KR101236165B1 - Environmental friendly three element alloys plating solution and method for treating metal surface using the same - Google Patents

Abstract

The present invention relates to a ternary alloy plating solution and a metal surface treatment method using the same. The present invention provides a ternary alloy plating solution of Cu—Zn—Sn containing copper oxide, zinc oxide, sodium carbonate, and a basic substance. In addition, the present invention is a pre-treatment step of pre-treating the subject; A zinc substitution step of replacing zinc with the pretreated subject using a zinc substitution treatment solution; A copper plating step of plating copper on the zinc-substituted conductor; And a ternary alloy plating step of plating a ternary alloy of Cu—Zn—Sn on the copper-plated subject by using the ternary alloy plating solution.

Description

ENVIRONMENTAL FRIENDLY THREE ELEMENT ALLOYS PLATING SOLUTION AND METHOD FOR TREATING METAL SURFACE USING THE SAME}

The present invention relates to an environmentally friendly ternary alloy plating solution and a metal surface treatment method using the same, and more particularly, to a ternary alloy which is environmentally friendly, does not cause nickel allergy, and obtains a highly reliable metal surface. It relates to a plating solution and a metal surface treatment method using the same.

Metal surface treatment technology is a highly precise technology that enhances the value of metal materials, such as improving the corrosion resistance, abrasion resistance, heat resistance and the like of the metal and improve the color and gloss of the metal surface. Among metal surface treatment techniques, alloy plating is the most preferred. An alloy is obtained by adding one or more of these and other elements to a metal, and there are two main purposes for making an alloy. One is to make use of the characteristics of the base metal and to improve it, and the other is to complement and improve the base metal crystal.

Recently, as skin allergy due to nickel is a problem, the demand for nickel-free (Ni-free) of metal surface treated parts is gradually increasing. Accordingly, in the case of accessories, other plating for nickel-free has been applied.

In the case of mobile phone-related components, ternary alloy plating solutions have been developed in consideration of nickel-free, ease of wastewater treatment, and economical efficiency. Ternary alloys are composed of copper (Cu), zinc (Zn), and tin (Sn), have excellent corrosion resistance under any conditions, low electrical resistance like silver (Ag), and hardness like nickel (Ni) Has a high advantage.

The ternary alloy plating solution of Cu-Zn-Sn does not contain nickel, which can solve the problem of nickel allergy, and it may be environmentally friendly because it does not use lead, which is an environmental target material. However, conventional ternary alloy plating solutions do not sufficiently satisfy reliability such as wear resistance, hardness, corrosion resistance, adhesion of base metals, and the like.

Accordingly, an object of the present invention is to provide an environmentally friendly ternary alloy plating solution and a metal surface treatment method using the same, which are environmentally friendly, overcoming nickel allergy, and having excellent physical properties such as corrosion resistance, abrasion resistance, and adhesiveness to obtain a highly reliable metal surface. There is.

In addition, an object of the present invention is to provide an environmentally friendly ternary alloy plating solution that can improve the reliability while overcoming the barriers of environmental regulation and metal surface treatment using the same.

In order to achieve the above object, the present invention provides a ternary alloy plating solution of Cu-Zn-Sn containing copper oxide, zinc oxide, sodium carbonate and basic materials.

Preferably, the ternary alloy plating solution of the present invention further comprises at least one additive selected from aminoethylsulfonic acid and potassium carbonate. In addition, the basic material is at least one selected from sodium hydroxide and potassium hydroxide.

In addition, the present invention provides a metal surface treatment method comprising a ternary alloy plating step of plating a ternary alloy of Cu-Zn-Sn on a subject using the ternary alloy plating solution.

In addition to this,

A pretreatment step of pretreating the subject;

A zinc substitution step of replacing zinc with the pretreated subject using a zinc substitution treatment solution;

A copper plating step of plating copper on the zinc-substituted conductor; And

It provides a metal surface treatment method comprising a ternary alloy plating step of plating a ternary alloy of Cu-Zn-Sn on the copper-plated conductor using the ternary alloy plating solution.

Preferably, the pretreatment step includes at least one selected from an immersion degreasing step of depositing and degreasing the subject in a degreasing solution and an electrolytic degreasing step of electrolytic degreasing. At this time, the degreasing liquid, it is good to include a surfactant 2 ~ 7ml / L based on 1 liter (L) of the degreasing liquid.

In addition, the zinc substitution step,

A first zinc substitution process of substituting zinc in the pretreated subject using a zinc substitution treatment solution;

A zinc peeling process of peeling zinc of the first zinc-substituted object using a zinc peeling solution; And

It is preferable to include the secondary zinc substitution process of substituting zinc to the said zinc peeled object using a zinc substitution process liquid.

At this time, the zinc replacement treatment liquid, preferably 100 to 150 g / L potassium pyrophosphate based on the total of 1 liter (L) of the treatment liquid, the zinc stripping solution may include hydrofluoric acid and nitric acid.

According to the present invention, it is possible to obtain a highly reliable metal surface by overcoming nickel allergy and being environmentally friendly and excellent in physical properties such as corrosion resistance, abrasion resistance, and adhesion.

