JP7781604B2 - Decorative materials - Google Patents

Description

The present invention relates to decorative members. More specifically, it relates to copper alloy decorative members intended for use in environments requiring corrosion resistance due to moisture.

Patent Document 1 discloses a technology for improving the stain resistance of wet area components used in indoor wet environments. Specifically, a DLC (diamond-like carbon) coating is formed on the surface of the substrate of the wet area component. The DLC coating contains more than a specified amount of hydrogen atoms and has a density lower than a specified value, thereby enhancing both its stain resistance and stain resistance durability.

Patent No. 6641596

With the technology described in Patent Document 1, the density of the DLC coating is low, so there is a concern that moisture on the coating surface may penetrate into the interior, causing potential corrosion between the coating and the substrate and resulting in coating peeling. One possible solution to this problem would be to thicken the DLC coating, but because DLC coatings generate high residual stress during deposition, thickening the coating is undesirable as it actually makes the coating more susceptible to peeling. Therefore, the present invention provides a copper alloy decorative component that can appropriately improve corrosion resistance due to moisture.

To solve the above problems, the decorative member of the present invention takes the following measures. Specifically, the decorative member of the present invention is a copper alloy decorative member intended for use in environments requiring corrosion resistance due to moisture, and includes at least a copper alloy base material body, a metal layer, and a DLC coating layer. The metal layer is disposed between the DLC coating layer and the base material body. The DLC coating layer is made of a ta-C coating whose surface layer has a refractive index of 1.5 to 3.0 at a wavelength of 550 nm. The thickness of the DLC coating layer is 0.5 to 5.0 μm.

Here, DLC coatings are generally known as amorphous carbon coatings containing the SP-3 structure. DLC is classified into four types based on its sp2 bond-sp3 bond ratio and hydrogen content: ta-C (tetrahedral amorphous carbon), a-C (amorphous carbon), ta-C:H (hydrogenated tetrahedral amorphous carbon), and a-C:H (hydrogenated amorphous carbon).

Of these, ta-C has the highest proportion of SP-3 structure among DLCs and is known to have the highest density and hardness. ta-C also has excellent wear resistance, insulation, heat resistance, and chemical non-reactivity. It can be formed using the vacuum arc deposition method, which is classified as a PVD (physical vapor deposition) method. Vacuum arc deposition is a method of depositing a thin film onto a workpiece using vacuum arc plasma (vacuum arc discharge plasma) containing high-energy ions generated by arc discharge in a vacuum (vacuum arc discharge).

With the above configuration, by providing a DLC coating layer made of a high-density ta-C coating with the above refractive index on the base material body, it is possible to appropriately prevent moisture penetration from the surface of the component. The DLC coating layer is provided on the base material body with an intermediate metal layer in between, allowing it to be formed on the base material body with good adhesion. These configurations can appropriately improve the corrosion resistance of the decorative component due to moisture.

The decorative member of the present invention may also be further configured as follows: The DLC coating layer contains 50 to 90% of the SP-3 structure, and the coating has a Vickers hardness of 1,500 to 5,000 Hv. This configuration allows the DLC coating layer to function as a corrosion-resistant coating made of a ta-C coating with a more appropriate hardness.

The decorative member of the present invention may also be configured as follows: The surface roughness Ra of the DLC coating layer is 0.1 μm or less, and the surface defects of the DLC coating layer are 20% or less. This configuration allows the DLC coating layer to function as a corrosion-resistant coating made of a ta-C coating with a smoother surface and lower friction.

Here, "surface defects" in the DLC coating layer include, for example, situations in which droplets (macroparticles) adhere to the surface of the DLC coating layer, causing a deterioration in film quality. Droplets are electrically neutral evaporated particles that can be emitted from solid graphite, the evaporation source of the cathode target, when forming a ta-C coating using vacuum arc evaporation. When droplets adhere to the coating, they form irregularities on the coating's surface. Furthermore, because droplets have an SP-2 structure, which is the compositional structure of solid graphite, or a compositional structure similar to it, their adhesion to the coating can cause a deterioration in the mechanical properties of that area.

