JPH11241154A - Coloring method of copper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coloring method of copper capable of reducing the ununiformity of color tone and stably obtaining a copper base material colored into a fixed color tone. SOLUTION: Copper is colored by charging it into a gaseous hydrogen sulfide atmosphere. Or Copper can be also colored by dipping it into a solution of an alkali metal sulfide in a treating vessel to be colored and then charging it into the gaseous hydrogen sulfide atmosphere to be colored or by dipping it into the solution of the alkali metallic sulfide in the treating vessel to be colored after charging it into the gaseous hydrogen sulfide atmosphere to be colored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coloring copper, and more particularly, to a method for coloring copper useful for a copper material used for a housing member, a decorative metal fitting, or the like.

[0002]

2. Description of the Related Art Conventional copper coloring methods include, for example,
It has been known that a copper plate is immersed in a treatment solution obtained by dissolving an alkali metal salt such as potassium sulfide or sodium polysulfide in water to be colored.
That is, the oxide film and the fats and oils were mechanically removed with an abrasive or the like.

[0003]

However, in such a method for coloring copper, it is difficult to uniformly remove the oxide film, and in addition, it is difficult to form a poorly soluble salt, so that the copper is colored. However, color tone unevenness considerably occurs, and as a result, it is difficult to stably obtain a copper material colored with a constant color tone.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned facts, and has as its object to reduce unevenness in color tone and to stably produce a copper material colored in a constant color tone. An object of the present invention is to provide a method for coloring copper which can be obtained.

[0005]

According to a first aspect of the present invention, there is provided a method for coloring copper, which comprises introducing copper into an atmosphere of hydrogen sulfide gas for coloring.

According to a second aspect of the present invention, there is provided a method for coloring copper.
After coloring copper by immersing it in a treatment tank containing a sulfide solution of an alkali metal, the above copper is put into an atmosphere of hydrogen sulfide gas for coloring.

[0007] The method for coloring copper according to claim 3 of the present invention comprises:
The method is characterized in that, after copper is charged into an atmosphere of hydrogen sulfide gas and colored, the copper is immersed in a treatment tank containing a sulfide solution of an alkali metal to be colored.

[0008] The method for coloring copper according to claim 4 of the present invention is characterized in that:
The concentration of the hydrogen sulfide gas is 1 to 50 vol%.

[0009] The method for coloring copper according to claim 5 of the present invention is characterized in that:
The humidity in the atmosphere of the hydrogen sulfide gas is 20 to 80%.

[0010] The method for coloring copper according to claim 6 of the present invention comprises:
The temperature of the hydrogen sulfide gas in the atmosphere is 15 to 50 ° C.

[0011]

Embodiments of the present invention will be described below in detail.

In the method of coloring copper according to the present invention, copper is charged into an atmosphere of hydrogen sulfide gas for coloring.

The copper used in the present invention is a copper plate, a copper-plated stainless steel plate, or the like. For example, copper whose copper is sandwiched between nylon scourers and whose surface is polished is used. Further, this copper does not have to be polished, and there is no problem even if it is used as it is.

[0014] The atmosphere of the hydrogen sulfide gas is a zone in which the concentration of the hydrogen sulfide gas used for coloring is maintained at a constant level. Coloring can be achieved by introducing copper into the atmosphere.

[0015] The time for coloring by adding copper is as follows.
It can be adjusted freely according to the target color tone. Specifically, if it is a relatively short time, the color becomes yellowish, and with time, it changes to red and blue-purple.When the target color is reached, the coloring process is completed. It is good.

According to the present invention, by adopting such a method, copper is smoothly and uniformly wrapped with hydrogen sulfide gas, and then a sulfide film is uniformly formed around the surface of copper. The uniform formation of the sulfide film completes the coloring by the hydrogen sulfide gas, and as a result, a copper material colored with a constant color tone with less color tone unevenness can be obtained stably. .

That is, as compared with the case where copper is simply immersed and colored in a treatment tank containing an alkali metal sulfide solution, the color tone unevenness is small and the copper material colored with a constant color tone can be stabilized. It can be obtained by.

If the copper is immersed and colored in a treatment tank containing a sulfide solution of an alkali metal and then the above-mentioned copper is charged into an atmosphere of a hydrogen sulfide gas, the copper is alkali metal. Coloring with a sulfide solution and coloring in an atmosphere of hydrogen sulfide gas and a reliable double coloring process can be performed. Copper material can be obtained reliably and stably.

