JPH10259487A - Surface treatment, ornaments and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the staining and flawing of the surfaces of Ti or Ti alloy by adhesion of fingerprints. SOLUTION: The surfaces 11 of external parts 10 of watches composed of the Ti or Ti alloy are subjected to machining, such as mirror finishing, honing, streaking, and transparent protective layers 12 are formed on the machined surfaces by applying and drying of, for example, a glass coating liquid. Excellent flawing resistance and fingerprint adhesion resistance are exhibited by the presence of these transparent protective layers 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface treatment method, a decorative article, and an electronic device.

[0002]

2. Description of the Related Art Stainless steel, brass, nickel silver, and various other metals are used as metal materials for an outer case of a wristwatch. Machines such as mirror polishing, streaking, and honing are used as a surface finish. Process is performed.

[0003] In recent years, attention has been paid to Ti as a metal material constituting an outer case of a wristwatch. This Ti is advantageous in that it is lightweight, has high corrosion resistance and high strength, and is a metal allergy resistant material.

[0004]

However, when Ti is used for an outer case of a wristwatch, there are the following problems.

[0005] As a surface finish of the Ti outer case,
Due to the nature of the Ti material, honing processing (honing finish) is the most common. However, since this honing processing forms minute irregularities on the surface, there is a problem that once a fingerprint or the like adheres to the surface, it cannot be removed.

Ti has a Vickers hardness Hv of 15
0 or less, and has a lower hardness than Hv200 of stainless steel (SUS).

Accordingly, the present invention is to solve these problems, and an object of the present invention is to provide a surface treatment method, a decorative article, and an electronic device which can prevent dirt and scratches caused by adhesion of a fingerprint. Is to do.

[0008]

The present invention, which achieves the above object, is a surface treatment method characterized by forming a transparent protective layer on the surface of Ti or a Ti alloy.

As a result, scratches and dirt can be prevented.

The present invention is also a surface treatment method characterized by mechanically processing Ti or a Ti alloy and forming a transparent protective layer on the surface of the processed surface.

It is preferable that the mechanical processing is any one of honing, streaking, and mirror finishing.

As a result, scratches and stains can be prevented, and the transparent protective layer has high adhesion and excellent durability.

It is preferable that the transparent protective layer is a layer containing a glass component.

With this configuration, a surface having sufficient hardness and excellent scratch resistance can be formed, and dirt and scratches such as adhesion of fingerprints can be prevented at a higher level.

Preferably, the transparent protective layer is formed by applying a glass coating liquid to the surface and then drying the glass coating liquid.

With this configuration, the transparent protective layer can be easily formed, and the adhesiveness of the transparent protective layer is high.

The glass coating solution is preferably used by diluting the stock solution with a diluting solution. Particularly, the formation of the transparent protective layer is diluted at a dilution rate corresponding to the type of the mechanical processing. It is preferable to apply the glass coating liquid and then dry it.

With this configuration, the degree of whitening and gloss can be further improved while maintaining the corrosion resistance, abrasion resistance and scratch resistance of the transparent protective layer high.

The viscosity of the glass coating liquid is preferably 150 cps (25 ° C.) or more.

With this configuration, the abrasion resistance of the transparent protective layer,
Scratch resistance is further improved.

It is preferable that the drying is performed twice or more under different drying conditions.

With this configuration, the film quality and adhesion of the transparent protective layer are improved.

The present invention is also a decorative article characterized in that a transparent protective layer is formed on the surface of Ti or a Ti alloy.

This makes it possible to prevent the surface of the decorative article from being scratched or stained.

The present invention is also a decorative article characterized in that a transparent protective layer is formed on a mechanically processed surface of a metal portion made of Ti or a Ti alloy.

It is preferable that the mechanical processing is any one of honing, streaking, and mirror finishing.

Thus, the surface of the decorative article can be prevented from being scratched or stained, and the transparent protective layer has high adhesion and excellent durability.

Further, it is preferable that the transparent protective layer is a layer containing a glass component.

With this configuration, it is possible to form a surface having sufficient hardness, and it is possible to prevent stains and scratches such as fingerprint adhesion at a higher level.

Further, the thickness of the transparent protective layer is from 0.2 to
It is preferably 15 μm.

According to this configuration, a sufficient protective effect can be obtained, and the transparent protective layer can be formed with few defects and good film quality.