FIG. 1 is a photograph of a specimen (magnesium alloy) used as a conductor (base metal) in an embodiment of the present invention.
Figure 2a shows the surface component analysis results and photos before the pretreatment (degreasing) of the specimen used in the embodiment of the present invention.
Figure 2b shows the results of the component analysis and photographs on the surface of the specimen after pretreatment (degreasing) according to an embodiment of the present invention.
Figure 3a shows the results of the component analysis and photographs on the surface of the specimen subjected to the primary zinc substitution (primary zincate) according to an embodiment of the present invention.
Figure 3b is a photograph confirming the surface roughness of the specimen subjected to the first zinc substitution treatment (primary jincate) according to an embodiment of the present invention through a 3-Dimensional Interactive Display.
Figure 4 shows the component analysis results and photographs on the surface of the specimen after zinc peeling according to an embodiment of the present invention.
Figure 5a shows the results of the component analysis and photographs on the surface of the specimen subjected to the secondary zinc substitution (primary zincate) according to an embodiment of the present invention.
Figure 5b is a photograph confirming the surface roughness of the specimen subjected to the second zinc substitution treatment (secondary jincate) according to the embodiment of the present invention through a 3-Dimensional Interactive Display.
6a and 6b is a test report showing the results of the salt spray test of the surface-treated specimen in accordance with an embodiment of the present invention.
7 is a test report showing the results of the acid resistance test of the surface-treated specimen in accordance with an embodiment of the present invention.
8 is a test report showing the wear resistance test results of the surface-treated specimen in accordance with an embodiment of the present invention.
9 is a test report showing the thermal shock test results of the surface-treated specimens according to the embodiment of the present invention.
10A and 10B are test reports showing the results of environmentally harmful evaluation of surface treated specimens according to an embodiment of the present invention.
11 is a photograph of the surface of the specimen surface-treated according to the Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described in detail.

In the present invention, the subject is a base metal to be subjected to surface treatment, that is, a base metal to be surface-treated by plating of the ternary alloy plating solution according to the present invention, which is a semi-finished product, a finished product and a metal material for manufacturing these semi-finished products. Include. In addition, the present invention includes a single metal or alloy, for example, a single metal such as magnesium (Mg), aluminum (Al), iron (Fe) and copper (Cu) or at least one metal selected from these It may be an alloy containing. In addition, in this invention, the to-be-conducted body may be the metal plated on the surface. For example, a plating layer such as chromium (Cr), zinc (Zn) or copper (Cu) may be coated.

The ternary alloy plating solution according to the present invention includes copper oxide (Cu ₂ O), zinc oxide (ZnO), sodium carbonate, and a basic substance. Ternary alloy plating solution according to the present invention may be composed of an aqueous solution containing the above components. Among the above components, sodium carbonate is a sodium salt containing tin, which may use, for example, sodium carbonate represented by the formula Na ₂ O ₆ Sn or Na ₂ SnO ₃ . In addition, the sodium carbonate may be, for example, sodium hydrate tetrahydrate (Na ₂ SnO ₃ 4H ₂ O) or the like as a hydrate. In addition, the basic substance may be one having a 0H group in the molecule, and preferably at least one (one or both) selected from sodium hydroxide (NaOH) and potassium hydroxide (KOH) may be used. More preferably, both sodium hydroxide (NaOH) and potassium hydroxide (KOH) are included.

In addition, the ternary alloy plating solution according to the present invention may further include an additive in addition to the above components. The additive may be used that is commonly used in the art. Preferably, the additive is one or more selected from aminoethylsulfonic acid and potassium carbonate, and more preferably all of them are used. At this time, the aminoethylsulfonic acid imparts glossiness to the ternary alloy plating film, effectively improving the surface property of the film, and the potassium carbonate plays a role as a smoothing agent (leveler) together with the gloss.

In addition, the ternary alloy plating solution according to the present invention has a specific composition content (concentration), based on 1 liter (L) of the plating solution (aqueous solution), 20 to 25 g / L copper oxide, 1.2 to 1.4 g / L zinc oxide, It is preferred to include 65-80 g / L sodium carbonate and 52-70 g / L basic substance. More preferably, 20 to 25 g / L of copper oxide, 1.2 to 1.4 g / L of zinc oxide, 65 to 80 g / L of sodium carbonate, and 52 to basic material, further including an additive, based on 1 liter (L) of the plating liquid 70 g / L, amino ethyl sulfonic acid (first additive) 8-12 ml / L and potassium carbonate (second additive) 8-12 ml / L are preferred. In addition, the basic material includes both sodium hydroxide and potassium hydroxide, the sodium hydroxide is based on a total of 1 liter (L) of the plating solution 40 ~ 50g / L, the potassium hydroxide is contained in 12 ~ 20g / L desirable. According to a more specific embodiment, the ternary alloy plating solution according to the present invention, based on 1 liter (L) of the plating solution, copper oxide 22g / L, zinc oxide 1.3g / L, sodium carbonate 70g / L, sodium hydroxide 45g / L, 15 g / L potassium hydroxide, 10 ml / L aminoethylsulfonic acid (first additive) and 10 ml / L potassium carbonate (second additive).

