JPS6184393A - Surface treatment - Google Patents

Abstract

PURPOSE:To carry out surface treatment providing a fine color tone and high surface hardness and giving a surface layer which is not stripped by forming an intermediate metallic layer on a base layer of a hard metallic compound formed on a substrate, activating the surface of the metallic layer, and forming a plated surface layer. CONSTITUTION:A base layer 2 of a hard metallic compound such as TiN or TaN is formed on a substrate 1 of stainless steel or the like by physical vapor deposition. An intermediate metallic layer 3 of a pure metal such as Ni, Pd or Pt or an alloy thereof is formed on the base layer 2 by physical vapor deposition to <=500Angstrom thickness. The surface of the metallic layer 3 is activated with an org. acid such as citric acid, and a plated surface layer 4 of gold, a gold alloy, black rhodium, black ruthenium or the like having a desired color tone is formed on the metallic layer 3 by electrochemical plating. By this method, surface treatment providing stable quality can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method for surface treatment that provides a beautiful color tone such as gold or black and has excellent surface hardness.

"Prior art and its problems" Exterior products such as eyeglass frames, watch bands, and accessories have
Since excellent decorative effects are required over a long period of time, there is a need for surface treatments that have excellent color tone, are resistant to scratches, and have good corrosion resistance.

As a surface treatment method that satisfies such conditions, there is, for example, the method disclosed in Japanese Patent Publication No. 59-26664 for Golden Exterior Parts.

In this method, a hard metal compound such as titanium nitride (TLN) or tantalum nitride (TaN'), which has a color similar to gold, is ionized onto a base material for a watch band made of stainless steel or the like. This is a method in which a base layer is formed by coating by a brating method, and a surface layer is formed by coating gold or a gold alloy on this base layer by an ion blating method or an electrochemical plating method to form a beautiful color tone.

However, in the method of forming the surface layer by ion blasting, only 20 to 30% of the gold/gold alloy is actually coated and becomes the surface layer, and the remaining 70 to 80% is due to the Tt in the device. Since it becomes a layered compound with metal compounds such as N and becomes unrecoverable, there is a problem in that expensive materials such as gold are often wasted. Moreover, in the ion blating method, it is difficult to control the color tone which changes under delicate conditions, and the color tone varies widely, so there is a problem that sufficient quality control cannot be performed.

In addition, in the method of forming the surface layer by electrochemical plating, the base layer made of a metal compound such as TLN is hard and dense, so the low energy applied by electrochemical plating is not suitable for forming the surface layer. It is not possible to diffuse metal atoms such as into the base layer. For this reason, even if the formed surface layer is subjected to heat treatment, etc., sufficient adhesion strength between the surface layer and the base layer cannot be obtained, and the surface layer made of gold, gold alloy, etc. tends to peel off over time. There was a problem.

"Purpose of the Invention" This invention was made in view of the above circumstances. It is an object of the present invention to provide a surface treatment method capable of forming a surface treatment without wasting materials and with less variation in color tone.

"One Means to Solve the Problems" This invention involves forming a base layer made of a hard metal compound on a base material by physical vapor deposition, and depositing a 500 Å thick layer made of pure metal or metal alloy on this base layer. The above problems are solved by forming the following diffusion metal layer by physical vapor deposition, activating this diffusion metal layer with an organic acid, and performing electrochemical plating to form a surface layer on the diffusion metal layer. The aim is to

``Function'' In the surface treatment method of the present invention, ■ Since the diffusion metal layer on the base layer made of a hard metal compound is formed by physical vapor deposition, the metal atoms forming the diffusion metal layer have high energy. It is struck by the base layer, diffuses and penetrates into the base layer. This allows the diffusion metal layer to adhere strongly to the base layer.

■ Furthermore, since the diffusion metal layer is formed of a pure metal or metal alloy that is easily susceptible to diffusion and penetration, the metal that forms the surface layer can diffuse and penetrate into the diffusion metal layer even with the low energy provided by electrochemical plating. I can go. Therefore, even by electrochemical plating, the surface layer is formed in strong adhesion to the diffusion metal layer.

