JPH0222452A - Ornamental member - Google Patents

Abstract

PURPOSE:To produce an ornamental member resembling stainless steel material in color tone and free from scratches at a low cost by forming a hard film consisting of a lower layer composed principally of metallic chromium and an upper layer composed principally of chromium carbonitride on a substrate. CONSTITUTION:A substrate 1 composed of SUS 304 is cleaned in a vacuum tank, and then, the inside of the vacuum tank is regulated to about 1X10<-4>Torr and a lower layer 2 composed principally of metallic chromium is formed on the substrate 1 by an ion plating method. Subsequently, nitrogen gas and acetylene gas are rapidly introduced and an upper layer 3 composed principally of chromium carbonitride is formed to about 0.15-3.0mu thickness. By this method, an ornamental member in which the surface of the upper layer 3 has a color tone resembling, very closely, that of stainless steel where L*, a*, and b* satisfy the relations in 65%<=L*<=90%, -3<=a*<=5, and -5<=b*<=10, respectively, in the (CIE1976)L*, a*, and b* color space specified by JIS Z8105-2068 and which has wear resistance, scratch resistance, high adhesive strength, and high hardness can be inexpensively obtained. This member is useful, e.g., for outer ornament parts for watch.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a decorative member using, for example, an ion blating method, and more particularly to a decorative member coated with chromium carbonitride and having a color tone very similar to stainless steel.

[Invention (already required)]

The present invention provides decorative members with unprecedented abrasion resistance, scratch resistance, high adhesion, and high hardness by using metallic chromium as an evaporation source and using an ion blasting method in an atmosphere containing, for example, nitrogen gas and hydrocarbon gas. The object of the present invention is to provide a decorative member having an appearance color tone equivalent to that of stainless steel at a low cost.

[Conventional technology]

Conventionally, for example, nearly 90% of the external color tones of exterior parts for watches, which are decorative members, have been gold or white from the standpoint of decoration. Therefore, as a white finish, the stainless steel material was first polished and the final appearance was made to match the color tone of the stainless steel itself. In addition, for materials with poor corrosion resistance such as brass and nickel silver, after surface treatment with Cu plating or Ni plating, palladium alloy, rhodium, etc.
Silver and other materials have been treated with wet plating to give them a white finish.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, when the stainless steel material is used as it is, for example, as an exterior part for a watch, the hardness of the stainless steel itself is Hv 180 to 2 in terms of Vickers hardness.
0.00, it has the disadvantage that when consumers carry it around, it will get scratched in just a few months, making it impossible to maintain its original decorative appearance for a long period of time. In addition, plating of palladium alloy, rhodium, silver, etc. on brass and nickel silver materials by wet plating is generally done to a thickness of several microns for watch exterior parts, but because the plating thickness is thin, the hardness is low. Similar to the stainless steel material mentioned above, it has the drawback of becoming severely damaged by long-term use and deteriorating its appearance. Furthermore, since palladium alloys, rhodium, silver, etc. are extremely expensive, there is a problem in that it is difficult to reduce costs.

Therefore, the present invention is intended to solve these problems, and its purpose is to improve wear resistance and scratch resistance by using highly hard chromium carbide, chromium nitride, and chromium carbonitride coatings created by, for example, the ion blating method. It is an object of the present invention to provide a technology that satisfies the above requirements, has a white tone equivalent to that of conventional stainless steel materials, and can be used as an inexpensive decorative member.

[Means for solving problems]

The decorative member of the present invention is a decorative member on which a hard coating is formed, wherein the hard coating includes at least a lower layer containing metallic chromium as a main component and a chromium carbonitride formed on the lower layer as a main component. A decorative member comprising upper layers.

[Effect]

According to the above-described structure of the present invention, a metal chromium layer as an active lower layer made of pure metal is formed on the first layer on the substrate (hereinafter referred to as the substrate) of the decorative member by, for example, an ion-blating method, so that it adheres closely to the substrate. By ensuring the properties and then proceeding with carbonization and nitridation to form chromium carbonitride as an upper layer,
Ensure adhesion between the lower layer and the upper layer. This two-layer structure ensures adhesion quality as an exterior part for a watch.