Further, the transparent protective layer preferably has a Vickers hardness (Hv) of 180 to 700.

With this configuration, the abrasion resistance of the transparent protective layer,
Scratch resistance is further improved.

It is preferable that the decorative article is a watch exterior part.

Since watch exterior parts are required to have particularly excellent appearance quality, they are highly useful in applying the present invention in which the above-mentioned effects are obtained.

Further, the present invention is preferably configured as an electronic device having at least a part of the decorative article described above.

Here, the electronic device is preferably a watch.

[0038]

Embodiments of the present invention will be described below. The present embodiment described below is an example in which the present invention is applied to an outer case of a wristwatch (portable watch).

First, the watch exterior case will be described.

The watch exterior case is formed by assembling watch exterior parts such as a body (case main body), a back cover, and a cover glass, and also has a cover glass having an edge (bezel) on an outer periphery. Of these watch exterior parts, for example, at least one of the body and the edge is made of Ti (pure Ti) or T
i alloy, such Ti or T
The present invention is applied to a watch exterior part made of an i-alloy.

The Ti alloy is mainly composed of Ti, and other types of 1
Or it contains two or more metals. As a metal that is alloyed (or intermetallic compound) with Ti,
For example, Al, V, Mo, W, Fe, Co, Cr, C
One or more of u, Ag, Pt, Pd, Zn and the like may be mentioned, but not limited thereto.
The content of such a metal is not particularly limited as long as the characteristics of Ti are not significantly changed.

A watch exterior part of a wristwatch is manufactured using the above-described Ti or Ti alloy as a material by, for example, a press molding method, a casting method, a powder metallurgy method, a lost wax method, a metal injection molding method (MIM), or the like. You. In particular, the exterior component manufactured by the press molding method is appropriately subjected to cutting as necessary.

The surface of such a watch exterior part is subjected to mechanical processing as necessary. The mechanical processing includes, for example, a case where a honing process is performed by spraying fine particles, a case where a streak process is performed, and a case where a mirror surface process is performed by buff polishing, barrel polishing, or the like.

Next, the present invention will be described with reference to FIGS.

Timepiece exterior part 10 made of Ti or Ti alloy
The mechanical processing is performed in the vicinity of the surface of. FIG.
In the mechanical processing, particularly, the appearance of the surface of the watch exterior component subjected to honing processing is conceptually shown. On the surface (processed surface) 11 on which the honing process has been performed, minute irregularities are formed.

Even when the streaking is performed, fine linear irregularities are similarly formed on the surface (processed surface). When the mirror surface processing is performed, the processed surface is a smooth surface and the surface roughness is extremely small.

Next, on this surface (processed surface) 11, FIG.
As shown in (1), a transparent protective layer 12 is formed. Thereby, the decorative article (watch exterior part) of the present invention is completed.

As the transparent protective layer 12, a layer containing a glass component such as a glass coating layer is preferable. As a result, a wetting effect due to the refractive index and the like is exhibited, the appearance can be whitened, and the gloss increases. Also, surface 1
It is also prevented that a fingerprint adheres to 1 and the trace impairs the appearance.

The thickness of the transparent protective layer 12 typified by a glass coating layer is not particularly limited.
The thickness is preferably about 15 to about 15 μm, and more preferably about 0.8 to 5.0 μm. If the thickness of the transparent protective layer 12 is too thick, the internal stress in the transparent protective layer increases, and cracks are likely to occur when subjected to an impact. Is reduced.

The hardness of the transparent protective layer 12 is not particularly limited, but the Vickers hardness (Hv) specified in JIS Z 2244 is preferably about 180 to 700, and more preferably about 300 to 500. . Thereby, excellent wear resistance and scratch resistance can be obtained.

When the surface 11 is a processed surface that has been subjected to honing or streaking, an anchor effect is exerted due to minute irregularities existing on the surface 11, and the adhesion of the transparent protective layer 12 is improved.

When the surface 11 is a mirror-finished surface, oxides and other foreign substances are less present on the surface 11, and as a result, the adhesion of the transparent protective layer 12 is improved.

As described above, the improvement of the adhesion of the transparent protective layer 12 prolongs the life of the transparent protective layer 12. That is, it contributes to improvement in durability.

Next, an example of the surface treatment method of the present invention will be described.