As described above, in the surface treatment method of the present invention, a pure metal or a pure metal that easily undergoes diffusion and penetration is used between the base layer and the surface layer using a physical vapor deposition method that can give high energy to metal atoms. Since the diffusion metal layer made of a metal alloy is formed, the surface layer is strongly adhered to the base layer via the diffusion metal layer, and the surface layer becomes difficult to peel off.

Further, in the surface treatment method of the present invention, since the diffusion metal layer is formed as thin as 500 Å or less, the diffusion metal layer becomes an almost transparent layer. Therefore, the metal/metal alloy that forms the diffusion metal layer can be selected without considering the color balance with the surface layer, so the diffusion metal layer formed by physical vapor deposition, which has poor film formation efficiency, can be ,nickel(
By using an inexpensive metallic material such as Nj), it is possible to reduce the surface treatment cost.

However, when the diffusion metal layer is formed of an inexpensive but easily reactive metal such as N1, this layer is thin, so the activation process when forming the surface layer by electrochemical plating is not performed as usual. If eutectic was used, there was a big problem that the diffusion metal layer would be corroded and disappear. Therefore, in the surface treatment method of this invention, the activation step is performed using an organic acid, thereby eliminating the fear of the above-mentioned loss of the diffused metal layer. A high-quality surface layer that is resistant to peeling can be formed.

"Example" Hereinafter, the present invention will be described in detail with reference to Examples.

The dimensions shown in the figures show the cross section of the surface treated layer obtained by the surface treatment method of the present invention. In this surface treatment layer, a base layer 2 is first formed on the surface of a base material 1, and a diffusion metal layer 3 and a surface layer 4 are sequentially formed on this base layer 2.

The base material 1 is made of various metals such as stainless steel, titanium, brass, or aluminum, alloys of these metals, or non-metals, and is formed into a desired shape such as an eyeglass frame, a watch frame, a watch band, etc. That's what happens. To perform surface treatment on this base material 1, first, the base material 1 is cleaned with a solvent to remove oils and fats, and then
Degrease with alkaline and then dry using Freonsolve.

Next, in the surface treatment method of the present invention, a base layer 2 is formed on the substrate 1. The base layer 2 is a layer made of a hard metal compound, and is suitably formed of a hard metal compound having a color tone similar to that of the surface treatment layer described below and high surface hardness. Examples of such hard metal compounds include:
For example, titanium nitride (TLN) has a color similar to gold.
), tantalum nitride (TaN), black tantalum carbide (TaC), titanium carbide (TLC), chromium carbide (C
r3C2, Cr7C3, Cr23C8), etc. In order to form the base layer 2 from these hard metal compounds, physical vapor deposition methods such as ion blasting method, sputtering method, and vacuum evaporation method are used.

The diffusion metal layer 3 on the base layer 2 is formed by coating the base layer 20 with a pure metal or a metal alloy by physical vapor deposition. This diffusion metal layer 3 improves the adhesion between the base layer 2 and the surface layer 4 described later, and the thickness of this layer 3 is set to be 500 Å or less, more preferably 70 Å or less. If the thickness of this diffusion metal layer 3 exceeds 500 layers, the transparency of the layer 3 will be lost, and if the surface layer 4 (described later) is damaged, the color of this layer 3 will be exposed and the damage to the surface layer 4 will be noticeable. This is both undesirable and uneconomical. It is more preferable that the thickness of this layer 3 is 70 Å or less, since the layer 3 has good transparency.

Further, when the thickness of this diffusion metal layer 3 is 50 Å or less,
It is difficult to form this layer 3 over the entire base material 1, and the adhesion strength of the surface layer 4 becomes uneven, which is not preferable.

Examples of pure metals and metal alloys forming this diffusion metal layer 3 include nickel (NL), palladium (Pd), and platinum (
Pt), iridium (Ir), gold (Au), silver (Ag>
, copper (Cu), rhodium (Rh), indium (In)
Examples include various metals such as, and alloys thereof. Among these, nitrogen is particularly preferably used because it is widely used in general surface treatments, is easy to handle, and is inexpensive.