Next, by forming a three-layer structure in which a mixed region of the lower layer and the upper layer is provided between the lower layer and the upper layer, the adhesion is further improved compared to the two-layer structure. This is because forming a mixed region of metallic chromium and chromium carbonitride as an intermediate layer from the metallic chromium layer to the carbonitride chromium layer is effective against mechanical strain and thermal shock on the hard coating. Metallic chromium is essential for functioning as a stress absorption layer and buffer layer. With the above structure, the total adhesion of the hard coating to the substrate is further improved compared to a two-layer structure.

In order to further improve the adhesion of the two-layer structure, it is necessary to subdivide the hard coating into a five-layer structure to reduce the difference in response between each layer.

In other words, an active metallic chromium layer is formed using a pure gold layer as the first layer on the substrate to ensure complete adhesion to the substrate, and a nitriding or carbonizing reaction is carried out midway through the formation of the metallic chromium layer to form the second layer. Three fully developed chromium nitride or chromium carbide layers are formed. Next, during the formation of chromium nitride or chromium carbide, a nitriding reaction and a carbonizing reaction proceed simultaneously to form a fourth layer, and the final hard coating surface portion becomes a sufficiently advanced chromium carbonitride layer. The third layer and the second layer, the second layer and the third layer, the third layer and the fourth layer, and the fourth layer and the fifth layer always share about 50% of the same composition metal between the layers, so-called diffusion. By exhibiting this condition, the adhesion between the eyebrows improves dramatically. Furthermore, a mixed region of metallic chromium and chromium carbide or a mixed region of metallic chromium and chromium nitride as an intermediate layer from the third layer to the third layer, and a mixed region of metallic chromium and chromium nitride as an intermediate layer from the third layer to the fifth layer. A mixed region of chromium carbide and chromium carbonitride or a mixed region of chromium nitride and chromium carbonitride On the other hand, it acts as a stress transmission layer, and the lowest metal chromium layer is essential because it acts as a stress absorption layer and a buffer layer. With the above structure, the brittleness peculiar to the hard coating caused by ion blating is further improved, and the adhesion of the total hard coating to the substrate is more completely ensured than in the three-layer structure. The color tone of the hard coating is due to the unique characteristics of the upper layer of chromium carbonitride, so it can be applied in two layers, three layers,
and is completely unaffected by the difference in the structure of the five layers.

The hard coating of chromium carbonitride is produced by the ion-blating method, so it has a hardness of Hv -1500 or more, and can prevent scratches of several microns in practical use. In addition, since the color tone of the coating has a metallic luster and is similar to stainless steel, for example, when the present invention is applied to exterior parts for watches, the combination of exterior parts for watches and other parts made of stainless steel material The present invention can also be applied to the entire surface of a mobile watch, including the band, or only to parts that are particularly susceptible to scratches due to its shape.The chromium carbonitride layer of the present invention Thickness is 0.1
The range of 5 μm to 3.0 μm is more preferable in terms of color tone and hardness, and the surface of the chromium carbonitride layer in this range is defined by JIS Z2068 (CIF 197
6) L”, a”b in L”, a” b” color space
"respectively 65%≦L" 590%, -3≦a"
It is characterized by having a color tone that satisfies the following relationships: ≦5, -5≦b7≦10.

