Decorative member and timepiece

Abstract

To provide a decorative member having excellent hardness and friction coefficient and also having a blue appearance color.SOLUTION: Provided is a decorative member in which a first adhesion layer, a second adhesion layer, a hard layer, and an outermost layer are laminated in this order on a base material, the hard layer contains diamond-like carbon (hereinafter referred to as DLC), wherein the thickness is 0.4 μm or more and 1.2 μm or less, the outermost layer contains DLC, the hard layer formed on a laminate comprising the substrate, the first adhesive layer, and the second adhesive layer in that order has an L* value of 48 or more and 49 or less, an a* value of 0 or more and 0.1 or less, and the b* is 1.5 or more and 1.7 or less in the L*a*b* color coordinate system; and for the topmost layer on the surface of the decorative member, the L* value is 30 or more and 31 or less, the a* value is 1.1 or more and 1.7 or less; and b* is -11 or more and -9 or less in the L*a*b* color coordinate system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative member, a watch, and a method for manufacturing a decorative member. [Background technology]

[0002] Patent Document 1 describes an ornamental article having a substrate and a black hard coating made of diamond-like carbon (hereinafter referred to as DLC) formed on the substrate. Specifically, the black hard coating includes a gradient layer made of DLC, and the hydrogen content in the gradient layer increases with increasing distance from the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-53365 Summary of the Invention [Problem to be solved by the invention]

[0004] The decorative article of Patent Document 1 has excellent performance of the black hard coating, such as hardness and coefficient of friction, but has the problem that it cannot express external colors other than black.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a decorative member that has excellent hardness and coefficient of friction, and also has a blue appearance color. [Means for solving the problem]

[0006] The decorative member of the present invention is a decorative member in which a first adhesion layer, a second adhesion layer, a hard layer, and an outermost layer are laminated in this order on a substrate, wherein the first adhesion layer contains at least one element selected from Ti and Cr, the second adhesion layer contains at least one element selected from Si and Ge, the hard layer contains DLC and has a thickness of 0.4 μm or more and 1.2 μm or less, and the outermost layer contains DLC, and the hard layer formed on the laminate in which the substrate, the first adhesion layer, and the second adhesion layer are laminated in this order is L * a * b * L in the color space (CIE 1976) * The value is 48 or more and 49 or less, and a * The value is between 0 and 0.1, and b * The outermost layer of the decorative member has a value of 1.5 or more and 1.7 or less, and L * a * b * L in the color space (CIE 1976) * The value is between 30 and 31, and a * The value is 1.1 or more and 1.7 or less, and b * The value is between -11 and -9 inclusive. [Effects of the Invention]

[0007] The decorative member of the present invention has excellent hardness and coefficient of friction, and also has a blue appearance color. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a decorative member according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a decorative member according to a reference example. [Figure 3] FIG. 3 shows the results of SEM observation of the hard layer 14 of the decorative member obtained in the reference example. [Figure 4] FIG. 4 shows the results of SEM observation of the outermost layer 15 of the decorative member obtained in the example. [Figure 5]FIG. 5 shows an XPS spectrum measured on the hard layer 14 of the decorative member obtained in the reference example. [Figure 6] FIG. 6 shows an XPS spectrum measured on the outermost layer 15 of the decorative member obtained in the example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Modes (embodiments) for carrying out the present invention will be described in detail. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0010] <Decorative member according to the embodiment> Fig. 1 is a diagram illustrating a decorative member according to an embodiment. Fig. 1 is a schematic cross-sectional view of a decorative member 10. In the decorative member 10, a first adhesive layer 12, a second adhesive layer 13, a hard layer 14, and an outermost layer 15 are laminated in this order on a substrate 11.

[0011] The substrate 11 is a substrate formed from metal, ceramic, or plastic. Specific examples of metals (including alloys) include stainless steel, titanium, titanium alloys, copper, copper alloys, tungsten, or hardened stainless steel, titanium, or titanium alloys. These metals can be used alone or in combination of two or more. The shape of the substrate is not limited.

[0012] The first adhesion layer 12 contains at least one element selected from Ti and Cr. The presence of the first adhesion layer 12 can improve adhesion between the substrate 11 and a layer laminated on the first adhesion layer 12. From the viewpoint of adhesion, the thickness of the first adhesion layer 12 is preferably 0.1 μm or more and 0.2 μm or less.