This diffusion metal layer 3 is formed by a physical vapor deposition method such as an ion blasting method similarly to the base layer 2, but
It is preferable to use the same method as that used to form the base layer 2, since the base B2 and the diffusion metal layer 3 can be sequentially formed in the same apparatus.

A surface layer 4 is formed on the diffusion metal layer 3 thus formed by electrochemical plating.

To form the surface layer 4, as a pretreatment, the base material 1 on which the diffusion metal layer 3 is formed is first degreased using an acidic degreaser, and then activated.

The activation treatment is performed using an organic acid that has poor reactivity with metals such as NL forming the diffused metal H3.

Organic acids are also preferable in that when the base layer 2 is formed of TLN or the like, hydrogen ions (H+) that react with a small amount of carbon eutectoided in the base layer 2 are less likely to be generated.

Examples of organic acids suitably used here include carboxylic acids such as citric acid, acetic acid, oxalic acid, and malic acid;
Examples include sulfonic acids such as sulfamic acid. Among them, citric acid is particularly preferred because it is easy to handle.

After this pretreatment, a surface layer 4 is formed on the diffusion metal layer 3.

Various metals and the like can be used to form the surface layer 4. For example, if the desired color tone is gold, gold or a gold alloy is used. Furthermore, when the desired color tone is black, black rhodium, black ruthenium, etc. are used. The thickness of this surface layer 4 is determined so that the surface layer 4 has a desired color tone and appearance, but if the base layer 2 is formed in a color tone similar to this surface layer 4, the surface layer A desired color tone can be obtained even if the color is thin. When the base layer 2 is formed in a similar color, the thickness of the surface layer 4 is usually 0.1 μm.
It is formed to about 10 μm.

"Example" Surface treatment was performed according to the method of the present invention, and tests such as adhesion were conducted to confirm the effects of the present invention. The experiment was conducted by using a stainless steel watch band as the base material 1 and plating it with gold.

First, the polished watch band was washed with a solvent to remove oils and fats, and then washed with alkaline IB2 oil, washed with Freonsolve, and dried.

Next, this watch band was set on a substrate of an ion blating device, and first a base layer 2 and then a diffusion metal layer 3 were formed.

The base layer 2 was formed by the following procedure according to a conventional method. First, ion bombardment is performed by injecting argon (Ar) into an ion blating device (hereinafter abbreviated as PVD device), and then the inside of the PVI device is placed in a high vacuum (10' to 10
-7 Torr > was evacuated and a voltage of several hundred volts was applied to the substrate to cause ionized titanium (Th > to adhere to the watch band. The titanium (Th) adhered strongly to the watch band and a uniform TL film was obtained. After that, the substrate voltage is lowered, nitrogen gas (N2) is introduced into the PVD equipment, and the pressure inside the PVD equipment is increased to approximately 10' Torr to cause the ionized TL to react with N2, resulting in a material similar to gold. Titanium nitride (
TtN) was attached to the watch band. This was carried out for a predetermined period of time to form a base layer 2 having a thickness of 1 ttm to 2 μm.

Next, Ar was introduced into the PVD equipment and the pressure was increased to 1Q-”1
Sputter cleaning was performed at a substrate voltage of several hundred volts. Thereafter, the pressure inside the PVD apparatus was evacuated to 10-' to 10-' Torr, and the substrate voltage was slightly lowered to allow ionized nickel (N-Si) to adhere to the watch band. This was carried out for a predetermined period of time to form a diffusion metal layer 3 having a thickness of 50 to 70 layers.

Next, when the diffusion metal layer 3 is formed as described above, h
A surface layer 4 made of gold was formed at 22 on one band by electrochemical plating. The treatment steps and conditions are shown in the table below.

The thickness of the formed surface layer 4 was about 0.3 μm, and the obtained product had a beautiful golden color.

The watch bands surface-treated in this manner were subjected to various tests. Next, the content of the test and its results will be described.

a8 Artificial sweat complete collapse test An artificial juice solution having the following composition was kept at 40°C, and a watch band was immersed in it.

