JPH05106062A - Outer ornament parts for watch - Google Patents

Abstract

PURPOSE:To form a coating layer having a color tone extremely close to that of gold by forming a gold-colored hard compound layer composed essentially of titanium nitride on the surface and further forming a gold-colored coating layer of gold-chromium alloy under specific conditions on the above. CONSTITUTION:A work is cleaned with an organic solvent, and a titanium nitride film is formed on the work in an ion plating apparatus. Subsequently, in the same apparatus, a gold-chromium alloy having a chromium content of 0.05-<5wt.% based on gold content is evaporated by means of electron beam heating, by which a gold-colored coating layer of gold-chromium alloy is formed. The resulting work has a color tone equal to that of gold. Because thin thickness suffices for the film thickness of the gold-chromium alloy, the increase in cost is slight. Even if the substrate of this gold-colored coating layer is allowed to appear because of wear, the titanium nitride film on the substrate has a color tone similar to that of gold and, as a result, the local exposure is not distinct.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a watch exterior part such as a gold watch case and a metal band.

[0002]

2. Description of the Related Art Outer parts such as watch cases and metal bands are usually made of stainless steel, and the surface is usually exposed as it is, but gold has a beautiful color tone and corrosion resistance. Is especially good
A coating layer is often formed on the surface of stainless steel or the like by gold plating or gold plating. The thickness of the gold coating layer may be 0.1 μm or less from the viewpoint of exhibiting a golden color in the case of jewelry or the like where corrosion resistance and abrasion resistance are not required so much. , At least 3 because it requires high corrosion resistance to water and wear resistance to withstand long-term use.
μm, ideally 5 μm or more is required. However, gold is a very expensive metal, so there is a limit to using it for watch exterior parts that require high corrosion resistance and wear resistance, except for some high-grade parts, and it is cheaper and has sufficient functions. It has been desired to develop a gold-colored coating layer that exhibits the above properties.

Recently, a gold-colored hard coating mainly composed of titanium nitride, tantalum nitride, tantalum carbide, zircon nitride, hafnium nitride or the like is formed by physical vapor deposition (PVD) such as ion plating or sputtering or chemical vapor deposition (CVD). As a result, an inexpensive and functionally excellent gold coating layer has come into practical use.

[0004]

However, although these coating layers are gold-colored at first glance, they are clearly different from the color tone of gold itself and do not show the color tone specific to gold. Further, in the ion plating method, it is possible to coat a large area, and the coating layer mainly composed of titanium nitride can introduce carbon or oxygen to bring it closer to the color tone of gold, but the reflectance is still However, there is a limit in applying such a golden hard coating to watch exterior parts in any case.

[0005] Therefore, an object of the present invention is to provide at low cost a timepiece exterior component having a coating layer excellent in corrosion resistance and wear resistance and having a color tone extremely close to that of gold.

[0006]

In order to achieve the above object, the present invention forms a gold-colored hard compound layer mainly composed of titanium nitride on the surface of a watch exterior part, and further,
A gold-colored coating layer made of a gold-chromium alloy having a chromium content of 0.05% by weight or more and less than 5% by weight of gold is formed.

Here, it is important to use a gold-chromium alloy, and instead of the gold-chromium alloy, pure gold was deposited on the gold-colored hard compound layer mainly composed of titanium nitride by an ion plating method or the like. In this case, there is a problem in adhesion and wear resistance, addition of 0.05% by weight or more of chromium significantly improves adhesion and wear resistance, and the color tone is almost the same as that of pure gold or gold alloy of 24 to 14K, which is beautiful. It has a golden color. However, if chromium is added in an amount of 5% by weight or more, the whiteness becomes stronger and the color tone becomes different from that of gold, and the object cannot be achieved.

[0008]

Example 1 The present invention will be specifically described based on the following examples. A stainless steel watch band is cleaned with an organic solvent and placed in the ion plating device. After decompressing the inside of the ion plating device to 2 × 10 ⁻⁵ Torr, argon gas was introduced up to a pressure of 2 × 10 ⁻² Torr, and a DC voltage of −500 V was applied to the band to be treated to perform the bombarding treatment. To do. Next, titanium is evaporated by electron beam heating, and a titanium film is formed by ionizing with a thermionic emission filament and an ionization electrode in the ion plating device. Nitrogen gas is evaporated under a pressure of 5 × 10 ⁻⁴ Torr while titanium is evaporated. To form a titanium nitride film. Next, the gold-chromium alloy was vaporized by electron beam heating in the same apparatus, and ionized by the thermionic emission filament and the ionization electrode to give 0.1 μm.
A gold coating layer of 0.05% by weight chromium alloy.

The band thus obtained has a beautiful color tone equivalent to that of gold, and since the gold-colored coating layer made of a gold-chromium alloy has an extremely thin film thickness, it is possible to use only the conventional titanium nitride film. Compared with this, the cost increase is very slight, and an inexpensive band can be obtained. Since the gold coating layer is thin, the underlying layer may be exposed by abrasion, but the titanium nitride coating on the underlying layer is hard and has a color tone similar to that of gold, so it is locally exposed. But it is hardly noticeable. Furthermore, by coating a gold-colored layer such as gold or gold alloy on the gold-chromium alloy gold-colored coating layer by wet plating, it is possible to provide a watch exterior component having a wide range of gold-colored tones. become.