At this color tone, the hard coating of chromium carbonitride shines with a metallic luster, with a color tone that closely resembles that of stainless steel. Lo
If the value is too small, the brightness of the hard coating surface will be low (and it will become blackish), the gloss of the hard coating will be unsatisfactory, and L
If ' is too high, the brightness will be too high and it will just become glittery, so L0 is preferably in the range of 65% to 90%, most preferably 72% to 83%, and the ao is small in the color tone of the hard coating surface. If b* is too large, it will become too greenish; on the other hand, if b* is too large, it will become too bluish, and if b* is too large, it will become too yellowish, so a"b" -3≦a0≦5, respectively
The range of −5≦b*≦IO is preferable, and moreover, −1≦a*≦
2, -*≦b*≦6 is most preferred. Next, the hard coating of chromium carbonitride with a stainless steel color is produced by the ion-blating method, which is a compound of chromium, carbon, and nitrogen that is produced using chromium or chromium alloy as an evaporation source and nitrogen-based gas and hydrocarbon-based gas as reactive gases. may be applicable. Furthermore, by adding a trace amount of oxygen gas to nitrogen gas or hydrocarbon gas as a reactive gas, chromium, carbon, nitrogen,
Compounds of oxygen are also applicable. In both cases, the total thickness of the hard coating with a color similar to stainless steel produced by ion blating is preferably in the range of 0.15 μm to 5.0 μm in terms of productivity and functionality (abrasion resistance, scratch resistance, adhesion), and The optimum range is 1 μm to 2 μm. In addition to the ion blasting method, methods for producing hard coatings include sputtering, chemical vapor deposition (CVD), and plasma chemical vapor deposition (CVD), which are similar physical vapor deposition methods.
PCVD) etc. can be easily applied.

The substrate of the decorative member of the present invention may be of any material as long as it can withstand the temperature during the ion-blating process, for example, when using the ion-blating method. For example, ceramic, carbide, N1-based alloy, Co-based alloy, stainless steel, copper alloy, zinc, zinc alloy, plastic, etc. can be used. Since most of the hard coatings obtained by the ion blating method have relatively pinholes, it is necessary to satisfy the corrosion resistance quality before coating the hard coating 11. Ceramic, carbide Ni
Substrates such as base alloys, Co5 alloys, and stainless steel have good corrosion resistance, so base plating is basically not required, but stainless steel substrates with a high free-cutting component such as S (sulfur) have slightly poor corrosion resistance. Therefore, gold, gold alloy,
It is necessary to ensure the corrosion resistance of the substrate by using a single layer or a stack of several types of plating layers of chromium, palladium, palladium alloy, ruthenium, or rhodium. In addition, when copper alloy, zinc, or zinc alloy is used as a substrate, copper, Ni, or Ni alloy is plated in a single layer or in layers, and then gold, gold alloy, chromium, palladium, palladium alloy, rhodium, ruthenium, etc. are plated. It is necessary to ensure corrosion resistance by layering or laminating several types. In particular, for copper alloy, zinc, and zinc alloy substrates, the above-mentioned bottom plating is applied before ion blating to prevent the substrate material from being directly exposed to high temperature and high vacuum atmosphere during ion blating. It is possible to prevent the temperature rise inside the substrate material and prevent the occurrence of blisters due to the dezincing phenomenon. In addition, when plastic is used for the substrate, it is common to perform a treatment such as N1 by electroless plating prior to the plating process similar to plating for sub-bonding to the copper alloy, zinc, and zinc alloy substrates mentioned above. . Plastic substrates have a low melting point and are organic materials, so gas is easily blown out due to the temperature rise during ion blating treatment, and poor adhesion with the ion blating film is likely to occur frequently.To prevent poor adhesion, Tsukemetsuki is essential.

