JPH0718485A - Material formed patina and its production - Google Patents

Abstract

PURPOSE:To produce a material with patina formed in a tightly adhered state. CONSTITUTION:A Cu layer is electrodeposited on a substrate at current density exceeding limiting current density to increase the surface roughness and a Cu layer is electrodeposited on the above Cu layer in one body at current density below limiting current density to prevent the separation of powder from the Cu layer. Since an electrodeposited layer having high roughness and not causing the separation of powder is formed on the surface of the substrate, the adhesion of patina is improved and the resulting material can maintain its fine appearance over a long period of time when used as a shingle, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material in which patina is firmly adhered to each other and a method for producing the same.

[0002]

2. Description of the Related Art A temple is a copper plate that artificially forms a light green patina (a kind of basic copper salt) that naturally occurs on the surface of copper that has been left in the atmosphere for a long time. Used for roofing boards. There are a chemical treatment method and an electrolytic treatment method in this patina artificial forming method. Among them, the chemical treatment method prepares a treatment liquid in which an additive is added to a copper salt and an ammonium salt, immerses a copper plate in this liquid, or sprays this liquid repeatedly on the copper plate, or mixes this liquid with an aqueous resin. It is a method of applying the formed paste to a copper plate to form it. The electrolytic treatment method is a method of electrolyzing a copper plate as an anode in an aqueous solution containing a carbonate, a bicarbonate, an ammonium salt, an oxyacid salt and the like. The chemical treatment method has a drawback that it takes more time to form patina than the electrolytic treatment method.

[0003]

By the way, since such artificially formed patina has poor adhesion, it is easily peeled off from the copper plate, and thus it is difficult to maintain its aesthetic appearance and corrosion resistance for a long period of time. For this reason, a method of applying a resin to protect patina is adopted, but the resin film is not sufficiently improved because it is deteriorated by the ultraviolet rays of sunlight.

[0004]

The present invention has been made as a result of intensive studies in view of such a situation, and an object thereof is to provide a material in which patina is firmly adhered and a manufacturing method thereof. To do. That is, the invention of claim 1 provides the copper layer A on the substrate with a current density exceeding the limiting current density.
Is electrodeposited, and the copper layer B is electrodeposited thereon at a current density not higher than the limiting current density, and patina is formed on the copper layer B.

In the present invention, the copper layer A electrodeposited on the substrate is a layer electrodeposited under the condition where the limiting current density is exceeded,
Easy to pulverize and has a large surface roughness. Then, the copper layer B is integrally electrodeposited on the electrodeposited copper layer A which is easily pulverized at a current density not higher than the limiting current density to fix the powder on the surface of the copper layer A.
In this way, an electrodeposition layer having a large surface roughness and no powder separation is formed on the substrate, and patina is firmly adhered to this electrodeposition layer.

Incidentally, the crystal structure of the copper layer A has a large roughness and a good mutual bondability in the case of a granular shape having a diameter of several microns to several tens of microns. Further, the thickness of the copper layer B is made as thin as possible within the range in which the powder separation of the copper layer A can be prevented,
It is preferable that the effect of the copper layer A having a large surface roughness is not impaired.

A second aspect of the present invention is a method for producing the patina-forming material according to the first aspect of the present invention, which has a constitution in which a Cu ²⁺ ion concentration is 1 to 50 g / liter on a substrate. The copper layer A is electrodeposited in the liquid A at a current density exceeding the limiting current density, and then the Cu ²⁺ ion concentration is 25 on the electrodeposited copper layer A.
The copper layer B is electrodeposited at a current density not higher than the limiting current density in an electrodeposition liquid B of about 150 g / liter, and then the electrodeposited copper layer B
It is characterized by forming an artificial patina on it.

