JPH07243022A - Production of ion-plated timepiece parts and ornament - Google Patents

Abstract

PURPOSE:To form an abrasion and shock resistant thin film having a natural gold color by stepwise reducing the amt. of gaseous nitrogen fed at the time of forming a golden thin TiN film by ion plating or other method on the surface of metallic stock. CONSTITUTION:When a golden TiN film is formed by ion plating or other method on the surface of the case of a wrist watch made of stainless steel as stock, a vapor-deposited layer of hard metal Ti is first formed in 0.1mum thickness on the surface of the metallic stock and yellowish-green TiN is deposited in 0.5mum thickness by feeding 90cc/min gaseous nitrogen. The amt. of gaseous nitrogen fed is then continuously reduced from 150cc/min to 100cc/ min and the objective thin TiN film having a natural gold color and excellent in scratch resistance is formed in 0.1mum thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing golden titanium nitride suitable for timepiece parts and ornaments.

[0002]

2. Description of the Related Art Conventionally, for plating of watch parts, that is, cases, case backs, glass edges, crowns, bands, etc.
Wet plating and dry plating have been used. Wet plating forms a film of gold or a gold alloy, but has the drawback that it has a low hardness and lacks wear resistance, and expensive gold must be applied thickly. On the other hand, dry plating usually uses ion plating or spatter and has high wear resistance due to its high hardness, but it has a limit as an ornament because it has a yellowish green color unlike natural gold. It was In order to modify this color tone and bring it closer to a natural gold color, a mixed film of titanium nitride and gold is formed, and nitrogen gas is increased stepwise in accordance with the evaporation of metallic titanium as a raw material to form a different color layer. A method has been proposed in which a unique coloring effect is exhibited by stacking layers in a multi-layered manner.

[0003]

However, in the conventional method, the mixed film of gold and titanium nitride does not become a natural golden color unless the ratio of gold in both of them is increased, so that it is still expensive. There are drawbacks. In the case of the multi-layer stacking, the color tone is close to that of natural gold but still insufficient, and its modification is desired. Moreover, since the hardness gradually increases from the lower layer to the outermost layer and only the outermost layer is hard, there is a drawback that it is dented or scratched by a rubbing impact.

Therefore, a first object of the present invention is to form a natural gold color film, a second object is to reduce the proportion of gold to make it inexpensive, and a third object is to provide a rubbing impact. It is to obtain a strong film formation.

[0005]

In order to solve the drawbacks of the latter multi-layer stacking, the present invention reduces the amount of nitrogen gas from the initial value stepwise or continuously to reduce the known amount of nitrogen gas from the initial value. It is possible to make it closer to a natural gold color compared to the method of increasing the amount, and hard titanium nitride is formed at the beginning or in the middle of the film formation, and then the amount of nitrogen gas is gradually reduced or increased to form the film. As a result, the color tone of the surface is natural gold, and since hard titanium nitride is inserted in the lower layer, it is possible to manufacture watch parts and ornaments that are resistant to scratches and have a gold color that is difficult to dent.

[0006]

The ion plating evaporates metallic titanium to deposit metallic titanium on the substrate, and then supplies nitrogen gas to the vacuum chamber to react metallic titanium and nitrogen to synthesize gold titanium nitride and deposit it on the substrate. The ratio of titanium to nitrogen is 1 to 1, but a difference in the ratio causes a slight difference in color tone. Metallic titanium is white silver, but Ti
N is yellow green and TiN ₂ is yellow red. This TiN and T
intermediate state for example a pair 1.2 of iN ₂ is considered, the color tone changes to reddish direction. It is known that when the ratio is changed stepwise or continuously, multiple layers having different colors are formed and a unique coloring effect is produced. It is considered that the coloring effect is that a new unique color different from the original color is newly created due to the interference of the colors in the upper and lower layers. Here, it became clear that there was a difference in color tone between the case of increasing the nitrogen gas and the case of decreasing it.

That is, it was revealed that the color tone of the case of increasing and the case of decreasing were close to natural gold in the latter case. Since this is a color due to the interference of light and is not considered to be the original color itself, there is a subtle difference in color tone due to the difference in the layer order when the ratio of Ti and N increases and decreases, It is considered that the case of reducing the nitrogen gas as in the present invention is superior, but the details are unknown.

Next, regarding the scratch resistance, the hardness of metallic titanium and Ti is Hv80, and the hardness of TiN is Hv170.
0, the hardness of TiN 0.8 is Hv320, and TiN is the hardest. Therefore, by constructing this hard layer of TiN in the lower layer, the dent resistance becomes stronger, and when comparing the case where the hard lower layer that becomes a barrier is constructed and the case where it is not constructed, the hard lower layer is affected by the external force. It is clear that the former is more advantageous because it never happens.