In terms of productivity and functionality, the optimal thickness of the underplating is 2 μm to 10 μm, whether it is a single layer or a laminated layer, but the basic quality does not change even if the range is expanded to 0.2 μm to 20 μm.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
Figures 2, 3 and 4 are 5US304 of the present invention.
FIG. 2 is a cross-sectional view of an exterior part for a watch made of. Made of materials such as ceramic, carbide, Nf-based alloy, CO-based alloy, stainless steel, copper alloy, zinc, zinc alloy, plastic, etc., stainless steel is coated on the watch case substrate, which has been appropriately subplated using the ion-blating method. Prior to the process of producing a hard coating of chromium carbonitride with a color tone very similar to
Argon gas was introduced into the vacuum chamber, maintained at a pressure of 0.02 Lorr, and ion bombardment was performed for 5 minutes with a negative voltage of 0.5 kV applied to the substrate to clean the surface of the watch case substrate. Next, after exhausting the argon gas and returning the vacuum chamber to I
kv is applied to generate plasma, and ionized metallic chromium is generated on the substrate. In this state, a lower layer 2 containing metallic chromium as a main component is generated. Next, nitrogen gas and acetylene gas are gradually introduced into the vacuum chamber at various fixed ratios,
Finally, various constant pressures are introduced. A hard coating formed during the time until the gas stabilizes at a constant pressure is a mixed layer 4 of metallic chromium and chromium carbonitride.

Next, after the mixed gas of nitrogen and acetylene reaches a constant pressure, the ion blating treatment is continued for a certain period of time to finally generate the upper layer 3 mainly composed of chromium carbonitride.
Layer 2 (lower layer) mainly composed of metallic chromium as shown in the figure
Mixed layer 4 of metallic chromium and chromium carbonitride, and layer 1 whose main component is chromium carbonitride! A hard coating with a three-layer structure formed from I3 (upper N) was obtained. By rapidly introducing nitrogen gas and acetylene gas into the vacuum chamber, a layer 2 (lower layer) mainly composed of metallic chromium and chromium carbonitride as shown in FIG. 1 without the mixed layer 4 is formed. A structure was created in which a hard coating with a two-layer structure was formed from N3C (upper layer).

After forming the lower layer 2 containing metallic chromium as a main component, a constant amount of nitrogen gas or acetylene gas is gradually introduced into the vacuum chamber until the pressure reaches a constant pressure of 2.times.10@-'torr. A layer formed during the time until the gas stabilizes at a constant pressure is a mixed layer 5 of metallic chromium and chromium nitride or a mixed layer 8 of metallic chromium and chromium carbide.

Next, after the nitrogen or acetylene gas pressure reaches a constant pressure, the ion blating treatment is continued for a certain period of time to form a layer 6 mainly composed of chromium nitride or a layer 9 mainly composed of chromium carbide. A mixed gas of nitrogen gas and acetylene gas is gradually introduced into the vacuum layer at various constant ratios, and finally to various constant pressures. The coating formed during the time until the mixed gas pressure stabilizes at a constant pressure is the mixed layer 7 of chromium nitride and chromium carbonitride or the mixed layer 10 of chromium carbide and chromium carbonitride. Finally, after the mixed gas of nitrogen and acetylene reaches a constant pressure, the ion blating treatment is continued for a certain period of time to finally generate N3 whose main component is chromium carbonitride. A hard coating with a layered structure was obtained.

By the above method, a total of 48 samples of Examples 1 to 32 of the present invention and Comparative Examples 1 to 26 were formed with hard coatings for each of the hard coating configurations shown in FIGS. 1 to 4. After completing the mobile watch using the case, the results of inspection for color tone, corrosion resistance, abrasion resistance, and adhesion, as well as conditions for forming the hard coating, etc., are summarized in Tables 1 to 9.

Table 1 shows the layer mainly composed of metallic chromium (lower Jif) 2 and the layer mainly composed of chromium carbonitride (upper l) shown in Figure 1.
i) Examples 1 to 8 of the present invention in a two-layer structure with 3,
The test results and hard film forming conditions for samples of Comparative Examples 1 to 5 are shown.

Table 2 shows the formation time of each layer and the hard coating J7 corresponding to the samples in Table 1.

Table 3 shows Examples 9 to 16 of the present invention and Comparative Examples 6 to 12 in the three-layer structure of the lower N2 shown in FIG. 2, the mixed layer 4 of metal chromium and chromium carbonitride, and the upper layer 3. The test results of the sample and the conditions for creating the hard film are shown.

Table 4 shows the formation time and hard coating thickness of each layer corresponding to the samples in Table 3.