[0013] The second adhesion layer 13 contains at least one element selected from Si and Ge. When the second adhesion layer 13 is provided, the adhesion between the first adhesion layer 12 and the layer containing DLC ​​stacked on the second adhesion layer 13 can be improved.

[0014] Specifically, the second adhesion layer 13 may contain at least one element selected from Si and Ge. For example, the second adhesion layer 13 may be formed of one of Si or Ge, or may be formed of Si and Ge. Furthermore, the second adhesion layer 13 may contain a nitride, carbide, or carbonitride of at least one element selected from Si and Ge. Examples of nitrides, carbides, and carbonitrides include SiN, SiC, SiCN, GeN, GeC, and GeCN.

[0015] From the viewpoint of adhesiveness, the second adhesive layer 13 preferably has a thickness of 0.1 μm or more and 0.2 μm or less.

[0016] The hard layer 14 includes DLC. DLC includes carbon and hydrogen and has a sp 3 carbon with bonds and sp corresponding to the graphite structure 2 It has an amorphous structure in which carbon atoms with bonds are randomly mixed.

[0017] The hard layer 14 has a thickness of 0.4 μm or more and 1.2 μm or less. A thickness within this range is preferable because it can exhibit the performance (suitable hardness and friction coefficient, etc.) of a DLC layer, which will be described later, and can also exhibit a black color, which will be described later.

[0018] The hard layer 14 is L * a * b * L in the color space (CIE 1976) * The value is 48 or more and 49 or less, and a * The value is between 0 and 0.1, and b * The value is 1.5 or more and 1.7 or less. * value, a * value and b *The value was measured for the hard layer 14 formed on a laminate in which the substrate 11, the first adhesive layer 12, and the second adhesive layer 13 were laminated in this order. * value, a * value and b * Values ​​within the above range indicate black. In this specification, "black" also includes dark gray.

[0019] The hard layer 14 has high hardness, and typically has a Vickers hardness HV of 1800 or more and 2200 or less. Here, the Vickers hardness HV is a value determined for the hard layer 14 formed on a laminate in which the substrate 11, the first adhesive layer 12, and the second adhesive layer 13 are laminated in this order. Specifically, the Vickers hardness is measured using a microindentation hardness tester (manufactured by FISCHER, HM2000XYp) by applying a Vickers indenter to the sample surface with a load of 5 mN, holding the load for 10 seconds, and then unloading the indenter, and calculating the Vickers hardness from the depth at which the Vickers indenter was inserted.

[0020] The hard layer 14 has a low coefficient of friction, and typically has a coefficient of friction (JIS R 1613) of 0.12 or more and 0.15 or less. Here, the coefficient of friction is a value determined for the hard layer 14 formed on a laminate in which the substrate 11, the first adhesion layer 12, and the second adhesion layer 13 are laminated in this order.

[0021] The hard layer 14 also has excellent abrasion resistance.

[0022] The outermost layer 15 contains DLC.

[0023] The thickness of the outermost layer 15 is preferably 0.05 μm or more and 0.07 μm or less. A thickness within this range is preferable because the decorative member 10 can exhibit excellent hardness and friction coefficient, as will be described later, and can also exhibit a blue color.

[0024] The outermost layer 15 is L * a * b * L in the color space (CIE 1976) * The value is between 30 and 31, and a* The value is 1.1 or more and 1.7 or less, and b * is between -11 and -9. * value, a * value and b * The values ​​were determined for the outermost layer 15 on the outermost surface of the decorative member 10. In other words, the values ​​were determined for the outermost layer 15 formed on a laminate in which the substrate 11, the first adhesive layer 12, the second adhesive layer 13, and the hard layer 14 were laminated in this order. * value, a * value and b * A value within the above range indicates a blue color. In this specification, the term "blue" specifically refers to a blackish blue or a dark navy blue.