<1> Mechanical Processing Mechanical processing is performed on the Ti or Ti alloy surface of the watch exterior component 10 as necessary. As the type of the mechanical processing, for example, the above-described honing processing, streak processing, and mirror finishing can be given.

Note that this mechanical processing need not always be performed.

<2> Removal of Deposits on Surface The surface 11 (whether or not mechanically processed) of the watch exterior component 10 is removed from the surface 11 of the watch exterior component 10 as necessary, by removing foreign substances such as oxides and dirt attached to the surface. Collectively, "surface deposits"
Work to remove). Thereby, the degree of whitening is increased, higher gloss is obtained, and appearance quality is improved.

Representative examples of the treatment for removing the surface deposits include chemical polishing, electrolytic polishing,
Washing (acid washing, alkali washing, water washing, etc.) can be mentioned, and one or more of these treatments can be appropriately combined.

The removal of the surface deposits does not always have to be performed.

<3> Formation of Transparent Protective Layer As shown in FIG.
The transparent protective layer 12 is formed.

The transparent protective layer 12 can be composed of, for example, a glass coating layer. Hereinafter, an example of the formation method will be described.

A transparent glass coating layer can be formed by applying a glass coating liquid to the surface 11 of the watch exterior component 10 by, for example, a coating method and then drying the glass coating liquid.

The glass coating solution for forming the transparent protective layer 12 is mainly composed of a product formed by heating and dissolving alkali silicate and ultrafine silica (for example, manufactured by Okuno Pharmaceutical Co., Ltd.). Transparent glass coating agent, trade name: CRM coat 100) can be used.

This kind of glass coating liquid (stock solution)
Is 100 parts by weight in terms of solid content of alkali silicate such as sodium silicate and potassium silicate, and the average particle size is 40 μm
5 to 100 parts by weight of ultrafine silica of the following order, preferably 50 to 100 ° C., more preferably 80 to 100
It is produced by dissolving under heating at a temperature of ° C., stirring for about 1 to 2 hours, and dissolving (dispersing) ultrafine silica in an alkali silicate.

Here, at the time of the above-mentioned dissolution, water can be present in an amount of preferably not more than 600 parts by weight with respect to 100 parts by weight of the above-mentioned total solid content, so that dissolution can be carried out easily and promptly. it can.

The transparent and inorganic glass coating solution thus obtained can be used as it is or as diluted with a diluting solution.
It is preferable to use one diluted with a diluent. Thereby, the workability of the application operation of the glass coating liquid is improved, and the film quality of the obtained transparent protective layer, in particular, the hardness and corrosion resistance of the film are improved.

In this case, the dilution ratio of the glass coating liquid is determined by the type of the mechanical processing applied to the watch exterior part,
That is, it is preferable to select a material depending on whether it is honing, streaking, or mirror finishing. This makes it possible to further improve the degree of whitening and gloss while maintaining high corrosion resistance, abrasion resistance, and scratch resistance of the transparent protective layer 12.

The preferred range of the dilution ratio according to the type of mechanical processing is as follows. The viscosity of the applied glass coating liquid also has a preferable range. This viscosity corresponds to the dilution ratio, and is shown below together with the dilution ratio.

Honing The dilution ratio is preferably 85% or less, more preferably about 30 to 70%. For example, by adding water to the stock solution, the dilution ratio is 7
0% (water: coating stock solution (volume ratio) = 70:30)
It can be. The viscosity is 150 cps (25 ° C)
The above is preferable, and about 200 to 500 cps (25 ° C.) is more preferable.

Striping The dilution ratio is preferably 85% or less, more preferably about 30 to 70%. For example, by adding water to the stock solution, the dilution ratio is 7
0% (water: coating stock solution (volume ratio) = 70:30)
It can be. The viscosity is 150 cps (25 ° C)
The above is preferable, and about 200 to 500 cps (25 ° C.) is more preferable.

Mirror finishing The dilution ratio is preferably about 50 to 98%, and 90 to 98%.
The degree is more preferred. For example, water is added to the stock solution, and the dilution ratio is 95% (water: coating stock solution (volume ratio) = 95:
5). The viscosity is 150-400 cp
s (25 ° C.) is preferred, and 150 to 250 cps (25
C)) is more preferable.

If the dilution ratio is too high (the viscosity is too low),
Corrosion resistance, abrasion resistance or scratch resistance of the transparent protective layer obtained by the glass coating may decrease. On the other hand, if the dilution ratio is too low (the viscosity is too high), the degree of whitening or the degree of gloss is reduced, particularly in the case of mirror-finished ones.