Table 5 shows the lower layer 2 shown in FIG. 3, the mixed layer 5 of metallic chromium and chromium nitride, N6 whose main component is chromium nitride, the mixed layer 7 of chromium nitride and chromium carbonitride, and the upper layer 3.
The test results and hard coating preparation conditions for samples of Examples 17 to 24 of the present invention and Comparative Examples 13 to 19 in the five-layer structure are shown below.

Table 6 shows the formation time and hard coating thickness of each layer corresponding to the samples in Table 5.

Table 7 shows the lower 712 shown in FIG.
Examples 25 to 32 of the present invention in a five-layer structure of i6, a mixed layer 7 of chromium nitride and chromium carbonitride, and the upper layer 2
, the test results and hard coating formation conditions for samples of Comparative Examples 20 to 26 are shown.

Table 8 shows the formation time and hard coating thickness of each layer corresponding to the samples in Table 7.

Table 9 shows Examples 1 to 32 of the present invention and Comparative Examples 1 to 26.
Among the samples shown in Tables 1 to 8 above, the bottom part shows the plating structure and plating thickness for cases with subplating.

In addition, "processing time (minutes)" listed in Tables 1, 3, 5, and 7 indicates the chromium deposition time during ion blasting, and rNz /Cm H,J indicates the chromium deposition time during upper layer formation. , indicates the flow rate ratio of NZ and C□H2 when the gas pressure is constant;
"Gas pressure" indicates the vacuum chamber pressure when the single or mixed gas of N2, C, and H is stable during the formation of the upper layer, and "film thickness" indicates the total thickness of the lower layer to the upper layer.

Table 10 also shows evaluation criteria for the evaluation characteristics in Tables 1, 3, 5, and 7 above.

Table 10 Next, the method for confirming each characteristic will be described below.

The color tone of each hard coating surface is JIS Z 810520.
JISZ 081 using standard light C specified in 14
The spectral reflectance specified by 05-1013 was determined, and this value was converted into (CIE1976) L"a"b" color space and quantified.

In addition, color tone was visually judged and compared with stainless steel. The film thickness was determined by shadowing the hard film and measuring the step formed at that time using a micro-roughness measuring device manufactured by Kosaka Institute.

Furthermore, the first layer shown in Table 2, Table 4, Table 6, and Table 8
Regarding the fifth layer, the cross section of the hard coating was analyzed by X-rays to determine the thickness of each layer. The hardness was measured using a Milo Vickers hardness tester under a load of 10 gr. In addition, wear resistance was evaluated by checking the degree of wear of the hard coating on the side of the watch case by placing the side of the watch case in close contact with cowhide and applying a load of 500 gr to the watch case, and abrading the hard coating on the side of the watch case 30,000 times with a 10 cm stroke. Adhesion was determined by applying a compressive load to the watch case from both ends using high-speed steel so that the bent portion was 90° or more, and examining the degree of peeling of the hard coating at the bent portion. For corrosion resistance, artificial sweat and artificial seawater (
Place the finished watch case in 3% NaCf) at 40°C x 90°C.
It was immersed for 201' and a half in a warm and humid atmosphere of 50%, and the occurrence of corrosion and discoloration was checked three times.

In the samples of Examples 1 to 32 of the present invention, the finished mobile watch cases in which a hard film mainly composed of chromium carbonitride was formed on the surface by the ion blating method exhibited a color tone very similar to stainless steel, and exhibited a color tone that closely resembled that of stainless steel. In the seawater corrosion resistance test, no corrosion was observed, and in the bending adhesion test, Example 1 of the present invention shown in Table 1
- Two-layer structure shown in 8, Example 9 of the present invention shown in Table 3 -
The adhesion was higher in the order of the three-layer structure shown in Table 16, and the five-layer structure shown in Examples 17 to 32 of the present invention shown in Tables 5 and 7, but the adhesion quality of any structure was lower than that of the watch exterior. It was sufficient as a part. Also, Comparative Example 4 in Table 1 and Table 3,
As shown in Comparative Examples 12.19.26 in Tables 5 and 7, if the total hard coating thickness exceeds 5 μm, the adhesion will be poor and the hard coating will peel off, reducing the adhesion quality. 6
It is more preferable that the hard coating thickness is in the range of 0.15 μrn to 5 μm because the predetermined color tone is maintained at 61 μm and the hardness is also ensured at 11 vloooo or more.