Therefore, if droplets adhere to the coating surface, there is a risk that the geometric uniformity (flatness) and chemical uniformity of the coating will not be guaranteed. Furthermore, the areas of the coating where droplets adhere may become the starting point for coating peeling or the starting point for deterioration of the protective coating. One known method for suppressing droplet adhesion is to filter droplets from the plasma during plasma transport (known as the FCVA method (filtered cathodic vacuum arc)).

The decorative member of the present invention may also be configured as follows: The DLC coating layer contains 5% by mass or less of hydrogen. This configuration allows the ta-C coating layer to be formed with better adhesion to the intermediate metal layer, due to the low hydrogen content. Furthermore, the DLC coating layer can function as a corrosion-resistant coating made of ta-C, which has superior mechanical properties.

The decorative member of the present invention may also be configured as follows: The base material body is a copper alloy containing 50% or more copper, with the remainder consisting of lead, zinc, tin, iron, nickel, and antimony. With this configuration, the moisture corrosion resistance of the base material body, which is made of a copper alloy of the above composition and is used for faucet piping, etc., can be appropriately improved by the DLC coating layer.

The decorative member of the present invention may also be configured as follows: The metal layer is a layer containing at least one metal selected from the group consisting of nickel, titanium, chromium, and tungsten. This configuration allows the DLC coating layer to be formed with better adhesion to the base material body via the metal layer selected from the above group.

The decorative member of the present invention may also be configured as follows: The metal layer includes a first metal layer and a second metal layer, with at least a portion of the second metal layer disposed on the first metal layer. According to this configuration, by forming the metal layer into a multi-layer structure, for example, the second metal layer, which is the layer closer to the DLC coating layer, is formed from a metal that has a higher adhesiveness to the DLC coating layer, and the first metal layer, which is the layer closer to the base material body, is formed from a metal that has a higher adhesiveness to the base material body, making it possible to form the DLC coating layer with better adhesion to the base material body.

The decorative member of the present invention may also be configured as follows: The refractive index of the surface layer of the DLC coating layer is 2.0 to 3.0 at a wavelength of 550 nm. This configuration allows a DLC coating layer made of a higher-density ta-C coating with the above refractive index to be formed on the base material body, thereby more appropriately improving the corrosion resistance of the decorative member due to moisture.

The decorative member of the present invention may also be configured as follows: The base material body has an uneven shape. In the DLC coating layer, a portion located approximately directly above the portion of the base material body having an uneven shape has a pattern whose shape depends on the uneven shape.

With the above configuration, the DLC coating layer, which is made of a ta-C coating that is high-density, hard, and highly wear-resistant, can clearly impart a shape to the surface of the decorative component that is dependent on the uneven shape applied to the base material body.

The decorative member of the present invention may also be configured as follows: The thickness of the metal layer is 0.01 to 10 μm. According to the above configuration, by setting the thickness of the metal layer to 0.01 to 10 μm, the DLC coating layer can be formed in a state where it is properly adhered to the base material body.

1 is a schematic perspective view showing a decorative member according to an embodiment of the present invention; FIG. 2 is a schematic cross-sectional view showing a cross-sectional structure of a decorative member. 5A to 5C are process diagrams showing a manufacturing method of a decorative member.

The following describes an embodiment of the present invention with reference to the accompanying drawings.

(Decorative member 1)
First, the configuration of a decorative member 1 according to an embodiment of the present invention will be described. As shown in FIG. 1 , the decorative member 1 according to this embodiment is configured as a faucet pipe used in indoor plumbing environments. As shown in FIG. 2 , the decorative member 1 includes a base material body 2 made of a copper alloy, a metal layer 3 coated on the surface of the base material body 2, and a DLC coating layer 4 coated on the surface of the metal layer 3. A decorative pattern, i.e., a recess D, is formed on the surface of the decorative member 1. The recess D is formed by blasting the base material body 2 to form a shape having recesses 2A, and the recesses D have an uneven shape that depends on the recesses 2A. The decorative member 1 may also be configured without the recesses D.