The ternary alloy plating solution according to the present invention described above is plated on a conductor (base metal) to form a ternary alloy plating layer (film) of Cu—Zn—Sn. For example, it may be plated by an electroplating method. The ternary alloy plating solution according to the present invention is nickel-free and cyan-free plating chemicals containing no nickel (Ni) but also a cyanide compound (CN-). Harmless to In addition, the ternary alloy plating solution according to the present invention has excellent physical properties required in plating products such as corrosion resistance, acid resistance, abrasion resistance, and adhesion, thereby realizing a highly reliable metal surface.

On the other hand, the metal surface treatment method according to the present invention comprises at least a ternary alloy plating step of plating a ternary alloy of Cu-Zn-Sn on the subject using the ternary alloy plating solution of the present invention as described above.

According to a preferred embodiment, the metal surface treatment method according to the present invention comprises the following steps (1) to (4).

(1) pretreatment step of pretreatment of the subject

(2) a zinc substitution step of substituting zinc in the pretreated subject using a zinc substitution treatment solution

(3) Copper plating step of plating copper on the zinc-substituted conductor

(4) a ternary alloy plating step of plating a ternary alloy of Cu—Zn—Sn on a copper-plated conductor using the ternary alloy plating solution of the present invention

Each step will be described as follows.

(1) pretreatment step

First, the subject is pretreated. The pretreatment may be carried out by a method conventionally performed in the art, and the pretreatment may include, for example, a washing process for removing impurities.

The pretreatment preferably includes at least one selected from an immersion degreasing step of depositing and degreasing the subject in a degreasing solution, and an electrolytic degreasing step of subjecting the subject to a degreasing solution. Such deposition and electrolytic degreasing can remove not only impurities but also oil components. In addition, the release agent substance (Si component) and the like can be removed.

The degreasing liquid may include at least one selected from sodium hydroxide (NaOH) and a surfactant. At this time, the degreasing liquid, sodium hydroxide (NaOH) is preferably contained in a concentration (content) of 100g / L or more based on 1 liter (L) of the degreasing liquid. For example, it is preferable to include 100 ~ 150g / L sodium hydroxide (NaOH). As such, when sodium hydroxide (NaOH) is included in the degreasing solution, the oil component of the subject can be effectively removed. In addition, it is good that degreasing liquid contains 2-7 ml / L of surfactants with respect to 1 liter (L) of whole degreasing liquids. In this case, the surfactant may be preferably ethoxylated nonlyphenol. As such, when the degreasing solution contains a surfactant, not only the oil component of the subject but also a release agent material (Si component) can be effectively removed. According to a specific embodiment, the degreasing liquid is sodium hydroxide (NaOH) 100 to 150 g / L, sodium carbonate (Na ₂ CO ₃ ) 80 to 150 g / L and surfactant 2 to 7 ml based on 1 liter (L) of degreasing solution. It may be composed of an aqueous solution containing / L.

The degreasing step, that is, the deposition degreasing step and the electrolytic degreasing step is not particularly limited. For example, the immersion degreasing process may be carried out by immersing the subject in the degreasing solution as described above, and then maintaining the same at a temperature of 50˜80 ° C. for 5 to 30 minutes. In addition, the electrolytic degreasing process may be performed by depositing a subject in the degreasing solution as described above, and then applying a voltage of 2 to 5 V for 5 to 30 minutes at a temperature of 50 to 80 ° C.

By the above pretreatment, that is, the degreasing process, impurities, as well as oil components and release agent materials can be effectively removed, which can increase the zinc substitution efficiency in the subsequent zinc substitution treatment step.

(2) zinc substitution step

After the pretreatment (immersion degreasing and electrolytic degreasing) as described above, zinc is substituted for the subject. At this time, it is preferable to perform the activation treatment prior to the zinc substitution. Activation treatment increases the zinc substitution efficiency. The activation treatment may be performed by immersing the subject in the treatment liquid and then activating the surface of the subject by, for example, holding the substrate at a temperature of 50 ° C. to 80 ° C. for 2 to 20 minutes. At this time, the treatment liquid used for the activation treatment may use an aqueous solution containing a treatment agent such as triethanolamine (TEA) 100 ~ 200g / L, based on 1 liter (L) of the total solution.

After performing the activation treatment as above, zinc is substituted for the subject. The zinc substitution may be carried out by depositing a subject in a zinc substitution treatment liquid and then maintaining it for 30 seconds to 5 minutes at a temperature of, for example, 80 to 100 ° C. At this time, the zinc replacement treatment solution, as an aqueous solution, containing a zinc precursor such as zinc sulfate, it is preferable to include potassium pyrophosphate 100 ~ 150g / L based on 1 liter (L) of the treatment solution. As described above, when potassium pyrophosphate is included in the zinc replacement treatment liquid, discoloration and deterioration of the surface of the subject may be prevented. According to a preferred embodiment, the zinc replacement treatment solution, based on 1 liter (L) of the treatment solution, zinc sulfate 25 ~ 35g / L, potassium pyrophosphate 100 ~ 150g / L, lithium fluoride 2 ~ 7g / L, sodium carbonate It is good to include 2 ~ 7g / L. When the zinc replacement treatment liquid is composed of such components and concentrations (contents), zinc replacement efficiency is good.

