JPH01165798A - Formation of colored coating film on titanium - Google Patents

Abstract

PURPOSE:To easily obtain a colored Ti (alloy) having a multicolored and clear interfacial profile by coating the requisite part on the Ti (alloy) surface with an electrically conductive material, anodizing the titanium, and then removing the conductive material. CONSTITUTION:The requisite part on the Ti (alloy) surface is coated with the conductive material of desired size and shape. Paint, film, sheet, etc., are used as the conductive material, and the material is closely attached to the Ti (alloy) surface by coating, sticking, spraying, etc., in accordance with the characteristics of the respective materials. The Ti (alloy) is then anodized at a voltage corresponding to the desired coloration with the Ti (alloy) as an anode by using an aq. electrolyte such as an aq. phosphoric acid soln., and then the conductive material is removed from the surface of the Ti (alloy). Accordingly, the coated part is not anodized, and a Ti (alloy) product having a clear interfacial profile separated by at least two colors can be obtained. In addition, after the pattern is obtained by the above-mentioned stage, the Ti (alloy) is again anodized at a lower impressed voltage than the preceding stage, and a multicolor patterned Ti (alloy) product can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a colored film on titanium or a titanium alloy material, and particularly to a method for forming a multicolored colored film on the surface of a titanium or titanium alloy material.

[Conventional technology and its problems]

Titanium and titanium alloy materials (hereinafter referred to as titanium materials) are lightweight, high strength, and have excellent heat resistance and corrosion resistance, so they are used not only in electrical and mechanical parts, but also in eyeglass frames and accessories. Demand is increasing in the field of decorative items.

In such fields, coloring is necessary to enhance the sense of luxury and fashion. Conventional methods for coloring titanium materials include atmospheric oxidation treatment, chemical conversion treatment,
For example, anodizing treatment is proposed in Japanese Patent Publication No. 57-43157.

However, atmospheric oxidation treatment is difficult to control the color tone because the titanium film grows at the product temperature, and chemical conversion treatment is a chemical treatment using chemicals, so the color tone that can be obtained is limited. There is a fundamental problem. On the other hand, anodic oxidation treatment has the advantage that various color tones can be easily obtained. However, conventional anodizing treatment uses a titanium material as an anode and electrolyzes it using an aqueous electrolytic bath, so only one color tone can be obtained over the entire surface of the titanium material, but it can be colored in multiple colors. There was a problem that it was not possible to do so, and the product value was still not sufficient.

[Means for solving problems]

The present invention was developed through research to solve the above-mentioned problems, and its purpose is to easily form a multicolored colored film with a clear interface on the surface of a titanium material. The purpose is to provide a method.

In order to achieve the above object, the present invention employs a method of coating a required portion of the surface of a titanium material with a conductive material, subjecting it to anodization treatment, and then removing the conductive material.

The present invention will be explained in detail below.

First, the present invention employs anodic oxidation treatment as a coloring method. As a coloring method, it is possible to use the above-mentioned atmospheric oxidation treatment or chemical conversion treatment, but these are not suitable because they each have the disadvantage of lacking flexibility in color tone control and freedom in color tone.

In the present invention, prior to this anodic oxidation treatment, required portions of the surface of the titanium material are coated with a conductive material having a desired size and shape (including figures, symbols, etc.). This conductive material is
It can be any paint, film, sheet, etc., and it can be applied to the titanium material by coating, pasting, spraying, etc. depending on the characteristics of each material.

In terms of efficiency, printing methods such as screen printing are also suitable.

Next, anodic oxidation treatment is performed to obtain a colored film of any desired color tone. The conditions for the anodizing treatment are not particularly limited, and a titanium material may be used as the anode, an aqueous electrolytic bath equivalent to a conventional anodizing bath such as an aqueous phosphoric acid solution may be used, and a predetermined voltage depending on the desired color may be applied.

After this treatment, the conductive material is removed from the surface of the titanium material. The conductive material plays the role of a mask material in the anodizing process, and since the covered portion is not anodized, it is possible to obtain a titanium material product that is colored in at least two colors.

As an anodizing prevention means, it is also possible to use an electrically insulating material such as acrylic resin. However, in this case, the anodic oxidation bath liquid tends to enter the area around the coating of the acrylic resin or the like, resulting in blurring of the outline of the one-colored titanium pattern. Furthermore, the application of the anodic oxidation voltage generates heat on the surface of the titanium material, which tends to cause peeling of the acrylic resin and the like, and thereby cause blurring of the outline of the colored titanium pattern.