(Base material body 2)
The base material body 2 is made of a copper alloy containing copper as a main component. Specifically, the base material body 2 is made of a copper alloy containing 50% or more copper, with the remainder being lead, zinc, tin, iron, nickel, and antimony. The base material body 2 may be made of pure copper, brass, bronze, cupronickel, or nickel silver. The specific shape of the base material body 2 is not particularly limited, and may be a tubular shape such as a circular pipe or a square pipe, a columnar shape such as a cylindrical or rectangular column, a spherical shape, or a plate shape.

After casting, the base material body 2 is machined to a predetermined shape, and then the surface is buffed and finished to a predetermined roughness (pre-process S1). As shown in Figure 3, the base material body 2 then undergoes a lead removal process S2 and a blasting process S3, where recesses 2A are recessed into the surface, forming the base shape for the recesses D that will become the decorative pattern described above (see Figure 2). The base material body 2 then undergoes a mirror-finishing process S4, where the entire surface, including the recesses 2A, is polished to a mirror-like finish. The base material body 2 then undergoes a cleaning process S5, where any dirt adhering to the surface is removed and the body is cleaned.

The base material body 2 then undergoes a metal layer deposition process S6, in which a metal layer 3 is deposited on its surface as an intermediate layer. The base material body 2 then undergoes a DLC coating layer deposition process S7, in which a DLC coating layer 4 classified as ta-C is deposited on the surface of the metal layer 3 that has been deposited on its surface. Each process is explained in detail below.

(Blast treatment step S3)
In the blasting process S3, first, a masking material (not shown) is attached to the surface of the base material body 2. Next, a blasting process is performed on the surface of the base material body 2 to which the masking material has been attached, and the surface portion of the base material body 2 other than the area covered with the masking material is recessed, thereby forming recesses 2A having a depth of 5 μm or less on the surface of the base material body 2.

The masking material can be a sheet made of a resin such as vinyl chloride or a rubber sheet with a hollowed-out shape corresponding to the shape of the recess 2A. The masking material may also be made of a resin such as vinyl chloride that is applied to the surface of the base material body 2 to form a coating with a hollowed-out shape corresponding to the shape of the recess 2A. By attaching the masking material to the surface of the base material body 2 and blasting the surface of the base material body 2, media (abrasive material) projected from a blasting device is struck against the hollowed-out portion of the masking material. This forms a recess 2A on the surface of the base material body 2 that corresponds to the hollowed-out shape of the masking material.

The portions of the surface of the base material body 2 that are covered with masking material are protected by the masking material and will not be recessed even when struck by media. The masking material preferably has a certain thickness to prevent the media from penetrating during the blasting process. The cutout shape of the masking material that corresponds to the shape of the recess 2A can be made into any desired shape, including figures, letters, patterns, and other shapes.

Blasting makes it possible to form recesses 2A of uniform depth on the surface of the base material body 2, even if the surface has a complex shape. Examples of blasting devices used for blasting include air blasting devices (compressor type, blower type, etc.) that use air to project media, and shot blasting devices that throw media using the rotational drive of a motor.

Examples of media (abrasive) materials include alumina (white, brown), silicon carbide (green, black), silica sand, iron, copper, stainless steel, zinc, aluminum, garnet, resin, and glass. The media may also be made of an elastic base material coated with fine abrasive grains. Examples of media shapes include spherical or acute-angled shapes. Examples of media particle sizes are 5 μm to 2 mm. The preferred media projection pressure is 0.1 to 0.5 MPa.

