JPH10158838A - Ornamental coating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a uniform film even when the film is thin and to provide an ornamental coating member capable of preventing elution of metal from the member without considerably damaging hue and excellent in durability and safety. SOLUTION: The surface of the ornamental member consisting of gold or hold alloy is coated with a hard carbon film having 0.20μm thickness. In this case, the peaks of the film are at 1340±40cm<-1> , 1160±40cm<-1> and 1500±60cm<-1> in Raman spectroscopy, and H1 /H2 0.02 and H2 <H3 , for which H1 is the most intensive peak among the peaks at 1160±40cm<-1> , H2 is the most intensive peak among the peaks at 1330±40cm<-1> , and H3 is most intensive peak among the peaks at 1500±60cm<-1> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a watch exterior part,
The present invention relates to improvements in decorative members such as necklaces, earrings, eyeglass frames, bag hardware, fishing gear, and the like.

[0002]

2. Description of the Related Art Conventionally, as a decorative member, a noble metal, particularly a gold decorative member, has been used for a watch exterior part such as a watch case and a band, and a metal fitting such as a necklace, a piercing, an eyeglass frame, and a handbag. As these gold decorative members, generally, those obtained by wet-plating or dry-plating gold or a gold alloy on the surface of a predetermined base are often used. When these gold platings are applied, plating of Ni or the like is applied as a base layer for enhancing the adhesion of the gold plating.

[0003] Such a member whose surface is formed of gold or a gold alloy is excellent in decorative effect, but since the gold itself is a soft metal, when used as a decorative member, the surface has scratches or the like. There is a problem in that it is likely to occur and the decorativeness is gradually impaired.

Therefore, for the purpose of protecting the surface, it has been proposed to form a hard film such as diamond on the surface of gold or a gold alloy in Japanese Patent Application Laid-Open Nos. 62-180071 and 1-244705.
No. has been proposed.

[0005]

However, the hard carbon films described in JP-A-62-180071 and JP-A-1-244705 are made of high-purity diamond formed by a plasma CVD method or the like. In such a high-purity diamond film, there is a problem that the crystal growth of diamond is remarkable, and the film cannot be formed unless the crystal grains are large and the film thickness is increased. In addition, since irregularities due to the diamond's own shape exist on the surface and irregular reflection occurs on the surface, there is a problem that the surface is whitened and the color of the underlying gold or gold alloy is not exposed. In addition, although irregular reflection due to surface irregularities can be eliminated by polishing the film surface, the mirror polishing of the diamond film surface takes a very long time, so that the productivity is inferior. .

Further, in a member in which a Ni plating layer is applied as a base layer such as gold plating, if the base Ni component is eluted as free metal due to sweat or the like, allergy such as skin irritation occurs at a contact portion with the skin. There was fear.

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

Recently, a material which is plated with gold or a gold alloy without applying Ni plating has been developed (Japanese Patent Laid-Open No. Hei 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, it is possible to form a uniform film even when the film thickness is small, and without significantly impairing the color.
An object of the present invention is to provide a decorative covering member that can prevent elution of metal from a member and has excellent durability and safety.

[0010]

According to the present invention, the surface of a member made of gold or a gold alloy has a Raman spectrum of 1340 ± 40 cm ^-1 and 1160 ± 40 cm ^-1.
And a peak at 1500 ± 60 cm ⁻¹ ,
Among the peaks at 0 ± 40 cm ⁻¹ , the strongest peak intensity is H ₁ , and the strongest peak intensity at 1340 ± 40 cm ⁻¹ is H ₂ , 1500
When the strongest peak intensity among the peaks existing at ± 60 cm ⁻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 a satisfactory hard carbon film with a thickness of 0.2 to 2 μm.

In the case where the member made of gold and / or a gold alloy is a substrate whose surface is plated with gold via Ni plating, the above-mentioned high-density carbon film is formed. The elution of Ni can be prevented.

[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 members are most frequently used as decorative members such as watch exterior parts, necklaces, earrings, eyeglass frames, buttons, and brooches. This member may be made entirely of gold or a gold alloy, 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 H ₁ , 1340 ±
When a strong peak intensity of most intense among the peaks and with H ₂ present in 40 cm ^-1, is important that the peak intensity ratio represented by H ₁ / H ₂ to form a 0.02 or more hard carbon film is there.