In addition, the film thickness of layer 2 (first layer in Tables 2, 4, 6, and 8) whose main component is metallic chromium is 0 in all cases.
．． 05 μm to 2.0 μrn is preferable.

Mixed layer 4 of metallic chromium and chromium carbonitride (second layer in Table 4), mixed layer 5 of metallic chromium and chromium nitride (second layer in Table 6), mixed layer 8 of metallic chromium and chromium carbide (second layer in Table 6) (second layer in Table 8), mixed layer 7 of chromium nitride and chromium carbonitride (sixth layer)
The film thickness of the chromium carbide and chromium carbonitride mixed layer 10 (the fourth layer in Table 8) is 0.0 in both cases.
5 μm to 0.5 μm is preferable. Layer 6 containing chromium nitride as the main component (third layer in Table 6) and layer 9 containing chromium carbide as main component (third Ji in Table 8) both have a thickness of 0.05 μm to 3.0 μm. preferable.

Furthermore, even if the surface of the 5US304 substrate is subjected to various treatments, such as a striped pattern, a lattice pattern, a matte pattern, a mirror surface, etc., and the hard coating of the present invention is formed thereon, the appearance will not change. The decorative quality of the surface treatment can be expressed in the same manner as in the case where the hard coating is not formed. In particular, the color tone can be made almost the same as the color tone of the base of the 5US304 substrate, and the unique effect of excellent scratch resistance can be added to the SUS and 304 substrates, which have poor scratch resistance.

Furthermore, if the hard coating is subjected to a bolishing process such as puffing, a glossy and highly decorative appearance can be obtained. Further, the surface of the hard coating had sufficient hardness of Hv=1000 or more, and no exposure of the base material was observed in the abrasion resistance test. Nt/CzHz for hard coating color tone
Although it varies slightly depending on the flow rate and gas pressure conditions, most of them have a metallic luster and are very similar to stainless steel, and have an appearance with no difference at all. The method was sufficiently applicable to the following.

However, as shown in Comparative Examples 1.6.13.20 in Table 1, Table 3, Table 5, and Table 7 of Comparative Examples, when the gas pressure becomes extremely high, the hard coating becomes ``=62%, which gives a low brightness and a blackish, lackluster appearance; conversely, when the gas pressure becomes extremely low, as shown in Comparative Example 2.7.14.21, the brightness becomes L''=91%. It was undesirable for use as an exterior part for a watch, as it was too high and the glitter was too noticeable. This is because if the gas pressure is too high, the weight percentage of N and C in the composition ratio of chromium and N and C in the chromium carbonitride hard coating becomes extremely high, and the crystalline bond becomes unstable. The film has a very porous structure and easily absorbs light, resulting in a low L value and a dark tone.On the other hand, if the gas pressure is extremely low, the weight percentage of chromium in the composition ratio of chromium carbonitride decreases. This results in an extremely large amount of chromium, resulting in the shiny appearance characteristic of vapor-deposited metallic chromium.

From the above, the L1 value is more preferably selected in the range of 65%≦L*≦90%.

Furthermore, as shown in Comparative Example 3.8.15.22, the reaction gas was
If only two gases are used, the resulting film will have a strong bluish color characteristic of CrN, resulting in a color that is outside the objective range of the present invention.
In addition, as shown in Comparative Example 4.9.16.23, the reaction gas was
, If only N2 gas is used, the resulting film will be CrC and will have a strong reddish color, which is not preferable. From the above, a * b 1
For =, the ranges of -3≦a*≦5 and -5≦b0≦10 are more preferably selected.