The zinc substitution treatment may be carried out over the first stage, but preferably, the second stage may be performed over the second stage. Specifically, the zinc substitution treatment, according to a preferred embodiment of the present invention, the first zinc substitution process (first zinc gating) to replace the zinc in the pretreated subject using a zinc substitution treatment solution; A zinc peeling process of peeling zinc of the first zinc-substituted object using a zinc peeling solution; And a second zinc substitution process (secondary zincate) in which zinc is substituted into the zinc-peeled object by using a zinc substitution treatment liquid. As described above, in the case of peeling off after the first substitution and then again replacing (secondary), the substitution efficiency of zinc is effectively increased. At this time, the first zinc substitution process and the second zinc substitution process using a zinc substitution treatment liquid of the same composition, as described above to maintain for 30 seconds to 5 minutes at a temperature of 80 ~ 100 ℃ Can proceed. And the zinc peeling process may be carried out by depositing the subject in the peeling solution, for example, the method for 10 seconds to 2 minutes at room temperature. At this time, the stripping solution includes hydrofluoric acid and nitric acid, it is preferable that the content of hydrofluoric acid is higher than nitric acid. Preferably, the stripper is an aqueous solution in which hydrofluoric acid and nitric acid are mixed at a weight ratio of 9: 1 to 9.9: 0.1 (fluoric acid: nitric acid).

(3) copper ( Cu A) plating step

After the zinc is substituted as above, copper (Cu) is plated. Adhesion with the ternary alloy plating layer may be increased by plating of copper (Cu). At this time, prior to copper (Cu) plating, it is good to perform a copper strike treatment on the zinc-substituted substrate. Copper plating efficiency may be increased by the copper strike treatment. The copper strike treatment may be performed by immersing a subject in a copper stripe solution, and then applying a voltage of 3 to 8V for 1 to 10 minutes at a temperature of 30 to 60 ° C. At this time, as the copper strike liquid, for example, an aqueous solution containing copper cyanide (CuCN) and / or sodium cyanide can be used. This copper strike treatment is an optional process, and copper plating may proceed immediately after the zinc substitution without the copper strike treatment.

Next, copper (Cu) is plated with respect to the copper strike processed member. Copper plating may be performed by immersing a subject in a copper plating solution, and then electroplating by applying a voltage of 2 to 5 V for 5 to 30 minutes at a temperature of 30 to 60 ° C. The copper (Cu) plating solution may be the same as the conventional one, and for example, a copper sulfate plating solution (aqueous solution) containing copper sulfate may be used. For example, the copper (Cu) plating solution, copper sulfate (Cu ₂ SO ₄ ) 150 ~ 220g / L, sulfuric acid (H ₂ SO ₄ ) 40 ~ 80g / L, sodium chloride based on 1 liter (L) of the plating solution An aqueous solution containing 80 to 120 mg / L (NaCl) and 2 to 10 ml / L of additive (CUBRAC 440 BASE) may be used.

(4) ternary alloy plating step

After plating copper (Cu) as above, the ternary alloy of Cu-Zn-Sn is plated on the surface of the conductor. Plating of the ternary alloy may be performed by immersing the subject in the ternary alloy plating solution and then electroplating for 5 to 30 minutes at a current density of 0.1 to 3 A / dm 2, for example. At this time, the ternary alloy plating solution uses the nickel-free (Ni-free) and cyan-free (CN-free) ternary alloy plating solutions of the present invention as described above.

According to the present invention described above, it is possible to implement a highly reliable metal surface. Specifically, it has excellent surface properties such as corrosion resistance, acid resistance, and abrasion resistance, and secures high reliability due to excellent adhesion between the conductor (base metal) and the ternary alloy plating layer (Cu-Zn-Sn). In addition, nickel-free (Ni-free) and cyan-free (CN-free) is environmentally friendly and harmless to the human body to overcome the barriers of environmental regulation.

Hereinafter, embodiments of the present invention will be exemplified. The following examples are merely provided to aid the understanding of the present invention, whereby the technical scope of the present invention is not limited.

[Example]

< Subject  Pretreatment>

Magnesium alloy was used as a to-be-contained metal. 1 is a photograph of the magnesium alloy (hereinafter referred to as 'test piece') used as a subject in the present embodiment.

First, the degreasing solution was bathed in order to pretreat the specimen. The degreasing liquid is an electrolyte solution containing no cyan, and 100 g / L sodium hydroxide, 100 g / L sodium carbonate, and 5 ml of ethoxylated nonlyphenol as a surfactant component based on 1 liter (L) of degreasing solution. An aqueous solution containing L was used.

