JP3515866B2 - Decorative coverings - Google Patents

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,
The present invention relates to improvement of decorative members such as necklaces, piercings, eyeglass frames, metal fittings for bags, and fishing tackles.

[0002]

2. Description of the Related Art Conventionally, as a decorative member, a precious metal, especially a gold-colored decorative member has been used for a watch case, a watch exterior part such as a band, a necklace, a pierce, an eyeglass frame, a metal fitting for a handbag and the like. As these gold-colored decorative members, those in which gold or a gold alloy is wet-plated or dry-plated on the surface of a predetermined base are generally used. Further, in the case of applying these gold platings, Ni or the like is plated as a base layer for strengthening the adhesion of the gold plating.

A member whose surface is formed of gold or a gold alloy has an excellent decorative effect, but since gold itself is a soft metal, when used as a decorative member, the surface is not damaged. However, there is a problem that the decorative property is gradually deteriorated.

Therefore, for the purpose of surface protection, it is necessary to form a hard film such as diamond on the surface of gold or a gold alloy in JP-A-62-180071 and JP-A-1-244705.
It has been proposed in the issue.

[0005]

However, the hard carbon film described in JP-A-62-180071 and JP-A-1-244705 is composed of high-purity diamond formed by plasma CVD method or the like. However, such a high-purity diamond film has a problem that the crystal growth of diamond is remarkable, so that the film cannot be formed unless the film size is large and the crystal grains are large. In addition, there is a problem that the surface is whitened and the tint of the gold or gold alloy of the base is not exposed because the surface has irregularities due to the diamond automorphism and irregular reflection occurs on the surface. Further, although irregular reflection due to unevenness of the surface can be eliminated by polishing the film surface, mirror-polishing the film surface made of diamond requires a very long time and thus is inferior in productivity. .

Further, in a member having a Ni-plated layer as an underlayer such as gold plating, when the Ni component of the underlayer is eluted as free metal by sweat or the like, an allergy such as skin irritation occurs at the contact portion with the skin. I was afraid.

However, even if a conventional diamond film is formed as a protective film, as described above, since the crystal grain size is large, the film contains voids and the like, and elutes on the film surface through these voids. However, the elution of Ni could not be prevented.

Recently, a material plated with gold or a gold alloy without being plated with Ni has been developed (JP-A-8-120481). However, when these materials are used, there is a problem that the color tone of gold changes with time.

Therefore, according to the present invention, even if the film thickness is thin, it is possible to form a uniform film, and the tint is not greatly impaired.
An object of the present invention is to provide a decorative covering member which is excellent in durability and safety capable of preventing metal from being eluted from the member.

[0010]

According to the present invention, the substrate surface is
1340 ± 4 in Raman spectrum on the surface of the decorative member whose surface is plated with gold through Ni plating.
0 cm ^-1 , 1160 ± 40 cm ^-1 and 1500 ±
There is a peak at 60 cm ^-1 and 1160 ± 40 cm
⁻¹ , the strongest peak intensity among the peaks present at ⁻¹ is H ₁ , and the strongest peak intensity among the peaks present at 1340 ± 40 cm ⁻¹ is H ₂ , 1500 ± 60 c.
When the strongest peak intensity among the peaks existing in m ⁻¹ is H ₃ , the peak intensity ratio represented by H ₁ / H ₂ is 0.02 or more, and H ₂ <H ₃ is satisfied. The above object is achieved by coating the hard carbon film to be coated with a film thickness of 0.2 to 2 μm.

The surface roughness Ra is 0.2 μm or less.
It is desirable to do.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the decorative covering member of the present invention, the member used is a member whose surface is formed of gold and / or a gold alloy. Such gold-colored members are most frequently used as decorative members such as exterior parts for watches, necklaces, piercings, eyeglass frames, buttons and broaches. This member may be made of gold or gold alloy as a whole, or may be made of gold plating.

According to the present invention, the surface of the member made of such a gold or gold alloy, Raman spectrum at 1340 ± 40 cm ^-1, peak exists in 1160 ± 40 cm ^-1, and 1160 ± 40 cm ^-1 Of the peaks present in H ₁ , 1340 ±
It is important to form a hard carbon film having a peak intensity ratio represented by H ₁ / H ₂ of 0.02 or more, where H ₂ is the strongest peak intensity among the peaks existing at 40 cm ^−1. is there.

