JPS5945754B2 - Exterior parts for watches - Google Patents

Description

Detailed Description of the Invention The present invention uses brass or nickel silver that has excellent stampability and cutting workability, and is coated with titanium nitride and exhibits a golden color with excellent adhesion and corrosion resistance using an ion-blating method. Regarding exterior parts for watches.

BACKGROUND ART Conventionally, brass materials, which are superior in punchability and machinability and are cheaper than stainless steel materials, have been used externally for watch exterior parts whose surfaces are wet-plated.

However, in recent years, to replace the wet plating method, a vapor phase plating method that is free from pollution, has excellent corrosion resistance, and has excellent adhesion has attracted attention and has been developed.

When a titanium nitride film is directly formed on brass material using the ion blating method in gas phase plating, dezincing phenomenon occurs in a high vacuum atmosphere due to the temperature rise inside the persier, and the surface of the brass material becomes discolored. The corrosion resistance of the surface deteriorated, and as a result, the appearance as a watch exterior could not be satisfied. Also, unlike titanium nitride ion brating on stainless steel materials, which have excellent corrosion resistance,
Since the corrosion resistance of the copper alloy material itself is poor, it has been difficult to satisfy the corrosion resistance as a watch exterior part due to the presence of pinholes in the titanium nitride coating. In order to improve the corrosion resistance, it is recognized that corrosion resistance is improved by applying a coating of oxide (silica, zinc, cadmium) to the base plating layer, but due to the difference in thermal expansion coefficient between these base plating layers and the titanium nitride coating, ion blating operation is required. As the substrate temperature decreased after completion of the process, a peeling phenomenon occurred between the base plating layer and the titanium nitride layer, making it unusable as a watch exterior part. Also, the method of using chromium as the base plating and applying ion blasting on top of it is as follows:
Adhesion is obtained, but there is a problem with corrosion resistance. In order to solve the above-mentioned drawbacks, the present invention uses a watch exterior part made of brass or nickel silver material, forms nickel as a base layer on the surface of the exterior part, forms a chromium layer directly on the nickel layer, and ionizes By coating the chromium layer with a titanium nitride film exhibiting a golden color using the brating method, peeling phenomenon between the base nickel layer and the titanium nitride layer is prevented, and by directly applying nickel-chromium, the brass Furthermore, the corrosion resistance of the nickel silver material has been improved, making it possible to use it for watch exterior parts that exhibit a golden-colored titanium nitride coating using the ion-blating method.

It is something. The thickness of the nickel layer is within a commonly known range of 3μ to 10μ, with 6μ being optimal economically or functionally. Also, the chromium layer has a thickness of 0.2 μ to 0.3
Although μ is within a common sense range, the effects of corrosion resistance and adhesion remain unchanged even if it is expanded to a range of 0.1 μ to 0.5 μ. below,
Examples of the present invention will be described.

First Example A nickel layer of about 6 microns was formed on a watch case made of brass material by electric or electroless plating, and
By electroplating, the chromium layer as the second layer is deposited by approximately 0.3
Micron was applied.

A brass material watch case was set in the Persian of the ion plating device, and Ar2. The surface of the case was cleaned by performing a thorough cleaning at 0×10 −2 T0rr and an applied voltage of 2.0 KV. Next, A
Exhaust the r gas and reduce the inside of the Persian to 1×10-5T0r.
After returning to r, Ar gas and N2 gas were introduced again, and the TOtal pressure was set to 2.0 x 10-2T0rr.
A voltage (3.0 K, 50 mA) was applied to generate plasma, and titanium metal was heated and evaporated using a board heating method, and titanium nitride (4 microns) was plated. The figure shows the structure of a watch case coating formed by the above method.

1 is a brass case, 2 is a nickel layer, 3 is a chrome layer, 4
is an ion plating layer of titanium nitride.

The brass material watch case treated using this method was subjected to a salt spray test (140 hours in 5% sodium chloride solution), an artificial sweat corrosion resistance test (96 hours), and a bending test (180 degrees).
All of the above test results fully satisfied the corrosion resistance and adhesion properties as a watch case.

Second Example A watch case made of nickel silver material was treated in the same manner as in the first example.

In this case as well, the corrosion resistance and adhesion of the watch case were satisfied. In addition to the ion plating gas atmosphere (argon-nitrogen mixed gas) used in the first embodiment,
The same results as in the first example were obtained with ammonia gas, hydrogen-nitrogen mixed gas, xenon-nitrogen mixed gas, neon-nitrogen mixed gas, and helium-nitrogen mixed gas.

In addition, although a watch case is described as an example, the present invention can also be applied to exterior parts that come into direct contact with human skin, such as bezels, push buttons, rear covers, bands, etc., to ensure durability. It is also clear that it enhances the decorative effect.

As mentioned above, the conventional method of underplating with either nickel or chromium and applying ion grating on top of it had defects in terms of adhesion and corrosion resistance. A nickel layer is formed as a base on the surface of the nickel silver material, a chromium layer is formed directly above it, and a titanium nitride film is formed using an ion plating method to provide both corrosion resistance and abrasion resistance, as well as decoration. It became possible to have a certain effect.

[Brief explanation of the drawing]

The figure is a sectional view showing an embodiment of the present invention. 1... Brass material case, 2... Nickel plating layer, 3... Chrome plating layer, 4...
...Titanium nitride ion plating layer.

Claims (1)

[Claims] 1 Using a watch exterior part made of brass or nickel silver material, nickel is formed as a base layer on the surface of the exterior part, and a chromium layer is formed directly on the nickel layer, and the chromium layer is coated by an ion plating method. An exterior part for a watch characterized by having a titanium nitride coating that is golden in color.