[0010]

[Example 2] A timepiece case made of brass and plated with nickel and chromium is washed with an organic solvent and placed in an ion plating apparatus. Then, after performing a bombarding process as in Example 1, a titanium film is formed. Next, while evaporating titanium, nitrogen gas is added to 5 × 10 5.
^-4 Torr pressure is introduced to form a titanium nitride film, and then nitrogen gas and acetylene gas are supplied at a flow rate ratio of 99: 1.
To 5 × 10 ⁻⁴ Torr to form a titanium carbonitride film.
Then, in the same manner as in Example 1, a gold coating layer of 0.3 μm of gold-4% by weight chromium alloy is formed. This gave a beautifully colored watch case with a weak white tint of gold. In this watch case, since the amount of chromium in the gold-colored coating layer made of the gold-chromium alloy in the upper layer is larger than that in the band of Example 1, the wear resistance is high and it is hard to wear, but even if it is locally worn, Since the titanium nitride film has a color tone similar to that of gold, the wear is not noticeable in Example 1.
The same as for the band.

[0011]

Example 3 A titanium alloy watch case is washed with an organic solvent and placed in an ion plating apparatus. Then, the same bombarding treatment as in Example 1 was performed to evaporate titanium while maintaining the nitrogen gas at a pressure of 5 × 10 ⁻⁴ Torr,
It is ionized to form a titanium nitride film. Subsequently, a gold coating layer of 0.5 μm of gold-3 wt% chromium alloy is formed by the same method.

The watch case thus obtained has a beautiful color tone of a very pale whitish gold color. Conventionally, it is difficult to plate titanium alloys, and only gold plating has been put into practical use. However, the adhesiveness is not sufficient, and not only is it necessary to confirm the adhesiveness by a taping test, but since there is a problem with the adhesiveness, thickening cannot be performed, and problems with wear resistance due to long-term use are overcome. ing. On the other hand, according to this embodiment, the wear resistance is excellent,
Can withstand long-term use.

In the above embodiments, the material is stainless steel, brass, titanium alloy, but other than this, it can be applied to all metals or alloys used for exterior parts such as copper alloy and aluminum alloy. Further, if attention is paid to heat resistance, the same effect can be obtained even when applied to ceramics or plastics other than metal. In addition, not only the ion plating method but also sputtering, vacuum deposition, and CVD are used for the gold-colored hard compound layer mainly composed of titanium nitride of the intermediate layer and the gold-colored coating layer of the gold-chromium alloy for the surface layer.
It can also be formed by the following. Then, wet plating may be performed, a hard transparent film may be formed by PVD, or an organic film may be formed by painting or printing on the gold-colored coating layer of the gold-chromium alloy.

[0014]

As described above, according to the present invention, a gold-colored hard compound layer containing titanium nitride as a main component is formed on the surface of a watch exterior component, and a chromium content of 0.
A gold-colored coating layer made of a gold-chromium alloy in an amount of 05% by weight or more and less than 5% by weight is formed, and therefore, a watch exterior part having a coating layer excellent in corrosion resistance and wear resistance and having a color tone extremely close to that of gold on the surface. Can be provided at low cost.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location G04B 37/22 M 8201-2F (72) Inventor Yasuhiro Masumoto 1-15-4 Ueno, Taito-ku, Tokyo No. Sailor Fountain Pen Co., Ltd. (72) Inventor Seiji Seiji 1-15-4 Ueno, Taito-ku, Tokyo Sailor Fountain Pen Co., Ltd. (72) Inventor Yasushi Kawashita 3-35 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Issue Shinko Seiki Co., Ltd. (72) Inventor Masahiro Tsuchimoto 3-135 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Shinko Seiki Co., Ltd. (72) Inventor Toshihiko Amase 3-chome Takatsuka, Nishi-ku, Kobe-shi, Hyogo 1-35 Shinko Seiki Co., Ltd. (72) Inventor Hideo Nagamitsu 3-28-15 Hatchobori, Chuo-ku, Tokyo Hibiya Kagashi Building Co., Ltd. (72) Inventor Tetsuji Taniwaki 3-8-15 Hatchobori, Chuo-ku, Kyoto Hibiya Riverside Building Higashi Seisakusho Co., Ltd. (72) Inventor Tsuneo Tomihara 3-28-15 Hatchobori, Chuo-ku, Tokyo Hibiya Riverside Building Higashi Seisakusho Co., Ltd.

Claims (1)

[Claims] 1. A gold-colored hard compound layer containing titanium nitride as a main component is formed on the surface, and a gold-chromium alloy having a chromium content of 0.05% by weight or more and less than 5% by weight with respect to gold is further formed thereon. A watch exterior part, wherein a gold coating layer is formed.