Further, when copper is charged into an atmosphere of hydrogen sulfide gas to be colored, and then the copper is immersed in a treatment tank containing a sulfide solution of an alkali metal to be colored, the copper is alkali metal. Coloring with a sulfide solution and coloring in an atmosphere of hydrogen sulfide gas and a reliable double coloring process can be performed. Copper material can be obtained reliably and stably.

As the sulfide solution of the alkali metal, various ones can be adopted.
Although not particularly limited, for example, a potassium sulfide solution in which potassium sulfide and ammonium chloride are dissolved in water may be used, or an alkali metal such as sodium sulfide and sodium polysulfide may be used alone or in combination with potassium sulfide. The solution may be used in combination.

The copper plate treated in this manner is washed with water or hot water, a car wash brush-like rotating brush is made with a nylon scrubber, and the brush is polished while rotating the rotating brush. After drying, and then finishing by attaching an antioxidant film, a colored copper material can be obtained.

Thereafter, the color tone of the copper material was evaluated for the presence or absence of color tone unevenness, the color tone stabilization time, and the difference from the target color tone.

In particular, when the concentration of the hydrogen sulfide gas is 1 to 5
If it is 0 vol%, the hydrogen sulfide gas of this concentration works effectively, wraps the copper smoothly and uniformly, and then the hydrogen sulfide gas is more reliably colored with the hydrogen sulfide gas. As a result, as a result, the color tone unevenness is reduced more reliably, and a copper material colored with a constant color tone can be obtained more reliably and stably.

If the concentration of the hydrogen sulfide gas is 1 vol.
When the concentration is less than 1%, the concentration of the hydrogen sulfide gas is too low, and the thickness of the formed sulfide film becomes thin. As a result, color tone unevenness easily occurs, and it takes a long time for the coloring step. become. And, the concentration of the hydrogen sulfide gas is
If it exceeds 50% by volume, the concentration of the hydrogen sulfide gas is too high, and the sulfuration is promoted too much, and the thickness of the formed sulfide film is too large. As a result, the dark-dark sulfide film is formed. Becomes difficult to obtain the desired color tone.

If the humidity of the hydrogen sulfide gas in the atmosphere is 20 to 80%, the hydrogen sulfide gas of the humidity in the atmosphere works effectively and smoothly and uniformly reacts with copper. After being wrapped, it is more reliably colored with the same hydrogen sulfide gas, and as a result, the color tone unevenness is more reliably reduced, and the copper material colored with a constant color tone is more reliably stabilized And what you can get.

If the humidity in the atmosphere of the hydrogen sulfide gas is less than 20%, the humidity in the atmosphere of the hydrogen sulfide gas is too low, and it is difficult to color by sulfuration. In addition to this, the thickness of the formed sulfide film tends to vary, and the color tone can be seen to be light and light. If the humidity in the atmosphere of the hydrogen sulfide gas exceeds 80%, the humidity in the atmosphere of the hydrogen sulfide gas is too high, and the sulfide film to be formed is embrittled. Is a different brittle sulfide film.

Further, if the temperature of the hydrogen sulfide gas in the atmosphere is 15 to 50 ° C., the hydrogen sulfide gas at the temperature in this atmosphere works effectively, and the copper sulfide gas is smoothly and uniformly applied to copper. After being wrapped, it is more reliably colored with the same hydrogen sulfide gas, and as a result, the color tone unevenness is more reliably reduced, and the copper material colored with a constant color tone is more reliably stabilized And what you can get.

If the temperature of the hydrogen sulfide gas in the atmosphere is lower than 15 ° C., the temperature of the hydrogen sulfide gas in the atmosphere is too low, and the thickness of the formed sulfide film becomes small. Color tone unevenness is likely to occur. If the temperature of the hydrogen sulfide gas in the atmosphere exceeds 50 ° C., the temperature of the hydrogen sulfide gas in the atmosphere is too high, and the sulfuration is promoted too much. The thickness becomes too thick, resulting in a dark and dark sulfide film, which makes it difficult to obtain a desired color tone.