Sodium chloride 9.9o/J Sodium sulfide 0.8(]/J Urea 1.7a/,i Aqueous ammonia 0.18o/J Lactic acid 1.1!]/Jl
Sugar blocker 0.220/J remaining pure water After 24 hours, the watch band was removed and its appearance was observed, and there was no abnormality at all. In addition, I tried attaching cellophane tape to this item and peeling it off rapidly, but the surface layer made of gold alloy 4
No peeling occurred.

b. Bending test Each piece obtained by disassembling the above watch band was bent at 60° to 90° using a vise and the appearance was observed.

All the pieces were tested, but no abnormalities such as cracks were observed in the appearance.Also, after applying cellophane tape to the bent portion, the cellophane tape was rapidly peeled off, but no peeling of the surface layer 4 occurred. It did not occur.

C1 salt water test The watch band was immersed in a 3% NaCJ solution at room temperature.

After 48 hours, the watch band was taken out and observed for the presence or absence of rust, but no rust was found.

d. Wear test A wear test was conducted on the watch band using an abrasion tester.

The test conditions were a load of 500 r+ and a wear count of 15,000 times.

When observing the appearance of the watch band after the test, it was found that the surface layer 4
However, since the color tone of the TL forming the base layer 2 is the same as the color tone of the gold alloy forming the surface layer 4, and the diffusion metal layer 3 is thin and transparent, the surface layer 4 is hardly damaged. It wasn't noticeable.

Furthermore, when a titanium eyeglass frame was subjected to the same surface treatment and subjected to the above test, good results were obtained similar to the stainless steel watch band.

"Effects of the Invention" As explained above, the surface treatment method of the present invention involves forming a base layer made of a hard metal compound on a base material by physical vapor deposition, and then depositing a pure metal or metal alloy on this base layer. A diffusion metal layer with a thickness of 500 Å or less is formed by physical vapor deposition,
This method activates this diffusion metal layer with an organic acid and performs electrochemical plating to form a surface layer on the diffusion metal layer.
On the base layer made of C, CCr23C, etc., a surface layer made of gold or gold alloy with a beautiful golden color, black rhodium, black ruthenium, etc. with a beautiful black color, and which adheres strongly to the base layer, is electrochemically applied. It can be formed by a plating method. Therefore, according to this surface treatment method, the surface treatment has a beautiful color tone, high surface hardness, and maintains good appearance quality for a long time without problems such as peeling of the surface layer, without wasting materials. It can be formed without any

Furthermore, since the diffusion metal layer is formed thin, the diffusion metal layer becomes transparent. As a result, the diffusion metal layer can be formed of various metals without considering the color tone of the surface layer.

Therefore, the surface treatment cost can be significantly reduced by forming this diffusion metal layer, which is formed by the physical vapor deposition method, which is inefficient in film formation and wastes a lot of material, with an inexpensive metal such as NL.

Moreover, when a surface layer is formed on such a thin diffusion metal layer by electrochemical plating, activation is performed using an organic acid, so the thin diffusion metal layer may be eroded and lost during the activation process. There is no danger.

Therefore, the surface layer reliably adheres to the base layer via the diffusion metal layer, and according to the method of the present invention, surface treatment with stable quality can be performed. Moreover, since the surface layer is formed by electrochemical plating, the resulting product has little variation in color tone, and this surface treatment method can also reduce the effort required for quality control.

In addition, if the base layer is made of a metal compound with high surface hardness and a color tone similar to that of the surface layer, even if the surface layer is scratched, the base layer will not be damaged; The color tone of the base layer does not stand out, and the resulting product can maintain good appearance quality over the long term.