A commonly known diamond film has a thermal CV.
It is known that the diamond film can be formed by a thin film forming method such as D method or microwave CVD method, but such a diamond film is usually made of high-purity diamond and has a structure in which carbon atoms are bonded by SP ³ hybrid. In particular, those having a peak only at 1340 ± 40 cm ⁻¹ in Raman spectrum are often used. In addition, some of them include carbon having a graphite structure which is bonded by SP ² hybridization, and the like.
A diamond film having a broad peak around 0 to 1600 cm ^-1 is also known. In addition, since the diamond film has large diamond crystal grains, this diamond film has large surface irregularities due to the self-form of the crystal, crystal grain boundaries exist, and a large number of voids exist inside the thin film. In order to obtain a uniform film, it is necessary to form the film with a film thickness of at least 10 μm or more.

On the other hand, the hard carbon film of the present invention, which is mainly composed of diamond, has a Raman spectrum of at least 1340 ± 40 c.
It has a peak at m ⁻¹ , 1160 ± 40 cm ⁻¹ . Among the above peaks, the peak at 1340 ± 40 cm ⁻¹ indicates the peak of diamond crystal and is 1160 ± 40 c.
The m- ¹ peak is considered to indicate the presence of a diamond precursor or polyene structure, and is considered to mean that it is formed by extremely fine crystals. Therefore, the hard carbon film in the present invention is a highly dense film in which diamond crystals are extremely fine and have an average grain size of 1 μm or less, and there are almost no voids in the film.

As described above, since the hard carbon film itself has high hardness, is extremely dense and is composed of fine crystals, and has no voids in the film, it is not scratched when used as a decorative member, Moreover, it is possible to form a uniform film with a thin film thickness, and since the surface is smooth, there is no irregular reflection on the surface and the tint of the gold color of the member is not greatly impaired.
Moreover, since the film surface during film formation is smooth, there is no need to polish the surface, or if necessary, a smooth surface can be formed by a short polishing time.

Further, since this hard carbon film is dense, even if the member has an underlayer such as Ni plating, when it comes into contact with sweat or seawater, voids and crystal grain boundaries in the film are formed. Through this, local erosion of the substrate does not occur, it has excellent corrosion resistance, and it is possible to prevent the allergen source metal such as Ni in the member from eluting.

Further, the hard carbon film can form a smooth and dense film surface conforming to the surface shape of the member on the surface of the member of any shape, and has high smoothness on the surface of the member which is required to have excellent corrosion resistance. Can be formed with.

The peak intensity in the Raman spectrum of the hard carbon film of the present invention will be specifically described. As shown in FIG. 1, the hard carbon film of the present invention has peaks at least at 1340 ± 40 cm ⁻¹ and 1160 ± 40 cm ⁻¹ . 1160 peak intensity of ± 40 cm ^-1 is to draw oblique lines between positions 1100 cm ^-1 and 1700 cm ^-1, this as a baseline, 1160 ± 40 cm
^Where H ₁ is the highest peak intensity among the peaks present at ⁻¹ and H ₂ is the highest peak intensity among the peaks present at 1340 ± 40 cm ⁻¹ , it is represented by H ₁ / H _2. Peak intensity ratio is 0.02 or more, preferably,
It is important to be 0.2 to 1.0.

If the peak intensity ratio is less than 0.02, the diamond crystal grains grow too much, and voids are generated in the film or the surface roughness of the film becomes large, so that local corrosion is likely to proceed. Become. Further, if the peak intensity ratio is too large, the diamond crystal ratio decreases,
Since the film strength may decrease, the above H ₁ / H
_The peak intensity ratio represented by ₂ is preferably 1.0 or less.

In the Raman spectrum,
As shown in FIG. 1, it has a peak at 1500 ± 60cm ^-1, when a strong peak intensity of most intense among within the region of the peaks was set to H _3, satisfy the relationship of H ₁ <H ₂ <H ₃ What you do is also important. This 1500 ± 60 cm ^-1
The peak of indicates the amorphous phase existing between the diamond crystals, and since it is filled in the voids in the film, the density of the film can be increased, whereby the elution of Ni can be more effectively performed. Can be prevented.

According to the decorative covering member of the present invention,
Since the hard carbon film is dense, it is possible to form a thin hard carbon film and prevent elution of metal components in the member. From the viewpoint, the density of the hard carbon film is preferably 3.1 g / cm ³ or more. When the density is low, it means that the diamond crystals are reduced or a large amount of voids are contained, which may cause a decrease in hardness of the film or may prevent the elution of Ni.

The hard carbon film in the decorative covering member of the present invention has a thickness of 0.2 to 2 μm, particularly 0.5 to 2 μm.
It must be m. With such a thickness, the tint of the member is such that the black component of the hard carbon film itself is slightly added and it has a dark gold color, but when the thickness of the hard carbon film exceeds 2 μm, it is almost blackened. As a result, the golden color of the member has almost disappeared. Further, if the thickness of this hard carbon film is less than 0.2 μm, the strength of the film itself is reduced, so that cracks easily occur when an impact is applied.