According to the method for coloring copper of the present invention, copper is charged into an atmosphere of hydrogen sulfide gas to be colored, so that copper is smoothly and uniformly wrapped with hydrogen sulfide gas and then sulfided. The film was uniformly formed around the surface of the copper, and the uniform formation of the sulfide film completed the coloring with the same hydrogen sulfide gas. As a result, there was little color tone unevenness and the color was colored with a constant color tone A copper material can be stably obtained.

[0030]

Embodiments of the present invention will be described below in detail.

(Example 1) A mixture of hydrogen sulfide gas, air and water vapor was used to adjust the concentration of hydrogen sulfide gas to 10 vol.
A coloring gas was prepared so that the humidity in the atmosphere of hydrogen sulfide gas was 40% and the temperature in the atmosphere of hydrogen sulfide gas was 20 ° C.

Next, a copper plate having a width of 10 cm, a length of 20 cm, and a thickness of 1 mm was prepared, the copper plate was sandwiched between nylon scrubbers (trade name: Scotch Bright), the surface thereof was polished, and the copper plate was filled with the coloring gas. This copper plate was put. When the target color tone is obtained visually, remove the copper plate from the coloring zone, wash it with water, make a car wash brush-like rotating brush with a nylon scrubber (product name: Scotch Bright), and rotate the rotating brush. Polishing and drying were performed to obtain copper A. Furthermore, when this copper A was finished by attaching an antioxidant film, a colored copper material was obtained.

Thereafter, the color tone of the copper material was evaluated for the presence or absence of color tone unevenness, the color tone stabilization time, and the difference from the target color tone.

First, the presence or absence of color tone unevenness on the appearance was visually examined. In addition, in the presence or absence of this color unevenness visually, if the obtained copper material exhibits yellow and blue color unevenness, it is determined that there is color unevenness.

Second, the color tone stabilization time was examined.
In order to quantitatively determine the color tone, a spectrocolorimeter (manufactured by Minolta, CM-2002) was used to determine the color tone by the SCE method.
* Value, a * value, b * value were measured. First, the measured L
* Values, a * values, and b * values were set as initial values, and L * values, a * values, and b * values were measured in the same manner every time from this initial measurement. If the difference between the L * value, a * value, and b * value is equal to or greater than the value shown in the following (Equation 1), it is determined that the color tone has become unstable, and until the color tone becomes unstable. Is obtained as a colorable time, that is, a color tone stabilization time.

[0036]

(Equation 1)

Third, the difference from the target color tone was examined. When there is a target color tone, the target target value is set for each of the L * value, a * value, and b * value, and the difference from the target color tone is different from the target value. The smaller the better. That is, L *
If all of the values, a * values, and b * values are equal to or greater than the values shown in (Equation 2) below, it is determined that there is a difference from the target color tone.

[0038]

(Equation 2)

As a result, regarding the presence or absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time is 8
hr or more, and there was no difference from the target color tone.

Example 2 An aqueous solution obtained by mixing 70 g / l of potassium sulfide and 200 g / l of ammonium chloride was set at a temperature of 20 ° C. to form a potassium sulfide solution.

This potassium sulfide solution is put into a processing tank,
A copper plate whose surface is polished by sandwiching it between the same potassium sulfide solution with a nylon scourer (trade name: Scotch Bright) is immersed for 20 seconds, and then, while washing with water, a car wash brush-like rotating brush with a nylon scourer (trade name: Scotch Bright) , Polishing while rotating the rotating brush,
After drying, copper B was obtained.

A colored copper material was obtained in the same manner as in Example 1 except that the copper B was used in place of the copper plate whose surface was polished in Example 1.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time was 7 hours, and there was no difference from the target color tone.

(Example 3) Copper A similar to that in Example 1 was immersed in the potassium sulfide solution used in Example 2 for 20 seconds.
Then, while washing with water, a rotating brush in the form of a car wash brush was made with a nylon scrubber (trade name: Scotch Bright), polished while rotating the rotating brush, and dried to obtain copper C. Further, when this copper C was finished by attaching an antioxidant film, a colored copper material was obtained.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time was 6 hr, and there was no difference from the target color tone.

(Example 4) The hydrogen sulfide gas concentration was set to 40 vol.
A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 1 except that the amount was 1%.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. Further, the color tone stabilization time is 8 hours or more, and the difference from the target color tone is
There was nothing.