In the present invention, since a conductive material is used as the mask material, there is a locally narrow gap between the coating (coating material, patch material, etc.) and the surface of the titanium material, which prevents the anodic oxidation bath solution from penetrating. too,
Because the current density on the surface of the titanium material in that area is low, anodic oxidation does not occur and the outline of the colored titanium pattern does not become blurred. Also 1
The heat generated between the titanium material and the coating due to energization is small, and the coating does not peel off due to this, so the outline of the colored titanium pattern is less likely to blur.

Therefore, the higher the conductivity of the conductive material is, the more appropriate it is, and it is preferable that the specific resistance is at least lXl0"Ω・1 or less. Also, since the anodic oxidation bath is water-soluble, the conductive material has water resistance. It is necessary that the

The above is the basic method of the present invention, but if necessary, after obtaining an arbitrary pattern through the above steps, anodization treatment may be performed again at a lower applied voltage than in both subsequent steps. Thereby, an arbitrary color tone can be formed in the portion masked by the conductive material during both subsequent anodic oxidation treatments. therefore,
By repeating this operation a desired number of times, it is possible to obtain a titanium material with a complex and varied multicolored pattern.

After the above treatment, the metal alkoxide glass may be baked. Metal alkoxide glasses have little change in refractive index and have a low curing temperature of about 120°, so baking can be prevented by anode treatment. Since the oxide film is not damaged, it is possible to obtain a colored titanium material that is multicolored and has excellent durability such as color fastness, weather resistance, and abrasion resistance.

Next, examples of the present invention will be shown.

Example 1 ■ Pure titanium plate (40mmQ
mmwX 1mmt) was immersed for 2 minutes in a mixed aqueous solution of 3% by weight hydrofluoric acid and 7% by weight hydrogen peroxide at 25°C to pickle the surface and use it as a sample.

■, Glass-based conductive paint (specific resistance = IX) on the surface of the above sample
After baking a circular shape with a diameter of 15 mm using IO'Ω・all), anodic oxidation was performed by applying an anodic oxidation voltage of 110 V in a 1% by weight phosphoric acid aqueous solution. When the glass-based conductive paint was then peeled off, a pink colored titanium plate containing uncolored circles with a diameter of 15 mm was obtained.

No color bleeding was observed at the interface between the colored and uncolored parts of this colored titanium plate.

Example 2 Using the colored titanium plate prepared in Example 1, anodization treatment was performed again in a 1% by weight phosphoric acid aqueous solution at an anodization voltage of 2 QV.

As a result, a pink-colored titanium plate with a diameter of 15+a+++ including a blue portion was obtained, and no discoloration of the pink portion or bleeding between the pink and blue interface colors was observed.

Example 3 A conductive rubber sheet (thickness 0°1 m) was placed on the surface of the sample of Example 1.
m, specific resistance: lX1O'Ω・country) disk (diameter 15 mm
) was applied, and then anodization was performed in a 1% by weight phosphoric acid aqueous solution by applying an anodic oxidation voltage of 110 V. Then, when the conductive rubber sheet was peeled off, a pink colored titanium plate having a diameter of 15 I1 m and containing an uncolored portion was obtained.

No color bleeding was observed at the interface between the colored and uncolored parts of this colored titanium plate.

Example 4 Using the colored titanium plate prepared in the third example, anodization treatment was performed again in a 1% by weight phosphoric acid aqueous solution at an anodization voltage of 20V.

As a result, a pink-colored titanium plate with a diameter of 15 m+++ including a blue portion was obtained, and no discoloration of the pink portion or bleeding between the pink and blue interface colors was observed.

Comparative Example Using acrylic resin for the sample of Example 1, the diameter was 15+++.
After coating in a circular shape of m and drying, anodization treatment was performed in a 1% by weight phosphoric acid aqueous solution at an anodic oxidation voltage of 110V. In this case, some peeling of the acrylic resin was observed during the anodizing process.6 When the acrylic resin was peeled off after the anodizing process, the color bleeding at the interface of the old acrylic resin and the area that was peeled off during the anodizing process were observed. Pink coloring was observed.

〔Effect of the invention〕

According to the present invention as described above, an excellent effect can be obtained in that a colored titanium or titanium alloy material having a high-quality and fashionable multicolor appearance and a clear interface contour can be easily manufactured.

Claims (1)

[Claims] A method for forming a colored film on a titanium material, comprising: coating a required portion of the surface of titanium or a titanium alloy material with a conductive material, subjecting it to anodization treatment, and then removing the conductive material.