[0025] Furthermore, the outermost layer 15 maintains the excellent hardness and friction coefficient of the hard layer 14, and typically has a numerical range of Vickers hardness HV and friction coefficient that is similar to that of the hard layer 14. Here, the Vickers hardness HV and friction coefficient are values ​​determined for the outermost layer 15 that is the outermost layer of the decorative member 10. In other words, they are values ​​determined for the outermost layer 15 formed on a laminate in which the substrate 11, first adhesion layer 12, second adhesion layer 13, and hard layer 14 are laminated in this order. Furthermore, the outermost layer 15 also has excellent abrasion resistance.

[0026] In this way, decorative member 10 employs a two-layer structure of DLC layers, consisting of hard layer 14 and outermost layer 15, which provides excellent hardness and friction coefficient, while also achieving a blue appearance. In other words, decorative member 10 combines durability with aesthetic appeal.

[0027] This is because the outermost layer 15, which has been structurally changed, also has the same sp 3 Ratio((sp 3 / (sp 3 +sp 2)), it is believed that excellent hardness of at least HV1400 or more can be maintained. In addition, since the outermost layer 15 contains more hydrogen than the hard layer 14, it is believed that thin film interference occurs, causing the color to become lighter (closer to transparency). This is believed to be why the blue appearance color can be expressed.

[0028] The decorative member 10 also has excellent gloss. This is thought to be because the particle size of the DLC contained in the outermost layer 15 is smaller than the particle size of the DLC contained in the hard layer 14. Furthermore, the two-layer structure of the decorative member 10, consisting of the hard layer 14 and the outermost layer 15, improves fingerprint resistance, corrosion resistance, and weather resistance, and the two-layer structure can also be used as a barrier film.

[0029] <Method of manufacturing decorative member according to the embodiment> The method for manufacturing a decorative member according to the embodiment is the same as the method for manufacturing a decorative member described above, that is, a method for manufacturing a decorative member 10 in which a first adhesion layer 12, a second adhesion layer 13, a hard layer 14, and an outermost layer 15 are laminated in this order on a substrate 11. The method for manufacturing a decorative member according to the embodiment includes a first adhesion layer forming step, a second adhesion layer forming step, a hard layer forming step, and an outermost layer forming step.

[0030] The first adhesion layer forming step is a step of forming a first adhesion layer 12 containing at least one element selected from Ti and Cr on the substrate 11. The second adhesion layer forming step is a step of forming a second adhesion layer 13 containing at least one element selected from Si and Ge on the first adhesion layer 12 formed in the first adhesion layer forming step. These steps can be specifically performed by a sputtering method, an arc ion plating method, or an ion plating method.

[0031] The hard layer formation process is a process of forming a hard layer 14 containing DLC ​​on the second adhesion layer 13 formed in the second adhesion layer formation process by applying a negative bias voltage of 2 kV or more and 5 kV or less, more preferably 3.5 kV, to the substrate 11 on which the first adhesion layer 12 and the second adhesion layer 13 have been formed by the plasma CVD method.

[0032] Specifically, in the hard layer formation process, a voltage in the above range is applied to the substrate 11, which is set in a vacuum device and on which the second adhesive layer 13 has been formed. This converts the gas containing the source material into plasma, and the source material is deposited on the substrate to form the hard layer 14. Hydrocarbon gases such as methane, acetylene, and benzene are preferably used as the gas containing the source material. This allows the formation of a layer containing DLC ​​containing carbon and hydrogen.

[0033] By appropriately adjusting the time for applying the voltage (film formation time), it is possible to form a hard layer 14 having a thickness within the above-mentioned specific range. The film formation time is, for example, 60 minutes or more and 120 minutes or less. Furthermore, by applying a voltage within the above-mentioned specific range during the appropriately adjusted film formation time, L * value, a * value and b * The value can be adjusted to fall within the above range. That is, a black hard layer 14 can be formed. Furthermore, by applying a voltage within the above specific range for the appropriately adjusted film formation time, a hard layer 14 having a suitable hardness and friction coefficient can be formed.

[0034] The outermost layer forming process is a process of forming an outermost layer 15 containing DLC ​​on the hard layer 14 formed in the hard layer forming process by applying a negative bias voltage of 0.05 kV or more and 0.4 kV or less to the substrate 11 on which the first adhesion layer 12, the second adhesion layer 13 and the hard layer 14 have been formed by the plasma CVD method.