[0009]

The present invention will be described in detail below with reference to examples. (Example 1) A wristwatch case made of stainless steel SUS304 was inserted into an ion plating device to deposit gold titanium nitride. The ion plating apparatus is a hollow cathode type and the film forming conditions are as follows.

HCD current voltage 200A 24V Substrate bias 20W Gas and its flow rate Nitrogen 1-150 CC / min The evaporation rate of titanium metal was kept constant and the nitrogen gas flow rate was changed.

The order of film formation is as follows. First, titanium metal is deposited in a thickness of 0.1 μ without supplying nitrogen gas, then 90 CC of nitrogen gas is supplied to deposit 0.5 μ in thickness, and further the amount of nitrogen gas is changed. Sequentially 80, 70 and 60 CC / min, part 3
The operation was terminated with a total layer thickness of 0.1 μ. The color tone obtained was a natural golden color with a slight whitish tint. Indentation scratches were observed in the surface scratch test and were insufficient.

Example 2 Using the same sample and method as in Example 1, the amount of nitrogen gas was continuously reduced from 150 CC / min to 100 CC, and the thickness of the continuously reduced portion was set to 0.1 μ. The obtained color tone was a slightly reddish natural gold color, and was an excellent color closer to a more natural gold color than the color tone when the amount of nitrogen gas was continuously increased. Indentation scratches were observed in the surface scratch test and were insufficient.

Example 3 On the same sample as in Example 1, 0.1 μm of metallic titanium was deposited, and then hard titanium nitride TiN was used.
TiN was deposited at a thickness of 0.5 μm by supplying a nitrogen gas amount of 90 CC / min under a synthesis condition of (1: 1 ratio). Since the color tone is yellowish green, the nitrogen gas amount is changed from 150 CC / min to 10
It was continuously reduced to 0 CC / min, and the thickness of the continuously reduced portion was set to 0.1 μm, and the operation was completed. The color tone obtained was the same natural gold color as in Example 2. No dent scratch was observed in the surface scratch test, and scratch resistance was improved.

Example 4 The same sample as in Example 3 was subjected to ion plating by the same method. However, instead of reducing the amount of nitrogen gas on the way, it was once lowered to 60 CC / min, and then increased to 70, 80, 90, 100 CC / min, and the thickness was set to 0.1 μm, and the operation was completed. The color tone was slightly greener than that of the example and deviated from the natural gold color, but no dent scratch was observed in the surface scratch test and the scratch resistance was improved.

A wristwatch case made of stainless steel SUS303 was inserted into a sputtering device to deposit gold-colored titanium titanium. The sputter film forming conditions are as follows. RF power (13.56 [MHz]) Ti 18w / c
m ² sputtering gas Ar 45 cc /
Min, N ₂ 8 to 5 cc / min Pressure 0.05 Torr Substrate temperature 600 ° C. The flow rate of nitrogen gas was changed while keeping the sputtering conditions constant.

The order of film formation is such that metallic titanium is first deposited to a thickness of 0.1 μm, and the nitrogen gas amount is sequentially set to 8, 7, 5
The operation was terminated by setting the total thickness of the three layers to 0.1 μ as cc / min. The color tone obtained was a natural golden color with a slight whitish tint. In the surface scratch test, dent scratches were observed, which was insufficient.

The dent damage was eliminated by forming a hard film-forming layer during film formation. As described above, it is possible to form a film by sputtering similarly to the film formation by ion plating.

[0018]

INDUSTRIAL APPLICABILITY The present invention provides a natural gold color by continuously or stepwise changing the amount of nitrogen gas to be supplied when forming a gold-colored titanium nitride film by ion plating or sputtering on a wristwatch or a decorative article. It is possible to form a titanium nitride film that is close and is not easily scratched.

Claims (3)

[Claims] 1. In a method of forming a gold titanium nitride film on a material by ion plating or sputtering, the amount of nitrogen gas supplied into the vacuum chamber is changed stepwise from the initial setting amount according to the evaporation amount of metallic titanium. A method for producing a watch component and a decorative article coated with titanium nitride, which comprises continuously reducing and forming a film. 2. The timepiece component according to claim 1, wherein a hard titanium nitride film is formed by controlling the amount of nitrogen gas, and then the film is formed by reducing the amount of nitrogen gas continuously or stepwise. And a method for manufacturing an ornament. 3. The method of manufacturing a watch component and a decorative article according to claim 2, wherein the film is formed by continuously or stepwise increasing the amount of nitrogen gas.