JP2595168B2 - Watch exterior parts and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external part of a timepiece and a method of manufacturing the same, and more particularly, to a watch having at least a part of its surface in a non- (semi) glossy milky color similar to a pearl shine. The present invention relates to a watch exterior part that gives a high-quality texture with excellent decorativeness and a method for manufacturing the same.

[0002]

2. Description of the Related Art Timepieces are required to have not only an original function of accurately ticking time, but also a function as an interior decoration or an accessory. The parts of the watch include a movement that is a drive system, a watch, a crown, a dial, a dial receiving ring, an hour hand, a minute hand, a second hand, a back cover, a back cover packing, a watch band (for a wrist watch), and a chain (a pendant watch). And in the case of pocket watches).

[0003] The shape, color tone,
Various kinds of decorative effects are pursued by appropriately selecting the gloss and by appropriately combining them. For example, an exterior part of a watch that has a warm silver-white surface is known. Exterior parts having such a color tone have long been manufactured using a precious metal such as platinum, a platinum-based gold alloy, or silver as a material of the exterior part itself.

However, all of the above-mentioned noble metals are expensive. For this reason, recently, the main body of the exterior component has been manufactured from an inexpensive material such as stainless steel or brass, and the main body is electroplated with the above-described noble metal to produce the above-described color tone. For example, when the above color tone is expressed by silver, a bright silver plating layer having a desired thickness is formed on the surface of the exterior component body using a cyan plating bath. When the surface of the exterior component body is smooth, the plating layer of electrodeposited silver by the cyan bath has a silver-white shiny specular gloss surface. Since silver is able to blackening by reacting with sulfide in air, typically, on the surface of the glossy silver plating layer, for example, SiO ₂ thin film CVD, such as by PVD or sol-gel method, Al ₂ O ₃ Transparent coating such as forming a thin film, silver discoloration inhibitor treatment, or rhodium plating with a thickness (0.1 to 0.2 μm) that does not impair the silver plating color Measures have been taken to prevent alteration.

[0005] Some consumers not only have a silver-white specular gloss surface but also a matte silver-white non-gloss surface or semi-gloss surface, and a glossy surface and a non-gloss surface / semi-gloss surface. There are also voices requesting exterior parts having a matched patterned surface. When the entire surface of the exterior component body is to be a silver-white non-glossy surface or a semi-glossy surface, for example, sandblasting is performed on the surface of the exterior component body to make the surface a matte surface with a desired roughness, The bright silver plating described above may be performed thereon. When the matte surface of the exterior component body is a rough surface with severe irregularities, a non-glossy surface is obtained, and when the matte surface is small, a semi-glossy surface is obtained.

[0006]

However, according to the above-mentioned method, the surface of the exterior component can be made to have a matte surface or a semi-glossy surface only after the surface of the exterior component has a matte surface having a desired roughness. Therefore, when manufacturing an exterior component having a color tone in which a non- (semi) glossy surface and a glossy surface are combined in a pattern, a desired rough surface is preliminarily applied to the surface of the exterior component main body in accordance with the intended pattern pattern. It is necessary to form a rough surface and a non-rough surface pattern.

When the entire surface of the exterior component is to be silver-white, the exterior component body having the above surface condition may be subjected to bright silver plating. The rough surface becomes a silver-white non- (semi) glossy surface,
The non-rough surface portion becomes a silver-white mirror surface, and a target silver-white pattern is obtained. However, for example, when an exterior component having a pattern pattern in which a silver-white non- (semi) glossy surface is combined with a mirror surface of another color (for example, pink tone) is to be manufactured, first, the surface of the exterior component body is required. Is mirror-finished, and the mirror-finished portion is masked. Then, in this state, after the surface other than the mask portion is roughened, the mask is peeled off, and the entire surface is subjected to bright silver plating.
Next, after masking the roughened portion, a plating layer having a desired color tone is formed on the mirror surface portion, and finally, the mask is peeled off.

However, such an operation is very complicated, and at the same time, it is necessary to select an appropriate mask material according to each plating. In addition, when the pattern is a simple pattern, plating can be performed in combination with a desired color tone by the above method.However, when the pattern becomes complicated, reliable masking of each pattern becomes extremely difficult. In the obtained plating layer, the color tones may overlap each other at the boundaries of the respective pattern patterns, and the initially designed color tone pattern may not be achieved.