A generally 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 a D method or a microwave CVD method. Such a diamond film is usually made of high-purity diamond, and has a structure in which carbon atoms are combined by SP ³ hybridization. In particular, those having a peak only at 1340 ± 40 cm ⁻¹ in the Raman spectrum are frequently used. Further, in part, it contains carbon having a graphite structure bonded by hybridizing SP ^{2 and the} like.
A diamond film having a broad peak around 0 to 1600 cm ^-1 is also known. In addition, this diamond film has large irregularities on the surface after film formation due to the self-shape of the crystal due to large diamond crystal grains, crystal grain boundaries are present, and a large amount of voids are present inside the thin film. In order to form a uniform film, it is necessary to form the film with a thickness of at least 10 μm or more.

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

As described above, the hard carbon film itself has a high hardness, is composed of very dense and fine crystals, and has no voids in the film. In addition, 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 golden color of the member is not significantly impaired.
In addition, since the film surface at the time of film formation is smooth, it is not necessary to polish the surface, or even if necessary, a smooth surface can be formed by polishing in a short time.

Further, since the hard carbon film is dense, even when the member has a base layer of Ni plating or the like, when the member comes into contact with sweat or seawater, voids or crystal grain boundaries in the film are formed. Thus, local erosion of the substrate does not occur, and the substrate has excellent corrosion resistance, and can prevent elution of allergen metal such as Ni in the member.

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 a high smoothness on the surface of the member where excellent corrosion resistance is required. Can be formed.

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
When the high peak intensity of most intense among peaks present the highest intensity peak intensity H _1, 1340 ± 40 cm ^-1 of the peaks present and with H ₂ ^-1, expressed in H ₁ / H ₂ Peak intensity ratio is 0.02 or more, desirably,
It is important that it is between 0.2 and 1.0.

If the peak intensity ratio is less than 0.02, the diamond crystal grains grow too large, causing voids in the film or increasing the surface roughness of the film, so that local corrosion is likely to proceed. Become. Also, if the peak intensity ratio is too large, the ratio of diamond crystals decreases,
Since the film strength may be reduced, the above H ₁ / H
_The peak intensity ratio represented by ₂ is desirably 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 It is also important that This 1500 ± 60cm ^-1
Peak indicates an amorphous phase existing between diamond crystals, and is filled with voids in the film, so that the density of the film can be increased, and thereby, 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, a hard carbon film having a small thickness can be formed, and the elution of metal components in the member can be prevented. From the viewpoint, it is desirable that the density of the hard carbon film is 3.1 g / cm ³ or more. When the density is low, it means that the diamond crystals are reduced or that a large amount of voids are contained, and the hardness of the film is reduced, and the elution of Ni may not be prevented in some cases.

The thickness of the hard carbon film in the decorative covering member of the present invention is 0.2 to 2 μm, particularly 0.5 to 2 μm.
m. By having such a thickness, the color of the member has a dark gold color with a slight addition of the black component of the hard carbon film itself, but when the thickness of the hard carbon film exceeds 2 μm, it is almost blackened. As a result, the gold color of the member almost disappears. If the thickness of the hard carbon film is smaller than 0.2 μm, the strength of the film itself is reduced, so that a crack is easily generated when an impact is applied.

The surface roughness of the hard carbon film surface is Ra
At 0.2 μm or less, particularly 0.1 μm or less, and more preferably at 0.1 μm
It is desirable that the thickness be not more than 05 μm. This is because when the surface roughness exceeds 0.2 μm, the surface becomes white due to irregular reflection on the surface, the gloss is lost, and the decorativeness deteriorates.

Further, according to the decorative covering member of the present invention, the base and the hard carbon film may be used in order to enhance the adhesion to the member made of gold or gold alloy, as long as the tint of gold is not impaired. An intermediate layer made of at least a composite of diamond and metal carbide can be interposed between them.

The reason why the adhesion strength between the hard carbon film and the base material is improved by the interposition of the intermediate layer is considered as follows. Atoms are bonded by intervening 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 bonded by electrical connection. An existing covalent bond has a stronger binding force. Diamond has a strong bonding force because it is constituted by a covalent bond of carbon. Therefore, in order to improve the adhesion strength between diamond and a different compound, it is considered that a covalent compound having a similar bonding mode is desirable. Also, it seems that a compound containing carbon which is a component of diamond has better consistency. There are many metal carbides, most of which are mainly ionic bonds. The covalent carbide includes silicon carbide and boron carbide, but silicon carbide is most desirable in the decorative covering member of the present invention.

Further, the diamond and the metal carbide do not exist in a layer-separated state, but have a structure in which the metal carbide surrounds the diamond and has a structure in which the diamond is distributed in an island shape. Adhesion is improved by the so-called anchor effect.