After the specimen was immersed in the bath degreased liquid, it was maintained for 15 minutes at a temperature of 70 ℃ to perform the degreasing. Thereafter, after washing the specimen subjected to the immersion degreasing, electrolytic degreasing was performed using the same degreasing solution. Electrolytic degreasing was performed by immersing the specimen in an electrolytic degreasing bath containing degreasing liquid, and then applying a voltage of 3 V for 10 minutes at a temperature of 70 ° C.

The surface components of the specimens subjected to immersion and electrolytic degreasing were analyzed as described above. Figure 2a shows the surface component analysis results and photographs before degreasing, Figure 2b shows the surface component analysis results and photographs after degreasing. As can be seen in Figures 2a and 2b, it was confirmed that the release agent was removed by pretreatment through degreasing. Specifically, as shown in FIG. 2A, the Si component identified as the release agent material was analyzed for the specimen before degreasing, but the Si component was not analyzed until the electrolytic degreasing as shown in FIG. 2B.

On the other hand, in order to find out the degreasing efficiency according to the composition of the degreasing solution was performed an additional experiment in which the composition of the degreasing solution was different. That is, the concentration (content) of sodium hydroxide (NaOH) and surfactant (ethoxylated nonylphenol), which show the main effect of degreasing, were compared. In order to compare the degreasing efficiency, particles by concentration were counted by counting the number of particles together with the oil component, and the measurement was performed using a laser particle counter (LPC). The results are shown in the following [Table 1] and [Table 2]. Table 1 below contains 100 g / L sodium carbonate and 5 ml / L of surfactant (ethoxylated nonylphenol) based on 1 liter (L) of degreasing solution, and shows the concentration (content) of sodium hydroxide (NaOH). The results are measured differently, Table 2 below includes 100 g / L of sodium carbonate and 100 g / L of sodium hydroxide (NaOH) based on 1 liter (L) of degreasing solution, but is a surfactant (ethoxylated nonylphenol). This is the result of measuring different concentrations (contents).

<Evaluation of Degreasing Efficiency According to Concentration of Sodium Hydroxide (NaOH)> NaOH concentration 90 g / L 100 g / L 110 g / L Before degreasing (raw material)
Particle Number 1798 1862 1762 After deposition degreasing
number of particles 1148 852 784 Removal rate 36.15% 53.87% 55.51%

<Evaluation of Degreasing Efficiency According to Concentration of Surfactant> Concentration of surfactant 4ml / L 5ml / L 6ml / L Before degreasing (raw material)
Particle Number 1864 1907 1883 After deposition degreasing
number of particles 753 681 659 Removal rate 59.60% 63.30% 65.00%

As shown in [Table 1] and [Table 2], the degreasing efficiency (oil component removal rate) is improved as the concentration (content) of sodium hydroxide (NaOH) and surfactant (ethoxylated nonylphenol) increases. Could. In particular, as shown in [Table 2], it was found that the use of a surfactant (ethoxylated nonylphenol) showed a very improved degreasing efficiency (oil component removal rate) as 50% or more.

<Zinc Substitution>

As described above, the specimens pretreated (immersion degreasing and electrolytic degreasing) were subjected to zinc substitution treatment twice. In this case, prior to the zinc substitution treatment, the specimen was first activated. As a treatment liquid for the activation treatment, an aqueous solution containing 150 g / L of triethanolamine (TEA) was used based on 1 liter (L) of the total solution. The activation treatment was carried out by immersing the pretreated specimens in the activation treatment liquid at a temperature of 70 ° C. for 5 minutes.

Thereafter, the activated specimen was deposited on a zinc replacement treatment solution to carry out a first zinc replacement treatment. (1st jincate) With the zinc replacement treatment solution, sulfuric acid was treated based on one liter (L) of the treatment solution. An aqueous solution containing 30 g / L of zinc, 120 g / L of potassium pyrophosphate, 5 g / L of lithium fluoride and 5 g / L of sodium carbonate was used. The activated specimen was immersed in a zinc replacement treatment solution at a temperature of 90 ° C. for 1 minute to replace zinc on the surface of the specimen.

Figure 3a shows the results of the component analysis and photographs on the surface of the specimen subjected to the primary zinc substitution (primary zincate). As can be seen from the component analysis of FIG. 3A, it was confirmed that zinc was substituted on the surface of the specimen. In addition, Figure 3b is a photograph confirming the surface roughness of the specimen subjected to the first zinc substitution treatment (primary zinc gating) through the 3-Dimensional Interactive Display.

On the other hand, in order to determine the zinc substitution efficiency according to the composition of the zinc substitution treatment solution, zinc substitution efficiency was compared and evaluated by varying the concentration (content) of zinc sulfate (ZnSO ₄ ). The results are shown in the following [Table 3].

<Results of Evaluating Zinc Substitution Efficiency According to Concentration of Zinc Sulfate (ZnSO ₄ )> ZnSO ₄ concentration 20 g / L 25 g / L 30 g / L 35 g / L sample quantity 15ea 15ea 15ea 15ea Unplated Bad 11ea 5ea - - Unplated Rate 73% 33% 0% 0% evaluation Bad Bad Good Good

As shown in [Table 3], it was found that zinc substitution efficiency is good when zinc sulfate is included in 30g / L or more.