The surface roughness of the hard carbon film surface is Ra
At 0.2 μm or less, particularly at 0.1 μm or less, and even 0.
It is desirable that the thickness is 05 μm or less. This is because if the surface roughness exceeds 0.2 μm, the surface is irregularly reflected, whitening occurs, the gloss is lost, and the decorative property deteriorates.

Further, according to the decorative covering member of the present invention, in order to improve the adhesiveness with a member made of gold or a gold alloy, provided that the base and the hard carbon film are provided within a range not impairing the tint of gold color. An intermediate layer made of at least a composite of diamond and metal carbide can be interposed between the two.

The reason why the adhesion strength between the hard carbon film and the base material is improved by the interposition of such an intermediate layer is considered as follows. Atoms are bonded by interposing electrons, but in general, electrons are shared by both atoms rather than ionic bonds in which electrons between atoms are present on one side and are bonded by an electrical connection. A covalent bond that has a stronger bond strength. Since diamond is composed of carbon covalent bonds, it has a strong bonding force. Therefore, in order to improve the adhesion strength between diamond and a heterogeneous compound, it is considered that a covalent compound having a similar bonding mode is desirable. In addition, the compound containing carbon, which is a component of diamond, seems to be more consistent. Many metal carbides exist, but most of them are mainly ionic bonds. The covalently bonded carbide includes silicon carbide and boron carbide, but silicon carbide is most preferable in the decorative covering member of the present invention.

Further, the diamond and the metal carbide do not exist in separate layers, but have a structure in which the metal carbide surrounds the diamond, and the diamond has a structure in which it is distributed in an island shape. The so-called anchor effect improves the adhesion.

As a method for forming a hard carbon film, conventionally, as a means for forming a diamond film, a so-called plasma CVD method or thermal method is used in which plasma is generated by microwave or high frequency to form a carbon film on a predetermined substrate surface. The filament method is the mainstream. However, in the plasma CVD method, since the plasma generation region is small, the film formation area is small, and the film formation area is generally 2 mm in diameter.
Since it is about 0 mm, its application as a processing member is limited. If the substrate has a complicated structure or a curved structure because the pressure is too high or the plasma density is too low, uniform plasma cannot be obtained along the structure and the film thickness distribution becomes uneven. Prone. On the other hand, in the hot filament CVD method, the filament is easily broken, and it is necessary to install the filament in conformity with the shape of the substrate in order to suppress the variation in the film thickness, so that the apparatus lacks versatility. There is. Moreover, the plasma C
The diamond film formed by the VD method or the thermal CVD method has a large crystal grain size, and a diamond film having many voids and unevenness on the surface is easily generated.

On the other hand, according to the present invention, a so-called electron cyclotron resonance (ECR) plasma CV in which a magnetic field is applied to the plasma generation region in the plasma CVD method.
The hard carbon film in the present invention can be formed by the D method. Moreover, according to this ECR plasma CVD method, since high-density plasma can be obtained under a low pressure (1 torr or less), it is possible to uniformly generate plasma in a wide area, and compared with the ordinary plasma CVD method. Thus, a film can be uniformly formed in an area of about 10 times.

In this method, a reaction gas is introduced into a reaction furnace having a predetermined substrate installed therein, and 2.45 G
Introduce microwave of Hz. At the same time, a magnetic field having a level of 875 Gauss or more is applied to this region. This causes the electron to have a cyclotron frequency f = eB / 2πm.
(However, m: electron mass, e: electron charge, B: magnetic flux density) causes cyclotron motion. When this frequency coincides with the microwave frequency (2.45 GHz), it resonates, and the electrons remarkably absorb the microwave energy and are accelerated, colliding with neutral molecules and causing ionization to generate high-density plasma. Like At this time, the temperature of the substrate is 150 to 1000 ° C., the furnace pressure is 1 × 10 ^{-2 to} 1 t.
Set to orr.

According to such a method, the substrate temperature during film formation,
By changing the furnace pressure and the reaction gas concentration, the components of the hard carbon film to be formed change. In particular,
When the furnace pressure increases, the plasma region decreases and the film growth rate decreases, but the crystallinity tends to improve. Further, when the reaction gas concentration becomes high, the size of the particles forming the film becomes small, and the crystallinity tends to deteriorate. H ₁ , H ₂ , and H ₃ in the Raman spectroscopy spectrum described above can be controlled by appropriately controlling these conditions as specifically described in Examples described later.