The present invention solves the above-mentioned problem, and even if the surface of the exterior component body to be used is in a mirror-finished state, at least a part of the surface is not subjected to a roughening treatment, and at least a part of the surface is made of non-white non- ( It is an object of the present invention to provide a watch exterior part having a semi-glossy surface and a method of manufacturing the same.

In order to achieve the above object, according to the present invention, a watch exterior component body having a smooth surface, and at least a part of the surface of the exterior component body are covered with methanesulfo.
Silver acid as a silver source and potassium iodide as a complexing agent
And was observed with a scanning electron microscope.
The present invention provides an external part of a timepiece characterized by comprising a silver plating layer having a fine uneven surface made of electrodeposited silver having a grain size of 0.1 to 2 μm, and having a smooth surface. such to watch exterior parts, silver supply silver methanesulfonate
As a source, electroplating is performed using a plating bath containing potassium iodide as a complexing agent , and at least a part of the surface of the exterior component body has a large size of granular protrusions as observed by a scanning electron microscope.
A method of manufacturing an external part of a timepiece is provided, wherein a silver plating layer having a fine uneven surface made of electrodeposited silver having a thickness of 0.1 to 2 μm is formed.

The exterior component of the present invention is made of a relatively inexpensive material such as stainless steel or brass, and is provided on the entire surface or a partial surface of the exterior component body having a mirror-like smooth surface. It is essential that a silver plating layer described later be directly formed. Further, when a transparent alumina thin film is formed on the surface of the silver plating layer by, for example, the CVD method, the silver plating layer can be effectively prevented from being reacted with sulfide and from being scratched.

The silver plating layer, unlike the conventional bright silver plating layer, is formed by depositing electrodeposited silver having a particle size of 0.1 to 2 μm. Therefore, the surface of the layer is a fine uneven surface composed of electrodeposited silver having a particle size of 0.1 to 2 μm. Therefore, the surface of the silver plating layer becomes a non- (semi) glossy surface. In addition, the color tone is subtly changed depending on the particle size of the deposited silver.

Although the thickness of the silver plating layer is not particularly limited,
If the thickness is too small, the sense of transparency increases, making it difficult to obtain the above-mentioned color tone. If the thickness is too large, it becomes uneconomical, so the thickness may be about 3 to 30 μm. This silver plating layer
It can be formed by electroplating using a silver methanesulfonate-potassium iodide plating bath which is an acidic silver plating bath containing no cyanide.

As the above-mentioned plating bath, for example,
"Dyne Silver AG-" manufactured by Daiwa Chemical Industry Co., Ltd.
PL30 ″. When N- (3-hydroxy-1-butylidene) -p-sulfanilic acid is added to this plating bath in an appropriate amount, the grain size of the deposited silver becomes finer. Since the color tone of the silver plating layer becomes more pearl-like, it is preferable.

In the electroplating using the plating bath, the exterior component body is immersed in the plating bath as it is, without performing a matting treatment on the surface of the exterior component body, and electroplating is performed. The surface can be brought to the desired non-semi-gloss state. Also, when a part of the surface of the exterior component is to be a mirror glossy surface of another color, first, the entire surface of the exterior component body having a mirror-like smooth surface,
After coating with the plating layer of the above-mentioned color, a portion to be made a mirror glossy surface is masked, and electroplating is performed using the plating bath as it is to form a silver plating layer of a desired thickness, and the mask is peeled off. The mirror glossy surface of another color may be exposed.

[0016]

【Example】

Example 1 Dyne Silver AGM-5 (manufactured by Daiwa Kasei Laboratory Co., Ltd.)
Ag ⁺ concentration: 30 g / l) 200 g / l, Dyne Silver AGI (manufactured by Daiwa Kasei Laboratories) 500 g / l, Dyne Silver AGH (manufactured by Daiwa Kasei Laboratories) 25 g
/ L, pH 7, bath temperature of 40-50 ° C.