[0035] Specifically, in the outermost layer forming step, a voltage in the above range is applied to the substrate 11, which is set in a vacuum device and on which the hard layer 14 has been formed. This converts the gas containing the source material into plasma, and the source material is deposited on the substrate to form the outermost layer 15. The gas containing the source material is preferably the same as that used in the hard layer forming step. This allows the formation of a layer containing DLC ​​containing carbon and hydrogen.

[0036] By appropriately adjusting the time for applying the voltage (film formation time), it is possible to form the outermost layer 15 having a thickness within the above-mentioned specific range. The film formation time is, for example, 7 minutes or more and 11 minutes or less. Furthermore, by applying a voltage within the above-mentioned specific range during the appropriately adjusted film formation time, L * value, a * value and b * The value can be adjusted to fall within the above range. That is, a blue outermost layer 15 can be formed. Furthermore, by applying a voltage within the above specific range for the appropriately adjusted film formation time, an outermost layer 15 can be formed that maintains a suitable hardness and coefficient of friction.

[0037] <Modification> In the decorative member according to the embodiment, a gradient layer containing DLC ​​may be provided between the hard layer 14 and the outermost layer 15. In the gradient layer, for example, the hydrogen content or sp 3 The ratio changes in the thickness direction. The provision of a gradient layer can improve color reproducibility, etc. This modification can be produced by providing a gradient layer formation process between the hard layer formation process and the outermost layer formation process. The gradient layer can be formed by gradually changing the negative bias voltage from the start to the end of its formation.

[0038] <Watch according to the embodiment> The timepiece according to the embodiment includes the decorative member described above. The timepiece according to the embodiment is at least partially constructed from the decorative member described above. The timepiece may be any of a wristwatch, a table clock, and a wall clock. The timepiece may also be any of a photovoltaic-powered timepiece, a heat-powered timepiece, a radio-wave-receiving self-correcting timepiece, a mechanical timepiece, and a general electronic timepiece. Such timepieces are manufactured by known methods using the decorative member described above. Wristwatches in particular tend to be easily scratched by rubbing against a shirt or by hitting a desk, wall, etc. The timepiece according to the embodiment includes the decorative member described above, and therefore has excellent durability and can maintain its blue color tone and appearance in a very beautiful condition. The decorative members described above may also be included in decorative items other than watches. Examples of such decorative items include necklaces, pendants, brooches, and eyeglasses. These may be partially or entirely composed of the decorative members described above. Because the decorative items contain the decorative members described above, they are highly durable and can maintain their blue color and appearance in a very beautiful condition.

[0039] Based on the above, the present invention relates to the following. [1] A decorative member in which a first adhesive layer, a second adhesive layer, a hard layer, and an outermost layer are laminated in this order on a substrate, wherein the first adhesive layer contains at least one element selected from Ti and Cr, the second adhesive layer contains at least one element selected from Si and Ge, the hard layer contains DLC, and has a thickness of 0.4 μm or more and 1.2 μm or less, and the outermost layer contains DLC. * a * b * L in the color space (CIE 1976) * The value is 48 or more and 49 or less, and a * The value is between 0 and 0.1, and b * The value is 1.5 or more and 1.7 or less, and the outermost layer on the outermost surface of the decorative member is * a * b * L in the color space (CIE 1976) * The value is between 30 and 31, and a * The value is 1.1 or more and 1.7 or less, and b * Decorative elements with a value between -11 and -9. [2] The decorative member according to [1], wherein the outermost layer has a thickness of 0.05 μm or more and 0.07 μm or less. The decorative member of [1] or [2] above has excellent hardness and friction coefficient, and also has a blue appearance color. [3] A watch including the decorative member described in [1] or [2]. The above watch is highly durable and maintains its blue color and appearance in very good condition. [4] A method for manufacturing a decorative member having a first adhesion layer, a second adhesion layer, a hard layer, and an outermost layer laminated in this order on a substrate, the method comprising: a first adhesion layer forming step of forming the first adhesion layer containing at least one element selected from Ti and Cr on the substrate; a second adhesion layer forming step of forming the second adhesion layer containing at least one element selected from Si and Ge on the first adhesion layer formed in the first adhesion layer forming step; and applying a voltage of 2 kV or more to the substrate on which the first adhesion layer and the second adhesion layer have been formed by a plasma CVD method on the second adhesion layer formed in the second adhesion layer forming step. a hard layer forming step of forming the hard layer containing DLC ​​while applying a negative bias voltage of 5 kV or less; and an outermost layer forming step of forming the outermost layer containing DLC ​​on the hard layer formed in the hard layer forming step by applying a negative bias voltage of 0.05 kV to 0.4 kV to the substrate on which the first adhesive layer, the second adhesive layer, and the hard layer have been formed by a plasma CVD method, wherein the hard layer has a thickness of 0.4 μm to 1.2 μm, and the hard layer formed on the laminate in which the substrate, the first adhesive layer, and the second adhesive layer are laminated in this order is * a * b * L in the color space (CIE 1976) * The value is 48 or more and 49 or less, and a * The value is between 0 and 0.1, and b * The value is 1.5 or more and 1.7 or less, and the outermost layer on the outermost surface of the decorative member is * a * b * L in the color space (CIE 1976) * The value is between 30 and 31, and a * The value is 1.1 or more and 1.7 or less, and b * A method for manufacturing a decorative member having a value of -11 or more and -9 or less. According to the above-described method for manufacturing a decorative member, a decorative member having excellent hardness and coefficient of friction as well as a blue appearance color can be obtained.