In the method of the present invention, the reason why copper is electrodeposited on the substrate at a current density exceeding the limiting current density in the electrodeposition liquid A containing Cu ²⁺ ions is that the roughness on the substrate is low. This is for forming a copper layer A having a large thickness to improve the adhesion of patina. The reason for limiting the Cu ²⁺ ion concentration of the electrodeposition liquid A to 1 to 50 g / liter is that if the Cu ²⁺ ion concentration is less than 1 g / liter, the consumption of Cu ²⁺ ions is severe and it is difficult to maintain and manage it during operation. To become. On the other hand, if it exceeds 50 g / liter, the limiting current density becomes very large, which requires an excessive amount of equipment such as a rectifier, which is disadvantageous in terms of cost.

The reason why the copper layer B is electrodeposited on the electrodeposited copper layer A in the electrodeposition liquid B containing Cu ²⁺ ions at a current density lower than the limiting current density is that the copper layer A is separated from the powder. This is to prevent The reason for limiting the Cu ²⁺ ion concentration of the electrodeposition liquid B to 25 to 150 g / liter is that the Cu ²⁺ ion concentration is 25 g / liter.
This is because if it is less than 1 liter, the limiting current density is lowered and there is a risk that the copper layer B itself becomes powdery in the concentration management system during operation. On the other hand, if it exceeds 150 g / liter, it becomes difficult to completely dissolve copper.

In the method of the present invention, any metal material capable of electrodepositing copper, such as copper and copper alloy, as well as steel and stainless steel, can be applied to the substrate. Further, the surface of the base material before copper electrodeposition is subjected to usual degreasing and pickling treatment, but it is preferable to roughen the surface by shot blasting or the like before degreasing because the roughness of the electrodeposited copper layer is further improved. Further, heat treatment at a temperature of 150 to 280 ° C after the formation of patina improves the adhesion and adjusts the color tone. In particular, the green-blue color obtained by the electrolytic method has a strong bluish color because it is basically composed of basic copper carbonate, but it is changed to a slightly greenish and preferable color tone by heat treatment. If a clear coat is applied thinly on the patina thus formed, it is possible to prevent the patina powder from falling off during construction. A conventional chemical treatment method or electrolytic treatment method can be applied to the formation of the artificial patina. In particular, the electrolytic treatment method is preferable because it is excellent in productivity.

[0011]

In the present invention, since the copper layer A is electrodeposited on the substrate at a current density exceeding the limiting current density, the copper layer A is electrodeposited in powder or particles to increase the surface roughness. . The powder is easily separated in the copper layer A, but the copper layer B is integrally electrodeposited on the copper layer A at a current density not higher than the limiting current density, so that the powder separation of the copper layer A is prevented. . Therefore, an electrodeposition layer having high roughness and no powder separation is formed on the surface of the base material, and patina is firmly adhered to the base material via the electrodeposition layer. The material of the present invention can be easily manufactured because the conventional techniques of Cu electrodeposition and patina formation can be applied as they are.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples. Example 1 A 0.4 mm thick phosphorous deoxidized copper plate was sequentially subjected to alkaline degreasing and pickling treatment, and then a copper layer A was electrodeposited in an electrodeposition solution A at a current density exceeding a limiting current density. Then, the copper layer B was electrodeposited on the copper layer A in the electrodeposition liquid B at a current density not higher than the limiting current density. A copper sulfate solution was used as the above electrodeposition solution. The Cu ²⁺ ion concentration of the electrodeposition liquid A is in the range of 1 to 50 g / liter, and the Cu ²⁺ ion concentration of the electrodeposition liquid B is 25 to 150 g.
Within the range of / liter. Next, an artificial patina was formed on the electrodeposited copper layer B. The artificial patina was formed by an electrolytic method using a copper plate as an anode. An aqueous solution containing 5 g / liter of ammonium molybdate, 50 g / liter of ammonium carbonate, and 10 g / liter of ammonium sulfate was used as the electrolytic solution. Liquid temperature is 25 ° C, current density is 10 A / dm ² ,
The electrolysis time was 2 minutes.

