JPS61127858A - Golden color external parts - Google Patents

Abstract

PURPOSE:To make inconspicuous the wear of a gold or gold alloy film by the golden color of titanium carbonitride even if said film wears in the stage of producing golden color external parts such as ornaments by forming a titanium carbonitride layer as an underlying layer for the gold or gold alloy film. CONSTITUTION:A wristwatch case made of a stainless steel is cleaned by an org. solvent, acid and alkali and thereafter the golden colored film of the titanium carbonitride which resembles more closely to the golden color than titanium nitride is formed thereon by an ion plating method, sputtering method, etc. Gold or golden colored gold-nickel alloy is coated thereon by a vacuum deposition, ion plating, sputtering, electroplating or chemical plating method. The underlaying titanium carbonitride layer is golden colored and therefore even if the soft gold or gold alloy film is worn, the wear of the film of gold, etc. is inconspicuous. The cost is therefore reduced without deterioration of appearance even if the costly gold or gold alloy layer is made thin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a golden exterior part used for a watch case, a watch band, an eyeglass frame, an accessory, etc.

[Conventional technology]

Conventionally, gold or gold alloy material itself or its plated products have been used as gold exterior parts, but in recent years, a vapor phase plating method called physical vapor deposition has been developed, and very highly durable gold-colored materials such as titanium nitride have been developed. Abrasive superhard metal coatings have been developed and are beginning to be widely used. Furthermore, gold-colored exterior parts have come to be manufactured by using this titanium nitride coating as a base layer and forming a gold or gold alloy coating thereon. for example,
Such a golden exterior part is disclosed in Japanese Patent Publication No. 59-26664.

[Problem that the invention seeks to solve]

However, conventional gold-plated materials and gold-plated products have the disadvantage that they are expensive due to wear resistance, etc., and the titanium nitride coating has a greenish tinge. Furthermore, when a gold or gold alloy coating is formed on the titanium nitride coating described above, if the upper gold or gold alloy layer wears out,
The underlying titanium nitride appears. In this case, titanium nitride has a rather strong green tinge compared to gold or gold alloys, which has the disadvantage of making the difference clearly visible and causing discomfort.

Therefore, in order to solve these conventional drawbacks, the present invention aims to provide a gold-colored exterior component that is low in cost and whose color change due to wear is minimized as much as possible.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a gold-colored carbonitrided base layer formed by a physical vapor deposition method such as ion blasting or sputtering, or a chemical vapor deposition method using a thermal reaction or plasma, on a metal or heat-resistant substrate. Gold color is achieved by forming a titanium film and then forming a gold or gold alloy film as an upper layer on top of the titanium film by vapor phase plating such as vacuum vapor Nl ion blating or sputtering, or wet plating such as electroplating or electroless plating. Exterior parts are obtained.

As mentioned above, the titanium carbonitride film formed on the metal or heat-resistant substrate has a subdued green color compared to the titanium nitride film, and is closer to the golden color tone of gold or gold alloy, so it is partially Even if a portion of the upper gold or gold alloy coating is worn away and the lower titanium carbonitride coating is exposed, the difference in color tone is small, so there is little discomfort.

Figure 1 shows the Hunter color difference, and the origin in the diagram shows the gold plating in a color called Milton Gold, which is often used for wristwatch cases. In this figure, the right direction means strong red, the left direction means strong green, similarly the upward direction means strong yellow, and the downward direction means strong blue. In this figure, curve 1 shows the change in color difference with respect to the gold plating of the titanium-nitrogen binary system, that is, the titanium nitride film system, created by ion blating, and the titanium nitride system has no gold plating throughout. It can be seen that the green color is stronger. Further, curves 2 and 3 show the color difference change of the titanium-nitrogen-carbon ternary yarn, that is, the titanium carbonitride coating, due to ion blasting, and it can be seen that depending on the composition, the color tone is extremely close to that of gold plating. That is, as mentioned above, even if a portion of the upper gold or gold alloy coating is worn out, there is no need for a large change in color tone, and no discomfort is caused.

〔Example〕

The present invention will be explained below based on Examples.

[Example 1] After cleaning a stainless steel watch case with an organic solvent, an acid, and an alkali, it was set in a jig installed in an ion blating device called an active reaction vapor deposition method.
After evacuation to ×10-Torr, nitrogen partial pressure 1.5
X 10″″”Torr, acetylene partial pressure 2X10-
'Titanium is heated and evaporated by an electron beam in an atmosphere of TOrr, and a discharge plasma is formed using the ion blating mechanism provided, forming a gold-colored titanium carbonitride film of about 1 μm on the set watch case. did. Next, use the same device again to 5×10″6 without turning off the vacuum.
After exhausting to Torr, gold containing 5% nickel by weight was heated and evaporated with an electron beam and high-frequency ion blating was performed to form a gold-nickel alloy film of approximately α1μ, which is commonly used in wristwatches called Hamilton Gold. It had a gold-colored coating, which is commonly used in the industry.