The color tones of the hard coatings in Examples 1 to 32 of the present invention shown in Tables 1 to 8 were determined by ion blating treatment with the flow rate ratio of N Z / Ct Ht, gas pressure, chromium evaporation amount, and treatment time constant. By doing this, the color tone can be easily controlled, and when we sampled products from ion blating that had been processed 10 times under the same conditions and compared them using a color difference meter and visually, we could not recognize any difference. It was confirmed that this manufacturing method has high repeatability for color tones.

The technology of the present invention is applicable not only to exterior parts for watches, but also to all decorative items such as eyeglass frames, lighter cases, decorative bands, buckles, tambins, rings, spoons, and forks.

〔Effect of the invention〕

As mentioned above, the method of polishing the stainless steel material itself and the conventional method of wet-plating brass, nickel silver, etc. with palladium, rhodium, silver, etc., have a soft surface hardness and will not be scratched by long-term use. occurs significantly,
However, according to the present invention, a layer (lower layer) mainly composed of metallic chromium is formed on the surface of the substrate of the decorative member, and a layer (lower layer) mainly composed of chromium carbonitride is formed on the layer (lower layer) mainly composed of chromium carbonitride. By forming a hard coating (upper layer), there is no difference in color tone from conventional stainless steel materials in terms of appearance.
Moreover, it has the effect of providing a decorative member that maintains its original appearance with almost no scratches even after being carried for a long period of time, and has excellent abrasion resistance, adhesion, and corrosion resistance.

4...Mixed layer of metallic chromium and chromium carbonitride 5...Mixed layer of metallic chromium and chromium nitride 6...Layer mainly composed of chromium nitride 7...Mixed layer of chromium nitride and chromium carbonitride 8...Mixed layer of metallic chromium and chromium carbide 9...Layer mainly composed of chromium carbide 10...Mixed layer of chromium carbide and chromium carbonitride Applicant: Seiko Epson Corporation

[Brief explanation of the drawing]

FIGS. 1 to 4 are cross-sectional views of watch cases made in accordance with embodiments of the present invention. l...5US304 substrate (decorative member) 2...Layer containing metallic chromium as the main component (lower layer) 3...Layer containing chromium carbonitride as the main component (upper layer) ψ shout

Claims (5)

[Claims] (1) In a decorative member on which a hard coating is formed, the hard coating includes at least a lower layer mainly composed of metallic chromium and an upper layer formed on the lower layer mainly composed of chromium carbonitride. A decorative member comprising: (2) a lower layer in which the hard coating mainly contains metallic chromium;
2. The decorative member according to claim 1, comprising a three-layer structure including an intermediate layer made of a mixture of metal chromium and chromium carbonitride and an upper layer mainly composed of chromium carbonitride. (3) a lower layer in which the hard coating mainly contains metallic chromium;
The second layer is a mixed layer of metallic chromium and chromium nitride, the third layer is mainly composed of chromium nitride, the fourth layer is a mixed layer of chromium nitride and chromium carbonitride, and the main component is chromium carbonitride. The decorative member according to claim 1, characterized in that it has a five-layer structure with an upper layer. (4) a lower layer in which the hard coating mainly contains metallic chromium;
The second layer is a mixed layer of metallic chromium and chromium carbide, the third layer is mainly composed of chromium carbide, the fourth layer is a mixed layer of chromium carbide and chromium carbonitride, and the main component is chromium carbonitride. The decorative member according to claim 1, characterized in that it has a five-layer structure with an upper layer of. (5) The thickness of the upper layer mainly composed of chromium carbonitride is 0
．． When the surface of the chromium carbonitride is 15 μm to 3.0 μm, it is defined in JIS Z8105-2068 (C
IE 1976) In L^*, a^*, b^* color space, L^*, a^*, b^* are each 65%≦L^*≦
90%, -3≦a^*≦5, -5≦b^*≦10, and has a color tone very similar to that of stainless steel. Element.