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 a thermal CVD method in which a 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 area where the film can be formed is small, and the area where the film can be formed is generally 2 mm in diameter.
It is about 0 mm, and its application as a processing member is limited. In addition, when the pressure is too high or the plasma density is too low, if the substrate has a complicated structure or has a curved surface structure, uniform plasma along the structure cannot be obtained, and the film thickness distribution becomes uneven. Prone. On the other hand, in the hot filament CVD method, the filament is liable to be cut, and it is necessary to set the filament in accordance with the shape of the substrate in order to suppress the variation in the film thickness. I have. Moreover, the plasma C
In a diamond film formed by the VD method or the thermal CVD method, a diamond film having a large crystal grain size and having irregularities on the surface having many voids 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 a plasma generation region in a plasma CVD method.
By the method D, the hard carbon film of the present invention can be formed. Moreover, according to the ECR plasma CVD method, a high-density plasma can be obtained under a low pressure (1 torr or less). Therefore, the plasma can be uniformly generated in a wide area, and compared with a normal plasma CVD method. Thus, a film can be formed uniformly in an area of about 10 times.

In this method, a reaction gas is introduced into a reaction furnace in which a predetermined base is placed, and at the same time, 2.45 G is introduced.
Hz microwaves are introduced. At the same time, a magnetic field of a level of 875 Gauss or more is applied to this region. This allows the electrons to have a cyclotron frequency f = eB / 2πm
(Where, m: electron mass, e: electron charge, B: magnetic flux density), cyclotron motion is caused. When this frequency coincides with the microwave frequency (2.45 GHz), it resonates and electrons are remarkably absorbed by the energy of the microwave, accelerated, collide with neutral molecules and cause ionization to generate high-density plasma. Become like At this time, the temperature of the substrate was 150 to 1000 ° C., and the furnace pressure was 1 × 10 ^{−2 to} 1 t.
set to orr.

According to this method, the substrate temperature during film formation,
By changing the furnace pressure and the reaction gas concentration, the components and the like of the formed hard carbon film change. In particular,
As the pressure in the furnace increases, the area of the plasma decreases, and the growth rate of the film decreases, but the crystallinity tends to improve. Also, when the concentration of the reaction gas increases, the size of the particles constituting the film tends to decrease, and the crystallinity tends to deteriorate. By appropriately controlling these conditions as specifically described in Examples described later, it is possible to control H ₁ , H ₂ , and H ₃ in the aforementioned Raman spectrum.

In the above-mentioned film forming method, when producing the decorative covering member of the present invention, hydrogen and a carbon-containing gas are used as raw material gases in forming the hard carbon film. Examples of the carbon-containing gas used include, for example, alkanes such as methane, ethane, and propane; alkenes such as ethylene and propylene; alkynes such as acetylene; aromatic hydrocarbons such as benzene; cycloparaffins such as cyclopropane; And cycloolefins such as cyclopentene. Oxygen-containing carbon compounds such as carbon monoxide, carbon dioxide, 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 can be used alone or in combination of two or more.

In order to form an intermediate layer composed of a mixture of diamond and silicon carbide as described above, after performing a diamond nucleation treatment as desired, hydrogen, a carbon-containing gas and a silicon-containing gas are used as reaction gases. Is introduced. 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 and mono (di, tri, tetra) methylsilane, and trimethyl And silanol compounds such as silanol. These can 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 thickness of 2 μm was formed on the surface of a stainless steel plate as a substrate.
And a 1 μm-thick gold-plated member was placed thereon.

There, H ₂ 294 sccm, CH ₄ 6s
ccm gas, gas concentration 2%, base material temperature 650
° C., and 1 hour at inner pressure 0.1 torr, after generating the diamond nuclei, H ₂ gas as the source gas, C
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 A magnetic field with a maximum intensity of 2K gauss is applied by the electron cyclotron resonance plasma CVD method under the conditions described above, and a film is formed for 3 hours under the condition of a microwave output of 3.0KW to form an intermediate layer containing diamond and silicon carbide on the inner surface of the container. did. The thickness of the intermediate layer was adjusted to about ３ of the total thickness of the hard carbon film. In Table 1, for sample No. 5, an intermediate layer made of silicon carbide was prepared in the same manner as described above except that the intermediate layer was formed at a gas ratio of H ₂ 300 sccm Si (CH ₃ ) ₄ 0.3 sccm. It was formed and evaluated similarly.