Next, a zinc peeling treatment was performed on the specimens subjected to the primary zinc substitution treatment (primary zinc gating). At this time, the peeling solution for zinc peeling, including hydrofluoric acid and nitric acid, was used an aqueous solution mixed with a weight ratio of hydrofluoric acid and nitric acid is 9: 1 (fluoric acid: nitric acid). Zinc stripping was performed by immersing the specimen in the stripping solution at room temperature for 20 seconds.

Figure 4 shows the results of the component analysis and photographs on the specimen surface after zinc peeling. As can be seen from the component analysis results of FIG. 4, zinc was not effectively detected after deposition in the stripping solution, thereby confirming that the zinc was effectively peeled.

Subsequently, the zinc-exfoliated specimens were deposited on the same zinc substitution treatment solution as above to undergo a second zinc substitution treatment.

Figure 5a shows the results of the component analysis and photographs on the specimen surface subjected to the secondary zinc substitution treatment (secondary jincate). As can be seen from the component analysis of FIG. 5A, it was confirmed that zinc was substituted on the surface of the specimen. In addition, Figure 5b is a photograph confirming the surface roughness of the specimen subjected to the secondary zinc substitution treatment (secondary jincate) through the 3-Dimensional Interactive Display. At this time, when comparing the result of the first zinc substitution treatment of FIGS. 3A and 3B and the result of the second zinc substitution treatment of FIGS. 5A and 5B, when the zinc substitution treatment was performed in two steps (FIGS. 5A and 5B). It can be seen that 5b) has more zinc components. Therefore, in the substitution treatment of zinc, after the first substitution treatment and then peeling off, the second zinc substitution treatment may confirm that the zinc substitution efficiency is high.

On the other hand, in the peeling solution for the zinc peeling, in order to determine the peeling efficiency according to the mixing ratio of hydrofluoric acid and nitric acid, the peeling state was compared and evaluated by varying the mixing ratio (weight ratio) of hydrofluoric acid and nitric acid. The results are shown in the following [Table 4].

Peeling Evaluation Results According to the Ratio of Hydrofluoric Acid and Nitric Acid Weight ratio
(Folic Acid: Nitric Acid) 7: 3 8: 2 9: 1 Peeling state Bad Slightly bad Good

As shown in [Table 4], as the ratio of hydrofluoric acid was increased, the peeling state was improved, and it was found that it was good when the ratio of hydrofluoric acid was 9 or more.

< Cu Plating>

Next, the second zinc-substituted specimens were copper strike treated. As the copper strike solution, an aqueous solution containing 20 g / L of copper cyanide (CuCN) and 35 g / L of sodium cyanide (NaCN) was used. The secondary zinc-substituted specimens were immersed in copper stripe solution and then a voltage of 5 V was applied at a temperature of 45 ° C. for 3 minutes.

Thereafter, copper plating was performed on the copper strike treated specimens. As a plating solution for copper (Cu) plating, a copper sulfate plating solution containing copper sulfate was used. Specifically, as the copper sulfate plating solution, based on 1 liter (L) of the plating solution, copper sulfate (Cu ₂ SO ₄ ) 192 g / L, sulfuric acid (H ₂ SO ₄ ) 60 g / L, sodium chloride (NaCl) 100 mg / L, and an additive ( CUBRAC 440 BASE) aqueous solution containing 4ml / L was used. Copper (Cu) plating was performed by an electrolytic plating method in which a copper strike-treated specimen was immersed in the copper sulfate plating solution, and then a voltage of 3 V was applied at a temperature of 45 ° C. for 10 minutes.

<3 element alloy plating>

Cu-Zn-Sn ternary alloy plating was performed on the copper plated specimens. At this time, the ternary alloy plating solution for ternary alloy plating, the copper oxide 22g / L, zinc oxide 1.3g / L, sodium carbonate 70g / L, sodium hydroxide 45g / L, hydroxide based on 1 liter (L) of the plating solution An aqueous solution containing 15 g / L of potassium, 10 ml / L of the first additive (aminoethylsulfonic acid) and 10 ml / L of the second additive (potassium carbonate) was used. The copper (Cu) plated specimen was immersed in the ternary alloy plating solution, and then subjected to electroplating for 10 minutes at a current density of 0.1 A / dm 2, whereby a ternary alloy of Cu—Zn—Sn was coated (plated). Completed the specimen.

The physical properties of the specimens surface-treated through the above process, that is, the specimens coated with a ternary alloy of Cu-Zn-Sn on the surface through the above process were evaluated as follows.

<Test Example 1>

In order to confirm the corrosion resistance of the surface-treated specimens, a salt spray test was conducted. 6a and 6b are test reports showing the results of the salt spray test.