This sample was subjected to a cowhide sliding wear test at a load of 500? When the test was repeated 50,000 times, the underlying golden titanium carbonitride layer appeared in some areas, but the difference in color tone was barely noticeable to the naked eye. Further, in this wear test, no wear of the underlying titanium carbonitride coating was observed.

[Example 2] As in Example 1, a stainless steel watch case was cleaned and set in an ion grating device, and a 5X10-
'Evacuate to Torr, nitrogen partial pressure ◇5X10-''
Torr, titanium is heated and evaporated by an electron beam in an atmosphere with acetylene partial pressure of 2 x 10'''rorr, and the gold color is applied to the set watch case while forming discharge plasma using the equipped ion blating mechanism. A titanium carbonitride film having a thickness of about 1 μm was formed.Next Q
Without turning off the vacuum, the vacuum is again evacuated to 5X10-' Torr, nickel is heated and evaporated with an electron beam, and ion grating is performed to reduce the nickel film to about 0.
02 μm was formed. After that, the vacuum was turned off, the sample watch case was taken out into the atmosphere, and pure gold plating was performed by wet electroplating.
When heat treatment was performed for a minute, the intermediate nickel coating was diffused into the upper gold plating layer and alloyed. As a result, the upper gold plating layer became a gold-nickel alloy layer and became a Hamilton gold color.

When this sample was subjected to the same abrasion test as in Example 1, almost the same results were obtained; the intermediate nickel layer was completely diffused and alloyed, and its color did not appear even with abrasion, causing no problems at all. Ta.

[Example 5] As in Example 1, a stainless steel watch case was cleaned and set in an ion grating device, and a 5X10-
' Evacuate to TOrr, nitrogen partial pressure, 5X10-3
Torr, titanium is heated and evaporated by an electron beam in an atmosphere with an acetylene partial pressure of 2 x 10-4 Torr, and a golden color is formed on the watch set while generating discharge plasma using the ion blating mechanism. A titanium carbonitride film with a thickness of about 1 μm was formed. Then,
The apparatus was exposed to the atmosphere, the watch case was taken out, and gold-nickel alloy plating was formed into a shape of approximately 111 m by wet electroplating.

When this sample was subjected to the same wear test as in Example 1, similar results were obtained.

〔Effect of the invention〕

As explained above, this invention forms a gold or gold alloy coating on a titanium carbonitride coating having a golden color.
Even if the upper gold or gold alloy coating wears out, it will hardly be noticeable because the lower titanium carbonitride coating has a very similar color tone. For this reason, the thickness of the gold or gold alloy plating film can be reduced to less than one-hundredth of the thickness of conventional gold plating, which can significantly reduce the number of companies using expensive gold, contributing greatly to cost reduction effects. can do.

In the examples, stainless steel watch cases and watch bands were used as treated objects, but it is clear that the present invention is also effective with other materials and parts. In addition, although it has been described that a golden titanium carbonitride film is formed by ion blasting to an extent of about 1 μm, a similar titanium carbonitride film can be formed by other methods such as sputtering or plasma CVD, but they are effective. There is no difference from the ion blating method, and the thickness is 0.01.
The inventor's experiments have revealed that it can be used as decorative exterior parts if the thickness is in the range of about 10 μm. Furthermore, regarding the gold or gold alloy coating, possible methods for forming it include vacuum evaporation, ion blasting, dry processes such as sputtering IJ7, wet processes such as electroplating, and thermal diffusion methods after forming a multilayer film. Regarding the film thickness, the thinner the film, the greater the cost advantage, but it has been confirmed through experiments that it is practically preferable to have a film thickness of 0.01 μm or more.

[Brief explanation of drawings]

The figure illustrates the Hunter color difference from Hamilton gold color gold plating of a titanium-nitrogen binary system coating and a titanium-nitrogen purple-carbon ternary system coating by ion blasting. 1...Titanium-desirable element binary system 2...Titanium-nitrogen-carbon ternary system (large amount of nitrogen)
5...Titanium-nitrogen-carbon ternary system (nitrogen content rate)
that's all

Claims (1)

[Claims] A gold-colored exterior component characterized in that a gold or gold alloy coating is formed on a gold-colored titanium carbonitride coating formed on a metal or heat-resistant base material.