When the transparent protective layer is made of a material other than glass such as an organic film, the diluent used for the coating may be water or an organic solvent such as alcohols, benzene or toluene. Can be used, and these organic solvents can be used by mixing with water.

Examples of the method for applying the above glass coating liquid include a dipping method (dipping), a spray method, a roll coater, and brushing.

Next, the glass coating liquid applied to the surface 11 is dried. Although the drying conditions are not particularly limited, the drying is preferably performed at a temperature of room temperature to 250 ° C. for 1 to 20 minutes, and more preferably at a temperature of 150 to 230 ° C. for 5 to 15 minutes.

Further, such drying may be performed twice or more under the same or different drying conditions. In particular, when drying is performed twice or more under different conditions (at least one of the conditions such as a drying method, a drying temperature, and a drying time (drying speed)), the film quality of the transparent protective film 12 (particularly, denseness) , Homogeneity, uniformity of thickness) and adhesion.

Further, the application of the glass coating liquid and the drying thereof may be regarded as one step, and this step may be repeated a plurality of times.

As an example, the glass coating solution diluted to a predetermined dilution rate is sprayed on the front surface 11 of the wristwatch body by a spray gun,
Preliminary drying at 10 ° C. × 10 minutes is performed. Next, the same glass coating liquid is similarly sprayed on the surface 11 on the back side (inner side) of the body, and temporary drying is performed at 150 ° C. for 10 minutes. After that, the drying fan and the exhaust fan are operated with 180
Perform main drying at 10 ° C. × 10 minutes. Thereby, a transparent protective layer made of a glass layer is formed. Such a transparent protective layer is excellent in corrosion resistance, abrasion resistance, scratch resistance, impact resistance, fingerprint adhesion resistance and adhesion.

In order to further enhance the corrosion resistance, abrasion resistance, abrasion resistance and the like of the transparent protective layer, a glass coating liquid (coating liquid) may be applied a plurality of times before the main drying.

Hereinafter, a specific example will be described.

A watch exterior part made of pure Ti as a base metal was manufactured by a press molding method, and then the surface thereof was subjected to honing, streaking, or mirror finishing, respectively.

Further, a molded product obtained by the metal injection molding method (MIM) was sintered to produce a watch exterior part made of pure Ti as a base metal. The mechanical processing was not applied to this watch exterior part.

Next, the watch exterior parts subjected to the honing processing and the streak processing, and the watch exterior parts manufactured by MIM were respectively immersed in an etching treatment solution, and the surfaces were chemically polished. The composition of the etching solution is H
F: 3.5 vol%, HNO ₃ : 32.0 vol%, H
₂ SO ₄ : 51.0 vol%, the balance being water. The temperature of the etching solution was 65 ° C. The immersion time in the etching solution was 25 seconds. After the etching treatment, the substrate was washed with warm water.

The mirror-finished watch exterior part was not subjected to the above-mentioned chemical polishing, and proceeded to the next step.

Next, a transparent protective layer was formed on each watch exterior part as follows.

First, sodium silicate was converted to a solid content of 10%.
0 parts by weight and ultrafine silica 50 having an average particle size of 30 μm.
Parts by weight at 85 ° C., and stirred for about 1 hour.
The ultrafine silica particles were dissolved (dispersed) in an alkali silicate to obtain a stock solution of a glass coating solution.

Next, this glass coating stock solution was diluted with water to prepare a glass coating solution whose dilution ratio and viscosity (25 ° C.) were variously changed as shown in Table 1 below.

Next, each of the glass coating solutions was applied to the surface of each of the watch exterior parts by a spray method, and dried to form a transparent protective layer having a thickness (average value) shown in Table 1.

The drying was performed by temporary drying at 150 ° C. for 10 minutes and main drying at 180 ° C. for 11 minutes.

For each of the obtained watch exterior parts, the appearance quality of the surface on which the transparent protective layer is formed, Vickers hardness (Hv), anti-fingerprint adhesion (the difficulty of adhering fingerprints), abrasion resistance and adhesion of the transparent protective layer Was examined. The results are shown in Tables 1 and 2 below.
Shown in

In the evaluation of the appearance quality and the like in Tables 1 and 2, H is the one subjected to honing processing, S is the one subjected to streaking, M is the one subjected to mirror polishing, and N is the mechanical polishing. Each of which has not been subjected to a specific processing (MIM molded product) is shown.