[0040] [Example] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples.

[0041] [Reference example] Fig. 2 is a diagram illustrating a decorative member of a reference example. Fig. 2 is a schematic cross-sectional view of a decorative member 20. In the decorative member 20, a first adhesive layer 12 (Ti layer), a second adhesive layer 13 (Si layer), and a hard layer 14 (DLC layer) were formed on a base material 11 (SUS substrate). In the first adhesion layer forming step, a 0.2 μm thick Ti layer was formed on the SUS substrate by sputtering, and in the second adhesion layer forming step, a 0.2 μm thick Si layer was formed on the Ti layer by sputtering. In the hard layer formation process, a hard layer 14 containing DLC ​​was formed on the Si layer by plasma CVD. Specifically, the substrate on which the Si layer had been formed was placed in a vacuum chamber, and benzene was introduced into the chamber as a raw material gas in addition to Ar gas as an inert gas. While maintaining the pressure inside the chamber at 0.3 Pa, the benzene was decomposed by plasma CVD to form a DLC layer (hard layer 14) on the Si layer. The negative bias voltage was kept constant at 3.5 kV from the start to the end of film formation. The film formation time in the outermost layer formation process was 90 minutes. In this way, the decorative member 20 was produced.

[0042] [Example] In this example, a decorative member 10 shown in Fig. 1 was produced. That is, a first adhesive layer 12 (Ti layer), a second adhesive layer 13 (Si layer), a hard layer 14 (DLC layer), and an outermost layer 15 (DLC layer) were produced on a base material 11 (SUS substrate). The steps up to the hard layer formation step were carried out in the same manner as in the reference example. Next, in the outermost layer formation step, a DLC-containing outermost layer 15 was formed on the hard layer 14 by plasma CVD. Specifically, in the outermost layer formation step, the substrate on which the hard layer 14 had been formed and placed in the vacuum chamber was used as is. Following the hard layer formation step, benzene was introduced as a raw material gas in addition to Ar gas as an inert gas into the vacuum chamber, and the pressure inside the chamber was maintained at 0.4 Pa. Then, as in the hard layer formation step, benzene was decomposed by plasma CVD to form a DLC layer (outermost layer 15) on the hard layer 14. The negative voltage applied to the substrate in the hard layer formation step was instantly switched to the negative voltage applied to the substrate in the outermost layer formation step, and the negative bias voltage was kept constant at 0.1 kV from the start of film formation to the end of film formation. The film formation time in the outermost layer formation step was 10 minutes. In this manner, the decorative member 10 was produced.