In the above film forming method, when the decorative covering member of the present invention is produced, hydrogen and carbon-containing gas are used as raw material gases when forming the hard carbon film. Examples of the carbon-containing gas used include alkanes such as methane, ethane and propane, alkenes such as ethylene and propylene, alkynes such as acetylene, aromatic hydrocarbons such as benzene and cycloparaffins such as cyclopropane. Examples thereof include cycloolefins such as cyclopentene. In addition, carbon monoxide, carbon dioxide, oxygen-containing carbon compounds such as methyl alcohol, ethyl alcohol and acetone, and nitrogen-containing carbon compounds such as mono (di, tri) methylamine and mono (di, tri) ethylamine are also used as carbon source gases. Can be used. These may be used alone or in combination of two or more.

In order to form the intermediate layer made of a mixture of diamond and silicon carbide as described above, a diamond nucleation treatment is carried out if desired, and then hydrogen, a carbon-containing gas and a silicon-containing gas are used as reaction gases. To introduce. As the silicon-containing gas, silicon tetrafluoride,
In addition to halides such as silicon tetrachloride and silicon tetrabromide, oxides such as silicon dioxide, silane compounds such as mono (di, tri, tetra, penta) silane, mono (di, tri, tetra) methylsilane, trimethyl Examples thereof include silanol compounds such as silanol. These may be used alone or in combination of two or more.

[0034]

【Example】

(Example) In a furnace of an electron cyclotron resonance plasma CVD apparatus, a surface of a stainless steel plate serving as a substrate has a thickness of 2 μm.
The Ni alloy plating, and a member having a thickness of 1 μm and further plated with gold were placed thereon.

There, H ₂ 294 sccm, CH ₄ 6s
ccm gas, gas concentration 2%, base material temperature 650
After processing for 1 hour at a temperature of 0.1 ° C. and a furnace pressure of 0.1 torr to generate diamond nuclei, H ₂ gas and C are used as raw material gases.
Using H ₄ gas and Si (CH ₃ ) ₄ gas, H ₂ 294 sccm CH ₄ 6 sccm Si (CH ₃ ) ₄ 0.3 sccm, gas concentration 2%, base material temperature 650 ° C., furnace pressure 0.05 torr By applying a magnetic field with a maximum intensity of 2K gauss by electron cyclotron resonance plasma CVD method under the conditions described above, and depositing a film for 3 hours under the condition of microwave output of 3.0KW, an intermediate layer in which diamond and silicon carbide are mixed is formed on the inner surface of the container. did. The thickness of the intermediate layer was adjusted to about 1/3 of the total thickness of the hard carbon film. Further, in Table 1, for sample No. 5, an intermediate layer made of silicon carbide was formed in exactly the same manner as described above except that the formation of the intermediate layer was carried out at a gas ratio of H ₂ 300 sccm Si (CH ₃ ) ₄ 0.3 sccm. It was formed and evaluated in the same manner.

Next, H ₂ gas, CH ₄ gas, and CO ₂ gas having a purity of 99.9% or more were used on the intermediate layer, as shown in Table 1.
Film formation was carried out at the gas ratio, gas concentration, film formation temperature, and furnace pressure shown in 2 to form a hard carbon film having an overall thickness of 0.1 to 5 μm including the intermediate layer.

[0037] For the formed hard carbon film, subjected to Raman spectrum analysis of the film surface, draw a line between positions 1100 cm ^-1 and 1700 cm ^-1 from the Raman spectrum chart, which was the baseline, 1160 ± 40
The peak intensity of the maximum peak existing at cm ⁻¹ is H ₁ , 13
The peak intensity of the maximum peak present in 40 ± 40 cm ^-1 as H _2, was calculated intensity ratio expressed by H ₁ / H _2.
In addition, the strongest peak intensity among the peaks in the region of 1500 ± 60 cm ⁻¹ was defined as H _3, and the magnitude relationship among H ₁ , H ₂ and H ₃ was shown. In Table 1, sample No. 4 and sample N
Charts for o.9 are shown in FIGS. An Ar laser (oscillation line 488.0 nm) was used as a laser in the Raman spectroscopic analysis. In addition, the film alone was taken out, and the density of the film was measured by a float-sink method using a specific gravity liquid of a thallium formate aqueous solution. Furthermore, the tint of the obtained member was observed, and the results are shown in Tables 1 and 2.

Next, the sample was immersed in an aqua regia solution and left for 48 weeks. The film surface after standing was observed with a binocular microscope and the corrosion states are shown in Tables 1 and 2. The amount of Ni metal eluted in the solution was measured by the ICP method, and the results are shown in Tables 1 and 2.