[0092]

[Table 1]

[0093]

[Table 2]

The appearance quality in Table 1 was evaluated by visual classification and classified into the following five grades.

A: Excellent appearance (very high whiteness and extremely high gloss) B: Good appearance (high whiteness and high gloss) C: Normal appearance (medium and medium gloss) D: Somewhat poor appearance (somewhat whiteness) E: poor appearance (small whiteness and no gloss) Evaluations A and B are those that do not cause any problems when actually commercialized, and evaluation C is, for example, a high quality product. Except for special products that require such special high quality, there is no problem.

The fingerprint adhesion resistance in Table 1 was examined when the mechanical processing was H and M, and the average was evaluated. In this case, the judgment was made based on the degree of the fingerprint when the finger was lightly touched, and the evaluation was performed by classifying into the following four grades.

◎: No fingerprint attached at all ○: Little fingerprint attached △: Some fingerprint attached ×: Fingerprint adhered severely. , S, M and N, and the average was comprehensively evaluated.
Of these, Test 1 showed the result of 15,000 times of abrasion test on cowhide under a pressure of 500 g / cm ² , and Test 2 showed A
1 shows the results of the scratch test performed on the material, Test 3 shows the results of the scratch test performed on the BS steel material, and Test 4 shows the results of the scratch test performed on the stainless steel wire. Each was classified into the following four grades and evaluated.

◎: No scratch at all ○: Hardly scratched Δ: Slight scratched ×: Scratched sharply The adhesion of the transparent protective layer in Table 2 was Then, the adhesive tape was applied, and it was judged by the presence or absence of peeling of the transparent protective layer when the adhesive tape was peeled off.

◎: No peeling of the transparent protective layer at all. ○: Little peeling of the transparent protective layer. Δ: Little peeling of the transparent protective layer. X: Strong peeling of the transparent protective layer. As shown in FIG. 2, in Examples 1 to 7, excellent appearance quality, fingerprint adhesion resistance, and scratch resistance were obtained. In particular, the type of mechanical processing (H, S, M)
It can be seen that by selecting an appropriate dilution ratio according to the above, the degree of whitening and the degree of gloss can be increased, and the appearance quality can be further improved.

In Examples 1 to 7, those subjected to mechanical processing are particularly excellent in the adhesion of the transparent protective layer.

On the other hand, the comparative example in which the transparent protective layer was not formed was inferior in fingerprint adhesion resistance and scratch resistance.

In the present invention, the coating liquid for forming the transparent protective layer is not limited to the one described above, and any composition, temperature, dilution ratio, and viscosity of the coating liquid can be used as long as the transparent protective layer can be formed. The conditions such as the coating method and the like can be arbitrary.

For example, various coating liquids including inorganic aluminum oxide, silicon oxide, water glass and the like can be used.

The transparent protective layer is not limited to an inorganic material, but may be a material (organic film) made of a polymer material such as a hard resin.

Further, the method of forming the transparent protective layer is not limited to the above-mentioned coating method (coating), but may be any of various wet plating, dry plating (eg, vapor deposition, sputtering, ion plating, CVD) and the like. May be.

The formation of the transparent protective layer is preferably carried out usually within 144 hours after the step of removing the surface deposits is completed. If the time exceeds 144 hours, an oxide layer starts to be formed on the surface, and a slight discoloration may start to occur.

Further, the present invention is not limited to the case where almost the entire exterior part of a wristwatch or an exterior case obtained by assembling the same is covered with a transparent protective layer.
A transparent protective layer such as a glass coating layer may be provided on a part of the surface of the outer case or other various decorative articles, or on a plurality of locations on the surface.

For example, if the transparent protective layer is formed while the inside of the watch exterior case is masked, the transparent protective layer is not formed on the inner surface of the watch exterior case. When storing and fixing, the machine body can be accurately positioned, and the constituent material of the transparent protective layer can be prevented from being adversely affected on the machine body.

For example, when snapping the back cover to the body,
If there is a possibility that the swarf of the transparent protective layer on the engaging surface of the trunk or back cover may enter the machine body and hinder the driving of the machine body, causing delay or stoppage, transparent protection is provided on the snap engagement surface of both. By not forming a layer, such inconvenience can be prevented.