(Example 5) Except that the humidity was set to 60%,
In the same manner as in Example 1, a copper material having a copper sulfide film formed thereon was obtained.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. Further, the color tone stabilization time is 8 hours or more, and the difference from the target color tone is
There was nothing.

(Example 6) Except that the temperature was set to 40 ° C,
In the same manner as in Example 1, a copper material having a copper sulfide film formed thereon was obtained.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. Further, the color tone stabilization time is 8 hours or more, and the difference from the target color tone is
There was nothing.

(Embodiment 7) The hydrogen sulfide gas concentration was set to 40 vol.
A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 2 except that the amount was 1%.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time was 7 hours, and there was no difference from the target color tone.

(Embodiment 8) The hydrogen sulfide gas concentration was set to 40 vol.
A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 3 except that the amount was 1%.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time was 7 hours, and there was no difference from the target color tone.

(Embodiment 9) The hydrogen sulfide gas concentration was set to 0.5 v
A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 1 except that the content was changed to ol%.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence or absence of color tone unevenness, color tone unevenness was slightly present. The color tone stabilization time is 6 hours, and the difference from the target color tone is as follows.
There were some things.

Example 10 The hydrogen sulfide gas concentration was set to 80 V
A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 1 except that the content was changed to ol%.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. Further, the color tone stabilization time is 8 hours or more, and the difference from the target color tone is
There were some things.

Example 11 A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 1 except that the humidity was changed to 10%.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence or absence of color tone unevenness, color tone unevenness was slightly present. The color tone stabilization time is 7 hours, and the difference from the target color tone is as follows.
There were some things.

Example 12 A copper material having a copper sulfide film was obtained in the same manner as in Example 1 except that the humidity was changed to 90%. In addition, the film quality of this copper sulfide film was slightly brittle.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time was 8 hours, and there was a slight difference from the target color tone.

(Example 13) Except that the temperature was 5 ° C,
In the same manner as in Example 1, a copper material having a copper sulfide film formed thereon was obtained.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence or absence of color tone unevenness, color tone unevenness was slightly present. The color tone stabilization time is 6 hours, and the difference from the target color tone is as follows.
There were some things.

Example 14 A copper material having a copper sulfide film formed thereon was obtained in the same manner as in Example 1 except that the temperature was changed to 70 ° C.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence / absence of color tone unevenness, there was no color tone unevenness. The color tone stabilization time was 8 hours, and there was a slight difference from the target color tone.

Comparative Example 1 A copper material having a copper sulfide film was obtained in the same manner as in Example 1 except that the plasma treatment as in Example 1 was not performed.

Next, the color tone of this copper material was evaluated in the same manner as in Example 1. As a result, regarding the presence or absence of the color tone unevenness, the color tone unevenness was considerable. Further, the color tone stabilization time was 3 hours, and the difference from the target color tone was considerable.

Table 1 below shows Examples 1 to 14 and Comparative Example 1.
The processing order and the processing contents of the copper coloring method in the above are summarized. The treatment with the liquids shown in the treatment order 1 and the treatment order 3 in the items in Table 1 means that copper is immersed in a treatment tank containing a potassium sulfide solution to be colored. "Available" indicates that the treatment with the same solution was performed. Further, the gas treatment shown in the treatment order 2 in the items in Table 1 indicates that copper is charged into an atmosphere of hydrogen sulfide gas for coloring, and the H ₂ S concentration and Is the concentration of the hydrogen sulfide gas, the humidity is the humidity in the hydrogen sulfide gas atmosphere, and the temperature is the temperature in the hydrogen sulfide gas atmosphere.

Table 2 below summarizes the results of Examples 1 to 14 and Comparative Example 1 for the presence or absence of color tone unevenness, the color tone stabilization time, and the difference from the target color tone.

[0072]

[Table 1]

[0073]

[Table 2]

Considering Examples 1 to 14 and Comparative Example 1 together with the above while looking at Tables 1 and 2 above, the results of Examples 1 to 14 show that there is no color tone unevenness. ,
Comparative Example 1 Both color tone stabilization time and difference from target color tone
Much better than those of Examples 1-1
It can be seen that the sample of No. 4 is superior to that of Comparative Example 1.