In order to achieve an appropriate surface roughness for the recesses 2A, it is preferable to use green silicon carbide as the material for the media. Furthermore, it is preferable for the media to have a particle size of 10 to 60 μm. The depth and surface roughness of the recesses 2A formed by blasting can be appropriately controlled by adjusting the particle size, shape, material, blasting pressure, blasting density, etc. of the media. After blasting, the masking material is removed from the surface of the base material body 2.

(Mirror finishing process S4)
In the mirror-finishing process S4, the entire surface of the base material body 2, including the recesses 2A, is subjected to a blasting process (mirror-finishing process) using media with even smaller particle sizes (for example, media such as SDC: metal-coated synthetic diamond #10000) to polish the entire surface of the base material body 2 to a mirror-like finish. This mirror-finishing process removes scratches that have been left on the surface of the base material body 2 by the previous buffing.

In the mirror-finishing process S4, the entire surface of the base material body 2, including the recesses 2A, is ground to a uniform depth of 2 μm or less. Therefore, even if the entire surface of the base material body 2, including the recesses 2A, is mirror-finished after the recesses 2A are formed on the surface of the base material body 2 in the previous blasting process S3, the decorative pattern of the recesses 2A will not disappear. This mirror-finishing process finishes the surface of the base material body 2 so that the arithmetic mean roughness (surface roughness) Ra specified in JIS B 0601-2001 is 0.1 μm or less.

The surface roughness of the base material body 2 that is finished by the mirror-finishing process can be appropriately controlled by adjusting the media particle size, shape, material, projection pressure, projection density, etc. The blasting process in this mirror-finishing process step S4 may also be a blasting process in which a masking material is applied to the surface of the base material body 2 to form recesses 2A. Alternatively, the recesses 2A may not be recessed into the surface of the base material body 2.

(Cleaning treatment step S5)
In the cleaning process S5, a cleaning method using a hydrocarbon-based cleaning liquid is used to remove and clean the contaminants adhering to the surface of the base material body 2. Note that the cleaning process S5 may be a process of cleaning the surface of the base material body 2 by a cleaning method using an aqueous cleaning liquid, a semi-aqueous cleaning liquid, or a chlorine-, bromine-, or fluorine-based solvent-based cleaning liquid.

In the cleaning process S5, first, a rough cleaning process is performed in which abrasives adhering to the surface of the base material body 2 are removed by water cleaning. Next, the main cleaning process is performed in which the surface of the base material body 2 is cleaned by emulsion cleaning. This emulsion cleaning process combines an ultrasonic cleaning method in which water is vibrated by ultrasonic waves, and a vacuum cleaning method in which the inside of the cleaning tank is repeatedly depressurized and then compressed to a near-vacuum state.

By combining emulsion cleaning with ultrasonic cleaning, it is possible to effectively clean dirt adhering to the base material body 2. Furthermore, by combining emulsion cleaning with vacuum cleaning, the cleaning liquid can reach blind holes and blind holes that cannot be cleaned under atmospheric pressure, making it possible to effectively clean even the small gaps in the base material body 2. In particular, by combining vacuum cleaning with ultrasonic cleaning, the effect of ultrasound is enhanced compared to atmospheric pressure, allowing for more effective cleaning. Note that in addition to or instead of the above cleaning methods, emulsion cleaning may be combined with degassing cleaning, rotational cleaning, swing cleaning, or shower cleaning.

By combining it with a degassing cleaning method, it is possible to further enhance the effectiveness of ultrasound when using ultrasonic cleaning methods. By combining the rotational cleaning method and the oscillation cleaning method, it is possible to physically create a flow of cleaning liquid, further enhancing the cleaning effect. It also makes it easier for the ultrasound to hit the surface of the base material body 2 evenly. Other methods for physically creating a flow of cleaning liquid include circulating or bubbling water. Furthermore, by combining it with a shower cleaning method, it is possible to spray cleaning liquid on the base material body 2 not only from above, but also from the sides and below, allowing for appropriate cleaning. Other cleaning methods include high-pressure jet cleaning, spray cleaning, and brush cleaning.

