timing of replacement and preparation of the plating solution. In Comparative Examples 2 and 3, the degree of decrease in the organic substance is appropriately determined. I couldn't.

  DESCRIPTION OF SYMBOLS 10 ... Wristwatch (portable watch) 22 ... Body (case) 23 ... Back cover 24 ... Bezel (edge) 25 ... Glass plate 26 ... Winding pipe 27 ... Crown 271 ... Shaft part 272 ... Groove 28 ... Plastic packing 29 ... Plastic Packing 30 ... Rubber packing (Crown packing) 40 ... Rubber packing (back cover packing) 50 ... Junction (seal)

Claims (8)

A plating solution containing gold ions and copper ions,
A plating solution comprising an oxoacid compound of tellurium. The gold content in the plating solution is 8.0 g / L or more and 10.0 g / L or less,
The plating solution according to claim 1, wherein the content of copper in the plating solution is 30 g / L or more and 40 g / L or less.   The plating solution according to claim 1 or 2, wherein the tellurium content in the plating solution is 10 ppm or more and 1000 ppm or less.   The plating solution according to any one of claims 1 to 3, which has a hydrogen ion index (pH) of 9.7 or more and 11.0 or less.   A plating film formed using the plating solution according to claim 1.   A decorative article comprising the plating film according to claim 5.   The decorative article according to claim 6, wherein the decorative article is a watch exterior part.   A timepiece comprising the decorative article according to claim 6 or 7.

Images