In this plating bath, a stainless steel watch block band was used as a cathode, a silver plate having a purity of 99.99% was used as an anode, and electroplating was performed at a current density of 1 A / dm ^2. Was. The surface of the obtained block band was a milky white non- (semi) glossy surface and exhibited a pearl-like shine. The metal structure on the surface of the block band was photographed with a scanning electron microscope (3000 times magnification). The result is shown in FIG.

For comparison, the same type of watch block band was subjected to bright silver plating under the following conditions. That is, K
Ag (CN) ₂ 90 g / l, free KCN 100 g / l, K
A plating bath of 15 g / l ₂ CO ₃ , Nissin Bright (bright material manufactured by Nisshinsei Co., Ltd.), 10 ml / l, and a bath temperature of 15 to 25 ° C. was constructed. A silver plate having a purity of 99.99% was used for the anode, and electroplating was performed at a current density of 1.5 A / dm ² .

The surface of the obtained block band was a glittering silver-white glossy mirror surface. The metal structure on the surface of the block band was also photographed with a scanning electron microscope (3000 times magnification). The result is shown in FIG. As is clear from the electron micrographs of FIGS. 1 and 2, in the block band of the present invention, the electrodeposited silver of the silver plating layer on the surface has a fine grain shape. The surface is not a grain structure but a smooth surface. Therefore, it is considered that the plating layer shown in FIG. 2 has a specular gloss, and the plating layer shown in FIG.

Example 2 A plating bath having the following composition was prepared. That is, KAu
(CN) ₂ 15 g / l, KCu (CN) ₂ 125 g / l, free KCN ₂₀ g / l, K ₂ CO ₃ 15 g / l, Na ₂ H
PO ₄ 15 g / l, K ₂ Cd (CN) ₄ 1 g / l, bath temperature 5
0-65 ° C.

In this plating bath, a watch block band of the same type as that used in Example 1 was used as a cathode, a platinum-plated titanium plate was used as an anode, and a current density of 1 was used.
It was subjected to electroplating in the A / dm ^2. The entire surface of the block band was made of an Au-Cu-Cd alloy, and was covered with a plating layer having a so-called pink gold color.

Then, a fluorocarbon mask MA-1 (trade name, manufactured by Koto Sangyo Co., Ltd.) is applied in a belt shape on the outer surface of each body piece of the block band, and a pink gold layer is masked. A silver plating layer was formed on the remaining exposed surface of the block band using a plating bath. The masking of the obtained block band was peeled off. A gorgeous mirror band of pink gold runs along the center line of the main body piece, and the remaining surface of the main body piece and the surface of the connecting piece have a milky color tone similar to the shine of pearls, overflowing with a very noble feeling A watch band with a different color was obtained.

[0023]

As is clear from the above description, in the external part of the timepiece of the present invention, the silver plating layer formed on the surface has a particle size of 0.1.
Since it is composed of electrodeposited silver having a thickness of 1 to 2 μm, its surface becomes a milky white non- (semi) glossy surface, giving a calm impression compared to the mirror gloss of conventional glossy silver.

Further, in the present invention, the above-mentioned effects can be obtained without previously roughening the surface of the exterior component main body, so that the manufacturing process is shortened and is industrially useful. Further, the combination of the milky white non- (semi) glossy surface and the mirror gloss of other colors can be easily performed, so that it is possible to provide an exterior part of a timepiece having a decorative property which has not existed conventionally. .

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph showing a metal structure of a silver plating layer on the surface of an exterior component of the present invention.

FIG. 2 is a scanning electron micrograph showing the metal structure of a conventional bright silver plating layer.

Claims (2)

(57) [Claims] 1. A watch exterior component body having a smooth surface and a methane
Using silver sulfonate as a silver source and potassium iodide as a complexing agent
The plating bath is used for electrodeposition and observed with a scanning electron microscope.
An external part for a timepiece, comprising a silver plating layer having a fine uneven surface made of electrodeposited silver having a grain size of 0.1 to 2 μm when formed . To 2. A smooth surface timepiece exterior parts, a silver methanesulfonate and silver source, and a complexing agent of potassium iodide
Electroplating was performed using a plating bath containing the components, and at least a part of the surface of the exterior component body was observed with a scanning electron microscope.
A method of manufacturing an external part of a timepiece, comprising forming a silver plating layer having fine irregularities made of electrodeposited silver having a grain size of 0.1 to 2 μm.