By performing the above cleaning, oil and other contaminants adhering to the surface of the base material body 2 are dissolved in the cleaning liquid and dispersed throughout the cleaning liquid. Furthermore, contaminants adhering to the base material body 2 are dissolved in the cleaning liquid and replaced by the cleaning liquid. Next, in the cleaning process step S5, a process of vapor cleaning is performed on the surface of the base material body 2 as a rinse. In vapor cleaning, the cleaning liquid is boiled and steam is used to clean contaminants remaining on the surface of the base material body 2 with even greater precision.

Next, in the cleaning process step S5, a drying process is performed to dry the cleaning liquid remaining on the surface of the base material body 2. This drying process is performed by so-called vacuum drying. Vacuum drying is a well-known method in which the pressure inside the cleaning tank is reduced to near vacuum, rapidly raising the boiling point of the cleaning liquid and causing the cleaning liquid to dry by bumping. By using vacuum drying, the pressure inside the cleaning tank, which has been heated by the previous vapor cleaning, is reduced, effectively promoting the bumping drying of the cleaning liquid, allowing for appropriate drying process that does not leave stains or other marks on the base material body 2.

The drying process may be performed by hot air drying or suction drying. Hot air drying is a known method of drying the surface of the base material body 2 by sending hot air into the cleaning tank. Suction drying is a known method of drying the surface of the base material body 2 by sending compressed hot air into the cleaning tank and simultaneously drawing it out from the opposite side with a suction blower. Hot air drying and suction drying can also be applied to cleaning tanks that use aqueous cleaning liquids and cannot be vacuum dried.

(Metal layer 3)
The metal layer 3 is interposed between the base material body 2 and the DLC coating layer 4 formed on its surface, and functions as an intermediate layer to improve adhesion between them. The metal layer 3 is composed of a first metal layer 3A formed directly on the base material body 2 and a second metal layer 3B formed in a laminated state on the first metal layer 3A. The first metal layer 3A and the second metal layer 3B may each be made of nickel, titanium, chromium, tungsten, or silicon. The metal layer 3 may also have a single-layer structure made of titanium, chromium, tungsten, or silicon. In particular, when the metal layer 3 is formed as a single-layer structure, it is preferably made of titanium, which has excellent corrosion resistance and excellent adhesion to the base material body 2 and the DLC coating layer 4.

When the metal layer 3 is composed of two layers, it is particularly preferable that the first metal layer 3A be made of nickel, which has excellent adhesion to the base material body 2, is hard, and has excellent corrosion resistance and heat resistance. It is particularly preferable that the second metal layer 3B be made of titanium, which has excellent corrosion resistance and excellent adhesion to the DLC coating layer 4. The thickness of the first metal layer 3A, which serves as the base for the second metal layer 3B, is preferably 3 μm or less. The thickness of the second metal layer 3B is preferably 0.1 to 1.0 μm.

The first metal layer 3A is deposited in a laminated state with a uniform thickness over the entire surface of the base material body 2. The second metal layer 3B is deposited in a laminated state with a uniform thickness over the entire surface of the first metal layer 3A. The first metal layer 3A may be deposited partially on the remaining surface of the base material body 2. The second metal layer 3B may also be deposited so that at least a portion of it is located on the first metal layer 3A, or may be deposited partially directly on the base material body 2. In other words, at least a portion of the first metal layer 3A may also be deposited directly and integrally on the back surface of the DLC coating layer 4.

In the metal layer deposition process S6, the first metal layer 3A and second metal layer 3B that make up the metal layer 3 are each deposited in a laminated layer on the surface of the base material body 2 by a sputtering method classified as a PVD (physical vapor deposition) method. In the metal layer deposition process S6, an ion bombardment process using argon ions is first performed to remove passivation films such as oxide and hydroxide films that appear on the surface of the base material body 2.