[Brief explanation of the drawing]

The figure is a cross-sectional view showing the surface condition of a base material treated by the surface treatment method of the present invention. 1...Base material, 2...Base layer, 3...
... Diffusion metal layer, 4 ... Surface layer. Applicant: Mitsuru Iwasaki, Male Procedure Neho (self-motivated) 1. Display of the case 1982 Patent Application No. 204660 2, Name of the invention Surface treatment method 3, Person making the amendment Relationship to the case Patent applicant Mitsuru Iwasaki 4, Agent 2-1-5 Yaesu, Chuo-ku, Tokyo ``Claims,'' ``Detailed Description of the Invention,'' and ``Brief Description of the Drawings'' columns of the specification. (1) Amend the scope of claims as shown in the attached sheet. (2) Specification page 4, line 5, page 4, lines 5-6, page 4, line 7, page 4, lines 11-12, page 4, line 15
line, page 4, line 17, page 4, line 20, page 5, line 2, page 5, line 8, page 5, lines 8-9, page 5, line 11 - line 12, page 5, line 13, page 5, line 14, page 5, line 17, page 5, line 20, page 6, line 4
line, page 6, line 7, page 6, line 17, page 8, line 1
line, page 8, line 3, page 8, line 7, page 8, line 13
line, page 8, line 17, page 9, line 12, page 9, lines 14-15, page 9, line 17, page 10, line 7, page 11, line 10 line, page 12, line 11, page 12, line 13, page 15, line 9, page 15, lines 19-20
line, page 15, line 20, page 16, lines 1-2, page 16, line 13, page 16, lines 13-14, line 16
page 14, line 16, page 16, line 18, page 17, line 1,
The words "diffusion metal layer" on the 7th line of page 10, the 5th line of page 17, and the 2nd line of page 18 are replaced by "intermediate metal layer".
Correct. (3) On page 4, line 5, before the words "physical vapor deposition",
Add [the same physical vapor deposition method used to form the above base layer]. (4) In the 12th line of page 4, in front of "physical vapor deposition", add "same as the physical vapor deposition method used to form the base layer". (5) Page 4, lines 13 to 15 [Diffusion metal layer...bites in]. ] should be corrected as follows. “At the interface between the base layer and the intermediate metal layer, the metal atoms forming the intermediate metal layer and the hard metal forming the base layer become mixed,” (6) [Metal Atoms...can be done] [same as the physical vapor deposition method used to form the base layer]
Correct. (7) On the second line of page 8, in front of ``Physical Vapor Deposition Method'', it says ``
The same method as the physical vapor deposition method used to form the above base is added. (8) 1st diffusion metal layer on page 9, lines 6 to 11...
・Delicious. ” is corrected as follows. ``Since this intermediate metal layer 3 is formed by the same physical vapor deposition method used to form the base layer 2, the base layer 2 and the intermediate metal layer 3 can be formed sequentially in the same apparatus. (9) In the 15th line of page 10, add ``because the intermediate metal layer 3 is transparent'' before ``the base layer 2''. (10) "Example" on page 10, line 20 is corrected to "experimental example." (11) On page 12, lines 5 to 9, ``Next, lower the amount slightly'' is corrected to ``Next, ionize nickel (N, ) in the same PVD device.'' (12) Replace “TL” on page 15, line 7 with “TL N
Correct to J. (13) In the 20th line of page 15, in front of the phrase "physical vapor deposition method," add "same as the physical vapor deposition method used to form the base layer." (14) "Good for a long time" in line 10 of page 16 is corrected to "Good for a long time." Claims: A base layer made of a hard metal compound is formed on a substrate by physical vapor deposition, and a metal layer made of a pure metal or a metal alloy with a thickness of 500 Å or less is formed on the base layer. The rainbow metal layer is formed using the same physical vapor deposition method as the physical/cash deposit, and the rainbow metal layer is activated with an organic acid and electrochemically plated to form a surface layer on the rainbow metal layer. surface treatment method. Procedural amendment (own ship)

Claims (1)

[Claims] A base layer made of a hard metal compound is formed on the base material by physical vapor deposition, and a diffusion metal layer made of pure metal or metal alloy with a thickness of 500 Å or less is formed on this base layer by physical vapor deposition. A surface treatment method characterized by activating the layer with an organic acid and performing electrochemical plating to form a surface layer on the diffusion metal layer.