From the above, since copper is charged into the atmosphere of the hydrogen sulfide gas for coloring, the copper is smoothly and uniformly wrapped with the hydrogen sulfide gas, and the sulfide film is coated on the surface of the copper. Uniformly formed around the periphery, the uniform formation of this sulfide film completes the coloring with the same hydrogen sulfide gas.As a result, there is little unevenness of the color tone and the copper material colored with a constant color tone is stabilized. It can be said that it can be obtained.

In addition, when one or more of the copper coloring methods of claims 4 to 6 are employed,
After being wrapped smoothly and uniformly, it is more reliably colored with the same hydrogen sulfide gas, and as a result, the color tone unevenness is more reliably reduced, and the copper colored with a constant color tone It can be said that the material can be obtained more reliably and stably.

Further, the coloration of copper with an alkali metal sulfide solution and the coloring in an atmosphere of hydrogen sulfide gas and a reliable double coloring process result in less color unevenness. It can be said that a copper material colored with a certain color tone can be reliably and stably obtained.

[0078]

According to the method for coloring copper according to claim 1 of the present invention, copper is smoothly and uniformly wrapped with hydrogen sulfide gas, and the sulfide film is uniformly formed around the surface of the copper. The uniform formation of this sulfide film completes the coloring by the hydrogen sulfide gas, and as a result, it is possible to obtain a copper material colored with a constant color tone with less color tone unevenness. You can do it.

According to the method for coloring copper according to the second aspect of the present invention, copper undergoes a reliable double coloring step of coloring with a sulfide solution of an alkali metal and coloring in an atmosphere of hydrogen sulfide gas. As a result, the color tone unevenness is reliably reduced, and a copper material colored with a constant color tone can be reliably and stably obtained.

According to the method of coloring copper according to the third aspect of the present invention, copper undergoes a reliable double coloring step of coloring with an alkali metal sulfide solution and coloring in a hydrogen sulfide gas atmosphere. As a result, the color tone unevenness is reliably reduced, and a copper material colored with a constant color tone can be reliably and stably obtained.

According to the method for coloring copper according to claim 4 of the present invention, in addition to the case described in any one of claims 1 to 3, the hydrogen sulfide gas having this concentration works effectively, and After being wrapped smoothly and uniformly, it is more reliably colored with the same hydrogen sulfide gas.
As a result, the color tone unevenness is reduced more reliably, and a copper material colored with a constant color tone can be obtained more reliably and stably.

According to the method for coloring copper according to claim 5 of the present invention, in addition to the case described in any one of claims 1 to 4, the hydrogen sulfide gas having the humidity in this atmosphere works effectively.
After being wrapped smoothly and evenly with copper, it is more reliably colored with the same hydrogen sulfide gas, and as a result, the color tone unevenness is more reliably reduced, and the constant color tone Thus, it is possible to more stably obtain the copper material colored with.

According to the method for coloring copper according to claim 6 of the present invention, in addition to the case described in any one of claims 1 to 5, the hydrogen sulfide gas at the temperature in this atmosphere works effectively.
After being wrapped smoothly and evenly with copper, it is more reliably colored with the same hydrogen sulfide gas, and as a result, the color tone unevenness is more reliably reduced, and the constant color tone Thus, it is possible to more stably obtain the copper material colored with.

Claims (6)

[Claims] 1. A method for coloring copper, which comprises introducing copper into an atmosphere of a hydrogen sulfide gas for coloring. 2. A method of coloring copper, comprising immersing copper in a treatment tank containing a sulfide solution of an alkali metal and coloring the same, and then introducing the copper into an atmosphere of hydrogen sulfide gas to perform coloring. . 3. A method for coloring copper, which comprises introducing copper into an atmosphere of hydrogen sulfide gas for coloring, and then immersing the copper in a treatment tank containing an alkali metal sulfide solution for coloring. . 4. The concentration of the hydrogen sulfide gas is 1 to 50 v
4. The method according to claim 1, wherein the ratio is ol%.
The method for coloring copper according to any one of the above. 5. The humidity in the atmosphere of the hydrogen sulfide gas is:
The method for coloring copper according to any one of claims 1 to 4, wherein the content is 20 to 80%. 6. The temperature of the hydrogen sulfide gas in the atmosphere is:
The method for coloring copper according to claim 1, wherein the temperature is 15 to 50 ° C. 7.