Next, using the sputtering method, a negative voltage is applied to the cathode target (film-forming material) in a vacuum containing an inert gas (argon gas), generating a glow discharge. Gas ions collide with the film-forming material, knocking out particles of the film-forming material, which then adhere and deposit on the surface of the base material body 2, forming a dense thin film. By depositing the first metal layer 3A and the second metal layer 3B that make up the metal layer 3 using the sputtering method, a dense, highly adhesive thin film can be formed on the surface of the base material body 2 without exposing the base material body 2 to liquid or high-temperature gas.

The first metal layer 3A and second metal layer 3B that make up the metal layer 3 may be formed on the surface of the base material body 2 by sputtering or arc ion plating. Arc ion plating is a well-known method in which film-forming material is evaporated in a vacuum and then ionized (ionized) by arc discharge, resulting in a positively charged film-forming material that is attracted to the surface of the base material body 2 to which a negative charge has been applied, forming a film.

(DLC coating layer 4)
In the DLC coating layer forming step S7, the DLC coating layer 4 is formed in a laminated form with a uniform thickness on the surface of the metal layer 3 formed on the surface of the base material body 2 by vacuum arc deposition, which is classified as a PVD (physical vapor deposition) method. The DLC coating layer 4 is formed by the vacuum arc deposition method as a coating layer classified as ta-C, which has the highest proportion of SP-3 structure among DLCs (diamond-like carbons) and is characterized by its highest density and hardness. ta-C is amorphous carbon with a proportion of SP-3 structure of 50% to 90% and a hydrogen content of 5% by mass or less.

More specifically, the DLC coating layer 4 is formed by the well-known FCVA (filtered cathodic vacuum arc) method, which is known as a vacuum arc deposition method that can produce films with minimal surface defects. The FCVA method is a well-known technique that filters droplets (macroparticles with an SP-2 structure or a similar composition structure), which are electrically neutral evaporated particles that can be emitted from solid graphite, the evaporation source of the cathode target, from the plasma during plasma transport, making them less likely to adhere to the coating when a ta-C coating is deposited on a workpiece by vacuum arc deposition.

By making it difficult for droplets to adhere to the coating, the coating surface can be formed with minimal irregularities, ensuring geometric uniformity (flatness) and chemical uniformity. As a result, the DLC coating layer 4 can be formed with a smooth surface and less deterioration of mechanical properties. The DLC coating layer 4 is preferably formed using the above-mentioned FCVA method so that the surface roughness Ra is 0.1 μm or less and the surface defects are 20% or less. Furthermore, the DLC coating layer 4 is preferably formed to a thickness of 0.5 to 5.0 μm and a Vickers hardness of 1,500 to 5,000 Hv. When the coating thickness is tens of nanometers to tens of μm, the hardness of the coating can be expressed as nanoindentation hardness.

The DLC coating layer 4 is preferably formed using the FCVA method as a ta-C coating with a surface layer refractive index of 1.5 to 3.0 at a wavelength of 550 nm. Methods for measuring the refractive index include the well-known spectroscopic ellipsometry method (an analytical method that measures changes in the polarization state of light incident on and reflected from a thin film) and optical interference method, which are known methods for determining the refractive index of thin films.

When the density of the DLC coating layer 4 is low, the refractive index of the surface layer of the DLC coating layer 4 is small because incident light is absorbed within the coating, reducing the amount of reflected light. Conversely, when the density of the DLC coating layer 4 is high, the refractive index of the surface layer of the DLC coating layer 4 is large because incident light is less easily absorbed within the coating, increasing the amount of reflected light.

Therefore, by providing a DLC coating layer 4 made of a high-density ta-C coating with the above-mentioned refractive index on the base material body 2, it is possible to appropriately prevent moisture penetration from the surface of the component. The DLC coating layer 4 is provided on the base material body 2 with the metal layer 3, which serves as an intermediate layer, in between, so that it is formed on the base material body 2 with good adhesion. This configuration appropriately enhances the moisture corrosion resistance of the decorative component 1.