The present invention is not limited to the formation of the transparent protective layer on the substrate of Ti or Ti alloy, but the transparent protective layer is formed on the surface of the Ti or Ti alloy layer formed on a predetermined base material. It may be formed.

The present invention can be applied to an outer case or a band of a wristwatch and a finished watch using the same, but is not limited to these, and is applicable to other types of timepieces such as other portable timepieces, table clocks and wall clocks. Can be similarly applied.

Also, other than watches, for example, eyeglass frames, tie pins, cufflinks, lighters or their cases, pens, rings, necklaces, bracelets, brooches, pendants, earrings, earrings, tiaras, jewellery, ornaments, interiors The present invention can also be applied to decorative articles such as products (those having a little decorative property) or accessories.

The present invention is also directed to electronic devices partially provided with the above-described decorative article (at least partially used so as to exhibit a decorative effect). Examples of such electronic devices include electronic watches, mobile phones, pagers, calculators, personal computers, word processors, printers, copiers, cameras, video devices, televisions, audio devices, electronic toys, various measuring devices, and the like. Can be

Furthermore, the present invention is not limited to such decorative articles, accessories, and electronic devices, and can be applied to various Ti or Ti alloy members.

[0115]

As described above, according to the present invention, the following effects can be obtained.

By forming the transparent protective layer, excellent scratch resistance and fingerprint resistance can be obtained. In particular, by forming the transparent protective layer as a layer containing a glass component such as a glass coating layer, the transparent protective layer can be easily formed, and the transparent protective layer has high hardness, excellent corrosion resistance and excellent wear resistance. It can be a layer, and also contributes to improvement in appearance quality.

The above-described excellent effects can be obtained even if mechanical processing such as honing, streaking, or mirror finishing is performed on the surface of Ti or Ti alloy in advance. In this case, the adhesion of the transparent protective layer is further increased, and the durability is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view conceptually showing a surface state in a processing step of an embodiment according to the present invention.

FIG. 2 is an explanatory view conceptually showing a surface state in a processing step of an embodiment according to the present invention.

[Explanation of symbols]

 10 Watch exterior parts 11 Surface 12 Transparent protective film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G04B 37/22 G04B 37/22 N

Claims (18)

[Claims] 1. A surface treatment method comprising forming a transparent protective layer on a surface of Ti or a Ti alloy. 2. A surface treatment method comprising mechanically processing Ti or a Ti alloy and forming a transparent protective layer on the surface of the processed surface. 3. The surface treatment method according to claim 2, wherein the mechanical processing is one of honing, streaking, and mirror finishing. 4. The surface treatment method according to claim 1, wherein the transparent protective layer is a layer containing a glass component. 5. The surface treatment method according to claim 1, wherein the transparent protective layer is formed by applying a glass coating liquid to the surface and then drying the glass coating liquid. 6. The surface treatment method according to claim 5, wherein the glass coating solution is used by diluting a stock solution thereof with a diluent. 7. The method according to claim 2, wherein the formation of the transparent protective layer is performed by applying a glass coating liquid diluted at a dilution rate corresponding to the type of the mechanical processing, and then drying the glass coating liquid. Surface treatment method. 8. The glass coating liquid has a viscosity of 1
The surface treatment method according to claim 7, wherein the surface treatment temperature is 50 cps (25 ° C.) or more. 9. The surface treatment method according to claim 7, wherein the drying is performed twice or more under different drying conditions. 10. A decorative article comprising a transparent protective layer formed on the surface of Ti or a Ti alloy. 11. A decorative article characterized in that a transparent protective layer is formed on a mechanically processed surface of a metal portion made of Ti or a Ti alloy. 12. The honing process, wherein the mechanical process is
12. A line processing or a mirror processing.
Decorative items described in. 13. The decorative article according to claim 10, wherein said transparent protective layer is a layer containing a glass component. 14. The transparent protective layer has a thickness of 0.2 to 1
14. The decorative article according to claim 10, which has a thickness of 5 μm. 15. A Vickers hardness (H) of the transparent protective layer.
The decorative article according to any one of claims 10 to 14, wherein v) is 180 to 700. 16. The decorative article according to claim 10, wherein said decorative article is a watch exterior part. 17. An electronic device comprising at least a part of the decorative article according to claim 10. Description: 18. The electronic device according to claim 17, wherein the electronic device is a watch.
An electronic device according to claim 1.