Next, using an H ₂ gas, a CH ₄ gas, and a CO ₂ gas having a purity of 99.9% or more on the intermediate layer, Table 1,
Film formation was performed at a gas ratio, a gas concentration, a film formation temperature, and a furnace pressure shown in FIG. 2 to form a hard carbon film having a total thickness of 0.1 to 5 μm including an 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 peak intensity having the highest intensity among the peaks in the region of 1500 ± 60 cm ⁻¹ was designated as H _3, and the magnitude relation between 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. Note that an Ar laser (oscillation line 488.0 nm) was used as a laser as an oscillation source in Raman spectroscopy. Further, the film alone was taken out, and the density of the film was measured by a floating / sedimentation method using a specific gravity solution of thallium formate aqueous solution. Further, the color of the obtained member was observed, and the results are shown in Tables 1 and 2.

Next, the sample was immersed in an aqueous solution and left for 48 weeks. The film surface after standing was observed with a binocular microscope, and the corrosion state is shown in Tables 1 and 2. The amount of Ni metal eluted into 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 state is shown in Tables 1 and 2. Also,
The amount of Ni eluted into the solution was measured by the ICP method, and the results are shown in Tables 1 and 2. Further, a sand blast treatment was performed on the film surface, and a scratch resistance test was performed.

(Comparative Example 1) A corrosion test similar to that of Examples 1 and 2 was conducted using a container which had been subjected to gold plating, 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 as in the Example, with a gas concentration of 2%. Material temperature 650 ° C, furnace pressure 3
After forming the film under the conditions of 0 torr for 4 hours, the film was further formed under the conditions shown in Sample No. 9 in Table 1 to form a 1 μm hard carbon film. This was subjected to color observation and a corrosion test 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 shown in Tables 1 and 2, the comparative sample No. having a hard carbon film having H ₁ / H ₂ 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 irregular reflection, and the gold color had almost disappeared. In addition, a large number of spots of 10 to 1000 μm, which may have been caused by corrosion, were observed on the surface of the film after immersion in aqua regia, corrosion was locally advanced, and elution of Ni was observed. Further, in the sample without the hard carbon film, the plating completely disappeared in 20 minutes against aqua regia. In addition, samples No. _2, 15, 16 with H ₂ > H ₃
In each case, corrosion was observed, and elution of Ni was observed.

On the other hand, the sample of the present invention in which a hard carbon film having H ₁ / H ₂ of 0.02 or more and H ₂ <H _{3 and} a thickness of 0.2 to ₂ μm was formed, had a surface roughness of 0.1 μm. A film having a smooth surface of 1 μm or less and a density of 3.1 g / cm ³ or more;
The color was dark gold to dark gold, and no gold plating corrosion was observed in any of the aqueous solutions. Also, N
The elution of i was below the detection limit.

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

With respect to the scratch resistance, the sample coated with the hard carbon film scarcely had any scratches, but the sample No. 17 having a thin film thickness of 0.1 μm was partially peeled off from the film. Admitted. Further, in Sample No. 21 in which the hard carbon film was not covered, a large number of scratches were observed.

[0048]

As described in detail above, the decorative covering member of the present invention is covered with the dense and smooth hard carbon film made of fine crystals, which greatly impairs the color of the member. In addition, it is possible to prevent scratches and the like, and to prevent the elution of Ni even when Ni plating or the like is applied to the member. Thereby, the durability and safety as a decorative member can be improved.

[Brief description of the drawings]

FIG. 1 shows a hard carbon film (Sample No. in Table 1) of the present invention.
It is a Raman spectrum diagram of 4).

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

Claims (2)

[Claims] A surface of a decorative member made of gold or a gold alloy has a surface of 1340 ± 40 cm in Raman spectrum.
^-1 , 1160 ± 40 cm ^-1 and 1500 ± 60 cm ^-1
And the highest peak intensity among peaks existing at 1160 ± 40 cm ⁻¹ is H ₁ , 1340
When the strongest peak intensity among the peaks existing at ± 40 cm ⁻¹ is H ₂ , and the strongest peak intensity among the peaks existing at 1500 ± 60 cm ⁻¹ is H ₃ , H
A hard carbon film having a peak intensity ratio represented by ₁ / H ₂ of 0.02 or more and satisfying H ₂ <H ₃ is 0.2 to 2
A decorative covering member coated with a film thickness of μm. 2. The decorative member comprising gold or a gold alloy,
2. The decorative covering member according to claim 1, wherein the surface of the base is plated with gold via Ni plating.