[0043] <Evaluation method> [Color tone] Regarding the hard layer 14 of the decorative member obtained in the reference example and the outermost layer 15 of the decorative member obtained in the example, * a * b * L in the color space (CIE 1976) * value, a * value and b * Specifically, a spectrophotometer (CM-2600d, manufactured by Konica Minolta) was used, and measurements were made with a D65 light source and a 10° viewing angle. [Particle size] The surface of the hard layer 14 of the decorative member obtained in the Reference Example and the surface of the outermost layer 15 of the decorative member obtained in the Example were observed using an SEM. Specifically, using a Carl Zeiss Gemini 300, the observations were performed at a sample incident voltage of 5 kV, a WD of 6 mm, and a magnification of 50,000. From this, the particle size range was determined. [Hydrogen content] The hydrogen content of the hard layer 14 of the decorative member obtained in the reference example and the outermost layer 15 of the decorative member obtained in the example was measured by RBS-ERDA Rutherford Backscattering Spectrometry - Elastic Recoil Detection Analysis using a Pelletron 3SDH manufactured by National Electrostatics Corporation. [sp 3 Ratio (sp 3 / (sp 3 +sp 2 )) The XPS C1s spectrum was obtained for the hard layer 14 of the decorative member obtained in the reference example and the outermost layer 15 of the decorative member obtained in the example. Specifically, an XPS X-ray photoelectron spectrometer (Nexsa, manufactured by Thermo Fisher Scientific) was used to perform waveform separation of the narrow spectrum of C (carbon) to obtain sp 3 and sp 2 The ratio was measured. [Hardness] The hardness of the hard layer 14 of the decorative member obtained in the Reference Example and the outermost layer 15 of the decorative member obtained in the Example was measured. Specifically, the Vickers hardness HV was measured using a microindentation hardness tester (manufactured by Fischer, HM2000XYp). A Vickers indenter was used as the measuring probe, and a load of 5 mN was applied for 10 seconds, after which the load was released, and the hardness was calculated from the depth of the Vickers indenter insertion. [Coefficient of friction] The coefficient of friction (JIS R 1613) was determined for the hard layer 14 of the decorative member obtained in the Reference Example and the outermost layer 15 of the decorative member obtained in the Example. Specifically, a ball-on-disk test was conducted using a multi-function friction tester (manufactured by Bruker, UMT Tribo Lab) under conditions of a load of 5 N, a linear velocity of 0.1 m / s, a sliding radius of 5 mm, and a sliding distance of 1,000 m. A 5 mm diameter SUS304 ball was used on the ball side, and the target DLC film was formed on SUS316L on the disk side.

[0044] <Evaluation results> Fig. 3 shows the results of SEM observation of the hard layer 14 of the decorative member obtained in the reference example, and Fig. 4 shows the results of SEM observation of the outermost layer 15 of the decorative member obtained in the example. Fig. 5 shows an XPS spectrum measured for hard layer 14 of a decorative member obtained in a reference example, and Fig. 6 shows an XPS spectrum measured for outermost layer 15 of a decorative member obtained in an example. The evaluation results are summarized in Table 1.

[0045] [Table 1] [Explanation of symbols]

[0046] 10, 20 Decorative materials 11 Base material 12 First adhesive layer 13 Second adhesive layer 14 Hard layer 15 Top layer

Claims

1. A decorative member comprising a substrate and a first adhesive layer, a second adhesive layer, a hard layer, and an outermost layer laminated in this order on the substrate; the first adhesion layer contains at least one element selected from Ti and Cr, the second adhesion layer contains at least one element selected from Si and Ge, the hard layer contains diamond-like carbon and has a thickness of 0.4 μm or more and 1.2 μm or less; the outermost layer contains diamond-like carbon, Regarding the hard layer formed on the laminate in which the substrate, the first adhesive layer, and the second adhesive layer are laminated in this order, L * a * b * L in the color system (CIE 1976) * The value is 48 or more and 49 or less, and a * The value is 0 or more and 0.1 or less, and b * The value is 1.5 or more and 1.7 or less, Regarding the outermost layer on the outermost surface of the decorative member, L * a * b * L in the color system (CIE 1976) * The value is 30 or more and 31 or less, and a * The value is 1.1 or more and 1.7 or less, and b * The value is between -11 and -9, The particle diameter of the diamond-like carbon contained in the outermost layer is smaller than the particle diameter of the diamond-like carbon contained in the hard layer. Decorative material.

2. The outermost layer has a thickness of 0.05 μm or more and 0.07 μm or less. The decorative member according to claim 1 .

3. The decorative member according to claim 1 or 2 is included. clock.

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