The salt spray test is based on KS D 9502, saline solution for 5 hours or more under conditions of 5 wt% NaCl solution, test temperature 35 ± 0.5 ℃, spray pressure 0.098 ± 0.002 MPa, spray amount 1.5ml / h at 80cm2 It proceeded by exposure to the spray environment. In addition, the results of the salt spray test is shown in the following [Table 5]. As a result, it was evaluated that there was no corrosion after 48 hours of salt spraying.

<Fume spray test result> Brine concentration Test temperature Spray pressure Spray volume 5% NaCl (35 ± 0.5) ℃ (0.098 ± 0.002) MPa 1.5ml / h at 80 ℃ Test Items Criteria Test result Test Methods Salt Spray Test No corrosion after 48 hours of salt spray Satisfying criteria KS D 9502: 2009

<Second Test Example>

In order to confirm the reliability of the surface-treated specimens, acid resistance was tested. 7 is a test report showing the acid resistance test results.

Acid resistance evaluation was performed by immersion for 48 hours in pH 4.6 buffer based on KS D 8334. In addition, the acid resistance test results are shown in the following [Table 6]. As a result of the test, the surface of the specimen was evaluated to have excellent acid resistance.

<Acid resistance evaluation result> Test Items Test result Test Methods Acid resistance test
(48 hours) No discoloration pH 4.6 buffer
48 hours submersion

<Third Test Example>

In order to confirm the adhesion to the surface-treated specimens, abrasion resistance test and thermal shock test were conducted. 8 is a test report showing the wear resistance test results, Figure 9 is a test report showing the thermal shock test results.

The abrasion resistance test was conducted according to KS D 8335, and the thermal shock test was carried out in a total of 18 cycles with an image of 80 ° C for 2 hours and minus 40 ° C for 2 hours for 1 cycle. In addition, the wear resistance and thermal shock test results are shown in the following [Table 7] and [Table 8], respectively. As a result of the test, both wear resistance and thermal shock were evaluated to be good, and it was found that the adhesion of the ternary alloy plated film to the surface of the specimen was excellent.

<Evaluation of wear resistance evaluation> Test Items result Test Methods Abrasion resistance
(Taberized wear, CC-800 abrasive, 5N load) 1050 KS D 8335: 2001

<Thermal shock evaluation results> Test Items Test result Test Methods Appearance after thermal shock test clear 80 degrees 2 hours, -40 degrees 2 hours,
18 cycles in total

<4th test example>

In order to evaluate the environmental hazard of the surface-treated specimens, a nickel reaction test, a nickel dissolution test and a hazardous substance detection test were conducted. 10a and 10b is a test report showing the results of environmental hazard assessment.

The nickel reaction test was conducted in accordance with PD CR 12471, the nickel dissolution test in accordance with EN 1811, and the hazardous substance detection test in accordance with IEC 62321. In addition, the evaluation results are shown in the following [Table 9]. As a result, the nickel reaction test did not discolor, and the nickel dissolution test showed excellent results of 1.0 µg / cm 2 or less. In addition, the six hazardous substances such as lead, cadmium, mercury, hexavalent chromium, PBBs, and PBDs were not detected or detected below the allowable concentration of environmental regulations.

<Evaluation of Environmental Hazards> Test Items unit Test result Test Methods Nickel Spot Test - Negative PD CR 12471: 2002 Nickel emission amount ㎍ / (㎠ · week) 0.01 or less EN 1811: 1998 + A1: 2008 Lead (Pb) Mg / kg 35 IEC 62321: 2008
Test Equipment: ICP-OES Cadmium (Cd) Not detected (detection limit 1) IEC 62321: 2008
Test Equipment: ICP-OES Mercury (Hg) Not detected (detection limit 1) IEC 62321: 2008
Test Equipment: ICP-OES Hexavalent chromium (Cr ^{6 +} ) Voice (<0.02) IEC 62321: 2008
UV-Vis. Spectrophotometer PBBs Not detected (detection limit 5) IEC 62321: 2008
Test equipment: GC / MS PBDEs Not detected (detection limit 5) IEC 62321: 2008
Test equipment: GC / MS

<Fifth Test Example>

To examine the surface properties according to the compositional components of the ternary alloy plating solution, a comparative test was conducted as follows.

After the pretreated magnesium alloy specimen was immersed in the ternary alloy plating solution, electroplating was performed by applying a high current.

At this time, the ternary alloy plating solution was used for the comparison with the above Example, as a cyan compound containing a plating solution (containing cyan compound) as shown in Table 10 below. Psalm)

In addition, the plated by applying a high current in the same manner as above, the ternary alloy plating solution is carried out using the plating solution according to the embodiment of the present invention, which is composed of the components and contents as shown in the following [Table 10] (Example Specimen) 함량 The content of each component shown in the following [Table 10] is based on 1 liter (L) of the total plating solution.

Figure 11 shows the surface photograph of the specimen according to the Example and Comparative Example surface-treated with a different plating solution as described above (three-way alloy plating). As shown in FIG. 11, in the case of the specimen according to the comparative example, staining occurred due to the application of a high current, but in the case of the specimen according to the embodiment of the present invention, it was found that there was no staining and the gloss was excellent.