The surface of the obtained sample after standing was observed with a binocular microscope and the corrosion states are shown in Tables 1 and 2. Also,
The amount of Ni eluted in the solution was measured by the ICP method, and the results are shown in Tables 1 and 2. Further, the surface of the film was subjected to a sandblasting treatment and a scratch resistance test was conducted.

(Comparative Example 1) The same corrosion test as in Example 1 and Example 2 was carried out using a container plated with gold, and the results are shown in Sample No. 17 in Table 2.

(Comparative Example 2) The same gold-plated stainless steel plate as that used in Example 1 was used as the base material, and the intermediate layer was formed by microwave CVD at the same gas ratio and gas concentration of 2% as in the example. Material temperature 650 ℃, furnace pressure 3
After forming the film under the condition of 0 torr for 4 hours, the film was further formed under the condition shown in Sample No. 9 of Table 1 to form a hard carbon film of 1 μm. For this, color tint observation and corrosion test were performed in the same manner as in Example 1, and the results are shown in Table 1, Sample No. 9.

[0042]

[Table 1]

[0043]

[Table 2]

According to the results of Tables 1 and 2, a comparative sample No. 1 having a hard carbon film in which H ₁ / H ₂ was lower than 0.02 was formed.
In Nos. 1, 2, 9, and 10, the surface roughness of the film exceeded 0.2 μm, the surface was whitened due to diffused reflection, and the gold color had almost disappeared. Moreover, a large number of spots of 10 to 1000 μm, which may be due to corrosion, were observed on the surface of the film after soaking in aqua regia, and corrosion was locally progressing, and elution of Ni was observed. Further, in the sample without the hard carbon film, the plating was completely lost in 20 minutes with respect to aqua regia. In addition, samples No. _2, 15, 16 of H ₂ > H ₃
In each case, corrosion was observed and Ni was eluted.

On the other hand, the sample of the present invention in which the hard carbon film having H ₁ / H ₂ of 0.02 or more and H ₂ <H _{3 and} the thickness of 0.2 to ₂ μm was formed had a surface roughness of 0. A film having a smooth surface of 1 μm or less and a density of 3.1 g / cm ³ or more,
The tint was dark gold to dark dark gold, and no gold plating corrosion was observed in any of the aqua regia solutions. Also, N
The elution of i was below the detection limit.

However, in the sample No. 17 in which the thickness of the hard carbon film is thinner than 0.2 μm, the film is partly peeled off and the film thickness is 2 μm.
In the sample No. 20 exceeding m, almost gold color was lost,
It turned black.

Regarding the scratch resistance, the sample coated with the hard carbon film showed almost no scratches, but the sample No. 17 having a thin film thickness of 0.1 μm had a part of the film peeled off. Admitted. Further, in Sample No. 21 which was not covered with the hard carbon film, many scratches were recognized.

[0048]

As described above in detail, since the decorative covering member of the present invention is covered with a dense hard carbon film made of fine crystals and having a smooth surface, the tint of the member is greatly impaired. Without being easily scratched, Ni can be prevented from being eluted even when the member is plated with Ni or the like. As a result, the durability and safety of the decorative member can be improved.

[Brief description of drawings]

1 is a hard carbon film of the present invention (in Table 1, sample No.
It is a Raman spectroscopy spectrum figure of 4).

FIG. 2 shows a hard carbon film as a comparative example (in Table 1, sample No.
It is a Raman spectroscopy spectrum figure of 9).

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) C23C 14/00-14/58 C23C 16/00-16/56 C01B 31/00-31/36 JCTP file (JOIS)

Claims (2)

(57) [Claims] 1. A substrate surface is gold-plated through Ni plating.
On the surface of the decorative member subjected to the treatment, the Raman spectrum was 1340 ± 40 cm ⁻¹ , 1160 ± 40 cm.
⁻¹ and 1500 ± 60 cm ⁻¹ have peaks,
The strongest peak intensity among the peaks present at 1160 ± 40 cm ⁻¹ is H ₁ , and the strongest peak intensity among the peaks present at 1340 ± 40 cm ⁻¹ is H ₂ , 1500 ± 60 cm ⁻¹ . When the strongest peak intensity among the peaks is H ₃ , H ₁ / H ₂
The peak intensity ratio is 0.02 or more, and H
A decorative coating member, characterized in that a hard carbon film satisfying ₂ <H ₃ is coated with a film thickness of 0.2 to 2 μm. 2. The surface roughness Ra of the surface of the hard carbon film is
The covering member for decoration according to claim 1, which has a thickness of 0.2 μm or less .