[0013] except that the Comparative Example 1 electrodeposition solution a Cu ²⁺ ion concentration in A is 0.8 or 60 g / liter, the electrodeposition liquid 20 or 160 g / liter of Cu ²⁺ ion concentration in B is carried out An artificial patina was formed by the same method as in Example 1. Comparative Example 2 An artificial patina was formed by the same method as in Example 1 except that the copper layer B was not electrodeposited. Comparative Example 3 An artificial patina was formed by the same method as in Example 1 except that the copper layer A was not electrodeposited. Comparative Example 4 An artificial patina was formed by the same method as in Example 1 except that the artificial patina was directly formed on the degreased / pickled phosphorus-deoxidized copper plate.

Each of the phosphor-deoxidized copper plates having patina formed in this way was examined for patina adhesion by a bending test and a sliding test. The bending test was carried out by 180 ° bending the phosphor-deoxidized copper 1 having patina formed on one surface as shown in FIG. 1 with the patina forming surface 2 facing outward, and observing the adhered state of patina at the bent portion. As the constraining plate 3 for bending test, a phosphorous deoxidized copper plate having a thickness of 0.4 mm was used. As shown in FIG. 2, the sliding test is performed on the patina-formed surface 3 of the phosphor-deoxidized copper plate 1 having patina formed on one surface.
A 100 g weight 5 having a felt 4 at the lower end was reciprocated on the upper side, and the number of times of sliding until the patina peeled off was measured. The number of times of sliding was counted as one reciprocating twice. The results are shown in Table 1.

[0015]

[Table 1] Copper ion concentration of electrodeposition liquid, unit: g / liter. Unit: A / dm ² .

As is clear from Table 1, the products of the present invention (No.
All of 1 to 5) showed excellent adhesion in a bending test and a sliding test. Also, the patina color tone was good.
On the other hand, in Comparative Examples Nos. 6 to 9, since the copper ion concentration of the electrodeposition liquid was too low or too high, the adhesion of patina was deteriorated. In No. 10, the powder of the copper layer A was separated and the adhesion of patina was reduced. No. 11 has a low roughness of the copper layer B.
In No. 12, the roughness of the base material was small, and thus the adhesion of patina was markedly reduced.

[0017]

[Effect] As described above, the material of the present invention is a material in which a copper layer having a large surface roughness and having no powder separation is electrodeposited on the base material, and patina is formed thereon, so that the adhesion of patina is good. Therefore, it can be used for roofing boards, etc. and can maintain its beautiful appearance for a long time. Moreover, since the conventional techniques of electrodeposition of copper and patina formation can be applied as they are,
Easy to manufacture.

[Brief description of drawings]

FIG. 1 is an explanatory view of a bending test method for evaluating the patina adhesion of the material of the present invention.

FIG. 2 is an explanatory diagram of a sliding test method for evaluating the adhesion of patina of the material of the present invention.

[Explanation of symbols]

 1 Phosphorus deoxidized copper plate with patina formed on one side 2 Patina forming surface 3 Restraint plate for bending test 4 Felt 5 weights

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C25D 11/34 302

Claims (2)

[Claims] 1. A copper layer A is electrodeposited on a base material at a current density exceeding the limiting current density, a copper layer B is electrodeposited on it at a current density not more than the limiting current density, and green-blue is formed thereon. A material that forms a patina characterized by being formed. 2. A Cu ²⁺ ion concentration of 1 to 50 on the substrate.
A copper layer A is electrodeposited in a deposition solution A of g / liter at a current density exceeding a limiting current density, and then C is deposited on the electrodeposited copper layer A.
Electrodeposition solution B having u ²⁺ ion concentration of 25 to 150 g / liter
In which the copper layer B is electrodeposited at a current density not higher than the limiting current density,
Next, a method for producing a material for forming patina, which comprises forming an artificial patina on the electrodeposited copper layer B.