By depositing the DLC coating layer 4, a high-density, hard, and highly wear-resistant coating layer is formed on the surface of the decorative component 1, as shown in Figure 2. The DLC coating layer 4 and the underlying metal layer 3 are each deposited in layers of uniform thickness on the surface of the base material body 2 using the vacuum arc deposition or sputtering methods described above. Therefore, the DLC coating layer 4 and the metal layer 3 are each deposited in a shape that forms a cylindrical decorative pattern, the shape of which corresponds to the recess 2A, approximately directly above the recess 2A recessed in the base material body 2.

The recesses D formed on the surface of the decorative member 1 are formed so that the coating does not build up at the inner corners of the recesses, but rather have a cylindrical shape with a clear outline that depends on the shape of the recesses 2A in the base material body 2. Therefore, even if the shape of the recesses 2A recessed into the base material body 2 is not set deep, a textured pattern with a clear outline can be formed on the surface of the decorative member 1. Because the DLC coating layer 4 is made of a ta-C coating, the recesses D formed on the surface of the decorative member 1 can be finished with a clear pattern that is high-density, hard, and highly wear-resistant, making the shape of the recesses D less likely to collapse.

Other Embodiments
Although one embodiment of the present invention has been described above, the present invention is not limited to the configuration shown in the above embodiment, and various modifications, additions, and deletions are possible within the scope of the present invention. For example, the decorative member of the present invention may be any member intended for use in an environment requiring corrosion resistance due to moisture, and may be applied to faucet piping used in indoor and outdoor wet environments, as well as to other than faucet piping.

REFERENCE SIGNS LIST 1 Decorative member 2 Base material body 2A Recess 3 Metal layer 3A First metal layer 3B Second metal layer 4 DLC coating layer D Recess S1 Pre-process S2 Lead removal process S3 Blasting process S4 Mirror finish process S5 Cleaning process S6 Metal layer deposition process S7 DLC coating layer deposition process

Claims (10)

It is a copper alloy decorative material used in faucets .
The substrate includes at least a copper alloy base body, a metal layer, and a DLC coating layer;
the metal layer is disposed between the DLC coating layer and the base material body;
the DLC coating layer is made of a ta-C coating having a refractive index of 1.5 to 3.0 at a wavelength of 550 nm at a surface layer portion;
The decorative member has a thickness of 0.5 to 5.0 μm. The decorative member according to claim 1, wherein the DLC coating layer contains 50 to 90% of the SP-3 structure and the Vickers hardness of the coating is 1,500 to 5,000 Hv. 3. The decorative member according to claim 1, wherein the DLC coating layer has a surface roughness Ra of 0.1 [mu]m or less. The decorative member according to any one of claims 1 to 3, wherein the DLC coating layer contains 5% by mass or less of hydrogen. The decorative member according to any one of claims 1 to 4, wherein the base material body is a copper alloy containing 50% or more copper, with the remainder consisting of lead, zinc, tin, iron, nickel, and antimony. The decorative member according to any one of claims 1 to 5, wherein the metal layer is a layer containing at least one metal selected from the group consisting of nickel, titanium, chromium, and tungsten. A decorative member according to any one of claims 1 to 6, wherein the metal layer includes a first metal layer and a second metal layer, and at least a portion of the second metal layer is disposed on the first metal layer. The decorative member according to any one of claims 1 to 7, wherein the refractive index of the surface layer of the DLC coating layer is 2.0 to 3.0 at a wavelength of 550 nm. The base material body has an uneven shape,
The decorative member according to any one of claims 1 to 7, wherein a portion of the DLC coating layer that is located approximately directly above a portion of the base material body that has the uneven shape has a pattern having a shape that depends on the uneven shape. The decorative member according to any one of claims 1 to 9, wherein the thickness of the metal layer is 0.01 to 10 μm.