<The composition of ternary alloy plating solution> Comparative example Example ingredient Content (concentration) ingredient Content (concentration) Cu (CN) ₂ 22 g / L Cu ₂ O 22 g / L Zn (CN) ₂ 1.3 g / L ZnO 1.3 g / L Na ₂ O ₆ Sn 70 g / L Na ₂ SnO ₃ 4H ₂ O 70 g / L NaCN 45g / L NaOH 45g / L NaOH 15 g / L KOH 15 g / L First additive
(Aminoethylsulfonic acid) 10 ml / L First additive
(Aminoethylsulfonic acid) 10 ml / L Second additive
(KCN) 10 ml / L Second additive
(K ₂ CO ₃ ) 10 ml / L

As confirmed in the above test example, it can be seen that the specimens surface-treated according to the present invention are all excellent in physical properties, specifically corrosion resistance, acid resistance, adhesion (wear resistance, thermal shock resistance) required in the plating product. In addition, it also shows good results in the hazard evaluation, and it can be seen that it is environmentally friendly and harmless to human body as nickel-free (Ni-free) and cyan-free (CN-free). In addition, it can be seen that there is no staining and excellent surface glossiness as in the photo of FIG.

Claims (14)

A ternary alloy plating solution of Cu-Zn-Sn containing copper oxide, zinc oxide, sodium carbonate, a basic substance and aminoethylsulfonic acid.
The method of claim 1,
The ternary alloy plating solution of Cu-Zn-Sn, wherein the ternary alloy plating solution further comprises potassium carbonate.
The method of claim 1,
The basic material is a ternary alloy plating solution of Cu-Zn-Sn, characterized in that at least one selected from sodium hydroxide and potassium hydroxide.
The method of claim 1,
The ternary alloy plating solution is based on 1 liter (L) of the plating solution, 20 to 25 g / L copper oxide, 1.2 to 1.4 g / L zinc oxide, 65 to 80 g / L sodium carbonate, 52 to 70 g / L basic materials and A ternary alloy plating solution of Cu-Zn-Sn comprising 8 to 12 ml / L of aminoethylsulfonic acid.
The method of claim 2,
The ternary alloy plating solution, based on 1 liter (L) of the total plating solution, 20 to 25 g / L copper oxide, 1.2 to 1.4 g / L zinc oxide, 65 to 80 g / L sodium carbonate, 52 to 70 g / L basic substance, A ternary alloy plating solution of Cu-Zn-Sn, comprising 8 to 12 ml / L of aminoethylsulfonic acid and 8 to 12 ml / L of potassium carbonate.
The method of claim 3,
The ternary alloy plating solution, based on 1 liter (L) of the total plating solution, 20 to 25 g / L copper oxide, 1.2 to 1.4 g / L zinc oxide, 65 to 80 g / L sodium carbonate, 40 to 50 g / L sodium hydroxide, A ternary alloy plating solution of Cu-Zn-Sn, comprising 12 to 20 g / L potassium hydroxide, 8 to 12 ml / L aminoethylsulfonic acid, and 8 to 12 ml / L potassium carbonate.
A metal surface treatment method comprising the ternary alloy plating step of plating a ternary alloy of Cu-Zn-Sn on a subject by using the ternary alloy plating solution according to any one of claims 1 to 6.
A pretreatment step of pretreating the subject;
A zinc substitution step of replacing zinc with the pretreated subject using a zinc substitution treatment solution;
A copper plating step of plating copper on the zinc-substituted conductor; And
A metal surface comprising a ternary alloy plating step of plating a ternary alloy of Cu—Zn—Sn on a copper-plated conductor using the ternary alloy plating solution according to any one of claims 1 to 6. Treatment method.
9. The method of claim 8,
The pretreatment step may include at least one selected from an immersion degreasing step of depositing and degreasing the subject in a degreasing solution and an electrolytic degreasing step of electrolytic degreasing.
10. The method of claim 9,
The degreasing solution is a metal surface treatment method comprising 2 ~ 7ml / L surfactant based on a total of 1 liter (L) of degreasing solution.
9. The method of claim 8,
The zinc replacement treatment liquid, the surface treatment method, characterized in that it comprises 100 to 150 g / L of potassium pyrophosphate based on 1 liter (L) of the treatment liquid.
9. The method of claim 8,
The zinc substitution treatment liquid is based on 1 liter (L) of the total treatment liquid, zinc sulfate 25 ~ 35g / L, potassium pyrophosphate 100 ~ 150g / L, lithium fluoride 2 ~ 7g / L, sodium carbonate 2 ~ 7g / L Metal surface treatment method comprising a.
9. The method of claim 8,
The zinc substitution step,
A first zinc substitution process of substituting zinc in the pretreated subject using a zinc substitution treatment solution;
A zinc peeling process of peeling zinc of the first zinc-substituted object using a zinc peeling solution; And
And a second zinc substitution step of substituting zinc in the zinc-peeled object by using a zinc substitution treatment liquid.
The method of claim 13,
The zinc stripping solution comprises a hydrofluoric acid and nitric acid.

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